[PATCH v2 4/7] thermal: renesas: rzg3e: Add thermal driver for the Renesas RZ/G3E SoC

John Madieu
2025-02-27T13:11:31Z

The RZ/G3E SoC integrates a Temperature Sensor Unit (TSU) block designed
to monitor the chip's junction temperature. This sensor is connected to
channel 1 of the APB port clock/reset and provides temperature measurements.

It also requires calibration values stored in the system controller registers
for accurate temperature measurement. Add a driver for the Renesas RZ/G3E TSU.

Signed-off-by: John Madieu <john.madieu.xa@bp.renesas.com>
---
v1 -> v2: fix IRQ names

MAINTAINERS | 7 +
drivers/thermal/renesas/Kconfig | 7 +
drivers/thermal/renesas/Makefile | 1 +
drivers/thermal/renesas/rzg3e_thermal.c | 445 ++++++++++++++++++++++++
4 files changed, 460 insertions(+)
create mode 100644 drivers/thermal/renesas/rzg3e_thermal.c

diff --git a/MAINTAINERS b/MAINTAINERS
index b9f7d2115b57..ba7c95146f01 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -20289,6 +20289,13 @@ S: Maintained
F: Documentation/devicetree/bindings/iio/potentiometer/renesas,x9250.yaml
F: drivers/iio/potentiometer/x9250.c

+RENESAS RZ/G3E THERMAL SENSOR UNIT DRIVER
+M: John Madieu <john.madieu.xa@bp.renesas.com>
+L: linux-pm@vger.kernel.org
+S: Maintained
+F: Documentation/devicetree/bindings/thermal/renesas,r9a09g047-tsu.yaml
+F: drivers/thermal/renesas/rzg3e_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..10cf90fc4bfa 100644
--- a/drivers/thermal/renesas/Kconfig
+++ b/drivers/thermal/renesas/Kconfig
@@ -26,3 +26,10 @@ config RZG2L_THERMAL
help
Enable this to plug the RZ/G2L thermal sensor driver into the Linux
thermal framework.
+
+config RZG3E_THERMAL
+ tristate "Renesas RZ/G3E thermal driver"
+ depends on ARCH_RENESAS || COMPILE_TEST
+ help
+ Enable this to plug the RZ/G3E thermal sensor driver into the Linux
+ thermal framework.
diff --git a/drivers/thermal/renesas/Makefile b/drivers/thermal/renesas/Makefile
index bf9cb3cb94d6..5a3eba0dedd0 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_RZG3E_THERMAL) += rzg3e_thermal.o
diff --git a/drivers/thermal/renesas/rzg3e_thermal.c b/drivers/thermal/renesas/rzg3e_thermal.c
new file mode 100644
index 000000000000..be9e1d118a67
--- /dev/null
+++ b/drivers/thermal/renesas/rzg3e_thermal.c
@@ -0,0 +1,445 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Renesas RZ/G3E TSU Temperature Sensor Unit
+ *
+ * Copyright (C) 2025 Renesas Electronics Corporation
+ */
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include <linux/thermal.h>
+#include <linux/units.h>
+
+#include "../thermal_hwmon.h"
+
+/* SYS Trimming register offsets macro */
+#define SYS_TSU_TRMVAL(x) (0x330 + (x) * 4)
+
+/* TSU Register offsets and bits */
+#define TSU_SSUSR 0x00
+#define TSU_SSUSR_EN_TS BIT(0)
+#define TSU_SSUSR_ADC_PD_TS BIT(1)
