diff mbox

[v2,2/2] drm: dw-hdmi: gate audio clock from the I2S enablement callbacks

Message ID 20170414083113.4255-3-romain.perier@collabora.com (mailing list archive)
State New, archived
Headers show

Commit Message

Romain Perier April 14, 2017, 8:31 a.m. UTC
Currently, the audio sampler clock is enabled from dw_hdmi_setup() at
step E. and is kept enabled for later use. This clock should be enabled
and disabled along with the actual audio stream and not always on (that
is bad for PM). Futhermore, as described by the datasheet, the I2S
variant need to gate/ungate the clock when the stream is
enabled/disabled.

This commit adds a parameter to hdmi_audio_enable_clk() that controls
when the audio sample clock must be enabled or disabled. Then, it adds
the call to this function from dw_hdmi_i2s_audio_enable() and
dw_hdmi_i2s_audio_disable().

Signed-off-by: Romain Perier <romain.perier@collabora.com>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

Comments

Archit Taneja April 19, 2017, 4:51 a.m. UTC | #1
On 04/14/2017 02:01 PM, Romain Perier wrote:
> Currently, the audio sampler clock is enabled from dw_hdmi_setup() at
> step E. and is kept enabled for later use. This clock should be enabled
> and disabled along with the actual audio stream and not always on (that
> is bad for PM). Futhermore, as described by the datasheet, the I2S

s/Futhermore/Furthermore

> variant need to gate/ungate the clock when the stream is

s/need/needs

> enabled/disabled.
>
> This commit adds a parameter to hdmi_audio_enable_clk() that controls
> when the audio sample clock must be enabled or disabled. Then, it adds
> the call to this function from dw_hdmi_i2s_audio_enable() and
> dw_hdmi_i2s_audio_disable().
>
> Signed-off-by: Romain Perier <romain.perier@collabora.com>
> ---
>  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 20 ++++++++++++++------
>  1 file changed, 14 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> index 5b328c0..a6da634 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> @@ -544,6 +544,12 @@ void dw_hdmi_set_sample_rate(struct dw_hdmi *hdmi, unsigned int rate)
>  }
>  EXPORT_SYMBOL_GPL(dw_hdmi_set_sample_rate);
>
> +static void hdmi_enable_audio_clk(struct dw_hdmi *hdmi, bool enable)
> +{
> +	hdmi_modb(hdmi, enable ? 0 : HDMI_MC_CLKDIS_AUDCLK_DISABLE,
> +		  HDMI_MC_CLKDIS_AUDCLK_DISABLE, HDMI_MC_CLKDIS);
> +}
> +
>  void dw_hdmi_ahb_audio_enable(struct dw_hdmi *hdmi)
>  {
>  	hdmi_set_cts_n(hdmi, hdmi->audio_cts, hdmi->audio_n);
> @@ -557,6 +563,12 @@ void dw_hdmi_ahb_audio_disable(struct dw_hdmi *hdmi)
>  void dw_hdmi_i2s_audio_enable(struct dw_hdmi *hdmi)
>  {
>  	hdmi_set_cts_n(hdmi, hdmi->audio_cts, hdmi->audio_n);
> +	hdmi_enable_audio_clk(hdmi, true);
> +}
> +
> +void dw_hdmi_i2s_audio_disable(struct dw_hdmi *hdmi)
> +{
> +	hdmi_enable_audio_clk(hdmi, false);
>  }

This should be static too.

If you're okay with the suggestions, I can fix these myself and push. Let
me know if that's okay.

