[PATCH] thermal: rcar_gen3_thermal: Do not use interrupts for normal operation

[PATCH] thermal: rcar_gen3_thermal: Do not use interrupts for normal operation

[Niklas Söderlund]

Remove the usage of interrupts for the normal temperature operation and
depend on the polling performed by the thermal core. This is done to
prepare to use the interrupts as they are intended to trigger once
specific trip points are passed and not to react to temperature changes
in the normal operational range.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
---
 drivers/thermal/rcar_gen3_thermal.c | 108 +---------------------------
 1 file changed, 2 insertions(+), 106 deletions(-)

diff --git a/drivers/thermal/rcar_gen3_thermal.c b/drivers/thermal/rcar_gen3_thermal.c
index 0dd47dca3e771256..94f2c133a47f66b6 100644
--- a/drivers/thermal/rcar_gen3_thermal.c
+++ b/drivers/thermal/rcar_gen3_thermal.c
@@ -188,70 +188,10 @@ static int rcar_gen3_thermal_get_temp(void *devdata, int *temp)
 	return 0;
 }
 
-static int rcar_gen3_thermal_mcelsius_to_temp(struct rcar_gen3_thermal_tsc *tsc,
-					      int mcelsius)
-{
-	int celsius, val;
-
-	celsius = DIV_ROUND_CLOSEST(mcelsius, 1000);
-	if (celsius <= INT_FIXPT(tsc->tj_t))
-		val = celsius * tsc->coef.a1 + tsc->coef.b1;
-	else
-		val = celsius * tsc->coef.a2 + tsc->coef.b2;
-
-	return INT_FIXPT(val);
-}
-
-static int rcar_gen3_thermal_update_range(struct rcar_gen3_thermal_tsc *tsc)
-{
-	int temperature, low, high;
-
-	rcar_gen3_thermal_get_temp(tsc, &temperature);
-
-	low = temperature - MCELSIUS(1);
-	high = temperature + MCELSIUS(1);
-
-	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP1,
-				rcar_gen3_thermal_mcelsius_to_temp(tsc, low));
-
-	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP2,
-				rcar_gen3_thermal_mcelsius_to_temp(tsc, high));
-
-	return 0;
-}
-
 static const struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = {
 	.get_temp	= rcar_gen3_thermal_get_temp,
 };
 
-static void rcar_thermal_irq_set(struct rcar_gen3_thermal_priv *priv, bool on)
-{
-	unsigned int i;
-	u32 val = on ? IRQ_TEMPD1 | IRQ_TEMP2 : 0;
-
-	for (i = 0; i < priv->num_tscs; i++)
-		rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQMSK, val);
-}
-
-static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data)
-{
-	struct rcar_gen3_thermal_priv *priv = data;
-	u32 status;
-	int i;
-
-	for (i = 0; i < priv->num_tscs; i++) {
-		status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR);
-		rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0);
-		if (status) {
-			rcar_gen3_thermal_update_range(priv->tscs[i]);
-			thermal_zone_device_update(priv->tscs[i]->zone,
-						   THERMAL_EVENT_UNSPECIFIED);
-		}
-	}
-
-	return IRQ_HANDLED;
-}
-
 static const struct soc_device_attribute r8a7795es1[] = {
 	{ .soc_id = "r8a7795", .revision = "ES1.*" },
 	{ /* sentinel */ }
@@ -268,7 +208,6 @@ static void rcar_gen3_thermal_init_r8a7795es1(struct rcar_gen3_thermal_tsc *tsc)
 
 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
-	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
 
 	rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
 				CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN);
@@ -294,7 +233,6 @@ static void rcar_gen3_thermal_init(struct rcar_gen3_thermal_tsc *tsc)
 
