@@ -984,9 +984,13 @@ static const u8 edid_header[] = {
0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00
};
- /*
- * Sanity check the header of the base EDID block. Return 8 if the header
- * is perfect, down to 0 if it's totally wrong.
+/**
+ * drm_edid_header_is_valid - sanity check the header of the base EDID block
+ * @raw_edid: pointer to raw base EDID block
+ *
+ * Sanity check the header of the base EDID block.
+ *
+ * Return: 8 if the header is perfect, down to 0 if it's totally wrong.
*/
int drm_edid_header_is_valid(const u8 *raw_edid)
{
@@ -1005,9 +1009,16 @@ module_param_named(edid_fixup, edid_fixup, int, 0400);
MODULE_PARM_DESC(edid_fixup,
"Minimum number of valid EDID header bytes (0-8, default 6)");
-/*
- * Sanity check the EDID block (base or extension). Return 0 if the block
- * doesn't check out, or 1 if it's valid.
+/**
+ * drm_edid_block_valid - Sanity check the EDID block (base or extension)
+ * @raw_edid: pointer to raw EDID block
+ * @block: type of block to validate (0 for base, extension otherwise)
+ * @print_bad_edid: if true, dump bad EDID blocks to the console
+ *
+ * Validate a base or extension EDID block and optionally dump bad blocks to
+ * the console.
+ *
+ * Return: True if the block is valid, false otherwise.
*/
bool drm_edid_block_valid(u8 *raw_edid, int block, bool print_bad_edid)
{
@@ -1077,6 +1088,8 @@ EXPORT_SYMBOL(drm_edid_block_valid);
* @edid: EDID data
*
* Sanity-check an entire EDID record (including extensions)
+ *
+ * Return: True if the EDID data is valid, false otherwise.
*/
bool drm_edid_is_valid(struct edid *edid)
{
@@ -1096,18 +1109,15 @@ EXPORT_SYMBOL(drm_edid_is_valid);
#define DDC_SEGMENT_ADDR 0x30
/**
- * Get EDID information via I2C.
- *
- * @adapter : i2c device adaptor
+ * drm_do_probe_ddc_edid() - get EDID information via I2C
+ * @adapter: I2C device adaptor
* @buf: EDID data buffer to be filled
* @block: 128 byte EDID block to start fetching from
* @len: EDID data buffer length to fetch
*
- * Returns:
- *
- * 0 on success or -1 on failure.
+ * Try to fetch EDID information by calling I2C driver functions.
*
- * Try to fetch EDID information by calling i2c driver function.
+ * Return: 0 on success or -1 on failure.
*/
static int
drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf,
@@ -1118,7 +1128,8 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf,
unsigned char xfers = segment ? 3 : 2;
int ret, retries = 5;
- /* The core i2c driver will automatically retry the transfer if the
+ /*
+ * The core I2C driver will automatically retry the transfer if the
* adapter reports EAGAIN. However, we find that bit-banging transfers
* are susceptible to errors under a heavily loaded machine and
* generate spurious NAKs and timeouts. Retrying the transfer
@@ -1144,10 +1155,10 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf,
}
};
- /*
- * Avoid sending the segment addr to not upset non-compliant ddc
- * monitors.
- */
+ /*
+ * Avoid sending the segment addr to not upset non-compliant
+ * DDC monitors.
+ */
ret = i2c_transfer(adapter, &msgs[3 - xfers], xfers);
if (ret == -ENXIO) {
@@ -1246,12 +1257,10 @@ out:
}
/**
- * Probe DDC presence.
- * @adapter: i2c adapter to probe
+ * drm_probe_ddc() - probe DDC presence
+ * @adapter: I2C adapter to probe
*
- * Returns:
- *
- * 1 on success
+ * Return: True on success, false on failure.
*/
bool
drm_probe_ddc(struct i2c_adapter *adapter)
@@ -1265,12 +1274,12 @@ EXPORT_SYMBOL(drm_probe_ddc);
/**
* drm_get_edid - get EDID data, if available
* @connector: connector we're probing
- * @adapter: i2c adapter to use for DDC
+ * @adapter: I2C adapter to use for DDC
*
- * Poke the given i2c channel to grab EDID data if possible. If found,
+ * Poke the given I2C channel to grab EDID data if possible. If found,
* attach it to the connector.
*
- * Return edid data or NULL if we couldn't find any.
+ * Return: Pointer to valid EDID or NULL if we couldn't find any.
