diff options
Diffstat (limited to 'drivers/tty/serial/fsl_lpuart.c')
| -rw-r--r-- | drivers/tty/serial/fsl_lpuart.c | 2871 |
1 files changed, 2871 insertions, 0 deletions
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c new file mode 100644 index 000000000..227fb2d32 --- /dev/null +++ b/drivers/tty/serial/fsl_lpuart.c @@ -0,0 +1,2871 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Freescale lpuart serial port driver + * + * Copyright 2012-2014 Freescale Semiconductor, Inc. + */ + +#include <linux/clk.h> +#include <linux/console.h> +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> +#include <linux/dmapool.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/of_dma.h> +#include <linux/serial_core.h> +#include <linux/slab.h> +#include <linux/tty_flip.h> + +/* All registers are 8-bit width */ +#define UARTBDH 0x00 +#define UARTBDL 0x01 +#define UARTCR1 0x02 +#define UARTCR2 0x03 +#define UARTSR1 0x04 +#define UARTCR3 0x06 +#define UARTDR 0x07 +#define UARTCR4 0x0a +#define UARTCR5 0x0b +#define UARTMODEM 0x0d +#define UARTPFIFO 0x10 +#define UARTCFIFO 0x11 +#define UARTSFIFO 0x12 +#define UARTTWFIFO 0x13 +#define UARTTCFIFO 0x14 +#define UARTRWFIFO 0x15 + +#define UARTBDH_LBKDIE 0x80 +#define UARTBDH_RXEDGIE 0x40 +#define UARTBDH_SBR_MASK 0x1f + +#define UARTCR1_LOOPS 0x80 +#define UARTCR1_RSRC 0x20 +#define UARTCR1_M 0x10 +#define UARTCR1_WAKE 0x08 +#define UARTCR1_ILT 0x04 +#define UARTCR1_PE 0x02 +#define UARTCR1_PT 0x01 + +#define UARTCR2_TIE 0x80 +#define UARTCR2_TCIE 0x40 +#define UARTCR2_RIE 0x20 +#define UARTCR2_ILIE 0x10 +#define UARTCR2_TE 0x08 +#define UARTCR2_RE 0x04 +#define UARTCR2_RWU 0x02 +#define UARTCR2_SBK 0x01 + +#define UARTSR1_TDRE 0x80 +#define UARTSR1_TC 0x40 +#define UARTSR1_RDRF 0x20 +#define UARTSR1_IDLE 0x10 +#define UARTSR1_OR 0x08 +#define UARTSR1_NF 0x04 +#define UARTSR1_FE 0x02 +#define UARTSR1_PE 0x01 + +#define UARTCR3_R8 0x80 +#define UARTCR3_T8 0x40 +#define UARTCR3_TXDIR 0x20 +#define UARTCR3_TXINV 0x10 +#define UARTCR3_ORIE 0x08 +#define UARTCR3_NEIE 0x04 +#define UARTCR3_FEIE 0x02 +#define UARTCR3_PEIE 0x01 + +#define UARTCR4_MAEN1 0x80 +#define UARTCR4_MAEN2 0x40 +#define UARTCR4_M10 0x20 +#define UARTCR4_BRFA_MASK 0x1f +#define UARTCR4_BRFA_OFF 0 + +#define UARTCR5_TDMAS 0x80 +#define UARTCR5_RDMAS 0x20 + +#define UARTMODEM_RXRTSE 0x08 +#define UARTMODEM_TXRTSPOL 0x04 +#define UARTMODEM_TXRTSE 0x02 +#define UARTMODEM_TXCTSE 0x01 + +#define UARTPFIFO_TXFE 0x80 +#define UARTPFIFO_FIFOSIZE_MASK 0x7 +#define UARTPFIFO_TXSIZE_OFF 4 +#define UARTPFIFO_RXFE 0x08 +#define UARTPFIFO_RXSIZE_OFF 0 + +#define UARTCFIFO_TXFLUSH 0x80 +#define UARTCFIFO_RXFLUSH 0x40 +#define UARTCFIFO_RXOFE 0x04 +#define UARTCFIFO_TXOFE 0x02 +#define UARTCFIFO_RXUFE 0x01 + +#define UARTSFIFO_TXEMPT 0x80 +#define UARTSFIFO_RXEMPT 0x40 +#define UARTSFIFO_RXOF 0x04 +#define UARTSFIFO_TXOF 0x02 +#define UARTSFIFO_RXUF 0x01 + +/* 32-bit register definition */ +#define UARTBAUD 0x00 +#define UARTSTAT 0x04 +#define UARTCTRL 0x08 +#define UARTDATA 0x0C +#define UARTMATCH 0x10 +#define UARTMODIR 0x14 +#define UARTFIFO 0x18 +#define UARTWATER 0x1c + +#define UARTBAUD_MAEN1 0x80000000 +#define UARTBAUD_MAEN2 0x40000000 +#define UARTBAUD_M10 0x20000000 +#define UARTBAUD_TDMAE 0x00800000 +#define UARTBAUD_RDMAE 0x00200000 +#define UARTBAUD_MATCFG 0x00400000 +#define UARTBAUD_BOTHEDGE 0x00020000 +#define UARTBAUD_RESYNCDIS 0x00010000 +#define UARTBAUD_LBKDIE 0x00008000 +#define UARTBAUD_RXEDGIE 0x00004000 +#define UARTBAUD_SBNS 0x00002000 +#define UARTBAUD_SBR 0x00000000 +#define UARTBAUD_SBR_MASK 0x1fff +#define UARTBAUD_OSR_MASK 0x1f +#define UARTBAUD_OSR_SHIFT 24 + +#define UARTSTAT_LBKDIF 0x80000000 +#define UARTSTAT_RXEDGIF 0x40000000 +#define UARTSTAT_MSBF 0x20000000 +#define UARTSTAT_RXINV 0x10000000 +#define UARTSTAT_RWUID 0x08000000 +#define UARTSTAT_BRK13 0x04000000 +#define UARTSTAT_LBKDE 0x02000000 +#define UARTSTAT_RAF 0x01000000 +#define UARTSTAT_TDRE 0x00800000 +#define UARTSTAT_TC 0x00400000 +#define UARTSTAT_RDRF 0x00200000 +#define UARTSTAT_IDLE 0x00100000 +#define UARTSTAT_OR 0x00080000 +#define UARTSTAT_NF 0x00040000 +#define UARTSTAT_FE 0x00020000 +#define UARTSTAT_PE 0x00010000 +#define UARTSTAT_MA1F 0x00008000 +#define UARTSTAT_M21F 0x00004000 + +#define UARTCTRL_R8T9 0x80000000 +#define UARTCTRL_R9T8 0x40000000 +#define UARTCTRL_TXDIR 0x20000000 +#define UARTCTRL_TXINV 0x10000000 +#define UARTCTRL_ORIE 0x08000000 +#define UARTCTRL_NEIE 0x04000000 +#define UARTCTRL_FEIE 0x02000000 +#define UARTCTRL_PEIE 0x01000000 +#define UARTCTRL_TIE 0x00800000 +#define UARTCTRL_TCIE 0x00400000 +#define UARTCTRL_RIE 0x00200000 +#define UARTCTRL_ILIE 0x00100000 +#define UARTCTRL_TE 0x00080000 +#define UARTCTRL_RE 0x00040000 +#define UARTCTRL_RWU 0x00020000 +#define UARTCTRL_SBK 0x00010000 +#define UARTCTRL_MA1IE 0x00008000 +#define UARTCTRL_MA2IE 0x00004000 +#define UARTCTRL_IDLECFG 0x00000100 +#define UARTCTRL_LOOPS 0x00000080 +#define UARTCTRL_DOZEEN 0x00000040 +#define UARTCTRL_RSRC 0x00000020 +#define UARTCTRL_M 0x00000010 +#define UARTCTRL_WAKE 0x00000008 +#define UARTCTRL_ILT 0x00000004 +#define UARTCTRL_PE 0x00000002 +#define UARTCTRL_PT 0x00000001 + +#define UARTDATA_NOISY 0x00008000 +#define UARTDATA_PARITYE 0x00004000 +#define UARTDATA_FRETSC 0x00002000 +#define UARTDATA_RXEMPT 0x00001000 +#define UARTDATA_IDLINE 0x00000800 +#define UARTDATA_MASK 0x3ff + +#define UARTMODIR_IREN 0x00020000 +#define UARTMODIR_TXCTSSRC 0x00000020 +#define UARTMODIR_TXCTSC 0x00000010 +#define UARTMODIR_RXRTSE 0x00000008 +#define UARTMODIR_TXRTSPOL 0x00000004 +#define UARTMODIR_TXRTSE 0x00000002 +#define UARTMODIR_TXCTSE 0x00000001 + +#define UARTFIFO_TXEMPT 0x00800000 +#define UARTFIFO_RXEMPT 0x00400000 +#define UARTFIFO_TXOF 0x00020000 +#define UARTFIFO_RXUF 0x00010000 +#define UARTFIFO_TXFLUSH 0x00008000 +#define UARTFIFO_RXFLUSH 0x00004000 +#define UARTFIFO_TXOFE 0x00000200 +#define UARTFIFO_RXUFE 0x00000100 +#define UARTFIFO_TXFE 0x00000080 +#define UARTFIFO_FIFOSIZE_MASK 0x7 +#define UARTFIFO_TXSIZE_OFF 4 +#define UARTFIFO_RXFE 0x00000008 +#define UARTFIFO_RXSIZE_OFF 0 +#define UARTFIFO_DEPTH(x) (0x1 << ((x) ? ((x) + 1) : 0)) + +#define UARTWATER_COUNT_MASK 0xff +#define UARTWATER_TXCNT_OFF 8 +#define UARTWATER_RXCNT_OFF 24 +#define UARTWATER_WATER_MASK 0xff +#define UARTWATER_TXWATER_OFF 0 +#define UARTWATER_RXWATER_OFF 16 + +/* Rx DMA timeout in ms, which is used to calculate Rx ring buffer size */ +#define DMA_RX_TIMEOUT (10) + +#define DRIVER_NAME "fsl-lpuart" +#define DEV_NAME "ttyLP" +#define UART_NR 6 + +/* IMX lpuart has four extra unused regs located at the beginning */ +#define IMX_REG_OFF 0x10 + +enum lpuart_type { + VF610_LPUART, + LS1021A_LPUART, + LS1028A_LPUART, + IMX7ULP_LPUART, + IMX8QXP_LPUART, +}; + +struct lpuart_port { + struct uart_port port; + enum lpuart_type devtype; + struct clk *ipg_clk; + struct clk *baud_clk; + unsigned int txfifo_size; + unsigned int rxfifo_size; + + bool lpuart_dma_tx_use; + bool lpuart_dma_rx_use; + struct dma_chan *dma_tx_chan; + struct dma_chan *dma_rx_chan; + struct dma_async_tx_descriptor *dma_tx_desc; + struct dma_async_tx_descriptor *dma_rx_desc; + dma_cookie_t dma_tx_cookie; + dma_cookie_t dma_rx_cookie; + unsigned int dma_tx_bytes; + unsigned int dma_rx_bytes; + bool dma_tx_in_progress; + unsigned int dma_rx_timeout; + struct timer_list lpuart_timer; + struct scatterlist rx_sgl, tx_sgl[2]; + struct circ_buf rx_ring; + int rx_dma_rng_buf_len; + unsigned int dma_tx_nents; + wait_queue_head_t dma_wait; +}; + +struct lpuart_soc_data { + enum lpuart_type devtype; + char iotype; + u8 reg_off; +}; + +static const struct lpuart_soc_data vf_data = { + .devtype = VF610_LPUART, + .iotype = UPIO_MEM, +}; + +static const struct lpuart_soc_data ls1021a_data = { + .devtype = LS1021A_LPUART, + .iotype = UPIO_MEM32BE, +}; + +static const struct lpuart_soc_data ls1028a_data = { + .devtype = LS1028A_LPUART, + .iotype = UPIO_MEM32, +}; + +static struct lpuart_soc_data imx7ulp_data = { + .devtype = IMX7ULP_LPUART, + .iotype = UPIO_MEM32, + .reg_off = IMX_REG_OFF, +}; + +static struct lpuart_soc_data imx8qxp_data = { + .devtype = IMX8QXP_LPUART, + .iotype = UPIO_MEM32, + .reg_off = IMX_REG_OFF, +}; + +static const struct of_device_id lpuart_dt_ids[] = { + { .compatible = "fsl,vf610-lpuart", .data = &vf_data, }, + { .compatible = "fsl,ls1021a-lpuart", .data = &ls1021a_data, }, + { .compatible = "fsl,ls1028a-lpuart", .data = &ls1028a_data, }, + { .compatible = "fsl,imx7ulp-lpuart", .data = &imx7ulp_data, }, + { .compatible = "fsl,imx8qxp-lpuart", .data = &imx8qxp_data, }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, lpuart_dt_ids); + +/* Forward declare this for the dma callbacks*/ +static void lpuart_dma_tx_complete(void *arg); + +static inline bool is_layerscape_lpuart(struct lpuart_port *sport) +{ + return (sport->devtype == LS1021A_LPUART || + sport->devtype == LS1028A_LPUART); +} + +static inline bool is_imx8qxp_lpuart(struct lpuart_port *sport) +{ + return sport->devtype == IMX8QXP_LPUART; +} + +static inline u32 lpuart32_read(struct uart_port *port, u32 off) +{ + switch (port->iotype) { + case UPIO_MEM32: + return readl(port->membase + off); + case UPIO_MEM32BE: + return ioread32be(port->membase + off); + default: + return 0; + } +} + +static inline void lpuart32_write(struct uart_port *port, u32 val, + u32 off) +{ + switch (port->iotype) { + case UPIO_MEM32: + writel(val, port->membase + off); + break; + case UPIO_MEM32BE: + iowrite32be(val, port->membase + off); + break; + } +} + +static int __lpuart_enable_clks(struct lpuart_port *sport, bool