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authorMaxime Ripard <maxime@cerno.tech>2021-06-16 17:15:27 +0300
committerMaxime Ripard <maxime@cerno.tech>2021-06-23 15:32:26 +0300
commit14407d3afed07c48a536be01d92dcd9812bcb3d5 (patch)
tree40dc6b2486ffb773c52b79a8cd7502a239731f51 /include/drm/drm_dp_helper.h
parent5c68ab9276aae473b6f07191ad115bfcb09dc938 (diff)
downloadlinux-14407d3afed07c48a536be01d92dcd9812bcb3d5.tar.xz
drm/dp_helper: Rework the drm_dp_aux documentation
Split the existing documentation to move the comments on particular fields next to them. Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Maxime Ripard <maxime@cerno.tech> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20210616141529.630719-1-maxime@cerno.tech
Diffstat (limited to 'include/drm/drm_dp_helper.h')
-rw-r--r--include/drm/drm_dp_helper.h102
1 files changed, 69 insertions, 33 deletions
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 0bd6396648b4..683aa9892bad 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1859,35 +1859,6 @@ struct drm_dp_aux_cec {
/**
* struct drm_dp_aux - DisplayPort AUX channel
- * @name: user-visible name of this AUX channel and the I2C-over-AUX adapter
- * @ddc: I2C adapter that can be used for I2C-over-AUX communication
- * @dev: pointer to struct device that is the parent for this AUX channel
- * @drm_dev: pointer to the &drm_device that owns this AUX channel. Beware, this
- * may be %NULL before drm_dp_aux_register() has been called.
- * @crtc: backpointer to the crtc that is currently using this AUX channel
- * @hw_mutex: internal mutex used for locking transfers
- * @crc_work: worker that captures CRCs for each frame
- * @crc_count: counter of captured frame CRCs
- * @transfer: transfers a message representing a single AUX transaction
- *
- * The @dev field should be set to a pointer to the device that implements the
- * AUX channel. As well, the @drm_dev field should be set to the &drm_device
- * that will be using this AUX channel as early as possible. For many graphics
- * drivers this should happen before drm_dp_aux_init(), however it's perfectly
- * fine to set this field later so long as it's assigned before calling
- * drm_dp_aux_register().
- *
- * The @name field may be used to specify the name of the I2C adapter. If set to
- * %NULL, dev_name() of @dev will be used.
- *
- * Drivers provide a hardware-specific implementation of how transactions are
- * executed via the @transfer() function. A pointer to a &drm_dp_aux_msg
- * structure describing the transaction is passed into this function. Upon
- * success, the implementation should return the number of payload bytes that
- * were transferred, or a negative error-code on failure. Helpers propagate
- * errors from the @transfer() function, with the exception of the %-EBUSY
- * error, which causes a transaction to be retried. On a short, helpers will
- * return %-EPROTO to make it simpler to check for failure.
*
* An AUX channel can also be used to transport I2C messages to a sink. A
* typical application of that is to access an EDID that's present in the sink
@@ -1898,22 +1869,87 @@ struct drm_dp_aux_cec {
* transfers by default; if a partial response is received, the adapter will
* drop down to the size given by the partial response for this transaction
* only.
- *
- * Note that the aux helper code assumes that the @transfer() function only
- * modifies the reply field of the &drm_dp_aux_msg structure. The retry logic
- * and i2c helpers assume this is the case.
*/
struct drm_dp_aux {
+ /**
+ * @name: user-visible name of this AUX channel and the
+ * I2C-over-AUX adapter.
+ *
+ * It's also used to specify the name of the I2C adapter. If set
+ * to %NULL, dev_name() of @dev will be used.
+ */
const char *name;
+
+ /**
+ * @ddc: I2C adapter that can be used for I2C-over-AUX
+ * communication
+ */
struct i2c_adapter ddc;
+
+ /**
+ * @dev: pointer to struct device that is the parent for this
+ * AUX channel.
+ */
struct device *dev;
+
+ /**
+ * @drm_dev: pointer to the &drm_device that owns this AUX channel.
+ * Beware, this may be %NULL before drm_dp_aux_register() has been
+ * called.
+ *
+ * It should be set to the &drm_device that will be using this AUX
+ * channel as early as possible. For many graphics drivers this should
+ * happen before drm_dp_aux_init(), however it's perfectly fine to set
+ * this field later so long as it's assigned before calling
+ * drm_dp_aux_register().
+ */
struct drm_device *drm_dev;
+
+ /**
+ * @crtc: backpointer to the crtc that is currently using this
+ * AUX channel
+ */
struct drm_crtc *crtc;
+
+ /**
+ * @hw_mutex: internal mutex used for locking transfers.
+ */
struct mutex hw_mutex;
+
+ /**
+ * @crc_work: worker that captures CRCs for each frame
+ */
struct work_struct crc_work;
+
+ /**
+ * @crc_count: counter of captured frame CRCs
+ */
u8 crc_count;
+
+ /**
+ * @transfer: transfers a message representing a single AUX
+ * transaction.
+ *
+ * This is a hardware-specific implementation of how
+ * transactions are executed that the drivers must provide.
+ *
+ * A pointer to a &drm_dp_aux_msg structure describing the
+ * transaction is passed into this function. Upon success, the
+ * implementation should return the number of payload bytes that
+ * were transferred, or a negative error-code on failure.
+ *
+ * Helpers will propagate these errors, with the exception of
+ * the %-EBUSY error, which causes a transaction to be retried.
+ * On a short, helpers will return %-EPROTO to make it simpler
+ * to check for failure.
+ *
+ * The @transfer() function must only modify the reply field of
+ * the &drm_dp_aux_msg structure. The retry logic and i2c
+ * helpers assume this is the case.
+ */
ssize_t (*transfer)(struct drm_dp_aux *aux,
struct drm_dp_aux_msg *msg);
+
/**
* @i2c_nack_count: Counts I2C NACKs, used for DP validation.
*/