 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0);
 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
-	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
 
 	reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
 	reg_val |= THCTR_THSST;
@@ -345,9 +283,6 @@ MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);
 static int rcar_gen3_thermal_remove(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
-	struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
-
-	rcar_thermal_irq_set(priv, false);
 
 	pm_runtime_put(dev);
 	pm_runtime_disable(dev);
@@ -369,8 +304,7 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 	const int *rcar_gen3_ths_tj_1 = of_device_get_match_data(dev);
 	struct resource *res;
 	struct thermal_zone_device *zone;
-	int ret, irq, i;
-	char *irqname;
+	int ret, i;
 
 	/* default values if FUSEs are missing */
 	/* TODO: Read values from hardware on supported platforms */
@@ -386,28 +320,6 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, priv);
 
-	/*
-	 * Request 2 (of the 3 possible) IRQs, the driver only needs to
-	 * to trigger on the low and high trip points of the current
-	 * temp window at this point.
-	 */
-	for (i = 0; i < 2; i++) {
-		irq = platform_get_irq(pdev, i);
-		if (irq < 0)
-			return irq;
-
-		irqname = devm_kasprintf(dev, GFP_KERNEL, "%s:ch%d",
-					 dev_name(dev), i);
-		if (!irqname)
-			return -ENOMEM;
-
-		ret = devm_request_threaded_irq(dev, irq, NULL,
-						rcar_gen3_thermal_irq,
-						IRQF_ONESHOT, irqname, priv);
-		if (ret)
-			return ret;
-	}
-
 	pm_runtime_enable(dev);
 	pm_runtime_get_sync(dev);
 
@@ -459,8 +371,6 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 		if (ret < 0)
 			goto error_unregister;
 
-		rcar_gen3_thermal_update_range(tsc);
-
 		dev_info(dev, "TSC%d: Loaded %d trip points\n", i, ret);
 	}
 
@@ -471,8 +381,6 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 		goto error_unregister;
 	}
 
-	rcar_thermal_irq_set(priv, true);
-
 	return 0;
 
 error_unregister:
@@ -481,15 +389,6 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 	return ret;
 }
 
-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);
-
-	return 0;
-}
-
 static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
 {
 	struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
@@ -499,15 +398,12 @@ static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
 		struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
 
 		priv->thermal_init(tsc);
-		rcar_gen3_thermal_update_range(tsc);
 	}
 
-	rcar_thermal_irq_set(priv, true);
-
 	return 0;
 }
 
-static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, rcar_gen3_thermal_suspend,
+static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, NULL,
 			 rcar_gen3_thermal_resume);
 
 static struct platform_driver rcar_gen3_thermal_driver = {
-- 
2.29.2

Re: [PATCH] thermal: rcar_gen3_thermal: Do not use interrupts for normal operation

[Daniel Lezcano]

On 26/11/2020 23:09, Niklas Söderlund wrote:
> Remove the usage of interrupts for the normal temperature operation and
> depend on the polling performed by the thermal core. This is done to
> prepare to use the interrupts as they are intended to trigger once
> specific trip points are passed and not to react to temperature changes
> in the normal operational range.

I'm not sure to understand the change. Is it not more interesting to
have the polling mode disabled for PM reasons and let the interrupt to
fire at the first trip point so the mitigation happens then with the
polling passive ?

> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> ---
>  drivers/thermal/rcar_gen3_thermal.c | 108 +---------------------------
>  1 file changed, 2 insertions(+), 106 deletions(-)
> 
> diff --git a/drivers/thermal/rcar_gen3_thermal.c b/drivers/thermal/rcar_gen3_thermal.c
> index 0dd47dca3e771256..94f2c133a47f66b6 100644
> --- a/drivers/thermal/rcar_gen3_thermal.c
> +++ b/drivers/thermal/rcar_gen3_thermal.c
> @@ -188,70 +188,10 @@ static int rcar_gen3_thermal_get_temp(void *devdata, int *temp)
>  	return 0;
>  }
>  
> -static int rcar_gen3_thermal_mcelsius_to_temp(struct rcar_gen3_thermal_tsc *tsc,
> -					      int mcelsius)
> -{
> -	int celsius, val;
> -
> -	celsius = DIV_ROUND_CLOSEST(mcelsius, 1000);
> -	if (celsius <= INT_FIXPT(tsc->tj_t))
> -		val = celsius * tsc->coef.a1 + tsc->coef.b1;
> -	else
> -		val = celsius * tsc->coef.a2 + tsc->coef.b2;
> -
> -	return INT_FIXPT(val);
> -}
> -
> -static int rcar_gen3_thermal_update_range(struct rcar_gen3_thermal_tsc *tsc)
> -{
> -	int temperature, low, high;
> -
> -	rcar_gen3_thermal_get_temp(tsc, &temperature);
> -
> -	low = temperature - MCELSIUS(1);
> -	high = temperature + MCELSIUS(1);
> -
> -	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP1,
> -				rcar_gen3_thermal_mcelsius_to_temp(tsc, low));
> -
> -	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP2,
> -				rcar_gen3_thermal_mcelsius_to_temp(tsc, high));
> -
> -	return 0;
> -}
> -
>  static const struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = {
>  	.get_temp	= rcar_gen3_thermal_get_temp,
>  };
>  
> -static void rcar_thermal_irq_set(struct rcar_gen3_thermal_priv *priv, bool on)
> -{
> -	unsigned int i;
> -	u32 val = on ? IRQ_TEMPD1 | IRQ_TEMP2 : 0;
> -
> -	for (i = 0; i < priv->num_tscs; i++)
> -		rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQMSK, val);
> -}
> -
> -static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data)
> -{
> -	struct rcar_gen3_thermal_priv *priv = data;
> -	u32 status;
> -	int i;
> -
> -	for (i = 0; i < priv->num_tscs; i++) {
> -		status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR);
> -		rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0);
> -		if (status) {
> -			rcar_gen3_thermal_update_range(priv->tscs[i]);
> -			thermal_zone_device_update(priv->tscs[i]->zone,
> -						   THERMAL_EVENT_UNSPECIFIED);
> -		}
> -	}
> -
> -	return IRQ_HANDLED;
> -}
> -
>  static const struct soc_device_attribute r8a7795es1[] = {
>  	{ .soc_id = "r8a7795", .revision = "ES1.*" },
>  	{ /* sentinel */ }
> @@ -268,7 +208,6 @@ static void rcar_gen3_thermal_init_r8a7795es1(struct rcar_gen3_thermal_tsc *tsc)
>  
>  	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
>  	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
> -	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
>  
>  	rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
>  				CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN);
> @@ -294,7 +233,6 @@ static void rcar_gen3_thermal_init(struct rcar_gen3_thermal_tsc *tsc)
>  
>  	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0);
>  	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
> -	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
>  
>  	reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
>  	reg_val |= THCTR_THSST;
> @@ -345,9 +283,6 @@ MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);
>  static int rcar_gen3_thermal_remove(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
> -	struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
> -
> -	rcar_thermal_irq_set(priv, false);
>  
>  	pm_runtime_put(dev);
>  	pm_runtime_disable(dev);
> @@ -369,8 +304,7 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
>  	const int *rcar_gen3_ths_tj_1 = of_device_get_match_data(dev);
>  	struct resource *res;
>  	struct thermal_zone_device *zone;
> -	int ret, irq, i;
> -	char *irqname;
> +	int ret, i;
>  
>  	/* default values if FUSEs are missing */
>  	/* TODO: Read values from hardware on supported platforms */
> @@ -386,28 +320,6 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
>  
>  	platform_set_drvdata(pdev, priv);
>  
> -	/*
> -	 * Request 2 (of the 3 possible) IRQs, the driver only needs to
> -	 * to trigger on the low and high trip points of the current
> -	 * temp window at this point.
> -	 */
> -	for (i = 0; i < 2; i++) {
> -		irq = platform_get_irq(pdev, i);
> -		if (irq < 0)
> -			return irq;
> -
> -		irqname = devm_kasprintf(dev, GFP_KERNEL, "%s:ch%d",
> -					 dev_name(dev), i);
> -		if (!irqname)
> -			return -ENOMEM;
> -
> -		ret = devm_request_threaded_irq(dev, irq, NULL,
> -						rcar_gen3_thermal_irq,
> -						IRQF_ONESHOT, irqname, priv);
> -		if (ret)
> -			return ret;
> -	}
> -
>  	pm_runtime_enable(dev);
>  	pm_runtime_get_sync(dev);
>  
> @@ -459,8 +371,6 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
>  		if (ret < 0)
>  			goto error_unregister;
>  
> -		rcar_gen3_thermal_update_range(tsc);
> -
>  		dev_info(dev, "TSC%d: Loaded %d trip points\n", i, ret);
>  	}
>  
> @@ -471,8 +381,6 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
>  		goto error_unregister;
>  	}
>  
> -	rcar_thermal_irq_set(priv, true);
> -
>  	return 0;
>  
>  error_unregister:
> @@ -481,15 +389,6 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
>  	return ret;
>  }
>  
> -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);
> -
> -	return 0;
> -}
> -
>  static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
>  {
>  	struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
> @@ -499,15 +398,12 @@ static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
>  		struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
>  
>  		priv->thermal_init(tsc);
> -		rcar_gen3_thermal_update_range(tsc);
>  	}
>  
> -	rcar_thermal_irq_set(priv, true);
> -
>  	return 0;
>  }
>  
> -static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, rcar_gen3_thermal_suspend,
> +static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, NULL,
>  			 rcar_gen3_thermal_resume);
>  
>  static struct platform_driver rcar_gen3_thermal_driver = {
> 


