Hi Kevin,
On 29/08/2017 10:17, Tao Wang wrote: > From: Tao Wang <[email protected]> > > This patch adds the support for thermal sensor of Hi3660 SoC. for the Hi3660 SoC thermal sensor. > this will register sensors for thermal framework and use device > tree to bind cooling device. Is it possible to give a pointer to some documentation or to describe the hardware? An explanation of the adc min max coef[] range[] conversion would be nice. In addition, having the rational behind the average and the max would be nice. Do we really need both avg and max as virtual sensor? > Signed-off-by: Tao Wang <[email protected]> > Signed-off-by: Leo Yan <[email protected]> > --- > drivers/thermal/Kconfig | 13 +++ > drivers/thermal/Makefile | 1 + > drivers/thermal/hisi_tsensor.c | 209 > +++++++++++++++++++++++++++++++++++++++++ IMO, we don't need a new file, but merge this code with the current hisi_thermal.c driver. BTW, the hi6220 has also a tsensor which is different from this one. I suggest to base the hi3660 thermal driver on top of the cleanup I sent for the hi6220. > 3 files changed, 223 insertions(+) > create mode 100644 drivers/thermal/hisi_tsensor.c > > diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig > index b5b5fac..32f582d 100644 > --- a/drivers/thermal/Kconfig > +++ b/drivers/thermal/Kconfig > @@ -203,6 +203,19 @@ config HISI_THERMAL > thermal framework. cpufreq is used as the cooling device to throttle > CPUs when the passive trip is crossed. > > +config HISI_TSENSOR > + tristate "Hisilicon tsensor driver" > + depends on ARCH_HISI || COMPILE_TEST > + depends on HAS_IOMEM > + depends on OF > + default y > + help > + Enable this to plug Hisilicon's tsensor driver into the Linux thermal > + framework. Besides all the hardware sensors, this also support two > + virtual sensors, one for maximum of all the hardware sensor, and > + one for average of all the hardware sensor. > + Compitable with Hi3660 or higher. s/Compitable/Compatible/ > + > config IMX_THERMAL > tristate "Temperature sensor driver for Freescale i.MX SoCs" > depends on (ARCH_MXC && CPU_THERMAL) || COMPILE_TEST > diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile > index 094d703..8a16bd4 100644 > --- a/drivers/thermal/Makefile > +++ b/drivers/thermal/Makefile > @@ -56,6 +56,7 @@ obj-$(CONFIG_ST_THERMAL) += st/ > obj-$(CONFIG_QCOM_TSENS) += qcom/ > obj-$(CONFIG_TEGRA_SOCTHERM) += tegra/ > obj-$(CONFIG_HISI_THERMAL) += hisi_thermal.o > +obj-$(CONFIG_HISI_TSENSOR) += hisi_tsensor.o > obj-$(CONFIG_MTK_THERMAL) += mtk_thermal.o > obj-$(CONFIG_GENERIC_ADC_THERMAL) += thermal-generic-adc.o > obj-$(CONFIG_ZX2967_THERMAL) += zx2967_thermal.o > diff --git a/drivers/thermal/hisi_tsensor.c b/drivers/thermal/hisi_tsensor.c > new file mode 100644 > index 0000000..34cf2ba > --- /dev/null > +++ b/drivers/thermal/hisi_tsensor.c > @@ -0,0 +1,209 @@ > +/* > + * linux/drivers/thermal/hisi_tsensor.c > + * > + * Copyright (c) 2017 Hisilicon Limited. > + * Copyright (c) 2017 Linaro Limited. > + * > + * Author: Tao Wang <[email protected]> > + * Author: Leo Yan <[email protected]> > + * > + * 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 VIRTUAL_SENSORS 2 > + > +/* hisi Thermal Sensor Dev Structure */ > +struct hisi_thermal_sensor { > + struct hisi_thermal_data *thermal; > + struct thermal_zone_device *tzd; > + void __iomem *sensor_reg; > + unsigned int id; > +}; > + > +struct hisi_thermal_data { > + struct platform_device *pdev; > + struct hisi_thermal_sensor *sensors; > + unsigned int range[2]; > + unsigned int coef[2]; > + unsigned int max_hw_sensor; > +}; > + > +static int hisi_thermal_get_temp(void *_sensor, int *temp) > +{ > + struct hisi_thermal_sensor *sensor = _sensor; > + struct hisi_thermal_data *data = sensor->thermal; > + unsigned int idx, adc_min, adc_max, max_sensor; > + int val, average = 0, max = 0; > + > + adc_min = data->range[0]; > + adc_max = data->range[1]; > + max_sensor = data->max_hw_sensor; > + > + if (sensor->id < max_sensor) { > + val = readl(sensor->sensor_reg); > + val = clamp_val(val, adc_min, adc_max); That looks a bit fuzzy. Why not create a get_temp for physical sensor and another one for the virtual? So there will be a clear distinction between both. > + } else { > + for (idx = 0; idx < max_sensor; idx++) { > + val = readl(data->sensors[idx].sensor_reg); Below, it is assumed thermal_zone_of_sensor_register() can fail and sensor->tzd becomes NULL. But no check is done here with the sensor's tzd. Shall the code