drm/kms: start adding command line interface using fb.

[note this requires an fb patch posted to linux-fbdev-devel already]

This uses the normal video= command line option to control the kms
output setup at boot time. It is used to override the autodetection
done by kms.

video= normally takes a framebuffer as the first parameter, in kms
it will take a connector name, DVI-I-1, or LVDS-1 etc. If no output
connector is specified the mode string will apply to all connectors.

The mode specification used will match down the probed modes, and if
no mode is found it will add a CVT mode that matches.

video=1024x768 - all connectors match a 1024x768 mode or add a CVT on
video=VGA-1:1024x768, VGA-1 connector gets mode only.

The same strings as used in current fb modedb.c are used, except I've
added three more letters, e, D, d, e = enable, D = enable Digital,
d = disable, which allow a connector to be forced into a certain state.

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 74 insertions, 5 deletions

diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
index fe8697447f32..82fd6e82450f 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -32,6 +32,7 @@
 #include "drmP.h"
 #include "drm_crtc.h"
 #include "drm_crtc_helper.h"
+#include "drm_fb_helper.h"
 
 static void drm_mode_validate_flag(struct drm_connector *connector,
 				   int flags)
@@ -90,7 +91,15 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
 	list_for_each_entry_safe(mode, t, &connector->modes, head)
 		mode->status = MODE_UNVERIFIED;
 
-	connector->status = connector->funcs->detect(connector);
+	if (connector->force) {
+		if (connector->force == DRM_FORCE_ON)
+			connector->status = connector_status_connected;
+		else
+			connector->status = connector_status_disconnected;
+		if (connector->funcs->force)
+			connector->funcs->force(connector);
+	} else
+		connector->status = connector->funcs->detect(connector);
 
 	if (connector->status == connector_status_disconnected) {
 		DRM_DEBUG_KMS("%s is disconnected\n",
@@ -267,6 +276,56 @@ static struct drm_display_mode *drm_has_preferred_mode(struct drm_connector *con
 	return NULL;
 }
 
+static bool drm_has_cmdline_mode(struct drm_connector *connector)
+{
+	struct drm_fb_helper_connector *fb_help_conn = connector->fb_helper_private;
+	struct drm_fb_helper_cmdline_mode *cmdline_mode = &fb_help_conn->cmdline_mode;
+	return cmdline_mode->specified;
+}
+
+static struct drm_display_mode *drm_pick_cmdline_mode(struct drm_connector *connector, int width, int height)
+{
+	struct drm_fb_helper_connector *fb_help_conn = connector->fb_helper_private;
+	struct drm_fb_helper_cmdline_mode *cmdline_mode = &fb_help_conn->cmdline_mode;
+	struct drm_display_mode *mode = NULL;
+
+	if (cmdline_mode->specified == false)
+		return mode;
+
+	/* attempt to find a matching mode in the list of modes
+	 *  we have gotten so far, if not add a CVT mode that conforms
+	 */
+	if (cmdline_mode->rb || cmdline_mode->margins)
+		goto create_mode;
+
+	list_for_each_entry(mode, &connector->modes, head) {
+		/* check width/height */
+		if (mode->hdisplay != cmdline_mode->xres ||
+		    mode->vdisplay != cmdline_mode->yres)
+			continue;
+
+		if (cmdline_mode->refresh_specified) {
+			if (mode->vrefresh != cmdline_mode->refresh)
+				continue;
+		}
+
+		if (cmdline_mode->interlace) {
+			if (!(mode->flags & DRM_MODE_FLAG_INTERLACE))
+				continue;
+		}
+		return mode;
+	}
+
+create_mode:
+	mode = drm_cvt_mode(connector->dev, cmdline_mode->xres,
+			    cmdline_mode->yres,
+			    cmdline_mode->refresh_specified ? cmdline_mode->refresh : 60,
+			    cmdline_mode->rb, cmdline_mode->interlace,
+			    cmdline_mode->margins);
+	list_add(&mode->head, &connector->modes);
+	return mode;
+}
+
 static bool drm_connector_enabled(struct drm_connector *connector, bool strict)
 {
 	bool enable;
@@ -317,10 +376,16 @@ static bool drm_target_preferred(struct drm_device *dev,
 			continue;
 		}
 
-		DRM_DEBUG_KMS("looking for preferred mode on connector %d\n",
-			  connector->base.id);
+		DRM_DEBUG_KMS("looking for cmdline mode on connector %d\n",
+			      connector->base.id);
 
-		modes[i] = drm_has_preferred_mode(connector, width, height);
+		/* got for command line mode first */
+		modes[i] = drm_pick_cmdline_mode(connector, width, height);
+		if (!modes[i]) {
+			DRM_DEBUG_KMS("looking for preferred mode on connector %d\n",
+				      connector->base.id);
+			modes[i] = drm_has_preferred_mode(connector, width, height);
+		}
 		/* No preferred modes, pick one off the list */
 		if (!modes[i] && !list_empty(&connector->modes)) {
 			list_for_each_entry(modes[i], &connector->modes, head)
@@ -369,6 +434,8 @@ static int drm_pick_crtcs(struct drm_device *dev,
 	my_score = 1;
 	if (connector->status == connector_status_connected)
 		my_score++;
+	if (drm_has_cmdline_mode(connector))
+		my_score++;
 	if (drm_has_preferred_mode(connector, width, height))
 		my_score++;
 
@@ -943,6 +1010,8 @@ bool drm_helper_initial_config(struct drm_device *dev)
 {
 	int count = 0;
 
+	drm_fb_helper_parse_command_line(dev);
+
 	count = drm_helper_probe_connector_modes(dev,
 						 dev->mode_config.max_width,
 						 dev->mode_config.max_height);
@@ -950,7 +1019,7 @@ bool drm_helper_initial_config(struct drm_device *dev)
 	/*
 	 * we shouldn't end up with no modes here.
 	 */
-	WARN(!count, "Connected connector with 0 modes\n");
+	WARN(!count, "No connectors reported connected with modes\n");
 
 	drm_setup_crtcs(dev);