+#define TSU_SSUSR_SOC_TS_EN BIT(2)
+
+#define TSU_STRGR 0x04
+#define TSU_STRGR_ADST BIT(0)
+
+#define TSU_SOSR1 0x08
+#define TSU_SOSR1_ADCT_8 0x03
+#define TSU_SOSR1_OUTSEL_AVERAGE BIT(9)
+
+/* Sensor Code Read Register */
+#define TSU_SCRR 0x10
+#define TSU_SCRR_OUT12BIT_TS GENMASK(11, 0)
+
+/* Sensor Status Register */
+#define TSU_SSR 0x14
+#define TSU_SSR_CONV_RUNNING BIT(0)
+
+/* Compare Mode Setting Register */
+#define TSU_CMSR 0x18
+#define TSU_CMSR_CMPEN BIT(0)
+#define TSU_CMSR_CMPCOND BIT(1)
+
+/* Lower Limit Setting Register */
+#define TSU_LLSR 0x1C
+#define TSU_LLSR_LIM GENMASK(11, 0)
+
+/* Upper Limit Setting Register */
+#define TSU_ULSR 0x20
+#define TSU_ULSR_ULIM GENMASK(11, 0)
+
+/* Interrupt Status Register */
+#define TSU_SISR 0x30
+#define TSU_SISR_ADF BIT(0)
+#define TSU_SISR_CMPF BIT(1)
+
+/* Interrupt Enable Register */
+#define TSU_SIER 0x34
+#define TSU_SIER_ADIE BIT(0)
+#define TSU_SIER_CMPIE BIT(1)
+
+/* Interrupt Clear Register */
+#define TSU_SICR 0x38
+#define TSU_SICR_ADCLR BIT(0)
+#define TSU_SICR_CMPCLR BIT(1)
+
+/* Temperature calculation constants */
+#define TSU_D 41
+#define TSU_E 126
+#define TSU_TRMVAL_MASK GENMASK(11, 0)
+
+#define TSU_POLL_DELAY_US 50
+#define TSU_TIMEOUT_US 10000
+#define TSU_MIN_CLOCK_RATE 24000000
+
+/**
+ * struct rzg3e_thermal_priv - RZ/G3E thermal private data structure
+ * @base: TSU base address
+ * @dev: device pointer
+ * @syscon: regmap for calibration values
+ * @zone: thermal zone pointer
+ * @mode: current tzd mode
+ * @conv_complete: ADC conversion completion
+ * @reg_lock: protect shared register access
+ * @cached_temp: last computed temperature (milliCelsius)
+ * @trmval: trim (calibration) values
+ */
+struct rzg3e_thermal_priv {
+ void __iomem *base;
+ struct device *dev;
+ struct regmap *syscon;
+ struct thermal_zone_device *zone;
+ enum thermal_device_mode mode;
+ struct completion conv_complete;
+ spinlock_t reg_lock;
+ int cached_temp;
+ u32 trmval[2];
+};
+
+static void rzg3e_thermal_hw_disable(struct rzg3e_thermal_priv *priv)
+{
+ /* Disable all interrupts first */
+ writel(0, priv->base + TSU_SIER);
+ /* Clear any pending interrupts */
+ writel(TSU_SICR_ADCLR | TSU_SICR_CMPCLR, priv->base + TSU_SICR);
+ /* Put device in power down */
+ writel(TSU_SSUSR_ADC_PD_TS, priv->base + TSU_SSUSR);
+}
+
+static void rzg3e_thermal_hw_enable(struct rzg3e_thermal_priv *priv)
+{
+ /* First clear any pending status */
+ writel(TSU_SICR_ADCLR | TSU_SICR_CMPCLR, priv->base + TSU_SICR);
+ /* Disable all interrupts */
+ writel(0, priv->base + TSU_SIER);
+
+ /* Enable thermal sensor */
+ writel(TSU_SSUSR_SOC_TS_EN | TSU_SSUSR_EN_TS, priv->base + TSU_SSUSR);
+ /* Setup for averaging mode with 8 samples */
+ writel(TSU_SOSR1_OUTSEL_AVERAGE | TSU_SOSR1_ADCT_8, priv->base + TSU_SOSR1);
+}