assume we take all the sensors even if a thermal zone failed to register ? > + val = clamp_val(val, adc_min, adc_max); > + average += val; > + if (val > max) > + max = val; > + } > + > + if (sensor->id == max_sensor) > + val = max; > + else > + val = average / max_sensor; > + } > > + *temp = ((val - adc_min) * data->coef[0]) / (adc_max - adc_min) > + + data->coef[1]; Pre-compute (adc_max - adc_min) at init time and check it is greater than zero, otherwise for a bad DT configuration we can end up with division by zero and crash the kernel (assuming having adc ranges in the DT is what we want). > + return 0; > +} > + > +static struct thermal_zone_of_device_ops hisi_of_thermal_ops = { > + .get_temp = hisi_thermal_get_temp, > +}; > + > +static void hisi_thermal_toggle_sensor(struct hisi_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 hisi_thermal_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct device_node *np = dev->of_node; > + struct hisi_thermal_data *data; > + struct hisi_thermal_sensor *sensor; > + struct resource *res; > + unsigned int max_sensor; > + int ret, i; > + > + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->pdev = pdev; > + ret = of_property_read_u32(np, "hisi,tsensors", &max_sensor); > + if (ret < 0) { > + dev_err(dev, "failed to get max sensor\n"); > + return -EINVAL; > + } > + data->max_hw_sensor = max_sensor; Do we really need a max sensor definition in the DT? Isn't it something we can deduce by looping with platform_get_resource below ? eg. while ((res = platform_get_resource(..., num_sensor++)) { ... } That said, I think we can assume there are 3 sensors always, no? > + data->sensors = devm_kzalloc(dev, > + sizeof(*data->sensors) * (max_sensor + VIRTUAL_SENSORS), > + GFP_KERNEL); > + if (IS_ERR(data->sensors)) { s/IS_ERR(data->sensors)/!data->sensors/ > + dev_err(dev, "failed to alloc sensors\n"); No message on memory allocation failure, there is already one from the mm framework. > + return -ENOMEM; > + } > + > + ret = of_property_read_u32_array(np, "hisi,coef", data->coef, 2); > + if (ret < 0) { > + dev_err(dev, "failed to get coef\n"); > + return -EINVAL; return ret; > + } > + > + ret = of_property_read_u32_array(np, "hisi,adc-range", data->range, 2); > + if (ret < 0) { > + dev_err(dev, "failed to get range\n"); > + return -EINVAL; return ret; > + } Are these data really needed through DT? Isn't it something we can hardcode? > + platform_set_drvdata(pdev, data); > + > + for (i = 0; i < max_sensor + VIRTUAL_SENSORS; ++i) { > + sensor = &data->sensors[i]; > + if (i < max_sensor) { > + res = platform_get_resource(pdev, IORESOURCE_MEM, i); Error check? > + sensor->sensor_reg = devm_ioremap_resource(dev, res); > + if (IS_ERR(sensor->sensor_reg)) { > + dev_err(dev, "failed to get reg base\n"); > + return -ENOMEM; s/-ENOMEM/PTR_ERR(sensor->sensor_reg)/ > + } > + } > + > + sensor->id = i; How can we deal with holes in the DT? > + sensor->thermal = data; > + sensor->tzd = thermal_zone_of_sensor_register(dev, > + i, sensor, &hisi_of_thermal_ops); > + if (IS_ERR(sensor->tzd)) { > + sensor->tzd = NULL; > + } else { > + hisi_thermal_toggle_sensor(sensor, true); > + dev_info(dev, "thermal sensor%d registered\n", i); > + } > + } > + > + return 0; > +} > + > +static int hisi_thermal_exit(struct platform_device *pdev) > +{ > + struct hisi_thermal_data *data = platform_get_drvdata(pdev); > + int i; > + > + for (i = 0; i < data->max_hw_sensor + VIRTUAL_SENSORS; i++) { > + struct hisi_thermal_sensor *sensor = &data->sensors[i]; > + > + if (!sensor->tzd) > + continue; > + > + hisi_thermal_toggle_sensor(sensor, false); > + thermal_zone_of_sensor_unregister(&pdev->dev, sensor->tzd); > + } > + > + return 0; > +} > + > +static const struct of_device_id hisi_thermal_id_table[] = { > + { .compatible = "hisilicon,hi3660-tsensor" }, > + {} > +}; > +MODULE_DEVICE_TABLE(of, hisi_thermal_id_table); > + > +static struct platform_driver hisi_thermal_driver = { > + .probe = hisi_thermal_probe, > + .remove = hisi_thermal_exit, > + .driver = { > + .name = "hisi_tsensor", > + .of_match_table = hisi_thermal_id_table, > + }, > +}; > + > +module_platform_driver(hisi_thermal_driver); > + > +MODULE_AUTHOR("Tao Wang <[email protected]>"); > +MODULE_AUTHOR("Leo Yan <[email protected]>"); > +MODULE_DESCRIPTION("hisi tsensor driver"); > +MODULE_LICENSE("GPL v2"); > -- <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | <http://twitter.com/#!/linaroorg> Twitter | <http://www.linaro.org/linaro-blog/> Blog
