[PATCH 4/6] thermal: renesas: rzg3s: Add thermal driver for the Renesas RZ/G3S SoC

Claudiu
2025-01-03T16:38:38Z

From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

The Renesas RZ/G3S SoC features a Thermal Sensor Unit (TSU) that reports
the junction temperature. The temperature is reported through a dedicated
ADC channel. Add a driver for the Renesas RZ/G3S TSU.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---
MAINTAINERS | 7 +
drivers/thermal/renesas/Kconfig | 8 +
drivers/thermal/renesas/Makefile | 1 +
drivers/thermal/renesas/rzg3s_thermal.c | 301 ++++++++++++++++++++++++
4 files changed, 317 insertions(+)
create mode 100644 drivers/thermal/renesas/rzg3s_thermal.c

diff --git a/MAINTAINERS b/MAINTAINERS
index d2ab799a0659..0b5854dc2d5d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -20131,6 +20131,13 @@ S: Maintained
F: Documentation/devicetree/bindings/iio/potentiometer/renesas,x9250.yaml
F: drivers/iio/potentiometer/x9250.c

+RENESAS RZ/G3S THERMAL SENSOR UNIT DRIVER
+M: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
+L: linux-pm@vger.kernel.org
+S: Maintained
+F: Documentation/devicetree/bindings/thermal/renesas,r9a08g045-tsu.yaml
+F: drivers/thermal/renesas/rzg3s_thermal.c
+
RESET CONTROLLER FRAMEWORK
M: Philipp Zabel <p.zabel@pengutronix.de>
S: Maintained
diff --git a/drivers/thermal/renesas/Kconfig b/drivers/thermal/renesas/Kconfig
index dcf5fc5ae08e..566478797095 100644
--- a/drivers/thermal/renesas/Kconfig
+++ b/drivers/thermal/renesas/Kconfig
@@ -26,3 +26,11 @@ config RZG2L_THERMAL
help
Enable this to plug the RZ/G2L thermal sensor driver into the Linux
thermal framework.
+
+config RZG3S_THERMAL
+ tristate "Renesas RZ/G3S thermal driver"
+ depends on ARCH_R9A08G045 || COMPILE_TEST
+ depends on OF && IIO && RZG2L_ADC
+ help
+ Enable this to plug the RZ/G3S thermal sensor driver into the Linux
+ thermal framework.
diff --git a/drivers/thermal/renesas/Makefile b/drivers/thermal/renesas/Makefile
index bf9cb3cb94d6..1feb5ab78827 100644
--- a/drivers/thermal/renesas/Makefile
+++ b/drivers/thermal/renesas/Makefile
@@ -3,3 +3,4 @@
obj-$(CONFIG_RCAR_GEN3_THERMAL) += rcar_gen3_thermal.o
obj-$(CONFIG_RCAR_THERMAL) += rcar_thermal.o
obj-$(CONFIG_RZG2L_THERMAL) += rzg2l_thermal.o
+obj-$(CONFIG_RZG3S_THERMAL) += rzg3s_thermal.o
diff --git a/drivers/thermal/renesas/rzg3s_thermal.c b/drivers/thermal/renesas/rzg3s_thermal.c
new file mode 100644
index 000000000000..6719f9ca05eb
--- /dev/null
+++ b/drivers/thermal/renesas/rzg3s_thermal.c
@@ -0,0 +1,301 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Renesas RZ/G3S TSU Thermal Sensor Driver
+ *
+ * Copyright (C) 2024 Renesas Electronics Corporation
+ */
+
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/iio/consumer.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/thermal.h>
+#include <linux/units.h>
+
+#include "../thermal_hwmon.h"
+
+#define TSU_SM 0x0
+#define TSU_SM_EN BIT(0)
+#define TSU_SM_OE BIT(1)
+#define OTPTSUTRIM_REG(n) (0x18 + (n) * 0x4)
+#define OTPTSUTRIM_EN_MASK BIT(31)
+#define OTPTSUTRIM_MASK GENMASK(11, 0)
+
+#define TSU_READ_STEPS 8
+
+/* Default calibration values, if FUSE values are missing. */
+#define SW_CALIB0_VAL 1297
+#define SW_CALIB1_VAL 751
+
+#define MCELSIUS(temp) ((temp) * MILLIDEGREE_PER_DEGREE)
+
+/**
+ * struct rzg3s_thermal_priv - RZ/G3S thermal private data structure