Thanks,
Archit

>
>  void dw_hdmi_audio_enable(struct dw_hdmi *hdmi)
> @@ -1592,11 +1604,6 @@ static void dw_hdmi_enable_video_path(struct dw_hdmi *hdmi)
>  			    HDMI_MC_FLOWCTRL);
>  }
>
> -static void hdmi_enable_audio_clk(struct dw_hdmi *hdmi)
> -{
> -	hdmi_modb(hdmi, 0, HDMI_MC_CLKDIS_AUDCLK_DISABLE, HDMI_MC_CLKDIS);
> -}
> -
>  /* Workaround to clear the overflow condition */
>  static void dw_hdmi_clear_overflow(struct dw_hdmi *hdmi)
>  {
> @@ -1710,7 +1717,7 @@ static int dw_hdmi_setup(struct dw_hdmi *hdmi, struct drm_display_mode *mode)
>
>  		/* HDMI Initialization Step E - Configure audio */
>  		hdmi_clk_regenerator_update_pixel_clock(hdmi);
> -		hdmi_enable_audio_clk(hdmi);
> +		hdmi_enable_audio_clk(hdmi, true);
>  	}
>
>  	/* not for DVI mode */
> @@ -2438,6 +2445,7 @@ __dw_hdmi_probe(struct platform_device *pdev,
>  		audio.write	= hdmi_writeb;
>  		audio.read	= hdmi_readb;
>  		hdmi->enable_audio = dw_hdmi_i2s_audio_enable;
> +		hdmi->disable_audio = dw_hdmi_i2s_audio_disable;
>
>  		pdevinfo.name = "dw-hdmi-i2s-audio";
>  		pdevinfo.data = &audio;
>
Archit Taneja April 20, 2017, 9:39 a.m. UTC | #2
On 04/19/2017 10:21 AM, Archit Taneja wrote:
>
>
> On 04/14/2017 02:01 PM, Romain Perier wrote:
>> Currently, the audio sampler clock is enabled from dw_hdmi_setup() at
>> step E. and is kept enabled for later use. This clock should be enabled
>> and disabled along with the actual audio stream and not always on (that
>> is bad for PM). Futhermore, as described by the datasheet, the I2S
>
> s/Futhermore/Furthermore
>
>> variant need to gate/ungate the clock when the stream is
>
> s/need/needs
>
>> enabled/disabled.
>>
>> This commit adds a parameter to hdmi_audio_enable_clk() that controls
>> when the audio sample clock must be enabled or disabled. Then, it adds
>> the call to this function from dw_hdmi_i2s_audio_enable() and
>> dw_hdmi_i2s_audio_disable().
>>
>> Signed-off-by: Romain Perier <romain.perier@collabora.com>
>> ---
>>  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 20 ++++++++++++++------
>>  1 file changed, 14 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> index 5b328c0..a6da634 100644
>> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> @@ -544,6 +544,12 @@ void dw_hdmi_set_sample_rate(struct dw_hdmi *hdmi, unsigned int rate)
>>  }
>>  EXPORT_SYMBOL_GPL(dw_hdmi_set_sample_rate);
>>
>> +static void hdmi_enable_audio_clk(struct dw_hdmi *hdmi, bool enable)
>> +{
>> +    hdmi_modb(hdmi, enable ? 0 : HDMI_MC_CLKDIS_AUDCLK_DISABLE,
>> +          HDMI_MC_CLKDIS_AUDCLK_DISABLE, HDMI_MC_CLKDIS);
>> +}
>> +
>>  void dw_hdmi_ahb_audio_enable(struct dw_hdmi *hdmi)
>>  {
>>      hdmi_set_cts_n(hdmi, hdmi->audio_cts, hdmi->audio_n);
>> @@ -557,6 +563,12 @@ void dw_hdmi_ahb_audio_disable(struct dw_hdmi *hdmi)
>>  void dw_hdmi_i2s_audio_enable(struct dw_hdmi *hdmi)
>>  {
>>      hdmi_set_cts_n(hdmi, hdmi->audio_cts, hdmi->audio_n);
>> +    hdmi_enable_audio_clk(hdmi, true);
>> +}
>> +
>> +void dw_hdmi_i2s_audio_disable(struct dw_hdmi *hdmi)
>> +{
>> +    hdmi_enable_audio_clk(hdmi, false);
>>  }
>
> This should be static too.
>
> If you're okay with the suggestions, I can fix these myself and push. Let
> me know if that's okay.

Took the liberty of going ahead with the fixes. Queued both patches to
drm-misc-next.

