Le 30/09/2015 10:19, Uwe Kleine-König a écrit :
> This allows to reduce the per-driver boiler plate considerably.
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
It seems good, even if I have a remark on the following patch:
Reviewed-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
> ---
> Documentation/serial/driver | 10 ++-
> drivers/tty/serial/serial_mctrl_gpio.c | 129 ++++++++++++++++++++++++++++++++-
> drivers/tty/serial/serial_mctrl_gpio.h | 35 +++++++++
> 3 files changed, 171 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/serial/driver b/Documentation/serial/driver
> index c415b0ef4493..379468e12680 100644
> --- a/Documentation/serial/driver
> +++ b/Documentation/serial/driver
> @@ -439,11 +439,13 @@ Modem control lines via GPIO
>
> Some helpers are provided in order to set/get modem control lines via GPIO.
>
> -mctrl_gpio_init(dev, idx):
> +mctrl_gpio_init(port, idx):
> This will get the {cts,rts,...}-gpios from device tree if they are
> present and request them, set direction etc, and return an
> allocated structure. devm_* functions are used, so there's no need
> to call mctrl_gpio_free().
> + As this sets up the irq handling make sure to not handle changes to the
> + gpio input lines in your driver, too.
>
> mctrl_gpio_free(dev, gpios):
> This will free the requested gpios in mctrl_gpio_init().
> @@ -458,3 +460,9 @@ mctrl_gpio_set(gpios, mctrl):
>
> mctrl_gpio_get(gpios, mctrl):
> This will update mctrl with the gpios values.
> +
> +mctrl_gpio_enable_ms(gpios):
> + Enables irqs and handling of changes to the ms lines.
> +
> +mctrl_gpio_disable_ms(gpios):
> + Disables irqs and handling of changes to the ms lines.
> diff --git a/drivers/tty/serial/serial_mctrl_gpio.c b/drivers/tty/serial/serial_mctrl_gpio.c
> index 1cdedd3bfb43..3eb57eb532f1 100644
> --- a/drivers/tty/serial/serial_mctrl_gpio.c
> +++ b/drivers/tty/serial/serial_mctrl_gpio.c
> @@ -12,18 +12,23 @@
> * but WITHOUT ANY WARRANTY; without even the implied warranty of
> * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> * GNU General Public License for more details.
> - *
> */
>
> #include <linux/err.h>
> #include <linux/device.h>
> +#include <linux/irq.h>
> #include <linux/gpio/consumer.h>
> #include <linux/termios.h>
> +#include <linux/serial_core.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;
> + bool mctrl_on;
> };
>
> static const struct {
> @@ -112,13 +117,133 @@ struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx)
> }
> EXPORT_SYMBOL_GPL(mctrl_gpio_init_noauto);
>
> +#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 & mctrl) & TIOCM_RI)
> + port->icount.rng++;
> +
> + if ((mctrl_diff & mctrl) & 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;
> +}
> +
> +struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx)
> +{
> + struct mctrl_gpios *gpios;
> + enum mctrl_gpio_idx i;
> +
> + gpios = mctrl_gpio_init_noauto(port->dev, idx);
> + if (IS_ERR(gpios))
> + return gpios;
> +
> + gpios->port = port;
> +
> + for (i = 0; i < UART_GPIO_MAX; ++i) {
> + int ret;
> +
> + if (!gpios->gpio[i] || mctrl_gpios_desc[i].dir_out)
> + continue;
> +
> + ret = gpiod_to_irq(gpios->gpio[i]);
> + if (ret <= 0) {
> + dev_err(port->dev,
> + "failed to find corresponding irq for %s (idx=%d, err=%d)\n",
> + mctrl_gpios_desc[i].name, idx, ret);
> + return ERR_PTR(ret);
> + }
> + gpios->irq[i] = ret;
> +
> + /* irqs should only be enabled in .enable_ms */
> + irq_set_status_flags(gpios->irq[i], IRQ_NOAUTOEN);
> +
> + ret = devm_request_irq(port->dev, gpios->irq[i],
> + mctrl_gpio_irq_handle,
> + IRQ_TYPE_EDGE_BOTH, dev_name(port->dev),
> + gpios);
> + if (ret) {
> + /* alternatively implement polling */
> + dev_err(port->dev,
> + "failed to request irq for %s (idx=%d, err=%d)\n",
> + mctrl_gpios_desc[i].name, idx, ret);
> + return ERR_PTR(ret);
> + }
> + }
> +
> + return gpios;
> +}
> +
> void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
> {
> enum mctrl_gpio_idx i;
>
> - for (i = 0; i < UART_GPIO_MAX; i++)
> + for (i = 0; i < UART_GPIO_MAX; i++) {
> + if (gpios->irq[i])
> + devm_free_irq(gpios->port->dev, gpios->irq[i], gpios);
> +
> if (gpios->gpio[i])
> devm_gpiod_put(dev, gpios->gpio[i]);
> + }
> devm_kfree(dev, gpios);
> }
> EXPORT_SYMBOL_GPL(mctrl_gpio_free);
> +
> +void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
> +{
> + enum mctrl_gpio_idx i;
> +
> + /* .enable_ms may be called multiple times */
> + if (gpios->mctrl_on)
> + return;
> +
> + gpios->mctrl_on = true;
> +
> + /* 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])
> + continue;
> +
> + 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;
> +
> + if (!gpios->mctrl_on)
> + return;
> +
> + gpios->mctrl_on = false;
> +
> + for (i = 0; i < UART_GPIO_MAX; ++i) {
> + if (!gpios->irq[i])
> + continue;
> +
> + disable_irq(gpios->irq[i]);
> + }
> +}
> diff --git a/drivers/tty/serial/serial_mctrl_gpio.h b/drivers/tty/serial/serial_mctrl_gpio.h
> index 6d046fcf744e..3c4ac9ae41f9 100644
> --- a/drivers/tty/serial/serial_mctrl_gpio.h
> +++ b/drivers/tty/serial/serial_mctrl_gpio.h
> @@ -22,6 +22,8 @@
> #include <linux/device.h>
> #include <linux/gpio/consumer.h>
>
> +struct uart_port;
> +
> enum mctrl_gpio_idx {
> UART_GPIO_CTS,
> UART_GPIO_DSR,
> @@ -60,6 +62,15 @@ 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 and sets up irq
> + * handling.
> + * 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 uart_port *port, unsigned int idx);
> +
> +/*
> * Request and set direction of modem control lines 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
> @@ -75,6 +86,16 @@ struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev,
> */
> void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios);
>
> +/*
> + * Enable gpio interrupts to report status line changes.
> + */
> +void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios);
> +
> +/*
> + * Disable gpio interrupts to report status line changes.
> + */
> +void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios);
> +
> #else /* GPIOLIB */
>
> static inline
> @@ -96,6 +117,12 @@ struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
> }
>
> static inline
> +struct mctrl_gpios *mctrl_gpio_init(struct uart_port *port, unsigned int idx)
> +{
> + return ERR_PTR(-ENOSYS);
> +}
> +
> +static inline
> struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx)
> {
> return ERR_PTR(-ENOSYS);
> @@ -106,6 +133,14 @@ void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios)
> {
> }
>
> +void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
> +{
> +}
> +
> +void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
> +{
> +}
> +
> #endif /* GPIOLIB */
>
> #endif
>
--
Nicolas Ferre
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