diff mbox

[1/3] drm: bridge: synopsys/dw-hdmi: Enable cec clock

Message ID 20171013225337.5196-2-phh@phh.me (mailing list archive)
State New, archived
Headers show

Commit Message

Pierre-Hugues Husson Oct. 13, 2017, 10:53 p.m. UTC
The documentation already mentions "cec" optional clock, but
currently the driver doesn't enable it.

Signed-off-by: Pierre-Hugues Husson <phh@phh.me>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

Comments

Fabio Estevam Oct. 14, 2017, 12:18 a.m. UTC | #1
Hi Pierre-Hugues,

On Fri, Oct 13, 2017 at 7:53 PM, Pierre-Hugues Husson <phh@phh.me> wrote:
> The documentation already mentions "cec" optional clock, but
> currently the driver doesn't enable it.

The cec clock is enabled at dw_hdmi_cec_enable().
Hans Verkuil Oct. 14, 2017, 8:16 a.m. UTC | #2
On 10/14/2017 12:53 AM, Pierre-Hugues Husson wrote:
> The documentation already mentions "cec" optional clock, but
> currently the driver doesn't enable it.
> 
> Signed-off-by: Pierre-Hugues Husson <phh@phh.me>

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>

Thanks!

	Hans

> ---
>  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> index bf14214fa464..5007cdf43131 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 +2383,18 @@ __dw_hdmi_probe(struct platform_device *pdev,
>  		goto err_isfr;
>  	}
>  
> +	hdmi->cec_clk = devm_clk_get(hdmi->dev, "cec");
> +	if (IS_ERR(hdmi->cec_clk)) {
> +		hdmi->cec_clk = NULL;
> +	} else {
> +		ret = clk_prepare_enable(hdmi->cec_clk);
> +		if (ret) {
> +			dev_err(hdmi->dev, "Cannot enable HDMI cec clock: %d\n",
> +					ret);
> +			goto err_res;
> +		}
> +	}
> +
>  	/* Product and revision IDs */
>  	hdmi->version = (hdmi_readb(hdmi, HDMI_DESIGN_ID) << 8)
>  		      | (hdmi_readb(hdmi, HDMI_REVISION_ID) << 0);
> @@ -2518,6 +2531,8 @@ __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 +2556,8 @@ 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);
>
Pierre-Hugues Husson Oct. 14, 2017, 1:21 p.m. UTC | #3
Hi Fabio,

2017-10-14 2:18 GMT+02:00 Fabio Estevam <festevam@gmail.com>:
> Hi Pierre-Hugues,
>
> On Fri, Oct 13, 2017 at 7:53 PM, Pierre-Hugues Husson <phh@phh.me> wrote:
>> The documentation already mentions "cec" optional clock, but
>> currently the driver doesn't enable it.
>
> The cec clock is enabled at dw_hdmi_cec_enable().
As far as I understand, dw_hdmi_cec_enable only gates
the CEC clock inside the Synopsis IP,
but the SOC still has to provide a specific CEC clock to it.
To enable such an external CEC clock, the binding documentation [1]
mentions a "cec" optional clock, and I'm not seeing any code in dw-hdmi
to enable it.

Regards,

[1] On next-20170929
Documentation/devicetree/bindings/display/bridge/dw_hdmi.txt line 28
Fabio Estevam Oct. 14, 2017, 1:41 p.m. UTC | #4
Hi Pierre,

On Sat, Oct 14, 2017 at 10:21 AM, Pierre-Hugues Husson <phh@phh.me> wrote:

> As far as I understand, dw_hdmi_cec_enable only gates
> the CEC clock inside the Synopsis IP,
> but the SOC still has to provide a specific CEC clock to it.
> To enable such an external CEC clock, the binding documentation [1]
> mentions a "cec" optional clock, and I'm not seeing any code in dw-hdmi
> to enable it.

Ok, understood.

In the case of i.MX6 we control the CEC clock via
HDMI_MC_CLKDIS_CECCLK_DISABLE bit inside the Synopsis IP.

Looks like Rockchip needs the external CEC clock then.