Thanks,
Archit

>
> Thanks,
> Archit
>
>>
>>  void dw_hdmi_audio_enable(struct dw_hdmi *hdmi)
>> @@ -1592,11 +1604,6 @@ static void dw_hdmi_enable_video_path(struct dw_hdmi *hdmi)
>>                  HDMI_MC_FLOWCTRL);
>>  }
>>
>> -static void hdmi_enable_audio_clk(struct dw_hdmi *hdmi)
>> -{
>> -    hdmi_modb(hdmi, 0, HDMI_MC_CLKDIS_AUDCLK_DISABLE, HDMI_MC_CLKDIS);
>> -}
>> -
>>  /* Workaround to clear the overflow condition */
>>  static void dw_hdmi_clear_overflow(struct dw_hdmi *hdmi)
>>  {
>> @@ -1710,7 +1717,7 @@ static int dw_hdmi_setup(struct dw_hdmi *hdmi, struct drm_display_mode *mode)
>>
>>          /* HDMI Initialization Step E - Configure audio */
>>          hdmi_clk_regenerator_update_pixel_clock(hdmi);
>> -        hdmi_enable_audio_clk(hdmi);
>> +        hdmi_enable_audio_clk(hdmi, true);
>>      }
>>
>>      /* not for DVI mode */
>> @@ -2438,6 +2445,7 @@ __dw_hdmi_probe(struct platform_device *pdev,
>>          audio.write    = hdmi_writeb;
>>          audio.read    = hdmi_readb;
>>          hdmi->enable_audio = dw_hdmi_i2s_audio_enable;
>> +        hdmi->disable_audio = dw_hdmi_i2s_audio_disable;
>>
>>          pdevinfo.name = "dw-hdmi-i2s-audio";
>>          pdevinfo.data = &audio;
>>
>
Romain Perier April 24, 2017, 6:44 a.m. UTC | #3
Hello,


Le 19/04/2017 à 06:51, Archit Taneja a écrit :
>
>
> On 04/14/2017 02:01 PM, Romain Perier wrote:
>> Currently, the audio sampler clock is enabled from dw_hdmi_setup() at
>> step E. and is kept enabled for later use. This clock should be enabled
>> and disabled along with the actual audio stream and not always on (that
>> is bad for PM). Futhermore, as described by the datasheet, the I2S
>
> s/Futhermore/Furthermore
>
>> variant need to gate/ungate the clock when the stream is
>
> s/need/needs
>
>> enabled/disabled.
>>
>> This commit adds a parameter to hdmi_audio_enable_clk() that controls
>> when the audio sample clock must be enabled or disabled. Then, it adds
>> the call to this function from dw_hdmi_i2s_audio_enable() and
>> dw_hdmi_i2s_audio_disable().
>>
>> Signed-off-by: Romain Perier <romain.perier@collabora.com>
>> ---
>>  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 20 ++++++++++++++------
>>  1 file changed, 14 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> index 5b328c0..a6da634 100644
>> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> @@ -544,6 +544,12 @@ void dw_hdmi_set_sample_rate(struct dw_hdmi
>> *hdmi, unsigned int rate)
>>  }
>>  EXPORT_SYMBOL_GPL(dw_hdmi_set_sample_rate);
>>
>> +static void hdmi_enable_audio_clk(struct dw_hdmi *hdmi, bool enable)
>> +{
>> +    hdmi_modb(hdmi, enable ? 0 : HDMI_MC_CLKDIS_AUDCLK_DISABLE,
>> +          HDMI_MC_CLKDIS_AUDCLK_DISABLE, HDMI_MC_CLKDIS);
>> +}
>> +
>>  void dw_hdmi_ahb_audio_enable(struct dw_hdmi *hdmi)
>>  {
>>      hdmi_set_cts_n(hdmi, hdmi->audio_cts, hdmi->audio_n);
>> @@ -557,6 +563,12 @@ void dw_hdmi_ahb_audio_disable(struct dw_hdmi
>> *hdmi)
>>  void dw_hdmi_i2s_audio_enable(struct dw_hdmi *hdmi)
>>  {
>>      hdmi_set_cts_n(hdmi, hdmi->audio_cts, hdmi->audio_n);
>> +    hdmi_enable_audio_clk(hdmi, true);
>> +}
>> +
>> +void dw_hdmi_i2s_audio_disable(struct dw_hdmi *hdmi)
>> +{
>> +    hdmi_enable_audio_clk(hdmi, false);
>>  }
>
> This should be static too.
>
> If you're okay with the suggestions, I can fix these myself and push. Let
> me know if that's okay.
>
> Thanks,
> Archit
>

