video: s3c-fb: add video clock running at data under-flow

This patch adds video clock running at data under-flow.
It means that the pixel clock is continuously provided
to lcd module, even when under-run occurs.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>

1 files changed, 23 insertions, 0 deletions

diff --git a/drivers/video/s3c-fb.c b/drivers/video/s3c-fb.c
index 9af6c1849c24..e22bf9ddf287 100644
--- a/drivers/video/s3c-fb.c
+++ b/drivers/video/s3c-fb.c
@@ -84,6 +84,7 @@ struct s3c_fb;
  * @has_shadowcon: Set if has SHADOWCON register.
  * @has_blendcon: Set if has BLENDCON register.
  * @has_clksel: Set if VIDCON0 register has CLKSEL bit.
+ * @has_fixvclk: Set if VIDCON1 register has FIXVCLK bits.
  */
 struct s3c_fb_variant {
         unsigned int    is_2443:1;
@@ -103,6 +104,7 @@ struct s3c_fb_variant {
         unsigned int    has_shadowcon:1;
         unsigned int    has_blendcon:1;
         unsigned int    has_clksel:1;
+        unsigned int    has_fixvclk:1;
 };
 
 /**
@@ -1358,6 +1360,7 @@ static int __devinit s3c_fb_probe(struct platform_device *pdev)
         struct resource *res;
         int win;
         int ret = 0;
+        u32 reg;
 
         platid = platform_get_device_id(pdev);
         fbdrv = (struct s3c_fb_driverdata *)platid->driver_data;
@@ -1448,6 +1451,14 @@ static int __devinit s3c_fb_probe(struct platform_device *pdev)
 
         writel(pd->vidcon1, sfb->regs + VIDCON1);
 
+        /* set video clock running at under-run */
+        if (sfb->variant.has_fixvclk) {
+                reg = readl(sfb->regs + VIDCON1);
+                reg &= ~VIDCON1_VCLK_MASK;
+                reg |= VIDCON1_VCLK_RUN;
+                writel(reg, sfb->regs + VIDCON1);
+        }
+
         /* zero all windows before we do anything */
 
         for (win = 0; win < fbdrv->variant.nr_windows; win++)
@@ -1571,6 +1582,7 @@ static int s3c_fb_resume(struct device *dev)
         struct s3c_fb_platdata *pd = sfb->pdata;
         struct s3c_fb_win *win;
         int win_no;
+        u32 reg;
 
         clk_enable(sfb->bus_clk);
 
@@ -1581,6 +1593,14 @@ static int s3c_fb_resume(struct device *dev)
         pd->setup_gpio();
         writel(pd->vidcon1, sfb->regs + VIDCON1);
 
+        /* set video clock running at under-run */
+        if (sfb->variant.has_fixvclk) {
+                reg = readl(sfb->regs + VIDCON1);
+                reg &= ~VIDCON1_VCLK_MASK;
+                reg |= VIDCON1_VCLK_RUN;
+                writel(reg, sfb->regs + VIDCON1);
+        }
+
         /* zero all windows before we do anything */
         for (win_no = 0; win_no < sfb->variant.nr_windows; win_no++)
                 s3c_fb_clear_win(sfb, win_no);
@@ -1845,6 +1865,7 @@ static struct s3c_fb_driverdata s3c_fb_data_s5pv210 = {
                 .has_shadowcon  = 1,
                 .has_blendcon   = 1,
                 .has_clksel     = 1,
+                .has_fixvclk    = 1,
         },
         .win[0] = &s3c_fb_data_s5p_wins[0],
         .win[1] = &s3c_fb_data_s5p_wins[1],
@@ -1876,6 +1897,7 @@ static struct s3c_fb_driverdata s3c_fb_data_exynos4 = {
 
                 .has_shadowcon  = 1,
                 .has_blendcon   = 1,
+                .has_fixvclk    = 1,
         },
         .win[0] = &s3c_fb_data_s5p_wins[0],
         .win[1] = &s3c_fb_data_s5p_wins[1],
@@ -1941,6 +1963,7 @@ static struct s3c_fb_driverdata s3c_fb_data_s5p64x0 = {
                 },
 
                 .has_blendcon   = 1,
+                .has_fixvclk    = 1,
         },
         .win[0] = &s3c_fb_data_s5p_wins[0],
         .win[1] = &s3c_fb_data_s5p_wins[1],