Re: [PATCH RESEND v4 2/2] thermal: hisilicon: add new hisilicon thermal sensor driver

Xinwei Kong
2015-05-12T07:59:30Z

On 2015/5/12 9:29, Eduardo Valentin wrote:
> Dear Kongxinwei,
>
>
> Apologize for late answer. I really missed this one. Let's make it for
> the next merge window!
>
> Please find a couple of comments as follows.
>
>
> On Mon, May 04, 2015 at 10:52:20AM +0800, Xinwei Kong wrote:
>> From: kongxinwei <kong.kongxinwei@hisilicon.com>
>>
>> This patch adds the support for hisilicon thermal sensor, within
>> hisilicon SoC. there will register sensors for thermal framework
>> and use device tree to bind cooling device.
>>
>> Signed-off-by: Leo Yan <leo.yan@linaro.org>
>> Signed-off-by: kongxinwei <kong.kongxinwei@hisilicon.com>
>> ---
>> drivers/thermal/Kconfig | 8 +
>> drivers/thermal/Makefile | 1 +
>> drivers/thermal/hisi_thermal.c | 437 +++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 446 insertions(+)
>> create mode 100644 drivers/thermal/hisi_thermal.c
>
>
> Please, make sure you have a clean ./checkpatch.pl --strict output.
> Today, in this version, I see the following summary:
>
> # ./scripts/checkpatch.pl --strict /tmp/a
> total: 0 errors, 2 warnings, 7 checks, 455 lines checked
>
> /tmp/a has style problems, please review.
>
> If any of these errors are false positives, please report
> them to the maintainer, see CHECKPATCH in MAINTAINERS.
>
> Can you please clean them up?
>
>>
>> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
>> index af40db0..81aee01 100644
>> --- a/drivers/thermal/Kconfig
>> +++ b/drivers/thermal/Kconfig
>> @@ -136,6 +136,14 @@ config THERMAL_EMULATION
>> because userland can easily disable the thermal policy by simply
>> flooding this sysfs node with low temperature values.
>>
>> +config HISI_THERMAL
>> + tristate "Hisilicon thermal driver"
>> + depends on ARCH_HISI && CPU_THERMAL && OF
>> + help
>> + Enable this to plug hisilicon's thermal sensor driver into the Linux
>> + thermal framework. cpufreq is used as the cooling device to throttle
>> + CPUs when the passive trip is crossed.
>> +
>> config IMX_THERMAL
>> tristate "Temperature sensor driver for Freescale i.MX SoCs"
>> depends on CPU_THERMAL
>> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
>> index fa0dc48..08ae7ac 100644
>> --- a/drivers/thermal/Makefile
>> +++ b/drivers/thermal/Makefile
>> @@ -39,3 +39,4 @@ obj-$(CONFIG_TI_SOC_THERMAL) += ti-soc-thermal/
>> obj-$(CONFIG_INT340X_THERMAL) += int340x_thermal/
>> obj-$(CONFIG_ST_THERMAL) += st/
>> obj-$(CONFIG_TEGRA_SOCTHERM) += tegra_soctherm.o
>> +obj-$(CONFIG_HISI_THERMAL) += hisi_thermal.o
>> diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c
>> new file mode 100644
>> index 0000000..255c71b
>> --- /dev/null
>> +++ b/drivers/thermal/hisi_thermal.c
>> @@ -0,0 +1,437 @@
>> +/*
>> + * Hisilicon thermal sensor driver
>> + *
>> + * Copyright (c) 2014-2015 Hisilicon Limited.
>> + * Copyright (c) 2014-2015 Linaro Limited.
>> + *
>> + * Xinwei Kong <kong.kongxinwei@hisilicon.com>
>> + * Leo Yan <leo.yan@linaro.org>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + *
>> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
>> + * kind, whether express or implied; without even the implied warranty
>> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +#include <linux/cpufreq.h>
>
> I don't see why you need this header.
>
>> +#include <linux/delay.h>
>> +#include <linux/device.h>
>> +#include <linux/init.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/io.h>
>> +#include <linux/kernel.h>
>> +#include <linux/mfd/syscon.h>
>
> neither this
>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/of_device.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regmap.h>
>
> or this
>
>> +#include <linux/slab.h>
>> +#include <linux/thermal.h>
>> +#include <linux/types.h>
>> +
>> +#include "thermal_core.h"
>
>
> Please review the above includes. Leave only those you are using.
>
>> +
>> +#define TEMP0_TH (0x4)
>> +#define TEMP0_RST_TH (0x8)
>> +#define TEMP0_CFG (0xC)
>> +#define TEMP0_EN (0x10)
>> +#define TEMP0_INT_EN (0x14)
>> +#define TEMP0_INT_CLR (0x18)
>> +#define TEMP0_RST_MSK (0x1C)
>> +#define TEMP0_VALUE (0x28)
>> +
>> +#define HISI_TEMP_BASE (-60)
>> +#define HISI_TEMP_RESET (100000)
>> +
>> +#define HISI_MAX_SENSORS 4
>> +
>> +struct hisi_thermal_sensor {
>> + struct hisi_thermal_data *thermal;
>> + struct thermal_zone_device *tzd;
>> + const struct thermal_trip *trip;
>> +
>> + uint32_t id;
>> + uint32_t thres_temp;
>> + uint32_t reset_temp;
>
> reset_temp is never used in this driver.
>
>> +};
>> +

