Re: [PATCH v2 3/3] thermal: cv180x: Add cv180x thermal driver support

[Jisheng Zhang <jszhang@kernel.org>]

On Tue, Jun 04, 2024 at 12:54:21PM +0000, Haylen Chu wrote:
> Add support for cv180x SoCs integrated thermal sensors.
> 
> Signed-off-by: Haylen Chu <heylenay@outlook.com>
> ---
>  drivers/thermal/Kconfig          |   6 +
>  drivers/thermal/Makefile         |   1 +
>  drivers/thermal/cv180x_thermal.c | 262 +++++++++++++++++++++++++++++++
>  3 files changed, 269 insertions(+)
>  create mode 100644 drivers/thermal/cv180x_thermal.c
> 
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 204ed89a3ec9..f53c973a361d 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -514,4 +514,10 @@ config LOONGSON2_THERMAL
>  	  is higher than the high temperature threshold or lower than the low
>  	  temperature threshold, the interrupt will occur.
>  
> +config CV180X_THERMAL
> +	tristate "Temperature sensor driver for Sophgo CV180X"
> +	help
> +	  If you say yes here you get support for thermal sensor integrated in
> +	  Sophgo CV180X SoCs.
> +
>  endif
> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> index 5cdf7d68687f..5b59bde8a579 100644
> --- a/drivers/thermal/Makefile
> +++ b/drivers/thermal/Makefile
> @@ -65,3 +65,4 @@ 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_LOONGSON2_THERMAL)	+= loongson2_thermal.o
> +obj-$(CONFIG_CV180X_THERMAL)	+= cv180x_thermal.o
> diff --git a/drivers/thermal/cv180x_thermal.c b/drivers/thermal/cv180x_thermal.c
> new file mode 100644
> index 000000000000..89425e2b75a2
> --- /dev/null
> +++ b/drivers/thermal/cv180x_thermal.c
> @@ -0,0 +1,262 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021 Sophgo Inc.
> + * Copyright (C) 2024 Haylen Chu <heylenay@outlook.com>
> + */
> +
> +#include <linux/bits.h>
> +#include <linux/clk.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/io.h>
> +#include <linux/thermal.h>

can we sort the headers?

