RE: [Patch v2 2/3] thermal: hisilicon: add thermal sensor driver for Hi3660

[Wangtao (Kevin, Kirin)]

On 2017/7/1 11:06, "Eduardo Valentin" <edubezval@xxxxxxxxx> wrote:> 
> Hey Tao,
> 
> On Thu, Jun 22, 2017 at 11:42:02AM +0800, Tao Wang wrote:
> > This patch adds the support for thermal sensor of Hi3660 SoC.
> > this will register sensors for thermal framework and use device
> > tree to bind cooling device.
> >
> > Signed-off-by: Tao Wang <kevin.wangtao@xxxxxxxxxxxxx>
> > Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
> > ---
> > Changes in v2:
> > - correct alphabet order
> > - correct compatible name
> >
> >  drivers/thermal/Kconfig          |   10 ++
> >  drivers/thermal/Makefile         |    1 +
> >  drivers/thermal/hi3660_thermal.c |  198
> ++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 209 insertions(+)
> >  create mode 100644 drivers/thermal/hi3660_thermal.c
> >
> > diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> > index b5b5fac..ed22a90 100644
> > --- a/drivers/thermal/Kconfig
> > +++ b/drivers/thermal/Kconfig
> > @@ -192,6 +192,16 @@ config THERMAL_EMULATION
> >  	  because userland can easily disable the thermal policy by simply
> >  	  flooding this sysfs node with low temperature values.
> >
> > +config HI3660_THERMAL
> > +	tristate "Hi3660 thermal driver"
> > +	depends on ARCH_HISI || COMPILE_TEST
> > +	depends on HAS_IOMEM
> > +	depends on OF
> > +	default y
> > +	help
> > +	  Enable this to plug Hi3660 thermal driver into the Linux thermal
> > +	  framework.
> > +
> >  config HISI_THERMAL
> >  	tristate "Hisilicon thermal driver"
> >  	depends on ARCH_HISI || COMPILE_TEST
> > diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> > index 094d703..f29d0a5 100644
> > --- a/drivers/thermal/Makefile
> > +++ b/drivers/thermal/Makefile
> > @@ -55,6 +55,7 @@ obj-$(CONFIG_INTEL_PCH_THERMAL)	+=
> intel_pch_thermal.o
> >  obj-$(CONFIG_ST_THERMAL)	+= st/
> >  obj-$(CONFIG_QCOM_TSENS)	+= qcom/
> >  obj-$(CONFIG_TEGRA_SOCTHERM)	+= tegra/
> > +obj-$(CONFIG_HI3660_THERMAL)	+= hi3660_thermal.o
> >  obj-$(CONFIG_HISI_THERMAL)     += hisi_thermal.o
> >  obj-$(CONFIG_MTK_THERMAL)	+= mtk_thermal.o
> >  obj-$(CONFIG_GENERIC_ADC_THERMAL)	+= thermal-generic-adc.o
> > diff --git a/drivers/thermal/hi3660_thermal.c
> b/drivers/thermal/hi3660_thermal.c
> > new file mode 100644
> > index 0000000..68fa9018
> > --- /dev/null
> > +++ b/drivers/thermal/hi3660_thermal.c
> > @@ -0,0 +1,198 @@
> > +/*
> > + *  linux/drivers/thermal/hi3660_thermal.c
> > + *
> > + *  Copyright (c) 2017 Hisilicon Limited.
> > + *  Copyright (c) 2017 Linaro Limited.
> > + *
> > + *  Author: Tao Wang <kevin.wangtao@xxxxxxxxxxxxx>
> > + *  Author: Leo Yan <leo.yan@xxxxxxxxxx>
> > + *
> > + *  This program is free software; you can redistribute it and/or modify
> > + *  it under the terms of the GNU General Public License as published by
> > + *  the Free Software Foundation; version 2 of the License.
> > + *
> > + *  This program is distributed in the hope that it will be useful,
> > + *  but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > + *  GNU General Public License for more details.
> > + *
> > + *  You should have received a copy of the GNU General Public License
> > + *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
> > + */
> > +
> > +#include <linux/clk.h>
> > +#include <linux/device.h>
> > +#include <linux/err.h>
> > +#include <linux/io.h>
> > +#include <linux/kernel.h>
> > +#include <linux/of.h>
> > +#include <linux/module.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/thermal.h>
> > +
> > +#include "thermal_core.h"
> > +
> > +#define HW_MAX_SENSORS			4
> > +#define HISI_MAX_SENSORS		6
> > +#define SENSOR_MAX			4
> > +#define SENSOR_AVG			5
> > +
> > +#define ADC_MIN		116
> > +#define ADC_MAX		922
> > +
> > +/* hi3660 Thermal Sensor Dev Structure */
> > +struct hi3660_thermal_sensor {
> > +	struct hi3660_thermal_data *thermal;
> > +	struct thermal_zone_device *tzd;
> > +
> > +	uint32_t id;
> > +};
> > +
> > +struct hi3660_thermal_data {
> > +	struct platform_device *pdev;
> > +	struct hi3660_thermal_sensor sensors[HISI_MAX_SENSORS];
> > +	void __iomem *thermal_base;
> > +};
> > +
> > +unsigned int sensor_reg_offset[HW_MAX_SENSORS] = { 0x1c, 0x5c, 0x9c,
> 0xdc };
> > +
> > +
> > +static int hi3660_thermal_get_temp(void *_sensor, int *temp)
> > +{
> > +	struct hi3660_thermal_sensor *sensor = _sensor;
> > +	struct hi3660_thermal_data *data = sensor->thermal;
> > +	unsigned int idx;
> > +	int val, average = 0, max = 0;
> > +
> > +	if (sensor->id < HW_MAX_SENSORS) {
> > +		val = readl(data->thermal_base + sensor_reg_offset[sensor-
> >id]);
> > +		val = clamp_val(val, ADC_MIN, ADC_MAX);
> > +	} else {
> > +		for (idx = 0; idx < HW_MAX_SENSORS; idx++) {
> > +			val = readl(data->thermal_base
> > +					+ sensor_reg_offset[idx]);
> > +			val = clamp_val(val, ADC_MIN, ADC_MAX);
> > +			average += val;
> > +			if (val > max)
> > +				max = val;
> > +		}
> > +
> > +		if (sensor->id == SENSOR_MAX)
> > +			val = max;
> > +		else if (sensor->id == SENSOR_AVG)
> > +			val = average / HW_MAX_SENSORS;
> > +	}
> > +
> > +	*temp = ((val - ADC_MIN) * 165000) / (ADC_MAX - ADC_MIN) -
> 40000;
> 
> Where do these constants come from (165000 and 40000) can these some

