video: tegra: dc: support global fbdev gamma table

Add support to set a global gamma correction table via fbdev cmap
API. The 3 Tegra DC windows have their own local gamma tables, which
can either override or alter the global table.

Bug 868060

Change-Id: I0be1c5e4afa8fd8c010b772c7808c883c0848ab4
Reviewed-on: http://git-master/r/60201
Reviewed-by: Varun Colbert <vcolbert@nvidia.com>
Tested-by: Varun Colbert <vcolbert@nvidia.com>

Rebase-Id: R7e613b1c8ac469242172bd81db9dfba25176e0c3

3 files changed, 77 insertions, 39 deletions

diff --git a/drivers/video/tegra/dc/dc.c b/drivers/video/tegra/dc/dc.c
index b1c441390ce4..4f8da4e4735e 100644
--- a/drivers/video/tegra/dc/dc.c
+++ b/drivers/video/tegra/dc/dc.c
@@ -672,29 +672,49 @@ static void tegra_dc_init_lut_defaults(struct tegra_dc_lut *lut)
 		lut->r[i] = lut->g[i] = lut->b[i] = (u8)i;
 }
 
-static int tegra_dc_lut_is_defaults(struct tegra_dc_lut *lut)
+static int tegra_dc_loop_lut(struct tegra_dc *dc,
+			     struct tegra_dc_win *win,
+			     int(*lambda)(struct tegra_dc *dc, int i, u32 rgb))
 {
-	unsigned int i;
-	for (i = 0; i < 256; i++)
-		if ((lut->r[i] != i) || (lut->g[i] != i) || (lut->b[i] != i))
+	struct tegra_dc_lut *lut = &win->lut;
+	struct tegra_dc_lut *global_lut = &dc->fb_lut;
+	int i;
+	for (i = 0; i < 256; i++) {
+
+		u32 r = (u32)lut->r[i];
+		u32 g = (u32)lut->g[i];
+		u32 b = (u32)lut->b[i];
+
+		if (!(win->ppflags & TEGRA_WIN_PPFLAG_CP_FBOVERRIDE)) {
+			r = (u32)global_lut->r[r];
+			g = (u32)global_lut->g[g];
+			b = (u32)global_lut->b[b];
+		}
+
+		if (!lambda(dc, i, r | (g<<8) | (b<<16)))
 			return 0;
+	}
 	return 1;
 }
 
-static void tegra_dc_set_lut(struct tegra_dc *dc, struct tegra_dc_win* win)
+static int tegra_dc_lut_isdefaults_lambda(struct tegra_dc *dc, int i, u32 rgb)
 {
-	unsigned int i;
-	unsigned long val;
-	struct tegra_dc_lut *lut = &win->lut;
+	if (rgb != (i | (i<<8) | (i<<16)))
+		return 0;
+	return 1;
+}
 
-	for (i = 0; i < 256; i++) {
-		u32 rgb = ((u32)lut->r[i]) |
-			  ((u32)lut->g[i]<<8) |
-			  ((u32)lut->b[i]<<16);
-		tegra_dc_writel(dc, rgb, DC_WIN_COLOR_PALETTE(i));
-	}
+static int tegra_dc_set_lut_setreg_lambda(struct tegra_dc *dc, int i, u32 rgb)
+{
+	tegra_dc_writel(dc, rgb, DC_WIN_COLOR_PALETTE(i));
+	return 1;
+}
+
+static void tegra_dc_set_lut(struct tegra_dc *dc, struct tegra_dc_win* win)
+{
+	unsigned long val = tegra_dc_readl(dc, DC_WIN_WIN_OPTIONS);
 
-	val = tegra_dc_readl(dc, DC_WIN_WIN_OPTIONS);
+	tegra_dc_loop_lut(dc, win, tegra_dc_set_lut_setreg_lambda);
 
 	if (win->ppflags & TEGRA_WIN_PPFLAG_CP_ENABLE)
 		val |= CP_ENABLE;
@@ -704,7 +724,7 @@ static void tegra_dc_set_lut(struct tegra_dc *dc, struct tegra_dc_win* win)
 	tegra_dc_writel(dc, val, DC_WIN_WIN_OPTIONS);
 }
 
-int tegra_dc_update_lut(struct tegra_dc *dc, int win_idx, int fboveride)
+static int tegra_dc_update_winlut(struct tegra_dc *dc, int win_idx, int fbovr)
 {
 	struct tegra_dc_win *win = &dc->windows[win_idx];
 
@@ -715,16 +735,16 @@ int tegra_dc_update_lut(struct tegra_dc *dc, int win_idx, int fboveride)
 		return -EFAULT;
 	}
 
-	if (!tegra_dc_lut_is_defaults(&win->lut))
+	if (fbovr > 0)
+		win->ppflags |= TEGRA_WIN_PPFLAG_CP_FBOVERRIDE;
+	else if (fbovr == 0)
+		win->ppflags &= ~TEGRA_WIN_PPFLAG_CP_FBOVERRIDE;
+
+	if (!tegra_dc_loop_lut(dc, win, tegra_dc_lut_isdefaults_lambda))
 		win->ppflags |= TEGRA_WIN_PPFLAG_CP_ENABLE;
 	else
 		win->ppflags &= ~TEGRA_WIN_PPFLAG_CP_ENABLE;
 
