[PATCH v2] drm: bridge: synopsys/dw-hdmi: Enable cec clock

[Pierre-Hugues Husson]

The documentation already mentions "cec" optional clock, but
currently the driver doesn't enable it.

Changes:
v2:
- Separate ENOENT errors from others
- Propagate other errors (especially -EPROBE_DEFER)

Signed-off-by: Pierre-Hugues Husson <p...@phh.me>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c 
b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index bf14214fa464..b31fc95d5fef 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -138,6 +138,7 @@ struct dw_hdmi {
        struct device *dev;
        struct clk *isfr_clk;
        struct clk *iahb_clk;
+       struct clk *cec_clk;
        struct dw_hdmi_i2c *i2c;
 
        struct hdmi_data_info hdmi_data;
@@ -2382,6 +2383,27 @@ __dw_hdmi_probe(struct platform_device *pdev,
                goto err_isfr;
        }
 
+       hdmi->cec_clk = devm_clk_get(hdmi->dev, "cec");
+       if (PTR_ERR(hdmi->cec_clk) == -ENOENT) {
+               hdmi->cec_clk = NULL;
+       } else if (IS_ERR(hdmi->cec_clk)) {
+               ret = PTR_ERR(hdmi->cec_clk);
+               if (ret != -EPROBE_DEFER) {
+                       dev_err(hdmi->dev, "Cannot get HDMI cec clock: %d\n",
+                                       ret);
+               }
+
+               hdmi->cec_clk = NULL;
+               goto err_iahb;
+       } else {
+               ret = clk_prepare_enable(hdmi->cec_clk);
+               if (ret) {
+                       dev_err(hdmi->dev, "Cannot enable HDMI cec clock: %d\n",
+                                       ret);
+                       goto err_iahb;
+               }
+       }
+
        /* Product and revision IDs */
        hdmi->version = (hdmi_readb(hdmi, HDMI_DESIGN_ID) << 8)
                      | (hdmi_readb(hdmi, HDMI_REVISION_ID) << 0);
@@ -2518,6 +2540,8 @@ __dw_hdmi_probe(struct platform_device *pdev,
                cec_notifier_put(hdmi->cec_notifier);
 
        clk_disable_unprepare(hdmi->iahb_clk);
+       if (hdmi->cec_clk)
+               clk_disable_unprepare(hdmi->cec_clk);
 err_isfr:
        clk_disable_unprepare(hdmi->isfr_clk);
 err_res:
@@ -2541,6 +2565,8 @@ static void __dw_hdmi_remove(struct dw_hdmi *hdmi)
 
        clk_disable_unprepare(hdmi->iahb_clk);
        clk_disable_unprepare(hdmi->isfr_clk);
+       if (hdmi->cec_clk)
+               clk_disable_unprepare(hdmi->cec_clk);
 
        if (hdmi->i2c)
                i2c_del_adapter(&hdmi->i2c->adap);
-- 
2.14.1