diff options
Diffstat (limited to 'drivers/tty/serial/st-asc.c')
| -rw-r--r-- | drivers/tty/serial/st-asc.c | 1010 |
1 files changed, 1010 insertions, 0 deletions
diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c new file mode 100644 index 000000000..97d36f870 --- /dev/null +++ b/drivers/tty/serial/st-asc.c @@ -0,0 +1,1010 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * st-asc.c: ST Asynchronous serial controller (ASC) driver + * + * Copyright (C) 2003-2013 STMicroelectronics (R&D) Limited + */ + +#include <linux/module.h> +#include <linux/serial.h> +#include <linux/console.h> +#include <linux/sysrq.h> +#include <linux/pinctrl/consumer.h> +#include <linux/platform_device.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/delay.h> +#include <linux/spinlock.h> +#include <linux/pm_runtime.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/serial_core.h> +#include <linux/clk.h> +#include <linux/gpio/consumer.h> + +#define DRIVER_NAME "st-asc" +#define ASC_SERIAL_NAME "ttyAS" +#define ASC_FIFO_SIZE 16 +#define ASC_MAX_PORTS 8 + +/* Pinctrl states */ +#define DEFAULT 0 +#define NO_HW_FLOWCTRL 1 + +struct asc_port { + struct uart_port port; + struct gpio_desc *rts; + struct clk *clk; + struct pinctrl *pinctrl; + struct pinctrl_state *states[2]; + unsigned int hw_flow_control:1; + unsigned int force_m1:1; +}; + +static struct asc_port asc_ports[ASC_MAX_PORTS]; +static struct uart_driver asc_uart_driver; + +/*---- UART Register definitions ------------------------------*/ + +/* Register offsets */ + +#define ASC_BAUDRATE 0x00 +#define ASC_TXBUF 0x04 +#define ASC_RXBUF 0x08 +#define ASC_CTL 0x0C +#define ASC_INTEN 0x10 +#define ASC_STA 0x14 +#define ASC_GUARDTIME 0x18 +#define ASC_TIMEOUT 0x1C +#define ASC_TXRESET 0x20 +#define ASC_RXRESET 0x24 +#define ASC_RETRIES 0x28 + +/* ASC_RXBUF */ +#define ASC_RXBUF_PE 0x100 +#define ASC_RXBUF_FE 0x200 +/** + * Some of status comes from higher bits of the character and some come from + * the status register. Combining both of them in to single status using dummy + * bits. + */ +#define ASC_RXBUF_DUMMY_RX 0x10000 +#define ASC_RXBUF_DUMMY_BE 0x20000 +#define ASC_RXBUF_DUMMY_OE 0x40000 + +/* ASC_CTL */ + +#define ASC_CTL_MODE_MSK 0x0007 +#define ASC_CTL_MODE_8BIT 0x0001 +#define ASC_CTL_MODE_7BIT_PAR 0x0003 +#define ASC_CTL_MODE_9BIT 0x0004 +#define ASC_CTL_MODE_8BIT_WKUP 0x0005 +#define ASC_CTL_MODE_8BIT_PAR 0x0007 +#define ASC_CTL_STOP_MSK 0x0018 +#define ASC_CTL_STOP_HALFBIT 0x0000 +#define ASC_CTL_STOP_1BIT 0x0008 +#define ASC_CTL_STOP_1_HALFBIT 0x0010 +#define ASC_CTL_STOP_2BIT 0x0018 +#define ASC_CTL_PARITYODD 0x0020 +#define ASC_CTL_LOOPBACK 0x0040 +#define ASC_CTL_RUN 0x0080 +#define ASC_CTL_RXENABLE 0x0100 +#define ASC_CTL_SCENABLE 0x0200 +#define ASC_CTL_FIFOENABLE 0x0400 +#define ASC_CTL_CTSENABLE 0x0800 +#define ASC_CTL_BAUDMODE 0x1000 + +/* ASC_GUARDTIME */ + +#define ASC_GUARDTIME_MSK 0x00FF + +/* ASC_INTEN */ + +#define ASC_INTEN_RBE 0x0001 +#define ASC_INTEN_TE 0x0002 +#define ASC_INTEN_THE 0x0004 +#define ASC_INTEN_PE 0x0008 +#define ASC_INTEN_FE 0x0010 +#define ASC_INTEN_OE 0x0020 +#define ASC_INTEN_TNE 0x0040 +#define ASC_INTEN_TOI 0x0080 +#define ASC_INTEN_RHF 0x0100 + +/* ASC_RETRIES */ + +#define ASC_RETRIES_MSK 0x00FF + +/* ASC_RXBUF */ + +#define ASC_RXBUF_MSK 0x03FF + +/* ASC_STA */ + +#define ASC_STA_RBF 0x0001 +#define ASC_STA_TE 0x0002 +#define ASC_STA_THE 0x0004 +#define ASC_STA_PE 0x0008 +#define ASC_STA_FE 0x0010 +#define ASC_STA_OE 0x0020 +#define ASC_STA_TNE 0x0040 +#define ASC_STA_TOI 0x0080 +#define ASC_STA_RHF 0x0100 +#define ASC_STA_TF 0x0200 +#define ASC_STA_NKD 