+
+static irqreturn_t rzg3e_thermal_cmp_irq(int irq, void *dev_id)
+{
+ struct rzg3e_thermal_priv *priv = dev_id;
+ u32 status;
+
+ status = readl(priv->base + TSU_SISR);
+ if (!(status & TSU_SISR_CMPF))
+ return IRQ_NONE;
+
+ /* Clear the comparison interrupt flag */
+ writel(TSU_SICR_CMPCLR, priv->base + TSU_SICR);
+
+ return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t rzg3e_thermal_cmp_threaded_irq(int irq, void *dev_id)
+{
+ struct rzg3e_thermal_priv *priv = dev_id;
+
+ thermal_zone_device_update(priv->zone, THERMAL_EVENT_UNSPECIFIED);
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t rzg3e_thermal_adc_irq(int irq, void *dev_id)
+{
+ struct rzg3e_thermal_priv *priv = dev_id;
+ u32 status;
+ u32 result;
+
+ /* Check if this is our interrupt */
+ status = readl(priv->base + TSU_SISR);
+ if (!(status & TSU_SISR_ADF))
+ return IRQ_NONE;
+
+ /* Disable ADC interrupt */
+ writel(0, priv->base + TSU_SIER);
+ /* Clear conversion complete interrupt */
+ writel(TSU_SICR_ADCLR, priv->base + TSU_SICR);
+
+ /* Read ADC conversion result */
+ result = readl(priv->base + TSU_SCRR) & TSU_SCRR_OUT12BIT_TS;
+
+ /*
+ * Calculate temperature using compensation formula
+ * Section 7.11.7.8 (Temperature Compensation Calculation)
+ *
+ * T(°C) = ((e - d) / (c -b)) * (a - b) + d
+ *
+ * a = 12 bits temperature code read from the sensor
+ * b = SYS trmval[0]
+ * c = SYS trmval[1]
+ * d = -41
+ * e = 126
+ */
+ s64 temp_val = div_s64(((TSU_E + TSU_D) * (s64)(result - priv->trmval[0])),
+ priv->trmval[1] - priv->trmval[0]) - TSU_D;
+ int new_temp = temp_val * MILLIDEGREE_PER_DEGREE;
+
+ scoped_guard(spinlock_irqsave, &priv->reg_lock) {
+ priv->cached_temp = new_temp;
+ }
+
+ complete(&priv->conv_complete);
+
+ return IRQ_HANDLED;
+}
+
+static int rzg3e_thermal_get_temp(struct thermal_zone_device *zone, int *temp)
+{
+ struct rzg3e_thermal_priv *priv = thermal_zone_device_priv(zone);
+ u32 val;
+ int ret;
+
+ if (priv->mode == THERMAL_DEVICE_DISABLED)
+ return -EBUSY;
+
+ reinit_completion(&priv->conv_complete);
+
+ /* Enable ADC interrupt */
+ writel(TSU_SIER_ADIE, priv->base + TSU_SIER);
+
+ /* Verify no ongoing conversion */
+ ret = readl_poll_timeout_atomic(priv->base + TSU_SSR, val,
+ !(val & TSU_SSR_CONV_RUNNING),
+ TSU_POLL_DELAY_US, TSU_TIMEOUT_US);
+ if (ret) {
+ dev_err(priv->dev, "ADC conversion timed out\n");
+ return ret;
+ }
+
+ /* Start conversion */
+ writel(TSU_STRGR_ADST, priv->base + TSU_STRGR);
+
+ if (!wait_for_completion_timeout(&priv->conv_complete,
+ msecs_to_jiffies(100))) {
+ dev_err(priv->dev, "ADC conversion completion timeout\n");
+ return -ETIMEDOUT;
+ }
+
+ scoped_guard(spinlock_irqsave, &priv->reg_lock) {
+ *temp = priv->cached_temp;
+ }
+
+ return 0;
+}
+
+/* Convert temperature in milliCelsius to raw sensor code */
