From f9e42397d79b6e810437ba1130b0b4b594f5e56c Mon Sep 17 00:00:00 2001 From: Janusz Uzycki Date: Fri, 10 Oct 2014 18:53:26 +0200 Subject: [PATCH] serial: mxs-auart: add interrupts for modem control lines Handle CTS/DSR/RI/DCD GPIO interrupts in mxs-auart. Signed-off-by: Janusz Uzycki Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/mxs-auart.c | 174 ++++++++++++++++++++++++++++++++- 1 file changed, 172 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c index 5922cb435a87..088f1e17b33e 100644 --- a/drivers/tty/serial/mxs-auart.c +++ b/drivers/tty/serial/mxs-auart.c @@ -42,7 +42,10 @@ #include +#include +#include #include +#include #include "serial_mctrl_gpio.h" #define MXS_AUART_PORTS 5 @@ -146,6 +149,7 @@ struct mxs_auart_port { #define MXS_AUART_DMA_RX_READY 3 /* bit 3 */ #define MXS_AUART_RTSCTS 4 /* bit 4 */ unsigned long flags; + unsigned int mctrl_prev; enum mxs_auart_type devtype; unsigned int irq; @@ -163,6 +167,8 @@ struct mxs_auart_port { void *rx_dma_buf; struct mctrl_gpios *gpios; + int gpio_irq[UART_GPIO_MAX]; + bool ms_irq_enabled; }; static struct platform_device_id mxs_auart_devtype[] = { @@ -427,6 +433,29 @@ static void mxs_auart_set_mctrl(struct uart_port *u, unsigned mctrl) mctrl_gpio_set(s->gpios, mctrl); } +#define MCTRL_ANY_DELTA (TIOCM_RI | TIOCM_DSR | TIOCM_CD | TIOCM_CTS) +static u32 mxs_auart_modem_status(struct mxs_auart_port *s, u32 mctrl) +{ + u32 mctrl_diff; + + mctrl_diff = mctrl ^ s->mctrl_prev; + s->mctrl_prev = mctrl; + if (mctrl_diff & MCTRL_ANY_DELTA && s->ms_irq_enabled && + s->port.state != NULL) { + if (mctrl_diff & TIOCM_RI) + s->port.icount.rng++; + if (mctrl_diff & TIOCM_DSR) + s->port.icount.dsr++; + if (mctrl_diff & TIOCM_CD) + uart_handle_dcd_change(&s->port, mctrl & TIOCM_CD); + if (mctrl_diff & TIOCM_CTS) + uart_handle_cts_change(&s->port, mctrl & TIOCM_CTS); + + wake_up_interruptible(&s->port.state->port.delta_msr_wait); + } + return mctrl; +} + static u32 mxs_auart_get_mctrl(struct uart_port *u) { struct mxs_auart_port *s = to_auart_port(u); @@ -439,6 +468,64 @@ static u32 mxs_auart_get_mctrl(struct uart_port *u) return mctrl_gpio_get(s->gpios, &mctrl); } +/* + * Enable modem status interrupts + */ +static void mxs_auart_enable_ms(struct uart_port *port) +{ + struct mxs_auart_port *s = to_auart_port(port); + + /* + * Interrupt should not be enabled twice + */ + if (s->ms_irq_enabled) + return; + + s->ms_irq_enabled = true; + + if (s->gpio_irq[UART_GPIO_CTS] >= 0) + enable_irq(s->gpio_irq[UART_GPIO_CTS]); + /* TODO: enable AUART_INTR_CTSMIEN otherwise */ + + if (s->gpio_irq[UART_GPIO_DSR] >= 0) + enable_irq(s->gpio_irq[UART_GPIO_DSR]); + + if (s->gpio_irq[UART_GPIO_RI] >= 0) + enable_irq(s->gpio_irq[UART_GPIO_RI]); + + if (s->gpio_irq[UART_GPIO_DCD] >= 0) + enable_irq(s->gpio_irq[UART_GPIO_DCD]); +} + +/* + * Disable modem status interrupts + */ +static void mxs_auart_disable_ms(struct uart_port *port) +{ + struct mxs_auart_port *s = to_auart_port(port); + + /* + * Interrupt should not be disabled twice + */ + if (!s->ms_irq_enabled) + return; + + s->ms_irq_enabled = false; + + if (s->gpio_irq[UART_GPIO_CTS] >= 0) + disable_irq(s->gpio_irq[UART_GPIO_CTS]); + /* TODO: disable AUART_INTR_CTSMIEN otherwise */ + + if (s->gpio_irq[UART_GPIO_DSR] >= 0) + disable_irq(s->gpio_irq[UART_GPIO_DSR]); + + if (s->gpio_irq[UART_GPIO_RI] >= 0) + disable_irq(s->gpio_irq[UART_GPIO_RI]); + + if (s->gpio_irq[UART_GPIO_DCD] >= 0) + disable_irq(s->gpio_irq[UART_GPIO_DCD]); +} + static int mxs_auart_dma_prep_rx(struct mxs_auart_port *s); static void dma_rx_callback(void *arg) { @@ -689,6 +776,12 @@ static void mxs_auart_settermios(struct uart_port *u, dev_err(s->dev, "We can not start up the DMA.