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Unverified Commit 1bf4e092 authored by Maxime Ripard's avatar Maxime Ripard
Browse files

drm/modes: Allow to specify rotation and reflection on the commandline 



Rotations and reflections setup are needed in some scenarios to initialise
properly the initial framebuffer. Some drivers already had a bunch of
quirks to deal with this, such as either a private kernel command line
parameter (omapdss) or on the device tree (various panels).

In order to accomodate this, let's create a video mode parameter to deal
with the rotation and reflexion.

Reviewed-by: default avatarNoralf Trønnes <noralf@tronnes.org>
Signed-off-by: default avatarMaxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/777da16e42db757c1f5b414b5ca34507097fed5c.1560783090.git-series.maxime.ripard@bootlin.com
parent 3aeeb13d

Documentation/fb/modedb.txt

+12 −0
Original line number Diff line number Diff line
@@ -51,6 +51,18 @@ To force the VGA output to be enabled and drive a specific mode say: 
Specifying the option multiple times for different ports is possible, e.g.:

    video=LVDS-1:d video=HDMI-1:D



Options can also be passed after the mode, using commas as separator.



       Sample usage: 720x480,rotate=180 - 720x480 mode, rotated by 180 degrees



Valid options are:



  - reflect_x (boolean): Perform an axial symmetry on the X axis

  - reflect_y (boolean): Perform an axial symmetry on the Y axis

  - rotate (integer): Rotate the initial framebuffer by x

    degrees. Valid values are 0, 90, 180 and 270.





***** oOo ***** oOo ***** oOo ***** oOo ***** oOo ***** oOo ***** oOo *****



What is the VESA(TM) Coordinated Video Timings (CVT)?

drivers/gpu/drm/drm_client_modeset.c

+30 −0
Original line number Diff line number Diff line
@@ -824,6 +824,7 @@ bool drm_client_rotation(struct drm_mode_set *modeset, unsigned int *rotation) 
{

	struct drm_connector *connector = modeset->connectors[0];

	struct drm_plane *plane = modeset->crtc->primary;

	struct drm_cmdline_mode *cmdline;

	u64 valid_mask = 0;

	unsigned int i;
@@ -844,6 +845,35 @@ bool drm_client_rotation(struct drm_mode_set *modeset, unsigned int *rotation) 
		*rotation = DRM_MODE_ROTATE_0;

	}



	/**

	 * The panel already defined the default rotation

	 * through its orientation. Whatever has been provided

	 * on the command line needs to be added to that.

	 *

	 * Unfortunately, the rotations are at different bit

	 * indices, so the math to add them up are not as

	 * trivial as they could.

	 *

	 * Reflections on the other hand are pretty trivial to deal with, a

	 * simple XOR between the two handle the addition nicely.

	 */

	cmdline = &connector->cmdline_mode;

	if (cmdline->specified) {

		unsigned int cmdline_rest, panel_rest;

		unsigned int cmdline_rot, panel_rot;

		unsigned int sum_rot, sum_rest;



		panel_rot = ilog2(*rotation & DRM_MODE_ROTATE_MASK);

		cmdline_rot = ilog2(cmdline->rotation_reflection & DRM_MODE_ROTATE_MASK);

		sum_rot = (panel_rot + cmdline_rot) % 4;



		panel_rest = *rotation & ~DRM_MODE_ROTATE_MASK;

		cmdline_rest = cmdline->rotation_reflection & ~DRM_MODE_ROTATE_MASK;

		sum_rest = panel_rest ^ cmdline_rest;



		*rotation = (1 << sum_rot) | sum_rest;

	}



	/*

	 * TODO: support 90 / 270 degree hardware rotation,

	 * depending on the hardware this may require the framebuffer

drivers/gpu/drm/drm_modes.c

+94 −20
Original line number Diff line number Diff line
@@ -1554,6 +1554,71 @@ static int drm_mode_parse_cmdline_res_mode(const char *str, unsigned int length, 
	return 0;

}



static int drm_mode_parse_cmdline_options(char *str, size_t len,

					  struct drm_connector *connector,

					  struct drm_cmdline_mode *mode)

{

	unsigned int rotation = 0;

	char *sep = str;



	while ((sep = strchr(sep, ','))) {

		char *delim, *option;



		option = sep + 1;

		delim = strchr(option, '=');

		if (!delim) {

			delim = strchr(option, ',');



			if (!delim)

				delim = str + len;

		}



		if (!strncmp(option, "rotate", delim - option)) {

			const char *value = delim + 1;

			unsigned int deg;



			deg = simple_strtol(value, &sep, 10);