is_en) +{ + int ret = 0; + + if (is_en) { + ret = clk_prepare_enable(sport->ipg_clk); + if (ret) + return ret; + + ret = clk_prepare_enable(sport->baud_clk); + if (ret) { + clk_disable_unprepare(sport->ipg_clk); + return ret; + } + } else { + clk_disable_unprepare(sport->baud_clk); + clk_disable_unprepare(sport->ipg_clk); + } + + return 0; +} + +static unsigned int lpuart_get_baud_clk_rate(struct lpuart_port *sport) +{ + if (is_imx8qxp_lpuart(sport)) + return clk_get_rate(sport->baud_clk); + + return clk_get_rate(sport->ipg_clk); +} + +#define lpuart_enable_clks(x) __lpuart_enable_clks(x, true) +#define lpuart_disable_clks(x) __lpuart_enable_clks(x, false) + +static void lpuart_stop_tx(struct uart_port *port) +{ + unsigned char temp; + + temp = readb(port->membase + UARTCR2); + temp &= ~(UARTCR2_TIE | UARTCR2_TCIE); + writeb(temp, port->membase + UARTCR2); +} + +static void lpuart32_stop_tx(struct uart_port *port) +{ + unsigned long temp; + + temp = lpuart32_read(port, UARTCTRL); + temp &= ~(UARTCTRL_TIE | UARTCTRL_TCIE); + lpuart32_write(port, temp, UARTCTRL); +} + +static void lpuart_stop_rx(struct uart_port *port) +{ + unsigned char temp; + + temp = readb(port->membase + UARTCR2); + writeb(temp & ~UARTCR2_RE, port->membase + UARTCR2); +} + +static void lpuart32_stop_rx(struct uart_port *port) +{ + unsigned long temp; + + temp = lpuart32_read(port, UARTCTRL); + lpuart32_write(port, temp & ~UARTCTRL_RE, UARTCTRL); +} + +static void lpuart_dma_tx(struct lpuart_port *sport) +{ + struct circ_buf *xmit = &sport->port.state->xmit; + struct scatterlist *sgl = sport->tx_sgl; + struct device *dev = sport->port.dev; + struct dma_chan *chan = sport->dma_tx_chan; + int ret; + + if (sport->dma_tx_in_progress) + return; + + sport->dma_tx_bytes = uart_circ_chars_pending(xmit); + + if (xmit->tail < xmit->head || xmit->head == 0) { + sport->dma_tx_nents = 1; + sg_init_one(sgl, xmit->buf + xmit->tail, sport->dma_tx_bytes); + } else { + sport->dma_tx_nents = 2; + sg_init_table(sgl, 2); + sg_set_buf(sgl, xmit->buf + xmit->tail, + UART_XMIT_SIZE - xmit->tail); + sg_set_buf(sgl + 1, xmit->buf, xmit->head); + } + + ret = dma_map_sg(chan->device->dev, sgl, sport->dma_tx_nents, + DMA_TO_DEVICE); + if (!ret) { + dev_err(dev, "DMA mapping error for TX.\n"); + return; + } + + sport->dma_tx_desc = dmaengine_prep_slave_sg(chan, sgl, + ret, DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT); + if (!sport->dma_tx_desc) { + dma_unmap_sg(chan->device->dev, sgl, sport->dma_tx_nents, + DMA_TO_DEVICE); + dev_err(dev, "Cannot prepare TX slave DMA!\n"); + return; + } + + sport->dma_tx_desc->callback = lpuart_dma_tx_complete; + sport->dma_tx_desc->callback_param = sport; + sport->dma_tx_in_progress = true; + sport->dma_tx_cookie = dmaengine_submit(sport->dma_tx_desc); + dma_async_issue_pending(chan); +} + +static bool lpuart_stopped_or_empty(struct uart_port *port) +{ + return uart_circ_empty(&port->state->xmit) || uart_tx_stopped(port); +} + +static void lpuart_dma_tx_complete(void *arg) +{ + struct lpuart_port *sport = arg; + struct scatterlist *sgl = &sport->tx_sgl[0]; + struct circ_buf *xmit = &sport->port.state->xmit; + struct dma_chan *chan = sport->dma_tx_chan; + unsigned long flags; + + spin_lock_irqsave(&sport->port.lock, flags); + + dma_unmap_sg(chan->device->dev, sgl, sport->dma_tx_nents, + DMA_TO_DEVICE); + + xmit->tail = (xmit->tail + sport->dma_tx_bytes) & (UART_XMIT_SIZE - 1); + + sport->port.icount.tx += sport->dma_tx_bytes; + sport->dma_tx_in_progress = false; + spin_unlock_irqrestore(&sport->port.lock, flags); + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&sport->port); + + if (waitqueue_active(&sport->dma_wait)) { + wake_up(&sport->dma_wait); + return; + } + + spin_lock_irqsave(&sport->port.lock, flags); + + if (!lpuart_stopped_or_empty(&sport->port)) + lpuart_dma_tx(sport); + + spin_unlock_irqrestore(&sport->port.lock, flags); +} + +static dma_addr_t lpuart_dma_datareg_addr(struct lpuart_port *sport) +{ + switch (sport->port.iotype) { + case UPIO_MEM32: + return sport->port.mapbase + UARTDATA; + case UPIO_MEM32BE: + return sport->port.mapbase + UARTDATA + sizeof(u32) - 1; + } + return sport->port.mapbase + UARTDR; +} + +static int lpuart_dma_tx_request(struct uart_port *port) +{ + struct lpuart_port *sport = container_of(port, + struct lpuart_port, port); + struct dma_slave_config dma_tx_sconfig = {}; + int ret; + + dma_tx_sconfig.dst_addr = lpuart_dma_datareg_addr(sport); + dma_tx_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + dma_tx_sconfig.dst_maxburst = 1; + dma_tx_sconfig.direction = DMA_MEM_TO_DEV; + ret = dmaengine_slave_config(sport->dma_tx_chan, &dma_tx_sconfig); + + if (ret) { + dev_err(sport->port.dev, + "DMA slave config failed, err = %d\n", ret); + return ret; + } + + return 0; +} + +static bool lpuart_is_32(struct lpuart_port *sport) +{ + return sport->port.iotype == UPIO_MEM32 || + sport->port.iotype == UPIO_MEM32BE; +} + +static void lpuart_flush_buffer(struct uart_port *port) +{ + struct lpuart_port *sport = container_of(port, struct lpuart_port, port); + struct dma_chan *chan = sport->dma_tx_chan; + u32 val; + + if (sport->lpuart_dma_tx_use) { + if (sport->dma_tx_in_progress) { + dma_unmap_sg(chan->device->dev, &sport->tx_sgl[0], + sport->dma_tx_nents, DMA_TO_DEVICE); + sport->dma_tx_in_progress = false; + } + dmaengine_terminate_all(chan); + } + + if (lpuart_is_32(sport)) { + val = lpuart32_read(&sport->port, UARTFIFO); + val |= UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH; + lpuart32_write(&sport->port, val, UARTFIFO); + } else { + val = readb(sport->port.membase + UARTCFIFO); + val |= UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH; + writeb(val, sport->port.membase + UARTCFIFO); + } +} + +static void lpuart_wait_bit_set(struct uart_port *port, unsigned int offset, + u8 bit) +{ + while (!(readb(port->membase + offset) & bit)) + cpu_relax(); +} + +static void lpuart32_wait_bit_set(struct uart_port *port, unsigned int offset, + u32 bit) +{ + while (!(lpuart32_read(port, offset) & bit)) + cpu_relax(); +} + +#if defined(CONFIG_CONSOLE_POLL) + +static int lpuart_poll_init(struct uart_port *port) +{ + struct lpuart_port *sport = container_of(port, + struct lpuart_port, port); + unsigned long flags; + unsigned char temp; + + sport->port.fifosize = 0; + + spin_lock_irqsave(&sport->port.lock, flags); + /* Disable Rx & Tx */ + writeb(0, sport->port.membase + UARTCR2); + + temp = readb(sport->port.membase + UARTPFIFO); + /* Enable Rx and Tx FIFO */ + writeb(temp | UARTPFIFO_RXFE | UARTPFIFO_TXFE, + sport->port.membase + UARTPFIFO); + + /* flush Tx and Rx FIFO */ + writeb(UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH, + sport->port.membase + UARTCFIFO); + + /* explicitly clear RDRF */ + if (readb(sport->port.membase + UARTSR1) & UARTSR1_RDRF) { + readb(sport->port.membase + UARTDR); + writeb(UARTSFIFO_RXUF, sport->port.membase + UARTSFIFO); + } + + writeb(0, sport->port.membase + UARTTWFIFO); + writeb(1, sport->port.membase + UARTRWFIFO); + + /* Enable Rx and Tx */ + writeb(UARTCR2_RE | UARTCR2_TE, sport->port.membase + UARTCR2); + spin_unlock_irqrestore(&sport->port.lock, flags); + + return 0; +} + +static void lpuart_poll_put_char(struct uart_port *port, unsigned char c) +{ + /* drain */ + lpuart_wait_bit_set(port, UARTSR1, UARTSR1_TDRE); + writeb(c, port->membase + UARTDR); +} + +static int lpuart_poll_get_char(struct uart_port *port) +{ + if (!(readb(port->membase + UARTSR1) & UARTSR1_RDRF)) + return NO_POLL_CHAR; + + return readb(port->membase + UARTDR); +} + +static int lpuart32_poll_init(struct uart_port *port) +{ + unsigned long flags; + struct lpuart_port *sport = container_of(port, struct lpuart_port, port); + u32 temp; + + sport->port.fifosize = 0; + + spin_lock_irqsave(&sport->port.lock, flags); + + /* Disable Rx & Tx */ + lpuart32_write(&sport->port, 0, UARTCTRL); + + temp = lpuart32_read(&sport->port, UARTFIFO); + + /* Enable Rx and Tx FIFO */ + lpuart32_write(&sport->port, temp | UARTFIFO_RXFE | UARTFIFO_TXFE, UARTFIFO); + + /* flush Tx and Rx FIFO */ + lpuart32_write(&sport->port, UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH, UARTFIFO); + + /* explicitly clear RDRF */ + if (lpuart32_read(&sport->port, UARTSTAT) & UARTSTAT_RDRF) { + lpuart32_read(&sport->port, UARTDATA); + lpuart32_write(&sport->port, UARTFIFO_RXUF, UARTFIFO); + } + + /* Enable Rx and Tx */ + lpuart32_write(&sport->port, UARTCTRL_RE | UARTCTRL_TE, UARTCTRL); + spin_unlock_irqrestore(&sport->port.lock, flags); + + return 0; +} + +static void lpuart32_poll_put_char(struct uart_port *port, unsigned char c) +{ + lpuart32_wait_bit_set(port, UARTSTAT, UARTSTAT_TDRE); + lpuart32_write(port, c, UARTDATA); +} + +static int lpuart32_poll_get_char(struct uart_port *port) +{ + if (!