0x0400 + +/* ASC_TIMEOUT */ + +#define ASC_TIMEOUT_MSK 0x00FF + +/* ASC_TXBUF */ + +#define ASC_TXBUF_MSK 0x01FF + +/*---- Inline function definitions ---------------------------*/ + +static inline struct asc_port *to_asc_port(struct uart_port *port) +{ + return container_of(port, struct asc_port, port); +} + +static inline u32 asc_in(struct uart_port *port, u32 offset) +{ +#ifdef readl_relaxed + return readl_relaxed(port->membase + offset); +#else + return readl(port->membase + offset); +#endif +} + +static inline void asc_out(struct uart_port *port, u32 offset, u32 value) +{ +#ifdef writel_relaxed + writel_relaxed(value, port->membase + offset); +#else + writel(value, port->membase + offset); +#endif +} + +/* + * Some simple utility functions to enable and disable interrupts. + * Note that these need to be called with interrupts disabled. + */ +static inline void asc_disable_tx_interrupts(struct uart_port *port) +{ + u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_THE; + asc_out(port, ASC_INTEN, intenable); + (void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */ +} + +static inline void asc_enable_tx_interrupts(struct uart_port *port) +{ + u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_THE; + asc_out(port, ASC_INTEN, intenable); +} + +static inline void asc_disable_rx_interrupts(struct uart_port *port) +{ + u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_RBE; + asc_out(port, ASC_INTEN, intenable); + (void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */ +} + +static inline void asc_enable_rx_interrupts(struct uart_port *port) +{ + u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_RBE; + asc_out(port, ASC_INTEN, intenable); +} + +static inline u32 asc_txfifo_is_empty(struct uart_port *port) +{ + return asc_in(port, ASC_STA) & ASC_STA_TE; +} + +static inline u32 asc_txfifo_is_half_empty(struct uart_port *port) +{ + return asc_in(port, ASC_STA) & ASC_STA_THE; +} + +static inline const char *asc_port_name(struct uart_port *port) +{ + return to_platform_device(port->dev)->name; +} + +/*----------------------------------------------------------------------*/ + +/* + * This section contains code to support the use of the ASC as a + * generic serial port. + */ + +static inline unsigned asc_hw_txroom(struct uart_port *port) +{ + u32 status = asc_in(port, ASC_STA); + + if (status & ASC_STA_THE) + return port->fifosize / 2; + else if (!(status & ASC_STA_TF)) + return 1; + + return 0; +} + +/* + * Start transmitting chars. + * This is called from both interrupt and task level. + * Either way interrupts are disabled. + */ +static void asc_transmit_chars(struct uart_port *port) +{ + struct circ_buf *xmit = &port->state->xmit; + int txroom; + unsigned char c; + + txroom = asc_hw_txroom(port); + + if ((txroom != 0) && port->x_char) { + c = port->x_char; + port->x_char = 0; + asc_out(port, ASC_TXBUF, c); + port->icount.tx++; + txroom = asc_hw_txroom(port); + } + + if (uart_tx_stopped(port)) { + /* + * We should try and stop the hardware here, but I + * don't think the ASC has any way to do that. + */ + asc_disable_tx_interrupts(port); + return; + } + + if (uart_circ_empty(xmit)) { + asc_disable_tx_interrupts(port); + return; + } + + if (txroom == 0) + return; + + do { + c = xmit->buf[xmit->tail]; + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + asc_out(port, ASC_TXBUF, c); + port->icount.tx++; + txroom--; + } while ((txroom > 0) && (!uart_circ_empty(xmit))); + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); + + if (uart_circ_empty(xmit)) + asc_disable_tx_interrupts(port); +} + +static void asc_receive_chars(struct