diff options
Diffstat (limited to 'drivers/tty/serial/sh-sci.c')
| -rw-r--r-- | drivers/tty/serial/sh-sci.c | 3521 |
1 files changed, 3521 insertions, 0 deletions
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c new file mode 100644 index 000000000..a7c28543c --- /dev/null +++ b/drivers/tty/serial/sh-sci.c @@ -0,0 +1,3521 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * SuperH on-chip serial module support. (SCI with no FIFO / with FIFO) + * + * Copyright (C) 2002 - 2011 Paul Mundt + * Copyright (C) 2015 Glider bvba + * Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007). + * + * based off of the old drivers/char/sh-sci.c by: + * + * Copyright (C) 1999, 2000 Niibe Yutaka + * Copyright (C) 2000 Sugioka Toshinobu + * Modified to support multiple serial ports. Stuart Menefy (May 2000). + * Modified to support SecureEdge. David McCullough (2002) + * Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003). + * Removed SH7300 support (Jul 2007). + */ +#undef DEBUG + +#include <linux/clk.h> +#include <linux/console.h> +#include <linux/ctype.h> +#include <linux/cpufreq.h> +#include <linux/delay.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/ioport.h> +#include <linux/ktime.h> +#include <linux/major.h> +#include <linux/minmax.h> +#include <linux/module.h> +#include <linux/mm.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/scatterlist.h> +#include <linux/serial.h> +#include <linux/serial_sci.h> +#include <linux/sh_dma.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/sysrq.h> +#include <linux/timer.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> + +#ifdef CONFIG_SUPERH +#include <asm/sh_bios.h> +#include <asm/platform_early.h> +#endif + +#include "serial_mctrl_gpio.h" +#include "sh-sci.h" + +/* Offsets into the sci_port->irqs array */ +enum { + SCIx_ERI_IRQ, + SCIx_RXI_IRQ, + SCIx_TXI_IRQ, + SCIx_BRI_IRQ, + SCIx_DRI_IRQ, + SCIx_TEI_IRQ, + SCIx_NR_IRQS, + + SCIx_MUX_IRQ = SCIx_NR_IRQS, /* special case */ +}; + +#define SCIx_IRQ_IS_MUXED(port) \ + ((port)->irqs[SCIx_ERI_IRQ] == \ + (port)->irqs[SCIx_RXI_IRQ]) || \ + ((port)->irqs[SCIx_ERI_IRQ] && \ + ((port)->irqs[SCIx_RXI_IRQ] < 0)) + +enum SCI_CLKS { + SCI_FCK, /* Functional Clock */ + SCI_SCK, /* Optional External Clock */ + SCI_BRG_INT, /* Optional BRG Internal Clock Source */ + SCI_SCIF_CLK, /* Optional BRG External Clock Source */ + SCI_NUM_CLKS +}; + +/* Bit x set means sampling rate x + 1 is supported */ +#define SCI_SR(x) BIT((x) - 1) +#define SCI_SR_RANGE(x, y) GENMASK((y) - 1, (x) - 1) + +#define SCI_SR_SCIFAB SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \ + SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \ + SCI_SR(19) | SCI_SR(27) + +#define min_sr(_port) ffs((_port)->sampling_rate_mask) +#define max_sr(_port) fls((_port)->sampling_rate_mask) + +/* Iterate over all supported sampling rates, from high to low */ +#define for_each_sr(_sr, _port) \ + for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--) \ + if ((_port)->sampling_rate_mask & SCI_SR((_sr))) + +struct plat_sci_reg { + u8 offset, size; +}; + +struct sci_port_params { + const struct plat_sci_reg regs[SCIx_NR_REGS]; + unsigned int fifosize; + unsigned int overrun_reg; + unsigned int overrun_mask; + unsigned int sampling_rate_mask; + unsigned int error_mask; + unsigned int error_clear; +}; + +struct sci_port { + struct uart_port port; + + /* Platform configuration */ + const struct sci_port_params *params; + const struct plat_sci_port *cfg; + unsigned int sampling_rate_mask; + resource_size_t reg_size; + struct mctrl_gpios *gpios; + + /* Clocks */ + struct clk *clks[SCI_NUM_CLKS]; + unsigned long clk_rates[SCI_NUM_CLKS]; + + int irqs[SCIx_NR_IRQS]; + char *irqstr[SCIx_NR_IRQS]; + + struct dma_chan *chan_tx; + struct dma_chan *chan_rx; + +#ifdef CONFIG_SERIAL_SH_SCI_DMA + struct dma_chan *chan_tx_saved; + struct dma_chan *chan_rx_saved; + dma_cookie_t cookie_tx; + dma_cookie_t cookie_rx[2]; + dma_cookie_t active_rx; + dma_addr_t tx_dma_addr; + unsigned int tx_dma_len; + struct scatterlist sg_rx[2]; + void *rx_buf[2]; + size_t buf_len_rx; + struct work_struct work_tx; + struct hrtimer rx_timer; + unsigned int rx_timeout; /* microseconds */ +#endif + unsigned int rx_frame; + int rx_trigger; + struct timer_list rx_fifo_timer; + int rx_fifo_timeout; + u16 hscif_tot; + + bool has_rtscts; + bool autorts; +}; + +#define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS + +static struct sci_port sci_ports[SCI_NPORTS]; +static unsigned long sci_ports_in_use; +static struct uart_driver sci_uart_driver; + +static inline struct sci_port * +to_sci_port(struct uart_port *uart) +{ + return container_of(uart, struct sci_port, port); +} + +static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = { + /* + * Common SCI definitions, dependent on the port's regshift + * value. + */ + [SCIx_SCI_REGTYPE] = { + .regs = { + [SCSMR] = { 0x00, 8 }, + [SCBRR] = { 0x01, 8 }, + [SCSCR] = { 0x02, 8 }, + [SCxTDR] = { 0x03, 8 }, + [SCxSR] = { 0x04, 8 }, + [SCxRDR] = { 0x05, 8 }, + }, + .fifosize = 1, + .overrun_reg = SCxSR, + .overrun_mask = SCI_ORER, + .sampling_rate_mask = SCI_SR(32), + .error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER, + .error_clear = SCI_ERROR_CLEAR & ~SCI_ORER, + }, + + /* + * Common definitions for legacy IrDA ports. + */ + [SCIx_IRDA_REGTYPE] = { + .regs = { + [SCSMR] = { 0x00, 8 }, + [SCBRR] = { 0x02, 8 }, + [SCSCR] = { 0x04, 8 }, + [SCxTDR] = { 0x06, 8 }, + [SCxSR] = { 0x08, 16 }, + [SCxRDR] = { 0x0a, 8 }, + [SCFCR] = { 0x0c, 8 }, + [SCFDR] = { 0x0e, 16 }, + }, + .fifosize = 1, + .overrun_reg = SCxSR, + .overrun_mask = SCI_ORER, + .sampling_rate_mask = SCI_SR(32), + .error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER, + .error_clear = SCI_ERROR_CLEAR & ~SCI_ORER, + }, + + /* + * Common SCIFA definitions. + */ + [SCIx_SCIFA_REGTYPE] = { + .regs = { + [SCSMR] = { 0x00, 16 }, + [SCBRR] = { 0x04, 8 }, + [SCSCR] = { 0x08, 16 }, + [SCxTDR] = { 0x20, 8 }, + [SCxSR] = { 0x14, 16 }, + [SCxRDR] = { 0x24, 8 }, + [SCFCR] = { 0x18, 16 }, + [SCFDR] = { 0x1c, 16 }, + [SCPCR] = { 0x30, 16 }, + [SCPDR] = { 0x34, 16 }, + }, + .fifosize = 64, + .overrun_reg = SCxSR, + .overrun_mask = SCIFA_ORER, + .sampling_rate_mask = SCI_SR_SCIFAB, + .error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER, + .error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER, + }, + + /* + * Common SCIFB definitions. + */ + [SCIx_SCIFB_REGTYPE] = { + .regs = { + [SCSMR] = { 0x00, 16 }, + [SCBRR] = { 0x04, 8 }, + [SCSCR] = { 0x08, 16 }, + [SCxTDR] = { 0x40, 8 }, + [SCxSR] = { 0x14, 16 }, + [SCxRDR] = { 0x60, 8 }, + [SCFCR] = { 0x18, 16 }, + [SCTFDR] = { 0x38, 16 }, + [SCRFDR] = { 0x3c, 16 }, + [SCPCR] = { 0x30, 16 }, + [SCPDR] = { 0x34, 16 }, + }, + .fifosize = 256, + .overrun_reg = SCxSR, + .overrun_mask = SCIFA_ORER, + .sampling_rate_mask = SCI_SR_SCIFAB, + .error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER, + .error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER, + }, + + /* + * Common SH-2(A) SCIF definitions for ports with FIFO data + * count registers. + */ + [SCIx_SH2_SCIF_FIFODATA_REGTYPE] = { + .regs = { + [SCSMR] = { 0x00, 16 }, + [SCBRR] = { 0x04, 8 }, + [SCSCR] = { 0x08, 16 }, + [SCxTDR] = { 0x0c, 8 }, + [SCxSR] = { 0x10, 16 }, + [SCxRDR] = { 0x14, 8 }, + [SCFCR] = { 0x18, 16 }, + [SCFDR] = { 0x1c, 16 }, + [SCSPTR] = { 0x20, 16 }, + [SCLSR] = { 0x24, 16 }, + }, + .fifosize = 16, + .overrun_reg = SCLSR, + .overrun_mask = SCLSR_ORER, + .sampling_rate_mask = SCI_SR(32), + .error_mask = SCIF_DEFAULT_ERROR_MASK, + .error_clear = SCIF_ERROR_CLEAR, + }, + + /* + * The "SCIFA" that is in RZ/T and RZ/A2. + * It looks like a normal SCIF with FIFO data, but with a + * compressed address space. Also, the break out of interrupts + * are different: ERI/BRI, RXI, TXI, TEI, DRI. + */ + [SCIx_RZ_SCIFA_REGTYPE] = { + .regs = { + [SCSMR] = { 0x00, 16 }, + [SCBRR] = { 0x02, 8 }, + [SCSCR] = { 0x04, 16 }, + [SCxTDR] = { 0x06, 8 }, + [SCxSR] = { 0x08, 16 }, + [SCxRDR] = { 0x0A, 8 }, + [SCFCR] = { 0x0C, 16 }, + [SCFDR] = { 0x0E, 16 }, + [SCSPTR] = { 0x10, 16 }, + [SCLSR] = { 0x12, 16 }, + }, + .fifosize = 16, + .overrun_reg = SCLSR, + .overrun_mask = SCLSR_ORER, + .sampling_rate_mask = SCI_SR(32), + .error_mask = SCIF_DEFAULT_ERROR_MASK, + .error_clear = SCIF_ERROR_CLEAR, + }, + + /* + * Common SH-3 SCIF definitions. + */ + [SCIx_SH3_SCIF_REGTYPE] = { + .regs = { + [SCSMR] = { 0x00, 8 }, + [SCBRR] = { 0x02, 8 }, + [SCSCR] = { 0x04, 8 }, + [SCxTDR] = { 0x06, 8 }, + [SCxSR] = { 0x08, 16 }, + [SCxRDR] = { 0x0a, 8 }, + [SCFCR] = { 0x0c, 8 }, + [SCFDR] = { 0x0e, 16 }, + }, + .fifosize = 16, + .overrun_reg = SCLSR, + .overrun_mask = SCLSR_ORER, + .sampling_rate_mask = SCI_SR(32), + .error_mask = SCIF_DEFAULT_ERROR_MASK, + .error_clear = SCIF_ERROR_CLEAR, + }, + + /* + * Common SH-4(A) SCIF(B) definitions. + */ + [SCIx_SH4_SCIF_REGTYPE] = { + .regs = { + [SCSMR] = { 0x00, 16 }, + [SCBRR] = { 0x04, 8 }, + [SCSCR] = { 0x08, 16 }, + [SCxTDR] = { 0x0c, 8 }, + [SCxSR] = { 0x10, 16 }, + [SCxRDR] = { 0x14, 8 }, + [SCFCR] = { 0x18, 16 }, + [SCFDR] = { 0x1c, 16 }, + [SCSPTR] = { 0x20, 16 }, + [SCLSR] = { 0x24, 16 }, + }, + .fifosize = 16, + .overrun_reg = SCLSR, + .overrun_mask = SCLSR_ORER, + .sampling_rate_mask = SCI_SR(32), + .error_mask = SCIF_DEFAULT_ERROR_MASK, + .error_clear = SCIF_ERROR_CLEAR, + }, + + /* + * Common SCIF definitions for ports with a Baud Rate Generator for + * External Clock (BRG). + */ + [SCIx_SH4_SCIF_BRG_REGTYPE] = { + .regs = { + [SCSMR] = { 0x00, 16 }, + [SCBRR] = { 0x04, 8 }, + [SCSCR] = { 0x08, 16 }, + [SCxTDR] = { 0x0c, 8 }, + [SCxSR] = { 0x10, 16 }, + [SCxRDR] = { 0x14, 8 }, + [SCFCR] = { 0x18, 16 }, + [SCFDR] = { 0x1c, 16 }, + [SCSPTR] = { 0x20, 16 }, + [SCLSR] = { 0x24, 16 }, + [SCDL] = { 0x30, 16 }, + [SCCKS] = { 0x34, 16 }, + }, + .fifosize = 16, + .overrun_reg = SCLSR, + .overrun_mask = SCLSR_ORER, + .sampling_rate_mask = SCI_SR(32), + .error_mask = SCIF_DEFAULT_ERROR_MASK, + .error_clear = SCIF_ERROR_CLEAR, + }, + + /* + * Common HSCIF definitions. + */ + [SCIx_HSCIF_REGTYPE] = { + .regs = { + [SCSMR] = { 0x00, 16 }, + [SCBRR] = { 0x04, 8 }, + [SCSCR] = { 0x08, 16 }, + [SCxTDR] = { 0x0c, 8 }, + [SCxSR] = { 0x10, 16 }, + [SCxRDR] = { 0x14, 8 }, + [SCFCR] = { 0x18, 16 }, + [SCFDR] = { 0x1c, 16 }, + [SCSPTR] = { 0x20, 16 }, + [SCLSR] = { 0x24, 16 }, + [HSSRR] = { 0x40, 16 }, + [SCDL] = { 0x30, 16 }, + [SCCKS] = { 0x34, 16 }, + [HSRTRGR] = { 0x54, 16 }, + [HSTTRGR] = { 0x58, 16 }, + }, + .fifosize = 128, + .overrun_reg = SCLSR, + .overrun_mask = SCLSR_ORER, + .sampling_rate_mask = SCI_SR_RANGE(8, 32), + .error_mask = SCIF_DEFAULT_ERROR_MASK, + .error_clear = SCIF_ERROR_CLEAR, + }, + + /* + * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR + * register. + */ + [SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = { + .regs = { + [SCSMR] = { 0x00, 16 }, + [SCBRR] = { 0x04, 8 }, + [SCSCR] = { 0x08, 16 }, + [SCxTDR] = { 0x0c, 8 }, + [SCxSR] = { 0x10, 16 }, + [SCxRDR] = { 0x14, 8 }, + [SCFCR] = { 0x18, 16 }, + [SCFDR] = { 0x1c, 16 }, + [SCLSR] = { 0x24, 16 }, + }, + .fifosize = 16, + .overrun_reg = SCLSR, + .overrun_mask = SCLSR_ORER, + .sampling_rate_mask = SCI_SR(32), + .error_mask = SCIF_DEFAULT_ERROR_MASK, + .error_clear = SCIF_ERROR_CLEAR, + }, + + /* + * Common SH-4(A) SCIF(B) definitions for ports with FIFO data + * count registers. + */ + [SCIx_SH4_SCIF_FIFODATA_REGTYPE] = { + .regs = { + [SCSMR] = { 0x00, 16 }, + [SCBRR] = { 0x04, 8 }, + [SCSCR] = { 0x08, 16 }, + [SCxTDR] = { 0x0c, 8 }, + [SCxSR] = { 0x10, 16 }, + [SCxRDR] = { 0x14, 8 }, + [SCFCR] = { 0x18, 16 }, + [SCFDR] = { 0x1c, 16 }, + [SCTFDR] = { 0x1c, 16 }, /* aliased to SCFDR */ + [SCRFDR] = { 0x20, 16 }, + [SCSPTR] = { 0x24, 16 }, + [SCLSR] = { 0x28, 16 }, + }, + .fifosize = 16, + .overrun_reg = SCLSR, + .overrun_mask = SCLSR_ORER, + .sampling_rate_mask = SCI_SR(32), + .error_mask = SCIF_DEFAULT_ERROR_MASK, + .error_clear = SCIF_ERROR_CLEAR, + }, + + /* + * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR + * registers. + */ + [SCIx_SH7705_SCIF_REGTYPE] = { + .regs = { + [SCSMR] = { 0x00, 16 }, + [SCBRR] = { 0x04, 8 }, + [SCSCR] = { 0x08, 16 }, + [SCxTDR] = { 0x20, 8 }, + [SCxSR] = { 0x14, 16 }, + [SCxRDR] = { 0x24, 8 }, + [SCFCR] = { 0x18, 16 }, + [SCFDR] = { 0x1c, 16 }, + }, + .fifosize = 64, + .overrun_reg = SCxSR, + .overrun_mask = SCIFA_ORER, + .sampling_rate_mask = SCI_SR(16), + .error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER, + .error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER, + }, +}; + +#define sci_getreg(up, offset) (&to_sci_port(up)->params->regs[offset]) + +/* + * The "offset" here is rather misleading, in that it refers to an enum + * value relative to the port mapping rather than the fixed offset + * itself, which needs to be manually retrieved from the platform's + * register map for the given port. + */ +static unsigned int sci_serial_in(struct uart_port *p, int offset) +{ + const struct plat_sci_reg *reg = sci_getreg(p, offset); + + if (reg->size == 8) + return ioread8(p->membase + (reg->offset << p->regshift)); + else if (reg->size == 16) + return ioread16(p->membase + (reg->offset << p->regshift)); + else + WARN(1, "Invalid register access\n"); + + return 0; +} + +static void sci_serial_out(struct uart_port *p, int offset, int value) +{ + const struct plat_sci_reg *reg = sci_getreg(p, offset); + + if (reg->size == 8) + iowrite8(value, p->membase + (reg->offset << p->regshift)); + else if (reg->size == 16) + iowrite16(value, p->membase + (reg->offset << p->regshift)); + else + WARN(1, "Invalid register access\n"); +} + +static void sci_port_enable(struct sci_port *sci_port) +{ + unsigned int i; + + if (!sci_port->port.dev) + return; + + pm_runtime_get_sync(sci_port->port.dev); + + for (i = 0; i < SCI_NUM_CLKS; i++) { + clk_prepare_enable(sci_port->clks[i]); + sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]); + } + sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK]; +} + +static void sci_port_disable(struct sci_port *sci_port) +{ + unsigned int i; + + if (!sci_port->port.dev) + return; + + for (i = SCI_NUM_CLKS; i-- > 0; ) + clk_disable_unprepare(sci_port->clks[i]); + + pm_runtime_put_sync(sci_port->port.dev); +} + +static inline unsigned long port_rx_irq_mask(struct uart_port *port) +{ + /* + * Not all ports (such as SCIFA) will support REIE. Rather than + * special-casing the port type, we check the port initialization + * IRQ enable mask to see whether the IRQ is desired at all. If + * it's unset, it's logically inferred that there's no point in + * testing for it. + */ + return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE); +} + +static void sci_start_tx(struct uart_port *port) +{ + struct sci_port *s = to_sci_port(port); + unsigned short ctrl; + +#ifdef CONFIG_SERIAL_SH_SCI_DMA + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { + u16 new, scr = serial_port_in(port, SCSCR); + if (s->chan_tx) + new = scr | SCSCR_TDRQE; + else + new = scr & ~SCSCR_TDRQE; + if (new != scr) + serial_port_out(port, SCSCR, new); + } + + if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) && + dma_submit_error(s->cookie_tx)) { + s->cookie_tx = 0; + schedule_work(&s->work_tx); + } +#endif + + if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) { + /* Set TIE (Transmit Interrupt Enable) bit in SCSCR */ + ctrl = serial_port_in(port, SCSCR); + serial_port_out(port, SCSCR, ctrl | SCSCR_TIE); + } +} + +static void sci_stop_tx(struct uart_port *port) +{ + unsigned short ctrl; + + /* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */ + ctrl = serial_port_in(port, SCSCR); + + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) + ctrl &= ~SCSCR_TDRQE; + + ctrl &= ~SCSCR_TIE; + + serial_port_out(port, SCSCR, ctrl); + +#ifdef CONFIG_SERIAL_SH_SCI_DMA + if (to_sci_port(port)->chan_tx && + !dma_submit_error(to_sci_port(port)->cookie_tx)) { + dmaengine_terminate_async(to_sci_port(port)->chan_tx); + to_sci_port(port)->cookie_tx = -EINVAL; + } +#endif +} + +static void sci_start_rx(struct uart_port *port) +{ + unsigned short ctrl; + + ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port); + + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) + ctrl &= ~SCSCR_RDRQE; + + serial_port_out(port, SCSCR, ctrl); +} + +static void sci_stop_rx(struct uart_port *port) +{ + unsigned short ctrl; + + ctrl = serial_port_in(port, SCSCR); + + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) + ctrl &= ~SCSCR_RDRQE; + + ctrl &= ~port_rx_irq_mask(port); + + serial_port_out(port, SCSCR, ctrl); +} + +static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask) +{ + if (port->type == PORT_SCI) { + /* Just store the mask */ + serial_port_out(port, SCxSR, mask); + } else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) { + /* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */ + /* Only clear the status bits we want to clear */ + serial_port_out(port, SCxSR, + serial_port_in(port, SCxSR) & mask); + } else { + /* Store the mask, clear parity/framing errors */ + serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC)); + } +} + +#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \ + defined(CONFIG_SERIAL_SH_SCI_EARLYCON) + +#ifdef CONFIG_CONSOLE_POLL +static int sci_poll_get_char(struct uart_port *port) +{ + unsigned short status; + int c; + + do { + status = serial_port_in(port, SCxSR); + if (status & SCxSR_ERRORS(port)) { + sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port)); + continue; + } + break; + } while (1); + + if (!(status & SCxSR_RDxF(port))) + return NO_POLL_CHAR; + + c = serial_port_in(port, SCxRDR); + + /* Dummy read */ + serial_port_in(port, SCxSR); + sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port)); + + return c; +} +#endif + +static void sci_poll_put_char(struct uart_port *port, unsigned char c) +{ + unsigned short status; + + do { + status = serial_port_in(port, SCxSR); + } while (!(status & SCxSR_TDxE(port))); + + serial_port_out(port, SCxTDR, c); + sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port)); +} +#endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE || + CONFIG_SERIAL_SH_SCI_EARLYCON */ + +static void sci_init_pins(struct uart_port *port, unsigned int cflag) +{ + struct sci_port *s = to_sci_port(port); + + /* + * Use port-specific handler if provided. + */ + if (s->cfg->ops && s->cfg->ops->init_pins) { + s->cfg->ops->init_pins(port, cflag); + return; + } + + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { + u16 data = serial_port_in(port, SCPDR); + u16 ctrl = serial_port_in(port, SCPCR); + + /* Enable RXD and TXD pin functions */ + ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC); + if (to_sci_port(port)->has_rtscts) { + /* RTS# is output, active low, unless autorts */ + if (!(port->mctrl & TIOCM_RTS)) { + ctrl |= SCPCR_RTSC; + data |= SCPDR_RTSD; + } else if (!s->autorts) { + ctrl |= SCPCR_RTSC; + data &= ~SCPDR_RTSD; + } else { + /* Enable RTS# pin function */ + ctrl &= ~SCPCR_RTSC; + } + /* Enable CTS# pin function */ + ctrl &= ~SCPCR_CTSC; + } + serial_port_out(port, SCPDR, data); + serial_port_out(port, SCPCR, ctrl); + } else if (sci_getreg(port, SCSPTR)->size) { + u16 status = serial_port_in(port, SCSPTR); + + /* RTS# is always output; and active low, unless autorts */ + status |= SCSPTR_RTSIO; + if (!(port->mctrl & TIOCM_RTS)) + status |= SCSPTR_RTSDT; + else if (!s->autorts) + status &= ~SCSPTR_RTSDT; + /* CTS# and SCK are inputs */ + status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO); + serial_port_out(port, SCSPTR, status); + } +} + +static int sci_txfill(struct uart_port *port) +{ + struct sci_port *s = to_sci_port(port); + unsigned int fifo_mask = (s->params->fifosize << 1) - 1; + const struct plat_sci_reg *reg; + + reg = sci_getreg(port, SCTFDR); + if (reg->size) + return serial_port_in(port, SCTFDR) & fifo_mask; + + reg = sci_getreg(port, SCFDR); + if (reg->size) + return serial_port_in(port, SCFDR) >> 8; + + return !(serial_port_in(port, SCxSR) & SCI_TDRE); +} + +static int sci_txroom(struct uart_port *port) +{ + return port->fifosize - sci_txfill(port); +} + +static int sci_rxfill(struct uart_port *port) +{ + struct sci_port *s = to_sci_port(port); + unsigned int fifo_mask = (s->params->fifosize << 1) - 1; + const struct plat_sci_reg *reg; + + reg = sci_getreg(port, SCRFDR); + if (reg->size) + return serial_port_in(port, SCRFDR) & fifo_mask; + + reg = sci_getreg(port, SCFDR); + if (reg->size) + return serial_port_in(port, SCFDR) & fifo_mask; + + return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0; +} + +/* ********************************************************************** * + * the interrupt related routines * + * ********************************************************************** */ + +static void sci_transmit_chars(struct uart_port *port) +{ + struct circ_buf *xmit = &port->state->xmit; + unsigned int stopped = uart_tx_stopped(port); + unsigned short status; + unsigned short ctrl; + int count; + + status = serial_port_in(port, SCxSR); + if (!(status & SCxSR_TDxE(port))) { + ctrl = serial_port_in(port, SCSCR); + if (uart_circ_empty(xmit)) + ctrl &= ~SCSCR_TIE; + else + ctrl |= SCSCR_TIE; + serial_port_out(port, SCSCR, ctrl); + return; + } + + count = sci_txroom(port); + + do { + unsigned char c; + + if (port->x_char) { + c = port->x_char; + port->x_char = 0; + } else if (!uart_circ_empty(xmit) && !stopped) { + c = xmit->buf[xmit->tail]; + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + } else { + break; + } + + serial_port_out(port, SCxTDR, c); + + port->icount.tx++; + } while (--count > 0); + + sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port)); + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); + if (uart_circ_empty(xmit)) + sci_stop_tx(port); + +} + +/* On SH3, SCIF may read end-of-break as a space->mark char */ +#define STEPFN(c) ({int __c = (c); (((__c-1)|(__c)) == -1); }) + +static void sci_receive_chars(struct uart_port *port) +{ + struct tty_port *tport = &port->state->port; + int i, count, copied = 0; + unsigned short status; + unsigned char flag; + + status = serial_port_in(port, SCxSR); + if (!