MLK-13715-2 video: mxsfb: add global alpha mode for overlay fb

Add global alpha mode for overlay framebuffer when the
overlay fb has no alpha channel, which means set a fix
alpha value which is used during the alpha blending
between AS and framebuffer.

Signed-off-by: Fancy Fang <chen.fang@nxp.com>

diff --git a/drivers/video/fbdev/mxsfb.c b/drivers/video/fbdev/mxsfb.c
index 1237997..1177ce9 100644 (file)
--- a/drivers/video/fbdev/mxsfb.c
+++ b/drivers/video/fbdev/mxsfb.c
@@ -219,6 +219,7 @@ struct mxsfb_layer {
        int                     registered;
        uint32_t                usage;
        int                     blank_state;
+       uint32_t                global_alpha;
 
        struct mxsfb_layer_ops  *ops;
 
@@ -1588,7 +1589,7 @@ static void overlayfb_disable(struct mxsfb_layer *ofb)
 static void overlayfb_setup(struct mxsfb_layer *ofb)
 {
        uint32_t as_next_buf, as_ctrl = 0;
-       uint8_t format, alpha_ctrl;
+       uint8_t format, alpha_ctrl, global_alpha_en = 0;
        struct mxsfb_info *fbi = ofb->fbi;
        struct fb_var_screeninfo *var = &ofb->ol_fb->var;
 
@@ -1596,11 +1597,15 @@ static void overlayfb_setup(struct mxsfb_layer *ofb)
        as_next_buf = ofb->video_mem_phys;
        writel(as_next_buf, fbi->base + LCDC_AS_NEXT_BUF);
 
+       /* clear the LCDC_AS_CTRL */
+       writel(0x0, fbi->base + LCDC_AS_CTRL);
+
        switch (var->grayscale) {
        case 0: /* color */
                switch (var->bits_per_pixel) {
                case 16: /* RGB565 */
                        format = 0xE;
+                       global_alpha_en = 1;
                        break;
                case 32: /* ARGB8888 */
                        format = 0x0;
@@ -1618,6 +1623,7 @@ static void overlayfb_setup(struct mxsfb_layer *ofb)
                        break;
                case V4L2_PIX_FMT_XRGB32:
                        format = 0x4;
+                       global_alpha_en = 1;
                        break;
                case V4L2_PIX_FMT_ARGB555:
                        format = 0x8;
@@ -1627,12 +1633,15 @@ static void overlayfb_setup(struct mxsfb_layer *ofb)
                        break;
                case V4L2_PIX_FMT_RGB555:
                        format = 0xC;
+                       global_alpha_en = 1;
                        break;
                case V4L2_PIX_FMT_RGB444:
                        format = 0xD;
+                       global_alpha_en = 1;
                        break;
                case V4L2_PIX_FMT_RGB565:
                        format = 0xE;
+                       global_alpha_en = 1;
                        break;
                default:
                        return;
@@ -1641,9 +1650,11 @@ static void overlayfb_setup(struct mxsfb_layer *ofb)
        }
        as_ctrl |= ((format & 0xf) << 4);
 
-       /*XXX Only support embbeded alpha mode first */
-       alpha_ctrl = ALPHA_CTRL_EMBEDDED;
+       alpha_ctrl = global_alpha_en ? ALPHA_CTRL_OVERRIDE :
+                                      ALPHA_CTRL_EMBEDDED;
        as_ctrl |= ((alpha_ctrl & 0x3) << 1);
+       if (global_alpha_en)
+               as_ctrl |= ((ofb->global_alpha & 0xff) << 8);
 
        writel(as_ctrl, fbi->base + LCDC_AS_CTRL);
 }
@@ -1894,6 +1905,7 @@ static void init_mxsfb_overlay(struct mxsfb_info *fbi,
        ofb->ops = &ofb_ops;
        ofb->usage = 0;
        ofb->blank_state = -1;
+       ofb->global_alpha = 255;
        ofb->fbi = fbi;
 }