@@ -965,6 +965,7 @@ int max_width, max_height;</synopsis>
</itemizedlist>
<sect2>
<title>Display Modes Function Reference</title>
+!Iinclude/drm/drm_modes.h
!Edrivers/gpu/drm/drm_modes.c
</sect2>
<sect2>
@@ -63,9 +63,10 @@ EXPORT_SYMBOL(drm_mode_debug_printmodeline);
* drm_mode_create - create a new display mode
* @dev: DRM device
*
- * Create a new drm_display_mode, give it an ID, and return it.
+ * Create a new, cleared drm_display_mode with kzalloc, allocate an ID for it
+ * and return it.
*
- * RETURNS:
+ * Returns:
* Pointer to new mode on success, NULL on error.
*/
struct drm_display_mode *drm_mode_create(struct drm_device *dev)
@@ -90,7 +91,7 @@ EXPORT_SYMBOL(drm_mode_create);
* @dev: DRM device
* @mode: mode to remove
*
- * Free @mode's unique identifier, then free it.
+ * Release @mode's unique ID, then free it @mode structure itself using kfree.
*/
void drm_mode_destroy(struct drm_device *dev, struct drm_display_mode *mode)
{
@@ -104,11 +105,13 @@ void drm_mode_destroy(struct drm_device *dev, struct drm_display_mode *mode)
EXPORT_SYMBOL(drm_mode_destroy);
/**
- * drm_mode_probed_add - add a mode to a connector's probed mode list
+ * drm_mode_probed_add - add a mode to a connector's probed_mode list
* @connector: connector the new mode
* @mode: mode data
*
- * Add @mode to @connector's mode list for later use.
+ * Add @mode to @connector's probed_mode list for later use. This list should
+ * then in a second step get filtered and all the modes actually supported by
+ * the hardware moved to the @connector's modes list.
*/
void drm_mode_probed_add(struct drm_connector *connector,
struct drm_display_mode *mode)
@@ -120,16 +123,14 @@ void drm_mode_probed_add(struct drm_connector *connector,
EXPORT_SYMBOL(drm_mode_probed_add);
/**
- * drm_cvt_mode -create a modeline based on CVT algorithm
- * @dev: DRM device
+ * drm_cvt_mode -create a modeline based on the CVT algorithm
+ * @dev: drm device
* @hdisplay: hdisplay size
* @vdisplay: vdisplay size
- * @vrefresh : vrefresh rate
- * @reduced : Whether the GTF calculation is simplified
- * @interlaced:Whether the interlace is supported
- * @margins: whether to add margins or not
- *
- * return the modeline based on CVT algorithm
+ * @vrefresh: vrefresh rate
+ * @reduced: whether to use reduced blanking
+ * @interlaced: whether to compute an interlaced mode
+ * @margins: whether to add margins (borders)
*
* This function is called to generate the modeline based on CVT algorithm
* according to the hdisplay, vdisplay, vrefresh.
@@ -139,6 +140,11 @@ EXPORT_SYMBOL(drm_mode_probed_add);
*
* And it is copied from xf86CVTmode in xserver/hw/xfree86/modes/xf86cvt.c.
* What I have done is to translate it by using integer calculation.
+ *
+ * Returns:
+ * The modeline based on the CVT algorithm stored in a drm_display_mode object.
+ * The display mode object is allocated with drm_mode_create(). Returns NULL
+ * when no mode could be allocated.
*/
struct drm_display_mode *drm_cvt_mode(struct drm_device *dev, int hdisplay,
int vdisplay, int vrefresh,
@@ -338,23 +344,25 @@ struct drm_display_mode *drm_cvt_mode(struct drm_device *dev, int hdisplay,
EXPORT_SYMBOL(drm_cvt_mode);
/**
- * drm_gtf_mode_complex - create the modeline based on full GTF algorithm
- *
- * @dev :drm device
- * @hdisplay :hdisplay size
- * @vdisplay :vdisplay size
- * @vrefresh :vrefresh rate.
- * @interlaced :whether the interlace is supported
- * @margins :desired margin size
+ * drm_gtf_mode_complex - create the modeline based on the full GTF algorithm
+ * @dev: drm device
+ * @hdisplay: hdisplay size
+ * @vdisplay: vdisplay size
+ * @vrefresh: vrefresh rate.
