Hi Niklas,
Thanks for the feedback.
> Subject: Re: [PATCH 3/5] thermal/drivers: Add TSU driver for RZ/G2L
>
> HI Biju,
>
> Thanks for your work.
>
> On 2021-11-16 15:17:48 +0000, Biju Das wrote:
> > Add Thermal Sensor Unit(TSU) driver for RZ/G2L SoC.
> >
> > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> > ---
> > drivers/thermal/Kconfig | 9 ++
> > drivers/thermal/Makefile | 1 +
> > drivers/thermal/rzg2l_thermal.c | 239
> > ++++++++++++++++++++++++++++++++
> > 3 files changed, 249 insertions(+)
> > create mode 100644 drivers/thermal/rzg2l_thermal.c
> >
> > diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig index
> > d7f44deab5b1..e37691e0bf20 100644
> > --- a/drivers/thermal/Kconfig
> > +++ b/drivers/thermal/Kconfig
> > @@ -354,6 +354,15 @@ config RCAR_GEN3_THERMAL
> > Enable this to plug the R-Car Gen3 or RZ/G2 thermal sensor driver
> into
> > the Linux thermal framework.
> >
> > +config RZG2L_THERMAL
> > + tristate "Renesas RZ/G2L thermal driver"
> > + depends on ARCH_RENESAS || COMPILE_TEST
> > + depends on HAS_IOMEM
> > + depends on OF
> > + help
> > + Enable this to plug the RZ/G2L thermal sensor driver into the
> Linux
> > + thermal framework.
> > +
> > config KIRKWOOD_THERMAL
> > tristate "Temperature sensor on Marvell Kirkwood SoCs"
> > depends on MACH_KIRKWOOD || COMPILE_TEST diff --git
> > a/drivers/thermal/Makefile b/drivers/thermal/Makefile index
> > 82fc3e616e54..f0c36a1530d5 100644
> > --- a/drivers/thermal/Makefile
> > +++ b/drivers/thermal/Makefile
> > @@ -37,6 +37,7 @@ obj-$(CONFIG_SUN8I_THERMAL) += sun8i_thermal.o
> > obj-$(CONFIG_ROCKCHIP_THERMAL) += rockchip_thermal.o
> > obj-$(CONFIG_RCAR_THERMAL) += rcar_thermal.o
> > obj-$(CONFIG_RCAR_GEN3_THERMAL) += rcar_gen3_thermal.o
> > +obj-$(CONFIG_RZG2L_THERMAL) += rzg2l_thermal.o
> > obj-$(CONFIG_KIRKWOOD_THERMAL) += kirkwood_thermal.o
> > obj-y += samsung/
> > obj-$(CONFIG_DOVE_THERMAL) += dove_thermal.o
> > diff --git a/drivers/thermal/rzg2l_thermal.c
> > b/drivers/thermal/rzg2l_thermal.c new file mode 100644 index
> > 000000000000..e551355cd4f6
> > --- /dev/null
> > +++ b/drivers/thermal/rzg2l_thermal.c
> > @@ -0,0 +1,239 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Renesas RZ/G2L TSU Thermal Sensor Driver
> > + *
> > + * Copyright (C) 2021 Renesas Electronics Corporation */ #include
> > +<linux/delay.h> #include <linux/err.h> #include <linux/io.h> #include
> > +<linux/iopoll.h> #include <linux/module.h> #include
> > +<linux/of_device.h> #include <linux/platform_device.h> #include
> > +<linux/pm_runtime.h> #include <linux/reset.h> #include
> > +<linux/thermal.h>
> > +
> > +#include "thermal_hwmon.h"
> > +
> > +#define CTEMP_MASK 0xFFF
> > +
> > +/* default calibration values, if FUSE values are missing */
> > +#define SW_CALIB0_VAL 3148
> > +#define SW_CALIB1_VAL 503
> > +
> > +/* Register offsets */
> > +#define TSU_SM 0x00
> > +#define TSU_ST 0x04
> > +#define TSU_SAD 0x0C
> > +#define TSU_SS 0x10
> > +
> > +#define OTPTSUTRIM_REG(n) (0x18 + ((n) * 0x4))
> > +
> > +/* Sensor Mode Register(TSU_SM) */
> > +#define TSU_SM_EN_TS BIT(0)
> > +#define TSU_SM_ADC_EN_TS BIT(1)
> > +#define TSU_SM_NORMAL_MODE (TSU_SM_EN_TS | TSU_SM_ADC_EN_TS)
> > +
> > +/* TSU_ST bits */