+ * @base: TSU base address
+ * @dev: device pointer
+ * @tz: thermal zone pointer
+ * @rstc: reset control
+ * @channel: IIO channel to read the TSU
+ * @mode: current device mode
+ * @calib0: calibration value
+ * @calib1: calibration value
+ */
+struct rzg3s_thermal_priv {
+ void __iomem *base;
+ struct device *dev;
+ struct thermal_zone_device *tz;
+ struct reset_control *rstc;
+ struct iio_channel *channel;
+ enum thermal_device_mode mode;
+ u16 calib0;
+ u16 calib1;
+};
+
+static int rzg3s_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
+{
+ struct rzg3s_thermal_priv *priv = thermal_zone_device_priv(tz);
+ struct device *dev = priv->dev;
+ u32 ts_code_ave = 0;
+ int ret, val;
+
+ if (priv->mode != THERMAL_DEVICE_ENABLED)
+ return -EAGAIN;
+
+ ret = pm_runtime_resume_and_get(dev);
+ if (ret)
+ return ret;
+
+ for (u8 i = 0; i < TSU_READ_STEPS; i++) {
+ ret = iio_read_channel_raw(priv->channel, &val);
+ if (ret < 0)
+ goto rpm_put;
+
+ ts_code_ave += val;
+ /*
+ * According to the HW manual (section 40.4.4 Procedure for Measuring the
+ * Temperature) we need to wait here at leat 3us.
+ */
+ usleep_range(5, 10);
+ }
+
+ ret = 0;
+ ts_code_ave = DIV_ROUND_CLOSEST(ts_code_ave, TSU_READ_STEPS);
+
+ /*
+ * According to the HW manual (section 40.4.4 Procedure for Measuring the Temperature)
+ * the computation formula is as follows:
+ *
+ * Tj = (ts_code_ave - priv->calib1) * 165 / (priv->calib0 - priv->calib1) - 40
+ */
+ *temp = DIV_ROUND_CLOSEST((ts_code_ave - priv->calib1) * 165,
+ (priv->calib0 - priv->calib1)) - 40;
+
+ /* Report it in mili degrees Celsius and round it up to 0.5 degrees Celsius. */
+ *temp = roundup(MCELSIUS(*temp), 500);
+
+rpm_put:
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_autosuspend(dev);
+
+ return ret;
+}
+
+static void rzg3s_thermal_set_mode(struct rzg3s_thermal_priv *priv,
+ enum thermal_device_mode mode)
+{
+ struct device *dev = priv->dev;
+ int ret;
+
+ ret = pm_runtime_resume_and_get(dev);
+ if (ret)
+ return;
+
+ if (mode == THERMAL_DEVICE_DISABLED) {
+ writel(0, priv->base + TSU_SM);
+ } else {
+ writel(TSU_SM_EN, priv->base + TSU_SM);
+ /*
+ * According to the HW manual (section 40.4.1 Procedure for
+ * Starting the TSU) we need to wait here 30us or more.
+ */
+ usleep_range(30, 40);
+
+ writel(TSU_SM_OE | TSU_SM_EN, priv->base + TSU_SM);
+ /*
+ * According to the HW manual (section 40.4.1 Procedure for
+ * Starting the TSU) we need to wait here 50us or more.
+ */
+ usleep_range(50, 60);
+ }
+
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_autosuspend(dev);
+}
+
+static int rzg3s_thermal_change_mode(struct thermal_zone_device *tz,
+ enum thermal_device_mode mode)
+{
+ struct rzg3s_thermal_priv *priv = thermal_zone_device_priv(tz);
+
+ if (priv->mode == mode)
+ return 0;
+
+ rzg3s_thermal_set_mode(priv, mode);
+ priv->mode = mode;
+
+ return 0;
+}
+
+static const struct thermal_zone_device_ops rzg3s_tz_of_ops = {
+ .get_temp = rzg3s_thermal_get_temp,
+ .change_mode = rzg3s_thermal_change_mode,
+};
+
+static int rzg3s_thermal_read_calib(struct rzg3s_thermal_priv *priv)
+{
+ struct device *dev = priv->dev;
+ u32 val;
+ int ret;
+
+ ret = pm_runtime_resume_and_get(dev);
+ if (ret)
+ return ret;
+
+ val = readl(priv->base + OTPTSUTRIM_REG(0));
+ if (val & OTPTSUTRIM_EN_MASK)
+ priv->calib0 = FIELD_GET(OTPTSUTRIM_MASK, val);
+ else