(lpuart32_read(port, UARTWATER) >> UARTWATER_RXCNT_OFF)) + return NO_POLL_CHAR; + + return lpuart32_read(port, UARTDATA); +} +#endif + +static inline void lpuart_transmit_buffer(struct lpuart_port *sport) +{ + struct circ_buf *xmit = &sport->port.state->xmit; + + if (sport->port.x_char) { + writeb(sport->port.x_char, sport->port.membase + UARTDR); + sport->port.icount.tx++; + sport->port.x_char = 0; + return; + } + + if (lpuart_stopped_or_empty(&sport->port)) { + lpuart_stop_tx(&sport->port); + return; + } + + while (!uart_circ_empty(xmit) && + (readb(sport->port.membase + UARTTCFIFO) < sport->txfifo_size)) { + writeb(xmit->buf[xmit->tail], sport->port.membase + UARTDR); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + sport->port.icount.tx++; + } + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&sport->port); + + if (uart_circ_empty(xmit)) + lpuart_stop_tx(&sport->port); +} + +static inline void lpuart32_transmit_buffer(struct lpuart_port *sport) +{ + struct circ_buf *xmit = &sport->port.state->xmit; + unsigned long txcnt; + + if (sport->port.x_char) { + lpuart32_write(&sport->port, sport->port.x_char, UARTDATA); + sport->port.icount.tx++; + sport->port.x_char = 0; + return; + } + + if (lpuart_stopped_or_empty(&sport->port)) { + lpuart32_stop_tx(&sport->port); + return; + } + + txcnt = lpuart32_read(&sport->port, UARTWATER); + txcnt = txcnt >> UARTWATER_TXCNT_OFF; + txcnt &= UARTWATER_COUNT_MASK; + while (!uart_circ_empty(xmit) && (txcnt < sport->txfifo_size)) { + lpuart32_write(&sport->port, xmit->buf[xmit->tail], UARTDATA); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + sport->port.icount.tx++; + txcnt = lpuart32_read(&sport->port, UARTWATER); + txcnt = txcnt >> UARTWATER_TXCNT_OFF; + txcnt &= UARTWATER_COUNT_MASK; + } + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&sport->port); + + if (uart_circ_empty(xmit)) + lpuart32_stop_tx(&sport->port); +} + +static void lpuart_start_tx(struct uart_port *port) +{ + struct lpuart_port *sport = container_of(port, + struct lpuart_port, port); + unsigned char temp; + + temp = readb(port->membase + UARTCR2); + writeb(temp | UARTCR2_TIE, port->membase + UARTCR2); + + if (sport->lpuart_dma_tx_use) { + if (!lpuart_stopped_or_empty(port)) + lpuart_dma_tx(sport); + } else { + if (readb(port->membase + UARTSR1) & UARTSR1_TDRE) + lpuart_transmit_buffer(sport); + } +} + +static void lpuart32_start_tx(struct uart_port *port) +{ + struct lpuart_port *sport = container_of(port, struct lpuart_port, port); + unsigned long temp; + + if (sport->lpuart_dma_tx_use) { + if (!lpuart_stopped_or_empty(port)) + lpuart_dma_tx(sport); + } else { + temp = lpuart32_read(port, UARTCTRL); + lpuart32_write(port, temp | UARTCTRL_TIE, UARTCTRL); + + if (lpuart32_read(port, UARTSTAT) & UARTSTAT_TDRE) + lpuart32_transmit_buffer(sport); + } +} + +/* return TIOCSER_TEMT when transmitter is not busy */ +static unsigned int lpuart_tx_empty(struct uart_port *port) +{ + struct lpuart_port *sport = container_of(port, + struct lpuart_port, port); + unsigned char sr1 = readb(port->membase + UARTSR1); + unsigned char sfifo = readb(port->membase + UARTSFIFO); + + if (sport->dma_tx_in_progress) + return 0; + + if (sr1 & UARTSR1_TC && sfifo & UARTSFIFO_TXEMPT) + return TIOCSER_TEMT; + + return 0; +} + +static unsigned int lpuart32_tx_empty(struct uart_port *port) +{ + struct lpuart_port *sport = container_of(port, + struct lpuart_port, port); + unsigned long stat = lpuart32_read(port, UARTSTAT); + unsigned long sfifo = lpuart32_read(port, UARTFIFO); + unsigned long ctrl = lpuart32_read(port, UARTCTRL); + + if (sport->dma_tx_in_progress) + return 0; + + /* + * LPUART Transmission Complete Flag may never be set while queuing a break + * character, so avoid checking for transmission complete when UARTCTRL_SBK + * is asserted. + */ + if ((stat & UARTSTAT_TC && sfifo & UARTFIFO_TXEMPT) || ctrl & UARTCTRL_SBK) + return TIOCSER_TEMT; + + return 0; +} + +static void lpuart_txint(struct lpuart_port *sport) +{ + unsigned long flags; + + spin_lock_irqsave(&sport->port.lock, flags); + lpuart_transmit_buffer(sport); + spin_unlock_irqrestore(&sport->port.lock, flags); +} + +static void lpuart_rxint(struct lpuart_port *sport) +{ + unsigned int flg, ignored = 0, overrun = 0; + struct tty_port *port = &sport->port.state->port; + unsigned long flags; + unsigned char rx, sr; + + spin_lock_irqsave(&sport->port.lock, flags); + + while (!(readb(sport->port.membase + UARTSFIFO) & UARTSFIFO_RXEMPT)) { + flg = TTY_NORMAL; + sport->port.icount.rx++; + /* + * to clear the FE, OR, NF, FE, PE flags, + * read SR1 then read DR + */ + sr = readb(sport->port.membase + UARTSR1); + rx = readb(sport->port.membase + UARTDR); + + if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx)) + continue; + + if (sr & (UARTSR1_PE | UARTSR1_OR | UARTSR1_FE)) { + if (sr & UARTSR1_PE) + sport->port.icount.parity++; + else if (sr & UARTSR1_FE) + sport->port.icount.frame++; + + if (sr & UARTSR1_OR) + overrun++; + + if (sr & sport->port.ignore_status_mask) { + if (++ignored > 100) + goto out; + continue; + } + + sr &= sport->port.read_status_mask; + + if (sr & UARTSR1_PE) + flg = TTY_PARITY; + else if (sr & UARTSR1_FE) + flg = TTY_FRAME; + + if (sr & UARTSR1_OR) + flg = TTY_OVERRUN; + + sport->port.sysrq = 0; + } + + tty_insert_flip_char(port, rx, flg); + } + +out: + if (overrun) { + sport->port.icount.overrun += overrun; + + /* + * Overruns cause FIFO pointers to become missaligned. + * Flushing the receive FIFO reinitializes the pointers. + */ + writeb(UARTCFIFO_RXFLUSH, sport->port.membase + UARTCFIFO); + writeb(UARTSFIFO_RXOF, sport->port.membase + UARTSFIFO); + } + + spin_unlock_irqrestore(&sport->port.lock, flags); + + tty_flip_buffer_push(port); +} + +static void lpuart32_txint(struct lpuart_port *sport) +{ + unsigned long flags; + + spin_lock_irqsave(&sport->port.lock, flags); + lpuart32_transmit_buffer(sport); + spin_unlock_irqrestore(&sport->port.lock, flags); +} + +static void lpuart32_rxint(struct lpuart_port *sport) +{ + unsigned int flg, ignored = 0; + struct tty_port *port = &sport->port.state->port; + unsigned long flags; + unsigned long rx, sr; + + spin_lock_irqsave(&sport->port.lock, flags); + + while (!(lpuart32_read(&sport->port, UARTFIFO) & UARTFIFO_RXEMPT)) { + flg = TTY_NORMAL; + sport->port.icount.rx++; + /* + * to clear the FE, OR, NF, FE, PE flags, + * read STAT then read DATA reg + */ + sr = lpuart32_read(&sport->port, UARTSTAT); + rx = lpuart32_read(&sport->port, UARTDATA); + rx &= 0x3ff; + + if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx)) + continue; + + if (sr & (UARTSTAT_PE | UARTSTAT_OR | UARTSTAT_FE)) { + if (sr & UARTSTAT_PE) + sport->port.icount.parity++; + else if (sr & UARTSTAT_FE) + sport->port.icount.frame++; + + if (sr & UARTSTAT_OR) + sport->port.icount.overrun++; + + if (sr & sport->port.ignore_status_mask) { + if (++ignored > 100) + goto out; + continue; + } + + sr &= sport->port.read_status_mask; + + if (sr & UARTSTAT_PE) + flg = TTY_PARITY; + else if (sr & UARTSTAT_FE) + flg = TTY_FRAME; + + if (sr & UARTSTAT_OR) + flg = TTY_OVERRUN; + + sport->port.sysrq = 0; + } + + tty_insert_flip_char(port, rx, flg); + } + +out: + spin_unlock_irqrestore(&sport->port.lock, flags); + + tty_flip_buffer_push(port); +} + +static irqreturn_t lpuart_int(int irq, void *dev_id) +{ + struct lpuart_port *sport = dev_id; + unsigned char sts; + + sts = readb(sport->port.membase + UARTSR1); + + /* SysRq, using dma, check for linebreak by framing err. */ + if (sts & UARTSR1_FE && sport->lpuart_dma_rx_use) { + readb(sport->port.membase + UARTDR); + uart_handle_break(&sport->port); + /* linebreak produces some garbage, removing it */ + writeb(UARTCFIFO_RXFLUSH, sport->port.membase + UARTCFIFO); + return IRQ_HANDLED; + } + + if (sts & UARTSR1_RDRF && !sport->lpuart_dma_rx_use) + lpuart_rxint(sport); + + if (sts & UARTSR1_TDRE && !sport->lpuart_dma_tx_use) + lpuart_txint(sport); + + return IRQ_HANDLED; +} + +static irqreturn_t lpuart32_int(int irq, void *dev_id) +{ + struct lpuart_port *sport = dev_id; + unsigned long sts, rxcount; + + sts = lpuart32_read(&sport->port, UARTSTAT); + rxcount = lpuart32_read(&sport->port, UARTWATER); + rxcount = rxcount >> UARTWATER_RXCNT_OFF; + + if ((sts & UARTSTAT_RDRF || rxcount > 0) && !sport->lpuart_dma_rx_use) + lpuart32_rxint(sport); + + if ((sts & UARTSTAT_TDRE) && !sport->lpuart_dma_tx_use) + lpuart32_txint(sport); + + lpuart32_write(&sport->port, sts, UARTSTAT); + return IRQ_HANDLED; +} + + +static inline void lpuart_handle_sysrq_chars(struct uart_port *port, + unsigned char *p, int count) +{ + while (count--) { + if (*p && uart_handle_sysrq_char(port, *p)) + return; + p++; + } +} + +static void lpuart_handle_sysrq(struct lpuart_port *sport) +{ + struct circ_buf *ring = &sport->rx_ring; + int count; + + if (ring->head < ring->tail) { + count = sport->rx_sgl.length - ring->tail; + lpuart_handle_sysrq_chars(&sport->port, + ring->buf + ring->tail, count); + ring->tail = 0; + } + + if (ring->head > ring->tail) { + count = ring->head - ring->tail; + lpuart_handle_sysrq_chars(&sport->port, + ring->buf + ring->tail, count); + ring->tail = ring->head; + } +} + +static void lpuart_copy_rx_to_tty(struct lpuart_port *sport) +{ + struct tty_port *port = &sport->port.state->port; + struct dma_tx_state state; + enum dma_status dmastat; + struct dma_chan *chan = sport->dma_rx_chan; + struct circ_buf *ring = &sport->rx_ring; + unsigned long flags; + int count = 0; + + if (lpuart_is_32(sport)) { + unsigned long sr = lpuart32_read(&sport->port, UARTSTAT); + + if (sr & (UARTSTAT_PE | UARTSTAT_FE)) { + /* Clear the error flags */ + lpuart32_write(&sport->port, sr, UARTSTAT); + + if (sr & UARTSTAT_PE) + sport->port.icount.parity++; + else if (sr & UARTSTAT_FE) + sport->port.icount.frame++; + } + } else { + unsigned char sr = readb(sport->port.membase + UARTSR1); + + if (sr & (UARTSR1_PE | UARTSR1_FE)) { + unsigned char cr2; + + /* Disable receiver during this operation... */ + cr2 = readb(sport->port.membase + UARTCR2); + cr2 &= ~UARTCR2_RE; + writeb(cr2, sport->port.membase + UARTCR2); + + /* Read DR to clear the error flags */ + readb(sport->port.membase + UARTDR); + + if (sr & UARTSR1_PE) + sport->port.icount.parity++; + else if (sr & UARTSR1_FE) + sport->port.icount.frame++; + /* + * At this point parity/framing error is + * cleared However, since the DMA already read + * the data register and we had to read it + * again after reading the status register to + * properly clear the flags, the FIFO actually + * underflowed... This requires a clearing of + * the FIFO... + */ + if (readb(sport->port.membase + UARTSFIFO) & + UARTSFIFO_RXUF) { + writeb(UARTSFIFO_RXUF, + sport->port.membase + UARTSFIFO); + writeb(UARTCFIFO_RXFLUSH, + sport->port.membase + UARTCFIFO); + } + + cr2 |= UARTCR2_RE; + writeb(cr2, sport->port.membase + UARTCR2); + } + } + + async_tx_ack(sport->dma_rx_desc); + + spin_lock_irqsave(&sport->port.lock, flags); + + dmastat = dmaengine_tx_status(chan, sport->dma_rx_cookie, &state); + if (dmastat == DMA_ERROR) { + dev_err(sport->port.dev, "Rx DMA transfer failed!