[PATCH 3/4] serial: mxs-auart: add interrupts for modem control lines
Janusz Użycki
j.uzycki at elproma.com.pl
Fri Oct 24 08:36:53 PDT 2014
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 at elproma.com.pl>
>> ---
>> 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 at gmail.com>
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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