uart_port *port) +{ + struct tty_port *tport = &port->state->port; + unsigned long status, mode; + unsigned long c = 0; + char flag; + bool ignore_pe = false; + + /* + * Datasheet states: If the MODE field selects an 8-bit frame then + * this [parity error] bit is undefined. Software should ignore this + * bit when reading 8-bit frames. + */ + mode = asc_in(port, ASC_CTL) & ASC_CTL_MODE_MSK; + if (mode == ASC_CTL_MODE_8BIT || mode == ASC_CTL_MODE_8BIT_PAR) + ignore_pe = true; + + if (irqd_is_wakeup_set(irq_get_irq_data(port->irq))) + pm_wakeup_event(tport->tty->dev, 0); + + while ((status = asc_in(port, ASC_STA)) & ASC_STA_RBF) { + c = asc_in(port, ASC_RXBUF) | ASC_RXBUF_DUMMY_RX; + flag = TTY_NORMAL; + port->icount.rx++; + + if (status & ASC_STA_OE || c & ASC_RXBUF_FE || + (c & ASC_RXBUF_PE && !ignore_pe)) { + + if (c & ASC_RXBUF_FE) { + if (c == (ASC_RXBUF_FE | ASC_RXBUF_DUMMY_RX)) { + port->icount.brk++; + if (uart_handle_break(port)) + continue; + c |= ASC_RXBUF_DUMMY_BE; + } else { + port->icount.frame++; + } + } else if (c & ASC_RXBUF_PE) { + port->icount.parity++; + } + /* + * Reading any data from the RX FIFO clears the + * overflow error condition. + */ + if (status & ASC_STA_OE) { + port->icount.overrun++; + c |= ASC_RXBUF_DUMMY_OE; + } + + c &= port->read_status_mask; + + if (c & ASC_RXBUF_DUMMY_BE) + flag = TTY_BREAK; + else if (c & ASC_RXBUF_PE) + flag = TTY_PARITY; + else if (c & ASC_RXBUF_FE) + flag = TTY_FRAME; + } + + if (uart_handle_sysrq_char(port, c & 0xff)) + continue; + + uart_insert_char(port, c, ASC_RXBUF_DUMMY_OE, c & 0xff, flag); + } + + /* Tell the rest of the system the news. New characters! */ + tty_flip_buffer_push(tport); +} + +static irqreturn_t asc_interrupt(int irq, void *ptr) +{ + struct uart_port *port = ptr; + u32 status; + + spin_lock(&port->lock); + + status = asc_in(port, ASC_STA); + + if (status & ASC_STA_RBF) { + /* Receive FIFO not empty */ + asc_receive_chars(port); + } + + if ((status & ASC_STA_THE) && + (asc_in(port, ASC_INTEN) & ASC_INTEN_THE)) { + /* Transmitter FIFO at least half empty */ + asc_transmit_chars(port); + } + + spin_unlock(&port->lock); + + return IRQ_HANDLED; +} + +/*----------------------------------------------------------------------*/ + +/* + * UART Functions + */ + +static unsigned int asc_tx_empty(struct uart_port *port) +{ + return asc_txfifo_is_empty(port) ? TIOCSER_TEMT : 0; +} + +static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + struct asc_port *ascport = to_asc_port(port); + + /* + * This routine is used for seting signals of: DTR, DCD, CTS and RTS. + * We use ASC's hardware for CTS/RTS when hardware flow-control is + * enabled, however if the RTS line is required for another purpose, + * commonly controlled using HUP from userspace, then we need to toggle + * it manually, using GPIO. + * + * Some boards also have DTR and DCD implemented using PIO pins, code to + * do this should be hooked in here. + */ + + if (!ascport->rts) + return; + + /* If HW flow-control is enabled, we can't fiddle with the RTS line */ + if (asc_in(port, ASC_CTL) & ASC_CTL_CTSENABLE) + return; + + gpiod_set_value(ascport->rts, mctrl & TIOCM_RTS); +} + +static unsigned int asc_get_mctrl(struct uart_port *port) +{ + /* + * This routine is used for geting signals of: DTR, DCD, DSR, RI, + * and CTS/RTS + */ + return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; +} + +/* There are probably characters waiting to be transmitted. */ +static void asc_start_tx(struct uart_port *port) +{ + struct circ_buf *xmit = &port->state->xmit; + + if (!uart_circ_empty(xmit)) + asc_enable_tx_interrupts(port); +} + +/* Transmit