Hi Daniel,
Thanks for your review.
> -----Original Message-----
> From: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
> Sent: Wednesday, July 16, 2025 11:11 PM
> To: John Madieu <john.madieu.xa@xxxxxxxxxxxxxx>
> Subject: Re: [PATCH v6 3/5] thermal: renesas: rzg3e: Add thermal driver
> for the Renesas RZ/G3E SoC
>
> On Thu, May 22, 2025 at 08:22:46PM +0200, John Madieu wrote:
> > 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@xxxxxxxxxxxxxx>
> > ---
> >
> > Changes:
> >
> > v1 -> v2: fixes IRQ names
> > v2 -> v3: no changes
> > v3 -> v4: no changes
> > v5: removes curly braces arround single-line protected scoped guards
> > v6: Clarified comments in driver
> >
> > MAINTAINERS | 7 +
> > drivers/thermal/renesas/Kconfig | 7 +
> > drivers/thermal/renesas/Makefile | 1 +
> > drivers/thermal/renesas/rzg3e_thermal.c | 443
> > ++++++++++++++++++++++++
> > 4 files changed, 458 insertions(+)
> > create mode 100644 drivers/thermal/renesas/rzg3e_thermal.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS index
> > 79a8e2c73908..eb11494795e8 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -21161,6 +21161,13 @@ S: Maintained
> > F:
> Documentation/devicetree/bindings/iio/potentiometer/renesas,x9250.ya
> ml
> > F: drivers/iio/potentiometer/x9250.c
> >
> > +RENESAS RZ/G3E THERMAL SENSOR UNIT DRIVER
> > +M: John Madieu <john.madieu.xa@xxxxxxxxxxxxxx>
> > +L: linux-pm@xxxxxxxxxxxxxxx
> > +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@xxxxxxxxxxxxxx>
> > 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..348229da9ef4
> > --- /dev/null
> > +++ b/drivers/thermal/renesas/rzg3e_thermal.c
> > @@ -0,0 +1,443 @@
> > +// 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 all interrupts */
> > + 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;
>
> Why ?
>
As I kept internal reference to the device enablement state, I
thought it was necessary to check it here to ensure hardware
is not accessed inappropriately. After double checking I could see
that the thermal core already handles it.
Will remove in next version.
> > + reinit_completion(&priv->conv_complete);
> > +
> > + /* Enable ADC interrupt */
> > + writel(TSU_SIER_ADIE, priv->base + TSU_SIER);
>
> Why enable irq here ?
>
I did it this way because, in 'set_trips' callback, the
driver does trigger conversion to check whether the current
temperature is part of the window or not, and triggers the
comparison interrupt accordingly. Because of that, I did not
want the conversion-complete interrupt to also be triggered.
That's the reason why I enable conversion-complete interrupt
in 'get_temp', to make sure its interrupt is being triggered
only when the thermal core calls it.
Should I do it another way ?
> > + /* 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;
> > + }
>
> Can you explain what is happening here ?
>
I might not get what you are asking, but since I compute the
temperature in the hard IRQ handler, I just wait for it to complete
and notify the completion so I can grab the processed value to notify
the thermal core.
Please let me know if this does not answer your question.
> > + 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;
>
> That is not supposed to happen. set_trips is called from
> thermal_zone_device_update but the thermal zone is disabled, the function
> bails out, thus it should not call this callback.
>
Got it. I'll remove it in the next series.
> > + /* 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_of_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_of_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@xxxxxxxxxxxxxx>");
> > +MODULE_LICENSE("GPL");
> > --
> > 2.25.1
> >
>
> --
>
> <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
>
> Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
> <http://twitter.com/#!/linaroorg> Twitter |
> <http://www.linaro.org/linaro-blog/> Blog
Regards,
John
