[PATCH 0/4] thermal: stm32: driver improvements

[PATCH 0/4] thermal: stm32: driver improvements

[Pascal Paillet]

The goal of this patchset is to improve stm32 thermal driver:
* add support for multiple trip points. Currently the driver supports only
2 trip points.
* rework interrupt management to avoid receiving hundreds of
interrupts when the temperature is close to a low threshold.
* fix a mistake regarding the role of an engineering value.
* suppress passive trip point on stm32mp157c because it is useless.

Pascal Paillet (4):
  thermal: stm32: implement set_trips callback
  thermal: stm32: fix IRQ flood on low threshold
  thermal: stm32: fix engineering calibration value
  ARM: dts: stm32: remove thermal passive trip point on stm32mp157c

 arch/arm/boot/dts/stm32mp157c.dtsi |   6 -
 drivers/thermal/st/stm_thermal.c   | 441 +++++++++--------------------
 2 files changed, 138 insertions(+), 309 deletions(-)

-- 
2.17.1


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[PATCH 1/4] thermal: stm32: implement set_trips callback

[Pascal Paillet]

Implement set_trips() so that the trip points are managed by the thermal
framework. The user is free to define any trip points he needs.
Simplify interrupt handling.


Signed-off-by: Pascal Paillet <p.paillet@st.com>
Change-Id: I2929d4fa5b4c5dca45cec7cb3b93fffc277394d2
---
 drivers/thermal/st/stm_thermal.c | 370 +++++++++++--------------------
 1 file changed, 125 insertions(+), 245 deletions(-)

diff --git a/drivers/thermal/st/stm_thermal.c b/drivers/thermal/st/stm_thermal.c
index cf9ddc52f30e..0aae1cc14235 100644
--- a/drivers/thermal/st/stm_thermal.c
+++ b/drivers/thermal/st/stm_thermal.c
@@ -30,7 +30,7 @@
 #define DTS_DR_OFFSET		0x1C
 #define DTS_SR_OFFSET		0x20
 #define DTS_ITENR_OFFSET	0x24
-#define DTS_CIFR_OFFSET		0x28
+#define DTS_ICIFR_OFFSET	0x28
 
 /* DTS_CFGR1 register mask definitions */
 #define HSREF_CLK_DIV_MASK	GENMASK(30, 24)
@@ -51,10 +51,17 @@
 /* DTS_DR register mask definitions */
 #define TS1_MFREQ_MASK		GENMASK(15, 0)
 
+/* DTS_ITENR register mask definitions */
+#define ITENR_MASK		(GENMASK(2, 0) | GENMASK(6, 4))
+
+/* DTS_ICIFR register mask definitions */
+#define ICIFR_MASK		(GENMASK(2, 0) | GENMASK(6, 4))
+
 /* Less significant bit position definitions */
 #define TS1_T0_POS		16
 #define TS1_SMP_TIME_POS	16
 #define TS1_HITTHD_POS		16
+#define TS1_LITTHD_POS		0
 #define HSREF_CLK_DIV_POS	24
 
 /* DTS_CFGR1 bit definitions */
@@ -91,44 +98,59 @@ struct stm_thermal_sensor {
 	struct thermal_zone_device *th_dev;
 	enum thermal_device_mode mode;
 	struct clk *clk;
-	int high_temp;
-	int low_temp;
-	int temp_critical;
-	int temp_passive;
-	unsigned int low_temp_enabled;
-	int num_trips;
 	int irq;
-	unsigned int irq_enabled;
 	void __iomem *base;
 	int t0, fmt0, ramp_coeff;
+	int low_en, high_en;
 };
 
-static irqreturn_t stm_thermal_alarm_irq(int irq, void *sdata)
+static void stm_thermal_disable_irq(struct stm_thermal_sensor *sensor)
 {
-	struct stm_thermal_sensor *sensor = sdata;
+	u32 itenr;
+
+	/* Disable IT generation */
+	itenr = readl_relaxed(sensor->base + DTS_ITENR_OFFSET);
+	itenr &= ~ITENR_MASK;
+	writel_relaxed(itenr, sensor->base + DTS_ITENR_OFFSET);
+}
+
+static void stm_thermal_set_irq_state(struct stm_thermal_sensor *sensor)
+{
+	u32 itenr;
+
+	dev_dbg(sensor->dev, "low:%d high:%d\n", sensor->low_en,
+		sensor->high_en);
+
+	/* Disable IT generation for low and high thresholds */
+	itenr = readl_relaxed(sensor->base + DTS_ITENR_OFFSET);
+	itenr &= ~(LOW_THRESHOLD | HIGH_THRESHOLD);
+
+	if (sensor->low_en)
+		itenr |= HIGH_THRESHOLD;
 
-	disable_irq_nosync(irq);
-	sensor->irq_enabled = false;
+	if (sensor->high_en)
+		itenr |= LOW_THRESHOLD;
 
-	return IRQ_WAKE_THREAD;
+	/* Enable interrupts */
+	writel_relaxed(itenr, sensor->base + DTS_ITENR_OFFSET);
 }
 
 static irqreturn_t stm_thermal_alarm_irq_thread(int irq, void *sdata)
 {
-	u32 value;
 	struct stm_thermal_sensor *sensor = sdata;
 