(status & SCxSR_RDxF(port))) + return; + + while (1) { + /* Don't copy more bytes than there is room for in the buffer */ + count = tty_buffer_request_room(tport, sci_rxfill(port)); + + /* If for any reason we can't copy more data, we're done! */ + if (count == 0) + break; + + if (port->type == PORT_SCI) { + char c = serial_port_in(port, SCxRDR); + if (uart_handle_sysrq_char(port, c)) + count = 0; + else + tty_insert_flip_char(tport, c, TTY_NORMAL); + } else { + for (i = 0; i < count; i++) { + char c; + + if (port->type == PORT_SCIF || + port->type == PORT_HSCIF) { + status = serial_port_in(port, SCxSR); + c = serial_port_in(port, SCxRDR); + } else { + c = serial_port_in(port, SCxRDR); + status = serial_port_in(port, SCxSR); + } + if (uart_handle_sysrq_char(port, c)) { + count--; i--; + continue; + } + + /* Store data and status */ + if (status & SCxSR_FER(port)) { + flag = TTY_FRAME; + port->icount.frame++; + dev_notice(port->dev, "frame error\n"); + } else if (status & SCxSR_PER(port)) { + flag = TTY_PARITY; + port->icount.parity++; + dev_notice(port->dev, "parity error\n"); + } else + flag = TTY_NORMAL; + + tty_insert_flip_char(tport, c, flag); + } + } + + serial_port_in(port, SCxSR); /* dummy read */ + sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port)); + + copied += count; + port->icount.rx += count; + } + + if (copied) { + /* Tell the rest of the system the news. New characters! */ + tty_flip_buffer_push(tport); + } else { + /* TTY buffers full; read from RX reg to prevent lockup */ + serial_port_in(port, SCxRDR); + serial_port_in(port, SCxSR); /* dummy read */ + sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port)); + } +} + +static int sci_handle_errors(struct uart_port *port) +{ + int copied = 0; + unsigned short status = serial_port_in(port, SCxSR); + struct tty_port *tport = &port->state->port; + struct sci_port *s = to_sci_port(port); + + /* Handle overruns */ + if (status & s->params->overrun_mask) { + port->icount.overrun++; + + /* overrun error */ + if (tty_insert_flip_char(tport, 0, TTY_OVERRUN)) + copied++; + + dev_notice(port->dev, "overrun error\n"); + } + + if (status & SCxSR_FER(port)) { + /* frame error */ + port->icount.frame++; + + if (tty_insert_flip_char(tport, 0, TTY_FRAME)) + copied++; + + dev_notice(port->dev, "frame error\n"); + } + + if (status & SCxSR_PER(port)) { + /* parity error */ + port->icount.parity++; + + if (tty_insert_flip_char(tport, 0, TTY_PARITY)) + copied++; + + dev_notice(port->dev, "parity error\n"); + } + + if (copied) + tty_flip_buffer_push(tport); + + return copied; +} + +static int sci_handle_fifo_overrun(struct uart_port *port) +{ + struct tty_port *tport = &port->state->port; + struct sci_port *s = to_sci_port(port); + const struct plat_sci_reg *reg; + int copied = 0; + u16 status; + + reg = sci_getreg(port, s->params->overrun_reg); + if (!reg->size) + return 0; + + status = serial_port_in(port, s->params->overrun_reg); + if (status & s->params->overrun_mask) { + status &= ~s->params->overrun_mask; + serial_port_out(port, s->params->overrun_reg, status); + + port->icount.overrun++; + + tty_insert_flip_char(tport, 0, TTY_OVERRUN); + tty_flip_buffer_push(tport); + + dev_dbg(port->dev, "overrun error\n"); + copied++; + } + + return copied; +} + +static int sci_handle_breaks(struct uart_port *port) +{ + int copied = 0; + unsigned short status = serial_port_in(port, SCxSR); + struct tty_port *tport = &port->state->port; + + if (uart_handle_break(port)) + return 0; + + if (status & SCxSR_BRK(port)) { + port->icount.brk++; + + /* Notify of BREAK */ + if (tty_insert_flip_char(tport, 0, TTY_BREAK)) + copied++; + + dev_dbg(port->dev, "BREAK detected\n"); + } + + if (copied) + tty_flip_buffer_push(tport); + + copied += sci_handle_fifo_overrun(port); + + return copied; +} + +static int scif_set_rtrg(struct uart_port *port, int rx_trig) +{ + unsigned int bits; + + if (rx_trig >= port->fifosize) + rx_trig = port->fifosize - 1; + if (rx_trig < 1) + rx_trig = 1; + + /* HSCIF can be set to an arbitrary level. */ + if (sci_getreg(port, HSRTRGR)->size) { + serial_port_out(port, HSRTRGR, rx_trig); + return rx_trig; + } + + switch (port->type) { + case PORT_SCIF: + if (rx_trig < 4) { + bits = 0; + rx_trig = 1; + } else if (rx_trig < 8) { + bits = SCFCR_RTRG0; + rx_trig = 4; + } else if (rx_trig < 14) { + bits = SCFCR_RTRG1; + rx_trig = 8; + } else { + bits = SCFCR_RTRG0 | SCFCR_RTRG1; + rx_trig = 14; + } + break; + case PORT_SCIFA: + case PORT_SCIFB: + if (rx_trig < 16) { + bits = 0; + rx_trig = 1; + } else if (rx_trig < 32) { + bits = SCFCR_RTRG0; + rx_trig = 16; + } else if (rx_trig < 48) { + bits = SCFCR_RTRG1; + rx_trig = 32; + } else { + bits = SCFCR_RTRG0 | SCFCR_RTRG1; + rx_trig = 48; + } + break; + default: + WARN(1, "unknown FIFO configuration"); + return 1; + } + + serial_port_out(port, SCFCR, + (serial_port_in(port, SCFCR) & + ~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits); + + return rx_trig; +} + +static int scif_rtrg_enabled(struct uart_port *port) +{ + if (sci_getreg(port, HSRTRGR)->size) + return serial_port_in(port, HSRTRGR) != 0; + else + return (serial_port_in(port, SCFCR) & + (SCFCR_RTRG0 | SCFCR_RTRG1)) != 0; +} + +static void rx_fifo_timer_fn(struct timer_list *t) +{ + struct sci_port *s = from_timer(s, t, rx_fifo_timer); + struct uart_port *port = &s->port; + + dev_dbg(port->dev, "Rx timed out\n"); + scif_set_rtrg(port, 1); +} + +static ssize_t rx_fifo_trigger_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct uart_port *port = dev_get_drvdata(dev); + struct sci_port *sci = to_sci_port(port); + + return sprintf(buf, "%d\n", sci->rx_trigger); +} + +static ssize_t rx_fifo_trigger_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct uart_port *port = dev_get_drvdata(dev); + struct sci_port *sci = to_sci_port(port); + int ret; + long r; + + ret = kstrtol(buf, 0, &r); + if (ret) + return ret; + + sci->rx_trigger = scif_set_rtrg(port, r); + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) + scif_set_rtrg(port, 1); + + return count; +} + +static DEVICE_ATTR_RW(rx_fifo_trigger); + +static ssize_t rx_fifo_timeout_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct uart_port *port = dev_get_drvdata(dev); + struct sci_port *sci = to_sci_port(port); + int v; + + if (port->type == PORT_HSCIF) + v = sci->hscif_tot >> HSSCR_TOT_SHIFT; + else + v = sci->rx_fifo_timeout; + + return sprintf(buf, "%d\n", v); +} + +static ssize_t rx_fifo_timeout_store(struct device *dev, + struct device_attribute *attr, + const char *buf, + size_t count) +{ + struct uart_port *port = dev_get_drvdata(dev); + struct sci_port *sci = to_sci_port(port); + int ret; + long r; + + ret = kstrtol(buf, 0, &r); + if (ret) + return ret; + + if (port->type == PORT_HSCIF) { + if (r < 0 || r > 3) + return -EINVAL; + sci->hscif_tot = r << HSSCR_TOT_SHIFT; + } else { + sci->rx_fifo_timeout = r; + scif_set_rtrg(port, 1); + if (r > 0) + timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0); + } + + return count; +} + +static DEVICE_ATTR_RW(rx_fifo_timeout); + + +#ifdef CONFIG_SERIAL_SH_SCI_DMA +static void sci_dma_tx_complete(void *arg) +{ + struct sci_port *s = arg; + struct uart_port *port = &s->port; + struct circ_buf *xmit = &port->state->xmit; + unsigned long flags; + + dev_dbg(port->dev, "%s(%d)\n", __func__, port->line); + + spin_lock_irqsave(&port->lock, flags); + + xmit->tail += s->tx_dma_len; + xmit->tail &= UART_XMIT_SIZE - 1; + + port->icount.tx += s->tx_dma_len; + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); + + if (!uart_circ_empty(xmit)) { + s->cookie_tx = 0; + schedule_work(&s->work_tx); + } else { + s->cookie_tx = -EINVAL; + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { + u16 ctrl = serial_port_in(port, SCSCR); + serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE); + } + } + + spin_unlock_irqrestore(&port->lock, flags); +} + +/* Locking: called with port lock held */ +static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count) +{ + struct uart_port *port = &s->port; + struct tty_port *tport = &port->state->port; + int copied; + + copied = tty_insert_flip_string(tport, buf, count); + if (copied < count) + port->icount.buf_overrun++; + + port->icount.rx += copied; + + return copied; +} + +static int sci_dma_rx_find_active(struct sci_port *s) +{ + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++) + if (s->active_rx == s->cookie_rx[i]) + return i; + + return -1; +} + +static void sci_dma_rx_chan_invalidate(struct sci_port *s) +{ + unsigned int i; + + s->chan_rx = NULL; + for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++) + s->cookie_rx[i] = -EINVAL; + s->active_rx = 0; +} + +static void sci_dma_rx_release(struct sci_port *s) +{ + struct dma_chan *chan = s->chan_rx_saved; + + s->chan_rx_saved = NULL; + sci_dma_rx_chan_invalidate(s); + dmaengine_terminate_sync(chan); + dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0], + sg_dma_address(&s->sg_rx[0])); + dma_release_channel(chan); +} + +static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec) +{ + long sec = usec / 1000000; + long nsec = (usec % 1000000) * 1000; + ktime_t t = ktime_set(sec, nsec); + + hrtimer_start(hrt, t, HRTIMER_MODE_REL); +} + +static void sci_dma_rx_reenable_irq(struct sci_port *s) +{ + struct uart_port *port = &s->port; + u16 scr; + + /* Direct new serial port interrupts back to CPU */ + scr = serial_port_in(port, SCSCR); + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { + scr &= ~SCSCR_RDRQE; + enable_irq(s->irqs[SCIx_RXI_IRQ]); + } + serial_port_out(port, SCSCR, scr | SCSCR_RIE); +} + +static void sci_dma_rx_complete(void *arg) +{ + struct sci_port *s = arg; + struct dma_chan *chan = s->chan_rx; + struct uart_port *port = &s->port; + struct dma_async_tx_descriptor *desc; + unsigned long flags; + int active, count = 0; + + dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line, + s->active_rx); + + spin_lock_irqsave(&port->lock, flags); + + active = sci_dma_rx_find_active(s); + if (active >= 0) + count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx); + + start_hrtimer_us(&s->rx_timer, s->rx_timeout); + + if (count) + tty_flip_buffer_push(&port->state->port); + + desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1, + DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) + goto fail; + + desc->callback = sci_dma_rx_complete; + desc->callback_param = s; + s->cookie_rx[active] = dmaengine_submit(desc); + if (dma_submit_error(s->cookie_rx[active])) + goto fail; + + s->active_rx = s->cookie_rx[!active]; + + dma_async_issue_pending(chan); + + spin_unlock_irqrestore(&port->lock, flags); + dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n", + __func__, s->cookie_rx[active], active, s->active_rx); + return; + +fail: + spin_unlock_irqrestore(&port->lock, flags); + dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n"); + /* Switch