-- 
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog

Re: [PATCH] thermal: rcar_gen3_thermal: Do not use interrupts for normal operation

[Niklas Söderlund]

Hi Daniel,

Thanks for your comments.

On 2020-11-30 09:15:00 +0100, Daniel Lezcano wrote:
> On 26/11/2020 23:09, Niklas Söderlund wrote:
> > Remove the usage of interrupts for the normal temperature operation and
> > depend on the polling performed by the thermal core. This is done to
> > prepare to use the interrupts as they are intended to trigger once
> > specific trip points are passed and not to react to temperature changes
> > in the normal operational range.
> 
> I'm not sure to understand the change. Is it not more interesting to
> have the polling mode disabled for PM reasons and let the interrupt to
> fire at the first trip point so the mitigation happens then with the
> polling passive ?

I agree and this is one of two goals I have with this change, in the 
long run. The other is to be able support SoC models where the 
interrupts may not be accessible.

The change in this patch is to stop using the interrupts to fire as soon 
as the temp moves +/- 1 degree C, see rcar_gen3_thermal_update_range().  
When I wrote that code I had misunderstood how things should be done and 
thought I should use the interrupts as a substitute to the polling done 
by the core and generate a THERMAL_EVENT_UNSPECIFIED as soon as the temp 
changed, see rcar_gen3_thermal_irq().

The way I understand it today is that I should instead setup the 
interrupts to fire if the temp moves over a trip point, in my case 
described in DT to allow the system to be informed of this as you 
describe above.

In this firs change I'm simply removing my incorrect usage of interrupts 
that I in future changes will add back in an correct usage pattern while 
at the same time making interrupts optional to support SoCs where the 
may not be available.

Does this make sens or have I got the idea wrong?