Regards,

Fabio Estevam
Hans Verkuil Oct. 20, 2017, 7:25 a.m. UTC | #5
On 14/10/17 10:16, Hans Verkuil wrote:
> On 10/14/2017 12:53 AM, Pierre-Hugues Husson wrote:
>> The documentation already mentions "cec" optional clock, but
>> currently the driver doesn't enable it.
>>
>> Signed-off-by: Pierre-Hugues Husson <phh@phh.me>
> 
> Acked-by: Hans Verkuil <hans.verkuil@cisco.com>

Tested-by: Hans Verkuil <hans.verkuil@cisco.com>

> 
> Thanks!
> 
> 	Hans
> 
>> ---
>>  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 17 +++++++++++++++++
>>  1 file changed, 17 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> index bf14214fa464..5007cdf43131 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 +2383,18 @@ __dw_hdmi_probe(struct platform_device *pdev,
>>  		goto err_isfr;
>>  	}
>>  
>> +	hdmi->cec_clk = devm_clk_get(hdmi->dev, "cec");
>> +	if (IS_ERR(hdmi->cec_clk)) {
>> +		hdmi->cec_clk = NULL;
>> +	} else {
>> +		ret = clk_prepare_enable(hdmi->cec_clk);
>> +		if (ret) {
>> +			dev_err(hdmi->dev, "Cannot enable HDMI cec clock: %d\n",
>> +					ret);
>> +			goto err_res;
>> +		}
>> +	}
>> +
>>  	/* Product and revision IDs */
>>  	hdmi->version = (hdmi_readb(hdmi, HDMI_DESIGN_ID) << 8)
>>  		      | (hdmi_readb(hdmi, HDMI_REVISION_ID) << 0);
>> @@ -2518,6 +2531,8 @@ __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 +2556,8 @@ 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);
>>
>
Russell King (Oracle) Oct. 20, 2017, 8:12 a.m. UTC | #6
On Sat, Oct 14, 2017 at 12:53:35AM +0200, Pierre-Hugues Husson wrote:
> @@ -2382,6 +2383,18 @@ __dw_hdmi_probe(struct platform_device *pdev,
>  		goto err_isfr;
>  	}
>  
> +	hdmi->cec_clk = devm_clk_get(hdmi->dev, "cec");
> +	if (IS_ERR(hdmi->cec_clk)) {
> +		hdmi->cec_clk = NULL;

What if devm_clk_get() returns EPROBE_DEFER?  Does that really mean the
clock does not exist?
Pierre-Hugues Husson Oct. 20, 2017, 7:21 p.m. UTC | #7
2017-10-20 10:12 GMT+02:00 Russell King - ARM Linux <linux@armlinux.org.uk>:
> On Sat, Oct 14, 2017 at 12:53:35AM +0200, Pierre-Hugues Husson wrote:
>> @@ -2382,6 +2383,18 @@ __dw_hdmi_probe(struct platform_device *pdev,
>>               goto err_isfr;
>>       }
>>
>> +     hdmi->cec_clk = devm_clk_get(hdmi->dev, "cec");
>> +     if (IS_ERR(hdmi->cec_clk)) {
>> +             hdmi->cec_clk = NULL;
>
> What if devm_clk_get() returns EPROBE_DEFER?  Does that really mean the
> clock does not exist?
Should be fixed in v2.
Thanks
diff mbox

Patch

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index bf14214fa464..5007cdf43131 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 +2383,18 @@  __dw_hdmi_probe(struct platform_device *pdev,
 		goto err_isfr;
 	}
 
+	hdmi->cec_clk = devm_clk_get(hdmi->dev, "cec");
+	if (IS_ERR(hdmi->cec_clk)) {
+		hdmi->cec_clk = NULL;
+	} else {
+		ret = clk_prepare_enable(hdmi->cec_clk);
+		if (ret) {
+			dev_err(hdmi->dev, "Cannot enable HDMI cec clock: %d\n",
+					ret);
+			goto err_res;
+		}
+	}
+
 	/* Product and revision IDs */
 	hdmi->version = (hdmi_readb(hdmi, HDMI_DESIGN_ID) << 8)
 		      | (hdmi_readb(hdmi, HDMI_REVISION_ID) << 0);
@@ -2518,6 +2531,8 @@  __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 +2556,8 @@  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);