-	/* read IT reason in SR and clear flags */
-	value = readl_relaxed(sensor->base + DTS_SR_OFFSET);
-
-	if ((value & LOW_THRESHOLD) == LOW_THRESHOLD)
-		writel_relaxed(LOW_THRESHOLD, sensor->base + DTS_CIFR_OFFSET);
+	dev_dbg(sensor->dev, "sr:%d\n",
+		readl_relaxed(sensor->base + DTS_SR_OFFSET));
 
-	if ((value & HIGH_THRESHOLD) == HIGH_THRESHOLD)
-		writel_relaxed(HIGH_THRESHOLD, sensor->base + DTS_CIFR_OFFSET);
+	stm_thermal_disable_irq(sensor);
 
 	thermal_zone_device_update(sensor->th_dev, THERMAL_EVENT_UNSPECIFIED);
 
+	stm_thermal_set_irq_state(sensor);
+
+	/* Acknoledge all DTS irqs */
+	writel_relaxed(ICIFR_MASK, sensor->base + DTS_ICIFR_OFFSET);
+
 	return IRQ_HANDLED;
 }
 
@@ -160,6 +182,8 @@ static int stm_sensor_power_on(struct stm_thermal_sensor *sensor)
 	writel_relaxed(value, sensor->base +
 		       DTS_CFGR1_OFFSET);
 
+	sensor->mode = THERMAL_DEVICE_ENABLED;
+
 	return 0;
 }
 
@@ -167,6 +191,8 @@ static int stm_sensor_power_off(struct stm_thermal_sensor *sensor)
 {
 	u32 value;
 
+	sensor->mode = THERMAL_DEVICE_DISABLED;
+
 	/* Stop measuring */
 	value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET);
 	value &= ~TS1_START;
@@ -285,118 +311,7 @@ static int stm_thermal_calculate_threshold(struct stm_thermal_sensor *sensor,
 
 	*th *= sampling_time;
 
-	return 0;
-}
-
-static int stm_thermal_set_threshold(struct stm_thermal_sensor *sensor)
-{
-	u32 value, th;
-	int ret;
-
-	value = readl_relaxed(sensor->base + DTS_ITR1_OFFSET);
-
-	/* Erase threshold content */
-	value &= ~(TS1_LITTHD_MASK | TS1_HITTHD_MASK);
-
-	/* Retrieve the sample threshold number th for a given temperature */
-	ret = stm_thermal_calculate_threshold(sensor, sensor->high_temp, &th);
-	if (ret)
-		return ret;
-
-	value |= th & TS1_LITTHD_MASK;
-
-	if (sensor->low_temp_enabled) {
-		/* Retrieve the sample threshold */
-		ret = stm_thermal_calculate_threshold(sensor, sensor->low_temp,
-						      &th);
-		if (ret)
-			return ret;
-
-		value |= (TS1_HITTHD_MASK  & (th << TS1_HITTHD_POS));
-	}
-
-	/* Write value on the Low interrupt threshold */
-	writel_relaxed(value, sensor->base + DTS_ITR1_OFFSET);
-
-	return 0;
-}
-
-/* Disable temperature interrupt */
-static int stm_disable_irq(struct stm_thermal_sensor *sensor)
-{
-	u32 value;
-
-	/* Disable IT generation for low and high thresholds */
-	value = readl_relaxed(sensor->base + DTS_ITENR_OFFSET);
-	writel_relaxed(value & ~(LOW_THRESHOLD | HIGH_THRESHOLD),
-		       sensor->base + DTS_ITENR_OFFSET);
-
-	dev_dbg(sensor->dev, "%s: IT disabled on sensor side", __func__);
-
-	return 0;
-}
-
-/* Enable temperature interrupt */
-static int stm_enable_irq(struct stm_thermal_sensor *sensor)
-{
-	u32 value;
-
-	/*
-	 * Code below enables High temperature threshold using a low threshold
-	 * sampling value
-	 */
-
-	/* Make sure LOW_THRESHOLD IT is clear before enabling */
-	writel_relaxed(LOW_THRESHOLD, sensor->base + DTS_CIFR_OFFSET);
-
-	/* Enable IT generation for low threshold */
-	value = readl_relaxed(sensor->base + DTS_ITENR_OFFSET);
-	value |= LOW_THRESHOLD;
-
-	/* Enable the low temperature threshold if needed */
-	if (sensor->low_temp_enabled) {
-		/* Make sure HIGH_THRESHOLD IT is clear before enabling */
-		writel_relaxed(HIGH_THRESHOLD, sensor->base + DTS_CIFR_OFFSET);
-
-		/* Enable IT generation for high threshold */
-		value |= HIGH_THRESHOLD;
-	}
-
-	/* Enable thresholds */
-	writel_relaxed(value, sensor->base + DTS_ITENR_OFFSET);
-
-	dev_dbg(sensor->dev, "%s: IT enabled on sensor side", __func__);
-
-	return 0;
-}
-
-static int stm_thermal_update_threshold(struct stm_thermal_sensor *sensor)
-{
-	int ret;
-
-	sensor->mode = THERMAL_DEVICE_DISABLED;
-
-	ret = stm_sensor_power_off(sensor);
-	if (ret)
-		return ret;
-
-	ret = stm_disable_irq(sensor);
-	if (ret)
-		return ret;
-
-	ret = stm_thermal_set_threshold(sensor);
-	if (ret)
-		return ret;
-
-	ret = stm_enable_irq(sensor);
-	if (ret)
-		return ret;
-
-	ret = stm_sensor_power_on(sensor);
-	if (ret)
-		return ret;
-
-	sensor->mode = THERMAL_DEVICE_ENABLED;
+	dev_dbg(sensor->dev, "freqM=%d Hz, threshold=0x%x", freqM, *th);
 
 	return 0;
 }
@@ -440,42 +355,54 @@ static int stm_thermal_get_temp(void *data, int *temp)
 	*temp = mcelsius(sensor->t0 + ((freqM - sensor->fmt0) /
 			 sensor->ramp_coeff));
 
