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authorJohan Hovold <johan@kernel.org>2018-11-14 16:09:04 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-11-27 19:44:21 +0100
commit2d13969ee7d892c69a9fff5af8c0356682290c41 (patch)
treea768e0f47ac75ac534483d345c86f6d552592b52 /drivers/tty/serdev
parent70d188041e6f1f92004f1d5d7ddfd5013273b7a5 (diff)
downloadlinux-2d13969ee7d892c69a9fff5af8c0356682290c41.tar.bz2
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 <johan@kernel.org> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serdev')
-rw-r--r--drivers/tty/serdev/core.c37
1 files changed, 37 insertions, 0 deletions
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)