[PATCH v2 0/2] add UniPhier thermal support

[PATCH v2 0/2] add UniPhier thermal support

[Kunihiko Hayashi]

This series adds support for CPU temperature monitor modules implemented
on UniPhier LD20 and PXs2 SoCs. This driver supports temperature monitoring
and alert function on the module.

Changes in v1:
- separate dts from this patchset as another patchset
- remove 'reg' description on the dt-bindings document
- fix the order of calling initialization functions
- replace mask bits to use GENMASK
- fix calculation of temperature because of not considering a negative value
- use devm_request_threaded_irq() instead of devm_request_irq() and
  separate a thread function from the interrupt handler
- add dependency to Kconfig
- set 120C to CRITICAL_TEMP_LIMIT as maximum temperature
- shrink each line of parameters to save the number of lines
- improve some comments and copyright description

Kunihiko Hayashi (2):
  dt-bindings: thermal: add binding documentation for UniPhier thermal
    monitor
  thermal: uniphier: add UniPhier thermal driver

 .../bindings/thermal/uniphier-thermal.txt          |  64 ++++
 drivers/thermal/Kconfig                            |   8 +
 drivers/thermal/Makefile                           |   1 +
 drivers/thermal/uniphier_thermal.c                 | 391 +++++++++++++++++++++
 4 files changed, 464 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/thermal/uniphier-thermal.txt
 create mode 100644 drivers/thermal/uniphier_thermal.c

-- 
2.7.4

[PATCH v2 1/2] dt-bindings: thermal: add binding documentation for UniPhier thermal monitor

[Kunihiko Hayashi]

Add devicetree binding documentation for thermal monitor implemented on
Socionext UniPhier SoCs.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Acked-by: Rob Herring <robh@kernel.org>
---
 .../bindings/thermal/uniphier-thermal.txt          | 64 ++++++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/thermal/uniphier-thermal.txt

diff --git a/Documentation/devicetree/bindings/thermal/uniphier-thermal.txt b/Documentation/devicetree/bindings/thermal/uniphier-thermal.txt
new file mode 100644
index 0000000..686c0b4
--- /dev/null
+++ b/Documentation/devicetree/bindings/thermal/uniphier-thermal.txt
@@ -0,0 +1,64 @@
+* UniPhier Thermal bindings
+
+This describes the devicetree bindings for thermal monitor supported by
+PVT(Process, Voltage and Temperature) monitoring unit implemented on Socionext
+UniPhier SoCs.
+
+Required properties:
+- compatible :
+  - "socionext,uniphier-pxs2-thermal" : For UniPhier PXs2 SoC
+  - "socionext,uniphier-ld20-thermal" : For UniPhier LD20 SoC
+- interrupts : IRQ for the temperature alarm
+- #thermal-sensor-cells : Should be 0. See ./thermal.txt for details.
+
+Optional properties:
+- socionext,tmod-calibration: A pair of calibrated values referred from PVT,
+                              in case that the values aren't set on SoC,
+                              like a reference board.
+
+Example:
+
+	sysctrl at 61840000 {
+		compatible = "socionext,uniphier-ld20-sysctrl",
+			     "simple-mfd", "syscon";
+		reg = <0x61840000 0x10000>;
+		...
+		pvtctl: pvtctl {
+			compatible = "socionext,uniphier-ld20-thermal";
+			interrupts = <0 3 1>;
+			#thermal-sensor-cells = <0>;
+		};
+		...
+	};
+
+	thermal-zones {
+		cpu_thermal {
+			polling-delay-passive = <250>;	/* 250ms */
+			polling-delay = <1000>;		/* 1000ms */
+			thermal-sensors = <&pvtctl>;
+
+			trips {
+				cpu_crit: cpu_crit {
+					temperature = <110000>;	/* 110C */
+					hysteresis = <2000>;
+					type = "critical";
+				};
+				cpu_alert: cpu_alert {
+					temperature = <100000>;	/* 100C */
+					hysteresis = <2000>;
+					type = "passive";
+				};
+			};
+
+			cooling-maps {
+				map0 {
+					trip = <&cpu_alert>;
+					cooling-device = <&cpu0 (-1) (-1)>;
+				};
+				map1 {
+					trip = <&cpu_alert>;
+					cooling-device = <&cpu2 (-1) (-1)>;
+				};
+			};
+		};
+	};
-- 
2.7.4

[PATCH v2 2/2] thermal: uniphier: add UniPhier thermal driver

[Kunihiko Hayashi]

Add a thermal driver for on-chip PVT (Process, Voltage and Temperature)
monitoring unit implemented on UniPhier SoCs. This driver supports
temperature monitoring and alert function.

Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
---
 drivers/thermal/Kconfig            |   8 +
 drivers/thermal/Makefile           |   1 +
 drivers/thermal/uniphier_thermal.c | 391 +++++++++++++++++++++++++++++++++++++
 3 files changed, 400 insertions(+)
 create mode 100644 drivers/thermal/uniphier_thermal.c

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 776b343..6631826 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -453,4 +453,12 @@ config ZX2967_THERMAL
 	  the primitive temperature sensor embedded in zx2967 SoCs.
 	  This sensor generates the real time die temperature.
 