> > +#define TSU_ST_START BIT(0)
> > +
> > +#define TSU_SS_CONV_RUNNING BIT(0)
> > +
> > +#define TS_CODE_AVE_SCALE(x) ((x) * 1000000)
> > +#define MCELSIUS(temp) ((temp) * 1000)
> > +#define TS_CODE_CAP_TIMES 8 /* Capture times */
> > +#define RZG2L_THERMAL_GRAN 500 /* milli Celsius */
> > +
> > +#define RZG2L_TSU_SS_TIMEOUT_US 1000
> > +
> > +struct rzg2l_thermal_priv {
> > + struct device *dev;
> > + void __iomem *base;
> > + struct thermal_zone_device *zone;
> > + struct reset_control *rstc;
> > + u32 calib0, calib1;
> > +};
> > +
> > +static inline u32 rzg2l_thermal_read(struct rzg2l_thermal_priv *priv,
> > +u32 reg) {
> > + return ioread32(priv->base + reg);
> > +}
> > +
> > +static inline void rzg2l_thermal_write(struct rzg2l_thermal_priv *priv,
> u32 reg,
> > + u32 data)
> > +{
> > + iowrite32(data, priv->base + reg);
> > +}
> > +
> > +static int rzg2l_thermal_round(int temp) {
> > + int result, round_offs;
> > +
> > + round_offs = temp >= 0 ? RZG2L_THERMAL_GRAN / 2 : -
> RZG2L_THERMAL_GRAN / 2;
> > + result = (temp + round_offs) / RZG2L_THERMAL_GRAN;
> > +
> > + return result * RZG2L_THERMAL_GRAN;
> > +}
> > +
> > +static int rzg2l_thermal_get_temp(void *devdata, int *temp) {
> > + struct rzg2l_thermal_priv *priv = devdata;
> > + u32 result, dsensor, ts_code_ave;
> > + int val, i;
> > +
> > + result = 0;
> > + /* Read the ADC value 8 times with an interval of 20 microsecs */
> > + for (i = 0; i < TS_CODE_CAP_TIMES ; i++) {
> > + result += rzg2l_thermal_read(priv, TSU_SAD) & CTEMP_MASK;
> > + usleep_range(20, 30);
> > + }
> > +
> > + /* Calculate the average value */
> > + ts_code_ave = result / TS_CODE_CAP_TIMES;
> > +
> > + /* Curvature correction */
> > + dsensor = TS_CODE_AVE_SCALE(ts_code_ave) /
> > + (TS_CODE_AVE_SCALE(1) + (ts_code_ave * 13));
> > +
> > + /* Temperature calculation */
> > + val = ((dsensor - priv->calib1) * (MCELSIUS(165) /
> > + (priv->calib0 - priv->calib1))) - MCELSIUS(40);
> > +
> > + /* Round value to device granularity setting */
> > + *temp = rzg2l_thermal_round(val);
> > +
> > + return 0;
> > +}
> > +
> > +static const struct thermal_zone_of_device_ops rzg2l_tz_of_ops = {
> > + .get_temp = rzg2l_thermal_get_temp,
> > +};
> > +
> > +static int rzg2l_thermal_init(struct rzg2l_thermal_priv *priv) {
> > + u32 reg_val;
> > +
> > + rzg2l_thermal_write(priv, TSU_SM, TSU_SM_NORMAL_MODE);
> > + rzg2l_thermal_write(priv, TSU_ST, 0);
> > +
> > + /* Before setting START bit, Wait for 60 µs */
> > + usleep_range(60, 80);
> > +
> > + reg_val = rzg2l_thermal_read(priv, TSU_ST);
> > + reg_val |= TSU_ST_START;
> > + rzg2l_thermal_write(priv, TSU_ST, reg_val);
> > +
> > + return readl_poll_timeout(priv->base + TSU_SS, reg_val,
> > + reg_val == TSU_SS_CONV_RUNNING, 50,
> > + RZG2L_TSU_SS_TIMEOUT_US);
> > +}
> > +
> > +static int rzg2l_thermal_remove(struct platform_device *pdev) {
> > + struct rzg2l_thermal_priv *priv = dev_get_drvdata(&pdev->dev);
> > +
> > + pm_runtime_put(&pdev->dev);
> > + pm_runtime_disable(&pdev->dev);
> > + reset_control_assert(priv->rstc);
> > +
> > + return 0;
> > +}
> > +
> > +static void rzg2l_hwmon_action(void *data) {
> > + struct thermal_zone_device *zone = data;
> > +
> > + thermal_remove_hwmon_sysfs(zone);