stop */ +static void asc_stop_tx(struct uart_port *port) +{ + asc_disable_tx_interrupts(port); +} + +/* Receive stop */ +static void asc_stop_rx(struct uart_port *port) +{ + asc_disable_rx_interrupts(port); +} + +/* Handle breaks - ignored by us */ +static void asc_break_ctl(struct uart_port *port, int break_state) +{ + /* Nothing here yet .. */ +} + +/* + * Enable port for reception. + */ +static int asc_startup(struct uart_port *port) +{ + if (request_irq(port->irq, asc_interrupt, 0, + asc_port_name(port), port)) { + dev_err(port->dev, "cannot allocate irq.\n"); + return -ENODEV; + } + + asc_transmit_chars(port); + asc_enable_rx_interrupts(port); + + return 0; +} + +static void asc_shutdown(struct uart_port *port) +{ + asc_disable_tx_interrupts(port); + asc_disable_rx_interrupts(port); + free_irq(port->irq, port); +} + +static void asc_pm(struct uart_port *port, unsigned int state, + unsigned int oldstate) +{ + struct asc_port *ascport = to_asc_port(port); + unsigned long flags = 0; + u32 ctl; + + switch (state) { + case UART_PM_STATE_ON: + clk_prepare_enable(ascport->clk); + break; + case UART_PM_STATE_OFF: + /* + * Disable the ASC baud rate generator, which is as close as + * we can come to turning it off. Note this is not called with + * the port spinlock held. + */ + spin_lock_irqsave(&port->lock, flags); + ctl = asc_in(port, ASC_CTL) & ~ASC_CTL_RUN; + asc_out(port, ASC_CTL, ctl); + spin_unlock_irqrestore(&port->lock, flags); + clk_disable_unprepare(ascport->clk); + break; + } +} + +static void asc_set_termios(struct uart_port *port, struct ktermios *termios, + struct ktermios *old) +{ + struct asc_port *ascport = to_asc_port(port); + struct gpio_desc *gpiod; + unsigned int baud; + u32 ctrl_val; + tcflag_t cflag; + unsigned long flags; + + /* Update termios to reflect hardware capabilities */ + termios->c_cflag &= ~(CMSPAR | + (ascport->hw_flow_control ? 0 : CRTSCTS)); + + port->uartclk = clk_get_rate(ascport->clk); + + baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); + cflag = termios->c_cflag; + + spin_lock_irqsave(&port->lock, flags); + + /* read control register */ + ctrl_val = asc_in(port, ASC_CTL); + + /* stop serial port and reset value */ + asc_out(port, ASC_CTL, (ctrl_val & ~ASC_CTL_RUN)); + ctrl_val = ASC_CTL_RXENABLE | ASC_CTL_FIFOENABLE; + + /* reset fifo rx & tx */ + asc_out(port, ASC_TXRESET, 1); + asc_out(port, ASC_RXRESET, 1); + + /* set character length */ + if ((cflag & CSIZE) == CS7) { + ctrl_val |= ASC_CTL_MODE_7BIT_PAR; + cflag |= PARENB; + } else { + ctrl_val |= (cflag & PARENB) ? ASC_CTL_MODE_8BIT_PAR : + ASC_CTL_MODE_8BIT; + cflag &= ~CSIZE; + cflag |= CS8; + } + termios->c_cflag = cflag; + + /* set stop bit */ + ctrl_val |= (cflag & CSTOPB) ? ASC_CTL_STOP_2BIT : ASC_CTL_STOP_1BIT; + + /* odd parity */ + if (cflag & PARODD) + ctrl_val |= ASC_CTL_PARITYODD; + + /* hardware flow control */ + if ((cflag & CRTSCTS)) { + ctrl_val |= ASC_CTL_CTSENABLE; + + /* If flow-control selected, stop handling RTS manually */ + if (ascport->rts) { + devm_gpiod_put(port->dev, ascport->rts); + ascport->rts = NULL; + + pinctrl_select_state(ascport->pinctrl, + ascport->states[DEFAULT]); + } + } else { + /* If flow-control disabled, it's safe to handle RTS manually */ + if (!ascport->rts && ascport->states[NO_HW_FLOWCTRL]) { + pinctrl_select_state(ascport->pinctrl, + ascport->states[NO_HW_FLOWCTRL]); + + gpiod = devm_gpiod_get(port->dev, "rts", GPIOD_OUT_LOW); + if (!IS_ERR(gpiod)) { + gpiod_set_consumer_name(gpiod, + port->dev->of_node->name); + ascport->rts = gpiod; + } + } + } + + if ((baud < 