+config UNIPHIER_THERMAL
+	tristate "Socionext UniPhier thermal driver"
+	depends on ARCH_UNIPHIER || COMPILE_TEST
+	depends on THERMAL_OF && MFD_SYSCON
+	help
+	  Enable this to plug in UniPhier on-chip PVT thermal driver into the
+	  thermal framework. The driver supports CPU thermal zone temperature
+	  reporting and a couple of trip points.
 endif
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 7adae20..05b6e7c 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -58,3 +58,4 @@ obj-$(CONFIG_HISI_THERMAL)     += hisi_thermal.o
 obj-$(CONFIG_MTK_THERMAL)	+= mtk_thermal.o
 obj-$(CONFIG_GENERIC_ADC_THERMAL)	+= thermal-generic-adc.o
 obj-$(CONFIG_ZX2967_THERMAL)	+= zx2967_thermal.o
+obj-$(CONFIG_UNIPHIER_THERMAL)	+= uniphier_thermal.o
diff --git a/drivers/thermal/uniphier_thermal.c b/drivers/thermal/uniphier_thermal.c
new file mode 100644
index 0000000..7664f58
--- /dev/null
+++ b/drivers/thermal/uniphier_thermal.c
@@ -0,0 +1,391 @@
+/**
+ * uniphier_thermal.c - Socionext UniPhier thermal driver
+ *
+ * Copyright 2014      Panasonic Corporation
+ * Copyright 2016-2017 Socionext Inc.
+ * All rights reserved.
+ *
+ * Author:
+ *	Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2  of
+ * the License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/bitops.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/thermal.h>
+
+#include "thermal_core.h"
+
+/*
+ * block registers
+ * addresses are the offset from .block_base
+ */
+#define PVTCTLEN			0x0000
+#define PVTCTLEN_EN			BIT(0)
+
+#define PVTCTLMODE			0x0004
+#define PVTCTLMODE_MASK			0xf
+#define PVTCTLMODE_TEMPMON		0x5
+
+#define EMONREPEAT			0x0040
+#define EMONREPEAT_ENDLESS		BIT(24)
+#define EMONREPEAT_PERIOD		GENMASK(3, 0)
+#define EMONREPEAT_PERIOD_1000000	0x9
+
+/*
+ * common registers
+ * addresses are the offset from .map_base
+ */
+#define PVTCTLSEL			0x0900
+#define PVTCTLSEL_MASK			GENMASK(2, 0)
+#define PVTCTLSEL_MONITOR		0
+
+#define SETALERT0			0x0910
+#define SETALERT1			0x0914
+#define SETALERT2			0x0918
+#define SETALERT_TEMP_OVF		(GENMASK(7, 0) << 16)
+#define SETALERT_TEMP_OVF_VALUE(val)	(((val) & GENMASK(7, 0)) << 16)
+#define SETALERT_EN			BIT(0)
+
+#define PMALERTINTCTL			0x0920
+#define PMALERTINTCTL_CLR(ch)		BIT(4 * (ch) + 2)
+#define PMALERTINTCTL_SET(ch)		BIT(4 * (ch) + 1)
+#define PMALERTINTCTL_EN(ch)		BIT(4 * (ch) + 0)
+#define PMALERTINTCTL_MASK		(GENMASK(10, 8) | GENMASK(6, 4) | \
+					 GENMASK(2, 0))
+
+#define TMOD				0x0928
+#define TMOD_MASK			GENMASK(9, 0)
+
+#define TMODCOEF			0x0e5c
+
+#define TMODSETUP0_EN			BIT(30)
+#define TMODSETUP0_VAL(val)		(((val) & GENMASK(13, 0)) << 16)
+#define TMODSETUP1_EN			BIT(15)
+#define TMODSETUP1_VAL(val)		((val) & GENMASK(14, 0))
+
+/* SoC critical temperature */
+#define CRITICAL_TEMP_LIMIT		(120 * 1000)
+
+/* Max # of alert channels */
+#define ALERT_CH_NUM			3
+
+/* SoC specific thermal sensor data */
+struct uniphier_tm_soc_data {
+	u32 map_base;
+	u32 block_base;
+	u32 tmod_setup_addr;
+};
+
+struct uniphier_tm_dev {
+	struct regmap *regmap;
+	bool alert_en[ALERT_CH_NUM];
+	u32 tmod_calib0;
+	u32 tmod_calib1;
+	struct thermal_zone_device *tz_dev;
+	const struct uniphier_tm_soc_data *data;
+};
+
+static int uniphier_tm_initialize_sensor(struct uniphier_tm_dev *tdev)
+{
+	struct regmap *map = tdev->regmap;
+	u32 val;
+	int ret;
+
+	/* stop PVT */
+	regmap_write_bits(map, tdev->data->block_base + PVTCTLEN,
+			  PVTCTLEN_EN, 0);
+
+	/*
+	 * set default value if missing calibrated value
+	 *
+	 * Since SoC has a calibrated value that was set in advance,
+	 * TMODCOEF shows non-zero and PVT refers the value internally.
+	 *