\n"); + spin_unlock_irqrestore(&sport->port.lock, flags); + return; + } + + /* CPU claims ownership of RX DMA buffer */ + dma_sync_sg_for_cpu(chan->device->dev, &sport->rx_sgl, 1, + DMA_FROM_DEVICE); + + /* + * ring->head points to the end of data already written by the DMA. + * ring->tail points to the beginning of data to be read by the + * framework. + * The current transfer size should not be larger than the dma buffer + * length. + */ + ring->head = sport->rx_sgl.length - state.residue; + BUG_ON(ring->head > sport->rx_sgl.length); + + /* + * Silent handling of keys pressed in the sysrq timeframe + */ + if (sport->port.sysrq) { + lpuart_handle_sysrq(sport); + goto exit; + } + + /* + * At this point ring->head may point to the first byte right after the + * last byte of the dma buffer: + * 0 <= ring->head <= sport->rx_sgl.length + * + * However ring->tail must always points inside the dma buffer: + * 0 <= ring->tail <= sport->rx_sgl.length - 1 + * + * Since we use a ring buffer, we have to handle the case + * where head is lower than tail. In such a case, we first read from + * tail to the end of the buffer then reset tail. + */ + if (ring->head < ring->tail) { + count = sport->rx_sgl.length - ring->tail; + + tty_insert_flip_string(port, ring->buf + ring->tail, count); + ring->tail = 0; + sport->port.icount.rx += count; + } + + /* Finally we read data from tail to head */ + if (ring->tail < ring->head) { + count = ring->head - ring->tail; + tty_insert_flip_string(port, ring->buf + ring->tail, count); + /* Wrap ring->head if needed */ + if (ring->head >= sport->rx_sgl.length) + ring->head = 0; + ring->tail = ring->head; + sport->port.icount.rx += count; + } + +exit: + dma_sync_sg_for_device(chan->device->dev, &sport->rx_sgl, 1, + DMA_FROM_DEVICE); + + spin_unlock_irqrestore(&sport->port.lock, flags); + + tty_flip_buffer_push(port); + mod_timer(&sport->lpuart_timer, jiffies + sport->dma_rx_timeout); +} + +static void lpuart_dma_rx_complete(void *arg) +{ + struct lpuart_port *sport = arg; + + lpuart_copy_rx_to_tty(sport); +} + +static void lpuart_timer_func(struct timer_list *t) +{ + struct lpuart_port *sport = from_timer(sport, t, lpuart_timer); + + lpuart_copy_rx_to_tty(sport); +} + +static inline int lpuart_start_rx_dma(struct lpuart_port *sport) +{ + struct dma_slave_config dma_rx_sconfig = {}; + struct circ_buf *ring = &sport->rx_ring; + int ret, nent; + int bits, baud; + struct tty_port *port = &sport->port.state->port; + struct tty_struct *tty = port->tty; + struct ktermios *termios = &tty->termios; + struct dma_chan *chan = sport->dma_rx_chan; + + baud = tty_get_baud_rate(tty); + + bits = (termios->c_cflag & CSIZE) == CS7 ? 9 : 10; + if (termios->c_cflag & PARENB) + bits++; + + /* + * Calculate length of one DMA buffer size to keep latency below + * 10ms at any baud rate. + */ + sport->rx_dma_rng_buf_len = (DMA_RX_TIMEOUT * baud / bits / 1000) * 2; + sport->rx_dma_rng_buf_len = (1 << fls(sport->rx_dma_rng_buf_len)); + if (sport->rx_dma_rng_buf_len < 16) + sport->rx_dma_rng_buf_len = 16; + + ring->buf = kzalloc(sport->rx_dma_rng_buf_len, GFP_ATOMIC); + if (!ring->buf) + return -ENOMEM; + + sg_init_one(&sport->rx_sgl, ring->buf, sport->rx_dma_rng_buf_len); + nent = dma_map_sg(chan->device->dev, &sport->rx_sgl, 1, + DMA_FROM_DEVICE); + + if (!nent) { + dev_err(sport->port.dev, "DMA Rx mapping error\n"); + return -EINVAL; + } + + dma_rx_sconfig.src_addr = lpuart_dma_datareg_addr(sport); + dma_rx_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + dma_rx_sconfig.src_maxburst = 1; + dma_rx_sconfig.direction = DMA_DEV_TO_MEM; + ret = dmaengine_slave_config(chan, &dma_rx_sconfig); + + if (ret < 0) { + dev_err(sport->port.dev, + "DMA Rx slave config failed, err = %d\n", ret); + return ret; + } + + sport->dma_rx_desc = dmaengine_prep_dma_cyclic(chan, + sg_dma_address(&sport->rx_sgl), + sport->rx_sgl.length, + sport->rx_sgl.length / 2, + DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT); + if (!sport->dma_rx_desc) { + dev_err(sport->port.dev, "Cannot prepare cyclic DMA\n"); + return -EFAULT; + } + + sport->dma_rx_desc->callback = lpuart_dma_rx_complete; + sport->dma_rx_desc->callback_param = sport; + sport->dma_rx_cookie = dmaengine_submit(sport->dma_rx_desc); + dma_async_issue_pending(chan); + + if (lpuart_is_32(sport)) { + unsigned long temp = lpuart32_read(&sport->port, UARTBAUD); + + lpuart32_write(&sport->port, temp | UARTBAUD_RDMAE, UARTBAUD); + } else { + writeb(readb(sport->port.membase + UARTCR5) | UARTCR5_RDMAS, + sport->port.membase + UARTCR5); + } + + return 0; +} + +static void lpuart_dma_rx_free(struct uart_port *port) +{ + struct lpuart_port *sport = container_of(port, + struct lpuart_port, port); + struct dma_chan *chan = sport->dma_rx_chan; + + dmaengine_terminate_all(chan); + del_timer_sync(&sport->lpuart_timer); + dma_unmap_sg(chan->device->dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE); + kfree(sport->rx_ring.buf); + sport->rx_ring.tail = 0; + sport->rx_ring.head = 0; + sport->dma_rx_desc = NULL; + sport->dma_rx_cookie = -EINVAL; +} + +static int lpuart_config_rs485(struct uart_port *port, + struct serial_rs485 *rs485) +{ + struct lpuart_port *sport = container_of(port, + struct lpuart_port, port); + + u8 modem = readb(sport->port.membase + UARTMODEM) & + ~(UARTMODEM_TXRTSPOL | UARTMODEM_TXRTSE); + writeb(modem, sport->port.membase + UARTMODEM); + + /* clear unsupported configurations */ + rs485->delay_rts_before_send = 0; + rs485->delay_rts_after_send = 0; + rs485->flags &= ~SER_RS485_RX_DURING_TX; + + if (rs485->flags & SER_RS485_ENABLED) { + /* Enable auto RS-485 RTS mode */ + modem |= UARTMODEM_TXRTSE; + + /* + * RTS needs to be logic HIGH either during transfer _or_ after + * transfer, other variants are not supported by the hardware. + */ + + if (!(rs485->flags & (SER_RS485_RTS_ON_SEND | + SER_RS485_RTS_AFTER_SEND))) + rs485->flags |= SER_RS485_RTS_ON_SEND; + + if (rs485->flags & SER_RS485_RTS_ON_SEND && + rs485->flags & SER_RS485_RTS_AFTER_SEND) + rs485->flags &= ~SER_RS485_RTS_AFTER_SEND; + + /* + * The hardware defaults to RTS logic HIGH while transfer. + * Switch polarity in case RTS shall be logic HIGH + * after transfer. + * Note: UART is assumed to be active high. + */ + if (rs485->flags & SER_RS485_RTS_ON_SEND) + modem &= ~UARTMODEM_TXRTSPOL; + else if (rs485->flags & SER_RS485_RTS_AFTER_SEND) + modem |= UARTMODEM_TXRTSPOL; + } + + /* Store the new configuration */ + sport->port.rs485 = *rs485; + + writeb(modem, sport->port.membase + UARTMODEM); + return 0; +} + +static int lpuart32_config_rs485(struct uart_port *port, + struct serial_rs485 *rs485) +{ + struct lpuart_port *sport = container_of(port, + struct lpuart_port, port); + + unsigned long modem = lpuart32_read(&sport->port, UARTMODIR) + & ~(UARTMODEM_TXRTSPOL | UARTMODEM_TXRTSE); + lpuart32_write(&sport->port, modem, UARTMODIR); + + /* clear unsupported configurations */ + rs485->delay_rts_before_send = 0; + rs485->delay_rts_after_send = 0; + rs485->flags &= ~SER_RS485_RX_DURING_TX; + + if (rs485->flags & SER_RS485_ENABLED) { + /* Enable auto RS-485 RTS mode */ + modem |= UARTMODEM_TXRTSE; + + /* + * RTS needs to be logic HIGH either during transfer _or_ after + * transfer, other variants are not supported by the hardware. + */ + + if (!(rs485->flags & (SER_RS485_RTS_ON_SEND | + SER_RS485_RTS_AFTER_SEND))) + rs485->flags |= SER_RS485_RTS_ON_SEND; + + if (rs485->flags & SER_RS485_RTS_ON_SEND && + rs485->flags & SER_RS485_RTS_AFTER_SEND) + rs485->flags &= ~SER_RS485_RTS_AFTER_SEND; + + /* + * The hardware defaults to RTS logic HIGH while transfer. + * Switch polarity in case RTS shall be logic HIGH + * after transfer. + * Note: UART is assumed to be active high. + */ + if (rs485->flags & SER_RS485_RTS_ON_SEND) + modem |= UARTMODEM_TXRTSPOL; + else if (rs485->flags & SER_RS485_RTS_AFTER_SEND) + modem &= ~UARTMODEM_TXRTSPOL; + } + + /* Store the new configuration */ + sport->port.rs485 = *rs485; + + lpuart32_write(&sport->port, modem, UARTMODIR); + return 0; +} + +static unsigned int lpuart_get_mctrl(struct uart_port *port) +{ + unsigned int temp = 0; + unsigned char reg; + + reg = readb(port->membase + UARTMODEM); + if (reg & UARTMODEM_TXCTSE) + temp |= TIOCM_CTS; + + if (reg & UARTMODEM_RXRTSE) + temp |= TIOCM_RTS; + + return temp; +} + +static unsigned int lpuart32_get_mctrl(struct uart_port *port) +{ + return 0; +} + +static void lpuart_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + unsigned char temp; + struct lpuart_port *sport = container_of(port, + struct lpuart_port, port); + + /* Make sure RXRTSE bit is not set when RS485 is enabled */ + if (!