+ * @interlaced: whether to compute an interlaced mode
+ * @margins: desired margin (borders) size
* @GTF_M: extended GTF formula parameters
* @GTF_2C: extended GTF formula parameters
* @GTF_K: extended GTF formula parameters
* @GTF_2J: extended GTF formula parameters
*
- * return the modeline based on full GTF algorithm.
- *
* GTF feature blocks specify C and J in multiples of 0.5, so we pass them
* in here multiplied by two. For a C of 40, pass in 80.
+ *
+ * Returns:
+ * The modeline based on the full GTF algorithm stored in a drm_display_mode object.
+ * The display mode object is allocated with drm_mode_create(). Returns NULL
+ * when no mode could be allocated.
*/
struct drm_display_mode *
drm_gtf_mode_complex(struct drm_device *dev, int hdisplay, int vdisplay,
@@ -524,14 +532,13 @@ drm_gtf_mode_complex(struct drm_device *dev, int hdisplay, int vdisplay,
EXPORT_SYMBOL(drm_gtf_mode_complex);
/**
- * drm_gtf_mode - create the modeline based on GTF algorithm
- *
- * @dev :drm device
- * @hdisplay :hdisplay size
- * @vdisplay :vdisplay size
- * @vrefresh :vrefresh rate.
- * @interlaced :whether the interlace is supported
- * @margins :whether the margin is supported
+ * drm_gtf_mode - create the modeline based on the GTF algorithm
+ * @dev: drm device
+ * @hdisplay: hdisplay size
+ * @vdisplay: vdisplay size
+ * @vrefresh: vrefresh rate.
+ * @interlaced: whether to compute an interlaced mode
+ * @margins: desired margin (borders) size
*
* return the modeline based on GTF algorithm
*
@@ -550,6 +557,11 @@ EXPORT_SYMBOL(drm_gtf_mode_complex);
* C = 40
* K = 128
* J = 20
+ *
+ * Returns:
+ * The modeline based on the GTF algorithm stored in a drm_display_mode object.
+ * The display mode object is allocated with drm_mode_create(). Returns NULL
+ * when no mode could be allocated.
*/
struct drm_display_mode *
drm_gtf_mode(struct drm_device *dev, int hdisplay, int vdisplay, int vrefresh,
@@ -562,6 +574,13 @@ drm_gtf_mode(struct drm_device *dev, int hdisplay, int vdisplay, int vrefresh,
EXPORT_SYMBOL(drm_gtf_mode);
#ifdef CONFIG_VIDEOMODE_HELPERS
+/**
+ * drm_display_mode_from_videomode - fill in @dmode using @vm,
+ * @vm: videomode structure to use as source
+ * @dmode: drm_display_mode structure to use as destination
+ *
+ * Fills out @dmode using the display mode specified in @vm.
+ */
void drm_display_mode_from_videomode(const struct videomode *vm,
struct drm_display_mode *dmode)
{
@@ -606,6 +625,9 @@ EXPORT_SYMBOL_GPL(drm_display_mode_from_videomode);
* This function is expensive and should only be used, if only one mode is to be
* read from DT. To get multiple modes start with of_get_display_timings and
* work with that instead.
+ *
+ * Returns:
+ * 0 on success, a negative errno code when no of videomode node was found.
*/
int of_get_drm_display_mode(struct device_node *np,
struct drm_display_mode *dmode, int index)
@@ -633,7 +655,8 @@ EXPORT_SYMBOL_GPL(of_get_drm_display_mode);
* drm_mode_set_name - set the name on a mode
* @mode: name will be set in this mode
*
- * Set the name of @mode to a standard format.
+ * Set the name of @mode to a standard format which is <hdisplay>x<vdisplay>
+ * with an optional 'i' suffix for interlaced modes.
*/
void drm_mode_set_name(struct drm_display_mode *mode)
{
@@ -648,7 +671,9 @@ EXPORT_SYMBOL(drm_mode_set_name);
/** drm_mode_hsync - get the hsync of a mode
* @mode: mode
*
- * Return @modes's hsync rate in kHz, rounded to the nearest int.
+ * Returns:
+ * @modes's hsync rate in kHz, rounded to the nearest integer. Calculates the
+ * value first if it is not yet set.