+static int rzg3e_temp_to_raw(struct rzg3e_thermal_priv *priv, int temp_mc)
+{
+ s64 raw = div_s64(((temp_mc / 1000) - TSU_D) *
+ (priv->trmval[1] - priv->trmval[0]),
+ (TSU_E - TSU_D));
+ return clamp_val(raw, 0, 0xFFF);
+}
+
+static int rzg3e_thermal_set_trips(struct thermal_zone_device *tz, int low, int high)
+{
+ struct rzg3e_thermal_priv *priv = thermal_zone_device_priv(tz);
+ int ret;
+ int val;
+
+ if (low >= high)
+ return -EINVAL;
+
+ if (priv->mode == THERMAL_DEVICE_DISABLED)
+ return -EBUSY;
+
+ /* Set up comparison interrupt */
+ writel(0, priv->base + TSU_SIER);
+ writel(TSU_SICR_ADCLR | TSU_SICR_CMPCLR, priv->base + TSU_SICR);
+
+ /* Set thresholds */
+ writel(rzg3e_temp_to_raw(priv, low), priv->base + TSU_LLSR);
+ writel(rzg3e_temp_to_raw(priv, high), priv->base + TSU_ULSR);
+
+ /* Configure comparison:
+ * - Enable comparison function (CMPEN = 1)
+ * - Set comparison condition (CMPCOND = 0 for out of range)
+ */
+ writel(TSU_CMSR_CMPEN, priv->base + TSU_CMSR);
+
+ /* Enable comparison irq */
+ writel(TSU_SIER_CMPIE, priv->base + TSU_SIER);
+
+ /* Verify no ongoing conversion */
+ ret = readl_poll_timeout_atomic(priv->base + TSU_SSR, val,
+ !(val & TSU_SSR_CONV_RUNNING),
+ TSU_POLL_DELAY_US, TSU_TIMEOUT_US);
+ if (ret) {
+ dev_err(priv->dev, "ADC conversion timed out\n");
+ return ret;
+ }
+
+ /* Start a conversion to trigger comparison */
+ writel(TSU_STRGR_ADST, priv->base + TSU_STRGR);
+
+ return 0;
+}
+
+static int rzg3e_thermal_get_trimming(struct rzg3e_thermal_priv *priv)
+{
+ int ret;
+
+ ret = regmap_read(priv->syscon, SYS_TSU_TRMVAL(0), &priv->trmval[0]);
+ if (ret)
+ return ret;
+
+ ret = regmap_read(priv->syscon, SYS_TSU_TRMVAL(1), &priv->trmval[1]);
+ if (ret)
+ return ret;
+
+ priv->trmval[0] &= TSU_TRMVAL_MASK;
+ priv->trmval[1] &= TSU_TRMVAL_MASK;
+
+ if (!priv->trmval[0] || !priv->trmval[1])
+ return dev_err_probe(priv->dev, -EINVAL, "invalid trimming values");
+
+ return 0;
+}
+
+static int rzg3e_thermal_change_mode(struct thermal_zone_device *tz,
+ enum thermal_device_mode mode)
+{
+ struct rzg3e_thermal_priv *priv = thermal_zone_device_priv(tz);
+
+ if (mode == THERMAL_DEVICE_DISABLED)
+ rzg3e_thermal_hw_disable(priv);
+ else
+ rzg3e_thermal_hw_enable(priv);
+
+ priv->mode = mode;
+ return 0;
+}
+
+static const struct thermal_zone_device_ops rzg3e_tz_ops = {
+ .get_temp = rzg3e_thermal_get_temp,
+ .set_trips = rzg3e_thermal_set_trips,
+ .change_mode = rzg3e_thermal_change_mode,
+};
+
+static int rzg3e_thermal_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct rzg3e_thermal_priv *priv;
+ struct reset_control *rstc;
+ char *adc_name, *cmp_name;
+ int adc_irq, cmp_irq;
+ struct clk *clk;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->dev = dev;
+
+ priv->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(priv->base))