19200) && !ascport->force_m1) { + asc_out(port, ASC_BAUDRATE, (port->uartclk / (16 * baud))); + } else { + /* + * MODE 1: recommended for high bit rates (above 19.2K) + * + * baudrate * 16 * 2^16 + * ASCBaudRate = ------------------------ + * inputclock + * + * To keep maths inside 64bits, we divide inputclock by 16. + */ + u64 dividend = (u64)baud * (1 << 16); + + do_div(dividend, port->uartclk / 16); + asc_out(port, ASC_BAUDRATE, dividend); + ctrl_val |= ASC_CTL_BAUDMODE; + } + + uart_update_timeout(port, cflag, baud); + + ascport->port.read_status_mask = ASC_RXBUF_DUMMY_OE; + if (termios->c_iflag & INPCK) + ascport->port.read_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE; + if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) + ascport->port.read_status_mask |= ASC_RXBUF_DUMMY_BE; + + /* + * Characters to ignore + */ + ascport->port.ignore_status_mask = 0; + if (termios->c_iflag & IGNPAR) + ascport->port.ignore_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE; + if (termios->c_iflag & IGNBRK) { + ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_BE; + /* + * If we're ignoring parity and break indicators, + * ignore overruns too (for real raw support). + */ + if (termios->c_iflag & IGNPAR) + ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_OE; + } + + /* + * Ignore all characters if CREAD is not set. + */ + if (!(termios->c_cflag & CREAD)) + ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_RX; + + /* Set the timeout */ + asc_out(port, ASC_TIMEOUT, 20); + + /* write final value and enable port */ + asc_out(port, ASC_CTL, (ctrl_val | ASC_CTL_RUN)); + + spin_unlock_irqrestore(&port->lock, flags); +} + +static const char *asc_type(struct uart_port *port) +{ + return (port->type == PORT_ASC) ? DRIVER_NAME : NULL; +} + +static void asc_release_port(struct uart_port *port) +{ +} + +static int asc_request_port(struct uart_port *port) +{ + return 0; +} + +/* + * Called when the port is opened, and UPF_BOOT_AUTOCONF flag is set + * Set type field if successful + */ +static void asc_config_port(struct uart_port *port, int flags) +{ + if ((flags & UART_CONFIG_TYPE)) + port->type = PORT_ASC; +} + +static int +asc_verify_port(struct uart_port *port, struct serial_struct *ser) +{ + /* No user changeable parameters */ + return -EINVAL; +} + +#ifdef CONFIG_CONSOLE_POLL +/* + * Console polling routines for writing and reading from the uart while + * in an interrupt or debug context (i.e. kgdb). + */ + +static int asc_get_poll_char(struct uart_port *port) +{ + if (!(asc_in(port, ASC_STA) & ASC_STA_RBF)) + return NO_POLL_CHAR; + + return asc_in(port, ASC_RXBUF); +} + +static void asc_put_poll_char(struct uart_port *port, unsigned char c) +{ + while (!asc_txfifo_is_half_empty(port)) + cpu_relax(); + asc_out(port, ASC_TXBUF, c); +} + +#endif /* CONFIG_CONSOLE_POLL */ + +/*---------------------------------------------------------------------*/ + +static const struct uart_ops asc_uart_ops = { + .tx_empty = asc_tx_empty, + .set_mctrl = asc_set_mctrl, + .get_mctrl = asc_get_mctrl, + .start_tx = asc_start_tx, + .stop_tx = asc_stop_tx, + .stop_rx = asc_stop_rx, + .break_ctl = asc_break_ctl, + .startup = asc_startup, + .shutdown = asc_shutdown, + .set_termios = asc_set_termios, + .type = asc_type, + .release_port = asc_release_port, + .request_port = asc_request_port, + .config_port = asc_config_port, + .verify_port = asc_verify_port, + .pm = asc_pm, +#ifdef CONFIG_CONSOLE_POLL + .poll_get_char = asc_get_poll_char, + .poll_put_char = asc_put_poll_char, +#endif /* CONFIG_CONSOLE_POLL */ +}; + +static int asc_init_port(struct asc_port *ascport, + struct platform_device *pdev) +{ + struct uart_port *port = &ascport->port; + struct resource *res; + int ret; + + port->iotype = UPIO_MEM; + port->flags = UPF_BOOT_AUTOCONF; + port->ops = &asc_uart_ops; + port->fifosize = ASC_FIFO_SIZE; + port->dev = &pdev->dev; + port->irq = platform_get_irq(pdev, 0); + port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_ST_ASC_CONSOLE); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + port->membase = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(port->membase)) + return PTR_ERR(port->membase); + port->mapbase = res->start; + + spin_lock_init(&port->lock); + + ascport->clk = devm_clk_get(&pdev->dev, NULL); + + if (WARN_ON(IS_ERR(ascport->clk))) + return -EINVAL; + /* ensure that clk rate is correct by enabling the clk */ + clk_prepare_enable(ascport->clk); + ascport->port.uartclk = clk_get_rate(ascport->clk); + WARN_ON(ascport->port.uartclk == 0); + clk_disable_unprepare(ascport->clk); + + ascport->pinctrl = devm_pinctrl_get(&pdev->dev); + if (IS_ERR(ascport->pinctrl)) { + ret = PTR_ERR(ascport->pinctrl); + dev_err(&pdev->dev, "Failed to get Pinctrl: %d\n", ret); + return ret; + } + + ascport->states[DEFAULT] = + pinctrl_lookup_state(ascport->pinctrl, "default"); + if (IS_ERR(ascport->states[DEFAULT])) { + ret = PTR_ERR(ascport->states[DEFAULT]); + dev_err(&pdev->dev, + "Failed to look up Pinctrl state 'default': %d\n", ret); + return ret; + } + + /* "no-hw-flowctrl" state is optional */ + ascport->states[NO_HW_FLOWCTRL] = + pinctrl_lookup_state(ascport->pinctrl, "no-hw-flowctrl"); + if (IS_ERR(ascport->states[NO_HW_FLOWCTRL])) + ascport->states[NO_HW_FLOWCTRL] = NULL; + + return 0; +} + +static struct asc_port *asc_of_get_asc_port(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + int id; + + if (!np) + return NULL; + + id = of_alias_get_id(np, "serial"); + if (id < 0) + id = of_alias_get_id(np, ASC_SERIAL_NAME); + + if (id < 0) + id = 0; + + if (WARN_ON(id >= ASC_MAX_PORTS)) + return NULL; + + asc_ports[id].hw_flow_control = of_property_read_bool(np, + "uart-has-rtscts"); + asc_ports[id].force_m1 = of_property_read_bool(np, "st,force_m1"); + asc_ports[id].port.line = id; + asc_ports[id].rts = NULL; + + return &asc_ports[id]; +} + +#ifdef CONFIG_OF +static const struct of_device_id asc_match[] = { + { .compatible = "st,asc", }, + {}, +}; + +MODULE_DEVICE_TABLE(of, asc_match); +#endif + +static int asc_serial_probe(struct platform_device *pdev) +{ + int ret; + struct asc_port *ascport; + + ascport = asc_of_get_asc_port(pdev); + if (!ascport) + return -ENODEV; + + ret = asc_init_port(ascport, pdev); + if (ret) + return ret; + + ret = uart_add_one_port(&asc_uart_driver, &ascport->port); + if (ret) + return ret; + + platform_set_drvdata(pdev, &ascport->port); + + return 0; +} + +static int asc_serial_remove(struct platform_device *pdev) +{ + struct uart_port *port = platform_get_drvdata(pdev); + + return uart_remove_one_port(&asc_uart_driver, port); +} + +#ifdef CONFIG_PM_SLEEP +static int asc_serial_suspend(struct device *dev) +{ + struct uart_port *port = dev_get_drvdata(dev); + + return uart_suspend_port(&asc_uart_driver, port); +} + +static int asc_serial_resume(struct device *dev) +{ + struct uart_port *port = dev_get_drvdata(dev); + + return uart_resume_port(&asc_uart_driver, port); +} + +#endif /* CONFIG_PM_SLEEP */ + +/*----------------------------------------------------------------------*/ + +#ifdef CONFIG_SERIAL_ST_ASC_CONSOLE +static void asc_console_putchar(struct uart_port *port, int ch) +{ + unsigned int timeout = 1000000; + + /* Wait for upto 1 second in case flow control