Re: [PATCH v8 1/2] thermal: Add thermal driver for Sunplus

[Christophe JAILLET <christophe.jaillet@wanadoo.fr>]

Hi,

Le 03/05/2022 à 04:13, Li-hao Kuo a écrit :
> Add thermal driver for Sunplus.
> 
> Signed-off-by: Li-hao Kuo <lhjeff911-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> ---
> Changes in v8:
>   - Modify yaml file.
>     modify the setting compatible
>   - Change yaml file name.
>   - Modify driver.
>     mosdify and simply the nvmem setting and remove valiable
> 
>   MAINTAINERS                       |   6 ++
>   drivers/thermal/Kconfig           |  10 +++
>   drivers/thermal/Makefile          |   1 +
>   drivers/thermal/sunplus_thermal.c | 135 ++++++++++++++++++++++++++++++++++++++
>   4 files changed, 152 insertions(+)
>   create mode 100644 drivers/thermal/sunplus_thermal.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index edc96cd..82143ff 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -18896,6 +18896,12 @@ S:	Maintained
>   F:	Documentation/devicetree/bindings/spi/spi-sunplus-sp7021.yaml
>   F:	drivers/spi/spi-sunplus-sp7021.c
>   
> +SUNPLUS THERMAL DRIVER
> +M:	Li-hao Kuo <lhjeff911-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> +L:	linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> +S:	Maintained
> +F:	drivers/thermal/sunplus_thermal.c
> +
>   SUNPLUS UART DRIVER
>   M:	Hammer Hsieh <hammerh0314-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>   S:	Maintained
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 0e5cc94..595f507 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -504,4 +504,14 @@ config KHADAS_MCU_FAN_THERMAL
>   	  If you say yes here you get support for the FAN controlled
>   	  by the Microcontroller found on the Khadas VIM boards.
>   
> +config SUNPLUS_THERMAL
> +	tristate "Sunplus thermal drivers"
> +	depends on SOC_SP7021 || COMPILE_TEST
> +	help
> +	  This the Sunplus SP7021 thermal driver, which supports the primitive
> +	  temperature sensor embedded in Sunplus SP7021 SoC.
> +
> +	  If you have a Sunplus SP7021 platform say Y here and enable this option
> +	  to have support for thermal management
> +
>   endif
> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> index f0c36a1..38a76f9 100644
> --- a/drivers/thermal/Makefile
> +++ b/drivers/thermal/Makefile
> @@ -61,3 +61,4 @@ obj-$(CONFIG_UNIPHIER_THERMAL)	+= uniphier_thermal.o
>   obj-$(CONFIG_AMLOGIC_THERMAL)     += amlogic_thermal.o
>   obj-$(CONFIG_SPRD_THERMAL)	+= sprd_thermal.o
>   obj-$(CONFIG_KHADAS_MCU_FAN_THERMAL)	+= khadas_mcu_fan.o
> +obj-$(CONFIG_SUNPLUS_THERMAL)	+= sunplus_thermal.o
> diff --git a/drivers/thermal/sunplus_thermal.c b/drivers/thermal/sunplus_thermal.c
> new file mode 100644
> index 0000000..d4e22fc
> --- /dev/null
> +++ b/drivers/thermal/sunplus_thermal.c
> @@ -0,0 +1,135 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) Sunplus Inc.
> + * Author: Li-hao Kuo <lhjeff911-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/nvmem-consumer.h>
> +#include <linux/platform_device.h>
> +#include <linux/reset.h>
> +#include <linux/thermal.h>
> +
> +#define ENABLE_THERMAL		BIT(31)
> +#define SP_THERMAL_MASK		GENMASK(10, 0)
> +
> +#define TEMP_RATE		608
> +#define TEMP_BASE		3500
> +#define TEMP_OTP_BASE		1518
> +
> +#define SP_THERMAL_CTL0_REG	0x0000
> +#define SP_THERMAL_STS0_REG	0x0030
> +
> +/* common data structures */
> +struct sp_thermal_data {
> +	struct thermal_zone_device *pcb_tz;
> +	void __iomem *regs;
> +	int *otp_temp0;
> +};
> +
> +static int sunplus_get_otp_temp_coef(struct sp_thermal_data *sp_data, struct device *dev)
> +{
> +	struct nvmem_cell *cell;
> +	ssize_t otp_l;
> +
> +	cell = nvmem_cell_get(dev, "calib");
> +	if (IS_ERR(cell))
> +		return PTR_ERR(cell);
> +
> +	sp_data->otp_temp0 = nvmem_cell_read(cell, &otp_l);
> +	nvmem_cell_put(cell);
> +
> +	if (*sp_data->otp_temp0 == 0)
> +		*sp_data->otp_temp0 = TEMP_OTP_BASE;
> +
> +	return 0;
> +}
> +
> +/*
> + * There is a thermal sensor instance for SUNPLUS Soc
> + * T_CODE is the ADC of the thermal sensor
> + * T_CODE : 11 digits in total
> + * When remanufacturing, the 35 degree T_CODE will be read and stored in nvcell.
> + * otp_temp0 is the 35 degree T_CODE obtained from nvcell
> + * The function will get 35 degree T_CODE for thermal calibration.
> + * TEMP_RATE is the SUNPLUS thermal temperature slope.
> + */
> +
> +static int sp_thermal_get_sensor_temp(void *data, int *temp)
> +{
> +	struct sp_thermal_data *sp_data = data;
> +	int t_code;
> +
> +	t_code = readl(sp_data->regs + SP_THERMAL_STS0_REG);
> +	t_code = FIELD_GET(SP_THERMAL_MASK, t_code);
> +	*temp = ((*sp_data->otp_temp0 - t_code) * 10000 / TEMP_RATE) + TEMP_BASE;
> +	*temp *= 10;
> +	return 0;
> +}
> +
> +static const struct thermal_zone_of_device_ops sp_of_thermal_ops = {
> +	.get_temp = sp_thermal_get_sensor_temp,
> +};
> +
> +static int sunplus_thermal_probe(struct platform_device *pdev)
> +{
> +	struct sp_thermal_data *sp_data;
> +	int ret;
> +
> +	sp_data = devm_kzalloc(&pdev->dev, sizeof(*sp_data), GFP_KERNEL);
> +	if (!sp_data)
> +		return -ENOMEM;
> +
> +	sp_data->regs = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(sp_data->regs)) {
> +		dev_err(&pdev->dev, "resource get fail\n");
> +		return PTR_ERR(sp_data->regs);
> +	}
> +
> +	writel(ENABLE_THERMAL, sp_data->regs + SP_THERMAL_CTL0_REG);
> +
> +	platform_set_drvdata(pdev, sp_data);
> +	ret = sunplus_get_otp_temp_coef(sp_data, &pdev->dev);
> +	if (ret)
> +		return ret;
> +
> +	sp_data->pcb_tz = devm_thermal_zone_of_sensor_register(&pdev->dev,
> +							    0,
> +							    sp_data, &sp_of_thermal_ops);