+	 * However, some boards don't have the calibrated value.
+	 * In that case, TMODCOEF shows zero and the driver has to set
+	 * default value manually.
+	 */
+	ret = regmap_read(map, tdev->data->map_base + TMODCOEF, &val);
+	if (ret)
+		return ret;
+	if (!val)
+		regmap_write(map, tdev->data->tmod_setup_addr,
+			    TMODSETUP0_EN | TMODSETUP0_VAL(tdev->tmod_calib0) |
+			    TMODSETUP1_EN | TMODSETUP1_VAL(tdev->tmod_calib1));
+
+	/* select temperature mode */
+	regmap_write_bits(map, tdev->data->block_base + PVTCTLMODE,
+			  PVTCTLMODE_MASK, PVTCTLMODE_TEMPMON);
+
+	/* set monitoring period */
+	regmap_write_bits(map, tdev->data->block_base + EMONREPEAT,
+			  EMONREPEAT_ENDLESS | EMONREPEAT_PERIOD,
+			  EMONREPEAT_ENDLESS | EMONREPEAT_PERIOD_1000000);
+
+	/* set monitor mode */
+	regmap_write_bits(map, tdev->data->map_base + PVTCTLSEL,
+			  PVTCTLSEL_MASK, PVTCTLSEL_MONITOR);
+
+	return 0;
+}
+
+static void uniphier_tm_set_alert(struct uniphier_tm_dev *tdev, u32 ch,
+				  u32 temp)
+{
+	struct regmap *map = tdev->regmap;
+
+	/* set alert temperature */
+	regmap_write_bits(map, tdev->data->map_base + SETALERT0 + (ch << 2),
+			  SETALERT_EN | SETALERT_TEMP_OVF,
+			  SETALERT_EN |
+			  SETALERT_TEMP_OVF_VALUE(temp / 1000));
+}
+
+static void uniphier_tm_enable_sensor(struct uniphier_tm_dev *tdev)
+{
+	struct regmap *map = tdev->regmap;
+	int i;
+	u32 bits = 0;
+
+	for (i = 0; i < ALERT_CH_NUM; i++)
+		if (tdev->alert_en[i])
+			bits |= PMALERTINTCTL_EN(i);
+
+	/* enable alert interrupt */
+	regmap_write_bits(map, tdev->data->map_base + PMALERTINTCTL,
+			  PMALERTINTCTL_MASK, bits);
+
+	/* start PVT */
+	regmap_write_bits(map, tdev->data->block_base + PVTCTLEN,
+			  PVTCTLEN_EN, PVTCTLEN_EN);
+}
+
+static void uniphier_tm_disable_sensor(struct uniphier_tm_dev *tdev)
+{
+	struct regmap *map = tdev->regmap;
+
+	/* disable alert interrupt */
+	regmap_write_bits(map, tdev->data->map_base + PMALERTINTCTL,
+			  PMALERTINTCTL_MASK, 0);
+
+	/* stop PVT */
+	regmap_write_bits(map, tdev->data->block_base + PVTCTLEN,
+			  PVTCTLEN_EN, 0);
+}
+
+static int uniphier_tm_get_temp(void *data, int *out_temp)
+{
+	struct uniphier_tm_dev *tdev = data;
+	struct regmap *map = tdev->regmap;
+	int ret;
+	u32 temp;
+
+	ret = regmap_read(map, tdev->data->map_base + TMOD, &temp);
+	if (ret)
+		return ret;
+
+	/*
+	 * Since MSB of TMOD_MASK in TMOD represents signed bit,
+	 * if the register value is bigger than or equal to
+	 * ((TMOD_MASK + 1) / 2), it represents a negative value
+	 * of temperature.
+	 */
+	temp &= TMOD_MASK;
+	if (temp >= ((TMOD_MASK + 1) / 2))
+		*out_temp = (temp - (TMOD_MASK + 1)) * 1000;
+	else
+		*out_temp = temp * 1000;	/* millicelsius */
+
+	return 0;
+}
+
+static const struct thermal_zone_of_device_ops uniphier_of_thermal_ops = {
+	.get_temp = uniphier_tm_get_temp,
+};
+
+static void uniphier_tm_irq_clear(struct uniphier_tm_dev *tdev)
+{
+	u32 mask = 0, bits = 0;
+	int i;
+
+	for (i = 0; i < ALERT_CH_NUM; i++) {
+		mask |= (PMALERTINTCTL_CLR(i) | PMALERTINTCTL_SET(i));
+		bits |= PMALERTINTCTL_CLR(i);
+	}
+
+	/* clear alert interrupt */
+	regmap_write_bits(tdev->regmap,
+			  tdev->data->map_base + PMALERTINTCTL, mask, bits);
+}
+
+static irqreturn_t uniphier_tm_alarm_irq(int irq, void *_tdev)
+{
+	struct uniphier_tm_dev *tdev = _tdev;
+
+	disable_irq_nosync(irq);
+	uniphier_tm_irq_clear(tdev);
+
+	return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t uniphier_tm_alarm_irq_thread(int irq, void *_tdev)
+{
+	struct uniphier_tm_dev *tdev = _tdev;
+
+	thermal_zone_device_update(tdev->tz_dev, THERMAL_EVENT_UNSPECIFIED);
+
+	return IRQ_HANDLED;
+}
+
