serial: mxs-auart: add interrupts for modem control lines (f9e42397) · Commits · jan.koester / Linux

drivers/tty/serial/mxs-auart.c

+172 −2

Original line number	Diff line number	Diff line
		@@ -42,7 +42,10 @@

		#include <asm/cacheflush.h>

		#include <linux/gpio.h>
		#include <linux/gpio/consumer.h>
		#include <linux/err.h>
		#include <linux/irq.h>
		#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);