(sport->port.rs485.flags & SER_RS485_ENABLED)) { + temp = readb(sport->port.membase + UARTMODEM) & + ~(UARTMODEM_RXRTSE | UARTMODEM_TXCTSE); + + if (mctrl & TIOCM_RTS) + temp |= UARTMODEM_RXRTSE; + + if (mctrl & TIOCM_CTS) + temp |= UARTMODEM_TXCTSE; + + writeb(temp, port->membase + UARTMODEM); + } +} + +static void lpuart32_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + +} + +static void lpuart_break_ctl(struct uart_port *port, int break_state) +{ + unsigned char temp; + + temp = readb(port->membase + UARTCR2) & ~UARTCR2_SBK; + + if (break_state != 0) + temp |= UARTCR2_SBK; + + writeb(temp, port->membase + UARTCR2); +} + +static void lpuart32_break_ctl(struct uart_port *port, int break_state) +{ + unsigned long temp; + + temp = lpuart32_read(port, UARTCTRL); + + /* + * LPUART IP now has two known bugs, one is CTS has higher priority than the + * break signal, which causes the break signal sending through UARTCTRL_SBK + * may impacted by the CTS input if the HW flow control is enabled. It + * exists on all platforms we support in this driver. + * Another bug is i.MX8QM LPUART may have an additional break character + * being sent after SBK was cleared. + * To avoid above two bugs, we use Transmit Data Inversion function to send + * the break signal instead of UARTCTRL_SBK. + */ + if (break_state != 0) { + /* + * Disable the transmitter to prevent any data from being sent out + * during break, then invert the TX line to send break. + */ + temp &= ~UARTCTRL_TE; + lpuart32_write(port, temp, UARTCTRL); + temp |= UARTCTRL_TXINV; + lpuart32_write(port, temp, UARTCTRL); + } else { + /* Disable the TXINV to turn off break and re-enable transmitter. */ + temp &= ~UARTCTRL_TXINV; + lpuart32_write(port, temp, UARTCTRL); + temp |= UARTCTRL_TE; + lpuart32_write(port, temp, UARTCTRL); + } +} + +static void lpuart_setup_watermark(struct lpuart_port *sport) +{ + unsigned char val, cr2; + unsigned char cr2_saved; + + cr2 = readb(sport->port.membase + UARTCR2); + cr2_saved = cr2; + cr2 &= ~(UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_TE | + UARTCR2_RIE | UARTCR2_RE); + writeb(cr2, sport->port.membase + UARTCR2); + + val = readb(sport->port.membase + UARTPFIFO); + writeb(val | UARTPFIFO_TXFE | UARTPFIFO_RXFE, + sport->port.membase + UARTPFIFO); + + /* flush Tx and Rx FIFO */ + writeb(UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH, + sport->port.membase + UARTCFIFO); + + /* explicitly clear RDRF */ + if (readb(sport->port.membase + UARTSR1) & UARTSR1_RDRF) { + readb(sport->port.membase + UARTDR); + writeb(UARTSFIFO_RXUF, sport->port.membase + UARTSFIFO); + } + + writeb(0, sport->port.membase + UARTTWFIFO); + writeb(1, sport->port.membase + UARTRWFIFO); + + /* Restore cr2 */ + writeb(cr2_saved, sport->port.membase + UARTCR2); +} + +static void lpuart_setup_watermark_enable(struct lpuart_port *sport) +{ + unsigned char cr2; + + lpuart_setup_watermark(sport); + + cr2 = readb(sport->port.membase + UARTCR2); + cr2 |= UARTCR2_RIE | UARTCR2_RE | UARTCR2_TE; + writeb(cr2, sport->port.membase + UARTCR2); +} + +static void lpuart32_setup_watermark(struct lpuart_port *sport) +{ + unsigned long val, ctrl; + unsigned long ctrl_saved; + + ctrl = lpuart32_read(&sport->port, UARTCTRL); + ctrl_saved = ctrl; + ctrl &= ~(UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_TE | + UARTCTRL_RIE | UARTCTRL_RE); + lpuart32_write(&sport->port, ctrl, UARTCTRL); + + /* enable FIFO mode */ + val = lpuart32_read(&sport->port, UARTFIFO); + val |= UARTFIFO_TXFE | UARTFIFO_RXFE; + val |= UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH; + lpuart32_write(&sport->port, val, UARTFIFO); + + /* set the watermark */ + val = (0x1 << UARTWATER_RXWATER_OFF) | (0x0 << UARTWATER_TXWATER_OFF); + lpuart32_write(&sport->port, val, UARTWATER); + + /* Restore cr2 */ + lpuart32_write(&sport->port, ctrl_saved, UARTCTRL); +} + +static void lpuart32_setup_watermark_enable(struct lpuart_port *sport) +{ + u32 temp; + + lpuart32_setup_watermark(sport); + + temp = lpuart32_read(&sport->port, UARTCTRL); + temp |= UARTCTRL_RE | UARTCTRL_TE | UARTCTRL_ILIE; + lpuart32_write(&sport->port, temp, UARTCTRL); +} + +static void rx_dma_timer_init(struct lpuart_port *sport) +{ + timer_setup(&sport->lpuart_timer, lpuart_timer_func, 0); + sport->lpuart_timer.expires = jiffies + sport->dma_rx_timeout; + add_timer(&sport->lpuart_timer); +} + +static void lpuart_request_dma(struct lpuart_port *sport) +{ + sport->dma_tx_chan = dma_request_chan(sport->port.dev, "tx"); + if (IS_ERR(sport->dma_tx_chan)) { + dev_dbg_once(sport->port.dev, + "DMA tx channel request failed, operating without tx DMA (%ld)\n", + PTR_ERR(sport->dma_tx_chan)); + sport->dma_tx_chan = NULL; + } + + sport->dma_rx_chan = dma_request_chan(sport->port.dev, "rx"); + if (IS_ERR(sport->dma_rx_chan)) { + dev_dbg_once(sport->port.dev, + "DMA rx channel request failed, operating without rx DMA (%ld)\n", + PTR_ERR(sport->dma_rx_chan)); + sport->dma_rx_chan = NULL; + } +} + +static void lpuart_tx_dma_startup(struct lpuart_port *sport) +{ + u32 uartbaud; + int ret; + + if (uart_console(&sport->port)) + goto err; + + if (!sport->dma_tx_chan) + goto err; + + ret = lpuart_dma_tx_request(&sport->port); + if (ret) + goto err; + + init_waitqueue_head(&sport->dma_wait); + sport->lpuart_dma_tx_use = true; + if (lpuart_is_32(sport)) { + uartbaud = lpuart32_read(&sport->port, UARTBAUD); + lpuart32_write(&sport->port, + uartbaud | UARTBAUD_TDMAE, UARTBAUD); + } else { + writeb(readb(sport->port.membase + UARTCR5) | + UARTCR5_TDMAS, sport->port.membase + UARTCR5); + } + + return; + +err: + sport->lpuart_dma_tx_use = false; +} + +static void lpuart_rx_dma_startup(struct lpuart_port *sport) +{ + int ret; + unsigned char cr3; + + if (uart_console(&sport->port)) + goto err; + + if (!sport->dma_rx_chan) + goto err; + + ret = lpuart_start_rx_dma(sport); + if (ret) + goto err; + + /* set Rx DMA timeout */ + sport->dma_rx_timeout = msecs_to_jiffies(DMA_RX_TIMEOUT); + if (!sport->dma_rx_timeout) + sport->dma_rx_timeout = 1; + + sport->lpuart_dma_rx_use = true; + rx_dma_timer_init(sport); + + if (sport->port.has_sysrq && !lpuart_is_32(sport)) { + cr3 = readb(sport->port.membase + UARTCR3); + cr3 |= UARTCR3_FEIE; + writeb(cr3, sport->port.membase + UARTCR3); + } + + return; + +err: + sport->lpuart_dma_rx_use = false; +} + +static int lpuart_startup(struct uart_port *port) +{ + struct lpuart_port *sport = container_of(port, struct lpuart_port, port); + unsigned long flags; + unsigned char temp; + + /* determine FIFO size and enable FIFO mode */ + temp = readb(sport->port.membase + UARTPFIFO); + + sport->txfifo_size = UARTFIFO_DEPTH((temp >> UARTPFIFO_TXSIZE_OFF) & + UARTPFIFO_FIFOSIZE_MASK); + sport->port.fifosize = sport->txfifo_size; + + sport->rxfifo_size = UARTFIFO_DEPTH((temp >> UARTPFIFO_RXSIZE_OFF) & + UARTPFIFO_FIFOSIZE_MASK); + + lpuart_request_dma(sport); + + spin_lock_irqsave(&sport->port.lock, flags); + + lpuart_setup_watermark_enable(sport); + + lpuart_rx_dma_startup(sport); + lpuart_tx_dma_startup(sport); + + spin_unlock_irqrestore(&sport->port.lock, flags); + + return 0; +} + +static void lpuart32_configure(struct lpuart_port *sport) +{ + unsigned long temp; + + if (sport->lpuart_dma_rx_use) { + /* RXWATER must be 0 */ + temp = lpuart32_read(&sport->port, UARTWATER); + temp &= ~(UARTWATER_WATER_MASK << UARTWATER_RXWATER_OFF); + lpuart32_write(&sport->port, temp, UARTWATER); + } + temp = lpuart32_read(&sport->port, UARTCTRL); + if (!sport->lpuart_dma_rx_use) + temp |= UARTCTRL_RIE; + if (!sport->lpuart_dma_tx_use) + temp |= UARTCTRL_TIE; + lpuart32_write(&sport->port, temp, UARTCTRL); +} + +static int lpuart32_startup(struct uart_port *port) +{ + struct lpuart_port *sport = container_of(port, struct lpuart_port, port); + unsigned long flags; + unsigned long temp; + + /* determine FIFO size */ + temp = lpuart32_read(&sport->port, UARTFIFO); + + sport->txfifo_size = UARTFIFO_DEPTH((temp >> UARTFIFO_TXSIZE_OFF) & + UARTFIFO_FIFOSIZE_MASK); + sport->port.fifosize = sport->txfifo_size; + + sport->rxfifo_size = UARTFIFO_DEPTH((temp >> UARTFIFO_RXSIZE_OFF) & + UARTFIFO_FIFOSIZE_MASK); + + /* + * The LS1021A and LS1028A have a fixed FIFO depth of 16 words. + * Although they support the RX/TXSIZE fields, their encoding is + * different. Eg the reference manual states 0b101 is 16 words. + */ + if (is_layerscape_lpuart(sport)) { + sport->rxfifo_size = 16; + sport->txfifo_size = 16; + sport->port.fifosize = sport->txfifo_size; + } + + lpuart_request_dma(sport); + + spin_lock_irqsave(&sport->port.lock, flags); + + lpuart32_setup_watermark_enable(sport); + + lpuart_rx_dma_startup(sport); + lpuart_tx_dma_startup(sport); + + lpuart32_configure(sport); + + spin_unlock_irqrestore(&sport->port.lock, flags); + return 0; +} + +static void lpuart_dma_shutdown(struct lpuart_port *sport) +{ + if (sport->lpuart_dma_rx_use) { + lpuart_dma_rx_free(&sport->port); + sport->lpuart_dma_rx_use = false; + } + + if (sport->lpuart_dma_tx_use) { + if (wait_event_interruptible(sport->dma_wait, + !sport->dma_tx_in_progress) != false) { + sport->dma_tx_in_progress = false; + dmaengine_terminate_all(sport->dma_tx_chan); + } + sport->lpuart_dma_tx_use = false; + } + + if (sport->dma_tx_chan) + dma_release_channel(sport->dma_tx_chan); + if (sport->dma_rx_chan) + dma_release_channel(sport->dma_rx_chan); +} + +static void lpuart_shutdown(struct uart_port *port) +{ + struct lpuart_port *sport = container_of(port, struct lpuart_port, port); + unsigned char temp; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + + /* disable Rx/Tx and interrupts */ + temp = readb(port->membase + UARTCR2); + temp &= ~(UARTCR2_TE | UARTCR2_RE | + UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_RIE); + writeb(temp, port->membase + UARTCR2); + + spin_unlock_irqrestore(&port->lock, flags); + + lpuart_dma_shutdown(sport); +} + +static