Re: [PATCH v8 2/5] serdev: Introduce devm_serdev_device_open()

[Guenter Roeck]

On 10/18/2017 10:01 AM, Andrey Smirnov wrote:
> Add code implementing managed version of serdev_device_open() for
> serdev device drivers that "open" the device during driver's lifecycle
> only once (e.g. opened in .probe() and closed in .remove()).
>
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: linux-serial@xxxxxxxxxxxxxxx
> Cc: Rob Herring <robh@xxxxxxxxxx>
> Cc: cphealy@xxxxxxxxx
> Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
> Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
> Cc: Nikita Yushchenko <nikita.yoush@xxxxxxxxxxxxxxxxxx>
> Cc: Lee Jones <lee.jones@xxxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: Pavel Machek <pavel@xxxxxx>
> Cc: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> Cc: Johan Hovold <johan@xxxxxxxxxx>
> Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>

Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>

> ---
>   Documentation/driver-model/devres.txt |  3 +++
>   drivers/tty/serdev/core.c             | 27 +++++++++++++++++++++++++++
>   include/linux/serdev.h                |  1 +
>   3 files changed, 31 insertions(+)
>
> diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
> index 69f08c0f23a8..e9c6b5cfeec1 100644
> --- a/Documentation/driver-model/devres.txt
> +++ b/Documentation/driver-model/devres.txt
> @@ -383,6 +383,9 @@ RESET
>     devm_reset_control_get()
>     devm_reset_controller_register()
>   
> +SERDEV
> +  devm_serdev_device_open()
> +
>   SLAVE DMA ENGINE
>     devm_acpi_dma_controller_register()
>   
> diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
> index f500f6a2ca88..b3a785665c6f 100644
> --- a/drivers/tty/serdev/core.c
> +++ b/drivers/tty/serdev/core.c
> @@ -116,6 +116,33 @@ void serdev_device_close(struct serdev_device *serdev)
>   }
>   EXPORT_SYMBOL_GPL(serdev_device_close);
>   
> +static void devm_serdev_device_release(struct device *dev, void *dr)
> +{
> +	serdev_device_close(*(struct serdev_device **)dr);
> +}
> +
> +int devm_serdev_device_open(struct device *dev, struct serdev_device *serdev)
> +{
> +	struct serdev_device **dr;
> +	int ret;
> +
> +	dr = devres_alloc(devm_serdev_device_release, sizeof(*dr), GFP_KERNEL);
> +	if (!dr)
> +		return -ENOMEM;
> +
> +	ret = serdev_device_open(serdev);
> +	if (ret) {
> +		devres_free(dr);
> +		return ret;
> +	}
> +
> +	*dr = serdev;
> +	devres_add(dev, dr);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(devm_serdev_device_open);
> +
>   void serdev_device_write_wakeup(struct serdev_device *serdev)
>   {
>   	complete(&serdev->write_comp);
> diff --git a/include/linux/serdev.h b/include/linux/serdev.h
> index e69402d4a8ae..9929063bd45d 100644
> --- a/include/linux/serdev.h
> +++ b/include/linux/serdev.h
> @@ -193,6 +193,7 @@ static inline int serdev_controller_receive_buf(struct serdev_controller *ctrl,
>   
>   int serdev_device_open(struct serdev_device *);
>   void serdev_device_close(struct serdev_device *);
> +int devm_serdev_device_open(struct device *, struct serdev_device *);
>   unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int);
>   void serdev_device_set_flow_control(struct serdev_device *, bool);
>   int serdev_device_write_buf(struct serdev_device *, const unsigned char *, size_t);