> +
> +#define TEMPSEN_VERSION					0x0
> +#define TEMPSEN_CTRL					0x4
> +#define  TEMPSEN_CTRL_EN				BIT(0)
> +#define  TEMPSEN_CTRL_SEL_MASK				GENMASK(7, 4)
> +#define  TEMPSEN_CTRL_SEL_OFFSET			4
> +#define TEMPSEN_STATUS					0x8
> +#define TEMPSEN_SET					0xc
> +#define  TEMPSEN_SET_CHOPSEL_MASK			GENMASK(5, 4)
> +#define  TEMPSEN_SET_CHOPSEL_OFFSET			4
> +#define  TEMPSEN_SET_CHOPSEL_128T			0
> +#define  TEMPSEN_SET_CHOPSEL_256T			1
> +#define  TEMPSEN_SET_CHOPSEL_512T			2
> +#define  TEMPSEN_SET_CHOPSEL_1024T			3
> +#define  TEMPSEN_SET_ACCSEL_MASK			GENMASK(7, 6)
> +#define  TEMPSEN_SET_ACCSEL_OFFSET			6
> +#define  TEMPSEN_SET_ACCSEL_512T			0
> +#define  TEMPSEN_SET_ACCSEL_1024T			1
> +#define  TEMPSEN_SET_ACCSEL_2048T			2
> +#define  TEMPSEN_SET_ACCSEL_4096T			3
> +#define  TEMPSEN_SET_CYC_CLKDIV_MASK			GENMASK(15, 8)
> +#define  TEMPSEN_SET_CYC_CLKDIV_OFFSET			8
> +#define TEMPSEN_INTR_EN					0x10
> +#define TEMPSEN_INTR_CLR				0x14
> +#define TEMPSEN_INTR_STA				0x18
> +#define TEMPSEN_INTR_RAW				0x1c
> +#define TEMPSEN_RESULT(n)				(0x20 + (n) * 4)
> +#define  TEMPSEN_RESULT_RESULT_MASK			GENMASK(12, 0)
> +#define  TEMPSEN_RESULT_MAX_RESULT_MASK			GENMASK(28, 16)
> +#define  TEMPSEN_RESULT_CLR_MAX_RESULT			BIT(31)
> +#define TEMPSEN_AUTO_PERIOD				0x64
> +#define  TEMPSEN_AUTO_PERIOD_AUTO_CYCLE_MASK		GENMASK(23, 0)
> +#define  TEMPSEN_AUTO_PERIOD_AUTO_CYCLE_OFFSET		0
> +
> +struct cv180x_thermal_zone {
> +	struct device *dev;
> +	void __iomem *base;
> +	struct clk *clk_tempsen;
> +	u32 chop_period;
> +	u32 accum_period;
> +	u32 sample_cycle;
> +};
> +
> +static void cv180x_thermal_init(struct cv180x_thermal_zone *ctz)
> +{
> +	void __iomem *base = ctz->base;
> +	u32 regval;
> +
> +	writel(readl(base + TEMPSEN_INTR_RAW), base + TEMPSEN_INTR_CLR);
> +	writel(TEMPSEN_RESULT_CLR_MAX_RESULT, base + TEMPSEN_RESULT(0));
> +
> +	regval = readl(base + TEMPSEN_SET);
> +	regval &= ~TEMPSEN_SET_CHOPSEL_MASK;
> +	regval &= ~TEMPSEN_SET_ACCSEL_MASK;
> +	regval &= ~TEMPSEN_SET_CYC_CLKDIV_MASK;
> +	regval |= ctz->chop_period << TEMPSEN_SET_CHOPSEL_OFFSET;
> +	regval |= ctz->accum_period << TEMPSEN_SET_ACCSEL_OFFSET;
> +	regval |= 0x31 << TEMPSEN_SET_CYC_CLKDIV_OFFSET;
> +	writel(regval, base + TEMPSEN_SET);
> +
> +	regval = readl(base + TEMPSEN_AUTO_PERIOD);
> +	regval &= ~TEMPSEN_AUTO_PERIOD_AUTO_CYCLE_MASK;
> +	regval |= ctz->sample_cycle << TEMPSEN_AUTO_PERIOD_AUTO_CYCLE_OFFSET;
> +	writel(regval, base + TEMPSEN_AUTO_PERIOD);
> +
> +	regval = readl(base + TEMPSEN_CTRL);
> +	regval &= ~TEMPSEN_CTRL_SEL_MASK;
> +	regval |= 1 << TEMPSEN_CTRL_SEL_OFFSET;
> +	regval |= TEMPSEN_CTRL_EN;
> +	writel(regval, base + TEMPSEN_CTRL);
> +}
> +
> +static void cv180x_thermal_deinit(struct cv180x_thermal_zone *ct)
> +{
> +	void __iomem *base = ct->base;
> +	u32 regval;
> +
> +	regval = readl(base + TEMPSEN_CTRL);
> +	regval &= ~(TEMPSEN_CTRL_SEL_MASK | TEMPSEN_CTRL_EN);
> +	writel(regval, base + TEMPSEN_CTRL);
> +
> +	writel(readl(base + TEMPSEN_INTR_RAW), base + TEMPSEN_INTR_CLR);
> +}
> +
> +/*
> + *	Raw register value to temperature (mC) formula:
> + *
> + *		       read_val * 1000 * 716
> + *	Temperature = ----------------------- - 273000
> + *				divider
> + *
> + *	where divider should be ticks number of accumulation period,
> + *	e.g. 2048 for TEMPSEN_CTRL_ACCSEL_2048T
> + */
> +static int cv180x_calc_temp(struct cv180x_thermal_zone *ctz, u32 result)
> +{
> +	u32 divider = (u32)(512 * int_pow(2, ctz->accum_period));
> +
> +	return (result * 1000) * 716 / divider - 273000;
> +}
> +
> +static int cv180x_get_temp(struct thermal_zone_device *tdev, int *temperature)
> +{
> +	struct cv180x_thermal_zone *ctz = thermal_zone_device_priv(tdev);
> +	void __iomem *base = ctz->base;
> +	u32 result;
> +
> +	result = readl(base + TEMPSEN_RESULT(0)) & TEMPSEN_RESULT_RESULT_MASK;
> +	*temperature = cv180x_calc_temp(ctz, result);
> +
> +	return 0;
> +}
> +
> +static const struct thermal_zone_device_ops cv180x_thermal_ops = {
> +	.get_temp = cv180x_get_temp,
> +};
> +
> +static const struct of_device_id cv180x_thermal_of_match[] = {
> +	{ .compatible = "sophgo,cv1800-thermal" },
> +	{ .compatible = "sophgo,cv180x-thermal" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, cv180x_thermal_of_match);
> +
> +static int
> +cv180x_parse_dt(struct cv180x_thermal_zone *ctz)
> +{
> +	struct device_node *np = ctz->dev->of_node;
> +
> +	if (of_property_read_u32(np, "accumulation-period",
> +				 &ctz->accum_period)) {
> +		ctz->accum_period = TEMPSEN_SET_ACCSEL_2048T;
> +	} else {
> +		if (ctz->accum_period < TEMPSEN_SET_ACCSEL_512T ||
> +		    ctz->accum_period > TEMPSEN_SET_ACCSEL_4096T) {
> +			dev_err(ctz->dev, "invalid accumulation period %d\n",
> +				ctz->accum_period);
> +			return -EINVAL;
> +		}
> +	}
> +
> +	if (of_property_read_u32(np, "chop-period", &ctz->chop_period)) {
> +		ctz->chop_period = TEMPSEN_SET_CHOPSEL_1024T;
> +	} else {
> +		if (ctz->chop_period < TEMPSEN_SET_CHOPSEL_128T ||
> +		    ctz->chop_period > TEMPSEN_SET_CHOPSEL_1024T) {
> +			dev_err(ctz->dev, "invalid chop period %d\n",
> +				ctz->chop_period);
> +			return -EINVAL;
> +		}
> +	}
> +
> +	if (of_property_read_u32(np, "sample-cycle-us", &ctz->sample_cycle))
> +		ctz->sample_cycle = 1000000;
> +
> +	return 0;
> +}
> +
> +static int cv180x_thermal_probe(struct platform_device *pdev)
> +{
> +	struct cv180x_thermal_zone *ctz;
> +	struct thermal_zone_device *tz;
> +	struct resource *res;
> +	int ret;
> +
> +	ctz = devm_kzalloc(&pdev->dev, sizeof(*ctz), GFP_KERNEL);
> +	if (!ctz)
> +		return -ENOMEM;
> +
> +	ctz->dev = &pdev->dev;
> +
> +	ret = cv180x_parse_dt(ctz);
> +	if (ret)
> +		return dev_err_probe(&pdev->dev, ret, "failed to parse dt\n");
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	ctz->base = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(ctz->base))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(ctz->base),
> +				     "failed to map tempsen registers\n");
> +
> +	ctz->clk_tempsen = devm_clk_get(&pdev->dev, "clk_tempsen");