sp_data->pcb_tz is the result of devm_thermal_zone_of_sensor_register() 
and devm_ functions usually don't need any clean-up. It is done 
automagically by the kernel itself.


> +	if (IS_ERR_OR_NULL(sp_data->pcb_tz))
> +		return PTR_ERR(sp_data->pcb_tz);
> +
> +	return ret;
> +}
> +
> +static int sunplus_thermal_remove(struct platform_device *pdev)
> +{
> +	struct sp_thermal_data *sp_data = platform_get_drvdata(pdev);
> +
> +	thermal_zone_device_unregister(sp_data->pcb_tz);

But here it is unregistered.

1) I would have expected that no unregister function is needed.
2) Should one be there, based on naming, 
thermal_zone_of_sensor_unregister() would look more consistent.

I know nothing about the thermal API, so don't take this comment too 
seriously. It just look odd to me when I gave it a look.

Just my 2c,

CJ


> +	return 0;
> +}
> +
> +static const struct of_device_id of_sunplus_thermal_ids[] = {
> +	{ .compatible = "sunplus,thermal" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, of_sunplus_thermal_ids);
> +
> +static struct platform_driver sunplus_thermal_driver = {
> +	.probe	= sunplus_thermal_probe,
> +	.remove = sunplus_thermal_remove,
> +	.driver	= {
> +		.name	= "sunplus-thermal",
> +		.of_match_table = of_sunplus_thermal_ids,
> +		},
> +};
> +module_platform_driver(sunplus_thermal_driver);
> +
> +MODULE_AUTHOR("Li-hao Kuo <lhjeff911-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>");
> +MODULE_DESCRIPTION("Thermal driver for sunplus SoC");
> +MODULE_LICENSE("GPL");