From 50be3d851080b175cd9c7c701b1c796fe1fd6bf5 Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime@cerno.tech>
Date: Wed, 16 Jun 2021 16:15:27 +0200
Subject: drm/dp_helper: Rework the drm_dp_aux documentation
Git-commit: 14407d3afed07c48a536be01d92dcd9812bcb3d5
Patch-mainline: v5.15-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
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
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
include/drm/drm_dp_helper.h | 102 ++++++++++++++++++++++++------------
1 file changed, 69 insertions(+), 33 deletions(-)
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index ddd51666d1f3..d4be8869a617 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1876,35 +1876,6 @@ 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
@@ -1915,22 +1886,87 @@ 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.
*/
--
2.38.1