void lpuart32_shutdown(struct uart_port *port) +{ + struct lpuart_port *sport = + container_of(port, struct lpuart_port, port); + unsigned long temp; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + + /* disable Rx/Tx and interrupts */ + temp = lpuart32_read(port, UARTCTRL); + temp &= ~(UARTCTRL_TE | UARTCTRL_RE | + UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_RIE); + lpuart32_write(port, temp, UARTCTRL); + + spin_unlock_irqrestore(&port->lock, flags); + + lpuart_dma_shutdown(sport); +} + +static void +lpuart_set_termios(struct uart_port *port, struct ktermios *termios, + struct ktermios *old) +{ + struct lpuart_port *sport = container_of(port, struct lpuart_port, port); + unsigned long flags; + unsigned char cr1, old_cr1, old_cr2, cr3, cr4, bdh, modem; + unsigned int baud; + unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8; + unsigned int sbr, brfa; + + cr1 = old_cr1 = readb(sport->port.membase + UARTCR1); + old_cr2 = readb(sport->port.membase + UARTCR2); + cr3 = readb(sport->port.membase + UARTCR3); + cr4 = readb(sport->port.membase + UARTCR4); + bdh = readb(sport->port.membase + UARTBDH); + modem = readb(sport->port.membase + UARTMODEM); + /* + * only support CS8 and CS7, and for CS7 must enable PE. + * supported mode: + * - (7,e/o,1) + * - (8,n,1) + * - (8,m/s,1) + * - (8,e/o,1) + */ + while ((termios->c_cflag & CSIZE) != CS8 && + (termios->c_cflag & CSIZE) != CS7) { + termios->c_cflag &= ~CSIZE; + termios->c_cflag |= old_csize; + old_csize = CS8; + } + + if ((termios->c_cflag & CSIZE) == CS8 || + (termios->c_cflag & CSIZE) == CS7) + cr1 = old_cr1 & ~UARTCR1_M; + + if (termios->c_cflag & CMSPAR) { + if ((termios->c_cflag & CSIZE) != CS8) { + termios->c_cflag &= ~CSIZE; + termios->c_cflag |= CS8; + } + cr1 |= UARTCR1_M; + } + + /* + * When auto RS-485 RTS mode is enabled, + * hardware flow control need to be disabled. + */ + if (sport->port.rs485.flags & SER_RS485_ENABLED) + termios->c_cflag &= ~CRTSCTS; + + if (termios->c_cflag & CRTSCTS) + modem |= UARTMODEM_RXRTSE | UARTMODEM_TXCTSE; + else + modem &= ~(UARTMODEM_RXRTSE | UARTMODEM_TXCTSE); + + termios->c_cflag &= ~CSTOPB; + + /* parity must be enabled when CS7 to match 8-bits format */ + if ((termios->c_cflag & CSIZE) == CS7) + termios->c_cflag |= PARENB; + + if (termios->c_cflag & PARENB) { + if (termios->c_cflag & CMSPAR) { + cr1 &= ~UARTCR1_PE; + if (termios->c_cflag & PARODD) + cr3 |= UARTCR3_T8; + else + cr3 &= ~UARTCR3_T8; + } else { + cr1 |= UARTCR1_PE; + if ((termios->c_cflag & CSIZE) == CS8) + cr1 |= UARTCR1_M; + if (termios->c_cflag & PARODD) + cr1 |= UARTCR1_PT; + else + cr1 &= ~UARTCR1_PT; + } + } else { + cr1 &= ~UARTCR1_PE; + } + + /* ask the core to calculate the divisor */ + baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16); + + /* + * Need to update the Ring buffer length according to the selected + * baud rate and restart Rx DMA path. + * + * Since timer function acqures sport->port.lock, need to stop before + * acquring same lock because otherwise del_timer_sync() can deadlock. + */ + if (old && sport->lpuart_dma_rx_use) + lpuart_dma_rx_free(&sport->port); + + spin_lock_irqsave(&sport->port.lock, flags); + + sport->port.read_status_mask = 0; + if (termios->c_iflag & INPCK) + sport->port.read_status_mask |= UARTSR1_FE | UARTSR1_PE; + if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) + sport->port.read_status_mask |= UARTSR1_FE; + + /* characters to ignore */ + sport->port.ignore_status_mask = 0; + if (termios->c_iflag & IGNPAR) + sport->port.ignore_status_mask |= UARTSR1_PE; + if (termios->c_iflag & IGNBRK) { + sport->port.ignore_status_mask |= UARTSR1_FE; + /* + * if we're ignoring parity and break indicators, + * ignore overruns too (for real raw support). + */ + if (termios->c_iflag & IGNPAR) + sport->port.ignore_status_mask |= UARTSR1_OR; + } + + /* update the per-port timeout */ + uart_update_timeout(port, termios->c_cflag, baud); + + /* wait transmit engin complete */ + lpuart_wait_bit_set(&sport->port, UARTSR1, UARTSR1_TC); + + /* disable transmit and receive */ + writeb(old_cr2 & ~(UARTCR2_TE | UARTCR2_RE), + sport->port.membase + UARTCR2); + + sbr = sport->port.uartclk / (16 * baud); + brfa = ((sport->port.uartclk - (16 * sbr * baud)) * 2) / baud; + bdh &= ~UARTBDH_SBR_MASK; + bdh |= (sbr >> 8) & 0x1F; + cr4 &= ~UARTCR4_BRFA_MASK; + brfa &= UARTCR4_BRFA_MASK; + writeb(cr4 | brfa, sport->port.membase + UARTCR4); + writeb(bdh, sport->port.membase + UARTBDH); + writeb(sbr & 0xFF, sport->port.membase + UARTBDL); + writeb(cr3, sport->port.membase + UARTCR3); + writeb(cr1, sport->port.membase + UARTCR1); + writeb(modem, sport->port.membase + UARTMODEM); + + /* restore control register */ + writeb(old_cr2, sport->port.membase + UARTCR2); + + if (old && sport->lpuart_dma_rx_use) { + if (!lpuart_start_rx_dma(sport)) + rx_dma_timer_init(sport); + else + sport->lpuart_dma_rx_use = false; + } + + spin_unlock_irqrestore(&sport->port.lock, flags); +} + +static void __lpuart32_serial_setbrg(struct uart_port *port, + unsigned int baudrate, bool use_rx_dma, + bool use_tx_dma) +{ + u32 sbr, osr, baud_diff, tmp_osr, tmp_sbr, tmp_diff, tmp; + u32 clk = port->uartclk; + + /* + * The idea is to use the best OSR (over-sampling rate) possible. + * Note, OSR is typically hard-set to 16 in other LPUART instantiations. + * Loop to find the best OSR value possible, one that generates minimum + * baud_diff iterate through the rest of the supported values of OSR. + * + * Calculation Formula: + * Baud Rate = baud clock / ((OSR+1) × SBR) + */ + baud_diff = baudrate; + osr = 0; + sbr = 0; + + for (tmp_osr = 4; tmp_osr <= 32; tmp_osr++) { + /* calculate the temporary sbr value */ + tmp_sbr = (clk / (baudrate * tmp_osr)); + if (tmp_sbr == 0) + tmp_sbr = 1; + + /* + * calculate the baud rate difference based on the temporary + * osr and sbr values + */ + tmp_diff = clk / (tmp_osr * tmp_sbr) - baudrate; + + /* select best values between sbr and sbr+1 */ + tmp = clk / (tmp_osr * (tmp_sbr + 1)); + if (tmp_diff > (baudrate - tmp)) { + tmp_diff = baudrate - tmp; + tmp_sbr++; + } + + if (tmp_sbr > UARTBAUD_SBR_MASK) + continue; + + if (tmp_diff <= baud_diff) { + baud_diff = tmp_diff; + osr = tmp_osr; + sbr = tmp_sbr; + + if (!baud_diff) + break; + } + } + + /* handle buadrate outside acceptable rate */ + if (baud_diff > ((baudrate / 100) * 3)) + dev_warn(port->dev, + "unacceptable baud rate difference of more than 3%%\n"); + + tmp = lpuart32_read(port, UARTBAUD); + + if ((osr > 3) && (osr < 8)) + tmp |= UARTBAUD_BOTHEDGE; + + tmp &= ~(UARTBAUD_OSR_MASK << UARTBAUD_OSR_SHIFT); + tmp |= ((osr-1) & UARTBAUD_OSR_MASK) << UARTBAUD_OSR_SHIFT; + + tmp &= ~UARTBAUD_SBR_MASK; + tmp |= sbr & UARTBAUD_SBR_MASK; + + if (!use_rx_dma) + tmp &= ~UARTBAUD_RDMAE; + if (!use_tx_dma) + tmp &= ~UARTBAUD_TDMAE; + + lpuart32_write(port, tmp, UARTBAUD); +} + +static void lpuart32_serial_setbrg(struct lpuart_port *sport, + unsigned int baudrate) +{ + __lpuart32_serial_setbrg(&sport->port, baudrate, + sport->lpuart_dma_rx_use, + sport->lpuart_dma_tx_use); +} + + +static void +lpuart32_set_termios(struct uart_port *port, struct ktermios *termios, + struct ktermios *old) +{ + struct lpuart_port *sport = container_of(port, struct lpuart_port, port); + unsigned long flags; + unsigned long ctrl, old_ctrl, modem; + unsigned int baud; + unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8; + + ctrl = old_ctrl = lpuart32_read(&sport->port, UARTCTRL); + modem = lpuart32_read(&sport->port, UARTMODIR); + /* + * only support CS8 and CS7, and for CS7 must enable PE. + * supported mode: + * - (7,e/o,1) + * - (8,n,1) + * - (8,m/s,1) + * - (8,e/o,1) + */ + while ((termios->c_cflag & CSIZE) != CS8 && + (termios->c_cflag & CSIZE) != CS7) { + termios->c_cflag &= ~CSIZE; + termios->c_cflag |= old_csize; + old_csize = CS8; + } + + if ((termios->c_cflag & CSIZE) == CS8 || + (termios->c_cflag & CSIZE) == CS7) + ctrl = old_ctrl & ~UARTCTRL_M; + + if (termios->c_cflag & CMSPAR) { + if ((termios->c_cflag & CSIZE) != CS8) { + termios->c_cflag &= ~CSIZE; + termios->c_cflag |= CS8; + } + ctrl |= UARTCTRL_M; + } + + /* + * When auto RS-485 RTS mode is enabled, + * hardware flow control need to be disabled. + */ + if (sport->port.rs485.flags & SER_RS485_ENABLED) + termios->c_cflag &= ~CRTSCTS; + + if (termios->c_cflag & CRTSCTS) { + modem |= (UARTMODIR_RXRTSE | UARTMODIR_TXCTSE); + } else { + termios->c_cflag &= ~CRTSCTS; + modem &= ~(UARTMODIR_RXRTSE | UARTMODIR_TXCTSE); + } + + if (termios->c_cflag & CSTOPB) + termios->c_cflag &= ~CSTOPB; + + /* parity must be enabled when CS7 to match 8-bits format */ + if ((termios->c_cflag & CSIZE) == CS7) + termios->c_cflag |= PARENB; + + if ((termios->c_cflag & PARENB)) { + if (termios->c_cflag & CMSPAR) { + ctrl &= ~UARTCTRL_PE; + ctrl |= UARTCTRL_M; + } else { + ctrl |= UARTCTRL_PE; + if ((termios->c_cflag & CSIZE) == CS8) + ctrl |= UARTCTRL_M; + if (termios->c_cflag & PARODD) + ctrl |= UARTCTRL_PT; + else + ctrl &= ~UARTCTRL_PT; + } + } else { + ctrl &= ~UARTCTRL_PE; + } + + /* ask the core to calculate the divisor */ + baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 4); + + /* + * Need to update the Ring buffer length according to the selected + * baud rate and restart Rx DMA path. + * + * Since timer function acqures sport->port.lock, need to stop before + * acquring same lock because otherwise del_timer_sync() can deadlock. + */ + if (old && sport->lpuart_dma_rx_use) + lpuart_dma_rx_free(&sport->port); + + spin_lock_irqsave(&sport->port.lock, flags); + + sport->port.read_status_mask = 0; + if (termios->c_iflag & INPCK) + sport->port.read_status_mask |= UARTSTAT_FE | UARTSTAT_PE; + if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) + sport->port.read_status_mask |= UARTSTAT_FE; + + /* characters to ignore */ + sport->port.ignore_status_mask = 0; + if (termios->c_iflag & IGNPAR) + sport->port.ignore_status_mask |= UARTSTAT_PE; + if (termios->c_iflag & IGNBRK) { + sport->port.ignore_status_mask |= UARTSTAT_FE; + /* + * if we're ignoring parity and break indicators, + * ignore overruns too (for real raw support). + */ + if (termios->c_iflag & IGNPAR) + sport->port.ignore_status_mask |= UARTSTAT_OR; + } + + /* update the per-port timeout */ + uart_update_timeout(port, termios->c_cflag, baud); + + /* + * LPUART Transmission Complete Flag may never be set while queuing a break + * character, so skip waiting for transmission complete when UARTCTRL_SBK is + * asserted. + */ + if (!