Message-ID:
 <OSBPR01MB277527932C5570EBC3D877C7FFAC2@OSBPR01MB2775.jpnprd01.prod.outlook.com>
Date: Tue, 1 Apr 2025 12:05:40 +0000
From: John Madieu <john.madieu.xa@...renesas.com>
To: ALOK TIWARI <alok.a.tiwari@...cle.com>, "geert+renesas@...der.be"
	<geert+renesas@...der.be>, "conor+dt@...nel.org" <conor+dt@...nel.org>,
	"krzk+dt@...nel.org" <krzk+dt@...nel.org>, "robh@...nel.org"
	<robh@...nel.org>, "rafael@...nel.org" <rafael@...nel.org>,
	"daniel.lezcano@...aro.org" <daniel.lezcano@...aro.org>
CC: "magnus.damm@...il.com" <magnus.damm@...il.com>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	"john.madieu@...il.com" <john.madieu@...il.com>, "rui.zhang@...el.com"
	<rui.zhang@...el.com>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>, "linux-renesas-soc@...r.kernel.org"
	<linux-renesas-soc@...r.kernel.org>, "sboyd@...nel.org" <sboyd@...nel.org>,
	Biju Das <biju.das.jz@...renesas.com>, "linux-pm@...r.kernel.org"
	<linux-pm@...r.kernel.org>, "lukasz.luba@....com" <lukasz.luba@....com>
Subject: RE: Re : [PATCH v5 3/5] thermal: renesas: rzg3e: Add thermal driver
 for the Renesas RZ/G3E SoC

Hi Alok,

Thanks for your feedback.

> -----Original Message-----
> From: ALOK TIWARI <alok.a.tiwari@...cle.com>
> Sent: Monday, March 31, 2025 8:11 PM
> To: John Madieu <john.madieu.xa@...renesas.com>; geert+renesas@...der.be;
> conor+dt@...nel.org; krzk+dt@...nel.org; robh@...nel.org;
> rafael@...nel.org; daniel.lezcano@...aro.org
> Subject: Re : [PATCH v5 3/5] thermal: renesas: rzg3e: Add thermal driver
> for the Renesas RZ/G3E SoC
> 
> 
> 
> On 31-03-2025 03:19, 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@...renesas.com>
> > ---
> > v1 -> v2: fixes IRQ names
> > v2 -> v3: no changes
> > v3 -> v4: no changes
> > v5: removes curly braces arround single-line protected scoped guards
> >
> >   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
> > b9f7d2115b57..ba7c95146f01 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -20289,6 +20289,13 @@ 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@...renesas.com>
> > +L:	linux-pm@...r.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@...gutronix.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..fe50df057b74
> > --- /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 ADC interrupt */
> > +	writel(0, priv->base + TSU_SIER);
> what is difference b/w /* Disable all interrupts * / used in
> thermal_hw_enabl and Disable ADC interrupt ? The same comment can be used
> for better readability.

Noted. I got your point. Thanks.

> > +	/* 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;
> > +}
> > +
> always return 0 here ? what, if (!priv) return -EINVAL; ?

priv cannot be NULL here, guaranteed from probe().
Returning 0 here is expected by the thermal framework to notify
ops success.

> 
> > +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, };
> other renesas driver defined as rzg2l_tz_of_ops, can be used similar one
> rzg3e_tz_of_ops for consistency!

Thanks for pointing it out. Makes sense. Will double check and
update accordingly.

> > +
> > +static int rzg3e_thermal_probe(struct platform_device *pdev) {
> > +	struct device *dev = &pdev->dev;
> > +	struct rzg3e_thermal_priv *priv;
> > +	struct reset_control *rstc;
> 
> Thanks,
> Alok

Regards,
John

Powered by blists - more mailing lists