Ok, I will fix it and pay attention to the detail format. thx.

>> +struct hisi_thermal_data {
>> + struct mutex thermal_lock;
>> + struct platform_device *pdev;
>> + struct clk *clk;
>> +
>> + int irq, irq_bind_sensor;
>> + bool irq_enabled;
>> +
>> + unsigned int sensors_num;
>> + long sensor_temp[HISI_MAX_SENSORS];
>> + struct hisi_thermal_sensor sensors[HISI_MAX_SENSORS];
>
> Does it make sense to make sensor_temp part of hisi_thermal_sensors?
>
> Then you would access it through sensors.sensor_temp
>

I understand this way, use and test it

>> +
>> + void __iomem *regs;
>> +};
>> +
>> +/* in millicelsius */
>> +static inline int _step_to_temp(int step)
>> +{
>> + /*
>> + * Every step equals (1 * 200) / 255 celsius, and finally
>> + * need convert to millicelsius.
>> + */
>> + return (HISI_TEMP_BASE + (step * 200 / 255)) * 1000;
>> +}
>> +
>> +static inline int _temp_to_step(int temp)
>> +{
>> + return ((temp / 1000 - HISI_TEMP_BASE) * 255 / 200);
>> +}
>> +
>> +static long hisi_thermal_get_sensor_temp(struct hisi_thermal_data *data,
>> + struct hisi_thermal_sensor *sensor)
>> +{
>> + int val;
>> +
>> + mutex_lock(&data->thermal_lock);
>> +
>> + /* disable interrupt */
>> + writel(0x0, data->regs + TEMP0_INT_EN);
>> + writel(0x1, data->regs + TEMP0_INT_CLR);
>> +
>> + /* disable module firstly */
>> + writel(0x0, data->regs + TEMP0_EN);
>> +
>> + /* select sensor id */
>> + writel((sensor->id << 12), data->regs + TEMP0_CFG);
>> +
>> + /* enable module */
>> + writel(0x1, data->regs + TEMP0_EN);
>> +
>> + usleep_range(3000, 5000);
>> +
>> + val = readl(data->regs + TEMP0_VALUE);
>> + val = _step_to_temp(val);
>> +
>> + /* adjust for negative value */
>> + val = (val < 0) ? 0 : val;
>
> Why?
>
> What does val < 0 mean here? Does it mean negative temperature or an
> error?
>
> BTW, There is ongoing work to allow, at least representing, negative
> temperature.
>
consult hardware engineer to get some information which temperature range
is -40 ~ +160. I will deal it in the next version.