-	dev_dbg(sensor->dev, "%s: temperature = %d millicelsius",
-		__func__, *temp);
-
-	/* Update thresholds */
-	if (sensor->num_trips > 1) {
-		/* Update alarm threshold value to next higher trip point */
-		if (sensor->high_temp == sensor->temp_passive &&
-		    celsius(*temp) >= sensor->temp_passive) {
-			sensor->high_temp = sensor->temp_critical;
-			sensor->low_temp = sensor->temp_passive;
-			sensor->low_temp_enabled = true;
-			ret = stm_thermal_update_threshold(sensor);
-			if (ret)
-				return ret;
-		}
-
-		if (sensor->high_temp == sensor->temp_critical &&
-		    celsius(*temp) < sensor->temp_passive) {
-			sensor->high_temp = sensor->temp_passive;
-			sensor->low_temp_enabled = false;
-			ret = stm_thermal_update_threshold(sensor);
-			if (ret)
-				return ret;
-		}
-
-		/*
-		 * Re-enable alarm IRQ if temperature below critical
-		 * temperature
-		 */
-		if (!sensor->irq_enabled &&
-		    (celsius(*temp) < sensor->temp_critical)) {
-			sensor->irq_enabled = true;
-			enable_irq(sensor->irq);
-		}
+	dev_dbg(sensor->dev, "temperature = %d millicelsius", *temp);
+
+	return 0;
+}
+
+static int stm_thermal_set_trips(void *data, int low, int high)
+{
+	struct stm_thermal_sensor *sensor = data;
+	u32 itr1, th;
+	int ret;
+
+	dev_dbg(sensor->dev, "set trips %d <--> %d\n", low, high);
+
+	/* Erase threshold content */
+	itr1 = readl_relaxed(sensor->base + DTS_ITR1_OFFSET);
+	itr1 &= ~(TS1_LITTHD_MASK | TS1_HITTHD_MASK);
+
+	/*
+	 * Disable low-temp if "low" is too small. As per thermal framework
+	 * API, we use -INT_MAX rather than INT_MIN.
+	 */
+
+	if (low > -INT_MAX) {
+		sensor->low_en = 1;
+		ret = stm_thermal_calculate_threshold(sensor, low, &th);
+		if (ret)
+			return ret;
+
+		itr1 |= (TS1_HITTHD_MASK  & (th << TS1_HITTHD_POS));
+	} else {
+		sensor->low_en = 0;
 	}
 
+	/* Disable high-temp if "high" is too big. */
+	if (high < INT_MAX) {
+		sensor->high_en = 1;
+		ret = stm_thermal_calculate_threshold(sensor, high, &th);
+		if (ret)
+			return ret;
+
+		itr1 |= (TS1_LITTHD_MASK  & (th << TS1_LITTHD_POS));
+	} else {
+		sensor->high_en = 0;
+	}
+
+	/* Write new threshod values*/
+	writel_relaxed(itr1, sensor->base + DTS_ITR1_OFFSET);
+
 	return 0;
 }
 
@@ -493,8 +420,7 @@ static int stm_register_irq(struct stm_thermal_sensor *sensor)
 	}
 
 	ret = devm_request_threaded_irq(dev, sensor->irq,
-					stm_thermal_alarm_irq,
-					stm_thermal_alarm_irq_thread,
+					NULL, stm_thermal_alarm_irq_thread,
 					IRQF_ONESHOT,
 					dev->driver->name, sensor);
 	if (ret) {
@@ -503,8 +429,6 @@ static int stm_register_irq(struct stm_thermal_sensor *sensor)
 		return ret;
 	}
 
-	sensor->irq_enabled = true;
-
 	dev_dbg(dev, "%s: thermal IRQ registered", __func__);
 
 	return 0;
@@ -514,6 +438,8 @@ static int stm_thermal_sensor_off(struct stm_thermal_sensor *sensor)
 {
 	int ret;
 
+	stm_thermal_disable_irq(sensor);
+
 	ret = stm_sensor_power_off(sensor);
 	if (ret)
 		return ret;
@@ -526,7 +452,6 @@ static int stm_thermal_sensor_off(struct stm_thermal_sensor *sensor)
 static int stm_thermal_prepare(struct stm_thermal_sensor *sensor)
 {
 	int ret;
-	struct device *dev = sensor->dev;
 
 	ret = clk_prepare_enable(sensor->clk);
 	if (ret)
@@ -540,26 +465,8 @@ static int stm_thermal_prepare(struct stm_thermal_sensor *sensor)
 	if (ret)
 		goto thermal_unprepare;
 
