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Commit 6fe729c4 authored by Andrey Smirnov's avatar Andrey Smirnov Committed by Greg Kroah-Hartman
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serdev: Add serdev_device_write subroutine 



Add serdev_device_write() a blocking call allowing to transfer
arbitraty amount of data (potentially exceeding amount that
serdev_device_write_buf can process in a single call)

To support that, also add serdev_device_write_wakeup().

Drivers wanting to use full extent of serdev_device_write
functionality are expected to provide serdev_device_write_wakeup() as
a sole handler of .write_wakeup event or call it as a part of driver's
custom .write_wakeup code.

Because serdev_device_write() subroutine is a superset of
serdev_device_write_buf() the patch re-impelements latter is terms of
the former. For drivers wanting to just use serdev_device_write_buf()
.write_wakeup handler is optional.

Cc: cphealy@gmail.com
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: default avatarRob Herring <robh@kernel.org>
Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: default avatarAndrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e1dc9b08

drivers/tty/serdev/core.c

+31 −5
Original line number Diff line number Diff line
@@ -116,17 +116,41 @@ void serdev_device_close(struct serdev_device *serdev) 
}

EXPORT_SYMBOL_GPL(serdev_device_close);



int serdev_device_write_buf(struct serdev_device *serdev,

			    const unsigned char *buf, size_t count)

void serdev_device_write_wakeup(struct serdev_device *serdev)

{

	complete(&serdev->write_comp);

}

EXPORT_SYMBOL_GPL(serdev_device_write_wakeup);



int serdev_device_write(struct serdev_device *serdev,

			const unsigned char *buf, size_t count,

			unsigned long timeout)

{

	struct serdev_controller *ctrl = serdev->ctrl;

	int ret;



	if (!ctrl || !ctrl->ops->write_buf)

	if (!ctrl || !ctrl->ops->write_buf ||

	    (timeout && !serdev->ops->write_wakeup))

		return -EINVAL;



	return ctrl->ops->write_buf(ctrl, buf, count);

	mutex_lock(&serdev->write_lock);

	do {

		reinit_completion(&serdev->write_comp);



		ret = ctrl->ops->write_buf(ctrl, buf, count);

		if (ret < 0)

			break;



		buf += ret;

		count -= ret;



	} while (count &&

		 (timeout = wait_for_completion_timeout(&serdev->write_comp,

							timeout)));

	mutex_unlock(&serdev->write_lock);

	return ret < 0 ? ret : (count ? -ETIMEDOUT : 0);

}

EXPORT_SYMBOL_GPL(serdev_device_write_buf);

EXPORT_SYMBOL_GPL(serdev_device_write);



void serdev_device_write_flush(struct serdev_device *serdev)

{
@@ -232,6 +256,8 @@ struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl) 
	serdev->dev.parent = &ctrl->dev;

	serdev->dev.bus = &serdev_bus_type;

	serdev->dev.type = &serdev_device_type;

	init_completion(&serdev->write_comp);

	mutex_init(&serdev->write_lock);

	return serdev;

}

EXPORT_SYMBOL_GPL(serdev_device_alloc);

include/linux/serdev.h

+15 −2
Original line number Diff line number Diff line
@@ -39,12 +39,16 @@ struct serdev_device_ops { 
 * @nr:		Device number on serdev bus.

 * @ctrl:	serdev controller managing this device.

 * @ops:	Device operations.

 * @write_comp	Completion used by serdev_device_write() internally

 * @write_lock	Lock to serialize access when writing data

 */

struct serdev_device {

	struct device dev;

	int nr;

	struct serdev_controller *ctrl;

	const struct serdev_device_ops *ops;

	struct completion write_comp;

	struct mutex write_lock;

};



static inline struct serdev_device *to_serdev_device(struct device *d)
@@ -186,7 +190,8 @@ int serdev_device_open(struct serdev_device *); 
void serdev_device_close(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);

void serdev_device_write_wakeup(struct serdev_device *);

int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, unsigned long);

void serdev_device_write_flush(struct serdev_device *);

int serdev_device_write_room(struct serdev_device *);
@@ -223,7 +228,8 @@ static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev 
	return 0;

}

static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {}

static inline int serdev_device_write_buf(struct serdev_device *sdev, const unsigned char *buf, size_t count)

static inline int serdev_device_write(struct serdev_device *sdev, const unsigned char *buf,

				      size_t count, unsigned long timeout)

{

	return -ENODEV;

}
@@ -259,4 +265,11 @@ static inline struct device *serdev_tty_port_register(struct tty_port *port, 
static inline void serdev_tty_port_unregister(struct tty_port *port) {}

#endif /* CONFIG_SERIAL_DEV_CTRL_TTYPORT */



static inline int serdev_device_write_buf(struct serdev_device *serdev,

					  const unsigned char *data,

					  size_t count)

{

	return serdev_device_write(serdev, data, count, 0);

}



#endif /*_LINUX_SERDEV_H */