Re: [PATCH V3 1/7] drm/exynos: Support DP CLKCON register in FIMD driver

Hi Andrej,

On Fri, Jun 27, 2014 at 4:52 PM, Andrzej Hajda [off-list ref] wrote:

Hi Ajay,

+CC DT

On 06/27/2014 12:12 PM, Ajay Kumar wrote:

quoted

Add the missing setting for DP CLKCON register.

This register is present on Exynos5 based FIMD controllers,
and needs to be set if we are using DP.

Signed-off-by: Ajay Kumar <redacted>
---
 .../devicetree/bindings/video/samsung-fimd.txt     |    1 +
 drivers/gpu/drm/exynos/exynos_drm_fimd.c           |   23 ++++++++++++++++++++
 include/video/samsung_fimd.h                       |    4 ++++
 3 files changed, 28 insertions(+)

diff --git a/Documentation/devicetree/bindings/video/samsung-fimd.txt b/Documentation/devicetree/bindings/video/samsung-fimd.txt
index 2dad41b..12f3d7a 100644
--- a/Documentation/devicetree/bindings/video/samsung-fimd.txt
+++ b/Documentation/devicetree/bindings/video/samsung-fimd.txt

@@ -41,6 +41,7 @@ Optional Properties:
 - samsung,power-domain: a phandle to FIMD power domain node.
 - samsung,invert-vden: video enable signal is inverted
 - samsung,invert-vclk: video clock signal is inverted
+- samsung,output-type: Type of display output interface(DPI=0, DSI=1, DP=2)

There is no point in introducing this property. Exynos DRM have already
logic which creates pipeline: fimd --> DPI|DSI|DP, this logic can be
reused to determine display type. It can be done even without any
additional callbacks, just by checking if there is connector of
DRM_MODE_CONNECTOR_eDP type connected to fimd.

The mapping between crtc(struct exynos_drm_manager) and encoder(struct
exynos_drm_display)
in exynos drm happens by matching the exynos_drm_output_type variable in each
structure.
exynos_drm_output_type supports 3 types: LCD, HDMI and VIDI.
FIMD statically chooses EXYNOS_DISPLAY_TYPE_LCD as the output type,
and both DP and MIPI statically choose the same enum EXYNOS_DISPLAY_TYPE_LCD,
as output type.
So, we cannot use that logic to differentiate between DP/MIPI DSI.

Also, checking based on connector type doesn't hold good.
The connector type will be DRM_MODE_CONNECTOR_LVDS in case of
DP->LVDS or MIPI->LVDS panels!

Thanks and regards,
Ajay Kumar

Regards
Andrzej

quoted

 - display-timings: timing settings for FIMD, as described in document [1].
              Can be used in case timings cannot be provided otherwise
              or to override timings provided by the panel.

diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.c b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
index 33161ad..aa74e90 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fimd.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.c

@@ -72,6 +72,7 @@ struct fimd_driver_data {
      unsigned int has_shadowcon:1;
      unsigned int has_clksel:1;
      unsigned int has_limited_fmt:1;
+     unsigned int has_dp_clkcon:1;
 };

 static struct fimd_driver_data s3c64xx_fimd_driver_data = {

@@ -88,6 +89,13 @@ static struct fimd_driver_data exynos4_fimd_driver_data = {
 static struct fimd_driver_data exynos5_fimd_driver_data = {
      .timing_base = 0x20000,
      .has_shadowcon = 1,
+     .has_dp_clkcon = 1,
+};
+
+enum exynos_fimd_output_type {
+     EXYNOS_FIMD_OUTPUT_DPI,
+     EXYNOS_FIMD_OUTPUT_DSI,
+     EXYNOS_FIMD_OUTPUT_DP,
 };

 struct fimd_win_data {

@@ -125,6 +133,8 @@ struct fimd_context {
      struct exynos_drm_panel_info panel;
      struct fimd_driver_data *driver_data;
      struct exynos_drm_display *display;
+
+     enum exynos_fimd_output_type exynos_fimd_output_type;
 };

 static const struct of_device_id fimd_driver_dt_match[] = {

@@ -331,6 +341,10 @@ static void fimd_commit(struct exynos_drm_manager *mgr)
      if (clkdiv > 1)
              val |= VIDCON0_CLKVAL_F(clkdiv - 1) | VIDCON0_CLKDIR;

+     if (ctx->driver_data->has_dp_clkcon &&
+             ctx->exynos_fimd_output_type == EXYNOS_FIMD_OUTPUT_DP)
+             writel(DP_CLK_ENABLE, ctx->regs + DP_CLKCON);
+
      writel(val, ctx->regs + VIDCON0);
 }

@@ -924,6 +938,7 @@ static int fimd_probe(struct platform_device *pdev)
      struct device *dev = &pdev->dev;
      struct fimd_context *ctx;
      struct resource *res;
+     u32 fimd_output_type;
      int ret = -EINVAL;

      ret = exynos_drm_component_add(&pdev->dev, EXYNOS_DEVICE_TYPE_CRTC,

@@ -949,6 +964,14 @@ static int fimd_probe(struct platform_device *pdev)
              ctx->vidcon1 |= VIDCON1_INV_VDEN;
      if (of_property_read_bool(dev->of_node, "samsung,invert-vclk"))
              ctx->vidcon1 |= VIDCON1_INV_VCLK;
+     if (!of_property_read_u32(dev->of_node, "samsung,output-type",
+                             &fimd_output_type)) {
+             if ((fimd_output_type < EXYNOS_FIMD_OUTPUT_DPI) ||
+                 (fimd_output_type > EXYNOS_FIMD_OUTPUT_DP))
+                     dev_err(dev, "invalid output type for FIMD\n");
+             else
+                     ctx->exynos_fimd_output_type = fimd_output_type;
+     }

      ctx->bus_clk = devm_clk_get(dev, "fimd");
      if (IS_ERR(ctx->bus_clk)) {

diff --git a/include/video/samsung_fimd.h b/include/video/samsung_fimd.h
index b039320..d8f4b0b 100644
--- a/include/video/samsung_fimd.h
+++ b/include/video/samsung_fimd.h

@@ -435,6 +435,10 @@
 #define BLENDCON_NEW_8BIT_ALPHA_VALUE                (1 << 0)
 #define BLENDCON_NEW_4BIT_ALPHA_VALUE                (0 << 0)

+/* Video clock enable for DP */
+#define DP_CLKCON                            0x27C
+#define DP_CLK_ENABLE                                0x2
+
 /* Notes on per-window bpp settings
  *
  * Value     Win0     Win1     Win2     Win3     Win 4