platform/chrome: cros_ec: Put docs with the code

To avoid doc rot, put function documentations with code, not header.
Use kernel-doc style comments for exported functions.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

2 files changed, 103 insertions, 0 deletions

diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c
index fd77e6fa74c2..9b2d07422e17 100644
--- a/drivers/platform/chrome/cros_ec.c
+++ b/drivers/platform/chrome/cros_ec.c
@@ -104,6 +104,15 @@ static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event)
 	return ret;
 }
 
+/**
+ * cros_ec_register() - Register a new ChromeOS EC, using the provided info.
+ * @ec_dev: Device to register.
+ *
+ * Before calling this, allocate a pointer to a new device and then fill
+ * in all the fields up to the --private-- marker.
+ *
+ * Return: 0 on success or negative error code.
+ */
 int cros_ec_register(struct cros_ec_device *ec_dev)
 {
 	struct device *dev = ec_dev->dev;
@@ -198,6 +207,14 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
 }
 EXPORT_SYMBOL(cros_ec_register);
 
+/**
+ * cros_ec_unregister() - Remove a ChromeOS EC.
+ * @ec_dev: Device to unregister.
+ *
+ * Call this to deregister a ChromeOS EC, then clean up any private data.
+ *
+ * Return: 0 on success or negative error code.
+ */
 int cros_ec_unregister(struct cros_ec_device *ec_dev)
 {
 	if (ec_dev->pd)
@@ -209,6 +226,14 @@ int cros_ec_unregister(struct cros_ec_device *ec_dev)
 EXPORT_SYMBOL(cros_ec_unregister);
 
 #ifdef CONFIG_PM_SLEEP
+/**
+ * cros_ec_suspend() - Handle a suspend operation for the ChromeOS EC device.
+ * @ec_dev: Device to suspend.
+ *
+ * This can be called by drivers to handle a suspend event.
+ *
+ * Return: 0 on success or negative error code.
+ */
 int cros_ec_suspend(struct cros_ec_device *ec_dev)
 {
 	struct device *dev = ec_dev->dev;
@@ -243,6 +268,14 @@ static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev)
 					     1, ec_dev);
 }
 
+/**
+ * cros_ec_resume() - Handle a resume operation for the ChromeOS EC device.
+ * @ec_dev: Device to resume.
+ *
+ * This can be called by drivers to handle a resume event.
+ *
+ * Return: 0 on success or negative error code.
+ */
 int cros_ec_resume(struct cros_ec_device *ec_dev)
 {
 	int ret;
diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index f659f96bda12..7db58771ec77 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -117,6 +117,17 @@ static int send_command(struct cros_ec_device *ec_dev,
 	return ret;
 }
 
+/**
+ * cros_ec_prepare_tx() - Prepare an outgoing message in the output buffer.
+ * @ec_dev: Device to register.
+ * @msg: Message to write.
+ *
+ * This is intended to be used by all ChromeOS EC drivers, but at present
+ * only SPI uses it. Once LPC uses the same protocol it can start using it.
+ * I2C could use it now, with a refactor of the existing code.
+ *
+ * Return: 0 on success or negative error code.
+ */
 int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
 		       struct cros_ec_command *msg)
 {
@@ -141,6 +152,16 @@ int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
 }
 EXPORT_SYMBOL(cros_ec_prepare_tx);
 
+/**
+ * cros_ec_check_result() - Check ec_msg->result.
+ * @ec_dev: EC device.
+ * @msg: Message to check.
+ *
+ * This is used by ChromeOS EC drivers to check the ec_msg->result for
+ * errors and to warn about them.
+ *
+ * Return: 0 on success or negative error code.
+ */
 int cros_ec_check_result(struct cros_ec_device *ec_dev,
 			 struct cros_ec_command *msg)
 {
@@ -326,6 +347,13 @@ static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
 	return ret;
 }
 
+/**
+ * cros_ec_query_all() -  Query the protocol version supported by the
+ *         ChromeOS EC.
+ * @ec_dev: Device to register.
+ *
+ * Return: 0 on success or negative error code.
+ */
 int cros_ec_query_all(struct cros_ec_device *ec_dev)
 {
 	struct device *dev = ec_dev->dev;
@@ -453,6 +481,16 @@ exit:
 }
 EXPORT_SYMBOL(cros_ec_query_all);
 
+/**
+ * cros_ec_cmd_xfer() - Send a command to the ChromeOS EC.
+ * @ec_dev: EC device.
+ * @msg: Message to write.
+ *
+ * Call this to send a command to the ChromeOS EC.  This should be used
+ * instead of calling the EC's cmd_xfer() callback directly.
+ *
+ * Return: 0 on success or negative error code.
+ */
 int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
 		     struct cros_ec_command *msg)
 {
@@ -500,6 +538,18 @@ int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
 }
 EXPORT_SYMBOL(cros_ec_cmd_xfer);
 
+/**
+ * cros_ec_cmd_xfer_status() - Send a command to the ChromeOS EC.
+ * @ec_dev: EC device.
+ * @msg: Message to write.
+ *
+ * This function is identical to cros_ec_cmd_xfer, except it returns success
+ * status only if both the command was transmitted successfully and the EC
+ * replied with success status. It's not necessary to check msg->result when
+ * using this function.
+ *
+ * Return: The number of bytes transferred on success or negative error code.
+ */
 int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
 			    struct cros_ec_command *msg)
 {
@@ -584,6 +634,16 @@ static int get_keyboard_state_event(struct cros_ec_device *ec_dev)
 	return ec_dev->event_size;
 }
 
+/**
+ * cros_ec_get_next_event() - Fetch next event from the ChromeOS EC.
+ * @ec_dev: Device to fetch event from.
+ * @wake_event: Pointer to a bool set to true upon return if the event might be
+ *              treated as a wake event. Ignored if null.
+ *
+ * Return: negative error code on errors; 0 for no data; or else number of
+ * bytes received (i.e., an event was retrieved successfully). Event types are
+ * written out to @ec_dev->event_data.event_type on success.
+ */
 int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event)
 {
 	u8 event_type;
@@ -628,6 +688,16 @@ int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event)
 }
 EXPORT_SYMBOL(cros_ec_get_next_event);
 
+/**
+ * cros_ec_get_host_event() - Return a mask of event set by the ChromeOS EC.
+ * @ec_dev: Device to fetch event from.
+ *
+ * When MKBP is supported, when the EC raises an interrupt, we collect the
+ * events raised and call the functions in the ec notifier. This function
+ * is a helper to know which events are raised.
+ *
+ * Return: 0 on error or non-zero bitmask of one or more EC_HOST_EVENT_*.
+ */
 u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev)
 {
 	u32 host_event;