-	/* Set threshold(s) for IRQ */
-	ret = stm_thermal_set_threshold(sensor);
-	if (ret)
-		goto thermal_unprepare;
-
-	ret = stm_enable_irq(sensor);
-	if (ret)
-		goto thermal_unprepare;
-
-	ret = stm_sensor_power_on(sensor);
-	if (ret) {
-		dev_err(dev, "%s: failed to power on sensor\n", __func__);
-		goto irq_disable;
-	}
-
 	return 0;
 
-irq_disable:
-	stm_disable_irq(sensor);
-
 thermal_unprepare:
 	clk_disable_unprepare(sensor->clk);
 
@@ -576,8 +483,6 @@ static int stm_thermal_suspend(struct device *dev)
 	if (ret)
 		return ret;
 
-	sensor->mode = THERMAL_DEVICE_DISABLED;
-
 	return 0;
 }
 
@@ -590,7 +495,12 @@ static int stm_thermal_resume(struct device *dev)
 	if (ret)
 		return ret;
 
-	sensor->mode = THERMAL_DEVICE_ENABLED;
+	ret = stm_sensor_power_on(sensor);
+	if (ret)
+		return ret;
+
+	thermal_zone_device_update(sensor->th_dev, THERMAL_EVENT_UNSPECIFIED);
+	stm_thermal_set_irq_state(sensor);
 
 	return 0;
 }
@@ -600,6 +510,7 @@ SIMPLE_DEV_PM_OPS(stm_thermal_pm_ops, stm_thermal_suspend, stm_thermal_resume);
 
 static const struct thermal_zone_of_device_ops stm_tz_ops = {
 	.get_temp	= stm_thermal_get_temp,
+	.set_trips	= stm_thermal_set_trips,
 };
 
 static const struct of_device_id stm_thermal_of_match[] = {
@@ -612,9 +523,8 @@ static int stm_thermal_probe(struct platform_device *pdev)
 {
 	struct stm_thermal_sensor *sensor;
 	struct resource *res;
-	const struct thermal_trip *trip;
 	void __iomem *base;
-	int ret, i;
+	int ret;
 
 	if (!pdev->dev.of_node) {
 		dev_err(&pdev->dev, "%s: device tree node not found\n",
@@ -645,10 +555,23 @@ static int stm_thermal_probe(struct platform_device *pdev)
 		return PTR_ERR(sensor->clk);
 	}
 
-	/* Register IRQ into GIC */
-	ret = stm_register_irq(sensor);
-	if (ret)
+	stm_thermal_disable_irq(sensor);
+
+	/* Clear irq flags */
+	writel_relaxed(ICIFR_MASK, sensor->base + DTS_ICIFR_OFFSET);
+
+	/* Configure and enable HW sensor */
+	ret = stm_thermal_prepare(sensor);
+	if (ret) {
+		dev_err(&pdev->dev, "Error preprare sensor: %d\n", ret);
 		return ret;
+	}
+
+	ret = stm_sensor_power_on(sensor);
+	if (ret) {
+		dev_err(&pdev->dev, "Error power on sensor: %d\n", ret);
+		return ret;
+	}
 
 	sensor->th_dev = devm_thermal_zone_of_sensor_register(&pdev->dev, 0,
 							      sensor,
@@ -661,53 +584,12 @@ static int stm_thermal_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	if (!sensor->th_dev->ops->get_crit_temp) {
-		/* Critical point must be provided */
-		ret = -EINVAL;
-		goto err_tz;
-	}
-
-	ret = sensor->th_dev->ops->get_crit_temp(sensor->th_dev,
-			&sensor->temp_critical);
-	if (ret) {
-		dev_err(&pdev->dev,
-			"Not able to read critical_temp: %d\n", ret);
+	/* Register IRQ into GIC */
+	ret = stm_register_irq(sensor);
+	if (ret)
 		goto err_tz;
-	}
 
-	sensor->temp_critical = celsius(sensor->temp_critical);
-
-	/* Set thresholds for IRQ */
-	sensor->high_temp = sensor->temp_critical;
-
-	trip = of_thermal_get_trip_points(sensor->th_dev);
-	sensor->num_trips = of_thermal_get_ntrips(sensor->th_dev);
-
-	/* Find out passive temperature if it exists */
-	for (i = (sensor->num_trips - 1); i >= 0;  i--) {
-		if (trip[i].type == THERMAL_TRIP_PASSIVE) {
-			sensor->temp_passive = celsius(trip[i].temperature);
-			/* Update high temperature threshold */
-			sensor->high_temp = sensor->temp_passive;
-			}
-	}
-
-	/*
-	 * Ensure low_temp_enabled flag is disabled.
-	 * By disabling low_temp_enabled, low threshold IT will not be
-	 * configured neither enabled because it is not needed as high
-	 * threshold is set on the lowest temperature trip point after
-	 * probe.
-	 */
-	sensor->low_temp_enabled = false;
-
-	/* Configure and enable HW sensor */
-	ret = stm_thermal_prepare(sensor);
-	if (ret) {
-		dev_err(&pdev->dev,
-			"Not able to enable sensor: %d\n", ret);
-		goto err_tz;
-	}
+	stm_thermal_set_irq_state(sensor);
 
 	/*
 	 * Thermal_zone doesn't enable hwmon as default,
@@ -718,8 +600,6 @@ static int stm_thermal_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_tz;
 
-	sensor->mode = THERMAL_DEVICE_ENABLED;
-
 	dev_info(&pdev->dev, "%s: Driver initialized successfully\n",
 		 __func__);
 
-- 
2.17.1


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Re: [PATCH 1/4] thermal: stm32: implement set_trips callback

[Daniel Lezcano]

On 29/10/2019 17:45, Pascal Paillet wrote:
> Implement set_trips() so that the trip points are managed by the thermal
> framework. The user is free to define any trip points he needs.
> Simplify interrupt handling.

