Re: [PATCH v2 10/10] drm/hisilicon: Add support for external bridge

On 1 December 2015 at 17:04, Archit Taneja architt@codeaurora.org wrote:

On 11/28/2015 04:09 PM, Xinliang Liu wrote:

...

Add support for external HDMI bridge.

Signed-off-by: Xinliang Liu xinliang.liu@linaro.org Signed-off-by: Xinwei Kong kong.kongxinwei@hisilicon.com Signed-off-by: Andy Green andy.green@linaro.org

---

drivers/gpu/drm/hisilicon/hisi_drm_dsi.c | 51 ++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+)

diff --git a/drivers/gpu/drm/hisilicon/hisi_drm_dsi.c b/drivers/gpu/drm/hisilicon/hisi_drm_dsi.c index 066e08d..9e056db 100644 --- a/drivers/gpu/drm/hisilicon/hisi_drm_dsi.c +++ b/drivers/gpu/drm/hisilicon/hisi_drm_dsi.c @@ -78,6 +78,7 @@ struct dsi_hw_ctx {

struct hisi_dsi { struct drm_encoder encoder;

•   struct drm_bridge *bridge;
    struct mipi_dsi_host host;
    struct drm_display_mode cur_mode;
    struct dsi_hw_ctx *ctx;
  

@@ -671,6 +672,25 @@ static int dsi_host_init(struct device *dev, struct hisi_dsi *dsi) return 0; }

+static int dsi_bridge_init(struct drm_device *dev, struct hisi_dsi *dsi) +{

•   struct drm_encoder *encoder = &dsi->encoder;
  

•   struct drm_bridge *bridge = dsi->bridge;
  

•   int ret;
  

•   /* associate the bridge to dsi encoder */
  

•   encoder->bridge = bridge;
  

•   bridge->encoder = encoder;
  

•   ret = drm_bridge_attach(dev, bridge);
  

•   if (ret) {
  

•           DRM_ERROR("failed to attach exteranl bridge\n");
  

s/exteranl/external

will be fixed in v3.

...

•           return ret;
  

•   }
  

•   return 0;
  

+}

• static int dsi_bind(struct device *dev, struct device *master, void

*data) { struct dsi_data *ddata = dev_get_drvdata(dev); @@ -686,6 +706,10 @@ static int dsi_bind(struct device *dev, struct device *master, void *data) if (ret) return ret;

•   ret = dsi_bridge_init(drm_dev, dsi);
  

•   if (ret)
  

•           return ret;
  

•   return 0;
  

  }

@@ -702,8 +726,35 @@ static const struct component_ops dsi_ops = { static int dsi_parse_dt(struct platform_device *pdev, struct hisi_dsi *dsi) { struct dsi_hw_ctx *ctx = dsi->ctx;

•   struct device_node *np = pdev->dev.of_node;
  

•   struct device_node *endpoint, *bridge_node;
  

•   struct drm_bridge *bridge;
    struct resource *res;
  
  

•   /*
  

•    * Get the endpoint node. In our case, dsi has one output port
  

•    * to which the external HDMI bridge is connected.
  

•    */
  

•   endpoint = of_graph_get_next_endpoint(np, NULL);
  

•   if (!endpoint) {
  

•           DRM_ERROR("no valid endpoint node\n");
  

•           return -ENODEV;
  

•   }
  

•   of_node_put(endpoint);
  

•   bridge_node = of_graph_get_remote_port_parent(endpoint);
  

•   if (!bridge_node) {
  

•           DRM_ERROR("no valid bridge node\n");
  

•           return -ENODEV;
  

•   }
  

•   of_node_put(bridge_node);
  

•   bridge = of_drm_find_bridge(bridge_node);
  

•   if (!bridge) {
  

•           DRM_INFO("wait for external HDMI bridge driver.\n");
  

•           return -EPROBE_DEFER;
  

•   }
  

•   dsi->bridge = bridge;
  

This could be left for later, but it would be better if the dsi driver registers even if the bridge driver module isn't inserted yet, or happens much later in boot.

We could achieve this by trying to attach the bridge (done in dsi_bridge_init) in the dsi_host_attach callback instead of having it in dsi_bind.

Do you mean that it is the right time or place to attach the bridge in dsi_host_attach callback. Why? Because at this time bridge driver must be register?

Thanks, -xinliang

Thanks, Archit

...

    ctx->dsi_cfg_clk = devm_clk_get(&pdev->dev, "pclk_dsi");
    if (IS_ERR(ctx->dsi_cfg_clk)) {

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