[RFC PATCH v2 1/4] tty: serial_mctrl_gpio: Add irqs helpers for input lines
Uwe Kleine-König
u.kleine-koenig at pengutronix.de
Tue Jan 13 00:03:56 PST 2015
On Sat, Jan 10, 2015 at 03:32:43PM +0100, Janusz Uzycki wrote:
> A driver using mctrl_gpio called gpiod_get_direction() to check if
> gpio is input line. However .get_direction callback is not available
> for all platforms. The patch allows to avoid the function.
> The patch introduces the following helpers:
> - mctrl_gpio_request_irqs
> - mctrl_gpio_free_irqs
> - mctrl_gpio_enable_ms
> - mctrl_gpio_disable_ms
> They allow to:
> - simplify drivers which use mctrl_gpio
> - hide irq table in mctrl_gpio
> - use default irq handler for gpios
> - better separate code for gpio modem lines from uart's code
> In addition mctrl_gpio_init() has been renamed to mctrl_gpio_init_dt()
Note that this breaks the drivers that are already using
mctrl_gpio_init. This is fixed up in the follow up patches, but still
you break bisection.
> to focus DT usage. Also mctrl_gpio_init_dt() initializes irq table for
> gpios now and passes struct uart_port into struct mctrl_gpios.
> This resulted in changed mctrl_gpio_init_dt() parameter.
> It also requires port->dev is set before the function is called.
>
> There were also fixed:
> - irq = 0 means invalid/unused (-EINVAL no more used)
> - mctrl_gpio_request_irqs() doesn't use negative enum value
> if request_irq() failed. It just calls mctrl_gpio_free_irqs().
>
> The mctrl_gpio_is_gpio() inline function is under discussion
> and likely it can replace exported mctrl_gpio_to_gpiod() function.
>
> IRQ_NOAUTOEN setting and request_irq() order was not commented
> but it looks right according to other drivers.
I suggest to add a comment for that. Something like:
/*
* XXX: This is not undone in the error path. To be fixed
* properly this needs to be set atomically together with
* request_irq.
*/
> Signed-off-by: Janusz Uzycki <j.uzycki at elproma.com.pl>
There is no binding documentation for mctrl. This should be fixed, too.
> ---
>
> The patch requires to update the drivers which use mctrl_gpio:
> - atmel_serial
> - mxs-auart
> - clps711x
>
> Changes since RFC v1:
> - patch renamed from:
> ("serial: mctrl-gpio: Add irqs helpers for input lines")
> to:
> ("tty: serial_mctrl_gpio: Add irqs helpers for input lines")
> - mctrl_gpio_request_irqs: changed mctrl_gpio_free_irqs() and
> dev_err() order to make debug easier
> - added patches for atmel_serial and clps711x serial drivers
>
> The patch applies to next (3.19.0-rc2) and was tested with mxs-auart
> using kernel 3.14 and 3.18. It wasn't tested on the next (only compiled).
>
> The patchset delivers patches for mxs-auart, atmel_serial and clps711x.
> atmel_serial and clps711x were not tested - only compile tests were done.
>
> ---
> drivers/tty/serial/serial_mctrl_gpio.c | 109 ++++++++++++++++++++++++++++++++-
> drivers/tty/serial/serial_mctrl_gpio.h | 59 +++++++++++++++++-
> 2 files changed, 163 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/tty/serial/serial_mctrl_gpio.c b/drivers/tty/serial/serial_mctrl_gpio.c
> index a38596c..215b15c 100644
> --- a/drivers/tty/serial/serial_mctrl_gpio.c
> +++ b/drivers/tty/serial/serial_mctrl_gpio.c
> @@ -19,11 +19,15 @@
> #include <linux/device.h>
> #include <linux/gpio/consumer.h>
> #include <linux/termios.h>
> +#include <linux/irq.h>
>
> #include "serial_mctrl_gpio.h"
>
> struct mctrl_gpios {
> + struct uart_port *port;
> struct gpio_desc *gpio[UART_GPIO_MAX];
> + int irq[UART_GPIO_MAX];
> + unsigned int mctrl_prev;
> };
>
> static const struct {
