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/*
* ST Thermal Sensor Driver core routines
* Author: Ajit Pal Singh <ajitpal.singh@st.com>
*
* Copyright (C) 2003-2014 STMicroelectronics (R&D) Limited
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
*/
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include "st_thermal.h"
/* The Thermal Framework expects millidegrees */
#define mcelsius(temp) ((temp) * 1000)
/*
* Function to allocate regfields which are common
* between syscfg and memory mapped based sensors
*/
static int st_thermal_alloc_regfields(struct st_thermal_sensor *sensor)
{
struct device *dev = sensor->dev;
struct regmap *regmap = sensor->regmap;
const struct reg_field *reg_fields = sensor->cdata->reg_fields;
sensor->dcorrect = devm_regmap_field_alloc(dev, regmap,
reg_fields[DCORRECT]);
sensor->overflow = devm_regmap_field_alloc(dev, regmap,
reg_fields[OVERFLOW]);
sensor->temp_data = devm_regmap_field_alloc(dev, regmap,
reg_fields[DATA]);
if (IS_ERR(sensor->dcorrect) ||
IS_ERR(sensor->overflow) ||
IS_ERR(sensor->temp_data)) {
dev_err(dev, "failed to allocate common regfields\n");
return -EINVAL;
}
return sensor->ops->alloc_regfields(sensor);
}
static int st_thermal_sensor_on(struct st_thermal_sensor *sensor)
{
int ret;
struct device *dev = sensor->dev;
ret = clk_prepare_enable(sensor->clk);
if (ret) {
dev_err(dev, "failed to enable clk\n");
return ret;
}
ret = sensor->ops->power_ctrl(sensor, POWER_ON);
if (ret) {
dev_err(dev, "failed to power on sensor\n");
clk_disable_unprepare(sensor->clk);
}
return ret;
}
static int st_thermal_sensor_off(struct st_thermal_sensor *sensor)
{
int ret;
ret = sensor->ops->power_ctrl(sensor, POWER_OFF);
if (ret)
return ret;
clk_disable_unprepare(sensor->clk);
return 0;
}
static int st_thermal_calibration(struct st_thermal_sensor *sensor)
{
int ret;
unsigned int val;
struct device *dev = sensor->dev;
/* Check if sensor calibration data is already written */
ret = regmap_field_read(sensor->dcorrect, &val);
if (ret) {
dev_err(dev, "failed to read calibration data\n");
return ret;
}
if (!val) {
/*
* Sensor calibration value not set by bootloader,
* default calibration data to be used
*/
ret = regmap_field_write(sensor->dcorrect,
sensor->cdata->calibration_val);
if (ret)
dev_err(dev, "failed to set calibration data\n");
}
return ret;
}
/* Callback to get temperature from HW*/
static int st_thermal_get_temp(struct thermal_zone_device *th, int *temperature)
{
struct st_thermal_sensor *sensor = th->devdata;
struct device *dev = sensor->dev;
unsigned int temp;
unsigned int overflow;
int ret;
ret = regmap_field_read(sensor->overflow, &overflow);
if (ret)
return ret;
if (overflow)
return -EIO;
ret = regmap_field_read(sensor->temp_data, &temp);
if (ret)
return ret;
temp += sensor->cdata->temp_adjust_val;
temp = mcelsius(temp);
dev_dbg(dev, "temperature: %d\n", temp);
*temperature = temp;
return 0;
}
static int st_thermal_get_trip_type(struct thermal_zone_device *th,
int trip, enum thermal_trip_type *type)
{
struct st_thermal_sensor *sensor = th->devdata;
struct device *dev = sensor->dev;
switch (trip) {
case 0:
*type = THERMAL_TRIP_CRITICAL;
break;
default:
dev_err(dev, "invalid trip point\n");
return -EINVAL;
}
return 0;