-	if (fboveride)
-		win->ppflags |= TEGRA_WIN_PPFLAG_CP_FBOVERRIDE;
-	else
-		win->ppflags &= ~TEGRA_WIN_PPFLAG_CP_FBOVERRIDE;
-
 	tegra_dc_writel(dc, WINDOW_A_SELECT << win_idx,
 			DC_CMD_DISPLAY_WINDOW_HEADER);
 
@@ -734,6 +754,20 @@ int tegra_dc_update_lut(struct tegra_dc *dc, int win_idx, int fboveride)
 
 	return 0;
 }
+
+int tegra_dc_update_lut(struct tegra_dc *dc, int win_idx, int fboveride)
+{
+	if (win_idx > -1)
+		return tegra_dc_update_winlut(dc, win_idx, fboveride);
+
+	for (win_idx = 0; win_idx < DC_N_WINDOWS; win_idx++) {
+		int err = tegra_dc_update_winlut(dc, win_idx, fboveride);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
 EXPORT_SYMBOL(tegra_dc_update_lut);
 
 static void tegra_dc_set_scaling_filter(struct tegra_dc *dc)
@@ -2656,6 +2690,8 @@ static int tegra_dc_probe(struct nvhost_device *ndev)
 #endif
 	INIT_WORK(&dc->vblank_work, tegra_dc_vblank);
 
+	tegra_dc_init_lut_defaults(&dc->fb_lut);
+
 	dc->n_windows = DC_N_WINDOWS;
 	for (i = 0; i < dc->n_windows; i++) {
 		struct tegra_dc_win *win = &dc->windows[i];
diff --git a/drivers/video/tegra/dc/dc_priv.h b/drivers/video/tegra/dc/dc_priv.h
index 5eaa8be7dafd..83f26b8dd543 100644
--- a/drivers/video/tegra/dc/dc_priv.h
+++ b/drivers/video/tegra/dc/dc_priv.h
@@ -132,6 +132,7 @@ struct tegra_dc {
 #ifdef CONFIG_DEBUG_FS
 	struct dentry			*debugdir;
 #endif
+	struct tegra_dc_lut		fb_lut;
 };
 
 static inline void tegra_dc_io_start(struct tegra_dc *dc)
diff --git a/drivers/video/tegra/fb.c b/drivers/video/tegra/fb.c
index 7b01f1ef72a2..44be01013beb 100644
--- a/drivers/video/tegra/fb.c
+++ b/drivers/video/tegra/fb.c
@@ -146,27 +146,28 @@ static int tegra_fb_set_par(struct fb_info *info)
 	return 0;
 }
 
-static int tegra_fb_setcolreg(unsigned regno, unsigned red, unsigned green,
-	unsigned blue, unsigned transp, struct fb_info *info)
+static int tegra_fb_setcmap(struct fb_cmap *cmap, struct fb_info *info)
 {
-	struct fb_var_screeninfo *var = &info->var;
+	struct tegra_fb_info *tegra_fb = info->par;
+	struct tegra_dc *dc = tegra_fb->win->dc;
+	int i;
+	u16 *red = cmap->red;
+	u16 *green = cmap->green;
+	u16 *blue = cmap->blue;
+	int start = cmap->start;
+
+	if (((unsigned)start > 255) || ((start + cmap->len) > 255))
+		return -EINVAL;
 
 	if (info->fix.visual == FB_VISUAL_TRUECOLOR ||
 	    info->fix.visual == FB_VISUAL_DIRECTCOLOR) {
-		u32 v;
-
-		if (regno >= 16)
-			return -EINVAL;
-
-		red = (red >> (16 - info->var.red.length));
-		green = (green >> (16 - info->var.green.length));
-		blue = (blue >> (16 - info->var.blue.length));
-
-		v = (red << var->red.offset) |
-			(green << var->green.offset) |
-			(blue << var->blue.offset);
+		for (i = 0; i < cmap->len; i++) {
+			dc->fb_lut.r[start+i] = *red++ >> 8;
+			dc->fb_lut.g[start+i] = *green++ >> 8;
+			dc->fb_lut.b[start+i] = *blue++ >> 8;
+		}
 
-		((u32 *)info->pseudo_palette)[regno] = v;
+		tegra_dc_update_lut(dc, -1, -1);
 	}
 
 	return 0;
@@ -302,7 +303,7 @@ static struct fb_ops tegra_fb_ops = {
 	.owner = THIS_MODULE,
 	.fb_check_var = tegra_fb_check_var,
 	.fb_set_par = tegra_fb_set_par,
-	.fb_setcolreg = tegra_fb_setcolreg,
+	.fb_setcmap = tegra_fb_setcmap,
 	.fb_blank = tegra_fb_blank,
 	.fb_pan_display = tegra_fb_pan_display,
 	.fb_fillrect = tegra_fb_fillrect,