> @@ -72,6 +76,12 @@ struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
> }
> EXPORT_SYMBOL_GPL(mctrl_gpio_to_gpiod);
>
> +inline
> +bool mctrl_gpio_is_gpio(struct mctrl_gpios *gpios, enum mctrl_gpio_idx gidx)
> +{
> + return !IS_ERR_OR_NULL(gpios->gpio[gidx]);
> +}
> +
> unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
> {
> enum mctrl_gpio_idx i;
> @@ -96,8 +106,9 @@ unsigned int mctrl_gpio_get(struct mctrl_gpios *gpios, unsigned int *mctrl)
> }
> EXPORT_SYMBOL_GPL(mctrl_gpio_get);
>
> -struct mctrl_gpios *mctrl_gpio_init(struct device *dev, unsigned int idx)
> +struct mctrl_gpios *mctrl_gpio_init_dt(struct uart_port *port, unsigned int idx)
> {
> + struct device *dev = port->dev;
> struct mctrl_gpios *gpios;
> enum mctrl_gpio_idx i;
> int err;
> @@ -106,6 +117,7 @@ struct mctrl_gpios *mctrl_gpio_init(struct device *dev, unsigned int idx)
> if (!gpios)
> return ERR_PTR(-ENOMEM);
>
> + gpios->port = port;
> for (i = 0; i < UART_GPIO_MAX; i++) {
> gpios->gpio[i] = devm_gpiod_get_index(dev,
> mctrl_gpios_desc[i].name,
> @@ -128,11 +140,13 @@ struct mctrl_gpios *mctrl_gpio_init(struct device *dev, unsigned int idx)
> devm_gpiod_put(dev, gpios->gpio[i]);
> gpios->gpio[i] = NULL;
> }
> + if (gpios->gpio[i] && !mctrl_gpios_desc[i].dir_out)
> + gpios->irq[i] = gpiod_to_irq(gpios->gpio[i]);
> }
>
> return gpios;
> }
> -EXPORT_SYMBOL_GPL(mctrl_gpio_init);
> +EXPORT_SYMBOL_GPL(mctrl_gpio_init_dt);
>
> void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
> {
> @@ -147,3 +161,94 @@ void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
> devm_kfree(dev, gpios);
> }
> EXPORT_SYMBOL_GPL(mctrl_gpio_free);
> +
> +/*
> + * Dealing with GPIO interrupt
> + */
> +#define MCTRL_ANY_DELTA (TIOCM_RI | TIOCM_DSR | TIOCM_CD | TIOCM_CTS)
> +static irqreturn_t mctrl_gpio_irq_handle(int irq, void *context)
> +{
> + struct mctrl_gpios *gpios = context;
> + struct uart_port *port = gpios->port;
> + u32 mctrl = gpios->mctrl_prev;
> + u32 mctrl_diff;
> +
> + mctrl_gpio_get(gpios, &mctrl);
> +
> + mctrl_diff = mctrl ^ gpios->mctrl_prev;
> + gpios->mctrl_prev = mctrl;
> + if (mctrl_diff & MCTRL_ANY_DELTA && port->state != NULL) {
> + if (mctrl_diff & TIOCM_RI)
> + port->icount.rng++;
> + if (mctrl_diff & TIOCM_DSR)
> + port->icount.dsr++;
> + if (mctrl_diff & TIOCM_CD)
> + uart_handle_dcd_change(port, mctrl & TIOCM_CD);
> + if (mctrl_diff & TIOCM_CTS)
> + uart_handle_cts_change(port, mctrl & TIOCM_CTS);
> +
> + wake_up_interruptible(&port->state->port.delta_msr_wait);
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +int mctrl_gpio_request_irqs(struct mctrl_gpios *gpios)
> +{
> + struct uart_port *port = gpios->port;
> + int *irq = gpios->irq;
> + enum mctrl_gpio_idx i;
> + int err = 0;
> +
> + for (i = 0; i < UART_GPIO_MAX; i++) {
> + if (irq[i] <= 0)
> + continue;
> +
> + irq_set_status_flags(irq[i], IRQ_NOAUTOEN);
> + err = request_irq(irq[i], mctrl_gpio_irq_handle,
> + IRQ_TYPE_EDGE_BOTH,
> + dev_name(port->dev), gpios);
> + if (err) {
> + dev_err(port->dev, "%s: Can't get %d irq\n",
> + __func__, irq[i]);
> + mctrl_gpio_free_irqs(gpios);
> + break;
> + }
> + }
> +
> + return err;
> +}
> +EXPORT_SYMBOL_GPL(mctrl_gpio_request_irqs);
> +
> +void mctrl_gpio_free_irqs(struct mctrl_gpios *gpios)
> +{
> + enum mctrl_gpio_idx i;
> +
> + for (i = 0; i < UART_GPIO_MAX; i++)
> + if (gpios->irq[i] > 0)
> + free_irq(gpios->irq[i], gpios);
> +}
> +EXPORT_SYMBOL_GPL(mctrl_gpio_free_irqs);
> +
> +void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
> +{
> + enum mctrl_gpio_idx i;
> +
> + /* get initial status of modem lines GPIOs */
> + mctrl_gpio_get(gpios, &gpios->mctrl_prev);