The sensor's temperature range is -40 to 125, that's the source of the constants.

> how
> be rearranged and described in DT (coefficients) and using the offset and
> slope fields?

That make sense, I will reconsider about it.

> 
> > +
> > +	return 0;
> > +}
> > +
> > +static struct thermal_zone_of_device_ops hi3660_of_thermal_ops = {
> > +	.get_temp = hi3660_thermal_get_temp,
> > +};
> > +
> > +static int hi3660_thermal_register_sensor(struct platform_device *pdev,
> > +		struct hi3660_thermal_data *data,
> > +		struct hi3660_thermal_sensor *sensor,
> > +		int index)
> > +{
> > +	int ret = 0;
> > +
> > +	sensor->id = index;
> > +	sensor->thermal = data;
> > +
> > +	sensor->tzd = devm_thermal_zone_of_sensor_register(&pdev-
> >dev,
> > +				sensor->id, sensor,
> &hi3660_of_thermal_ops);
> > +	if (IS_ERR(sensor->tzd)) {
> > +		ret = PTR_ERR(sensor->tzd);
> > +		sensor->tzd = NULL;
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> > +static void hi3660_thermal_toggle_sensor(struct hi3660_thermal_sensor
> *sensor,
> > +				       bool on)
> > +{
> > +	struct thermal_zone_device *tzd = sensor->tzd;
> > +
> > +	tzd->ops->set_mode(tzd,
> > +		on ? THERMAL_DEVICE_ENABLED :
> THERMAL_DEVICE_DISABLED);
> > +}
> > +
> > +static int hi3660_thermal_probe(struct platform_device *pdev)
> > +{
> > +	struct device *dev = &pdev->dev;
> > +	struct hi3660_thermal_data *data;
> > +	struct resource *res;
> > +	int ret = 0;
> > +	int i;
> > +
> > +	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> > +	if (!data)
> > +		return -ENOMEM;
> > +
> > +	data->pdev = pdev;
> > +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +	data->thermal_base = devm_ioremap_resource(dev, res);
> > +	if (IS_ERR(data->thermal_base)) {
> > +		dev_err(dev, "failed get reg base\n");
> > +		return -ENOMEM;
> > +	}
> > +
> > +	platform_set_drvdata(pdev, data);
> > +
> > +	for (i = 0; i < HISI_MAX_SENSORS; ++i) {
> > +		ret = hi3660_thermal_register_sensor(pdev, data,
> > +						     &data->sensors[i], i);
> > +		if (ret)
> > +			dev_err(&pdev->dev,
> > +				"failed to register thermal sensor%d: %d\n",
> > +				i, ret);
> 
> Do you really want to continue if some of the sensors fail to register?

Yes,  because currently we only use one of these sensors, the others will register fail 

> 
> > +		else
> > +			hi3660_thermal_toggle_sensor(&data->sensors[i],
> true);
> > +	}
> > +
> > +	dev_info(&pdev->dev, "Thermal Sensor Loaded\n");
> 
> Do you really need the above info in the kernel log?

That should be unnecessary, I will remove it.

> 
> > +	return 0;
> > +}
> > +
> > +static int hi3660_thermal_exit(struct platform_device *pdev)
> > +{
> > +	struct hi3660_thermal_data *data = platform_get_drvdata(pdev);
> > +	int i;
> > +
> > +	for (i = 0; i < HISI_MAX_SENSORS; i++) {
> > +		struct hi3660_thermal_sensor *sensor = &data->sensors[i];
> > +
> > +		if (!sensor->tzd)
> > +			continue;
> 
> Why are you considering a valid case of not registering all expected
> sensors?

Because currently we only use one of these sensors.

> > +
> > +		hi3660_thermal_toggle_sensor(sensor, false);
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct of_device_id hi3660_thermal_id_table[] = {
> > +	{ .compatible = "hisilicon,hi3660-thermal" },
> > +	{}
> > +};
> > +MODULE_DEVICE_TABLE(of, hi3660_thermal_id_table);
> > +
> > +static struct platform_driver hi3660_thermal_driver = {
> > +	.probe = hi3660_thermal_probe,
> > +	.remove = hi3660_thermal_exit,
> > +	.driver = {
> > +		.name = "hi3660_thermal",
> > +		.of_match_table = hi3660_thermal_id_table,
> > +	},
> > +};
> > +
> > +module_platform_driver(hi3660_thermal_driver);
> > +
> > +MODULE_AUTHOR("Tao Wang <kevin.wangtao@xxxxxxxxxxxxx>");
> > +MODULE_AUTHOR("Leo Yan <leo.yan@xxxxxxxxxx>");
> > +MODULE_DESCRIPTION("hi3660 thermal driver");
> > +MODULE_LICENSE("GPL v2");
> > --
> > 1.7.9.5
> >