Re: [PATCH 3/4] serial: mxs-auart: add interrupts for modem control lines

[Janusz Użycki <j.uzycki@xxxxxxxxxxxxxx>]

W dniu 2014-10-24 o 17:32, Richard Genoud pisze:
> On 27/09/2014 11:46, Janusz Uzycki wrote:
> > Handle CTS/DSR/RI/DCD GPIO interrupts in mxs-auart.
> >
> > Signed-off-by: Janusz Uzycki <j.uzycki@xxxxxxxxxxxxxx>
> > ---
> >   drivers/tty/serial/mxs-auart.c | 176 ++++++++++++++++++++++++++-
> >   1 file changed, 174 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
> > index fdfa8a9..ab127a2 100644
> > --- a/drivers/tty/serial/mxs-auart.c
> > +++ b/drivers/tty/serial/mxs-auart.c
> > @@ -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);
> > @@ -444,6 +473,64 @@ 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)
> >   {
> > @@ -692,6 +779,12 @@ 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)
> > @@ -709,9 +802,20 @@ 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 (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(s->gpios,
> > -						UART_GPIO_CTS)))
> > +							UART_GPIO_CTS))
> > +						&& s->ms_irq_enabled)
> >   			uart_handle_cts_change(&s->port,
> >   					stat & AUART_STAT_CTS);
> >   		writel(AUART_INTR_CTSMIS,
> > @@ -774,6 +878,10 @@ 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;
> >   }
> >   
> > @@ -781,6 +889,8 @@ 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);
> >   
> > @@ -837,6 +947,7 @@ 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,
> > @@ -1039,12 +1150,61 @@ static int serial_mxs_probe_dt(struct mxs_auart_port *s,
> >   
> >   static int 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 -1;
> > +
> > +	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 0;
> >   }
> >   
> > +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 =
> > @@ -1092,6 +1252,8 @@ 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);
> > @@ -1105,13 +1267,20 @@ static int mxs_auart_probe(struct platform_device *pdev)
> >   		dev_err(&pdev->dev, "%s",
> >   			"Failed to initialize GPIOs. The serial port may not work as expected");
> >   
> > +	/*
> > +	 * 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",
> > @@ -1120,6 +1289,8 @@ 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);
> > @@ -1139,6 +1310,7 @@ 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);
> Seems also ok.
> Janusz, will you provide a patch to complete {en,dis}able_ms functions
> for non-gpio ?
>
> Reviewed-by: Richard Genoud <richard.genoud@xxxxxxxxx>

Thanks for comments.
I added "TODO" to not forget
but I can't add non-gpio crt/rts on the moment (no my case).

best regards
Janusz

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