diff mbox series

thermal: rcar_gen3_thermal: Add Standby-Mode function support

Message ID 1541142370-15225-1-git-send-email-na-hoan@jinso.co.jp (mailing list archive)
State Superseded
Delegated to: Geert Uytterhoeven
Headers show
Series thermal: rcar_gen3_thermal: Add Standby-Mode function support | expand

Commit Message

グェン・アン・ホァン Nov. 2, 2018, 7:06 a.m. UTC 
From: Hoan Nguyen An <na-hoan@jinso.co.jp>

According to the hardware manual, Gen3 supports Standby-mode.
Add this function, and we should use this function while
suspend to reduce the energy consumption.

Signed-off-by: Hoan Nguyen An <na-hoan@jinso.co.jp>
---
 drivers/thermal/rcar_gen3_thermal.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

Comments

Niklas Söderlund Nov. 2, 2018, 9:50 a.m. UTC | #1 
Hi Hoan,

Thanks for your work.

On 2018-11-02 16:06:10 +0900, Nguyen An Hoan wrote:
> From: Hoan Nguyen An <na-hoan@jinso.co.jp>
> 
> According to the hardware manual, Gen3 supports Standby-mode.
> Add this function, and we should use this function while
> suspend to reduce the energy consumption.

Out of curiosity is the power saved measurable?

> 
> Signed-off-by: Hoan Nguyen An <na-hoan@jinso.co.jp>
> ---
>  drivers/thermal/rcar_gen3_thermal.c | 23 ++++++++++++++++++++++-
>  1 file changed, 22 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/thermal/rcar_gen3_thermal.c b/drivers/thermal/rcar_gen3_thermal.c
> index 7aed533..85fc4b2 100644
> --- a/drivers/thermal/rcar_gen3_thermal.c
> +++ b/drivers/thermal/rcar_gen3_thermal.c
> @@ -447,11 +447,32 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
>  	return ret;
>  }
>  
> +static int rcar_gen3_thermal_standby(struct rcar_gen3_thermal_priv* priv)

I don't want to bikeshed about the name but the datasheet confuses me as 
it documents the standby and reset procedures to be exactly the same, or 
am I missing something? If they are indeed one and the same I would 
prefers this function to be called rcar_gen3_thermal_reset() and in 
rcar_gen3_thermal_suspend() add a comment "Reset to enter standby mode" 
or something similar. But it's up to you.

> +{
> +	unsigned int i;
> +	u32 reg_val;
> +
> +	for (i = 0; i < TSC_MAX_NUM; i++) {
> +		struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
> +
> +		rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, 0);
> +		rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
> +
> +		reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
> +		rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val & ~THCTR_THSST);

Too many new lines.

> +
> +
> +		usleep_range(1000, 2000);

Can't the sleep be moved outside the loop? We can reset all TSC and then 
wait the required 1 ms only once while they all are reset or are they 
somehow dependent on being reset in sequence?

> +	}
> +
> +	return 0;
> +}
> +
>  static int __maybe_unused rcar_gen3_thermal_suspend(struct device *dev)
>  {
>  	struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
>  
> -	rcar_thermal_irq_set(priv, false);
> +	rcar_gen3_thermal_standby(priv);
>  
>  	return 0;
>  }
> -- 
> 2.7.4
>
グェン・アン・ホァン Nov. 5, 2018, 1:02 a.m. UTC | #2 
Dear Niklas-san

Thank you for your comments!

On 2018/11/02 18:50, Niklas Söderlund wrote:
> Hi Hoan,
>
> Thanks for your work.
>
> On 2018-11-02 16:06:10 +0900, Nguyen An Hoan wrote:
>> From: Hoan Nguyen An <na-hoan@jinso.co.jp>
>>
>> According to the hardware manual, Gen3 supports Standby-mode.
>> Add this function, and we should use this function while
>> suspend to reduce the energy consumption.
> Out of curiosity is the power saved measurable?

I apologize for not investigating yet this issue. It is considered
  to reduce energy consumption that Equal to the power of the
  "A/D converter for the thermal sensor".

>> Signed-off-by: Hoan Nguyen An <na-hoan@jinso.co.jp>
>> ---
>>   drivers/thermal/rcar_gen3_thermal.c | 23 ++++++++++++++++++++++-
>>   1 file changed, 22 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/thermal/rcar_gen3_thermal.c b/drivers/thermal/rcar_gen3_thermal.c
>> index 7aed533..85fc4b2 100644
>> --- a/drivers/thermal/rcar_gen3_thermal.c
>> +++ b/drivers/thermal/rcar_gen3_thermal.c
>> @@ -447,11 +447,32 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
>>   	return ret;
>>   }
>>   
>> +static int rcar_gen3_thermal_standby(struct rcar_gen3_thermal_priv* priv)
> I don't want to bikeshed about the name but the datasheet confuses me as
> it documents the standby and reset procedures to be exactly the same, or
> am I missing something? If they are indeed one and the same I would
> prefers this function to be called rcar_gen3_thermal_reset() and in
> rcar_gen3_thermal_suspend() add a comment "Reset to enter standby mode"
> or something similar. But it's up to you.
I also find it strange that the procedures of Stand-by and Reset
are exactly the same. Since we should not doubt the accuracy of
the document. I will update v2 according to your comments.
>> +{
>> +	unsigned int i;
>> +	u32 reg_val;
>> +
>> +	for (i = 0; i < TSC_MAX_NUM; i++) {
>> +		struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
>> +
>> +		rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, 0);
>> +		rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
>> +
>> +		reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
>> +		rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val & ~THCTR_THSST);
> Too many new lines.

Thank, in addition this point, perhaps using 'priv->num_tscs' instead of

TSC_MAX_NUM would be more accurate!

>> +
>> +
>> +		usleep_range(1000, 2000);
> Can't the sleep be moved outside the loop? We can reset all TSC and then
> wait the required 1 ms only once while they all are reset or are they
> somehow dependent on being reset in sequence?

Thank you, that's right, exactly 1ms only once,
I will put usleep () outside at v2 of this patch.

Thank you very much for the review!

Hoan.

>> +	}
>> +
>> +	return 0;
>> +}
>> +
>>   static int __maybe_unused rcar_gen3_thermal_suspend(struct device *dev)
>>   {
>>   	struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
>>   
>> -	rcar_thermal_irq_set(priv, false);
>> +	rcar_gen3_thermal_standby(priv);
>>   
>>   	return 0;
>>   }
>> -- 
>> 2.7.4
>>
diff mbox series

Patch

diff --git a/drivers/thermal/rcar_gen3_thermal.c b/drivers/thermal/rcar_gen3_thermal.c
index 7aed533..85fc4b2 100644
--- a/drivers/thermal/rcar_gen3_thermal.c
+++ b/drivers/thermal/rcar_gen3_thermal.c
@@ -447,11 +447,32 @@  static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 	return ret;
 }
 
+static int rcar_gen3_thermal_standby(struct rcar_gen3_thermal_priv* priv)
+{
+	unsigned int i;
+	u32 reg_val;
+
+	for (i = 0; i < TSC_MAX_NUM; i++) {
+		struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
+
+		rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, 0);
+		rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
+
+		reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
+		rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val & ~THCTR_THSST);
+
+
+		usleep_range(1000, 2000);
+	}
+
+	return 0;
+}
+
 static int __maybe_unused rcar_gen3_thermal_suspend(struct device *dev)
 {
 	struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
 
-	rcar_thermal_irq_set(priv, false);
+	rcar_gen3_thermal_standby(priv);
 
 	return 0;
 }