On 20/11/2021 20:47, Biju Das wrote:
> Add Thermal Sensor Unit(TSU) driver for RZ/G2L SoC.
Please give a technical description of the sensor as it is the first
submission.
> Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> ---
> v1->v2:
> * Removed devm_add_action_or_reset from probe.
> ---
> drivers/thermal/Kconfig | 9 ++
> drivers/thermal/Makefile | 1 +
> drivers/thermal/rzg2l_thermal.c | 235 ++++++++++++++++++++++++++++++++
> 3 files changed, 245 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..ea828c15dd1e
> --- /dev/null
> +++ b/drivers/thermal/rzg2l_thermal.c
> @@ -0,0 +1,235 @@
> +// 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)
cf. include/linux/units.h
> +#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;
> +}
roundup() | rounddown() ? (cf math.h)
> +
> +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;
Init in the declaration
What unit is the value returned ?
> + /* Read the ADC value 8 times with an interval of 20 microsecs */
Why do you have to do that ? + comment format
/*
*
*/
> + 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 */
With a proper comment in the loop, no need to add this one
> + ts_code_ave = result / TS_CODE_CAP_TIMES;
> + /* Curvature correction */
What is it? + comment format
> + dsensor = TS_CODE_AVE_SCALE(ts_code_ave) /
> + (TS_CODE_AVE_SCALE(1) + (ts_code_ave * 13));
> +
No litteral, s/13/a_macro/
> + /* Temperature calculation */
> + val = ((dsensor - priv->calib1) * (MCELSIUS(165) /
> + (priv->calib0 - priv->calib1))) - MCELSIUS(40);
Elaborate please + comment format
> +
> + /* Round value to device granularity setting */
Comment format
> + *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 */
Why + comment format. The comment should not describe what is doing the
code but *why*. It is obvious usleep(60) waits 60us
> + 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 void rzg2l_thermal_reset_assert_pm_disable_put(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);
> +}
> +
> +static int rzg2l_thermal_remove(struct platform_device *pdev)
> +{
> + struct rzg2l_thermal_priv *priv = dev_get_drvdata(&pdev->dev);
> +
> + thermal_remove_hwmon_sysfs(priv->zone);
> + rzg2l_thermal_reset_assert_pm_disable_put(pdev);
> +
> + return 0;
> +}
> +
> +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 err;
> + }
> +
> + 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);
dev_err(dev, "Can't register thermal zone: %d", ret);
> + goto err;
> + }
> +
> + priv->zone = zone;
> + priv->zone->tzp->no_hwmon = false;
> + ret = thermal_add_hwmon_sysfs(priv->zone);
> + if (ret)
> + goto err;
> +
> + dev_info(dev, "TSU probed with %s caliberation values",
> + rzg2l_thermal_read(priv, OTPTSUTRIM_REG(0)) ? "hw" : "sw");
s/dev_info/dev_debug/
> + return 0;
> +
> +err:
> + rzg2l_thermal_reset_assert_pm_disable_put(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");
>
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