Thread (28 messages) 28 messages, 8 authors, 2019-08-23
STALE2495d

[PATCH v5 07/12] drm/modes: Allow to specify rotation and reflection on the commandline

From: Maxime Ripard <hidden>
Date: 2019-06-17 14:56:34
Also in: dri-devel
Subsystem: documentation, drm drivers, drm drivers and misc gpu patches, framebuffer layer, the rest · Maintainers: Jonathan Corbet, David Airlie, Simona Vetter, Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, Helge Deller, Linus Torvalds

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.

Signed-off-by: Maxime Ripard <redacted>
---
 Documentation/fb/modedb.rst          |  11 +++-
 drivers/gpu/drm/drm_client_modeset.c |  30 +++++++-
 drivers/gpu/drm/drm_modes.c          | 114 +++++++++++++++++++++++-----
 include/drm/drm_connector.h          |  10 ++-
 4 files changed, 145 insertions(+), 20 deletions(-)
diff --git a/Documentation/fb/modedb.rst b/Documentation/fb/modedb.rst
index 3c2397293977..3e8a6f79dcd7 100644
--- a/Documentation/fb/modedb.rst
+++ b/Documentation/fb/modedb.rst
@@ -53,6 +53,17 @@ 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 symetry on the X axis
+  - reflect_y (boolean): Perform an axial symetry on the Y axis
+  - rotate (integer): Rotate the initial framebuffer by x
+    degrees. Valid values are 0, 90, 180 and 270.
+
 -----------------------------------------------------------------------------
 
 What is the VESA(TM) Coordinated Video Timings (CVT)?
diff --git a/drivers/gpu/drm/drm_client_modeset.c b/drivers/gpu/drm/drm_client_modeset.c
index 33d4988f22ae..e95fceac8f8b 100644
--- a/drivers/gpu/drm/drm_client_modeset.c
+++ b/drivers/gpu/drm/drm_client_modeset.c
@@ -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
diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index 429d3be17800..dc6d11292685 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -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;
@@ -1680,24 +1755,23 @@ 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) {
-			int len = strlen(name) - (extra_ptr - name);
+	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);
+		ret = drm_mode_parse_cmdline_extra(extra_ptr, len,
+						   connector, mode);
+		if (ret)
+			return false;
+	}
 
-			/*
-			 * We still have characters to process, while
-			 * we shouldn't have any
-			 */
-			if (remaining > 0)
-				return false;
-		}
+	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;
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index cdf2fb910010..8eebe0432c73 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -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;
 };
 
 /**
-- 
git-series 0.9.1

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