+static int uniphier_tm_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct regmap *regmap;
+	struct device_node *parent;
+	struct uniphier_tm_dev *tdev;
+	const struct thermal_trip *trips;
+	const u32 *calib;
+	int i, ret, irq, ntrips, crit_temp = INT_MAX;
+
+	tdev = devm_kzalloc(dev, sizeof(*tdev), GFP_KERNEL);
+	if (!tdev)
+		return -ENOMEM;
+
+	tdev->data = of_device_get_match_data(dev);
+	if (WARN_ON(!tdev->data))
+		return -EINVAL;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	/* get tmod-calibration values */
+	calib = of_get_property(dev->of_node, "socionext,tmod-calibration",
+				NULL);
+	if (calib) {
+		tdev->tmod_calib0 = of_read_number(calib, 1);
+		tdev->tmod_calib1 = of_read_number(calib + 1, 1);
+	}
+
+	/* get regmap from syscon node */
+	parent = of_get_parent(dev->of_node); /* parent should be syscon node */
+	regmap = syscon_node_to_regmap(parent);
+	of_node_put(parent);
+	if (IS_ERR(regmap)) {
+		dev_err(dev, "failed to get regmap (error %ld)\n",
+			PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+	tdev->regmap = regmap;
+
+	ret = uniphier_tm_initialize_sensor(tdev);
+	if (ret) {
+		dev_err(dev, "failed to initialize sensor\n");
+		return ret;
+	}
+
+	ret = devm_request_threaded_irq(dev, irq, uniphier_tm_alarm_irq,
+					uniphier_tm_alarm_irq_thread,
+					0, "thermal", tdev);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, tdev);
+
+	tdev->tz_dev = devm_thermal_zone_of_sensor_register(dev, 0, tdev,
+						&uniphier_of_thermal_ops);
+	if (IS_ERR(tdev->tz_dev)) {
+		dev_err(dev, "failed to register sensor device\n");
+		return PTR_ERR(tdev->tz_dev);
+	}
+
+	/* get trip points */
+	trips = of_thermal_get_trip_points(tdev->tz_dev);
+	ntrips = of_thermal_get_ntrips(tdev->tz_dev);
+	if (ntrips > ALERT_CH_NUM) {
+		dev_err(dev, "thermal zone has too many trips\n");
+		return -E2BIG;
+	}
+
+	/* set alert temperatures */
+	for (i = 0; i < ntrips; i++) {
+		if (trips[i].type == THERMAL_TRIP_CRITICAL &&
+		    trips[i].temperature < crit_temp)
+			crit_temp = trips[i].temperature;
+		uniphier_tm_set_alert(tdev, i, trips[i].temperature);
+		tdev->alert_en[i] = true;
+	}
+	if (crit_temp > CRITICAL_TEMP_LIMIT) {
+		dev_err(dev, "critical trip is over limit(>%d), or not set\n",
+			CRITICAL_TEMP_LIMIT);
+		return -EINVAL;
+	}
+
+	uniphier_tm_enable_sensor(tdev);
+
+	return 0;
+}
+
+static int uniphier_tm_remove(struct platform_device *pdev)
+{
+	struct uniphier_tm_dev *tdev = platform_get_drvdata(pdev);
+
+	/* disable sensor */
+	uniphier_tm_disable_sensor(tdev);
+
+	return 0;
+}
+
+static const struct uniphier_tm_soc_data uniphier_pxs2_tm_data = {
+	.map_base        = 0xe000,
+	.block_base      = 0xe000,
+	.tmod_setup_addr = 0xe904,
+};
+
+static const struct uniphier_tm_soc_data uniphier_ld20_tm_data = {
+	.map_base        = 0xe000,
+	.block_base      = 0xe800,
+	.tmod_setup_addr = 0xe938,
+};
+
+static const struct of_device_id uniphier_tm_dt_ids[] = {
+	{
+		.compatible = "socionext,uniphier-pxs2-thermal",
+		.data       = &uniphier_pxs2_tm_data,
+	},
+	{
+		.compatible = "socionext,uniphier-ld20-thermal",
+		.data       = &uniphier_ld20_tm_data,
+	},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, uniphier_tm_dt_ids);
+
+static struct platform_driver uniphier_tm_driver = {
+	.probe = uniphier_tm_probe,
+	.remove = uniphier_tm_remove,
+	.driver = {
+		.name = "uniphier-thermal",
+		.of_match_table = uniphier_tm_dt_ids,
+	},
+};
+module_platform_driver(uniphier_tm_driver);
+
+MODULE_AUTHOR("Kunihiko Hayashi <hayashi.kunihiko@socionext.com>");
+MODULE_DESCRIPTION("UniPhier thermal driver");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4

