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serdev: Add serdev_device_write subroutine

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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: Rob Herring <robh@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Andrey Smirnov 2017-04-04 07:22:33 -07:00 committed by Greg Kroah-Hartman
parent e1dc9b0805
commit 6fe729c4bd
2 changed files with 46 additions and 7 deletions
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36
drivers/tty/serdev/core.c
View File

@ -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);

17
include/linux/serdev.h
View File

@ -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 */