The patch is touching too many things at the same time and the change
description does not help to understand the changes.

> Signed-off-by: Pascal Paillet <p.paillet@st.com>
> Change-Id: I2929d4fa5b4c5dca45cec7cb3b93fffc277394d2

Remove Change-Id

[ ... ]


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[PATCH 2/4] thermal: stm32: fix IRQ flood on low threshold

[Pascal Paillet]

Fix IRQ flood on low threshold by too ways:
- improve temperature reading resolution,
- add an hysteresis to the low threshold: on low threshold interrupt,
it is not possible to get the temperature value that has fired the
interrupt. The time to acquire a new value is enough for the CPU to
become hotter than the current low threshold.

Signed-off-by: Pascal Paillet <p.paillet@st.com>
Change-Id: I3b63b8aab38fd651a165c4e69a2d090b3c6f5db3
---
 drivers/thermal/st/stm_thermal.c | 73 +++++++++-----------------------
 1 file changed, 19 insertions(+), 54 deletions(-)

diff --git a/drivers/thermal/st/stm_thermal.c b/drivers/thermal/st/stm_thermal.c
index 0aae1cc14235..4bc1bbece0de 100644
--- a/drivers/thermal/st/stm_thermal.c
+++ b/drivers/thermal/st/stm_thermal.c
@@ -59,7 +59,6 @@
 
 /* Less significant bit position definitions */
 #define TS1_T0_POS		16
-#define TS1_SMP_TIME_POS	16
 #define TS1_HITTHD_POS		16
 #define TS1_LITTHD_POS		0
 #define HSREF_CLK_DIV_POS	24
@@ -83,15 +82,10 @@
 #define ONE_MHZ			1000000
 #define POLL_TIMEOUT		5000
 #define STARTUP_TIME		40
-#define TS1_T0_VAL0		30
-#define TS1_T0_VAL1		130
+#define TS1_T0_VAL0		30000  /* 30 celsius */
+#define TS1_T0_VAL1		130000 /* 130 celsius */
 #define NO_HW_TRIG		0
-
-/* The Thermal Framework expects millidegrees */
-#define mcelsius(temp)		((temp) * 1000)
-
-/* The Sensor expects oC degrees */
-#define celsius(temp)		((temp) / 1000)
+#define SAMPLING_TIME		15
 
 struct stm_thermal_sensor {
 	struct device *dev;
@@ -222,12 +216,8 @@ static int stm_thermal_calibration(struct stm_thermal_sensor *sensor)
 	if (!clk_freq)
 		return -EINVAL;
 
-	prescaler = 0;
-	clk_freq /= ONE_MHZ;
-	if (clk_freq) {
-		while (prescaler <= clk_freq)
-			prescaler++;
-	}
+	/* calculate divider for maximum 1MHz PCLK */
+	prescaler = clk_freq / ONE_MHZ + 1;
 
 	value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET);
 
@@ -235,7 +225,7 @@ static int stm_thermal_calibration(struct stm_thermal_sensor *sensor)
 	value &= ~HSREF_CLK_DIV_MASK;
 
 	/* Set prescaler. pclk_freq/prescaler < 1MHz */
-	value |= (prescaler << HSREF_CLK_DIV_POS);
+	value |= (prescaler << HSREF_CLK_DIV_POS) & HSREF_CLK_DIV_MASK;
 
 	/* Select PCLK as reference clock */
 	value &= ~REFCLK_SEL;
@@ -289,28 +279,16 @@ static int stm_thermal_calculate_threshold(struct stm_thermal_sensor *sensor,
 					   int temp, u32 *th)
 {
 	int freqM;
-	u32 sampling_time;
-
-	/* Retrieve the number of periods to sample */
-	sampling_time = (readl_relaxed(sensor->base + DTS_CFGR1_OFFSET) &
-			TS1_SMP_TIME_MASK) >> TS1_SMP_TIME_POS;
 
 	/* Figure out the CLK_PTAT frequency for a given temperature */
-	freqM = ((temp - sensor->t0) * sensor->ramp_coeff)
-		 + sensor->fmt0;
-
-	dev_dbg(sensor->dev, "%s: freqM for threshold = %d Hz",
-		__func__, freqM);
+	freqM = ((temp - sensor->t0) * sensor->ramp_coeff) / 1000 +
+		sensor->fmt0;
 
 	/* Figure out the threshold sample number */
-	*th = clk_get_rate(sensor->clk);
+	*th = clk_get_rate(sensor->clk) * SAMPLING_TIME / freqM;
 	if (!*th)
 		return -EINVAL;
 