>
>> +
>> + mutex_unlock(&data->thermal_lock);
>> +
>> + return val;
>> +}
>> +
>> +static void hisi_thermal_bind_irq(struct hisi_thermal_data *data)
>> +{
>> + struct hisi_thermal_sensor *sensor;
>> +
>> + sensor = &data->sensors[data->irq_bind_sensor];
>> +
>> + mutex_lock(&data->thermal_lock);
>> +
>> + /* setting the hdak time */
>> + writel(0x0, data->regs + TEMP0_CFG);
>> +
>> + /* disable module firstly */
>> + writel(0x0, data->regs + TEMP0_RST_MSK);
>> + writel(0x0, data->regs + TEMP0_EN);
>> +
>
> Sorry, I get confused when you tell me you need to disable the module
> every time you need to read temp / change irq configuration.
>
> Is this really required?
>

yes. Soc have four sensor. They share a series of register. If not disabling
this module, the systerm will possible produce some problem.

For example, when setting the CPU0 sensor thres_temp is 50 degree. I will plan
to set and check the GPU sensor temp, (but the gpu sensor thres_temp require
70 degree). However, GPU sensor temp is 60 degree in fact. Before change
data->regs + TEMP0_TH register, the GPU sensor will produce interrupt under
50 degree. Because GPU and CPU0 share the TEMP0_TH register, so i will disable
this module.

>> + /* select sensor id */
>> + writel((sensor->id << 12), data->regs + TEMP0_CFG);
>> +
>> + /* enable for interrupt */
>> + writel(_temp_to_step(sensor->thres_temp)
>> + | 0x0FFFFFF00, data->regs + TEMP0_TH);
>
>
> nit: break after the | operator.
>
>> +
>> + writel(_temp_to_step(HISI_TEMP_RESET), data->regs + TEMP0_RST_TH);
>> +
>> + /* enable module */
>> + writel(0x1, data->regs + TEMP0_RST_MSK);
>> + writel(0x1, data->regs + TEMP0_EN);
>> +
>> + writel(0x0, data->regs + TEMP0_INT_CLR);
>> + writel(0x1, data->regs + TEMP0_INT_EN);
>> +
>> + usleep_range(3000, 5000);
>> +
>> + mutex_unlock(&data->thermal_lock);
>> +
> nit: remove empty line.
>
>> +}
>> +
>> +static void hisi_thermal_enable_sensor(struct hisi_thermal_data *data)
>> +{
>> + hisi_thermal_bind_irq(data);
>> +}
>> +
>> +static void hisi_thermal_disable_sensor(struct hisi_thermal_data *data)
>> +{
>> +
>> + mutex_lock(&data->thermal_lock);
>> +
>> + /* disable sensor module */
>> + writel(0x0, data->regs + TEMP0_INT_EN);
>> + writel(0x0, data->regs + TEMP0_RST_MSK);
>> + writel(0x0, data->regs + TEMP0_EN);
>> +
>> + mutex_unlock(&data->thermal_lock);
>> +
>
> nit: remove empty line.