> 
> > Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> > ---
> >  drivers/thermal/rcar_gen3_thermal.c | 108 +---------------------------
> >  1 file changed, 2 insertions(+), 106 deletions(-)
> > 
> > diff --git a/drivers/thermal/rcar_gen3_thermal.c b/drivers/thermal/rcar_gen3_thermal.c
> > index 0dd47dca3e771256..94f2c133a47f66b6 100644
> > --- a/drivers/thermal/rcar_gen3_thermal.c
> > +++ b/drivers/thermal/rcar_gen3_thermal.c
> > @@ -188,70 +188,10 @@ static int rcar_gen3_thermal_get_temp(void *devdata, int *temp)
> >  	return 0;
> >  }
> >  
> > -static int rcar_gen3_thermal_mcelsius_to_temp(struct rcar_gen3_thermal_tsc *tsc,
> > -					      int mcelsius)
> > -{
> > -	int celsius, val;
> > -
> > -	celsius = DIV_ROUND_CLOSEST(mcelsius, 1000);
> > -	if (celsius <= INT_FIXPT(tsc->tj_t))
> > -		val = celsius * tsc->coef.a1 + tsc->coef.b1;
> > -	else
> > -		val = celsius * tsc->coef.a2 + tsc->coef.b2;
> > -
> > -	return INT_FIXPT(val);
> > -}
> > -
> > -static int rcar_gen3_thermal_update_range(struct rcar_gen3_thermal_tsc *tsc)
> > -{
> > -	int temperature, low, high;
> > -
> > -	rcar_gen3_thermal_get_temp(tsc, &temperature);
> > -
> > -	low = temperature - MCELSIUS(1);
> > -	high = temperature + MCELSIUS(1);
> > -
> > -	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP1,
> > -				rcar_gen3_thermal_mcelsius_to_temp(tsc, low));
> > -
> > -	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP2,
> > -				rcar_gen3_thermal_mcelsius_to_temp(tsc, high));
> > -
> > -	return 0;
> > -}
> > -
> >  static const struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = {
> >  	.get_temp	= rcar_gen3_thermal_get_temp,
> >  };
> >  
> > -static void rcar_thermal_irq_set(struct rcar_gen3_thermal_priv *priv, bool on)
> > -{
> > -	unsigned int i;
> > -	u32 val = on ? IRQ_TEMPD1 | IRQ_TEMP2 : 0;
> > -
> > -	for (i = 0; i < priv->num_tscs; i++)
> > -		rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQMSK, val);
> > -}
> > -
> > -static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data)
> > -{
> > -	struct rcar_gen3_thermal_priv *priv = data;
> > -	u32 status;
> > -	int i;
> > -
> > -	for (i = 0; i < priv->num_tscs; i++) {
> > -		status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR);
> > -		rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0);
> > -		if (status) {
> > -			rcar_gen3_thermal_update_range(priv->tscs[i]);
> > -			thermal_zone_device_update(priv->tscs[i]->zone,
> > -						   THERMAL_EVENT_UNSPECIFIED);
> > -		}
> > -	}
> > -
> > -	return IRQ_HANDLED;
> > -}
> > -
> >  static const struct soc_device_attribute r8a7795es1[] = {
> >  	{ .soc_id = "r8a7795", .revision = "ES1.*" },
> >  	{ /* sentinel */ }
> > @@ -268,7 +208,6 @@ static void rcar_gen3_thermal_init_r8a7795es1(struct rcar_gen3_thermal_tsc *tsc)
> >  
> >  	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
> >  	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
> > -	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
> >  
> >  	rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
> >  				CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN);
> > @@ -294,7 +233,6 @@ static void rcar_gen3_thermal_init(struct rcar_gen3_thermal_tsc *tsc)
> >  
> >  	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0);
> >  	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
> > -	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
> >  
> >  	reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
> >  	reg_val |= THCTR_THSST;
> > @@ -345,9 +283,6 @@ MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);
> >  static int rcar_gen3_thermal_remove(struct platform_device *pdev)
> >  {
> >  	struct device *dev = &pdev->dev;
> > -	struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
> > -
> > -	rcar_thermal_irq_set(priv, false);
> >  
> >  	pm_runtime_put(dev);
> >  	pm_runtime_disable(dev);
> > @@ -369,8 +304,7 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
> >  	const int *rcar_gen3_ths_tj_1 = of_device_get_match_data(dev);
> >  	struct resource *res;
> >  	struct thermal_zone_device *zone;
> > -	int ret, irq, i;
> > -	char *irqname;
> > +	int ret, i;
> >  
> >  	/* default values if FUSEs are missing */
> >  	/* TODO: Read values from hardware on supported platforms */
> > @@ -386,28 +320,6 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
> >  
> >  	platform_set_drvdata(pdev, priv);
> >  
> > -	/*
> > -	 * Request 2 (of the 3 possible) IRQs, the driver only needs to
> > -	 * to trigger on the low and high trip points of the current
> > -	 * temp window at this point.
> > -	 */
> > -	for (i = 0; i < 2; i++) {
> > -		irq = platform_get_irq(pdev, i);
> > -		if (irq < 0)
> > -			return irq;
> > -
> > -		irqname = devm_kasprintf(dev, GFP_KERNEL, "%s:ch%d",
> > -					 dev_name(dev), i);
> > -		if (!irqname)
> > -			return -ENOMEM;
> > -
> > -		ret = devm_request_threaded_irq(dev, irq, NULL,
> > -						rcar_gen3_thermal_irq,
> > -						IRQF_ONESHOT, irqname, priv);
> > -		if (ret)
> > -			return ret;
> > -	}
> > -
> >  	pm_runtime_enable(dev);
> >  	pm_runtime_get_sync(dev);
> >  
> > @@ -459,8 +371,6 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
> >  		if (ret < 0)
> >  			goto error_unregister;
> >  
> > -		rcar_gen3_thermal_update_range(tsc);
> > -
> >  		dev_info(dev, "TSC%d: Loaded %d trip points\n", i, ret);
> >  	}
> >  
> > @@ -471,8 +381,6 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
> >  		goto error_unregister;
> >  	}
> >  
> > -	rcar_thermal_irq_set(priv, true);
> > -
> >  	return 0;
> >  
> >  error_unregister:
> > @@ -481,15 +389,6 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
> >  	return ret;
> >  }
> >  
> > -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);
> > -
> > -	return 0;
> > -}
> > -
> >  static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
> >  {
> >  	struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
> > @@ -499,15 +398,12 @@ static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
> >  		struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
> >  
> >  		priv->thermal_init(tsc);
> > -		rcar_gen3_thermal_update_range(tsc);
> >  	}
> >  
> > -	rcar_thermal_irq_set(priv, true);
> > -
> >  	return 0;
> >  }
> >  
> > -static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, rcar_gen3_thermal_suspend,
> > +static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, NULL,
> >  			 rcar_gen3_thermal_resume);
> >  
> >  static struct platform_driver rcar_gen3_thermal_driver = {
> > 
> 
> 
> -- 
> <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
> 
> Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
> <http://twitter.com/#!/linaroorg> Twitter |
> <http://www.linaro.org/linaro-blog/> Blog