to PIO */ + spin_lock_irqsave(&port->lock, flags); + dmaengine_terminate_async(chan); + sci_dma_rx_chan_invalidate(s); + sci_dma_rx_reenable_irq(s); + spin_unlock_irqrestore(&port->lock, flags); +} + +static void sci_dma_tx_release(struct sci_port *s) +{ + struct dma_chan *chan = s->chan_tx_saved; + + cancel_work_sync(&s->work_tx); + s->chan_tx_saved = s->chan_tx = NULL; + s->cookie_tx = -EINVAL; + dmaengine_terminate_sync(chan); + dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE, + DMA_TO_DEVICE); + dma_release_channel(chan); +} + +static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held) +{ + struct dma_chan *chan = s->chan_rx; + struct uart_port *port = &s->port; + unsigned long flags; + int i; + + for (i = 0; i < 2; i++) { + struct scatterlist *sg = &s->sg_rx[i]; + struct dma_async_tx_descriptor *desc; + + desc = dmaengine_prep_slave_sg(chan, + sg, 1, DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) + goto fail; + + desc->callback = sci_dma_rx_complete; + desc->callback_param = s; + s->cookie_rx[i] = dmaengine_submit(desc); + if (dma_submit_error(s->cookie_rx[i])) + goto fail; + + } + + s->active_rx = s->cookie_rx[0]; + + dma_async_issue_pending(chan); + return 0; + +fail: + /* Switch to PIO */ + if (!port_lock_held) + spin_lock_irqsave(&port->lock, flags); + if (i) + dmaengine_terminate_async(chan); + sci_dma_rx_chan_invalidate(s); + sci_start_rx(port); + if (!port_lock_held) + spin_unlock_irqrestore(&port->lock, flags); + return -EAGAIN; +} + +static void sci_dma_tx_work_fn(struct work_struct *work) +{ + struct sci_port *s = container_of(work, struct sci_port, work_tx); + struct dma_async_tx_descriptor *desc; + struct dma_chan *chan = s->chan_tx; + struct uart_port *port = &s->port; + struct circ_buf *xmit = &port->state->xmit; + unsigned long flags; + dma_addr_t buf; + int head, tail; + + /* + * DMA is idle now. + * Port xmit buffer is already mapped, and it is one page... Just adjust + * offsets and lengths. Since it is a circular buffer, we have to + * transmit till the end, and then the rest. Take the port lock to get a + * consistent xmit buffer state. + */ + spin_lock_irq(&port->lock); + head = xmit->head; + tail = xmit->tail; + buf = s->tx_dma_addr + (tail & (UART_XMIT_SIZE - 1)); + s->tx_dma_len = min_t(unsigned int, + CIRC_CNT(head, tail, UART_XMIT_SIZE), + CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE)); + if (!s->tx_dma_len) { + /* Transmit buffer has been flushed */ + spin_unlock_irq(&port->lock); + return; + } + + desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len, + DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) { + spin_unlock_irq(&port->lock); + dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n"); + goto switch_to_pio; + } + + dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len, + DMA_TO_DEVICE); + + desc->callback = sci_dma_tx_complete; + desc->callback_param = s; + s->cookie_tx = dmaengine_submit(desc); + if (dma_submit_error(s->cookie_tx)) { + spin_unlock_irq(&port->lock); + dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n"); + goto switch_to_pio; + } + + spin_unlock_irq(&port->lock); + dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n", + __func__, xmit->buf, tail, head, s->cookie_tx); + + dma_async_issue_pending(chan); + return; + +switch_to_pio: + spin_lock_irqsave(&port->lock, flags); + s->chan_tx = NULL; + sci_start_tx(port); + spin_unlock_irqrestore(&port->lock, flags); + return; +} + +static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t) +{ + struct sci_port *s = container_of(t, struct sci_port, rx_timer); + struct dma_chan *chan = s->chan_rx; + struct uart_port *port = &s->port; + struct dma_tx_state state; + enum dma_status status; + unsigned long flags; + unsigned int read; + int active, count; + + dev_dbg(port->dev, "DMA Rx timed out\n"); + + spin_lock_irqsave(&port->lock, flags); + + active = sci_dma_rx_find_active(s); + if (active < 0) { + spin_unlock_irqrestore(&port->lock, flags); + return HRTIMER_NORESTART; + } + + status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state); + if (status == DMA_COMPLETE) { + spin_unlock_irqrestore(&port->lock, flags); + dev_dbg(port->dev, "Cookie %d #%d has already completed\n", + s->active_rx, active); + + /* Let packet complete handler take care of the packet */ + return HRTIMER_NORESTART; + } + + dmaengine_pause(chan); + + /* + * sometimes DMA transfer doesn't stop even if it is stopped and + * data keeps on coming until transaction is complete so check + * for DMA_COMPLETE again + * Let packet complete handler take care of the packet + */ + status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state); + if (status == DMA_COMPLETE) { + spin_unlock_irqrestore(&port->lock, flags); + dev_dbg(port->dev, "Transaction complete after DMA engine was stopped"); + return HRTIMER_NORESTART; + } + + /* Handle incomplete DMA receive */ + dmaengine_terminate_async(s->chan_rx); + read = sg_dma_len(&s->sg_rx[active]) - state.residue; + + if (read) { + count = sci_dma_rx_push(s, s->rx_buf[active], read); + if (count) + tty_flip_buffer_push(&port->state->port); + } + + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) + sci_dma_rx_submit(s, true); + + sci_dma_rx_reenable_irq(s); + + spin_unlock_irqrestore(&port->lock, flags); + + return HRTIMER_NORESTART; +} + +static struct dma_chan *sci_request_dma_chan(struct uart_port *port, + enum dma_transfer_direction dir) +{ + struct dma_chan *chan; + struct dma_slave_config cfg; + int ret; + + chan = dma_request_slave_channel(port->dev, + dir == DMA_MEM_TO_DEV ? "tx" : "rx"); + if (!chan) { + dev_dbg(port->dev, "dma_request_slave_channel failed\n"); + return NULL; + } + + memset(&cfg, 0, sizeof(cfg)); + cfg.direction = dir; + if (dir == DMA_MEM_TO_DEV) { + cfg.dst_addr = port->mapbase + + (sci_getreg(port, SCxTDR)->offset << port->regshift); + cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + } else { + cfg.src_addr = port->mapbase + + (sci_getreg(port, SCxRDR)->offset << port->regshift); + cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + } + + ret = dmaengine_slave_config(chan, &cfg); + if (ret) { + dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret); + dma_release_channel(chan); + return NULL; + } + + return chan; +} + +static void sci_request_dma(struct uart_port *port) +{ + struct sci_port *s = to_sci_port(port); + struct dma_chan *chan; + + dev_dbg(port->dev, "%s: port %d\n", __func__, port->line); + + /* + * DMA on console may interfere with Kernel log messages which use + * plain putchar(). So, simply don't use it with a console. + */ + if (uart_console(port)) + return; + + if (!port->dev->of_node) + return; + + s->cookie_tx = -EINVAL; + + /* + * Don't request a dma channel if no channel was specified + * in the device tree. + */ + if (!of_find_property(port->dev->of_node, "dmas", NULL)) + return; + + chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV); + dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan); + if (chan) { + /* UART circular tx buffer is an aligned page. */ + s->tx_dma_addr = dma_map_single(chan->device->dev, + port->state->xmit.buf, + UART_XMIT_SIZE, + DMA_TO_DEVICE); + if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) { + dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n"); + dma_release_channel(chan); + } else { + dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n", + __func__, UART_XMIT_SIZE, + port->state->xmit.buf, &s->tx_dma_addr); + + INIT_WORK(&s->work_tx, sci_dma_tx_work_fn); + s->chan_tx_saved = s->chan_tx = chan; + } + } + + chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM); + dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan); + if (chan) { + unsigned int i; + dma_addr_t dma; + void *buf; + + s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize); + buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2, + &dma, GFP_KERNEL); + if (!buf) { + dev_warn(port->dev, + "Failed to allocate Rx dma buffer, using PIO\n"); + dma_release_channel(chan); + return; + } + + for (i = 0; i < 2; i++) { + struct scatterlist *sg = &s->sg_rx[i]; + + sg_init_table(sg, 1); + s->rx_buf[i] = buf; + sg_dma_address(sg) = dma; + sg_dma_len(sg) = s->buf_len_rx; + + buf += s->buf_len_rx; + dma += s->buf_len_rx; + } + + hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + s->rx_timer.function = sci_dma_rx_timer_fn; + + s->chan_rx_saved = s->chan_rx = chan; + + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) + sci_dma_rx_submit(s, false); + } +} + +static void sci_free_dma(struct uart_port *port) +{ + struct sci_port *s = to_sci_port(port); + + if (s->chan_tx_saved) + sci_dma_tx_release(s); + if (s->chan_rx_saved) + sci_dma_rx_release(s); +} + +static void sci_flush_buffer(struct uart_port *port) +{ + struct sci_port *s = to_sci_port(port); + + /* + * In uart_flush_buffer(), the xmit circular buffer has just been + * cleared, so we have to reset tx_dma_len accordingly, and stop any + * pending transfers + */ + s->tx_dma_len = 0; + if (s->chan_tx) { + dmaengine_terminate_async(s->chan_tx); + s->cookie_tx = -EINVAL; + } +} +#else /* !CONFIG_SERIAL_SH_SCI_DMA */ +static inline void sci_request_dma(struct uart_port *port) +{ +} + +static inline void sci_free_dma(struct uart_port *port) +{ +} + +#define sci_flush_buffer NULL +#endif /* !CONFIG_SERIAL_SH_SCI_DMA */ + +static irqreturn_t sci_rx_interrupt(int irq, void *ptr) +{ + struct uart_port *port = ptr; + struct sci_port *s = to_sci_port(port); + +#ifdef CONFIG_SERIAL_SH_SCI_DMA + if (s->chan_rx) { + u16 scr = serial_port_in(port, SCSCR); + u16 ssr = serial_port_in(port, SCxSR); + + /* Disable future Rx interrupts */ + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { + disable_irq_nosync(irq); + scr |= SCSCR_RDRQE; + } else { + if (sci_dma_rx_submit(s, false) < 0) + goto handle_pio; + + scr &= ~SCSCR_RIE; + } + serial_port_out(port, SCSCR, scr); + /* Clear current interrupt */ + serial_port_out(port, SCxSR, + ssr & ~(SCIF_DR | SCxSR_RDxF(port))); + dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n", + jiffies, s->rx_timeout); + start_hrtimer_us(&s->rx_timer, s->rx_timeout); + + return IRQ_HANDLED; + } + +handle_pio: +#endif + + if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) { + if (!scif_rtrg_enabled(port)) + scif_set_rtrg(port, s->rx_trigger); + + mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP( + s->rx_frame * HZ * s->rx_fifo_timeout, 1000000)); + } + + /* I think sci_receive_chars has to be called irrespective + * of whether the I_IXOFF is set, otherwise, how is the interrupt + * to be disabled? + */ + sci_receive_chars(port); + + return IRQ_HANDLED; +} + +static irqreturn_t sci_tx_interrupt(int irq, void *ptr) +{ + struct uart_port *port = ptr; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + sci_transmit_chars(port); + spin_unlock_irqrestore(&port->lock, flags); + + return IRQ_HANDLED; +} + +static irqreturn_t sci_br_interrupt(int irq, void *ptr) +{ + struct uart_port *port = ptr; + + /* Handle BREAKs */ + sci_handle_breaks(port); + + /* drop invalid character received before break was detected */ + serial_port_in(port, SCxRDR); + + sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port)); + + return IRQ_HANDLED; +} + +static irqreturn_t sci_er_interrupt(int irq, void *ptr) +{ + struct uart_port *port = ptr; + struct sci_port *s = to_sci_port(port); + + if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) { + /* Break and Error interrupts are muxed */ + unsigned short ssr_status = serial_port_in(port, SCxSR); + + /* Break Interrupt */ + if (ssr_status & SCxSR_BRK(port)) + sci_br_interrupt(irq, ptr); + + /* Break only? */ + if (!