ok. good comment

>
>> +}
>> +
>> +static int hisi_thermal_get_temp(void *_sensor, long *temp)
>> +{
>> + struct hisi_thermal_sensor *sensor = _sensor;
>> + struct hisi_thermal_data *data = sensor->thermal;
>> +
>> + int sensor_id = 0, i;
>> + long max_temp = 0;
>> +
>> + *temp = hisi_thermal_get_sensor_temp(data, sensor);
>> +
>> + data->sensor_temp[sensor->id] = *temp;
>> +
>> + for (i = 0; i < HISI_MAX_SENSORS; i++) {
>> + if (data->sensor_temp[i] >= max_temp) {
>> + max_temp = data->sensor_temp[i];
>> + sensor_id = i;
>> + }
>> + }
>> +
>> + data->irq_bind_sensor = sensor_id;
>
> I believe this irq_bind_sensor needs to be protected by a lock.
>
> You read it in t_irq context, write it here while getting temp, and read
> it in bind irq.
>
> I still don't follow why you need it though, can you please explain?
>
> In any case, seams to be racy, given that it is shared by the four
> sensors, but you don't lock it to use it.
>
>> +
>> + dev_dbg(&data->pdev->dev, "id=%d, irq=%d, temp=%ld, thres=%d\n",
>> + sensor->id, data->irq_enabled, *temp, sensor->thres_temp);
>> + /*
>> + * Bind irq to sensor for two cases:
>> + * Reenable alarm IRQ if temperature below threshold;
>> + * if irq has been enabled, always set it;
>> + */
>> + if (data->irq_enabled) {
>> + hisi_thermal_bind_irq(data);
>> + return 0;
>> + }
>> +
>> + if (max_temp < sensor->thres_temp) {
>> + data->irq_enabled = true;
>> + hisi_thermal_bind_irq(data);
>> + enable_irq(data->irq);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static struct thermal_zone_of_device_ops hisi_of_thermal_ops = {
>> + .get_temp = hisi_thermal_get_temp,
>> +};
>> +
>> +static irqreturn_t hisi_thermal_alarm_irq(int irq, void *dev)
>> +{
>> + struct hisi_thermal_data *data = dev;
>> +
>> + disable_irq_nosync(irq);
>> + data->irq_enabled = false;
>> +
>> + return IRQ_WAKE_THREAD;
>> +}
>> +
>> +static irqreturn_t hisi_thermal_alarm_irq_thread(int irq, void *dev)
>> +{
>> + struct hisi_thermal_data *data = dev;
>> + struct hisi_thermal_sensor *sensor;
>> + int i;
>> +
>> + sensor = &data->sensors[data->irq_bind_sensor];
>> +
>> + dev_crit(&data->pdev->dev, "THERMAL ALARM: T > %d\n",
>> + sensor->thres_temp / 1000);
>
> Do you really want to be printing this every time you receive an IRQ?
>
>> +
>> + for (i = 0; i < data->sensors_num; i++)
>> + thermal_zone_device_update(data->sensors[i].tzd);
>
>
> Can you please educate me on how this chip works?
>
> You receive a thermal alarm from the chip, does it really mean you have
> to update all thermal zones? Or do you have a way to check which sensor
> generated the alarm irq?
>
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static int hisi_thermal_register_sensor(struct platform_device *pdev,
>> + struct hisi_thermal_data *data,
>> + struct hisi_thermal_sensor *sensor,
>> + int index)
>> +{
>> + int ret, i;
>> +
>> + sensor->id = index;
>> + sensor->thermal = data;
>> +
>> + sensor->tzd = thermal_zone_of_sensor_register(&pdev->dev, sensor->id,
>> + sensor, &hisi_of_thermal_ops);
>> + if (IS_ERR(sensor->tzd)) {
>> + ret = PTR_ERR(sensor->tzd);
>> + dev_err(&pdev->dev, "failed to register sensor id %d: %d\n",
>> + sensor->id, ret);
>> + return ret;
>> + }
>> +
>> + sensor->trip = of_thermal_get_trip_points(sensor->tzd);
>> +
>> + for (i = 0; i < of_thermal_get_ntrips(sensor->tzd); i++) {
>> + if (sensor->trip[i].type == THERMAL_TRIP_PASSIVE) {
>
> what if you have more than one passive trip? You just care about the
> first?
>
>> + sensor->thres_temp = sensor->trip[i].temperature;
>
> Looks like you use sensor->trip only for filling thres_temp here. Does
> it make sense to use a local variable in this function, given you won't
> use sensor->trip anywhere else?
>
>> + break;
>> + }
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static const struct of_device_id of_hisi_thermal_match[] = {
>> + { .compatible = "hisilicon,tsensor" },
>> + { /* end */ }
>> +};
