linux/drivers/thermal/imx_thermal.c
Philipp Zabel 37713a1e8e thermal: imx: implement thermal alarm interrupt handling
Enable automatic measurements at 10 Hz and use the alarm interrupt to react
more quickly to sudden temperature changes above the passive or critical
temperature trip points.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2013-08-15 14:57:42 +08:00

542 lines
14 KiB
C

/*
* Copyright 2013 Freescale Semiconductor, Inc.
*
* 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.
*
*/
#include <linux/cpu_cooling.h>
#include <linux/cpufreq.h>
#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>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/thermal.h>
#include <linux/types.h>
#define REG_SET 0x4
#define REG_CLR 0x8
#define REG_TOG 0xc
#define MISC0 0x0150
#define MISC0_REFTOP_SELBIASOFF (1 << 3)
#define TEMPSENSE0 0x0180
#define TEMPSENSE0_ALARM_VALUE_SHIFT 20
#define TEMPSENSE0_ALARM_VALUE_MASK (0xfff << TEMPSENSE0_ALARM_VALUE_SHIFT)
#define TEMPSENSE0_TEMP_CNT_SHIFT 8
#define TEMPSENSE0_TEMP_CNT_MASK (0xfff << TEMPSENSE0_TEMP_CNT_SHIFT)
#define TEMPSENSE0_FINISHED (1 << 2)
#define TEMPSENSE0_MEASURE_TEMP (1 << 1)
#define TEMPSENSE0_POWER_DOWN (1 << 0)
#define TEMPSENSE1 0x0190
#define TEMPSENSE1_MEASURE_FREQ 0xffff
#define OCOTP_ANA1 0x04e0
/* The driver supports 1 passive trip point and 1 critical trip point */
enum imx_thermal_trip {
IMX_TRIP_PASSIVE,
IMX_TRIP_CRITICAL,
IMX_TRIP_NUM,
};
/*
* It defines the temperature in millicelsius for passive trip point
* that will trigger cooling action when crossed.
*/
#define IMX_TEMP_PASSIVE 85000
#define IMX_POLLING_DELAY 2000 /* millisecond */
#define IMX_PASSIVE_DELAY 1000
struct imx_thermal_data {
struct thermal_zone_device *tz;
struct thermal_cooling_device *cdev;
enum thermal_device_mode mode;
struct regmap *tempmon;
int c1, c2; /* See formula in imx_get_sensor_data() */
unsigned long temp_passive;
unsigned long temp_critical;
unsigned long alarm_temp;
unsigned long last_temp;
bool irq_enabled;
int irq;
};
static void imx_set_alarm_temp(struct imx_thermal_data *data,
signed long alarm_temp)
{
struct regmap *map = data->tempmon;
int alarm_value;
data->alarm_temp = alarm_temp;
alarm_value = (alarm_temp - data->c2) / data->c1;
regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_ALARM_VALUE_MASK);
regmap_write(map, TEMPSENSE0 + REG_SET, alarm_value <<
TEMPSENSE0_ALARM_VALUE_SHIFT);
}
static int imx_get_temp(struct thermal_zone_device *tz, unsigned long *temp)
{
struct imx_thermal_data *data = tz->devdata;
struct regmap *map = data->tempmon;
unsigned int n_meas;
bool wait;
u32 val;
if (data->mode == THERMAL_DEVICE_ENABLED) {
/* Check if a measurement is currently in progress */
regmap_read(map, TEMPSENSE0, &val);
wait = !(val & TEMPSENSE0_FINISHED);
} else {
/*
* Every time we measure the temperature, we will power on the
* temperature sensor, enable measurements, take a reading,
* disable measurements, power off the temperature sensor.
*/
regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
wait = true;
}
/*
* According to the temp sensor designers, it may require up to ~17us
* to complete a measurement.