(ssr_status & SCxSR_ERRORS(port))) + return IRQ_HANDLED; + } + + /* Handle errors */ + if (port->type == PORT_SCI) { + if (sci_handle_errors(port)) { + /* discard character in rx buffer */ + serial_port_in(port, SCxSR); + sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port)); + } + } else { + sci_handle_fifo_overrun(port); + if (!s->chan_rx) + sci_receive_chars(port); + } + + sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port)); + + /* Kick the transmission */ + if (!s->chan_tx) + sci_tx_interrupt(irq, ptr); + + return IRQ_HANDLED; +} + +static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr) +{ + unsigned short ssr_status, scr_status, err_enabled, orer_status = 0; + struct uart_port *port = ptr; + struct sci_port *s = to_sci_port(port); + irqreturn_t ret = IRQ_NONE; + + ssr_status = serial_port_in(port, SCxSR); + scr_status = serial_port_in(port, SCSCR); + if (s->params->overrun_reg == SCxSR) + orer_status = ssr_status; + else if (sci_getreg(port, s->params->overrun_reg)->size) + orer_status = serial_port_in(port, s->params->overrun_reg); + + err_enabled = scr_status & port_rx_irq_mask(port); + + /* Tx Interrupt */ + if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) && + !s->chan_tx) + ret = sci_tx_interrupt(irq, ptr); + + /* + * Rx Interrupt: if we're using DMA, the DMA controller clears RDF / + * DR flags + */ + if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) && + (scr_status & SCSCR_RIE)) + ret = sci_rx_interrupt(irq, ptr); + + /* Error Interrupt */ + if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled) + ret = sci_er_interrupt(irq, ptr); + + /* Break Interrupt */ + if (s->irqs[SCIx_ERI_IRQ] != s->irqs[SCIx_BRI_IRQ] && + (ssr_status & SCxSR_BRK(port)) && err_enabled) + ret = sci_br_interrupt(irq, ptr); + + /* Overrun Interrupt */ + if (orer_status & s->params->overrun_mask) { + sci_handle_fifo_overrun(port); + ret = IRQ_HANDLED; + } + + return ret; +} + +static const struct sci_irq_desc { + const char *desc; + irq_handler_t handler; +} sci_irq_desc[] = { + /* + * Split out handlers, the default case. + */ + [SCIx_ERI_IRQ] = { + .desc = "rx err", + .handler = sci_er_interrupt, + }, + + [SCIx_RXI_IRQ] = { + .desc = "rx full", + .handler = sci_rx_interrupt, + }, + + [SCIx_TXI_IRQ] = { + .desc = "tx empty", + .handler = sci_tx_interrupt, + }, + + [SCIx_BRI_IRQ] = { + .desc = "break", + .handler = sci_br_interrupt, + }, + + [SCIx_DRI_IRQ] = { + .desc = "rx ready", + .handler = sci_rx_interrupt, + }, + + [SCIx_TEI_IRQ] = { + .desc = "tx end", + .handler = sci_tx_interrupt, + }, + + /* + * Special muxed handler. + */ + [SCIx_MUX_IRQ] = { + .desc = "mux", + .handler = sci_mpxed_interrupt, + }, +}; + +static int sci_request_irq(struct sci_port *port) +{ + struct uart_port *up = &port->port; + int i, j, w, ret = 0; + + for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) { + const struct sci_irq_desc *desc; + int irq; + + /* Check if already registered (muxed) */ + for (w = 0; w < i; w++) + if (port->irqs[w] == port->irqs[i]) + w = i + 1; + if (w > i) + continue; + + if (SCIx_IRQ_IS_MUXED(port)) { + i = SCIx_MUX_IRQ; + irq = up->irq; + } else { + irq = port->irqs[i]; + + /* + * Certain port types won't support all of the + * available interrupt sources. + */ + if (unlikely(irq < 0)) + continue; + } + + desc = sci_irq_desc + i; + port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s", + dev_name(up->dev), desc->desc); + if (!port->irqstr[j]) { + ret = -ENOMEM; + goto out_nomem; + } + + ret = request_irq(irq, desc->handler, up->irqflags, + port->irqstr[j], port); + if (unlikely(ret)) { + dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc); + goto out_noirq; + } + } + + return 0; + +out_noirq: + while (--i >= 0) + free_irq(port->irqs[i], port); + +out_nomem: + while (--j >= 0) + kfree(port->irqstr[j]); + + return ret; +} + +static void sci_free_irq(struct sci_port *port) +{ + int i, j; + + /* + * Intentionally in reverse order so we iterate over the muxed + * IRQ first. + */ + for (i = 0; i < SCIx_NR_IRQS; i++) { + int irq = port->irqs[i]; + + /* + * Certain port types won't support all of the available + * interrupt sources. + */ + if (unlikely(irq < 0)) + continue; + + /* Check if already freed (irq was muxed) */ + for (j = 0; j < i; j++) + if (port->irqs[j] == irq) + j = i + 1; + if (j > i) + continue; + + free_irq(port->irqs[i], port); + kfree(port->irqstr[i]); + + if (SCIx_IRQ_IS_MUXED(port)) { + /* If there's only one IRQ, we're done. */ + return; + } + } +} + +static unsigned int sci_tx_empty(struct uart_port *port) +{ + unsigned short status = serial_port_in(port, SCxSR); + unsigned short in_tx_fifo = sci_txfill(port); + + return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0; +} + +static void sci_set_rts(struct uart_port *port, bool state) +{ + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { + u16 data = serial_port_in(port, SCPDR); + + /* Active low */ + if (state) + data &= ~SCPDR_RTSD; + else + data |= SCPDR_RTSD; + serial_port_out(port, SCPDR, data); + + /* RTS# is output */ + serial_port_out(port, SCPCR, + serial_port_in(port, SCPCR) | SCPCR_RTSC); + } else if (sci_getreg(port, SCSPTR)->size) { + u16 ctrl = serial_port_in(port, SCSPTR); + + /* Active low */ + if (state) + ctrl &= ~SCSPTR_RTSDT; + else + ctrl |= SCSPTR_RTSDT; + serial_port_out(port, SCSPTR, ctrl); + } +} + +static bool sci_get_cts(struct uart_port *port) +{ + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { + /* Active low */ + return !(serial_port_in(port, SCPDR) & SCPDR_CTSD); + } else if (sci_getreg(port, SCSPTR)->size) { + /* Active low */ + return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT); + } + + return true; +} + +/* + * Modem control is a bit of a mixed bag for SCI(F) ports. Generally + * CTS/RTS is supported in hardware by at least one port and controlled + * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently + * handled via the ->init_pins() op, which is a bit of a one-way street, + * lacking any ability to defer pin control -- this will later be + * converted over to the GPIO framework). + * + * Other modes (such as loopback) are supported generically on certain + * port types, but not others. For these it's sufficient to test for the + * existence of the support register and simply ignore the port type. + */ +static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + struct sci_port *s = to_sci_port(port); + + if (mctrl & TIOCM_LOOP) { + const struct plat_sci_reg *reg; + + /* + * Standard loopback mode for SCFCR ports. + */ + reg = sci_getreg(port, SCFCR); + if (reg->size) + serial_port_out(port, SCFCR, + serial_port_in(port, SCFCR) | + SCFCR_LOOP); + } + + mctrl_gpio_set(s->gpios, mctrl); + + if (!s->has_rtscts) + return; + + if (!(mctrl & TIOCM_RTS)) { + /* Disable Auto RTS */ + serial_port_out(port, SCFCR, + serial_port_in(port, SCFCR) & ~SCFCR_MCE); + + /* Clear RTS */ + sci_set_rts(port, 0); + } else if (s->autorts) { + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { + /* Enable RTS# pin function */ + serial_port_out(port, SCPCR, + serial_port_in(port, SCPCR) & ~SCPCR_RTSC); + } + + /* Enable Auto RTS */ + serial_port_out(port, SCFCR, + serial_port_in(port, SCFCR) | SCFCR_MCE); + } else { + /* Set RTS */ + sci_set_rts(port, 1); + } +} + +static unsigned int sci_get_mctrl(struct uart_port *port) +{ + struct sci_port *s = to_sci_port(port); + struct mctrl_gpios *gpios = s->gpios; + unsigned int mctrl = 0; + + mctrl_gpio_get(gpios, &mctrl); + + /* + * CTS/RTS is handled in hardware when supported, while nothing + * else is wired up. + */ + if (s->autorts) { + if (sci_get_cts(port)) + mctrl |= TIOCM_CTS; + } else if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) { + mctrl |= TIOCM_CTS; + } + if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR)) + mctrl |= TIOCM_DSR; + if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD)) + mctrl |= TIOCM_CAR; + + return mctrl; +} + +static void sci_enable_ms(struct uart_port *port) +{ + mctrl_gpio_enable_ms(to_sci_port(port)->gpios); +} + +static void sci_break_ctl(struct uart_port *port, int break_state) +{ + unsigned short scscr, scsptr; + unsigned long flags; + + /* check wheter the port has SCSPTR */ + if (!sci_getreg(port, SCSPTR)->size) { + /* + * Not supported by hardware. Most parts couple break and rx + * interrupts together, with break detection always enabled. + */ + return; + } + + spin_lock_irqsave(&port->lock, flags); + scsptr = serial_port_in(port, SCSPTR); + scscr = serial_port_in(port, SCSCR); + + if (break_state == -1) { + scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT; + scscr &= ~SCSCR_TE; + } else { + scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO; + scscr |= SCSCR_TE; + } + + serial_port_out(port, SCSPTR, scsptr); + serial_port_out(port, SCSCR, scscr); + spin_unlock_irqrestore(&port->lock, flags); +} + +static int sci_startup(struct uart_port *port) +{ + struct sci_port *s = to_sci_port(port); + int ret; + + dev_dbg(port->dev, "%s(%d)\n", __func__, port->line); + + sci_request_dma(port); + + ret = sci_request_irq(s); + if (unlikely(ret < 0)) { + sci_free_dma(port); + return ret; + } + + return 0; +} + +static void sci_shutdown(struct uart_port *port) +{ + struct sci_port *s = to_sci_port(port); + unsigned long flags; + u16 scr; + + dev_dbg(port->dev, "%s(%d)\n", __func__, port->line); + + s->autorts = false; + mctrl_gpio_disable_ms(to_sci_port(port)->gpios); + + spin_lock_irqsave(&port->lock, flags); + sci_stop_rx(port); + sci_stop_tx(port); + /* + * Stop RX and TX, disable related interrupts, keep clock source + * and HSCIF TOT bits + */ + scr = serial_port_in(port, SCSCR); + serial_port_out(port, SCSCR, scr & + (SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot)); + spin_unlock_irqrestore(&port->lock, flags); + +#ifdef CONFIG_SERIAL_SH_SCI_DMA + if (s->chan_rx_saved) { + dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__, + port->line); + hrtimer_cancel(&s->rx_timer); + } +#endif + + if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) + del_timer_sync(&s->rx_fifo_timer); + sci_free_irq(s); + sci_free_dma(port); +} + +static int sci_sck_calc(struct sci_port *s, unsigned int bps, + unsigned int *srr) +{ + unsigned long freq = s->clk_rates[SCI_SCK]; + int