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>
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