-- 
Regards,
Niklas Söderlund

Re: [PATCH] thermal: rcar_gen3_thermal: Do not use interrupts for normal operation

[Daniel Lezcano]

On 30/11/2020 12:49, Niklas Söderlund wrote:
> Hi Daniel,
> 
> Thanks for your comments.
> 
> On 2020-11-30 09:15:00 +0100, Daniel Lezcano wrote:
>> On 26/11/2020 23:09, Niklas Söderlund wrote:
>>> Remove the usage of interrupts for the normal temperature operation and
>>> depend on the polling performed by the thermal core. This is done to
>>> prepare to use the interrupts as they are intended to trigger once
>>> specific trip points are passed and not to react to temperature changes
>>> in the normal operational range.
>>
>> I'm not sure to understand the change. Is it not more interesting to
>> have the polling mode disabled for PM reasons and let the interrupt to
>> fire at the first trip point so the mitigation happens then with the
>> polling passive ?
> 
> I agree and this is one of two goals I have with this change, in the 
> long run. The other is to be able support SoC models where the 
> interrupts may not be accessible.
> 
> The change in this patch is to stop using the interrupts to fire as soon 
> as the temp moves +/- 1 degree C, see rcar_gen3_thermal_update_range().  
> When I wrote that code I had misunderstood how things should be done and 
> thought I should use the interrupts as a substitute to the polling done 
> by the core and generate a THERMAL_EVENT_UNSPECIFIED as soon as the temp 
> changed, see rcar_gen3_thermal_irq().
> 
> The way I understand it today is that I should instead setup the 
> interrupts to fire if the temp moves over a trip point, in my case 
> described in DT to allow the system to be informed of this as you 
> describe above.
> 
> In this firs change I'm simply removing my incorrect usage of interrupts 
> that I in future changes will add back in an correct usage pattern while 
> at the same time making interrupts optional to support SoCs where the 
> may not be available.
> 
> Does this make sens or have I got the idea wrong?