*/
if (wait)
usleep_range(20, 50);
regmap_read(map, TEMPSENSE0, &val);
if (data->mode != THERMAL_DEVICE_ENABLED) {
regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
}
if ((val & TEMPSENSE0_FINISHED) == 0) {
dev_dbg(&tz->device, "temp measurement never finished\n");
return -EAGAIN;
}
n_meas = (val & TEMPSENSE0_TEMP_CNT_MASK) >> TEMPSENSE0_TEMP_CNT_SHIFT;
/* See imx_get_sensor_data() for formula derivation */
*temp = data->c2 + data->c1 * n_meas;
/* Update alarm value to next higher trip point */
if (data->alarm_temp == data->temp_passive && *temp >= data->temp_passive)
imx_set_alarm_temp(data, data->temp_critical);
if (data->alarm_temp == data->temp_critical && *temp < data->temp_passive) {
imx_set_alarm_temp(data, data->temp_passive);
dev_dbg(&tz->device, "thermal alarm off: T < %lu\n",
data->alarm_temp / 1000);
}
if (*temp != data->last_temp) {
dev_dbg(&tz->device, "millicelsius: %ld\n", *temp);
data->last_temp = *temp;
}
/* Reenable alarm IRQ if temperature below alarm temperature */
if (!data->irq_enabled && *temp < data->alarm_temp) {
data->irq_enabled = true;
enable_irq(data->irq);
}
return 0;
}
static int imx_get_mode(struct thermal_zone_device *tz,
enum thermal_device_mode *mode)
{
struct imx_thermal_data *data = tz->devdata;
*mode = data->mode;
return 0;
}
static int imx_set_mode(struct thermal_zone_device *tz,
enum thermal_device_mode mode)
{
struct imx_thermal_data *data = tz->devdata;
struct regmap *map = data->tempmon;
if (mode == THERMAL_DEVICE_ENABLED) {
tz->polling_delay = IMX_POLLING_DELAY;
tz->passive_delay = IMX_PASSIVE_DELAY;
regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
if (!data->irq_enabled) {
data->irq_enabled = true;
enable_irq(data->irq);
}
} else {
regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
tz->polling_delay = 0;
tz->passive_delay = 0;
if (data->irq_enabled) {
disable_irq(data->irq);
data->irq_enabled = false;
}
}
data->mode = mode;
thermal_zone_device_update(tz);
return 0;
}
static int imx_get_trip_type(struct thermal_zone_device *tz, int trip,
enum thermal_trip_type *type)
{
*type = (trip == IMX_TRIP_PASSIVE) ? THERMAL_TRIP_PASSIVE :
THERMAL_TRIP_CRITICAL;
return 0;
}
static int imx_get_crit_temp(struct thermal_zone_device *tz,
unsigned long *temp)
{
struct imx_thermal_data *data = tz->devdata;
*temp = data->temp_critical;
return 0;
}
static int imx_get_trip_temp(struct thermal_zone_device *tz, int trip,
unsigned long *temp)
{
struct imx_thermal_data *data = tz->devdata;
*temp = (trip == IMX_TRIP_PASSIVE) ? data->temp_passive :
data->temp_critical;
return 0;
}
static int imx_set_trip_temp(struct thermal_zone_device *tz, int trip,
unsigned long temp)
{
struct imx_thermal_data *data = tz->devdata;
if (trip == IMX_TRIP_CRITICAL)
return -EPERM;
if (temp > IMX_TEMP_PASSIVE)
return -EINVAL;
data->temp_passive = temp;
