Re: [PATCHv2 4/4] drm: exynos: hdmi: add support for pixel clock limitation

Hi Tomasz,

On 15 April 2014 14:57, Tomasz Stanislawski t.stanislaws@samsung.com wrote:

Adds support for limitation of maximal pixel clock of HDMI signal. This feature is needed on boards that contains lines or bridges with frequency limitations.

Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com

.../devicetree/bindings/video/exynos_hdmi.txt | 4 ++++ drivers/gpu/drm/exynos/exynos_hdmi.c | 12 ++++++++++++ include/media/s5p_hdmi.h | 1 + 3 files changed, 17 insertions(+)

diff --git a/Documentation/devicetree/bindings/video/exynos_hdmi.txt b/Documentation/devicetree/bindings/video/exynos_hdmi.txt index f9187a2..8718f8d 100644 --- a/Documentation/devicetree/bindings/video/exynos_hdmi.txt +++ b/Documentation/devicetree/bindings/video/exynos_hdmi.txt @@ -28,6 +28,10 @@ Required properties:

• ddc: phandle to the hdmi ddc node
• phy: phandle to the hdmi phy node

+Optional properties: +- max-pixel-clock: used to limit the maximal pixel clock if a board has lines,

•   connectors or bridges not capable of carring higher frequencies
  

Example:

    hdmi {

diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c index 2a18f4e..404f1b7 100644 --- a/drivers/gpu/drm/exynos/exynos_hdmi.c +++ b/drivers/gpu/drm/exynos/exynos_hdmi.c @@ -195,6 +195,7 @@ struct hdmi_context { struct hdmi_resources res;

    int                             hpd_gpio;

•   u32                             max_pixel_clock;
  
    enum hdmi_type                  type;
  

}; @@ -887,6 +888,9 @@ static int hdmi_mode_valid(struct drm_connector *connector, if (ret) return MODE_BAD;

•   if (mode->clock * 1000 > hdata->max_pixel_clock)
  

•           return MODE_BAD;
  

•   ret = hdmi_find_phy_conf(hdata, mode->clock * 1000);
    if (ret < 0)
            return MODE_BAD;
  

@@ -2031,6 +2035,8 @@ static struct s5p_hdmi_platform_data *drm_hdmi_dt_parse_pdata return NULL; }

•   of_property_read_u32(np, "max-pixel-clock", &pd->max_pixel_clock);
  

•   return pd;
  

}

@@ -2067,6 +2073,11 @@ static int hdmi_probe(struct platform_device *pdev) if (!pdata) return -EINVAL;

•   if (!pdata->max_pixel_clock) {
  

•           DRM_INFO("max-pixel-clock is zero, using INF\n");
  

•           pdata->max_pixel_clock = U32_MAX;
  

•   }
  

•   hdata = devm_kzalloc(dev, sizeof(struct hdmi_context), GFP_KERNEL);
    if (!hdata)
            return -ENOMEM;
  

@@ -2083,6 +2094,7 @@ static int hdmi_probe(struct platform_device *pdev) hdata->type = drv_data->type;

    hdata->hpd_gpio = pdata->hpd_gpio;

•   hdata->max_pixel_clock = pdata->max_pixel_clock;
    hdata->dev = dev;
  
    ret = hdmi_resources_init(hdata);
  

diff --git a/include/media/s5p_hdmi.h b/include/media/s5p_hdmi.h index 181642b..7272d65 100644 --- a/include/media/s5p_hdmi.h +++ b/include/media/s5p_hdmi.h @@ -31,6 +31,7 @@ struct s5p_hdmi_platform_data { int mhl_bus; struct i2c_board_info *mhl_info; int hpd_gpio;

•   u32 max_pixel_clock;
  

};

We have already removed Non DT support from the drm hdmi driver. IMO we should not be extending the pdata struct.

Regards, Rahul Sharma

#endif /* S5P_HDMI_H */

1.7.9.5

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