+ priv->calib0 = SW_CALIB0_VAL;
+
+ val = readl(priv->base + OTPTSUTRIM_REG(1));
+ if (val & OTPTSUTRIM_EN_MASK)
+ priv->calib1 = FIELD_GET(OTPTSUTRIM_MASK, val);
+ else
+ priv->calib1 = SW_CALIB1_VAL;
+
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_autosuspend(dev);
+
+ return 0;
+}
+
+static int rzg3s_thermal_probe(struct platform_device *pdev)
+{
+ struct rzg3s_thermal_priv *priv;
+ struct device *dev = &pdev->dev;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(priv->base))
+ return PTR_ERR(priv->base);
+
+ priv->channel = devm_iio_channel_get(dev, "tsu");
+ if (IS_ERR(priv->channel))
+ return dev_err_probe(dev, PTR_ERR(priv->channel), "Failed to get IIO channel!\n");
+
+ priv->rstc = devm_reset_control_get_exclusive_deasserted(dev, NULL);
+ if (IS_ERR(priv->rstc))
+ return dev_err_probe(dev, PTR_ERR(priv->rstc), "Failed to get reset!\n");
+
+ priv->dev = dev;
+ priv->mode = THERMAL_DEVICE_DISABLED;
+ platform_set_drvdata(pdev, priv);
+
+ pm_runtime_set_autosuspend_delay(dev, 300);
+ pm_runtime_use_autosuspend(dev);
+ pm_runtime_enable(dev);
+
+ ret = rzg3s_thermal_read_calib(priv);
+ if (ret) {
+ dev_err_probe(dev, ret, "Failed to read calibration data!\n");
+ goto rpm_disable;
+ }
+
+ priv->tz = thermal_of_zone_register(dev->of_node, 0, priv, &rzg3s_tz_of_ops);
+ if (IS_ERR(priv->tz)) {
+ dev_err_probe(dev, PTR_ERR(priv->tz), "Failed to register thermal zone!\n");
+ goto rpm_disable;
+ }
+
+ ret = thermal_add_hwmon_sysfs(priv->tz);
+ if (ret) {
+ dev_err_probe(dev, ret, "Failed to add hwmon sysfs!\n");
+ goto tz_unregister;
+ }
+
+ return 0;
+
+tz_unregister:
+ thermal_of_zone_unregister(priv->tz);
+rpm_disable:
+ pm_runtime_disable(dev);
+ pm_runtime_dont_use_autosuspend(dev);
+ return ret;
+}
+
+static void rzg3s_thermal_remove(struct platform_device *pdev)
+{
+ struct rzg3s_thermal_priv *priv = dev_get_drvdata(&pdev->dev);
+
+ thermal_remove_hwmon_sysfs(priv->tz);
+ thermal_of_zone_unregister(priv->tz);
+ pm_runtime_disable(priv->dev);
+ pm_runtime_dont_use_autosuspend(priv->dev);
+}
+
+static int rzg3s_thermal_suspend(struct device *dev)
+{
+ struct rzg3s_thermal_priv *priv = dev_get_drvdata(dev);
+
+ rzg3s_thermal_set_mode(priv, THERMAL_DEVICE_DISABLED);
+
+ return reset_control_assert(priv->rstc);
+}
+
+static int rzg3s_thermal_resume(struct device *dev)
+{
+ struct rzg3s_thermal_priv *priv = dev_get_drvdata(dev);
+ int ret;
+
+ ret = reset_control_deassert(priv->rstc);
+ if (ret)
+ return ret;
+
+ if (priv->mode != THERMAL_DEVICE_DISABLED)
+ rzg3s_thermal_set_mode(priv, priv->mode);
+
+ return 0;
+}
+
+static const struct dev_pm_ops rzg3s_thermal_pm_ops = {
+ SYSTEM_SLEEP_PM_OPS(rzg3s_thermal_suspend, rzg3s_thermal_resume)
+};
+
+static const struct of_device_id rzg3s_thermal_dt_ids[] = {
+ { .compatible = "renesas,r9a08g045-tsu" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rzg3s_thermal_dt_ids);
+
+static struct platform_driver rzg3s_thermal_driver = {
+ .driver = {
+ .name = "rzg3s_thermal",
+ .of_match_table = rzg3s_thermal_dt_ids,
+ .pm = pm_ptr(&rzg3s_thermal_pm_ops),
+ },
+ .probe = rzg3s_thermal_probe,
+ .remove = rzg3s_thermal_remove,
+};
+module_platform_driver(rzg3s_thermal_driver);
+
+MODULE_DESCRIPTION("Renesas RZ/G3S Thermal Sensor Unit Driver");
+MODULE_AUTHOR("Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>");
+MODULE_LICENSE("GPL");
--
2.43.0