err, min_err = INT_MAX; + unsigned int sr; + + if (s->port.type != PORT_HSCIF) + freq *= 2; + + for_each_sr(sr, s) { + err = DIV_ROUND_CLOSEST(freq, sr) - bps; + if (abs(err) >= abs(min_err)) + continue; + + min_err = err; + *srr = sr - 1; + + if (!err) + break; + } + + dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err, + *srr + 1); + return min_err; +} + +static int sci_brg_calc(struct sci_port *s, unsigned int bps, + unsigned long freq, unsigned int *dlr, + unsigned int *srr) +{ + int err, min_err = INT_MAX; + unsigned int sr, dl; + + if (s->port.type != PORT_HSCIF) + freq *= 2; + + for_each_sr(sr, s) { + dl = DIV_ROUND_CLOSEST(freq, sr * bps); + dl = clamp(dl, 1U, 65535U); + + err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps; + if (abs(err) >= abs(min_err)) + continue; + + min_err = err; + *dlr = dl; + *srr = sr - 1; + + if (!err) + break; + } + + dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps, + min_err, *dlr, *srr + 1); + return min_err; +} + +/* calculate sample rate, BRR, and clock select */ +static int sci_scbrr_calc(struct sci_port *s, unsigned int bps, + unsigned int *brr, unsigned int *srr, + unsigned int *cks) +{ + unsigned long freq = s->clk_rates[SCI_FCK]; + unsigned int sr, br, prediv, scrate, c; + int err, min_err = INT_MAX; + + if (s->port.type != PORT_HSCIF) + freq *= 2; + + /* + * Find the combination of sample rate and clock select with the + * smallest deviation from the desired baud rate. + * Prefer high sample rates to maximise the receive margin. + * + * M: Receive margin (%) + * N: Ratio of bit rate to clock (N = sampling rate) + * D: Clock duty (D = 0 to 1.0) + * L: Frame length (L = 9 to 12) + * F: Absolute value of clock frequency deviation + * + * M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) - + * (|D - 0.5| / N * (1 + F))| + * NOTE: Usually, treat D for 0.5, F is 0 by this calculation. + */ + for_each_sr(sr, s) { + for (c = 0; c <= 3; c++) { + /* integerized formulas from HSCIF documentation */ + prediv = sr * (1 << (2 * c + 1)); + + /* + * We need to calculate: + * + * br = freq / (prediv * bps) clamped to [1..256] + * err = freq / (br * prediv) - bps + * + * Watch out for overflow when calculating the desired + * sampling clock rate! + */ + if (bps > UINT_MAX / prediv) + break; + + scrate = prediv * bps; + br = DIV_ROUND_CLOSEST(freq, scrate); + br = clamp(br, 1U, 256U); + + err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps; + if (abs(err) >= abs(min_err)) + continue; + + min_err = err; + *brr = br - 1; + *srr = sr - 1; + *cks = c; + + if (!err) + goto found; + } + } + +found: + dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps, + min_err, *brr, *srr + 1, *cks); + return min_err; +} + +static void sci_reset(struct uart_port *port) +{ + const struct plat_sci_reg *reg; + unsigned int status; + struct sci_port *s = to_sci_port(port); + + serial_port_out(port, SCSCR, s->hscif_tot); /* TE=0, RE=0, CKE1=0 */ + + reg = sci_getreg(port, SCFCR); + if (reg->size) + serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST); + + sci_clear_SCxSR(port, + SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) & + SCxSR_BREAK_CLEAR(port)); + if (sci_getreg(port, SCLSR)->size) { + status = serial_port_in(port, SCLSR); + status &= ~(SCLSR_TO | SCLSR_ORER); + serial_port_out(port, SCLSR, status); + } + + if (s->rx_trigger > 1) { + if (s->rx_fifo_timeout) { + scif_set_rtrg(port, 1); + timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0); + } else { + if (port->type == PORT_SCIFA || + port->type == PORT_SCIFB) + scif_set_rtrg(port, 1); + else + scif_set_rtrg(port, s->rx_trigger); + } + } +} + +static void sci_set_termios(struct uart_port *port, struct ktermios *termios, + struct ktermios *old) +{ + unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits; + unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0; + unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0; + struct sci_port *s = to_sci_port(port); + const struct plat_sci_reg *reg; + int min_err = INT_MAX, err; + unsigned long max_freq = 0; + int best_clk = -1; + unsigned long flags; + + if ((termios->c_cflag & CSIZE) == CS7) { + smr_val |= SCSMR_CHR; + } else { + termios->c_cflag &= ~CSIZE; + termios->c_cflag |= CS8; + } + if (termios->c_cflag & PARENB) + smr_val |= SCSMR_PE; + if (termios->c_cflag & PARODD) + smr_val |= SCSMR_PE | SCSMR_ODD; + if (termios->c_cflag & CSTOPB) + smr_val |= SCSMR_STOP; + + /* + * earlyprintk comes here early on with port->uartclk set to zero. + * the clock framework is not up and running at this point so here + * we assume that 115200 is the maximum baud rate. please note that + * the baud rate is not programmed during earlyprintk - it is assumed + * that the previous boot loader has enabled required clocks and + * setup the baud rate generator hardware for us already. + */ + if (!port->uartclk) { + baud = uart_get_baud_rate(port, termios, old, 0, 115200); + goto done; + } + + for (i = 0; i < SCI_NUM_CLKS; i++) + max_freq = max(max_freq, s->clk_rates[i]); + + baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s)); + if (!baud) + goto done; + + /* + * There can be multiple sources for the sampling clock. Find the one + * that gives us the smallest deviation from the desired baud rate. + */ + + /* Optional Undivided External Clock */ + if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA && + port->type != PORT_SCIFB) { + err = sci_sck_calc(s, baud, &srr1); + if (abs(err) < abs(min_err)) { + best_clk = SCI_SCK; + scr_val = SCSCR_CKE1; + sccks = SCCKS_CKS; + min_err = err; + srr = srr1; + if (!err) + goto done; + } + } + + /* Optional BRG Frequency Divided External Clock */ + if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) { + err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1, + &srr1); + if (abs(err) < abs(min_err)) { + best_clk = SCI_SCIF_CLK; + scr_val = SCSCR_CKE1; + sccks = 0; + min_err = err; + dl = dl1; + srr = srr1; + if (!err) + goto done; + } + } + + /* Optional BRG Frequency Divided Internal Clock */ + if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) { + err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1, + &srr1); + if (abs(err) < abs(min_err)) { + best_clk = SCI_BRG_INT; + scr_val = SCSCR_CKE1; + sccks = SCCKS_XIN; + min_err = err; + dl = dl1; + srr = srr1; + if (!min_err) + goto done; + } + } + + /* Divided Functional Clock using standard Bit Rate Register */ + err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1); + if (abs(err) < abs(min_err)) { + best_clk = SCI_FCK; + scr_val = 0; + min_err = err; + brr = brr1; + srr = srr1; + cks = cks1; + } + +done: + if (best_clk >= 0) + dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n", + s->clks[best_clk], baud, min_err); + + sci_port_enable(s); + + /* + * Program the optional External Baud Rate Generator (BRG) first. + * It controls the mux to select (H)SCK or frequency divided clock. + */ + if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) { + serial_port_out(port, SCDL, dl); + serial_port_out(port, SCCKS, sccks); + } + + spin_lock_irqsave(&port->lock, flags); + + sci_reset(port); + + uart_update_timeout(port, termios->c_cflag, baud); + + /* byte size and parity */ + switch (termios->c_cflag & CSIZE) { + case CS5: + bits = 7; + break; + case CS6: + bits = 8; + break; + case CS7: + bits = 9; + break; + default: + bits = 10; + break; + } + + if (termios->c_cflag & CSTOPB) + bits++; + if (termios->c_cflag & PARENB) + bits++; + + if (best_clk >= 0) { + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) + switch (srr + 1) { + case 5: smr_val |= SCSMR_SRC_5; break; + case 7: smr_val |= SCSMR_SRC_7; break; + case 11: smr_val |= SCSMR_SRC_11; break; + case 13: smr_val |= SCSMR_SRC_13; break; + case 16: smr_val |= SCSMR_SRC_16; break; + case 17: smr_val |= SCSMR_SRC_17; break; + case 19: smr_val |= SCSMR_SRC_19; break; + case 27: smr_val |= SCSMR_SRC_27; break; + } + smr_val |= cks; + serial_port_out(port, SCSCR, scr_val | s->hscif_tot); + serial_port_out(port, SCSMR, smr_val); + serial_port_out(port, SCBRR, brr); + if (sci_getreg(port, HSSRR)->size) { + unsigned int hssrr = srr | HSCIF_SRE; + /* Calculate deviation from intended rate at the + * center of the last stop bit in sampling clocks. + */ + int last_stop = bits * 2 - 1; + int deviation = DIV_ROUND_CLOSEST(min_err * last_stop * + (int)(srr + 1), + 2 * (int)baud); + + if (abs(deviation) >= 2) { + /* At least two sampling clocks off at the + * last stop bit; we can increase the error + * margin by shifting the sampling point. + */ + int shift = clamp(deviation / 2, -8, 7); + + hssrr |= (shift << HSCIF_SRHP_SHIFT) & + HSCIF_SRHP_MASK; + hssrr |= HSCIF_SRDE; + } + serial_port_out(port, HSSRR, hssrr); + } + + /* Wait one bit interval */ + udelay((1000000 + (baud - 1)) / baud); + } else { + /* Don't touch the bit rate configuration */ + scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0); + smr_val |= serial_port_in(port, SCSMR) & + (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS); + serial_port_out(port, SCSCR, scr_val | s->hscif_tot); + serial_port_out(port, SCSMR, smr_val); + } + + sci_init_pins(port, termios->c_cflag); + + port->status &= ~UPSTAT_AUTOCTS; + s->autorts = false; + reg = sci_getreg(port, SCFCR); + if (reg->size) { + unsigned short ctrl = serial_port_in(port, SCFCR); + + if ((port->flags & UPF_HARD_FLOW) && + (termios->c_cflag & CRTSCTS)) { + /* There is no CTS interrupt to restart the hardware */ + port->status |= UPSTAT_AUTOCTS; + /* MCE is enabled when RTS is raised */ + s->autorts = true; + } + + /* + * As we've done a sci_reset() above, ensure we don't + * interfere with the FIFOs while toggling MCE. As the + * reset values could still be set, simply mask them out. + */ + ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST); + + serial_port_out(port, SCFCR, ctrl); + } + if (port->flags & UPF_HARD_FLOW) { + /* Refresh (Auto) RTS */ + sci_set_mctrl(port, port->mctrl); + } + + scr_val |= SCSCR_RE | SCSCR_TE | + (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)); + serial_port_out(port, SCSCR, scr_val | s->hscif_tot); + if ((srr + 1 == 5) && + (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) { + /* + * In asynchronous mode, when the sampling rate is 1/5, first + * received data may become invalid on some SCIFA and SCIFB. + * To avoid this problem wait more than 1 serial data time (1 + * bit time x serial data number) after setting SCSCR.RE = 1. + */ + udelay(DIV_ROUND_UP(10 * 1000000, baud)); + } + + /* + * Calculate delay for 2 DMA buffers (4 FIFO). + * See serial_core.c::uart_update_timeout(). + * With 10 bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above + * function calculates 1 jiffie for the data plus 5 jiffies for the + * "slop(e)." Then below we calculate 5 jiffies (20ms) for 2 DMA + * buffers (4 FIFO sizes), but when performing a faster transfer, the + * value obtained by this formula is too small. Therefore, if the value + * is smaller than 20ms, use 20ms