[PATCH v2 2/2] thermal: uniphier: add UniPhier thermal driver

[Eduardo Valentin]

Hey,

On Wed, Jun 28, 2017 at 07:11:59PM +0900, Kunihiko Hayashi wrote:
> Add a thermal driver for on-chip PVT (Process, Voltage and Temperature)
> monitoring unit implemented on UniPhier SoCs. This driver supports
> temperature monitoring and alert function.
> 
> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
> ---
>  drivers/thermal/Kconfig            |   8 +
>  drivers/thermal/Makefile           |   1 +
>  drivers/thermal/uniphier_thermal.c | 391 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 400 insertions(+)
>  create mode 100644 drivers/thermal/uniphier_thermal.c
> 
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 776b343..6631826 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -453,4 +453,12 @@ config ZX2967_THERMAL
>  	  the primitive temperature sensor embedded in zx2967 SoCs.
>  	  This sensor generates the real time die temperature.
>  
> +config UNIPHIER_THERMAL
> +	tristate "Socionext UniPhier thermal driver"
> +	depends on ARCH_UNIPHIER || COMPILE_TEST
> +	depends on THERMAL_OF && MFD_SYSCON
> +	help
> +	  Enable this to plug in UniPhier on-chip PVT thermal driver into the
> +	  thermal framework. The driver supports CPU thermal zone temperature
> +	  reporting and a couple of trip points.
>  endif
> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> index 7adae20..05b6e7c 100644
> --- a/drivers/thermal/Makefile
> +++ b/drivers/thermal/Makefile
> @@ -58,3 +58,4 @@ obj-$(CONFIG_HISI_THERMAL)     += hisi_thermal.o
>  obj-$(CONFIG_MTK_THERMAL)	+= mtk_thermal.o
>  obj-$(CONFIG_GENERIC_ADC_THERMAL)	+= thermal-generic-adc.o
>  obj-$(CONFIG_ZX2967_THERMAL)	+= zx2967_thermal.o
> +obj-$(CONFIG_UNIPHIER_THERMAL)	+= uniphier_thermal.o
> diff --git a/drivers/thermal/uniphier_thermal.c b/drivers/thermal/uniphier_thermal.c
> new file mode 100644
> index 0000000..7664f58
> --- /dev/null
> +++ b/drivers/thermal/uniphier_thermal.c
> @@ -0,0 +1,391 @@
> +/**
> + * uniphier_thermal.c - Socionext UniPhier thermal driver
> + *
> + * Copyright 2014      Panasonic Corporation
> + * Copyright 2016-2017 Socionext Inc.
> + * All rights reserved.
> + *
> + * Author:
> + *	Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
> + *
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2  of
> + * the License as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/interrupt.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/thermal.h>
> +
> +#include "thermal_core.h"
> +
> +/*
> + * block registers
> + * addresses are the offset from .block_base
> + */
> +#define PVTCTLEN			0x0000
> +#define PVTCTLEN_EN			BIT(0)
> +
> +#define PVTCTLMODE			0x0004
> +#define PVTCTLMODE_MASK			0xf
> +#define PVTCTLMODE_TEMPMON		0x5
> +
> +#define EMONREPEAT			0x0040
> +#define EMONREPEAT_ENDLESS		BIT(24)
> +#define EMONREPEAT_PERIOD		GENMASK(3, 0)
> +#define EMONREPEAT_PERIOD_1000000	0x9
> +
> +/*
> + * common registers
> + * addresses are the offset from .map_base
> + */
> +#define PVTCTLSEL			0x0900
> +#define PVTCTLSEL_MASK			GENMASK(2, 0)
> +#define PVTCTLSEL_MONITOR		0
> +
> +#define SETALERT0			0x0910
> +#define SETALERT1			0x0914
> +#define SETALERT2			0x0918
> +#define SETALERT_TEMP_OVF		(GENMASK(7, 0) << 16)
> +#define SETALERT_TEMP_OVF_VALUE(val)	(((val) & GENMASK(7, 0)) << 16)
> +#define SETALERT_EN			BIT(0)
> +
> +#define PMALERTINTCTL			0x0920
> +#define PMALERTINTCTL_CLR(ch)		BIT(4 * (ch) + 2)
> +#define PMALERTINTCTL_SET(ch)		BIT(4 * (ch) + 1)
> +#define PMALERTINTCTL_EN(ch)		BIT(4 * (ch) + 0)
> +#define PMALERTINTCTL_MASK		(GENMASK(10, 8) | GENMASK(6, 4) | \
> +					 GENMASK(2, 0))
> +
> +#define TMOD				0x0928
> +#define TMOD_MASK			GENMASK(9, 0)
> +
> +#define TMODCOEF			0x0e5c
> +
> +#define TMODSETUP0_EN			BIT(30)
> +#define TMODSETUP0_VAL(val)		(((val) & GENMASK(13, 0)) << 16)
> +#define TMODSETUP1_EN			BIT(15)
> +#define TMODSETUP1_VAL(val)		((val) & GENMASK(14, 0))
> +
> +/* SoC critical temperature */
> +#define CRITICAL_TEMP_LIMIT		(120 * 1000)
> +
> +/* Max # of alert channels */
> +#define ALERT_CH_NUM			3
> +
> +/* SoC specific thermal sensor data */
> +struct uniphier_tm_soc_data {
> +	u32 map_base;
> +	u32 block_base;
> +	u32 tmod_setup_addr;
> +};
> +
> +struct uniphier_tm_dev {
> +	struct regmap *regmap;
> +	bool alert_en[ALERT_CH_NUM];
> +	u32 tmod_calib0;
> +	u32 tmod_calib1;
> +	struct thermal_zone_device *tz_dev;
> +	const struct uniphier_tm_soc_data *data;
> +};
> +
> +static int uniphier_tm_initialize_sensor(struct uniphier_tm_dev *tdev)
> +{
> +	struct regmap *map = tdev->regmap;
> +	u32 val;
> +	int ret;
> +
> +	/* stop PVT */
> +	regmap_write_bits(map, tdev->data->block_base + PVTCTLEN,
> +			  PVTCTLEN_EN, 0);
> +
> +	/*
> +	 * set default value if missing calibrated value
> +	 *
> +	 * Since SoC has a calibrated value that was set in advance,
> +	 * TMODCOEF shows non-zero and PVT refers the value internally.
> +	 *
> +	 * However, some boards don't have the calibrated value.
> +	 * In that case, TMODCOEF shows zero and the driver has to set
> +	 * default value manually.
> +	 */
> +	ret = regmap_read(map, tdev->data->map_base + TMODCOEF, &val);
> +	if (ret)
> +		return ret;
> +	if (!val)
> +		regmap_write(map, tdev->data->tmod_setup_addr,
> +			    TMODSETUP0_EN | TMODSETUP0_VAL(tdev->tmod_calib0) |
> +			    TMODSETUP1_EN | TMODSETUP1_VAL(tdev->tmod_calib1));
> +
> +	/* select temperature mode */
> +	regmap_write_bits(map, tdev->data->block_base + PVTCTLMODE,
> +			  PVTCTLMODE_MASK, PVTCTLMODE_TEMPMON);
> +
> +	/* set monitoring period */
> +	regmap_write_bits(map, tdev->data->block_base + EMONREPEAT,
> +			  EMONREPEAT_ENDLESS | EMONREPEAT_PERIOD,
> +			  EMONREPEAT_ENDLESS | EMONREPEAT_PERIOD_1000000);
> +
> +	/* set monitor mode */
> +	regmap_write_bits(map, tdev->data->map_base + PVTCTLSEL,
> +			  PVTCTLSEL_MASK, PVTCTLSEL_MONITOR);
> +
> +	return 0;
> +}
> +
> +static void uniphier_tm_set_alert(struct uniphier_tm_dev *tdev, u32 ch,
> +				  u32 temp)
> +{
> +	struct regmap *map = tdev->regmap;
> +
> +	/* set alert temperature */
> +	regmap_write_bits(map, tdev->data->map_base + SETALERT0 + (ch << 2),
> +			  SETALERT_EN | SETALERT_TEMP_OVF,
> +			  SETALERT_EN |
> +			  SETALERT_TEMP_OVF_VALUE(temp / 1000));
> +}
> +
> +static void uniphier_tm_enable_sensor(struct uniphier_tm_dev *tdev)
> +{
> +	struct regmap *map = tdev->regmap;
> +	int i;
> +	u32 bits = 0;
> +
> +	for (i = 0; i < ALERT_CH_NUM; i++)
> +		if (tdev->alert_en[i])
> +			bits |= PMALERTINTCTL_EN(i);
> +
> +	/* enable alert interrupt */
> +	regmap_write_bits(map, tdev->data->map_base + PMALERTINTCTL,
> +			  PMALERTINTCTL_MASK, bits);
> +
> +	/* start PVT */
> +	regmap_write_bits(map, tdev->data->block_base + PVTCTLEN,
> +			  PVTCTLEN_EN, PVTCTLEN_EN);

