Message-ID: <8c54d305-c4fb-e0ab-3812-1a9debf05896@wanadoo.fr>
Date:   Thu, 3 Nov 2022 10:25:56 +0100
From:   Christophe JAILLET <christophe.jaillet@...adoo.fr>
To:     zhuyinbo@...ngson.cn
Cc:     amitk@...nel.org, daniel.lezcano@...aro.org,
        devicetree@...r.kernel.org, krzysztof.kozlowski+dt@...aro.org,
        linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
        liupeibao@...ngson.cn, rafael@...nel.org, robh+dt@...nel.org,
        rui.zhang@...el.com, zhanghongchen@...ngson.cn
Subject: Re: [PATCH v10 1/2] thermal: loongson-2: add thermal management
 support

Le 03/11/2022 à 09:34, Yinbo Zhu a écrit :
> This patch adds the support for Loongson-2 thermal sensor controller,
> which can support maximum 4 sensors.
> 
> It's based on thermal of framework:
>   - Trip points defined in device tree.
>   - Cpufreq as cooling device registered in Loongson-2 cpufreq driver.
>   - Pwm fan as cooling device registered in hwmon pwm-fan driver.
> 
> Signed-off-by: zhanghongchen <zhanghongchen-cXZgJK919ebM1kAEIRd3EQ@...lic.gmane.org>
> Signed-off-by: Yinbo Zhu <zhuyinbo-cXZgJK919ebM1kAEIRd3EQ@...lic.gmane.org>

Hi,
a few nit below, should there be a v11.

> ---
> Change in v10:
> 		1. Add all history change log information.
> Change in v9:
> 		1. Switch new API that use devm_thermal_of_zone_register
> 		   to replace previous interfaces.
> 		2. Add depend on LOONGARCH || COMPILE_TEST.
> Change in v8:
>                  1. Replace string loongson2/Loongson2/LOONGSON2 with loongson-2/
>                     Loongson-2/LOONGSON-2 in Kconfig and commit log and MAINTAINERS
> 		   files.
> Change in v7:
> 		1. Split the modification of patch 3 and merge it into this patch.
> 		2. Remove the unless code annotation to fix the compile warning
> 		   when compile C code with W=1.
> Change in v6:
> 		1. NO change, but other patch in this series of patches set has
> 		   changes.
> Change in v5:
> 		1. NO change, but other patch in this series of patches set has
> 		   changes.
> Change in v4:
> 		1. Fixup the compatible.
> Change in v3:
> 		1. Add a function to gain sensor id an remove dts id.
> Change in v2:
> 		1. Remove error msg printing when addr ioremap has error.
> 		2. Make loongson2 thermal driver was built-in by default.
> 		3. Replace ls2k with loongson2.
> 		4. Remove CONFIG_PM_SLEEP and set pm function type was
> 		   __maybe_unused.
> 
>   MAINTAINERS                         |   7 +
>   drivers/thermal/Kconfig             |  10 ++
>   drivers/thermal/Makefile            |   1 +
>   drivers/thermal/loongson2_thermal.c | 266 ++++++++++++++++++++++++++++
>   4 files changed, 284 insertions(+)
>   create mode 100644 drivers/thermal/loongson2_thermal.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 379945f82a64..37ab451d9258 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -12010,6 +12010,13 @@ F:	drivers/*/*loongarch*
>   F:	Documentation/loongarch/
>   F:	Documentation/translations/zh_CN/loongarch/
>   
> +LOONGSON-2 SOC SERIES THERMAL DRIVER
> +M:	zhanghongchen <zhanghongchen-cXZgJK919ebM1kAEIRd3EQ@...lic.gmane.org>
> +M:	Yinbo Zhu <zhuyinbo-cXZgJK919ebM1kAEIRd3EQ@...lic.gmane.org>
> +L:	linux-pm-u79uwXL29TY76Z2rM5mHXA@...lic.gmane.org
> +S:	Maintained
> +F:	drivers/thermal/loongson2_thermal.c
> +
>   LSILOGIC MPT FUSION DRIVERS (FC/SAS/SPI)
>   M:	Sathya Prakash <sathya.prakash-dY08KVG/lbpWk0Htik3J/w@...lic.gmane.org>
>   M:	Sreekanth Reddy <sreekanth.reddy-dY08KVG/lbpWk0Htik3J/w@...lic.gmane.org>
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index e052dae614eb..93d84bcb16dd 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 LOONGSON2_THERMAL
> +	tristate "Loongson-2 SoC series thermal driver"
> +	depends on LOONGARCH || COMPILE_TEST
> +	depends on OF
> +	help
> +	  Support for Thermal driver found on Loongson-2 SoC series platforms.
> +	  It supports one critical trip point and one passive trip point. The
> +	  cpufreq and the pwm fan is used as the cooling device to throttle
> +	  CPUs when the passive trip is crossed.
> +
>   endif
> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> index 2506c6c8ca83..02f3db809858 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_LOONGSON2_THERMAL)	+= loongson2_thermal.o
> diff --git a/drivers/thermal/loongson2_thermal.c b/drivers/thermal/loongson2_thermal.c
> new file mode 100644
> index 000000000000..87b07731f17e
> --- /dev/null
> +++ b/drivers/thermal/loongson2_thermal.c
> @@ -0,0 +1,266 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Author: zhanghongchen <zhanghongchen-cXZgJK919ebM1kAEIRd3EQ@...lic.gmane.org>
> + *         Yinbo Zhu <zhuyinbo-cXZgJK919ebM1kAEIRd3EQ@...lic.gmane.org>
> + * Copyright (C) 2022-2023 Loongson Technology Corporation Limited
> + */
> +
> +#include <linux/cpufreq.h>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/io.h>
> +#include <linux/of_device.h>
> +#include <linux/thermal.h>
> +#include "thermal_hwmon.h"
> +
> +#define LOONGSON2_SOC_MAX_SENSOR_NUM			4
> +
> +#define LOONGSON2_TSENSOR_CTRL_HI			0x0
> +#define LOONGSON2_TSENSOR_CTRL_LO			0x8
> +#define LOONGSON2_TSENSOR_STATUS			0x10
> +#define LOONGSON2_TSENSOR_OUT				0x14
> +
> +struct loongson2_thermal_data {
> +	struct thermal_zone_device *tzd;
> +	int irq;
> +	int id;
> +	void __iomem *regs;
> +	struct platform_device *pdev;
> +	u16 ctrl_low_val;
> +	u16 ctrl_hi_val;
> +};
> +
> +static int loongson2_thermal_set(struct loongson2_thermal_data *data,
> +					int low, int high, bool enable)
> +{
> +	u64 reg_ctrl = 0;
> +	int reg_off = data->id * 2;
> +
> +	if (low > high)
> +		return -EINVAL;
> +
> +	low = low < -100 ? -100 : low;

