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

[Kunihiko Hayashi <hayashi.kunihiko@socionext.com>]

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