imx_set_alarm_temp(data, temp);
return 0;
}
static int imx_bind(struct thermal_zone_device *tz,
struct thermal_cooling_device *cdev)
{
int ret;
ret = thermal_zone_bind_cooling_device(tz, IMX_TRIP_PASSIVE, cdev,
THERMAL_NO_LIMIT,
THERMAL_NO_LIMIT);
if (ret) {
dev_err(&tz->device,
"binding zone %s with cdev %s failed:%d\n",
tz->type, cdev->type, ret);
return ret;
}
return 0;
}
static int imx_unbind(struct thermal_zone_device *tz,
struct thermal_cooling_device *cdev)
{
int ret;
ret = thermal_zone_unbind_cooling_device(tz, IMX_TRIP_PASSIVE, cdev);
if (ret) {
dev_err(&tz->device,
"unbinding zone %s with cdev %s failed:%d\n",
tz->type, cdev->type, ret);
return ret;
}
return 0;
}
static const struct thermal_zone_device_ops imx_tz_ops = {
.bind = imx_bind,
.unbind = imx_unbind,
.get_temp = imx_get_temp,
.get_mode = imx_get_mode,
.set_mode = imx_set_mode,
.get_trip_type = imx_get_trip_type,
.get_trip_temp = imx_get_trip_temp,
.get_crit_temp = imx_get_crit_temp,
.set_trip_temp = imx_set_trip_temp,
};
static int imx_get_sensor_data(struct platform_device *pdev)
{
struct imx_thermal_data *data = platform_get_drvdata(pdev);
struct regmap *map;
int t1, t2, n1, n2;
int ret;
u32 val;
map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
"fsl,tempmon-data");
if (IS_ERR(map)) {
ret = PTR_ERR(map);
dev_err(&pdev->dev, "failed to get sensor regmap: %d\n", ret);
return ret;
}
ret = regmap_read(map, OCOTP_ANA1, &val);
if (ret) {
dev_err(&pdev->dev, "failed to read sensor data: %d\n", ret);
return ret;
}
if (val == 0 || val == ~0) {
dev_err(&pdev->dev, "invalid sensor calibration data\n");
return -EINVAL;
}
/*
* Sensor data layout:
* [31:20] - sensor value @ 25C
* [19:8] - sensor value of hot
* [7:0] - hot temperature value
*/
n1 = val >> 20;
n2 = (val & 0xfff00) >> 8;
t2 = val & 0xff;
t1 = 25; /* t1 always 25C */
/*
* Derived from linear interpolation,
* Tmeas = T2 + (Nmeas - N2) * (T1 - T2) / (N1 - N2)
* We want to reduce this down to the minimum computation necessary
* for each temperature read. Also, we want Tmeas in millicelsius
* and we don't want to lose precision from integer division. So...
* milli_Tmeas = 1000 * T2 + 1000 * (Nmeas - N2) * (T1 - T2) / (N1 - N2)
* Let constant c1 = 1000 * (T1 - T2) / (N1 - N2)
* milli_Tmeas = (1000 * T2) + c1 * (Nmeas - N2)
* milli_Tmeas = (1000 * T2) + (c1 * Nmeas) - (c1 * N2)
* Let constant c2 = (1000 * T2) - (c1 * N2)
* milli_Tmeas = c2 + (c1 * Nmeas)
*/
data->c1 = 1000 * (t1 - t2) / (n1 - n2);
data->c2 = 1000 * t2 - data->c1 * n2;
/*
* Set the default passive cooling trip point to 20 °C below the
* maximum die temperature. Can be changed from userspace.
*/
data->temp_passive = 1000 * (t2 - 20);
/*
* The maximum die temperature is t2, let's give 5 °C cushion
* for noise and possible temperature rise between measurements.