max()?

> +	high = high > 155 ? 155 : high;

min()?

> +
> +	low += 100;
> +	high += 100;
> +
> +	reg_ctrl |= low;
> +	reg_ctrl |= enable ? 0x100 : 0;
> +	writew(reg_ctrl, data->regs + LOONGSON2_TSENSOR_CTRL_LO + reg_off);
> +
> +	reg_ctrl = 0;
> +	reg_ctrl |= high;
> +	reg_ctrl |= enable ? 0x100 : 0;
> +	writew(reg_ctrl, data->regs + LOONGSON2_TSENSOR_CTRL_HI + reg_off);
> +
> +	return 0;
> +}
> +
> +static int loongson2_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
> +{
> +	u32 reg_val;
> +	struct loongson2_thermal_data *data = tz->devdata;
> +
> +	reg_val = readl(data->regs + LOONGSON2_TSENSOR_OUT);
> +	*temp = ((reg_val & 0xff) - 100) * 1000;
> +
> +	return 0;
> +}
> +
> +static int loongson2_thermal_get_sensor_id(void)
> +{
> +	int ret, id;
> +	struct of_phandle_args sensor_specs;
> +	struct device_node *np, *sensor_np;
> +
> +	np = of_find_node_by_name(NULL, "thermal-zones");
> +	if (!np)
> +		return -ENODEV;
> +
> +	sensor_np = of_get_next_child(np, NULL);
> +	ret = of_parse_phandle_with_args(sensor_np, "thermal-sensors",
> +			"#thermal-sensor-cells",
> +			0, &sensor_specs);
> +	if (ret) {
> +		of_node_put(np);
> +		of_node_put(sensor_np);
> +		return ret;
> +	}
> +
> +	if (sensor_specs.args_count >= 1) {
> +		id = sensor_specs.args[0];
> +		WARN(sensor_specs.args_count > 1,
> +				"%s: too many cells in sensor specifier %d\n",
> +				sensor_specs.np->name, sensor_specs.args_count);
> +	} else {
> +		id = 0;
> +	}
> +
> +	of_node_put(np);
> +	of_node_put(sensor_np);
> +
> +	return id;
> +}
> +
> +static irqreturn_t loongson2_thermal_alarm_irq(int irq, void *dev)
> +{
> +	struct loongson2_thermal_data *data = dev;
> +
> +	/* clear interrupt */
> +	writeb(0x3, data->regs + LOONGSON2_TSENSOR_STATUS);
> +
> +	disable_irq_nosync(irq);
> +
> +	return IRQ_WAKE_THREAD;
> +}
> +
> +static irqreturn_t loongson2_thermal_irq_thread(int irq, void *dev)
> +{
> +	struct loongson2_thermal_data *data = dev;
> +
> +	thermal_zone_device_update(data->tzd,
> +				   THERMAL_EVENT_UNSPECIFIED);
> +	enable_irq(data->irq);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int loongson2_thermal_set_trips(struct thermal_zone_device *tz, int low, int high)
> +{
> +	struct loongson2_thermal_data *data = tz->devdata;
> +
> +	return loongson2_thermal_set(data, low/1000, high/1000, true);
> +}
> +
> +static const struct thermal_zone_device_ops loongson2_of_thermal_ops = {
> +	.get_temp = loongson2_thermal_get_temp,
> +	.set_trips = loongson2_thermal_set_trips,
> +};
> +
> +static int loongson2_thermal_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct resource *res;
> +	struct loongson2_thermal_data *data;
> +	int ret;
> +
> +	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	data->pdev = pdev;
> +	platform_set_drvdata(pdev, data);
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	data->regs = devm_ioremap(dev, res->start, resource_size(res));
> +	if (IS_ERR(data->regs))
> +		return PTR_ERR(data->regs);
> +
> +	/* get irq */
> +	data->irq = platform_get_irq(pdev, 0);
> +	if (data->irq < 0)
> +		return data->irq;
> +
> +	/* get id */
> +	data->id = loongson2_thermal_get_sensor_id();
> +	if (data->id > LOONGSON2_SOC_MAX_SENSOR_NUM - 1 || data->id < 0) {
> +		dev_err(dev, "sensor id error,must be in <0 ~ %d>\n",
> +				LOONGSON2_SOC_MAX_SENSOR_NUM - 1);
> +		return -EINVAL;
> +	}
> +
> +	writeb(0xff, data->regs + LOONGSON2_TSENSOR_STATUS);
> +
> +	loongson2_thermal_set(data, 0, 0, false);
> +
> +	data->tzd = devm_thermal_of_zone_register(&pdev->dev,
> +							   data->id, data,
> +							   &loongson2_of_thermal_ops);
> +	if (IS_ERR(data->tzd)) {
> +		ret = PTR_ERR(data->tzd);
> +		data->tzd = NULL;