> +
> + for (i = 0; i < UART_GPIO_MAX; i++)
> + if (gpios->irq[i] > 0)
> + enable_irq(gpios->irq[i]);
> +}
> +EXPORT_SYMBOL_GPL(mctrl_gpio_enable_ms);
> +
> +void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
> +{
> + enum mctrl_gpio_idx i;
> +
> + for (i = 0; i < UART_GPIO_MAX; i++)
> + if (gpios->irq[i] > 0)
> + disable_irq(gpios->irq[i]);
> +}
> +EXPORT_SYMBOL_GPL(mctrl_gpio_disable_ms);
> diff --git a/drivers/tty/serial/serial_mctrl_gpio.h b/drivers/tty/serial/serial_mctrl_gpio.h
> index 400ba04..13ba3f4 100644
> --- a/drivers/tty/serial/serial_mctrl_gpio.h
> +++ b/drivers/tty/serial/serial_mctrl_gpio.h
> @@ -21,6 +21,7 @@
> #include <linux/err.h>
> #include <linux/device.h>
> #include <linux/gpio/consumer.h>
> +#include <linux/serial_core.h>
>
> enum mctrl_gpio_idx {
> UART_GPIO_CTS,
> @@ -40,6 +41,13 @@ enum mctrl_gpio_idx {
> */
> struct mctrl_gpios;
>
> +/*
> + * Return true if gidx is GPIO line, otherwise false.
> + * It assumes that gpios is allocated and not NULL.
> + */
> +inline
> +bool mctrl_gpio_is_gpio(struct mctrl_gpios *gpios, enum mctrl_gpio_idx gidx);
> +
> #ifdef CONFIG_GPIOLIB
>
> /*
> @@ -60,12 +68,13 @@ struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
> enum mctrl_gpio_idx gidx);
>
> /*
> - * Request and set direction of modem control lines GPIOs.
> + * Request and set direction of modem control lines GPIOs. DT is used.
> + * Initialize irq table for GPIOs.
> * devm_* functions are used, so there's no need to call mctrl_gpio_free().
> * Returns a pointer to the allocated mctrl structure if ok, -ENOMEM on
> * allocation error.
> */
> -struct mctrl_gpios *mctrl_gpio_init(struct device *dev, unsigned int idx);
> +struct mctrl_gpios *mctrl_gpio_init_dt(struct uart_port *port, unsigned int idx);
>
> /*
> * Free the mctrl_gpios structure.
> @@ -74,6 +83,28 @@ struct mctrl_gpios *mctrl_gpio_init(struct device *dev, unsigned int idx);
> */
> void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios);
>
> +/*
> + * Request irqs for input lines GPIOs. The irqs are set disabled
> + * and triggered on both edges.
> + * Returns zero if OK, otherwise an error code.
> + */
> +int mctrl_gpio_request_irqs(struct mctrl_gpios *gpios);
> +
> +/*
> + * Free irqs for input lines GPIOs.
> + */
> +void mctrl_gpio_free_irqs(struct mctrl_gpios *gpios);
> +
> +/*
> + * Disable modem status interrupts assigned to GPIOs
> + */
> +void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios);
> +
> +/*
> + * Enable modem status interrupts assigned to GPIOs
> + */
> +void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios);
> +
> #else /* GPIOLIB */
>
> static inline
> @@ -95,7 +126,7 @@ struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
> }
>
> static inline
> -struct mctrl_gpios *mctrl_gpio_init(struct device *dev, unsigned int idx)
> +struct mctrl_gpios *mctrl_gpio_init_dt(struct uart_port *port, unsigned int idx)
> {
> return ERR_PTR(-ENOSYS);
> }
> @@ -105,6 +136,28 @@ void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
> {
> }
>
> +static inline
> +int mctrl_gpio_request_irqs(struct mctrl_gpios *gpios)
> +{
> + /*return -ENOTSUP;*/
> + return 0;
> +}
> +
> +static inline
> +void mctrl_gpio_free_irqs(struct mctrl_gpios *gpios)
> +{
> +}
> +
> +static inline
> +void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
> +{
> +}
> +
> +static inline
> +void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
> +{
> +}
> +
> #endif /* GPIOLIB */
>
> #endif
> --
> 1.7.11.3
>
>
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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