devm_clk_get_enabled maybe better for easy exit and error handling
code path. see below

And since the so called "clk_tempsen" is the only clk, it's better
to remove the clk name.

> +	if (IS_ERR(ctz->clk_tempsen))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(ctz->clk_tempsen),
> +				     "failed to get clk_tempsen\n");
> +
> +	clk_prepare_enable(ctz->clk_tempsen);
> +
> +	cv180x_thermal_init(ctz);
> +
> +	tz = devm_thermal_of_zone_register(&pdev->dev, 0, ctz,
> +					   &cv180x_thermal_ops);
> +	if (IS_ERR(tz))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(tz),
> +				     "failed to register thermal zone\n");

Missing undo the clk_prepare_enable. 

> +
> +	platform_set_drvdata(pdev, ctz);
> +
> +	return 0;
> +}
> +
> +static int cv180x_thermal_remove(struct platform_device *pdev)
> +{
> +	struct cv180x_thermal_zone *ctz = platform_get_drvdata(pdev);
> +
> +	cv180x_thermal_deinit(ctz);
> +	clk_disable_unprepare(ctz->clk_tempsen);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused cv180x_thermal_suspend(struct device *dev)
> +{
> +	struct cv180x_thermal_zone *ctz = dev_get_drvdata(dev);
> +
> +	cv180x_thermal_deinit(ctz);
> +	clk_disable_unprepare(ctz->clk_tempsen);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused cv180x_thermal_resume(struct device *dev)
> +{
> +	struct cv180x_thermal_zone *ctz = dev_get_drvdata(dev);
> +
> +	clk_prepare_enable(ctz->clk_tempsen);
> +	cv180x_thermal_init(ctz);
> +
> +	return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(cv180x_thermal_pm_ops,
> +			 cv180x_thermal_suspend, cv180x_thermal_resume);
> +
> +static struct platform_driver cv180x_thermal_driver = {
> +	.probe = cv180x_thermal_probe,
> +	.remove = cv180x_thermal_remove,
> +	.driver = {
> +		.name = "cv180x-thermal",
> +		.pm = &cv180x_thermal_pm_ops,
> +		.of_match_table = cv180x_thermal_of_match,
> +	},
> +};
> +
> +module_platform_driver(cv180x_thermal_driver);
> +
> +MODULE_DESCRIPTION("Sophgo CV180x thermal driver");
> +MODULE_AUTHOR("Haylen Chu <heylenay@outlook.com>");
> +MODULE_LICENSE("GPL");
> -- 
> 2.45.2
>