*/
int drm_mode_hsync(const struct drm_display_mode *mode)
{
@@ -672,14 +697,9 @@ EXPORT_SYMBOL(drm_mode_hsync);
* drm_mode_vrefresh - get the vrefresh of a mode
* @mode: mode
*
- * Return @mode's vrefresh rate in Hz or calculate it if necessary.
- *
- * FIXME: why is this needed? shouldn't vrefresh be set already?
- *
- * RETURNS:
- * Vertical refresh rate. It will be the result of actual value plus 0.5.
- * If it is 70.288, it will return 70Hz.
- * If it is 59.6, it will return 60Hz.
+ * Returns:
+ * @modes's vrefresh rate in Hz, rounded to the nearest integer. Calculates the
+ * value first if it is not yet set.
*/
int drm_mode_vrefresh(const struct drm_display_mode *mode)
{
@@ -708,11 +728,11 @@ int drm_mode_vrefresh(const struct drm_display_mode *mode)
EXPORT_SYMBOL(drm_mode_vrefresh);
/**
- * drm_mode_set_crtcinfo - set CRTC modesetting parameters
+ * drm_mode_set_crtcinfo - set CRTC modesetting timing parameters
* @p: mode
* @adjust_flags: a combination of adjustment flags
*
- * Setup the CRTC modesetting parameters for @p, adjusting if necessary.
+ * Setup the CRTC modesetting timing parameters for @p, adjusting if necessary.
*
* - The CRTC_INTERLACE_HALVE_V flag can be used to halve vertical timings of
* interlaced modes.
@@ -780,7 +800,6 @@ void drm_mode_set_crtcinfo(struct drm_display_mode *p, int adjust_flags)
}
EXPORT_SYMBOL(drm_mode_set_crtcinfo);
-
/**
* drm_mode_copy - copy the mode
* @dst: mode to overwrite
@@ -807,6 +826,9 @@ EXPORT_SYMBOL(drm_mode_copy);
*
* Just allocate a new mode, copy the existing mode into it, and return
* a pointer to it. Used to create new instances of established modes.
+ *
+ * Returns:
+ * Pointer to duplicated mode on success, NULL on error.
*/
struct drm_display_mode *drm_mode_duplicate(struct drm_device *dev,
const struct drm_display_mode *mode)
@@ -830,7 +852,7 @@ EXPORT_SYMBOL(drm_mode_duplicate);
*
* Check to see if @mode1 and @mode2 are equivalent.
*
- * RETURNS:
+ * Returns:
* True if the modes are equal, false otherwise.
*/
bool drm_mode_equal(const struct drm_display_mode *mode1, const struct drm_display_mode *mode2)
@@ -859,7 +881,7 @@ EXPORT_SYMBOL(drm_mode_equal);
* Check to see if @mode1 and @mode2 are equivalent, but
* don't check the pixel clocks nor the stereo layout.
*
- * RETURNS:
+ * Returns:
* True if the modes are equal, false otherwise.
*/
bool drm_mode_equal_no_clocks_no_stereo(const struct drm_display_mode *mode1,
@@ -890,9 +912,10 @@ EXPORT_SYMBOL(drm_mode_equal_no_clocks_no_stereo);
* @maxX: maximum width
* @maxY: maximum height
*
- * The DRM device (@dev) has size and pitch limits. Here we validate the
- * modes we probed for @dev against those limits and set their status as
- * necessary.
+ * This function is a helper which can be used to validate modes against size
+ * limitations of the DRM device/connector. If a mode is too big its status
+ * memeber is updated with the appropriate validation failure code. The list
+ * itself is not changed.
*/
void drm_mode_validate_size(struct drm_device *dev,
struct list_head *mode_list,
@@ -916,9 +939,10 @@ EXPORT_SYMBOL(drm_mode_validate_size);
* @mode_list: list of modes to check
* @verbose: be verbose about it
*
- * Once mode list generation is complete, a caller can use this routine to
- * remove invalid modes from a mode list. If any of the modes have a
- * status other than %MODE_OK, they are removed from @mode_list and freed.
+ * This helper function can be used to prune a display mode list after
+ * validation has been completed. All modes who's status is not MODE_OK will be
+ * removed from the list, and if @verbose the status code and mode name is also
+ * printed to dmesg.