Do we need to wait some time after starting PVT and before reading the
first temperature?

> +}
> +
> +static void uniphier_tm_disable_sensor(struct uniphier_tm_dev *tdev)
> +{
> +	struct regmap *map = tdev->regmap;
> +
> +	/* disable alert interrupt */
> +	regmap_write_bits(map, tdev->data->map_base + PMALERTINTCTL,
> +			  PMALERTINTCTL_MASK, 0);
> +
> +	/* stop PVT */
> +	regmap_write_bits(map, tdev->data->block_base + PVTCTLEN,
> +			  PVTCTLEN_EN, 0);
> +}
> +
> +static int uniphier_tm_get_temp(void *data, int *out_temp)
> +{
> +	struct uniphier_tm_dev *tdev = data;
> +	struct regmap *map = tdev->regmap;
> +	int ret;
> +	u32 temp;
> +
> +	ret = regmap_read(map, tdev->data->map_base + TMOD, &temp);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * Since MSB of TMOD_MASK in TMOD represents signed bit,
> +	 * if the register value is bigger than or equal to
> +	 * ((TMOD_MASK + 1) / 2), it represents a negative value
> +	 * of temperature.
> +	 */
> +	temp &= TMOD_MASK;
> +	if (temp >= ((TMOD_MASK + 1) / 2))
> +		*out_temp = (temp - (TMOD_MASK + 1)) * 1000;

But, why do you mask negative values? Are you considering them invalid?
should this be reported? Why simply silently transforming into positive?