			/* Make sure we have parsed something */

			if (sep == value)

				return -EINVAL;



			switch (deg) {

			case 0:

				rotation |= DRM_MODE_ROTATE_0;

				break;



			case 90:

				rotation |= DRM_MODE_ROTATE_90;

				break;



			case 180:

				rotation |= DRM_MODE_ROTATE_180;

				break;



			case 270:

				rotation |= DRM_MODE_ROTATE_270;

				break;



			default:

				return -EINVAL;

			}

		} else if (!strncmp(option, "reflect_x", delim - option)) {

			rotation |= DRM_MODE_REFLECT_X;

			sep = delim;

		} else if (!strncmp(option, "reflect_y", delim - option)) {

			rotation |= DRM_MODE_REFLECT_Y;

			sep = delim;

		} else {

			return -EINVAL;

		}

	}



	mode->rotation_reflection = rotation;



	return 0;

}



/**

 * drm_mode_parse_command_line_for_connector - parse command line modeline for connector

 * @mode_option: optional per connector mode option
@@ -1569,6 +1634,10 @@ static int drm_mode_parse_cmdline_res_mode(const char *str, unsigned int length, 
 *

 *	<xres>x<yres>[M][R][-<bpp>][@<refresh>][i][m][eDd]

 *

 * Additionals options can be provided following the mode, using a comma to

 * separate each option. Valid options can be found in

 * Documentation/fb/modedb.txt.

 *

 * The intermediate drm_cmdline_mode structure is required to store additional

 * options from the command line modline like the force-enable/disable flag.

 *
@@ -1581,9 +1650,10 @@ bool drm_mode_parse_command_line_for_connector(const char *mode_option, 
{

	const char *name;

	bool named_mode = false, parse_extras = false;

	unsigned int bpp_off = 0, refresh_off = 0;

	unsigned int bpp_off = 0, refresh_off = 0, options_off = 0;

	unsigned int mode_end = 0;

	char *bpp_ptr = NULL, *refresh_ptr = NULL, *extra_ptr = NULL;

	char *options_ptr = NULL;

	char *bpp_end_ptr = NULL, *refresh_end_ptr = NULL;

	int ret;
@@ -1632,13 +1702,18 @@ bool drm_mode_parse_command_line_for_connector(const char *mode_option, 
		mode->refresh_specified = true;

	}



	/* Locate the start of named options */

	options_ptr = strchr(name, ',');

	if (options_ptr)

		options_off = options_ptr - name;



	/* Locate the end of the name / resolution, and parse it */

	if (bpp_ptr && refresh_ptr) {

		mode_end = min(bpp_off, refresh_off);

	} else if (bpp_ptr) {

	if (bpp_ptr) {

		mode_end = bpp_off;

	} else if (refresh_ptr) {

		mode_end = refresh_off;

	} else if (options_ptr) {

		mode_end = options_off;

	} else {

		mode_end = strlen(name);

		parse_extras = true;
@@ -1680,25 +1755,24 @@ bool drm_mode_parse_command_line_for_connector(const char *mode_option, 
	else if (refresh_ptr)

		extra_ptr = refresh_end_ptr;



	if (extra_ptr) {

		if (!named_mode) {

	if (extra_ptr &&

	    extra_ptr != options_ptr) {

		int len = strlen(name) - (extra_ptr - name);



		ret = drm_mode_parse_cmdline_extra(extra_ptr, len,

						   connector, mode);

		if (ret)

			return false;

		} else {

			int remaining = strlen(name) - (extra_ptr - name);

	}



			/*

			 * We still have characters to process, while

			 * we shouldn't have any

			 */

			if (remaining > 0)

	if (options_ptr) {

		int len = strlen(name) - (options_ptr - name);



		ret = drm_mode_parse_cmdline_options(options_ptr, len,

						     connector, mode);

		if (ret)

			return false;

	}

	}



	return true;

}

include/drm/drm_connector.h

+10 −0
Original line number Diff line number Diff line
@@ -1025,6 +1025,16 @@ struct drm_cmdline_mode { 
	 * state to one of the DRM_FORCE_* values.

	 */

	enum drm_connector_force force;



	/**

	 * @rotation_reflection:

	 *

	 * Initial rotation and reflection of the mode setup from the

	 * command line. See DRM_MODE_ROTATE_* and

	 * DRM_MODE_REFLECT_*. The only rotations supported are

	 * DRM_MODE_ROTATE_0 and DRM_MODE_ROTATE_180.

	 */

	unsigned int rotation_reflection;

};



/**