\n"); } } + + /* CTS flow-control and modem-status interrupts */ + if (UART_ENABLE_MS(u, termios->c_cflag)) + mxs_auart_enable_ms(u); + else + mxs_auart_disable_ms(u); } static irqreturn_t mxs_auart_irq_handle(int irq, void *context) @@ -706,8 +799,18 @@ static irqreturn_t mxs_auart_irq_handle(int irq, void *context) | AUART_INTR_CTSMIS), s->port.membase + AUART_INTR_CLR); + /* + * Dealing with GPIO interrupt + */ + if (irq == s->gpio_irq[UART_GPIO_CTS] || + irq == s->gpio_irq[UART_GPIO_DCD] || + irq == s->gpio_irq[UART_GPIO_DSR] || + irq == s->gpio_irq[UART_GPIO_RI]) + mxs_auart_modem_status(s, + mctrl_gpio_get(s->gpios, &s->mctrl_prev)); + if (istat & AUART_INTR_CTSMIS) { - if (CTS_AT_AUART()) + if (CTS_AT_AUART() && s->ms_irq_enabled) uart_handle_cts_change(&s->port, stat & AUART_STAT_CTS); writel(AUART_INTR_CTSMIS, @@ -770,6 +873,10 @@ static int mxs_auart_startup(struct uart_port *u) */ writel(AUART_LINECTRL_FEN, u->membase + AUART_LINECTRL_SET); + /* get initial status of modem lines */ + mctrl_gpio_get(s->gpios, &s->mctrl_prev); + + s->ms_irq_enabled = false; return 0; } @@ -777,6 +884,8 @@ static void mxs_auart_shutdown(struct uart_port *u) { struct mxs_auart_port *s = to_auart_port(u); + mxs_auart_disable_ms(u); + if (auart_dma_enabled(s)) mxs_auart_dma_exit(s); @@ -833,6 +942,7 @@ static struct uart_ops mxs_auart_ops = { .start_tx = mxs_auart_start_tx, .stop_tx = mxs_auart_stop_tx, .stop_rx = mxs_auart_stop_rx, + .enable_ms = mxs_auart_enable_ms, .break_ctl = mxs_auart_break_ctl, .set_mctrl = mxs_auart_set_mctrl, .get_mctrl = mxs_auart_get_mctrl, @@ -1035,6 +1145,9 @@ static int serial_mxs_probe_dt(struct mxs_auart_port *s, static bool mxs_auart_init_gpios(struct mxs_auart_port *s, struct device *dev) { + enum mctrl_gpio_idx i; + struct gpio_desc *gpiod; + s->gpios = mctrl_gpio_init(dev, 0); if (IS_ERR_OR_NULL(s->gpios)) return false; @@ -1047,9 +1160,54 @@ static bool mxs_auart_init_gpios(struct mxs_auart_port *s, struct device *dev) clear_bit(MXS_AUART_RTSCTS, &s->flags); } + for (i = 0; i < UART_GPIO_MAX; i++) { + gpiod = mctrl_gpio_to_gpiod(s->gpios, i); + if (gpiod && (gpiod_get_direction(gpiod) == GPIOF_DIR_IN)) + s->gpio_irq[i] = gpiod_to_irq(gpiod); + else + s->gpio_irq[i] = -EINVAL; + } + return true; } +static void mxs_auart_free_gpio_irq(struct mxs_auart_port *s) +{ + enum mctrl_gpio_idx i; + + for (i = 0; i < UART_GPIO_MAX; i++) + if (s->gpio_irq[i] >= 0) + free_irq(s->gpio_irq[i], s); +} + +static int mxs_auart_request_gpio_irq(struct mxs_auart_port *s) +{ + int *irq = s->gpio_irq; + enum mctrl_gpio_idx i; + int err = 0; + + for (i = 0; (i < UART_GPIO_MAX) && !err; i++) { + if (irq[i] < 0) + continue; + + irq_set_status_flags(irq[i], IRQ_NOAUTOEN); + err = request_irq(irq[i], mxs_auart_irq_handle, + IRQ_TYPE_EDGE_BOTH, dev_name(s->dev), s); + if (err) + dev_err(s->dev, "%s - Can't get %d irq\n", + __func__, irq[i]); + } + + /* + * If something went wrong, rollback. + */ + while (err && (--i >= 0)) + if (irq[i] >= 0) + free_irq(irq[i], s); + + return err; +} + static int mxs_auart_probe(struct platform_device *pdev) { const struct of_device_id *of_id = @@ -1097,6 +1255,8 @@ static int mxs_auart_probe(struct platform_device *pdev) s->port.type = PORT_IMX; s->port.dev = s->dev = &pdev->dev; + s->mctrl_prev = 0; + s->irq = platform_get_irq(pdev, 0); s->port.irq = s->irq; ret = request_irq(s->irq, mxs_auart_irq_handle, 0, dev_name(&pdev->dev), s); @@ -1109,13 +1269,20 @@ static int mxs_auart_probe(struct platform_device *pdev) dev_err(&pdev->dev, "Failed to initialize GPIOs. The serial port may not work as expected\n"); + /* + * Get the GPIO lines IRQ + */ + ret = mxs_auart_request_gpio_irq(s); + if (ret) + goto out_free_irq; + auart_port[s->port.line] = s; mxs_auart_reset(&s->port); ret = uart_add_one_port(&auart_driver, &s->port); if (ret) - goto out_free_irq; + goto out_free_gpio_irq; version = readl(s->port.membase + AUART_VERSION); dev_info(&pdev->dev, "Found APPUART %d.%d.%d\n", @@ -1124,6 +1291,8 @@ static int mxs_auart_probe(struct platform_device *pdev) return 0; +out_free_gpio_irq: + mxs_auart_free_gpio_irq(s); out_free_irq: auart_port[pdev->id] = NULL; free_irq(s->irq, s); @@ -1143,6 +1312,7 @@ static int mxs_auart_remove(struct platform_device *pdev) auart_port[pdev->id] = NULL; + mxs_auart_free_gpio_irq(s); clk_put(s->clk); free_irq(s->irq, s); kfree(s); -- 2.39.5