>> +MODULE_DEVICE_TABLE(of, of_hisi_thermal_match);
>> +
>> +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 hisi_thermal_data *data;
>> + struct resource *res;
>> + int i;
>> + int ret;
>> +
>> + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
>> + if (!data)
>> + return -ENOMEM;
>> +
>> + mutex_init(&data->thermal_lock);
>> + data->pdev = pdev;
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + data->regs = devm_ioremap_resource(&pdev->dev, res);
>> + if (IS_ERR(data->regs)) {
>> + dev_err(&pdev->dev, "failed to get io address\n");
>> + return PTR_ERR(data->regs);
>> + }
>> +
>> + data->irq = platform_get_irq(pdev, 0);
>> + if (data->irq < 0)
>> + return data->irq;
>> +
>> + ret = devm_request_threaded_irq(&pdev->dev, data->irq,
>> + hisi_thermal_alarm_irq, hisi_thermal_alarm_irq_thread,
>> + 0, "hisi_thermal", data);
>> + if (ret < 0) {
>> + dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
>> + return ret;
>> + }
>> +
>> + platform_set_drvdata(pdev, data);
>> +
>> + data->clk = devm_clk_get(&pdev->dev, "thermal_clk");
>> + if (IS_ERR(data->clk)) {
>> + ret = PTR_ERR(data->clk);
>> + if (ret != -EPROBE_DEFER)
>> + dev_err(&pdev->dev,
>> + "failed to get thermal clk: %d\n", ret);
>> + return ret;
>> + }
>> +
>> + /* enable clock for thermal */
>> + ret = clk_prepare_enable(data->clk);
>> + if (ret) {
>> + dev_err(&pdev->dev, "failed to enable thermal clk: %d\n", ret);
>> + return ret;
>> + }
>> +
>> + for (i = 0; i < HISI_MAX_SENSORS; ++i) {
>> + ret = hisi_thermal_register_sensor(pdev, data,
>> + &data->sensors[i], i);
>> + if (ret) {
>> + dev_err(&pdev->dev,
>> + "failed to register thermal sensor: %d\n", ret);
>> + goto err_get_sensor_data;
>> + }
>> + }
>> +
>> + hisi_thermal_enable_sensor(data);
>> + data->irq_enabled = true;
>> +
>> + for (i = 0; i < data->sensors_num; i++)
>> + hisi_thermal_toggle_sensor(&data->sensors[i], true);
>> +
>> + return 0;
>> +
>> +err_get_sensor_data:
>> + clk_disable_unprepare(data->clk);
>
> nit: empty line here to follow your pattern.
>
>> + return ret;
>> +}
>> +
>> +static int hisi_thermal_remove(struct platform_device *pdev)
>> +{
>> + struct hisi_thermal_data *data = platform_get_drvdata(pdev);
>> + int i;
>> +
>> + for (i = 0; i < data->sensors_num; i++) {
>> + struct hisi_thermal_sensor *sensor = &data->sensors[i];
>> +
>> + hisi_thermal_toggle_sensor(sensor, false);
>> + thermal_zone_of_sensor_unregister(&pdev->dev, sensor->tzd);
>> + }
>> +
>> + hisi_thermal_disable_sensor(data);
>> + clk_disable_unprepare(data->clk);
>
> nit: empty line here to follow your pattern.
>
>> + return 0;
>> +}
>> +
>> +#ifdef CONFIG_PM_SLEEP
>> +static int hisi_thermal_suspend(struct device *dev)
>> +{
>> + struct hisi_thermal_data *data = dev_get_drvdata(dev);
>> +
>> + hisi_thermal_disable_sensor(data);
>> + data->irq_enabled = false;
>> +
>> + clk_disable_unprepare(data->clk);
>> +
>> + return 0;
>> +}
>> +
>> +static int hisi_thermal_resume(struct device *dev)
>> +{
>> + struct hisi_thermal_data *data = dev_get_drvdata(dev);
>> +
>> + clk_prepare_enable(data->clk);
>> +
>> + data->irq_enabled = true;
>> + hisi_thermal_enable_sensor(data);
>> +
>> + return 0;
>> +}
>> +#endif
>> +
>> +static SIMPLE_DEV_PM_OPS(hisi_thermal_pm_ops,
>> + hisi_thermal_suspend, hisi_thermal_resume);
>> +
>> +static struct platform_driver hisi_thermal_driver = {
>> + .driver = {
>> + .name = "hisi_thermal",
>> + .owner = THIS_MODULE,
>> + .pm = &hisi_thermal_pm_ops,
>> + .of_match_table = of_hisi_thermal_match,
>
>
> nit: align on the '=' operator.
>
>> + },
>> + .probe = hisi_thermal_probe,
>> + .remove = hisi_thermal_remove,
>> +};
>> +
>> +module_platform_driver(hisi_thermal_driver);
>> +
>> +MODULE_AUTHOR("Xinwei Kong <kong.kongxinwei@hisilicon.com>");
>> +MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");
>> +MODULE_DESCRIPTION("Hisilicon thermal driver");
>> +MODULE_LICENSE("GPL v2");
>> --
>> 1.9.1
>>
>>