*/
struct edid *drm_get_edid(struct drm_connector *connector,
struct i2c_adapter *adapter)
@@ -1288,7 +1297,7 @@ EXPORT_SYMBOL(drm_get_edid);
* drm_edid_duplicate - duplicate an EDID and the extensions
* @edid: EDID to duplicate
*
- * Return duplicate edid or NULL on allocation failure.
+ * Return: Pointer to duplicated EDID or NULL on allocation failure.
*/
struct edid *drm_edid_duplicate(const struct edid *edid)
{
@@ -1411,7 +1420,8 @@ mode_is_rb(const struct drm_display_mode *mode)
* @rb: Mode reduced-blanking-ness
*
* Walk the DMT mode list looking for a match for the given parameters.
- * Return a newly allocated copy of the mode, or NULL if not found.
+ *
+ * Return: A newly allocated copy of the mode, or NULL if not found.
*/
struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
int hsize, int vsize, int fresh,
@@ -2139,7 +2149,7 @@ do_established_modes(struct detailed_timing *timing, void *c)
/**
* add_established_modes - get est. modes from EDID and add them
- * @connector: connector of for the EDID block
+ * @connector: connector to add mode(s) to
* @edid: EDID block to scan
*
* Each EDID block contains a bitmap of the supported "established modes" list
@@ -2201,7 +2211,7 @@ do_standard_modes(struct detailed_timing *timing, void *c)
/**
* add_standard_modes - get std. modes from EDID and add them
- * @connector: connector of for the EDID block
+ * @connector: connector to add mode(s) to
* @edid: EDID block to scan
*
* Standard modes can be calculated using the appropriate standard (DMT,
@@ -2422,7 +2432,7 @@ cea_mode_alternate_clock(const struct drm_display_mode *cea_mode)
* drm_match_cea_mode - look for a CEA mode matching given mode
* @to_match: display mode
*
- * Returns the CEA Video ID (VIC) of the mode or 0 if it isn't a CEA-861
+ * Return: The CEA Video ID (VIC) of the mode or 0 if it isn't a CEA-861
* mode.
*/
u8 drm_match_cea_mode(const struct drm_display_mode *to_match)
@@ -3017,11 +3027,9 @@ monitor_name(struct detailed_timing *t, void *data)
* @connector: connector corresponding to the HDMI/DP sink
* @edid: EDID to parse
*
- * Fill the ELD (EDID-Like Data) buffer for passing to the audio driver.
- * Some ELD fields are left to the graphics driver caller:
- * - Conn_Type
- * - HDCP
- * - Port_ID
+ * Fill the ELD (EDID-Like Data) buffer for passing to the audio driver. The
+ * Conn_Type, HDCP and Port_ID ELD fields are left for the graphics driver to
+ * fill in.
*/
void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
{
@@ -3105,9 +3113,10 @@ EXPORT_SYMBOL(drm_edid_to_eld);
* @sads: pointer that will be set to the extracted SADs
*
* Looks for CEA EDID block and extracts SADs (Short Audio Descriptors) from it.
- * Note: returned pointer needs to be kfreed
*
- * Return number of found SADs or negative number on error.
+ * Note: The returned pointer needs to be freed using kfree().
+ *
+ * Return: The number of found SADs or negative number on error.
*/
int drm_edid_to_sad(struct edid *edid, struct cea_sad **sads)
{
@@ -3164,9 +3173,11 @@ EXPORT_SYMBOL(drm_edid_to_sad);
* @sadb: pointer to the speaker block
*
* Looks for CEA EDID block and extracts the Speaker Allocation Data Block from it.
- * Note: returned pointer needs to be kfreed
*
- * Return number of found Speaker Allocation Blocks or negative number on error.
+ * Note: The returned pointer needs to be freed using kfree().
+ *
+ * Return: The number of found Speaker Allocation Blocks or negative number on
+ * error.
*/
int drm_edid_to_speaker_allocation(struct edid *edid, u8 **sadb)
{
@@ -3213,9 +3224,12 @@ int drm_edid_to_speaker_allocation(struct edid *edid, u8 **sadb)
EXPORT_SYMBOL(drm_edid_to_speaker_allocation);
/**
- * drm_av_sync_delay - HDMI/DP sink audio-video sync delay in millisecond
+ * drm_av_sync_delay - compute the HDMI/DP sink audio-video sync delay
* @connector: connector associated with the HDMI/DP sink
* @mode: the display mode
+ *
+ * Return: The HDMI/DP sink's audio-video sync delay in milliseconds or 0 if
+ * the sink doesn't support audio or video.
*/
int drm_av_sync_delay(struct drm_connector *connector,
struct drm_display_mode *mode)
@@ -3257,6 +3271,9 @@ EXPORT_SYMBOL(drm_av_sync_delay);
*
* It's possible for one encoder to be associated with multiple HDMI/DP sinks.