> +	else
> +		*out_temp = temp * 1000;	/* millicelsius */
> +
> +	return 0;
> +}
> +
> +static const struct thermal_zone_of_device_ops uniphier_of_thermal_ops = {
> +	.get_temp = uniphier_tm_get_temp,
> +};
> +
> +static void uniphier_tm_irq_clear(struct uniphier_tm_dev *tdev)
> +{
> +	u32 mask = 0, bits = 0;
> +	int i;
> +
> +	for (i = 0; i < ALERT_CH_NUM; i++) {
> +		mask |= (PMALERTINTCTL_CLR(i) | PMALERTINTCTL_SET(i));
> +		bits |= PMALERTINTCTL_CLR(i);
> +	}
> +
> +	/* clear alert interrupt */
> +	regmap_write_bits(tdev->regmap,
> +			  tdev->data->map_base + PMALERTINTCTL, mask, bits);
> +}
> +
> +static irqreturn_t uniphier_tm_alarm_irq(int irq, void *_tdev)
> +{
> +	struct uniphier_tm_dev *tdev = _tdev;
> +
> +	disable_irq_nosync(irq);
> +	uniphier_tm_irq_clear(tdev);
> +
> +	return IRQ_WAKE_THREAD;
> +}
> +
> +static irqreturn_t uniphier_tm_alarm_irq_thread(int irq, void *_tdev)
> +{
> +	struct uniphier_tm_dev *tdev = _tdev;
> +
> +	thermal_zone_device_update(tdev->tz_dev, THERMAL_EVENT_UNSPECIFIED);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int uniphier_tm_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct regmap *regmap;
> +	struct device_node *parent;
> +	struct uniphier_tm_dev *tdev;
> +	const struct thermal_trip *trips;
> +	const u32 *calib;
> +	int i, ret, irq, ntrips, crit_temp = INT_MAX;
> +
> +	tdev = devm_kzalloc(dev, sizeof(*tdev), GFP_KERNEL);
> +	if (!tdev)
> +		return -ENOMEM;
> +
> +	tdev->data = of_device_get_match_data(dev);
> +	if (WARN_ON(!tdev->data))
> +		return -EINVAL;
> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0)
> +		return irq;
> +
> +	/* get tmod-calibration values */
> +	calib = of_get_property(dev->of_node, "socionext,tmod-calibration",
> +				NULL);
> +	if (calib) {
> +		tdev->tmod_calib0 = of_read_number(calib, 1);
> +		tdev->tmod_calib1 = of_read_number(calib + 1, 1);
> +	}
> +
> +	/* get regmap from syscon node */
> +	parent = of_get_parent(dev->of_node); /* parent should be syscon node */
> +	regmap = syscon_node_to_regmap(parent);
> +	of_node_put(parent);
> +	if (IS_ERR(regmap)) {
> +		dev_err(dev, "failed to get regmap (error %ld)\n",
> +			PTR_ERR(regmap));
> +		return PTR_ERR(regmap);
> +	}
> +	tdev->regmap = regmap;
> +
> +	ret = uniphier_tm_initialize_sensor(tdev);
> +	if (ret) {
> +		dev_err(dev, "failed to initialize sensor\n");
> +		return ret;
> +	}
> +
> +	ret = devm_request_threaded_irq(dev, irq, uniphier_tm_alarm_irq,
> +					uniphier_tm_alarm_irq_thread,
> +					0, "thermal", tdev);
> +	if (ret)
> +		return ret;
> +
> +	platform_set_drvdata(pdev, tdev);
> +
> +	tdev->tz_dev = devm_thermal_zone_of_sensor_register(dev, 0, tdev,
> +						&uniphier_of_thermal_ops);
> +	if (IS_ERR(tdev->tz_dev)) {
> +		dev_err(dev, "failed to register sensor device\n");
> +		return PTR_ERR(tdev->tz_dev);
> +	}
> +
> +	/* get trip points */
> +	trips = of_thermal_get_trip_points(tdev->tz_dev);
> +	ntrips = of_thermal_get_ntrips(tdev->tz_dev);
> +	if (ntrips > ALERT_CH_NUM) {
> +		dev_err(dev, "thermal zone has too many trips\n");
> +		return -E2BIG;
> +	}
> +
> +	/* set alert temperatures */
> +	for (i = 0; i < ntrips; i++) {
> +		if (trips[i].type == THERMAL_TRIP_CRITICAL &&
> +		    trips[i].temperature < crit_temp)
> +			crit_temp = trips[i].temperature;
> +		uniphier_tm_set_alert(tdev, i, trips[i].temperature);
> +		tdev->alert_en[i] = true;
> +	}
> +	if (crit_temp > CRITICAL_TEMP_LIMIT) {
> +		dev_err(dev, "critical trip is over limit(>%d), or not set\n",
> +			CRITICAL_TEMP_LIMIT);
> +		return -EINVAL;
> +	}
> +
> +	uniphier_tm_enable_sensor(tdev);
> +
> +	return 0;
> +}
> +
> +static int uniphier_tm_remove(struct platform_device *pdev)
> +{
> +	struct uniphier_tm_dev *tdev = platform_get_drvdata(pdev);
> +
> +	/* disable sensor */
> +	uniphier_tm_disable_sensor(tdev);
> +
> +	return 0;
> +}
> +
> +static const struct uniphier_tm_soc_data uniphier_pxs2_tm_data = {
> +	.map_base        = 0xe000,
> +	.block_base      = 0xe000,
> +	.tmod_setup_addr = 0xe904,
> +};
> +
> +static const struct uniphier_tm_soc_data uniphier_ld20_tm_data = {
> +	.map_base        = 0xe000,
> +	.block_base      = 0xe800,
> +	.tmod_setup_addr = 0xe938,
> +};
> +
> +static const struct of_device_id uniphier_tm_dt_ids[] = {
> +	{
> +		.compatible = "socionext,uniphier-pxs2-thermal",
> +		.data       = &uniphier_pxs2_tm_data,
> +	},
> +	{
> +		.compatible = "socionext,uniphier-ld20-thermal",
> +		.data       = &uniphier_ld20_tm_data,
> +	},
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, uniphier_tm_dt_ids);
> +
> +static struct platform_driver uniphier_tm_driver = {
> +	.probe = uniphier_tm_probe,
> +	.remove = uniphier_tm_remove,
> +	.driver = {
> +		.name = "uniphier-thermal",
> +		.of_match_table = uniphier_tm_dt_ids,
> +	},
> +};
> +module_platform_driver(uniphier_tm_driver);
> +
> +MODULE_AUTHOR("Kunihiko Hayashi <hayashi.kunihiko@socionext.com>");
> +MODULE_DESCRIPTION("UniPhier thermal driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 2.7.4
> 