is stopping us. */ + while (--timeout && !asc_txfifo_is_half_empty(port)) + udelay(1); + + asc_out(port, ASC_TXBUF, ch); +} + +/* + * Print a string to the serial port trying not to disturb + * any possible real use of the port... + */ + +static void asc_console_write(struct console *co, const char *s, unsigned count) +{ + struct uart_port *port = &asc_ports[co->index].port; + unsigned long flags; + unsigned long timeout = 1000000; + int locked = 1; + u32 intenable; + + if (port->sysrq) + locked = 0; /* asc_interrupt has already claimed the lock */ + else if (oops_in_progress) + locked = spin_trylock_irqsave(&port->lock, flags); + else + spin_lock_irqsave(&port->lock, flags); + + /* + * Disable interrupts so we don't get the IRQ line bouncing + * up and down while interrupts are disabled. + */ + intenable = asc_in(port, ASC_INTEN); + asc_out(port, ASC_INTEN, 0); + (void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */ + + uart_console_write(port, s, count, asc_console_putchar); + + while (--timeout && !asc_txfifo_is_empty(port)) + udelay(1); + + asc_out(port, ASC_INTEN, intenable); + + if (locked) + spin_unlock_irqrestore(&port->lock, flags); +} + +static int asc_console_setup(struct console *co, char *options) +{ + struct asc_port *ascport; + int baud = 115200; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + + if (co->index >= ASC_MAX_PORTS) + return -ENODEV; + + ascport = &asc_ports[co->index]; + + /* + * This driver does not support early console initialization + * (use ARM early printk support instead), so we only expect + * this to be called during the uart port registration when the + * driver gets probed and the port should be mapped at that point. + */ + if (ascport->port.mapbase == 0 || ascport->port.membase == NULL) + return -ENXIO; + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + + return uart_set_options(&ascport->port, co, baud, parity, bits, flow); +} + +static struct console asc_console = { + .name = ASC_SERIAL_NAME, + .device = uart_console_device, + .write = asc_console_write, + .setup = asc_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &asc_uart_driver, +}; + +#define ASC_SERIAL_CONSOLE (&asc_console) + +#else +#define ASC_SERIAL_CONSOLE NULL +#endif /* CONFIG_SERIAL_ST_ASC_CONSOLE */ + +static struct uart_driver asc_uart_driver = { + .owner = THIS_MODULE, + .driver_name = DRIVER_NAME, + .dev_name = ASC_SERIAL_NAME, + .major = 0, + .minor = 0, + .nr = ASC_MAX_PORTS, + .cons = ASC_SERIAL_CONSOLE, +}; + +static const struct dev_pm_ops asc_serial_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(asc_serial_suspend, asc_serial_resume) +}; + +static struct platform_driver asc_serial_driver = { + .probe = asc_serial_probe, + .remove = asc_serial_remove, + .driver = { + .name = DRIVER_NAME, + .pm = &asc_serial_pm_ops, + .of_match_table = of_match_ptr(asc_match), + }, +}; + +static int __init asc_init(void) +{ + int ret; + static const char banner[] __initconst = + KERN_INFO "STMicroelectronics ASC driver initialized\n"; + + printk(banner); + + ret = uart_register_driver(&asc_uart_driver); + if (ret) + return ret; + + ret = platform_driver_register(&asc_serial_driver); + if (ret) + uart_unregister_driver(&asc_uart_driver); + + return ret; +} + +static void __exit asc_exit(void) +{ + platform_driver_unregister(&asc_serial_driver); + uart_unregister_driver(&asc_uart_driver); +} + +module_init(asc_init); +module_exit(asc_exit); + +MODULE_ALIAS("platform:" DRIVER_NAME); +MODULE_AUTHOR("STMicroelectronics (R&D) Limited"); +MODULE_DESCRIPTION("STMicroelectronics ASC serial port driver"); +MODULE_LICENSE("GPL"); |