-	*th = *th / freqM;
-
-	*th *= sampling_time;
-
 	dev_dbg(sensor->dev, "freqM=%d Hz, threshold=0x%x", freqM, *th);
 
 	return 0;
@@ -320,42 +298,28 @@ static int stm_thermal_calculate_threshold(struct stm_thermal_sensor *sensor,
 static int stm_thermal_get_temp(void *data, int *temp)
 {
 	struct stm_thermal_sensor *sensor = data;
-	u32 sampling_time;
+	u32 periods;
 	int freqM, ret;
 
 	if (sensor->mode != THERMAL_DEVICE_ENABLED)
 		return -EAGAIN;
 
-	/* Retrieve the number of samples */
-	ret = readl_poll_timeout(sensor->base + DTS_DR_OFFSET, freqM,
-				 (freqM & TS1_MFREQ_MASK), STARTUP_TIME,
-				 POLL_TIMEOUT);
-
+	/* Retrieve the number of periods sampled */
+	ret = readl_relaxed_poll_timeout(sensor->base + DTS_DR_OFFSET, periods,
+					 (periods & TS1_MFREQ_MASK),
+					 STARTUP_TIME, POLL_TIMEOUT);
 	if (ret)
 		return ret;
 
-	if (!freqM)
-		return -ENODATA;
-
-	/* Retrieve the number of periods sampled */
-	sampling_time = (readl_relaxed(sensor->base + DTS_CFGR1_OFFSET) &
-			TS1_SMP_TIME_MASK) >> TS1_SMP_TIME_POS;
-
-	/* Figure out the number of samples per period */
-	freqM /= sampling_time;
-
 	/* Figure out the CLK_PTAT frequency */
-	freqM = clk_get_rate(sensor->clk) / freqM;
+	freqM = (clk_get_rate(sensor->clk) * SAMPLING_TIME) / periods;
 	if (!freqM)
 		return -EINVAL;
 
-	dev_dbg(sensor->dev, "%s: freqM=%d\n", __func__, freqM);
-
 	/* Figure out the temperature in mili celsius */
-	*temp = mcelsius(sensor->t0 + ((freqM - sensor->fmt0) /
-			 sensor->ramp_coeff));
+	*temp = (freqM - sensor->fmt0) * 1000 / sensor->ramp_coeff + sensor->t0;
 
-	dev_dbg(sensor->dev, "temperature = %d millicelsius", *temp);
+	dev_dbg(sensor->dev, "periods=0x%x t=%d mC", periods, *temp);
 
 	return 0;
 }
@@ -379,7 +343,8 @@ static int stm_thermal_set_trips(void *data, int low, int high)
 
 	if (low > -INT_MAX) {
 		sensor->low_en = 1;
-		ret = stm_thermal_calculate_threshold(sensor, low, &th);
+		/* add 0.5 of hysteresis due to measurement error */
+		ret = stm_thermal_calculate_threshold(sensor, low - 500, &th);
 		if (ret)
 			return ret;
 
-- 
2.17.1


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Re: [PATCH 2/4] thermal: stm32: fix IRQ flood on low threshold

[Daniel Lezcano]

Hi Pascal,

On 29/10/2019 17:45, Pascal Paillet wrote:
> Fix IRQ flood on low threshold by too ways:

Can you state the issue first ?

> - improve temperature reading resolution,
> - add an hysteresis to the low threshold: on low threshold interrupt,
> it is not possible to get the temperature value that has fired the
> interrupt. The time to acquire a new value is enough for the CPU to
> become hotter than the current low threshold.> Signed-off-by: Pascal Paillet <p.paillet@st.com>
> Change-Id: I3b63b8aab38fd651a165c4e69a2d090b3c6f5db3

Please remove the Change-Id tag.

Joe, Andy? checkpatch does not see the Change-Id, is it the expected
behavior?


[ ... ]

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Re: [PATCH 2/4] thermal: stm32: fix IRQ flood on low threshold

[Joe Perches]

On Tue, 2019-10-29 at 18:11 +0100, Daniel Lezcano wrote:
> On 29/10/2019 17:45, Pascal Paillet wrote:
> > Fix IRQ flood on low threshold by too ways:
> 
> Can you state the issue first ?
> 
> > - improve temperature reading resolution,
> > - add an hysteresis to the low threshold: on low threshold interrupt,
> > it is not possible to get the temperature value that has fired the
> > interrupt. The time to acquire a new value is enough for the CPU to
> > become hotter than the current low threshold.
[]
> > Signed-off-by: Pascal Paillet <p.paillet@st.com>
> > Change-Id: I3b63b8aab38fd651a165c4e69a2d090b3c6f5db3
> 
> Please remove the Change-Id tag.
> 
> Joe, Andy? checkpatch does not see the Change-Id, is it the expected
> behavior?

Yes.  It's after a sign-off so checkpatch doesn't care.