}
static int st_thermal_get_trip_temp(struct thermal_zone_device *th,
int trip, int *temp)
{
struct st_thermal_sensor *sensor = th->devdata;
struct device *dev = sensor->dev;
switch (trip) {
case 0:
*temp = mcelsius(sensor->cdata->crit_temp);
break;
default:
dev_err(dev, "Invalid trip point\n");
return -EINVAL;
}
return 0;
}
static struct thermal_zone_device_ops st_tz_ops = {
.get_temp = st_thermal_get_temp,
.get_trip_type = st_thermal_get_trip_type,
.get_trip_temp = st_thermal_get_trip_temp,
};
int st_thermal_register(struct platform_device *pdev,
const struct of_device_id *st_thermal_of_match)
{
struct st_thermal_sensor *sensor;
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
const struct of_device_id *match;
int polling_delay;
int ret;
if (!np) {
dev_err(dev, "device tree node not found\n");
return -EINVAL;
}
sensor = devm_kzalloc(dev, sizeof(*sensor), GFP_KERNEL);
if (!sensor)
return -ENOMEM;
sensor->dev = dev;
match = of_match_device(st_thermal_of_match, dev);
if (!(match && match->data))
return -EINVAL;
sensor->cdata = match->data;
if (!sensor->cdata->ops)
return -EINVAL;
sensor->ops = sensor->cdata->ops;
ret = (sensor->ops->regmap_init)(sensor);
if (ret)
return ret;
ret = st_thermal_alloc_regfields(sensor);
if (ret)
return ret;
sensor->clk = devm_clk_get(dev, "thermal");
if (IS_ERR(sensor->clk)) {
dev_err(dev, "failed to fetch clock\n");
return PTR_ERR(sensor->clk);
}
if (sensor->ops->register_enable_irq) {
ret = sensor->ops->register_enable_irq(sensor);
if (ret)
return ret;
}
ret = st_thermal_sensor_on(sensor);
if (ret)
return ret;
ret = st_thermal_calibration(sensor);
if (ret)
goto sensor_off;
polling_delay = sensor->ops->register_enable_irq ? 0 : 1000;
sensor->thermal_dev =
thermal_zone_device_register(dev_name(dev), 1, 0, sensor,
&st_tz_ops, NULL, 0, polling_delay);
if (IS_ERR(sensor->thermal_dev)) {
dev_err(dev, "failed to register thermal zone device\n");
ret = PTR_ERR(sensor->thermal_dev);
goto sensor_off;
}
platform_set_drvdata(pdev, sensor);
return 0;
sensor_off:
st_thermal_sensor_off(sensor);
return ret;
}
EXPORT_SYMBOL_GPL(st_thermal_register);
int st_thermal_unregister(struct platform_device *pdev)
{
struct st_thermal_sensor *sensor = platform_get_drvdata(pdev);
st_thermal_sensor_off(sensor);
thermal_zone_device_unregister(sensor->thermal_dev);
return 0;
}
EXPORT_SYMBOL_GPL(st_thermal_unregister);
#ifdef CONFIG_PM_SLEEP
static int st_thermal_suspend(struct device *dev)
{
struct st_thermal_sensor *sensor = dev_get_drvdata(dev);
return st_thermal_sensor_off(sensor);
}
static int st_thermal_resume(struct device *dev)
{
int ret;
struct st_thermal_sensor *sensor = dev_get_drvdata(dev);
ret = st_thermal_sensor_on(sensor);
if (ret)
return ret;
ret = st_thermal_calibration(sensor);
if (ret)
return ret;
if (sensor->ops->enable_irq) {
ret = sensor->ops->enable_irq(sensor);
if (ret)
return ret;
}
return 0;
}
#endif
SIMPLE_DEV_PM_OPS(st_thermal_pm_ops, st_thermal_suspend, st_thermal_resume);
EXPORT_SYMBOL_GPL(st_thermal_pm_ops);
MODULE_AUTHOR("STMicroelectronics (R&D) Limited <ajitpal.singh@st.com>");
MODULE_DESCRIPTION("STMicroelectronics STi SoC Thermal Sensor Driver");
MODULE_LICENSE("GPL v2");
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