Re: [PATCH v1 3/3] thermal: ls2k: add thermal management support

From: Krzysztof Kozlowski
Date: Mon Sep 19 2022 - 03:11:41 EST


On 19/09/2022 05:49, Yinbo Zhu wrote:
> This patch adds the support for loongson2k thermal sensor controller,
> which can support maximum 3 sensors.
>
> It's based on thermal of framework:
> - Trip points defined in device tree.
> - Cpufreq as cooling device registered in loongson2k cpufreq driver.
> - Pwm fan as cooling device registered in hwmon pwm-fan driver.
>
> Signed-off-by: zhanghongchen <zhanghongchen@xxxxxxxxxxx>
> Signed-off-by: Yinbo Zhu <zhuyinbo@xxxxxxxxxxx>
> ---
> drivers/thermal/Kconfig | 10 ++
> drivers/thermal/Makefile | 1 +
> drivers/thermal/ls2k_thermal.c | 244 +++++++++++++++++++++++++++++++++
> 3 files changed, 255 insertions(+)
> create mode 100644 drivers/thermal/ls2k_thermal.c
>
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index e052dae614eb..04f5c044bc94 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 LOONGSON2K_THERMAL
> + tristate "Loongson 2K SOC series thermal driver"
> + depends on OF
> + default m

Why should it be module by default on x86 or ARM? See how other drivers
do it.

> + help
> + Support for Thermal driver found on Loongson 2K 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

(...)

> +
> +static int ls2k_thermal_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct resource *res;
> + struct ls2k_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));

There is a helper combining these two.

> + if (IS_ERR(data->regs)) {
> + dev_err(dev, "failed to get io address\n");

I think error msg can be skipped in such case. Core should print it.

> + return PTR_ERR(data->regs);
> + }
> +
> + /* get irq */
> + data->irq = platform_get_irq(pdev, 0);
> + if (data->irq < 0)
> + return data->irq;
> +
> + /* get id */
> + if (of_property_read_u32(dev->of_node, "id", &data->id)) {
> + dev_err(dev, "not found id property!\n");
> + data->id = LS2K_SOC_DEFAULT_SENSOR;
> + }
> +
> + if (data->id > LS2K_SOC_MAX_SENSOR_NUM) {
> + dev_err(dev, "sensor id error,must be in <0 ~ %d>\n",
> + LS2K_SOC_MAX_SENSOR_NUM);
> + return -EINVAL;
> + }
> +
> + writeb(0xff, data->regs + LS2K_TSENSOR_STATUS);
> +
> + ls2k_tsensor_set(data, 0, 0, false);
> +
> + data->tzd = devm_thermal_zone_of_sensor_register(&pdev->dev,
> + data->id, data,
> + &ls2k_of_thermal_ops);
> + if (IS_ERR(data->tzd)) {
> + ret = PTR_ERR(data->tzd);
> + data->tzd = NULL;
> + dev_err(&pdev->dev, "failed to register %d\n", ret);
> + return ret;
> + }
> +
> + ret = devm_request_threaded_irq(dev, data->irq,
> + ls2k_thermal_alarm_irq, ls2k_thermal_irq_thread,
> + IRQF_ONESHOT, "ls2k_thermal", data);
> + if (ret < 0) {
> + dev_err(dev, "failed to request alarm irq: %d\n", ret);
> + return ret;
> + }
> +
> + /*
> + * Thermal_zone doesn't enable hwmon as default,
> + * enable it here
> + */
> + data->tzd->tzp->no_hwmon = false;
> + ret = thermal_add_hwmon_sysfs(data->tzd);
> + if (ret) {
> + dev_err(dev, "failed to add hwmon sysfs interface %d\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +int ls2k_thermal_remove(struct platform_device *pdev)
> +{
> + struct ls2k_thermal_data *data = platform_get_drvdata(pdev);
> + int reg_off = data->id * 2;
> +
> + /* disable interrupt */
> + writew(0, data->regs + LS2K_TSENSOR_CTRL_LO + reg_off);
> + writew(0, data->regs + LS2K_TSENSOR_CTRL_HI + reg_off);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id of_ls2k_thermal_match[] = {
> + { .compatible = "loongson,2k-tsensor",},
> + { /* end */ }
> +};
> +MODULE_DEVICE_TABLE(of, of_ls2k_thermal_match);
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int ls2k_thermal_suspend(struct device *dev)
> +{
> + struct ls2k_thermal_data *data = dev_get_drvdata(dev);
> + int reg_off = data->id * 2;
> +
> + data->ctrl_low_val = readw(data->regs + LS2K_TSENSOR_CTRL_LO + reg_off);
> + data->ctrl_hi_val = readw(data->regs + LS2K_TSENSOR_CTRL_HI + reg_off);
> +
> + writew(0, data->regs + LS2K_TSENSOR_CTRL_LO + reg_off);
> + writew(0, data->regs + LS2K_TSENSOR_CTRL_HI + reg_off);
> +
> + return 0;
> +}
> +
> +static int ls2k_thermal_resume(struct device *dev)
> +{
> + struct ls2k_thermal_data *data = dev_get_drvdata(dev);
> + int reg_off = data->id * 2;
> +
> + writew(data->ctrl_low_val, data->regs + LS2K_TSENSOR_CTRL_LO + reg_off);
> + writew(data->ctrl_hi_val, data->regs + LS2K_TSENSOR_CTRL_HI + reg_off);
> +
> + return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(ls2k_thermal_pm_ops,
> + ls2k_thermal_suspend, ls2k_thermal_resume);
> +#endif
> +
> +static struct platform_driver ls2k_thermal_driver = {
> + .driver = {
> + .name = "ls2k_thermal",
> +#ifdef CONFIG_PM_SLEEP

pm_ptr() (and use same approach as its users - no need for ifdefs,
DEFINE_SIMPLE_DEV_PM_OPS)


> + .pm = &ls2k_thermal_pm_ops,
> +#endif
> + .of_match_table = of_ls2k_thermal_match,
> + },
> + .probe = ls2k_thermal_probe,
> + .remove = ls2k_thermal_remove,
> +};
> +module_platform_driver(ls2k_thermal_driver);


Best regards,
Krzysztof