[PATCH v2 2/2] thermal: uniphier: add UniPhier thermal driver

[Kunihiko Hayashi]

Hi Eduardo,
Thank you for your comment.

On Fri, 30 Jun 2017 20:16:33 -0700 <edubezval@gmail.com> wrote:

> Hey,
> 
> On Wed, Jun 28, 2017 at 07:11:59PM +0900, Kunihiko Hayashi wrote:
> > Add a thermal driver for on-chip PVT (Process, Voltage and Temperature)
> > monitoring unit implemented on UniPhier SoCs. This driver supports
> > temperature monitoring and alert function.
> > 
> > Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
> > ---
> >  drivers/thermal/Kconfig            |   8 +
> >  drivers/thermal/Makefile           |   1 +
> >  drivers/thermal/uniphier_thermal.c | 391 +++++++++++++++++++++++++++++++++++++
> >  3 files changed, 400 insertions(+)
> >  create mode 100644 drivers/thermal/uniphier_thermal.c

(snip)

> > +static void uniphier_tm_enable_sensor(struct uniphier_tm_dev *tdev)
> > +{
> > +	struct regmap *map = tdev->regmap;
> > +	int i;
> > +	u32 bits = 0;
> > +
> > +	for (i = 0; i < ALERT_CH_NUM; i++)
> > +		if (tdev->alert_en[i])
> > +			bits |= PMALERTINTCTL_EN(i);
> > +
> > +	/* enable alert interrupt */
> > +	regmap_write_bits(map, tdev->data->map_base + PMALERTINTCTL,
> > +			  PMALERTINTCTL_MASK, bits);
> > +
> > +	/* start PVT */
> > +	regmap_write_bits(map, tdev->data->block_base + PVTCTLEN,
> > +			  PVTCTLEN_EN, PVTCTLEN_EN);
> 
> Do we need to wait some time after starting PVT and before reading the
> first temperature?

Thanks for your pointing out.

According to the spec sheet, we can read first temperature
with waiting 700us after starting PVT. And after disabling PVT,
we must wait 1ms until next access.

I'll add "nsleep" after accessing PVTCTLEN in
uniphier_tm_{enable,disable}_sensor().

> > +}
> > +
> > +static void uniphier_tm_disable_sensor(struct uniphier_tm_dev *tdev)
> > +{
> > +	struct regmap *map = tdev->regmap;
> > +
> > +	/* disable alert interrupt */
> > +	regmap_write_bits(map, tdev->data->map_base + PMALERTINTCTL,
> > +			  PMALERTINTCTL_MASK, 0);
> > +
> > +	/* stop PVT */
> > +	regmap_write_bits(map, tdev->data->block_base + PVTCTLEN,
> > +			  PVTCTLEN_EN, 0);
> > +}
> > +
> > +static int uniphier_tm_get_temp(void *data, int *out_temp)
> > +{
> > +	struct uniphier_tm_dev *tdev = data;
> > +	struct regmap *map = tdev->regmap;
> > +	int ret;
> > +	u32 temp;
> > +
> > +	ret = regmap_read(map, tdev->data->map_base + TMOD, &temp);
> > +	if (ret)
> > +		return ret;
> > +
> > +	/*
> > +	 * Since MSB of TMOD_MASK in TMOD represents signed bit,
> > +	 * if the register value is bigger than or equal to
> > +	 * ((TMOD_MASK + 1) / 2), it represents a negative value
> > +	 * of temperature.
> > +	 */
> > +	temp &= TMOD_MASK;
> > +	if (temp >= ((TMOD_MASK + 1) / 2))
> > +		*out_temp = (temp - (TMOD_MASK + 1)) * 1000;
> 
> But, why do you mask negative values? Are you considering them invalid?
> should this be reported? Why simply silently transforming into positive?

My explanation comment is insufficient.
The whole TMOD register doesn't represent temperature value.

TMOD[31:9] has always 0 as reserved bits.
TMOD[8:0] has 2's complement value of temperature (Celsius)
represented by 9bits.
For example, when we read 0x1ff from the TMOD, it means -1.

Then according to linux/bitops.h,
it can be replaced with "*out_temp = sign_extend32(temp, 9)" simply.

Best Regards,
Kunihiko Hayashi