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Re: [PATCH 2/4] thermal: stm32: fix IRQ flood on low threshold

[Daniel Lezcano]

On 29/10/2019 18:15, Joe Perches wrote:
> On Tue, 2019-10-29 at 18:11 +0100, Daniel Lezcano wrote:
>> On 29/10/2019 17:45, Pascal Paillet wrote:
>>> Fix IRQ flood on low threshold by too ways:
>>
>> Can you state the issue first ?
>>
>>> - improve temperature reading resolution,
>>> - add an hysteresis to the low threshold: on low threshold interrupt,
>>> it is not possible to get the temperature value that has fired the
>>> interrupt. The time to acquire a new value is enough for the CPU to
>>> become hotter than the current low threshold.
> []
>>> Signed-off-by: Pascal Paillet <p.paillet@st.com>
>>> Change-Id: I3b63b8aab38fd651a165c4e69a2d090b3c6f5db3
>>
>> Please remove the Change-Id tag.
>>
>> Joe, Andy? checkpatch does not see the Change-Id, is it the expected
>> behavior?
> 
> Yes.  It's after a sign-off so checkpatch doesn't care.

Ah, I guess it is for Gerrit but we don't want those Change-Id in the
kernel history, right?

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Re: [PATCH 2/4] thermal: stm32: fix IRQ flood on low threshold

[Joe Perches]

On Tue, 2019-10-29 at 18:21 +0100, Daniel Lezcano wrote:
> On 29/10/2019 18:15, Joe Perches wrote:
> > On Tue, 2019-10-29 at 18:11 +0100, Daniel Lezcano wrote:
> > > On 29/10/2019 17:45, Pascal Paillet wrote:
> > > > Fix IRQ flood on low threshold by too ways:
> > > 
> > > Can you state the issue first ?
> > > 
> > > > - improve temperature reading resolution,
> > > > - add an hysteresis to the low threshold: on low threshold interrupt,
> > > > it is not possible to get the temperature value that has fired the
> > > > interrupt. The time to acquire a new value is enough for the CPU to
> > > > become hotter than the current low threshold.
> > []
> > > > Signed-off-by: Pascal Paillet <p.paillet@st.com>
> > > > Change-Id: I3b63b8aab38fd651a165c4e69a2d090b3c6f5db3
> > > 
> > > Please remove the Change-Id tag.
> > > 
> > > Joe, Andy? checkpatch does not see the Change-Id, is it the expected
> > > behavior?
> > 
> > Yes.  It's after a sign-off so checkpatch doesn't care.
> 
> Ah, I guess it is for Gerrit but we don't want those Change-Id in the
> kernel history, right?

So remove it from the patch.

checkpatch is not a perfect tool.
checkpatch will never be a perfect tool.
It's not possible for checkpatch to be a perfect tool.



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Re: [PATCH 2/4] thermal: stm32: fix IRQ flood on low threshold

[Daniel Lezcano]

On 29/10/2019 18:24, Joe Perches wrote:
> On Tue, 2019-10-29 at 18:21 +0100, Daniel Lezcano wrote:
>> On 29/10/2019 18:15, Joe Perches wrote:
>>> On Tue, 2019-10-29 at 18:11 +0100, Daniel Lezcano wrote:
>>>> On 29/10/2019 17:45, Pascal Paillet wrote:
>>>>> Fix IRQ flood on low threshold by too ways:
>>>>
>>>> Can you state the issue first ?
>>>>
>>>>> - improve temperature reading resolution,
>>>>> - add an hysteresis to the low threshold: on low threshold interrupt,
>>>>> it is not possible to get the temperature value that has fired the
>>>>> interrupt. The time to acquire a new value is enough for the CPU to
>>>>> become hotter than the current low threshold.
>>> []
>>>>> Signed-off-by: Pascal Paillet <p.paillet@st.com>
>>>>> Change-Id: I3b63b8aab38fd651a165c4e69a2d090b3c6f5db3
>>>>
>>>> Please remove the Change-Id tag.
>>>>
>>>> Joe, Andy? checkpatch does not see the Change-Id, is it the expected
>>>> behavior?
>>>
>>> Yes.  It's after a sign-off so checkpatch doesn't care.
>>
>> Ah, I guess it is for Gerrit but we don't want those Change-Id in the
>> kernel history, right?
> 
> So remove it from the patch.

It was not a sarcastic question. I just wanted to be sure the Change-Id
is something we always want to remove. There are some of them in the
kernel log and I got a doubt.

checkpatch is perfectly fine for me.

  -- Daniel


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[PATCH 3/4] thermal: stm32: fix engineering calibration value

[Pascal Paillet]

TS1_T0 is only used by engineering during calibration.
The temperature offset is actually fixed to 30 Celsius.

Signed-off-by: Pascal Paillet <p.paillet@st.com>
Change-Id: I83abea65ff3f58f8954256495f2d5d38f0d868d9
---
 drivers/thermal/st/stm_thermal.c | 22 ++++++----------------
 1 file changed, 6 insertions(+), 16 deletions(-)

diff --git a/drivers/thermal/st/stm_thermal.c b/drivers/thermal/st/stm_thermal.c
index 4bc1bbece0de..37abbdffe573 100644
--- a/drivers/thermal/st/stm_thermal.c
+++ b/drivers/thermal/st/stm_thermal.c
@@ -82,8 +82,7 @@
 #define ONE_MHZ			1000000
 #define POLL_TIMEOUT		5000
 #define STARTUP_TIME		40
-#define TS1_T0_VAL0		30000  /* 30 celsius */
-#define TS1_T0_VAL1		130000 /* 130 celsius */
+#define T0			30000  /* 30 celsius */
 #define NO_HW_TRIG		0
 #define SAMPLING_TIME		15
 