I don't think that NULLifying is needed here, PTR_ERR(data->tzd) could 
be used as-is in dev_err_probe(), ...

> +		dev_err(&pdev->dev, "failed to register %d\n", ret);

... here.
return dev_err_probe() saves a few lines of code.

> +		return ret;
> +	}
> +
> +	ret = devm_request_threaded_irq(dev, data->irq,
> +			loongson2_thermal_alarm_irq, loongson2_thermal_irq_thread,
> +			IRQF_ONESHOT, "loongson2_thermal", data);
> +	if (ret < 0) {
> +		dev_err(dev, "failed to request alarm irq: %d\n", ret);
> +		return ret;

return dev_err_probe() saves a few lines of code.

> +	}
> +
> +	/*
> +	 * Thermal_zone doesn't enable hwmon as default,
> +	 * enable it here
> +	 */
> +	data->tzd->tzp->no_hwmon = false;
> +	ret = thermal_add_hwmon_sysfs(data->tzd);

devm_thermal_add_hwmon_sysfs()?

> +	if (ret) {
> +		dev_err(dev, "failed to add hwmon sysfs interface %d\n", ret);
> +		return ret;

return dev_err_probe() saves a few lines of code.

> +	}
> +
> +	return 0;
> +}
> +
> +static int loongson2_thermal_remove(struct platform_device *pdev)
> +{
> +	struct loongson2_thermal_data *data = platform_get_drvdata(pdev);
> +	int reg_off = data->id * 2;
> +
> +	/* disable interrupt */
> +	writew(0, data->regs + LOONGSON2_TSENSOR_CTRL_LO + reg_off);
> +	writew(0, data->regs + LOONGSON2_TSENSOR_CTRL_HI + reg_off);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id of_loongson2_thermal_match[] = {
> +	{ .compatible = "loongson,ls2k-thermal",},
> +	{ /* end */ }
> +};
> +MODULE_DEVICE_TABLE(of, of_loongson2_thermal_match);
> +
> +static int __maybe_unused loongson2_thermal_suspend(struct device *dev)
> +{
> +	struct loongson2_thermal_data *data = dev_get_drvdata(dev);
> +	int reg_off = data->id * 2;
> +
> +	data->ctrl_low_val = readw(data->regs + LOONGSON2_TSENSOR_CTRL_LO + reg_off);
> +	data->ctrl_hi_val = readw(data->regs + LOONGSON2_TSENSOR_CTRL_HI + reg_off);
> +
> +	writew(0, data->regs + LOONGSON2_TSENSOR_CTRL_LO + reg_off);
> +	writew(0, data->regs + LOONGSON2_TSENSOR_CTRL_HI + reg_off);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused loongson2_thermal_resume(struct device *dev)
> +{
> +	struct loongson2_thermal_data *data = dev_get_drvdata(dev);
> +	int reg_off = data->id * 2;
> +
> +	writew(data->ctrl_low_val, data->regs + LOONGSON2_TSENSOR_CTRL_LO + reg_off);
> +	writew(data->ctrl_hi_val, data->regs + LOONGSON2_TSENSOR_CTRL_HI + reg_off);
> +
> +	return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(loongson2_thermal_pm_ops,
> +			 loongson2_thermal_suspend, loongson2_thermal_resume);
> +
> +static struct platform_driver loongson2_thermal_driver = {
> +	.driver = {
> +		.name		= "loongson2_thermal",
> +		.pm = &loongson2_thermal_pm_ops,
> +		.of_match_table = of_loongson2_thermal_match,
> +	},
> +	.probe	= loongson2_thermal_probe,
> +	.remove	= loongson2_thermal_remove,
> +};
> +module_platform_driver(loongson2_thermal_driver);

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