diff options
Diffstat (limited to 'drivers/tty/serial/imx.c')
| -rw-r--r-- | drivers/tty/serial/imx.c | 137 |
1 files changed, 117 insertions, 20 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 90974d338f3c..17f70e4bee43 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -230,6 +230,8 @@ struct imx_port { unsigned int saved_reg[10]; bool context_saved; + bool last_putchar_was_newline; + enum imx_tx_state tx_state; struct hrtimer trigger_start_tx; struct hrtimer trigger_stop_tx; @@ -370,6 +372,7 @@ static void imx_uart_soft_reset(struct imx_port *sport) sport->idle_counter = 0; } +/* called with port.lock taken and irqs off */ static void imx_uart_disable_loopback_rs485(struct imx_port *sport) { unsigned int uts; @@ -470,6 +473,7 @@ static void imx_uart_stop_tx(struct uart_port *port) } } +/* called with port.lock taken and irqs off */ static void imx_uart_stop_rx_with_loopback_ctrl(struct uart_port *port, bool loopback) { struct imx_port *sport = to_imx_port(port); @@ -818,6 +822,8 @@ static irqreturn_t imx_uart_txint(int irq, void *dev_id) * issuing soft reset to the UART (just stop/start of RX does not help). Note * that what we do here is sending isolated start bit about 2.4 times shorter * than it is to be on UART configured baud rate. + * + * Called with port.lock taken and irqs off. */ static void imx_uart_check_flood(struct imx_port *sport, u32 usr2) { @@ -853,6 +859,7 @@ static void imx_uart_check_flood(struct imx_port *sport, u32 usr2) } } +/* called with port.lock taken and irqs off */ static irqreturn_t __imx_uart_rxint(int irq, void *dev_id) { struct imx_port *sport = dev_id; @@ -931,6 +938,7 @@ static void imx_uart_clear_rx_errors(struct imx_port *sport); /* * We have a modem side uart, so the meanings of RTS and CTS are inverted. */ +/* called with port.lock taken and irqs off */ static unsigned int imx_uart_get_hwmctrl(struct imx_port *sport) { unsigned int tmp = TIOCM_DSR; @@ -953,6 +961,8 @@ static unsigned int imx_uart_get_hwmctrl(struct imx_port *sport) /* * Handle any change of modem status signal since we were last called. + * + * Called with port.lock taken and irqs off. */ static void imx_uart_mctrl_check(struct imx_port *sport) { @@ -1292,6 +1302,7 @@ static int imx_uart_start_rx_dma(struct imx_port *sport) return 0; } +/* called with port.lock taken and irqs off */ static void imx_uart_clear_rx_errors(struct imx_port *sport) { struct tty_port *port = &sport->port.state->port; @@ -1422,6 +1433,7 @@ err: return ret; } +/* called with port.lock taken and irqs off */ static void imx_uart_enable_dma(struct imx_port *sport) { u32 ucr1; @@ -2069,26 +2081,34 @@ static void imx_uart_console_putchar(struct uart_port *port, unsigned char ch) barrier(); imx_uart_writel(sport, ch, URTX0); + + sport->last_putchar_was_newline = (ch == '\n'); } -/* - * Interrupts are disabled on entering - */ -static void -imx_uart_console_write(struct console *co, const char *s, unsigned int count) +static void imx_uart_console_device_lock(struct console *co, unsigned long *flags) +{ + struct uart_port *up = &imx_uart_ports[co->index]->port; + + return __uart_port_lock_irqsave(up, flags); +} + +static void imx_uart_console_device_unlock(struct console *co, unsigned long flags) +{ + struct uart_port *up = &imx_uart_ports[co->index]->port; + + return __uart_port_unlock_irqrestore(up, flags); +} + +static void imx_uart_console_write_atomic(struct console *co, + struct nbcon_write_context *wctxt) { struct imx_port *sport = imx_uart_ports[co->index]; + struct uart_port *port = &sport->port; struct imx_port_ucrs old_ucr; - unsigned long flags; unsigned int ucr1, usr2; - int locked = 1; - if (sport->port.sysrq) - locked = 0; - else if (oops_in_progress) - locked = uart_port_trylock_irqsave(&sport->port, &flags); - else - uart_port_lock_irqsave(&sport->port, &flags); + if (!nbcon_enter_unsafe(wctxt)) + return; /* * First, save UCR1/2/3 and then disable interrupts @@ -2102,10 +2122,12 @@ imx_uart_console_write(struct console *co, const char *s, unsigned int count) ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN); imx_uart_writel(sport, ucr1, UCR1); - imx_uart_writel(sport, old_ucr.ucr2 | UCR2_TXEN, UCR2); - uart_console_write(&sport->port, s, count, imx_uart_console_putchar); + if (!sport->last_putchar_was_newline) + uart_console_write(port, "\n", 1, imx_uart_console_putchar); + uart_console_write(port, wctxt->outbuf, wctxt->len, + imx_uart_console_putchar); /* * Finally, wait for transmitter to become empty @@ -2115,8 +2137,73 @@ imx_uart_console_write(struct console *co, const char *s, unsigned int count) 0, USEC_PER_SEC, false, sport, USR2); imx_uart_ucrs_restore(sport, &old_ucr); - if (locked) - uart_port_unlock_irqrestore(&sport->port, flags); + nbcon_exit_unsafe(wctxt); +} + +static void imx_uart_console_write_thread(struct console *co, + struct nbcon_write_context *wctxt) +{ + struct imx_port *sport = imx_uart_ports[co->index]; + struct uart_port *port = &sport->port; + struct imx_port_ucrs old_ucr; + unsigned int ucr1, usr2; + + if (!nbcon_enter_unsafe(wctxt)) + return; + + /* + * First, save UCR1/2/3 and then disable interrupts + */ + imx_uart_ucrs_save(sport, &old_ucr); + ucr1 = old_ucr.ucr1; + + if (imx_uart_is_imx1(sport)) + ucr1 |= IMX1_UCR1_UARTCLKEN; + ucr1 |= UCR1_UARTEN; + ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN); + + imx_uart_writel(sport, ucr1, UCR1); + imx_uart_writel(sport, old_ucr.ucr2 | UCR2_TXEN, UCR2); + + if (nbcon_exit_unsafe(wctxt)) { + int len = READ_ONCE(wctxt->len); + int i; + + /* + * Write out the message. Toggle unsafe for each byte in order + * to give another (higher priority) context the opportunity + * for a friendly takeover. If such a takeover occurs, this + * context must reacquire ownership in order to perform final + * actions (such as re-enabling the interrupts). + * + * IMPORTANT: wctxt->outbuf and wctxt->len are no longer valid + * after a reacquire so writing the message must be + * aborted. + */ + for (i = 0; i < len; i++) { + if (!nbcon_enter_unsafe(wctxt)) + break; + + uart_console_write(port, wctxt->outbuf + i, 1, + imx_uart_console_putchar); + + if (!nbcon_exit_unsafe(wctxt)) + break; + } + } + + while (!nbcon_enter_unsafe(wctxt)) + nbcon_reacquire_nobuf(wctxt); + + /* + * Finally, wait for transmitter to become empty + * and restore UCR1/2/3 + */ + read_poll_timeout(imx_uart_readl, usr2, usr2 & USR2_TXDC, + 0, USEC_PER_SEC, false, sport, USR2); + imx_uart_ucrs_restore(sport, &old_ucr); + + nbcon_exit_unsafe(wctxt); } /* @@ -2208,6 +2295,8 @@ imx_uart_console_setup(struct console *co, char *options) if (retval) goto error_console; + sport->last_putchar_was_newline = true; + if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); else @@ -2244,11 +2333,14 @@ imx_uart_console_exit(struct console *co) static struct uart_driver imx_uart_uart_driver; static struct console imx_uart_console = { .name = DEV_NAME, - .write = imx_uart_console_write, + .write_atomic = imx_uart_console_write_atomic, + .write_thread = imx_uart_console_write_thread, + .device_lock = imx_uart_console_device_lock, + .device_unlock = imx_uart_console_device_unlock, + .flags = CON_PRINTBUFFER | CON_NBCON, .device = uart_console_device, .setup = imx_uart_console_setup, .exit = imx_uart_console_exit, - .flags = CON_PRINTBUFFER, .index = -1, .data = &imx_uart_uart_driver, }; @@ -2595,10 +2687,13 @@ static void imx_uart_save_context(struct imx_port *sport) uart_port_unlock_irqrestore(&sport->port, flags); } +/* called with irq off */ static void imx_uart_enable_wakeup(struct imx_port *sport, bool on) { u32 ucr3; + uart_port_lock(&sport->port); + ucr3 = imx_uart_readl(sport, UCR3); if (on) { imx_uart_writel(sport, USR1_AWAKE, USR1); @@ -2618,6 +2713,8 @@ static void imx_uart_enable_wakeup(struct imx_port *sport, bool on) } imx_uart_writel(sport, ucr1, UCR1); } + + uart_port_unlock(&sport->port); } static int imx_uart_suspend_noirq(struct device *dev) @@ -2717,7 +2814,7 @@ static const struct dev_pm_ops imx_uart_pm_ops = { static struct platform_driver imx_uart_platform_driver = { .probe = imx_uart_probe, - .remove_new = imx_uart_remove, + .remove = imx_uart_remove, .driver = { .name = "imx-uart", |