> > +}
> > +
> > +static int rzg2l_thermal_probe(struct platform_device *pdev) {
> > + struct thermal_zone_device *zone;
> > + struct rzg2l_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->dev = dev;
> > + priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
> > + if (IS_ERR(priv->rstc))
> > + return dev_err_probe(dev, PTR_ERR(priv->rstc),
> > + "failed to get cpg reset");
> > +
> > + reset_control_deassert(priv->rstc);
> > +
> > + pm_runtime_enable(dev);
> > + pm_runtime_get_sync(dev);
> > +
> > + priv->calib0 = rzg2l_thermal_read(priv, OTPTSUTRIM_REG(0));
> > + if (!priv->calib0)
> > + priv->calib0 = SW_CALIB0_VAL;
> > +
> > + priv->calib1 = rzg2l_thermal_read(priv, OTPTSUTRIM_REG(1));
> > + if (!priv->calib1)
> > + priv->calib1 = SW_CALIB1_VAL;
> > +
> > + platform_set_drvdata(pdev, priv);
> > + ret = rzg2l_thermal_init(priv);
> > + if (ret) {
> > + dev_err(dev, "Failed to start TSU");
> > + goto error_unregister;
> > + }
> > +
> > + zone = devm_thermal_zone_of_sensor_register(dev, 0, priv,
> > + &rzg2l_tz_of_ops);
> > + if (IS_ERR(zone)) {
> > + dev_err(dev, "Can't register thermal zone");
> > + ret = PTR_ERR(zone);
> > + goto error_unregister;
> > + }
> > +
> > + priv->zone = zone;
> > + priv->zone->tzp->no_hwmon = false;
> > + ret = thermal_add_hwmon_sysfs(priv->zone);
> > + if (ret)
> > + goto error_unregister;
> > +
> > + ret = devm_add_action_or_reset(dev, rzg2l_hwmon_action, zone);
> > + if (ret)
> > + goto error_unregister;
>
> This driver only uses one zone would it be worth considering calling
> thermal_remove_hwmon_sysfs() directly from rzg2l_thermal_remove()?
> Compare then Renesas Gen2 and Gen3 drivers. Where Gen3 uses devres to make
> it easier to deal with more then one zone wile Gen2 calls it directly from
> its remove function.
OK, will use Gen2 style as it has 1 sensor on the next version.
Another separate question, I have in my mind is how do we test trip points
for negative temperature?
This TSU doesn't have any interrupts and
we need to use polling, The range is -40 to 125 degrees.
If it goes below -40, I guess we need to shutdown the system.
On device tree we normally specify only positive temperature.
How do we handle this?
Regards,
Biju
>
> > +
> > + dev_info(dev, "TSU probed with %s caliberation values",
> > + rzg2l_thermal_read(priv, OTPTSUTRIM_REG(0)) ? "hw" : "sw");
> > +
> > + return 0;
> > +
> > +error_unregister:
> > + rzg2l_thermal_remove(pdev);
> > +
> > + return ret;
> > +}
> > +
> > +static const struct of_device_id rzg2l_thermal_dt_ids[] = {
> > + { .compatible = "renesas,rzg2l-tsu", },
> > + { /* sentinel */ }
> > +};
> > +MODULE_DEVICE_TABLE(of, rzg2l_thermal_dt_ids);
> > +
> > +static struct platform_driver rzg2l_thermal_driver = {
> > + .driver = {
> > + .name = "rzg2l_thermal",
> > + .of_match_table = rzg2l_thermal_dt_ids,
> > + },
> > + .probe = rzg2l_thermal_probe,
> > + .remove = rzg2l_thermal_remove,
> > +};
> > +module_platform_driver(rzg2l_thermal_driver);
> > +
> > +MODULE_DESCRIPTION("Renesas RZ/G2L TSU Thermal Sensor Driver");
> > +MODULE_AUTHOR("Biju Das <biju.das.jz@xxxxxxxxxxxxxx>");
> > +MODULE_LICENSE("GPL v2");
> > --
> > 2.17.1
> >
>
> --
> Kind Regards,
> Niklas Söderlund