*/
void drm_mode_prune_invalid(struct drm_device *dev,
struct list_head *mode_list, bool verbose)
@@ -948,7 +972,7 @@ EXPORT_SYMBOL(drm_mode_prune_invalid);
* Compare two modes, given by @lh_a and @lh_b, returning a value indicating
* which is better.
*
- * RETURNS:
+ * Returns:
* Negative if @lh_a is better than @lh_b, zero if they're equivalent, or
* positive if @lh_b is better than @lh_a.
*/
@@ -976,9 +1000,9 @@ static int drm_mode_compare(void *priv, struct list_head *lh_a, struct list_head
/**
* drm_mode_sort - sort mode list
- * @mode_list: list to sort
+ * @mode_list: list of drm_display_mode structures to sort
*
- * Sort @mode_list by favorability, putting good modes first.
+ * Sort @mode_list by favorability, moving good modes to the head of the list.
*/
void drm_mode_sort(struct list_head *mode_list)
{
@@ -992,8 +1016,10 @@ EXPORT_SYMBOL(drm_mode_sort);
*
* This moves the modes from the @connector probed_modes list
* to the actual mode list. It compares the probed mode against the current
- * list and only adds different modes. All modes unverified after this point
- * will be removed by the prune invalid modes.
+ * list and only adds different/new modes.
+ *
+ * This is just a helper functions doesn't validate any modes itself and also
+ * doesn't prune any invalid modes. Callers need to do that themselves.
*/
void drm_mode_connector_list_update(struct drm_connector *connector)
{
@@ -1028,18 +1054,25 @@ void drm_mode_connector_list_update(struct drm_connector *connector)
EXPORT_SYMBOL(drm_mode_connector_list_update);
/**
- * drm_mode_parse_command_line_for_connector - parse command line for connector
- * @mode_option: per connector mode option
- * @connector: connector to parse line for
- * @mode: preallocated mode structure to fill out
+ * drm_mode_parse_command_line_for_connector - parse command line modeline for connector
+ * @mode_option: optional per connector mode option
+ * @connector: connector to parse modeline for
+ * @mode: preallocated drm_cmdline_mode structure to fill out
+ *
+ * This parses @mode_option command line modeline for modes and options to
+ * configure the connector. If @mode_option is NULL the default command line
+ * modeline in fb_mode_option will be parsed instead.
*
- * This parses the connector specific then generic command lines for
- * modes and options to configure the connector.
+ * This uses the same parameters as the fb modedb.c, except for an extra
+ * force-enable, force-enable-digital and force-disable bit at the end:
*
- * This uses the same parameters as the fb modedb.c, except for extra
* <xres>x<yres>[M][R][-<bpp>][@<refresh>][i][m][eDd]
*
- * enable/enable Digital/disable bit at the end
+ * The intermediate drm_cmdline_mode structure is required to store additional
+ * options from the command line modline like the force-enabel/disable flag.
+ *
+ * Returns:
+ * True if a valid modeline has been parsed, false otherwise.
*/
bool drm_mode_parse_command_line_for_connector(const char *mode_option,
struct drm_connector *connector,
@@ -1192,6 +1225,14 @@ done:
}
EXPORT_SYMBOL(drm_mode_parse_command_line_for_connector);
+/**
+ * drm_mode_create_from_cmdline_mode - convert a command line modeline into a DRM display mode
+ * @dev: DRM device to create the new mode for
+ * @cmd: input command line modeline
+ *
+ * Returns:
+ * Pointer to converted mode on success, NULL on error.
+ */
struct drm_display_mode *
drm_mode_create_from_cmdline_mode(struct drm_device *dev,
struct drm_cmdline_mode *cmd)
@@ -162,6 +162,14 @@ struct drm_cmdline_mode {
enum drm_connector_force force;
};
+/**
+ * drm_mode_is_stereo - check for stereo mode flags
+ * @mode: drm_display_mode to check
+ *
+ * Returns:
+ * True if the mode is one of the stereo modes (like side-by-side), false if
+ * not.
+ */
static inline bool drm_mode_is_stereo(const struct drm_display_mode *mode)
{
return mode->flags & DRM_MODE_FLAG_3D_MASK;