as the timeout value for DMA. + */ + s->rx_frame = (10000 * bits) / (baud / 100); +#ifdef CONFIG_SERIAL_SH_SCI_DMA + s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame; + if (s->rx_timeout < 20) + s->rx_timeout = 20; +#endif + + if ((termios->c_cflag & CREAD) != 0) + sci_start_rx(port); + + spin_unlock_irqrestore(&port->lock, flags); + + sci_port_disable(s); + + if (UART_ENABLE_MS(port, termios->c_cflag)) + sci_enable_ms(port); +} + +static void sci_pm(struct uart_port *port, unsigned int state, + unsigned int oldstate) +{ + struct sci_port *sci_port = to_sci_port(port); + + switch (state) { + case UART_PM_STATE_OFF: + sci_port_disable(sci_port); + break; + default: + sci_port_enable(sci_port); + break; + } +} + +static const char *sci_type(struct uart_port *port) +{ + switch (port->type) { + case PORT_IRDA: + return "irda"; + case PORT_SCI: + return "sci"; + case PORT_SCIF: + return "scif"; + case PORT_SCIFA: + return "scifa"; + case PORT_SCIFB: + return "scifb"; + case PORT_HSCIF: + return "hscif"; + } + + return NULL; +} + +static int sci_remap_port(struct uart_port *port) +{ + struct sci_port *sport = to_sci_port(port); + + /* + * Nothing to do if there's already an established membase. + */ + if (port->membase) + return 0; + + if (port->dev->of_node || (port->flags & UPF_IOREMAP)) { + port->membase = ioremap(port->mapbase, sport->reg_size); + if (unlikely(!port->membase)) { + dev_err(port->dev, "can't remap port#%d\n", port->line); + return -ENXIO; + } + } else { + /* + * For the simple (and majority of) cases where we don't + * need to do any remapping, just cast the cookie + * directly. + */ + port->membase = (void __iomem *)(uintptr_t)port->mapbase; + } + + return 0; +} + +static void sci_release_port(struct uart_port *port) +{ + struct sci_port *sport = to_sci_port(port); + + if (port->dev->of_node || (port->flags & UPF_IOREMAP)) { + iounmap(port->membase); + port->membase = NULL; + } + + release_mem_region(port->mapbase, sport->reg_size); +} + +static int sci_request_port(struct uart_port *port) +{ + struct resource *res; + struct sci_port *sport = to_sci_port(port); + int ret; + + res = request_mem_region(port->mapbase, sport->reg_size, + dev_name(port->dev)); + if (unlikely(res == NULL)) { + dev_err(port->dev, "request_mem_region failed."); + return -EBUSY; + } + + ret = sci_remap_port(port); + if (unlikely(ret != 0)) { + release_resource(res); + return ret; + } + + return 0; +} + +static void sci_config_port(struct uart_port *port, int flags) +{ + if (flags & UART_CONFIG_TYPE) { + struct sci_port *sport = to_sci_port(port); + + port->type = sport->cfg->type; + sci_request_port(port); + } +} + +static int sci_verify_port(struct uart_port *port, struct serial_struct *ser) +{ + if (ser->baud_base < 2400) + /* No paper tape reader for Mitch.. */ + return -EINVAL; + + return 0; +} + +static const struct uart_ops sci_uart_ops = { + .tx_empty = sci_tx_empty, + .set_mctrl = sci_set_mctrl, + .get_mctrl = sci_get_mctrl, + .start_tx = sci_start_tx, + .stop_tx = sci_stop_tx, + .stop_rx = sci_stop_rx, + .enable_ms = sci_enable_ms, + .break_ctl = sci_break_ctl, + .startup = sci_startup, + .shutdown = sci_shutdown, + .flush_buffer = sci_flush_buffer, + .set_termios = sci_set_termios, + .pm = sci_pm, + .type = sci_type, + .release_port = sci_release_port, + .request_port = sci_request_port, + .config_port = sci_config_port, + .verify_port = sci_verify_port, +#ifdef CONFIG_CONSOLE_POLL + .poll_get_char = sci_poll_get_char, + .poll_put_char = sci_poll_put_char, +#endif +}; + +static int sci_init_clocks(struct sci_port *sci_port, struct device *dev) +{ + const char *clk_names[] = { + [SCI_FCK] = "fck", + [SCI_SCK] = "sck", + [SCI_BRG_INT] = "brg_int", + [SCI_SCIF_CLK] = "scif_clk", + }; + struct clk *clk; + unsigned int i; + + if (sci_port->cfg->type == PORT_HSCIF) + clk_names[SCI_SCK] = "hsck"; + + for (i = 0; i < SCI_NUM_CLKS; i++) { + clk = devm_clk_get(dev, clk_names[i]); + if (PTR_ERR(clk) == -EPROBE_DEFER) + return -EPROBE_DEFER; + + if (IS_ERR(clk) && i == SCI_FCK) { + /* + * "fck" used to be called "sci_ick", and we need to + * maintain DT backward compatibility. + */ + clk = devm_clk_get(dev, "sci_ick"); + if (PTR_ERR(clk) == -EPROBE_DEFER) + return -EPROBE_DEFER; + + if (!IS_ERR(clk)) + goto found; + + /* + * Not all SH platforms declare a clock lookup entry + * for SCI devices, in which case we need to get the + * global "peripheral_clk" clock. + */ + clk = devm_clk_get(dev, "peripheral_clk"); + if (!IS_ERR(clk)) + goto found; + + dev_err(dev, "failed to get %s (%ld)\n", clk_names[i], + PTR_ERR(clk)); + return PTR_ERR(clk); + } + +found: + if (IS_ERR(clk)) + dev_dbg(dev, "failed to get %s (%ld)\n", clk_names[i], + PTR_ERR(clk)); + else + dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i], + clk, clk_get_rate(clk)); + sci_port->clks[i] = IS_ERR(clk) ? NULL : clk; + } + return 0; +} + +static const struct sci_port_params * +sci_probe_regmap(const struct plat_sci_port *cfg) +{ + unsigned int regtype; + + if (cfg->regtype != SCIx_PROBE_REGTYPE) + return &sci_port_params[cfg->regtype]; + + switch (cfg->type) { + case PORT_SCI: + regtype = SCIx_SCI_REGTYPE; + break; + case PORT_IRDA: + regtype = SCIx_IRDA_REGTYPE; + break; + case PORT_SCIFA: + regtype = SCIx_SCIFA_REGTYPE; + break; + case PORT_SCIFB: + regtype = SCIx_SCIFB_REGTYPE; + break; + case PORT_SCIF: + /* + * The SH-4 is a bit of a misnomer here, although that's + * where this particular port layout originated. This + * configuration (or some slight variation thereof) + * remains the dominant model for all SCIFs. + */ + regtype = SCIx_SH4_SCIF_REGTYPE; + break; + case PORT_HSCIF: + regtype = SCIx_HSCIF_REGTYPE; + break; + default: + pr_err("Can't probe register map for given port\n"); + return NULL; + } + + return &sci_port_params[regtype]; +} + +static int sci_init_single(struct platform_device *dev, + struct sci_port *sci_port, unsigned int index, + const struct plat_sci_port *p, bool early) +{ + struct uart_port *port = &sci_port->port; + const struct resource *res; + unsigned int i; + int ret; + + sci_port->cfg = p; + + port->ops = &sci_uart_ops; + port->iotype = UPIO_MEM; + port->line = index; + port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SH_SCI_CONSOLE); + + res = platform_get_resource(dev, IORESOURCE_MEM, 0); + if (res == NULL) + return -ENOMEM; + + port->mapbase = res->start; + sci_port->reg_size = resource_size(res); + + for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) { + if (i) + sci_port->irqs[i] = platform_get_irq_optional(dev, i); + else + sci_port->irqs[i] = platform_get_irq(dev, i); + } + + /* + * The fourth interrupt on SCI port is transmit end interrupt, so + * shuffle the interrupts. + */ + if (p->type == PORT_SCI) + swap(sci_port->irqs[SCIx_BRI_IRQ], sci_port->irqs[SCIx_TEI_IRQ]); + + /* The SCI generates several interrupts. They can be muxed together or + * connected to different interrupt lines. In the muxed case only one + * interrupt resource is specified as there is only one interrupt ID. + * In the non-muxed case, up to 6 interrupt signals might be generated + * from the SCI, however those signals might have their own individual + * interrupt ID numbers, or muxed together with another interrupt. + */ + if (sci_port->irqs[0] < 0) + return -ENXIO; + + if (sci_port->irqs[1] < 0) + for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++) + sci_port->irqs[i] = sci_port->irqs[0]; + + sci_port->params = sci_probe_regmap(p); + if (unlikely(sci_port->params == NULL)) + return -EINVAL; + + switch (p->type) { + case PORT_SCIFB: + sci_port->rx_trigger = 48; + break; + case PORT_HSCIF: + sci_port->rx_trigger = 64; + break; + case PORT_SCIFA: + sci_port->rx_trigger = 32; + break; + case PORT_SCIF: + if (p->regtype == SCIx_SH7705_SCIF_REGTYPE) + /* RX triggering not implemented for this IP */ + sci_port->rx_trigger = 1; + else + sci_port->rx_trigger = 8; + break; + default: + sci_port->rx_trigger = 1; + break; + } + + sci_port->rx_fifo_timeout = 0; + sci_port->hscif_tot = 0; + + /* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't + * match the SoC datasheet, this should be investigated. Let platform + * data override the sampling rate for now. + */ + sci_port->sampling_rate_mask = p->sampling_rate + ? SCI_SR(p->sampling_rate) + : sci_port->params->sampling_rate_mask; + + if (!early) { + ret = sci_init_clocks(sci_port, &dev->dev); + if (ret < 0) + return ret; + + port->dev = &dev->dev; + + pm_runtime_enable(&dev->dev); + } + + port->type = p->type; + port->flags = UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags; + port->fifosize = sci_port->params->fifosize; + + if (port->type == PORT_SCI && !dev->dev.of_node) { + if (sci_port->reg_size >= 0x20) + port->regshift = 2; + else + port->regshift = 1; + } + + /* + * The UART port needs an IRQ value, so we peg this to the RX IRQ + * for the multi-IRQ ports, which is where we are primarily + * concerned with the shutdown path synchronization. + * + * For the muxed case there's nothing more to do. + */ + port->irq = sci_port->irqs[SCIx_RXI_IRQ]; + port->irqflags = 0; + + port->serial_in = sci_serial_in; + port->serial_out = sci_serial_out; + + return 0; +} + +static void sci_cleanup_single(struct sci_port *port) +{ + pm_runtime_disable(port->port.dev); +} + +#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \ + defined(CONFIG_SERIAL_SH_SCI_EARLYCON) +static void serial_console_putchar(struct uart_port *port, int ch) +{ + sci_poll_put_char(port, ch); +} + +/* + * Print a string to the serial port trying not to disturb + * any possible real use of the port... + */ +static void serial_console_write(struct console *co, const char *s, + unsigned count) +{ + struct sci_port *sci_port = &sci_ports[co->index]; + struct uart_port *port = &sci_port->port; + unsigned short bits, ctrl, ctrl_temp; + unsigned long flags; + int locked = 1; + + if (port->sysrq) + locked = 0; + else if (oops_in_progress) + locked = spin_trylock_irqsave(&port->lock, flags); + else + spin_lock_irqsave(&port->lock, flags); + + /* first save SCSCR then disable interrupts, keep clock source */ + ctrl = serial_port_in(port, SCSCR); + ctrl_temp = SCSCR_RE | SCSCR_TE | + (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) | + (ctrl & (SCSCR_CKE1 | SCSCR_CKE0)); + serial_port_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot); + + uart_console_write(port, s, count, serial_console_putchar); + + /* wait until fifo is empty and last bit has been transmitted */ + bits = SCxSR_TDxE(port) | SCxSR_TEND(port); + while ((serial_port_in(port, SCxSR) & bits) != bits) + cpu_relax(); + + /* restore the SCSCR */ + serial_port_out(port, SCSCR, ctrl); + + if (locked) + spin_unlock_irqrestore(&port->lock, flags); +} + +static int serial_console_setup(struct console *co, char *options) +{ + struct sci_port *sci_port; + struct uart_port *port; + int baud = 115200; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + int ret; + + /* + * Refuse