thermal: uniphier: add UniPhier thermal driver

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>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

3 files changed, 393 insertions, 0 deletions

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index b5b5facb8747..b9f23653e0ea 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -473,4 +473,12 @@ 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 094d7039981c..8b79bca23536 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -59,3 +59,4 @@ 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 000000000000..95704732f760
--- /dev/null
+++ b/drivers/thermal/uniphier_thermal.c
@@ -0,0 +1,384 @@
+/**
+ * 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_WIDTH                      9
+
+#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;
+        struct device *dev;
+        bool alert_en[ALERT_CH_NUM];
+        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;
+        u32 tmod_calib[2];
+        int ret;
+
+        /* stop PVT */
+        regmap_write_bits(map, tdev->data->block_base + PVTCTLEN,
+                          PVTCTLEN_EN, 0);
+
+        /*
+         * Since SoC has a calibrated value that was set in advance,
+         * TMODCOEF shows non-zero and PVT refers the value internally.
+         *
+         * If TMODCOEF shows zero, the boards don't have the calibrated
+         * value, and the driver has to set default value from DT.
+         */
+        ret = regmap_read(map, tdev->data->map_base + TMODCOEF, &val);
+        if (ret)
+                return ret;
+        if (!val) {
+                /* look for the default values in DT */
+                ret = of_property_read_u32_array(tdev->dev->of_node,
+                                                 "socionext,tmod-calibration",
+                                                 tmod_calib,
+                                                 ARRAY_SIZE(tmod_calib));
+                if (ret)
+                        return ret;
+
+                regmap_write(map, tdev->data->tmod_setup_addr,
+                        TMODSETUP0_EN | TMODSETUP0_VAL(tmod_calib[0]) |
+                        TMODSETUP1_EN | TMODSETUP1_VAL(tmod_calib[1]));
+        }
+
+        /* 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);
+
+        usleep_range(700, 1500);        /* The spec note says at least 700us */
+}
+
+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);
+
+        usleep_range(1000, 2000);       /* The spec note says at least 1ms */
+}
+
+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;
+
+        /* MSB of the TMOD field is a sign bit */
+        *out_temp = sign_extend32(temp, TMOD_WIDTH - 1) * 1000;
+
+        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;
+        int i, ret, irq, ntrips, crit_temp = INT_MAX;
+
+        tdev = devm_kzalloc(dev, sizeof(*tdev), GFP_KERNEL);
+        if (!tdev)
+                return -ENOMEM;
+        tdev->dev = dev;
+
+        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 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");