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

2017-10-20 Thread Pierre-Hugues Husson 
2017-10-20 10:12 GMT+02:00 Russell King - ARM Linux :
> 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

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

2017-10-20 Thread Russell King - ARM Linux 
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?

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

2017-10-20 Thread Hans Verkuil 
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 
> 
> Acked-by: Hans Verkuil 

Tested-by: Hans Verkuil 

> 
> 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(>i2c->adap);
>>
>

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

2017-10-14 Thread Fabio Estevam 
Hi Pierre,

On Sat, Oct 14, 2017 at 10:21 AM, Pierre-Hugues Husson  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

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

2017-10-14 Thread Pierre-Hugues Husson 
Hi Fabio,

2017-10-14 2:18 GMT+02:00 Fabio Estevam :
> Hi Pierre-Hugues,
>
> On Fri, Oct 13, 2017 at 7:53 PM, Pierre-Hugues Husson  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

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

2017-10-14 Thread Hans Verkuil 
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 

Acked-by: Hans Verkuil 

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(>i2c->adap);
>

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

2017-10-13 Thread Fabio Estevam 
Hi Pierre-Hugues,

On Fri, Oct 13, 2017 at 7:53 PM, Pierre-Hugues Husson  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().