From 2d13969ee7d892c69a9fff5af8c0356682290c41 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 14 Nov 2018 16:09:04 +0100 Subject: [PATCH] serdev: document the write functions using kernel-doc Document the asynchronous serdev_device_write_buf() and synchronous serdev_device_write() functions using kernel-doc. Specifically, mention that writing data only means that data has been buffered by the controller, and that the synchronous helper depends on serdev_device_write_wakeup() being called in the driver write_wakeup() callback. Signed-off-by: Johan Hovold Reviewed-by: Rob Herring Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serdev/core.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c index c7006bbb793a..a0ac16ee6575 100644 --- a/drivers/tty/serdev/core.c +++ b/drivers/tty/serdev/core.c @@ -217,6 +217,21 @@ void serdev_device_write_wakeup(struct serdev_device *serdev) } EXPORT_SYMBOL_GPL(serdev_device_write_wakeup); +/** + * serdev_device_write_buf() - write data asynchronously + * @serdev: serdev device + * @buf: data to be written + * @count: number of bytes to write + * + * Write data to the device asynchronously. + * + * Note that any accepted data has only been buffered by the controller; use + * serdev_device_wait_until_sent() to make sure the controller write buffer + * has actually been emptied. + * + * Return: The number of bytes written (less than count if not enough room in + * the write buffer), or a negative errno on errors. + */ int serdev_device_write_buf(struct serdev_device *serdev, const unsigned char *buf, size_t count) { @@ -229,6 +244,28 @@ int serdev_device_write_buf(struct serdev_device *serdev, } EXPORT_SYMBOL_GPL(serdev_device_write_buf); +/** + * serdev_device_write() - write data synchronously + * @serdev: serdev device + * @buf: data to be written + * @count: number of bytes to write + * @timeout: timeout in jiffies, or 0 to wait indefinitely + * + * Write data to the device synchronously by repeatedly calling + * serdev_device_write() until the controller has accepted all data (unless + * interrupted by a timeout or a signal). + * + * Note that any accepted data has only been buffered by the controller; use + * serdev_device_wait_until_sent() to make sure the controller write buffer + * has actually been emptied. + * + * Note that this function depends on serdev_device_write_wakeup() being + * called in the serdev driver write_wakeup() callback. + * + * Return: The number of bytes written (less than count if interrupted), + * -ETIMEDOUT or -ERESTARTSYS if interrupted before any bytes were written, or + * a negative errno on errors. + */ int serdev_device_write(struct serdev_device *serdev, const unsigned char *buf, size_t count, long timeout) -- 2.11.0