* The policy is now hard coded to simply use the first HDMI/DP sink's ELD.
+ *
+ * Return: The connector associated with the first HDMI/DP sink that has ELD
+ * attached to it.
*/
struct drm_connector *drm_select_eld(struct drm_encoder *encoder,
struct drm_display_mode *mode)
@@ -3273,11 +3290,12 @@ struct drm_connector *drm_select_eld(struct drm_encoder *encoder,
EXPORT_SYMBOL(drm_select_eld);
/**
- * drm_detect_hdmi_monitor - detect whether monitor is hdmi.
+ * drm_detect_hdmi_monitor - detect whether monitor is HDMI
* @edid: monitor EDID information
*
* Parse the CEA extension according to CEA-861-B.
- * Return true if HDMI, false if not or unknown.
+ *
+ * Return: True if the monitor is HDMI, false if not or unknown.
*/
bool drm_detect_hdmi_monitor(struct edid *edid)
{
@@ -3315,6 +3333,7 @@ EXPORT_SYMBOL(drm_detect_hdmi_monitor);
* audio format, assume at least 'basic audio' support, even if 'basic
* audio' is not defined in EDID.
*
+ * Return: True if the monitor supports audio, false otherwise.
*/
bool drm_detect_monitor_audio(struct edid *edid)
{
@@ -3358,6 +3377,8 @@ EXPORT_SYMBOL(drm_detect_monitor_audio);
* Check whether the monitor reports the RGB quantization range selection
* as supported. The AVI infoframe can then be used to inform the monitor
* which quantization range (full or limited) is used.
+ *
+ * Return: True if the RGB quantization range is selectable, false otherwise.
*/
bool drm_rgb_quant_range_selectable(struct edid *edid)
{
@@ -3462,11 +3483,11 @@ static void drm_add_display_info(struct edid *edid,
/**
* drm_add_edid_modes - add modes from EDID data, if available
* @connector: connector we're probing
- * @edid: edid data
+ * @edid: EDID data
*
* Add the specified modes to the connector's mode list.
*
- * Return number of modes added or 0 if we couldn't find any.
+ * Return: The number of modes added or 0 if we couldn't find any.
*/
int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
{
@@ -3528,7 +3549,7 @@ EXPORT_SYMBOL(drm_add_edid_modes);
* Add the specified modes to the connector's mode list. Only when the
* hdisplay/vdisplay is not beyond the given limit, it will be added.
*
- * Return number of modes added or 0 if we couldn't find any.
+ * Return: The number of modes added or 0 if we couldn't find any.
*/
int drm_add_modes_noedid(struct drm_connector *connector,
int hdisplay, int vdisplay)
@@ -3567,13 +3588,22 @@ int drm_add_modes_noedid(struct drm_connector *connector,
}
EXPORT_SYMBOL(drm_add_modes_noedid);
+/**
+ * drm_set_preferred_mode - Sets the preferred mode of a connector
+ * @connector: connector whose mode list should be processed
+ * @hpref: horizontal resolution of preferred mode
+ * @vpref: vertical resolution of preferred mode
+ *
+ * Marks a mode as preferred if it matches the resolution specified by @hpref
+ * and @vpref.
+ */
void drm_set_preferred_mode(struct drm_connector *connector,
int hpref, int vpref)
{
struct drm_display_mode *mode;
list_for_each_entry(mode, &connector->probed_modes, head) {
- if (mode->hdisplay == hpref &&
+ if (mode->hdisplay == hpref &&
mode->vdisplay == vpref)
mode->type |= DRM_MODE_TYPE_PREFERRED;
}
@@ -3586,7 +3616,7 @@ EXPORT_SYMBOL(drm_set_preferred_mode);
* @frame: HDMI AVI infoframe
* @mode: DRM display mode
*
- * Returns 0 on success or a negative error code on failure.
+ * Return: 0 on success or a negative error code on failure.
*/
int
drm_hdmi_avi_infoframe_from_display_mode(struct hdmi_avi_infoframe *frame,
@@ -3650,7 +3680,7 @@ s3d_structure_from_display_mode(const struct drm_display_mode *mode)
* 4k or stereoscopic 3D mode. So when giving any other mode as input this
* function will return -EINVAL, error that can be safely ignored.
*
- * Returns 0 on success or a negative error code on failure.
+ * Return: 0 on success or a negative error code on failure.
*/
int
drm_hdmi_vendor_infoframe_from_display_mode(struct hdmi_vendor_infoframe *frame,