@@ -94,7 +93,7 @@ struct stm_thermal_sensor {
 	struct clk *clk;
 	int irq;
 	void __iomem *base;
-	int t0, fmt0, ramp_coeff;
+	int fmt0, ramp_coeff;
 	int low_en, high_en;
 };
 
@@ -248,14 +247,6 @@ static int stm_thermal_calibration(struct stm_thermal_sensor *sensor)
 /* Fill in DTS structure with factory sensor values */
 static int stm_thermal_read_factory_settings(struct stm_thermal_sensor *sensor)
 {
-	/* Retrieve engineering calibration temperature */
-	sensor->t0 = readl_relaxed(sensor->base + DTS_T0VALR1_OFFSET) &
-					TS1_T0_MASK;
-	if (!sensor->t0)
-		sensor->t0 = TS1_T0_VAL0;
-	else
-		sensor->t0 = TS1_T0_VAL1;
-
 	/* Retrieve fmt0 and put it on Hz */
 	sensor->fmt0 = ADJUST * (readl_relaxed(sensor->base +
 				 DTS_T0VALR1_OFFSET) & TS1_FMT0_MASK);
@@ -269,8 +260,8 @@ static int stm_thermal_read_factory_settings(struct stm_thermal_sensor *sensor)
 		return -EINVAL;
 	}
 
-	dev_dbg(sensor->dev, "%s: T0 = %doC, FMT0 = %dHz, RAMP_COEFF = %dHz/oC",
-		__func__, sensor->t0, sensor->fmt0, sensor->ramp_coeff);
+	dev_dbg(sensor->dev, "%s: FMT0 = %dHz, RAMP_COEFF = %dHz/oC",
+		__func__, sensor->fmt0, sensor->ramp_coeff);
 
 	return 0;
 }
@@ -281,8 +272,7 @@ static int stm_thermal_calculate_threshold(struct stm_thermal_sensor *sensor,
 	int freqM;
 
 	/* Figure out the CLK_PTAT frequency for a given temperature */
-	freqM = ((temp - sensor->t0) * sensor->ramp_coeff) / 1000 +
-		sensor->fmt0;
+	freqM = ((temp - T0) * sensor->ramp_coeff) / 1000 + sensor->fmt0;
 
 	/* Figure out the threshold sample number */
 	*th = clk_get_rate(sensor->clk) * SAMPLING_TIME / freqM;
@@ -317,7 +307,7 @@ static int stm_thermal_get_temp(void *data, int *temp)
 		return -EINVAL;
 
 	/* Figure out the temperature in mili celsius */
-	*temp = (freqM - sensor->fmt0) * 1000 / sensor->ramp_coeff + sensor->t0;
+	*temp = (freqM - sensor->fmt0) * 1000 / sensor->ramp_coeff + T0;
 
 	dev_dbg(sensor->dev, "periods=0x%x t=%d mC", periods, *temp);
 
-- 
2.17.1


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[PATCH 4/4] ARM: dts: stm32: remove thermal passive trip point on stm32mp157c

[Pascal Paillet]

Remove thermal passive trip point.

Signed-off-by: Pascal Paillet <p.paillet@st.com>
Change-Id: I494313cf467eea491236e73bd2fbe1803345586f
---
 arch/arm/boot/dts/stm32mp157c.dtsi | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/arch/arm/boot/dts/stm32mp157c.dtsi b/arch/arm/boot/dts/stm32mp157c.dtsi
index 9b11654a0a39..799b2aedd2c9 100644
--- a/arch/arm/boot/dts/stm32mp157c.dtsi
+++ b/arch/arm/boot/dts/stm32mp157c.dtsi
@@ -91,12 +91,6 @@
 			thermal-sensors = <&dts>;
 
 			trips {
-				cpu_alert1: cpu-alert1 {
-					temperature = <85000>;
-					hysteresis = <0>;
-					type = "passive";
-				};
-
 				cpu-crit {
 					temperature = <120000>;
 					hysteresis = <0>;
-- 
2.17.1


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Re: [PATCH 4/4] ARM: dts: stm32: remove thermal passive trip point on stm32mp157c

[Daniel Lezcano]

On 29/10/2019 17:45, Pascal Paillet wrote:
> Remove thermal passive trip point.

Why?

> Signed-off-by: Pascal Paillet <p.paillet@st.com>
> Change-Id: I494313cf467eea491236e73bd2fbe1803345586f

Remove Change-Id

> ---
>  arch/arm/boot/dts/stm32mp157c.dtsi | 6 ------
>  1 file changed, 6 deletions(-)
> 
> diff --git a/arch/arm/boot/dts/stm32mp157c.dtsi b/arch/arm/boot/dts/stm32mp157c.dtsi
> index 9b11654a0a39..799b2aedd2c9 100644
> --- a/arch/arm/boot/dts/stm32mp157c.dtsi
> +++ b/arch/arm/boot/dts/stm32mp157c.dtsi
> @@ -91,12 +91,6 @@
>  			thermal-sensors = <&dts>;
>  
>  			trips {
> -				cpu_alert1: cpu-alert1 {
> -					temperature = <85000>;
> -					hysteresis = <0>;
> -					type = "passive";
> -				};
> -
>  				cpu-crit {
>  					temperature = <120000>;
>  					hysteresis = <0>;
> 


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