diff options
author | Andrey Smirnov <andrew.smirnov@gmail.com> | 2017-04-04 17:22:33 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-04-08 19:51:00 +0300 |
commit | 6fe729c4bdae41b4c5a5ff21312f021a48c69399 (patch) | |
tree | 46e1fef43bf9104c00638fc2e40df99226833799 /drivers/tty/serdev | |
parent | e1dc9b08051a2c2e694edf48d1e704f07c7c143c (diff) |
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: 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>
Diffstat (limited to 'drivers/tty/serdev')
-rw-r--r-- | drivers/tty/serdev/core.c | 36 |
1 files changed, 31 insertions, 5 deletions
diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c index f4c6c90add78..6701d1011fce 100644 --- a/drivers/tty/serdev/core.c +++ b/drivers/tty/serdev/core.c @@ -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); |