Ah, ok. I understand better now, thanks for the clarification.

The interrupt mode implementation is wrong, so you remove it and switch
to the polling mode until the interrupt is re-implemented in the correct
way.



-- 
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog

[thermal: thermal/next] thermal: rcar_gen3_thermal: Do not use interrupts for normal operation

[thermal-bot for Niklas Söderlund]

The following commit has been merged into the thermal/next branch of thermal:

Commit-ID:     1b57b9597c779f0a20c5837abec31f600240496b
Gitweb:        https://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux.git//1b57b9597c779f0a20c5837abec31f600240496b
Author:        Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
AuthorDate:    Thu, 26 Nov 2020 23:09:23 +01:00
Committer:     Daniel Lezcano <daniel.lezcano@linaro.org>
CommitterDate: Mon, 30 Nov 2020 16:38:27 +01:00

thermal: rcar_gen3_thermal: Do not use interrupts for normal operation

Remove the usage of interrupts for the normal temperature operation and
depend on the polling performed by the thermal core. This is done to
prepare to use the interrupts as they are intended to trigger once
specific trip points are passed and not to react to temperature changes
in the normal operational range.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20201126220923.3107213-1-niklas.soderlund+renesas@ragnatech.se
---
 drivers/thermal/rcar_gen3_thermal.c | 108 +---------------------------
 1 file changed, 2 insertions(+), 106 deletions(-)

diff --git a/drivers/thermal/rcar_gen3_thermal.c b/drivers/thermal/rcar_gen3_thermal.c
index 0dd47dc..94f2c13 100644
--- a/drivers/thermal/rcar_gen3_thermal.c
+++ b/drivers/thermal/rcar_gen3_thermal.c
@@ -188,70 +188,10 @@ static int rcar_gen3_thermal_get_temp(void *devdata, int *temp)
 	return 0;
 }
 
-static int rcar_gen3_thermal_mcelsius_to_temp(struct rcar_gen3_thermal_tsc *tsc,
-					      int mcelsius)
-{
-	int celsius, val;
-
-	celsius = DIV_ROUND_CLOSEST(mcelsius, 1000);
-	if (celsius <= INT_FIXPT(tsc->tj_t))
-		val = celsius * tsc->coef.a1 + tsc->coef.b1;
-	else
-		val = celsius * tsc->coef.a2 + tsc->coef.b2;
-
-	return INT_FIXPT(val);
-}
-
-static int rcar_gen3_thermal_update_range(struct rcar_gen3_thermal_tsc *tsc)
-{
-	int temperature, low, high;
-
-	rcar_gen3_thermal_get_temp(tsc, &temperature);
-
-	low = temperature - MCELSIUS(1);
-	high = temperature + MCELSIUS(1);
-
-	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP1,
-				rcar_gen3_thermal_mcelsius_to_temp(tsc, low));
-
-	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP2,
-				rcar_gen3_thermal_mcelsius_to_temp(tsc, high));
-
-	return 0;
-}
-
 static const struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = {
 	.get_temp	= rcar_gen3_thermal_get_temp,
 };
 