+ return dev_err_probe(dev, PTR_ERR(priv->base),
+ "Failed to map I/O memory");
+
+ priv->syscon = syscon_regmap_lookup_by_phandle(dev->of_node,
+ "renesas,tsu-calibration-sys");
+ if (IS_ERR(priv->syscon))
+ return dev_err_probe(dev, PTR_ERR(priv->syscon),
+ "Failed to get calibration syscon");
+
+ adc_irq = platform_get_irq_byname(pdev, "adi");
+ if (adc_irq < 0)
+ return adc_irq;
+
+ cmp_irq = platform_get_irq_byname(pdev, "adcmpi");
+ if (cmp_irq < 0)
+ return cmp_irq;
+
+ rstc = devm_reset_control_get_exclusive_deasserted(dev, NULL);
+ if (IS_ERR(rstc))
+ return dev_err_probe(dev, PTR_ERR(rstc),
+ "Failed to acquire deasserted reset");
+
+ platform_set_drvdata(pdev, priv);
+
+ spin_lock_init(&priv->reg_lock);
+ init_completion(&priv->conv_complete);
+
+ clk = devm_clk_get_enabled(dev, NULL);
+ if (IS_ERR(clk))
+ return dev_err_probe(dev, PTR_ERR(clk),
+ "Failed to get and enable clock");
+
+ if (clk_get_rate(clk) < TSU_MIN_CLOCK_RATE)
+ return dev_err_probe(dev, -EINVAL,
+ "Clock rate too low (minimum %d Hz required)",
+ TSU_MIN_CLOCK_RATE);
+
+ ret = rzg3e_thermal_get_trimming(priv);
+ if (ret)
+ return ret;
+
+ adc_name = devm_kasprintf(dev, GFP_KERNEL, "%s-adc", dev_name(dev));
+ if (!adc_name)
+ return -ENOMEM;
+
+ cmp_name = devm_kasprintf(dev, GFP_KERNEL, "%s-cmp", dev_name(dev));
+ if (!cmp_name)
+ return -ENOMEM;
+
+ /* Unit in a known disabled mode */
+ rzg3e_thermal_hw_disable(priv);
+
+ ret = devm_request_irq(dev, adc_irq, rzg3e_thermal_adc_irq,
+ IRQF_TRIGGER_RISING, adc_name, priv);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to request ADC IRQ");
+
+ ret = devm_request_threaded_irq(dev, cmp_irq, rzg3e_thermal_cmp_irq,
+ rzg3e_thermal_cmp_threaded_irq,
+ IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
+ cmp_name, priv);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to request comparison IRQ");
+
+ /* Register Thermal Zone */
+ priv->zone = devm_thermal_of_zone_register(dev, 0, priv, &rzg3e_tz_ops);
+ if (IS_ERR(priv->zone))
+ return dev_err_probe(dev, PTR_ERR(priv->zone),
+ "Failed to register thermal zone");
+
+ ret = devm_thermal_add_hwmon_sysfs(dev, priv->zone);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to add hwmon sysfs");
+
+ return 0;
+}
+
+static const struct of_device_id rzg3e_thermal_dt_ids[] = {
+ { .compatible = "renesas,r9a09g047-tsu" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rzg3e_thermal_dt_ids);
+
+static struct platform_driver rzg3e_thermal_driver = {
+ .driver = {
+ .name = "rzg3e_thermal",
+ .of_match_table = rzg3e_thermal_dt_ids,
+ },
+ .probe = rzg3e_thermal_probe,
+};
+module_platform_driver(rzg3e_thermal_driver);
+
+MODULE_DESCRIPTION("Renesas RZ/G3E TSU Thermal Sensor Driver");
+MODULE_AUTHOR("John Madieu <john.madieu.xa@bp.renesas.com>");
+MODULE_LICENSE("GPL");
--
2.25.1