(old_ctrl & UARTCTRL_SBK)) { + lpuart32_write(&sport->port, 0, UARTMODIR); + lpuart32_wait_bit_set(&sport->port, UARTSTAT, UARTSTAT_TC); + } + + /* disable transmit and receive */ + lpuart32_write(&sport->port, old_ctrl & ~(UARTCTRL_TE | UARTCTRL_RE), + UARTCTRL); + + lpuart32_serial_setbrg(sport, baud); + lpuart32_write(&sport->port, modem, UARTMODIR); + lpuart32_write(&sport->port, ctrl, UARTCTRL); + /* restore control register */ + + if (old && sport->lpuart_dma_rx_use) { + if (!lpuart_start_rx_dma(sport)) + rx_dma_timer_init(sport); + else + sport->lpuart_dma_rx_use = false; + } + + spin_unlock_irqrestore(&sport->port.lock, flags); +} + +static const char *lpuart_type(struct uart_port *port) +{ + return "FSL_LPUART"; +} + +static void lpuart_release_port(struct uart_port *port) +{ + /* nothing to do */ +} + +static int lpuart_request_port(struct uart_port *port) +{ + return 0; +} + +/* configure/autoconfigure the port */ +static void lpuart_config_port(struct uart_port *port, int flags) +{ + if (flags & UART_CONFIG_TYPE) + port->type = PORT_LPUART; +} + +static int lpuart_verify_port(struct uart_port *port, struct serial_struct *ser) +{ + int ret = 0; + + if (ser->type != PORT_UNKNOWN && ser->type != PORT_LPUART) + ret = -EINVAL; + if (port->irq != ser->irq) + ret = -EINVAL; + if (ser->io_type != UPIO_MEM) + ret = -EINVAL; + if (port->uartclk / 16 != ser->baud_base) + ret = -EINVAL; + if (port->iobase != ser->port) + ret = -EINVAL; + if (ser->hub6 != 0) + ret = -EINVAL; + return ret; +} + +static const struct uart_ops lpuart_pops = { + .tx_empty = lpuart_tx_empty, + .set_mctrl = lpuart_set_mctrl, + .get_mctrl = lpuart_get_mctrl, + .stop_tx = lpuart_stop_tx, + .start_tx = lpuart_start_tx, + .stop_rx = lpuart_stop_rx, + .break_ctl = lpuart_break_ctl, + .startup = lpuart_startup, + .shutdown = lpuart_shutdown, + .set_termios = lpuart_set_termios, + .type = lpuart_type, + .request_port = lpuart_request_port, + .release_port = lpuart_release_port, + .config_port = lpuart_config_port, + .verify_port = lpuart_verify_port, + .flush_buffer = lpuart_flush_buffer, +#if defined(CONFIG_CONSOLE_POLL) + .poll_init = lpuart_poll_init, + .poll_get_char = lpuart_poll_get_char, + .poll_put_char = lpuart_poll_put_char, +#endif +}; + +static const struct uart_ops lpuart32_pops = { + .tx_empty = lpuart32_tx_empty, + .set_mctrl = lpuart32_set_mctrl, + .get_mctrl = lpuart32_get_mctrl, + .stop_tx = lpuart32_stop_tx, + .start_tx = lpuart32_start_tx, + .stop_rx = lpuart32_stop_rx, + .break_ctl = lpuart32_break_ctl, + .startup = lpuart32_startup, + .shutdown = lpuart32_shutdown, + .set_termios = lpuart32_set_termios, + .type = lpuart_type, + .request_port = lpuart_request_port, + .release_port = lpuart_release_port, + .config_port = lpuart_config_port, + .verify_port = lpuart_verify_port, + .flush_buffer = lpuart_flush_buffer, +#if defined(CONFIG_CONSOLE_POLL) + .poll_init = lpuart32_poll_init, + .poll_get_char = lpuart32_poll_get_char, + .poll_put_char = lpuart32_poll_put_char, +#endif +}; + +static struct lpuart_port *lpuart_ports[UART_NR]; + +#ifdef CONFIG_SERIAL_FSL_LPUART_CONSOLE +static void lpuart_console_putchar(struct uart_port *port, int ch) +{ + lpuart_wait_bit_set(port, UARTSR1, UARTSR1_TDRE); + writeb(ch, port->membase + UARTDR); +} + +static void lpuart32_console_putchar(struct uart_port *port, int ch) +{ + lpuart32_wait_bit_set(port, UARTSTAT, UARTSTAT_TDRE); + lpuart32_write(port, ch, UARTDATA); +} + +static void +lpuart_console_write(struct console *co, const char *s, unsigned int count) +{ + struct lpuart_port *sport = lpuart_ports[co->index]; + unsigned char old_cr2, cr2; + unsigned long flags; + int locked = 1; + + if (sport->port.sysrq || oops_in_progress) + locked = spin_trylock_irqsave(&sport->port.lock, flags); + else + spin_lock_irqsave(&sport->port.lock, flags); + + /* first save CR2 and then disable interrupts */ + cr2 = old_cr2 = readb(sport->port.membase + UARTCR2); + cr2 |= UARTCR2_TE | UARTCR2_RE; + cr2 &= ~(UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_RIE); + writeb(cr2, sport->port.membase + UARTCR2); + + uart_console_write(&sport->port, s, count, lpuart_console_putchar); + + /* wait for transmitter finish complete and restore CR2 */ + lpuart_wait_bit_set(&sport->port, UARTSR1, UARTSR1_TC); + + writeb(old_cr2, sport->port.membase + UARTCR2); + + if (locked) + spin_unlock_irqrestore(&sport->port.lock, flags); +} + +static void +lpuart32_console_write(struct console *co, const char *s, unsigned int count) +{ + struct lpuart_port *sport = lpuart_ports[co->index]; + unsigned long old_cr, cr; + unsigned long flags; + int locked = 1; + + if (sport->port.sysrq || oops_in_progress) + locked = spin_trylock_irqsave(&sport->port.lock, flags); + else + spin_lock_irqsave(&sport->port.lock, flags); + + /* first save CR2 and then disable interrupts */ + cr = old_cr = lpuart32_read(&sport->port, UARTCTRL); + cr |= UARTCTRL_TE | UARTCTRL_RE; + cr &= ~(UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_RIE); + lpuart32_write(&sport->port, cr, UARTCTRL); + + uart_console_write(&sport->port, s, count, lpuart32_console_putchar); + + /* wait for transmitter finish complete and restore CR2 */ + lpuart32_wait_bit_set(&sport->port, UARTSTAT, UARTSTAT_TC); + + lpuart32_write(&sport->port, old_cr, UARTCTRL); + + if (locked) + spin_unlock_irqrestore(&sport->port.lock, flags); +} + +/* + * if the port was already initialised (eg, by a boot loader), + * try to determine the current setup. + */ +static void __init +lpuart_console_get_options(struct lpuart_port *sport, int *baud, + int *parity, int *bits) +{ + unsigned char cr, bdh, bdl, brfa; + unsigned int sbr, uartclk, baud_raw; + + cr = readb(sport->port.membase + UARTCR2); + cr &= UARTCR2_TE | UARTCR2_RE; + if (!cr) + return; + + /* ok, the port was enabled */ + + cr = readb(sport->port.membase + UARTCR1); + + *parity = 'n'; + if (cr & UARTCR1_PE) { + if (cr & UARTCR1_PT) + *parity = 'o'; + else + *parity = 'e'; + } + + if (cr & UARTCR1_M) + *bits = 9; + else + *bits = 8; + + bdh = readb(sport->port.membase + UARTBDH); + bdh &= UARTBDH_SBR_MASK; + bdl = readb(sport->port.membase + UARTBDL); + sbr = bdh; + sbr <<= 8; + sbr |= bdl; + brfa = readb(sport->port.membase + UARTCR4); + brfa &= UARTCR4_BRFA_MASK; + + uartclk = lpuart_get_baud_clk_rate(sport); + /* + * baud = mod_clk/(16*(sbr[13]+(brfa)/32) + */ + baud_raw = uartclk / (16 * (sbr + brfa / 32)); + + if (*baud != baud_raw) + dev_info(sport->port.dev, "Serial: Console lpuart rounded baud rate" + "from %d to %d\n", baud_raw, *baud); +} + +static void __init +lpuart32_console_get_options(struct lpuart_port *sport, int *baud, + int *parity, int *bits) +{ + unsigned long cr, bd; + unsigned int sbr, uartclk, baud_raw; + + cr = lpuart32_read(&sport->port, UARTCTRL); + cr &= UARTCTRL_TE | UARTCTRL_RE; + if (!cr) + return; + + /* ok, the port was enabled */ + + cr = lpuart32_read(&sport->port, UARTCTRL); + + *parity = 'n'; + if (cr & UARTCTRL_PE) { + if (cr & UARTCTRL_PT) + *parity = 'o'; + else + *parity = 'e'; + } + + if (cr & UARTCTRL_M) + *bits = 9; + else + *bits = 8; + + bd = lpuart32_read(&sport->port, UARTBAUD); + bd &= UARTBAUD_SBR_MASK; + if (!bd) + return; + + sbr = bd; + uartclk = lpuart_get_baud_clk_rate(sport); + /* + * baud = mod_clk/(16*(sbr[13]+(brfa)/32) + */ + baud_raw = uartclk / (16 * sbr); + + if (*baud != baud_raw) + dev_info(sport->port.dev, "Serial: Console lpuart rounded baud rate" + "from %d to %d\n", baud_raw, *baud); +} + +static int __init lpuart_console_setup(struct console *co, char *options) +{ + struct lpuart_port *sport; + int baud = 115200; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + + /* + * check whether an invalid uart number has been specified, and + * if so, search for the first available port that does have + * console support. + */ + if (co->index == -1 || co->index >= ARRAY_SIZE(lpuart_ports)) + co->index = 0; + + sport = lpuart_ports[co->index]; + if (sport == NULL) + return -ENODEV; + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + else + if (lpuart_is_32(sport)) + lpuart32_console_get_options(sport, &baud, &parity, &bits); + else + lpuart_console_get_options(sport, &baud, &parity, &bits); + + if (lpuart_is_32(sport)) + lpuart32_setup_watermark(sport); + else + lpuart_setup_watermark(sport); + + return uart_set_options(&sport->port, co, baud, parity, bits, flow); +} + +static struct uart_driver lpuart_reg; +static struct console lpuart_console = { + .name = DEV_NAME, + .write = lpuart_console_write, + .device = uart_console_device, + .setup = lpuart_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &lpuart_reg, +}; + +static struct console lpuart32_console = { + .name = DEV_NAME, + .write = lpuart32_console_write, + .device = uart_console_device, + .setup = lpuart_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &lpuart_reg, +}; + +static void lpuart_early_write(struct console *con, const char *s, unsigned n) +{ + struct earlycon_device *dev = con->data; + + uart_console_write(&dev->port, s, n, lpuart_console_putchar); +} + +static void lpuart32_early_write(struct console *con, const char *s, unsigned n) +{ + struct earlycon_device *dev = con->data; + + uart_console_write(&dev->port, s, n, lpuart32_console_putchar); +} + +static int __init lpuart_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + if (!device->port.membase) + return -ENODEV; + + device->con->write = lpuart_early_write; + return 0; +} + +static int __init lpuart32_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + if (!device->port.membase) + return -ENODEV; + + if (device->port.iotype != UPIO_MEM32) + device->port.iotype = UPIO_MEM32BE; + + device->con->write = lpuart32_early_write; + return 0; +} + +static int __init ls1028a_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + u32 cr; + + if (!device->port.membase) + return -ENODEV; + + device->port.iotype = UPIO_MEM32; + device->con->write = lpuart32_early_write; + + /* set the baudrate */ + if (device->port.uartclk && device->baud) + __lpuart32_serial_setbrg(&device->port, device->baud, + false, false); + + /* enable transmitter */ + cr = lpuart32_read(&device->port, UARTCTRL); + cr |= UARTCTRL_TE; + lpuart32_write(&device->port, cr, UARTCTRL); + + return 0; +} + +static int __init lpuart32_imx_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + if (!device->port.membase) + return -ENODEV; + + device->port.iotype = UPIO_MEM32; + device->port.membase += IMX_REG_OFF; + device->con->write = lpuart32_early_write; + + return 0; +} +OF_EARLYCON_DECLARE(lpuart, "fsl,vf610-lpuart", lpuart_early_console_setup); +OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1021a-lpuart", lpuart32_early_console_setup); +OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1028a-lpuart", ls1028a_early_console_setup); +OF_EARLYCON_DECLARE(lpuart32, "fsl,imx7ulp-lpuart", lpuart32_imx_early_console_setup); +OF_EARLYCON_DECLARE(lpuart32, "fsl,imx8ulp-lpuart", lpuart32_imx_early_console_setup); +OF_EARLYCON_DECLARE(lpuart32, "fsl,imx8qxp-lpuart", lpuart32_imx_early_console_setup); +EARLYCON_DECLARE(lpuart, lpuart_early_console_setup); +EARLYCON_DECLARE(lpuart32, lpuart32_early_console_setup); + +#define LPUART_CONSOLE (&lpuart_console) +#define LPUART32_CONSOLE (&lpuart32_console) +#else +#define LPUART_CONSOLE NULL +#define LPUART32_CONSOLE NULL +#endif + +static struct uart_driver lpuart_reg = { + .owner = THIS_MODULE, + .driver_name = DRIVER_NAME, + .dev_name = DEV_NAME, + .nr = ARRAY_SIZE(lpuart_ports), + .cons = LPUART_CONSOLE, +}; + +static int lpuart_probe(struct platform_device *pdev) +{ + const struct of_device_id *of_id = of_match_device(lpuart_dt_ids, + &pdev->dev); + const struct lpuart_soc_data *sdata = of_id->data; + struct device_node *np = pdev->dev.of_node; + struct lpuart_port *sport; + struct resource *res; + irq_handler_t handler; + int ret; + + sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL); + if (!sport) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + sport->port.membase = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(sport->port.membase)) + return PTR_ERR(sport->port.membase); + + sport->port.membase += sdata->reg_off; + sport->port.mapbase = res->start + sdata->reg_off; + sport->port.dev = &pdev->dev; + sport->port.type = PORT_LPUART; + sport->devtype = sdata->devtype; + ret = platform_get_irq(pdev, 0); + if (ret < 0) + return ret; + sport->port.irq = ret; + sport->port.iotype = sdata->iotype; + if (lpuart_is_32(sport)) + sport->port.ops = &lpuart32_pops; + else + sport->port.ops = &lpuart_pops; + sport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_FSL_LPUART_CONSOLE); + sport->port.flags = UPF_BOOT_AUTOCONF; + + if (lpuart_is_32(sport)) + sport->port.rs485_config = lpuart32_config_rs485; + else + sport->port.rs485_config = lpuart_config_rs485; + + sport->ipg_clk = devm_clk_get(&pdev->dev, "ipg"); + if (IS_ERR(sport->ipg_clk)) { + ret = PTR_ERR(sport->ipg_clk); + dev_err(&pdev->dev, "failed to get uart ipg clk: %d\n", ret); + return ret; + } + + sport->baud_clk = NULL; + if (is_imx8qxp_lpuart(sport)) { + sport->baud_clk = devm_clk_get(&pdev->dev, "baud"); + if (IS_ERR(sport->baud_clk)) { + ret = PTR_ERR(sport->baud_clk); + dev_err(&pdev->dev, "failed to get uart baud clk: %d\n", ret); + return ret; + } + } + + ret = of_alias_get_id(np, "serial"); + if (ret < 0) { + dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret); + return ret; + } + if (ret >= ARRAY_SIZE(lpuart_ports)) { + dev_err(&pdev->dev, "serial%d out of range\n", ret); + return -EINVAL; + } + sport->port.line = ret; + + ret = lpuart_enable_clks(sport); + if (ret) + return ret; + sport->port.uartclk = lpuart_get_baud_clk_rate(sport); + + lpuart_ports[sport->port.line] = sport; + + platform_set_drvdata(pdev, &sport->port); + + if (lpuart_is_32(sport)) { + lpuart_reg.cons = LPUART32_CONSOLE; + handler = lpuart32_int; + } else { + lpuart_reg.cons = LPUART_CONSOLE; + handler = lpuart_int; + } + + ret = uart_get_rs485_mode(&sport->port); + if (ret) + goto failed_get_rs485; + + if (sport->port.rs485.flags & SER_RS485_RX_DURING_TX) + dev_err(&pdev->dev, "driver doesn't support RX during TX\n"); + + if (sport->port.rs485.delay_rts_before_send || + sport->port.rs485.delay_rts_after_send) + dev_err(&pdev->dev, "driver doesn't support RTS delays\n"); + + ret = uart_add_one_port(&lpuart_reg, &sport->port); + if (ret) + goto failed_attach_port; + + ret = devm_request_irq(&pdev->dev, sport->port.irq, handler, 0, + DRIVER_NAME, sport); + if (ret) + goto failed_irq_request; + + return 0; + +failed_irq_request: + uart_remove_one_port(&lpuart_reg, &sport->port); +failed_get_rs485: +failed_attach_port: + lpuart_disable_clks(sport); + return ret; +} + +static int lpuart_remove(struct platform_device *pdev) +{ + struct lpuart_port *sport = platform_get_drvdata(pdev); + + uart_remove_one_port(&lpuart_reg, &sport->port); + + lpuart_disable_clks(sport); + + if (sport->dma_tx_chan) + dma_release_channel(sport->dma_tx_chan); + + if (sport->dma_rx_chan) + dma_release_channel(sport->dma_rx_chan); + + return 0; +} + +static int __maybe_unused lpuart_suspend(struct device *dev) +{ + struct lpuart_port *sport = dev_get_drvdata(dev); + unsigned long temp; + bool irq_wake; + + if (lpuart_is_32(sport)) { + /* disable Rx/Tx and interrupts */ + temp = lpuart32_read(&sport->port, UARTCTRL); + temp &= ~(UARTCTRL_TE | UARTCTRL_TIE | UARTCTRL_TCIE); + lpuart32_write(&sport->port, temp, UARTCTRL); + } else { + /* disable Rx/Tx and interrupts */ + temp = readb(sport->port.membase + UARTCR2); + temp &= ~(UARTCR2_TE | UARTCR2_TIE | UARTCR2_TCIE); + writeb(temp, sport->port.membase + UARTCR2); + } + + uart_suspend_port(&lpuart_reg, &sport->port); + + /* uart_suspend_port() might set wakeup flag */ + irq_wake = irqd_is_wakeup_set(irq_get_irq_data(sport->port.irq)); + + if (sport->lpuart_dma_rx_use) { + /* + * EDMA driver during suspend will forcefully release any + * non-idle DMA channels. If port wakeup is enabled or if port + * is console port or 'no_console_suspend' is set the Rx DMA + * cannot resume as expected, hence gracefully release the + * Rx DMA path before suspend and start Rx DMA path on resume. + */ + if (irq_wake) { + lpuart_dma_rx_free(&sport->port); + } + + /* Disable Rx DMA to use UART port as wakeup source */ + if (lpuart_is_32(sport)) { + temp = lpuart32_read(&sport->port, UARTBAUD); + lpuart32_write(&sport->port, temp & ~UARTBAUD_RDMAE, + UARTBAUD); + } else { + writeb(readb(sport->port.membase + UARTCR5) & + ~UARTCR5_RDMAS, sport->port.membase + UARTCR5); + } + } + + if (sport->lpuart_dma_tx_use) { + sport->dma_tx_in_progress = false; + dmaengine_terminate_all(sport->dma_tx_chan); + } + + if (sport->port.suspended && !irq_wake) + lpuart_disable_clks(sport); + + return 0; +} + +static int __maybe_unused lpuart_resume(struct device *dev) +{ + struct lpuart_port *sport = dev_get_drvdata(dev); + bool irq_wake = irqd_is_wakeup_set(irq_get_irq_data(sport->port.irq)); + + if (sport->port.suspended && !irq_wake) + lpuart_enable_clks(sport); + + if (lpuart_is_32(sport)) + lpuart32_setup_watermark_enable(sport); + else + lpuart_setup_watermark_enable(sport); + + if (sport->lpuart_dma_rx_use) { + if (irq_wake) { + if (!lpuart_start_rx_dma(sport)) + rx_dma_timer_init(sport); + else + sport->lpuart_dma_rx_use = false; + } + } + + lpuart_tx_dma_startup(sport); + + if (lpuart_is_32(sport)) + lpuart32_configure(sport); + + uart_resume_port(&lpuart_reg, &sport->port); + + return 0; +} + +static SIMPLE_DEV_PM_OPS(lpuart_pm_ops, lpuart_suspend, lpuart_resume); + +static struct platform_driver lpuart_driver = { + .probe = lpuart_probe, + .remove = lpuart_remove, + .driver = { + .name = "fsl-lpuart", + .of_match_table = lpuart_dt_ids, + .pm = &lpuart_pm_ops, + }, +}; + +static int __init lpuart_serial_init(void) +{ + int ret = uart_register_driver(&lpuart_reg); + + if (ret) + return ret; + + ret = platform_driver_register(&lpuart_driver); + if (ret) + uart_unregister_driver(&lpuart_reg); + + return ret; +} + +static void __exit lpuart_serial_exit(void) +{ + platform_driver_unregister(&lpuart_driver); + uart_unregister_driver(&lpuart_reg); +} + +module_init(lpuart_serial_init); +module_exit(lpuart_serial_exit); + +MODULE_DESCRIPTION("Freescale lpuart serial port driver"); +MODULE_LICENSE("GPL v2"); |