[PATCH v3 3/6] drm/modes: Allow to specify rotation and reflection on the commandline

[Maxime Ripard <maxime.ripard@bootlin.com>]

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 <maxime.ripard@bootlin.com>
---
 drivers/gpu/drm/drm_client_modeset.c |  10 +++-
 drivers/gpu/drm/drm_modes.c          | 110 ++++++++++++++++++++++------
 include/drm/drm_connector.h          |   9 ++-
 3 files changed, 109 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/drm_client_modeset.c b/drivers/gpu/drm/drm_client_modeset.c
index f2869c82510c..15145d2c86d5 100644
--- a/drivers/gpu/drm/drm_client_modeset.c
+++ b/drivers/gpu/drm/drm_client_modeset.c
@@ -823,6 +823,7 @@ EXPORT_SYMBOL(drm_client_modeset_probe);
 bool drm_client_panel_rotation(struct drm_mode_set *modeset, unsigned int *rotation)
 {
 	struct drm_connector *connector = modeset->connectors[0];
+	struct drm_cmdline_mode *cmdline;
 	struct drm_plane *plane = modeset->crtc->primary;
 	u64 valid_mask = 0;
 	unsigned int i;
@@ -844,6 +845,15 @@ bool drm_client_panel_rotation(struct drm_mode_set *modeset, unsigned int *rotat
 		*rotation = DRM_MODE_ROTATE_0;
 	}
 
+	/**
+	 * We want the rotation on the command line to overwrite
+	 * whatever comes from the panel.
+	 */
+	cmdline = &connector->cmdline_mode;
+	if (cmdline->specified &&
+	    cmdline->rotation != DRM_MODE_ROTATE_0)
+		*rotation = cmdline->rotation;
+
 	/*
 	 * 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 9613c1a28487..ac8d70b92b62 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -1531,6 +1531,71 @@ 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 = rotation;
+
+	return 0;
+}
+
 /**
  * drm_mode_parse_command_line_for_connector - parse command line modeline for connector
  * @mode_option: optional per connector mode option
@@ -1558,9 +1623,10 @@ 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;
 
@@ -1601,13 +1667,18 @@ 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;
@@ -1649,24 +1720,23 @@ 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 06aa3b9cb920..6f57c1a3afff 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -908,6 +908,15 @@ struct drm_cmdline_mode {
 	bool cvt;
 	bool margins;
 	enum drm_connector_force force;
+
+	/**
+	 * @rotation:
+	 *
+	 * Initial rotation of the mode setup from the command line.
+	 * See DRM_MODE_ROTATE_*. Only DRM_MODE_ROTATE_0 and
+	 * DRM_MODE_ROTATE_180 are supported at the moment.
+	 */
+	unsigned int rotation;
 };
 
 /**
-- 
git-series 0.9.1

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