drm/fb: add more correct 8/16/24/32 bpp fb support.

The previous patches had some unwanted side effects, I've fixed
the lack of 32bpp working, and fixed up 16bpp so it should also work.

this also adds the interface to allow the driver to set a preferred
console depth so for example low memory rn50 can set it to 8bpp.
It also catches 24bpp on cards that can't do it and forces 32bpp.

Tested on r100/r600/i945.

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

1 files changed, 62 insertions, 33 deletions

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 3746bd2f0f0..23dc9c115fd 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -454,6 +454,54 @@ out_free:
 }
 EXPORT_SYMBOL(drm_fb_helper_init_crtc_count);
 
+static void setcolreg(struct drm_crtc *crtc, u16 red, u16 green,
+		     u16 blue, u16 regno, struct fb_info *info)
+{
+	struct drm_fb_helper *fb_helper = info->par;
+	struct drm_framebuffer *fb = fb_helper->fb;
+	int pindex;
+
+	pindex = regno;
+
+	if (fb->bits_per_pixel == 16) {
+		pindex = regno << 3;
+
+		if (fb->depth == 16 && regno > 63)
+			return;
+		if (fb->depth == 15 && regno > 31)
+			return;
+
+		if (fb->depth == 16) {
+			u16 r, g, b;
+			int i;
+			if (regno < 32) {
+				for (i = 0; i < 8; i++)
+					fb_helper->funcs->gamma_set(crtc, red,
+						green, blue, pindex + i);
+			}
+
+			fb_helper->funcs->gamma_get(crtc, &r,
+						    &g, &b,
+						    pindex >> 1);
+
+			for (i = 0; i < 4; i++)
+				fb_helper->funcs->gamma_set(crtc, r,
+							    green, b,
+							    (pindex >> 1) + i);
+		}
+	}
+
+	if (fb->depth != 16)
+		fb_helper->funcs->gamma_set(crtc, red, green, blue, pindex);
+
+	if (regno < 16 && info->fix.visual == FB_VISUAL_DIRECTCOLOR) {
+		((u32 *) fb->pseudo_palette)[regno] =
+			(regno << info->var.red.offset) |
+			(regno << info->var.green.offset) |
+			(regno << info->var.blue.offset);
+	}
+}
+
 int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
 {
 	struct drm_fb_helper *fb_helper = info->par;
@@ -488,7 +536,7 @@ int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
 			if (transp)
 				htransp = *transp++;
 
-			fb_helper->funcs->gamma_set(crtc, hred, hgreen, hblue, start++);
+			setcolreg(crtc, hred, hgreen, hblue, start++, info);
 		}
 		crtc_funcs->load_lut(crtc);
 	}
@@ -508,9 +556,11 @@ int drm_fb_helper_setcolreg(unsigned regno,
 	struct drm_crtc *crtc;
 	int i;
 
-	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
-		struct drm_framebuffer *fb = fb_helper->fb;
+	if (regno > 255)
+		return 1;
 
+	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
+		struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 		for (i = 0; i < fb_helper->crtc_count; i++) {
 			if (crtc->base.id == fb_helper->crtc_info[i].crtc_id)
 				break;
@@ -518,36 +568,9 @@ int drm_fb_helper_setcolreg(unsigned regno,
 		if (i == fb_helper->crtc_count)
 			continue;
 
-		if (regno > 255)
-			return 1;
-
-		if (fb->depth == 8) {
-			fb_helper->funcs->gamma_set(crtc, red, green, blue, regno);
-			return 0;
-		}
 
-		if (regno < 16) {
-			u32 *pal = fb->pseudo_palette;
-			switch (fb->depth) {
-			case 15:
-				pal[regno] = ((red & 0xf800) >> 1) |
-					((green & 0xf800) >>  6) |
-					((blue & 0xf800) >> 11);
-				break;
-			case 16:
-				pal[regno] = (red & 0xf800) |
-					((green & 0xfc00) >>  5) |
-					((blue  & 0xf800) >> 11);
-				break;
-			case 24:
-			case 32:
-				pal[regno] =
-					(((red >> 8) & 0xff) << info->var.red.offset) |
-					(((green >> 8) & 0xff) << info->var.green.offset) |
-					(((blue >> 8) & 0xff) << info->var.blue.offset);
-				break;
-			}
-		}
+		setcolreg(crtc, red, green, blue, regno, info);
+		crtc_funcs->load_lut(crtc);
 	}
 	return 0;
 }
@@ -717,6 +740,7 @@ int drm_fb_helper_pan_display(struct fb_var_screeninfo *var,
 EXPORT_SYMBOL(drm_fb_helper_pan_display);
 
 int drm_fb_helper_single_fb_probe(struct drm_device *dev,
+				  int preferred_bpp,
 				  int (*fb_create)(struct drm_device *dev,
 						   uint32_t fb_width,
 						   uint32_t fb_height,
@@ -739,6 +763,11 @@ int drm_fb_helper_single_fb_probe(struct drm_device *dev,
 	struct drm_fb_helper *fb_helper;
 	uint32_t surface_depth = 24, surface_bpp = 32;
 
+	/* if driver picks 8 or 16 by default use that
+	   for both depth/bpp */
+	if (preferred_bpp != surface_bpp) {
+		surface_depth = surface_bpp = preferred_bpp;
+	}
 	/* first up get a count of crtcs now in use and new min/maxes width/heights */
 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 		struct drm_fb_helper_connector *fb_help_conn = connector->fb_helper_private;
@@ -899,7 +928,7 @@ void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
 {
 	info->fix.type = FB_TYPE_PACKED_PIXELS;
 	info->fix.visual = depth == 8 ? FB_VISUAL_PSEUDOCOLOR :
-		FB_VISUAL_TRUECOLOR;
+		FB_VISUAL_DIRECTCOLOR;
 	info->fix.type_aux = 0;
 	info->fix.xpanstep = 1; /* doing it in hw */
 	info->fix.ypanstep = 1; /* doing it in hw */