to handle any bogus ports. + */ + if (co->index < 0 || co->index >= SCI_NPORTS) + return -ENODEV; + + sci_port = &sci_ports[co->index]; + port = &sci_port->port; + + /* + * Refuse to handle uninitialized ports. + */ + if (!port->ops) + return -ENODEV; + + ret = sci_remap_port(port); + if (unlikely(ret != 0)) + return ret; + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + + return uart_set_options(port, co, baud, parity, bits, flow); +} + +static struct console serial_console = { + .name = "ttySC", + .device = uart_console_device, + .write = serial_console_write, + .setup = serial_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &sci_uart_driver, +}; + +#ifdef CONFIG_SUPERH +static struct console early_serial_console = { + .name = "early_ttySC", + .write = serial_console_write, + .flags = CON_PRINTBUFFER, + .index = -1, +}; + +static char early_serial_buf[32]; + +static int sci_probe_earlyprintk(struct platform_device *pdev) +{ + const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev); + + if (early_serial_console.data) + return -EEXIST; + + early_serial_console.index = pdev->id; + + sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true); + + serial_console_setup(&early_serial_console, early_serial_buf); + + if (!strstr(early_serial_buf, "keep")) + early_serial_console.flags |= CON_BOOT; + + register_console(&early_serial_console); + return 0; +} +#endif + +#define SCI_CONSOLE (&serial_console) + +#else +static inline int sci_probe_earlyprintk(struct platform_device *pdev) +{ + return -EINVAL; +} + +#define SCI_CONSOLE NULL + +#endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */ + +static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized"; + +static DEFINE_MUTEX(sci_uart_registration_lock); +static struct uart_driver sci_uart_driver = { + .owner = THIS_MODULE, + .driver_name = "sci", + .dev_name = "ttySC", + .major = SCI_MAJOR, + .minor = SCI_MINOR_START, + .nr = SCI_NPORTS, + .cons = SCI_CONSOLE, +}; + +static int sci_remove(struct platform_device *dev) +{ + struct sci_port *port = platform_get_drvdata(dev); + unsigned int type = port->port.type; /* uart_remove_... clears it */ + + sci_ports_in_use &= ~BIT(port->port.line); + uart_remove_one_port(&sci_uart_driver, &port->port); + + sci_cleanup_single(port); + + if (port->port.fifosize > 1) + device_remove_file(&dev->dev, &dev_attr_rx_fifo_trigger); + if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF) + device_remove_file(&dev->dev, &dev_attr_rx_fifo_timeout); + + return 0; +} + + +#define SCI_OF_DATA(type, regtype) (void *)((type) << 16 | (regtype)) +#define SCI_OF_TYPE(data) ((unsigned long)(data) >> 16) +#define SCI_OF_REGTYPE(data) ((unsigned long)(data) & 0xffff) + +static const struct of_device_id of_sci_match[] = { + /* SoC-specific types */ + { + .compatible = "renesas,scif-r7s72100", + .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE), + }, + { + .compatible = "renesas,scif-r7s9210", + .data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE), + }, + /* Family-specific types */ + { + .compatible = "renesas,rcar-gen1-scif", + .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE), + }, { + .compatible = "renesas,rcar-gen2-scif", + .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE), + }, { + .compatible = "renesas,rcar-gen3-scif", + .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE), + }, + /* Generic types */ + { + .compatible = "renesas,scif", + .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE), + }, { + .compatible = "renesas,scifa", + .data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE), + }, { + .compatible = "renesas,scifb", + .data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE), + }, { + .compatible = "renesas,hscif", + .data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE), + }, { + .compatible = "renesas,sci", + .data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE), + }, { + /* Terminator */ + }, +}; +MODULE_DEVICE_TABLE(of, of_sci_match); + +static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev, + unsigned int *dev_id) +{ + struct device_node *np = pdev->dev.of_node; + struct plat_sci_port *p; + struct sci_port *sp; + const void *data; + int id; + + if (!IS_ENABLED(CONFIG_OF) || !np) + return NULL; + + data = of_device_get_match_data(&pdev->dev); + + p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL); + if (!p) + return NULL; + + /* Get the line number from the aliases node. */ + id = of_alias_get_id(np, "serial"); + if (id < 0 && ~sci_ports_in_use) + id = ffz(sci_ports_in_use); + if (id < 0) { + dev_err(&pdev->dev, "failed to get alias id (%d)\n", id); + return NULL; + } + if (id >= ARRAY_SIZE(sci_ports)) { + dev_err(&pdev->dev, "serial%d out of range\n", id); + return NULL; + } + + sp = &sci_ports[id]; + *dev_id = id; + + p->type = SCI_OF_TYPE(data); + p->regtype = SCI_OF_REGTYPE(data); + + sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts"); + + return p; +} + +static int sci_probe_single(struct platform_device *dev, + unsigned int index, + struct plat_sci_port *p, + struct sci_port *sciport) +{ + int ret; + + /* Sanity check */ + if (unlikely(index >= SCI_NPORTS)) { + dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n", + index+1, SCI_NPORTS); + dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n"); + return -EINVAL; + } + BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8); + if (sci_ports_in_use & BIT(index)) + return -EBUSY; + + mutex_lock(&sci_uart_registration_lock); + if (!sci_uart_driver.state) { + ret = uart_register_driver(&sci_uart_driver); + if (ret) { + mutex_unlock(&sci_uart_registration_lock); + return ret; + } + } + mutex_unlock(&sci_uart_registration_lock); + + ret = sci_init_single(dev, sciport, index, p, false); + if (ret) + return ret; + + sciport->gpios = mctrl_gpio_init(&sciport->port, 0); + if (IS_ERR(sciport->gpios)) + return PTR_ERR(sciport->gpios); + + if (sciport->has_rtscts) { + if (mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_CTS) || + mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_RTS)) { + dev_err(&dev->dev, "Conflicting RTS/CTS config\n"); + return -EINVAL; + } + sciport->port.flags |= UPF_HARD_FLOW; + } + + ret = uart_add_one_port(&sci_uart_driver, &sciport->port); + if (ret) { + sci_cleanup_single(sciport); + return ret; + } + + return 0; +} + +static int sci_probe(struct platform_device *dev) +{ + struct plat_sci_port *p; + struct sci_port *sp; + unsigned int dev_id; + int ret; + + /* + * If we've come here via earlyprintk initialization, head off to + * the special early probe. We don't have sufficient device state + * to make it beyond this yet. + */ +#ifdef CONFIG_SUPERH + if (is_sh_early_platform_device(dev)) + return sci_probe_earlyprintk(dev); +#endif + + if (dev->dev.of_node) { + p = sci_parse_dt(dev, &dev_id); + if (p == NULL) + return -EINVAL; + } else { + p = dev->dev.platform_data; + if (p == NULL) { + dev_err(&dev->dev, "no platform data supplied\n"); + return -EINVAL; + } + + dev_id = dev->id; + } + + sp = &sci_ports[dev_id]; + platform_set_drvdata(dev, sp); + + ret = sci_probe_single(dev, dev_id, p, sp); + if (ret) + return ret; + + if (sp->port.fifosize > 1) { + ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_trigger); + if (ret) + return ret; + } + if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB || + sp->port.type == PORT_HSCIF) { + ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_timeout); + if (ret) { + if (sp->port.fifosize > 1) { + device_remove_file(&dev->dev, + &dev_attr_rx_fifo_trigger); + } + return ret; + } + } + +#ifdef CONFIG_SH_STANDARD_BIOS + sh_bios_gdb_detach(); +#endif + + sci_ports_in_use |= BIT(dev_id); + return 0; +} + +static __maybe_unused int sci_suspend(struct device *dev) +{ + struct sci_port *sport = dev_get_drvdata(dev); + + if (sport) + uart_suspend_port(&sci_uart_driver, &sport->port); + + return 0; +} + +static __maybe_unused int sci_resume(struct device *dev) +{ + struct sci_port *sport = dev_get_drvdata(dev); + + if (sport) + uart_resume_port(&sci_uart_driver, &sport->port); + + return 0; +} + +static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume); + +static struct platform_driver sci_driver = { + .probe = sci_probe, + .remove = sci_remove, + .driver = { + .name = "sh-sci", + .pm = &sci_dev_pm_ops, + .of_match_table = of_match_ptr(of_sci_match), + }, +}; + +static int __init sci_init(void) +{ + pr_info("%s\n", banner); + + return platform_driver_register(&sci_driver); +} + +static void __exit sci_exit(void) +{ + platform_driver_unregister(&sci_driver); + + if (sci_uart_driver.state) + uart_unregister_driver(&sci_uart_driver); +} + +#if defined(CONFIG_SUPERH) && defined(CONFIG_SERIAL_SH_SCI_CONSOLE) +sh_early_platform_init_buffer("earlyprintk", &sci_driver, + early_serial_buf, ARRAY_SIZE(early_serial_buf)); +#endif +#ifdef CONFIG_SERIAL_SH_SCI_EARLYCON +static struct plat_sci_port port_cfg __initdata; + +static int __init early_console_setup(struct earlycon_device *device, + int type) +{ + if (!device->port.membase) + return -ENODEV; + + device->port.serial_in = sci_serial_in; + device->port.serial_out = sci_serial_out; + device->port.type = type; + memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port)); + port_cfg.type = type; + sci_ports[0].cfg = &port_cfg; + sci_ports[0].params = sci_probe_regmap(&port_cfg); + port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR); + sci_serial_out(&sci_ports[0].port, SCSCR, + SCSCR_RE | SCSCR_TE | port_cfg.scscr); + + device->con->write = serial_console_write; + return 0; +} +static int __init sci_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + return early_console_setup(device, PORT_SCI); +} +static int __init scif_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + return early_console_setup(device, PORT_SCIF); +} +static int __init rzscifa_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE; + return early_console_setup(device, PORT_SCIF); +} +static int __init scifa_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + return early_console_setup(device, PORT_SCIFA); +} +static int __init scifb_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + return early_console_setup(device, PORT_SCIFB); +} +static int __init hscif_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + return early_console_setup(device, PORT_HSCIF); +} + +OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup); +OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup); +OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup); +OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup); +OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup); +OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup); +#endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */ + +module_init(sci_init); +module_exit(sci_exit); + +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:sh-sci"); +MODULE_AUTHOR("Paul Mundt"); +MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver"); |