-static void rcar_thermal_irq_set(struct rcar_gen3_thermal_priv *priv, bool on)
-{
-	unsigned int i;
-	u32 val = on ? IRQ_TEMPD1 | IRQ_TEMP2 : 0;
-
-	for (i = 0; i < priv->num_tscs; i++)
-		rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQMSK, val);
-}
-
-static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data)
-{
-	struct rcar_gen3_thermal_priv *priv = data;
-	u32 status;
-	int i;
-
-	for (i = 0; i < priv->num_tscs; i++) {
-		status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR);
-		rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0);
-		if (status) {
-			rcar_gen3_thermal_update_range(priv->tscs[i]);
-			thermal_zone_device_update(priv->tscs[i]->zone,
-						   THERMAL_EVENT_UNSPECIFIED);
-		}
-	}
-
-	return IRQ_HANDLED;
-}
-
 static const struct soc_device_attribute r8a7795es1[] = {
 	{ .soc_id = "r8a7795", .revision = "ES1.*" },
 	{ /* sentinel */ }
@@ -268,7 +208,6 @@ static void rcar_gen3_thermal_init_r8a7795es1(struct rcar_gen3_thermal_tsc *tsc)
 
 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
-	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
 
 	rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
 				CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN);
@@ -294,7 +233,6 @@ static void rcar_gen3_thermal_init(struct rcar_gen3_thermal_tsc *tsc)
 
 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0);
 	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
-	rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN, IRQ_TEMPD1 | IRQ_TEMP2);
 
 	reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
 	reg_val |= THCTR_THSST;
@@ -345,9 +283,6 @@ MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);
 static int rcar_gen3_thermal_remove(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
-	struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
-
-	rcar_thermal_irq_set(priv, false);
 
 	pm_runtime_put(dev);
 	pm_runtime_disable(dev);
@@ -369,8 +304,7 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 	const int *rcar_gen3_ths_tj_1 = of_device_get_match_data(dev);
 	struct resource *res;
 	struct thermal_zone_device *zone;
-	int ret, irq, i;
-	char *irqname;
+	int ret, i;
 
 	/* default values if FUSEs are missing */
 	/* TODO: Read values from hardware on supported platforms */
@@ -386,28 +320,6 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, priv);
 
-	/*
-	 * Request 2 (of the 3 possible) IRQs, the driver only needs to
-	 * to trigger on the low and high trip points of the current
-	 * temp window at this point.
-	 */
-	for (i = 0; i < 2; i++) {
-		irq = platform_get_irq(pdev, i);
-		if (irq < 0)
-			return irq;
-
-		irqname = devm_kasprintf(dev, GFP_KERNEL, "%s:ch%d",
-					 dev_name(dev), i);
-		if (!irqname)
-			return -ENOMEM;
-
-		ret = devm_request_threaded_irq(dev, irq, NULL,
-						rcar_gen3_thermal_irq,
-						IRQF_ONESHOT, irqname, priv);
-		if (ret)
-			return ret;
-	}
-
 	pm_runtime_enable(dev);
 	pm_runtime_get_sync(dev);
 
@@ -459,8 +371,6 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 		if (ret < 0)
 			goto error_unregister;
 
-		rcar_gen3_thermal_update_range(tsc);
-
 		dev_info(dev, "TSC%d: Loaded %d trip points\n", i, ret);
 	}
 
@@ -471,8 +381,6 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 		goto error_unregister;
 	}
 
-	rcar_thermal_irq_set(priv, true);
-
 	return 0;
 
 error_unregister:
@@ -481,15 +389,6 @@ error_unregister:
 	return ret;
 }
 
-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);
-
-	return 0;
-}
-
 static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
 {
 	struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
@@ -499,15 +398,12 @@ static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
 		struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
 
 		priv->thermal_init(tsc);
-		rcar_gen3_thermal_update_range(tsc);
 	}
 
-	rcar_thermal_irq_set(priv, true);
-
 	return 0;
 }
 
-static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, rcar_gen3_thermal_suspend,
+static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, NULL,
 			 rcar_gen3_thermal_resume);
 
 static struct platform_driver rcar_gen3_thermal_driver = {