*/
data->temp_critical = 1000 * (t2 - 5);
return 0;
}
static irqreturn_t imx_thermal_alarm_irq(int irq, void *dev)
{
struct imx_thermal_data *data = dev;
disable_irq_nosync(irq);
data->irq_enabled = false;
return IRQ_WAKE_THREAD;
}
static irqreturn_t imx_thermal_alarm_irq_thread(int irq, void *dev)
{
struct imx_thermal_data *data = dev;
dev_dbg(&data->tz->device, "THERMAL ALARM: T > %lu\n",
data->alarm_temp / 1000);
thermal_zone_device_update(data->tz);
return IRQ_HANDLED;
}
static int imx_thermal_probe(struct platform_device *pdev)
{
struct imx_thermal_data *data;
struct cpumask clip_cpus;
struct regmap *map;
int measure_freq;
int ret;
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "fsl,tempmon");
if (IS_ERR(map)) {
ret = PTR_ERR(map);
dev_err(&pdev->dev, "failed to get tempmon regmap: %d\n", ret);
return ret;
}
data->tempmon = map;
data->irq = platform_get_irq(pdev, 0);
if (data->irq < 0)
return data->irq;
ret = devm_request_threaded_irq(&pdev->dev, data->irq,
imx_thermal_alarm_irq, imx_thermal_alarm_irq_thread,
0, "imx_thermal", data);
if (ret < 0) {
dev_err(&pdev->dev, "failed to request alarm irq: %d\n", ret);
return ret;
}
platform_set_drvdata(pdev, data);
ret = imx_get_sensor_data(pdev);
if (ret) {
dev_err(&pdev->dev, "failed to get sensor data\n");
return ret;
}
/* Make sure sensor is in known good state for measurements */
regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ);
regmap_write(map, MISC0 + REG_SET, MISC0_REFTOP_SELBIASOFF);
regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
cpumask_set_cpu(0, &clip_cpus);
data->cdev = cpufreq_cooling_register(&clip_cpus);
if (IS_ERR(data->cdev)) {
ret = PTR_ERR(data->cdev);
dev_err(&pdev->dev,
"failed to register cpufreq cooling device: %d\n", ret);
return ret;
}
data->tz = thermal_zone_device_register("imx_thermal_zone",
IMX_TRIP_NUM,
BIT(IMX_TRIP_PASSIVE), data,
&imx_tz_ops, NULL,
IMX_PASSIVE_DELAY,
IMX_POLLING_DELAY);
if (IS_ERR(data->tz)) {
ret = PTR_ERR(data->tz);
dev_err(&pdev->dev,
"failed to register thermal zone device %d\n", ret);
cpufreq_cooling_unregister(data->cdev);
return ret;
}
/* Enable measurements at ~ 10 Hz */
regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ);
measure_freq = DIV_ROUND_UP(32768, 10); /* 10 Hz */
regmap_write(map, TEMPSENSE1 + REG_SET, measure_freq);
imx_set_alarm_temp(data, data->temp_passive);
regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
data->irq_enabled = true;
data->mode = THERMAL_DEVICE_ENABLED;
return 0;
}
static int imx_thermal_remove(struct platform_device *pdev)
{
struct imx_thermal_data *data = platform_get_drvdata(pdev);
struct regmap *map = data->tempmon;
/* Disable measurements */
regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
thermal_zone_device_unregister(data->tz);
cpufreq_cooling_unregister(data->cdev);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int imx_thermal_suspend(struct device *dev)
{
struct imx_thermal_data *data = dev_get_drvdata(dev);
struct regmap *map = data->tempmon;
u32 val;
regmap_read(map, TEMPSENSE0, &val);
if ((val & TEMPSENSE0_POWER_DOWN) == 0) {
/*
* If a measurement is taking place, wait for a long enough
* time for it to finish, and then check again. If it still
* does not finish, something must go wrong.
*/
udelay(50);
regmap_read(map, TEMPSENSE0, &val);
if ((val & TEMPSENSE0_POWER_DOWN) == 0)
return -ETIMEDOUT;
}
return 0;
}
static int imx_thermal_resume(struct device *dev)
{
/* Nothing to do for now */
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(imx_thermal_pm_ops,
imx_thermal_suspend, imx_thermal_resume);
static const struct of_device_id of_imx_thermal_match[] = {
{ .compatible = "fsl,imx6q-tempmon", },
{ /* end */ }
};
static struct platform_driver imx_thermal = {
.driver = {
.name = "imx_thermal",
.owner = THIS_MODULE,
.pm = &imx_thermal_pm_ops,
.of_match_table = of_imx_thermal_match,
},
.probe = imx_thermal_probe,
.remove = imx_thermal_remove,
};
module_platform_driver(imx_thermal);
MODULE_AUTHOR("Freescale Semiconductor, Inc.");
MODULE_DESCRIPTION("Thermal driver for Freescale i.MX SoCs");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:imx-thermal");