Yes, I completely agree.
Thanks,
Romain
Romain Perier April 24, 2017, 6:55 a.m. UTC | #4
Hello,

> Took the liberty of going ahead with the fixes. Queued both patches to
> drm-misc-next.
>
> Thanks,
> Archit

You were right. Sorry for the delay, I am back from vacations :)

Regards,
Romain
diff mbox

Patch

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 5b328c0..a6da634 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -544,6 +544,12 @@  void dw_hdmi_set_sample_rate(struct dw_hdmi *hdmi, unsigned int rate)
 }
 EXPORT_SYMBOL_GPL(dw_hdmi_set_sample_rate);
 
+static void hdmi_enable_audio_clk(struct dw_hdmi *hdmi, bool enable)
+{
+	hdmi_modb(hdmi, enable ? 0 : HDMI_MC_CLKDIS_AUDCLK_DISABLE,
+		  HDMI_MC_CLKDIS_AUDCLK_DISABLE, HDMI_MC_CLKDIS);
+}
+
 void dw_hdmi_ahb_audio_enable(struct dw_hdmi *hdmi)
 {
 	hdmi_set_cts_n(hdmi, hdmi->audio_cts, hdmi->audio_n);
@@ -557,6 +563,12 @@  void dw_hdmi_ahb_audio_disable(struct dw_hdmi *hdmi)
 void dw_hdmi_i2s_audio_enable(struct dw_hdmi *hdmi)
 {
 	hdmi_set_cts_n(hdmi, hdmi->audio_cts, hdmi->audio_n);
+	hdmi_enable_audio_clk(hdmi, true);
+}
+
+void dw_hdmi_i2s_audio_disable(struct dw_hdmi *hdmi)
+{
+	hdmi_enable_audio_clk(hdmi, false);
 }
 
 void dw_hdmi_audio_enable(struct dw_hdmi *hdmi)
@@ -1592,11 +1604,6 @@  static void dw_hdmi_enable_video_path(struct dw_hdmi *hdmi)
 			    HDMI_MC_FLOWCTRL);
 }
 
-static void hdmi_enable_audio_clk(struct dw_hdmi *hdmi)
-{
-	hdmi_modb(hdmi, 0, HDMI_MC_CLKDIS_AUDCLK_DISABLE, HDMI_MC_CLKDIS);
-}
-
 /* Workaround to clear the overflow condition */
 static void dw_hdmi_clear_overflow(struct dw_hdmi *hdmi)
 {
@@ -1710,7 +1717,7 @@  static int dw_hdmi_setup(struct dw_hdmi *hdmi, struct drm_display_mode *mode)
 
 		/* HDMI Initialization Step E - Configure audio */
 		hdmi_clk_regenerator_update_pixel_clock(hdmi);
-		hdmi_enable_audio_clk(hdmi);
+		hdmi_enable_audio_clk(hdmi, true);
 	}
 
 	/* not for DVI mode */
@@ -2438,6 +2445,7 @@  __dw_hdmi_probe(struct platform_device *pdev,
 		audio.write	= hdmi_writeb;
 		audio.read	= hdmi_readb;
 		hdmi->enable_audio = dw_hdmi_i2s_audio_enable;
+		hdmi->disable_audio = dw_hdmi_i2s_audio_disable;
 
 		pdevinfo.name = "dw-hdmi-i2s-audio";
 		pdevinfo.data = &audio;