/*
* Thermal device driver for DA9062 and DA9061
* Copyright (C) 2017 Dialog Semiconductor
*
* 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.
*
* 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.
*/
/* When over-temperature is reached, an interrupt from the device will be
* triggered. Following this event the interrupt will be disabled and
* periodic transmission of uevents (HOT trip point) should define the
* first level of temperature supervision. It is expected that any final
* implementation of the thermal driver will include a .notify() function
* to implement these uevents to userspace.
*
* These uevents are intended to indicate non-invasive temperature control
* of the system, where the necessary measures for cooling are the
* responsibility of the host software. Once the temperature falls again,
* the IRQ is re-enabled so the start of a new over-temperature event can
* be detected without constant software monitoring.
*/
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/thermal.h>
#include <linux/workqueue.h>
#include <linux/mfd/da9062/core.h>
#include <linux/mfd/da9062/registers.h>
/* Minimum, maximum and default polling millisecond periods are provided
* here as an example. It is expected that any final implementation to also
* include a modification of these settings to match the required
* application.
*/
#define DA9062_DEFAULT_POLLING_MS_PERIOD 3000
#define DA9062_MAX_POLLING_MS_PERIOD 10000
#define DA9062_MIN_POLLING_MS_PERIOD 1000
#define DA9062_MILLI_CELSIUS(t) ((t) * 1000)
struct da9062_thermal_config {
const char *name;
};
struct da9062_thermal {
struct da9062 *hw;
struct delayed_work work;
struct thermal_zone_device *zone;
enum thermal_device_mode mode;
struct mutex lock; /* protection for da9062_thermal temperature */
int temperature;
int irq;
const struct da9062_thermal_config *config;
struct device *dev;
};
static void da9062_thermal_poll_on(struct work_struct *work)
{
struct da9062_thermal *thermal = container_of(work,
struct da9062_thermal,
work.work);
unsigned long delay;
unsigned int val;
int ret;
/* clear E_TEMP */
ret = regmap_write(thermal->hw->regmap,
DA9062AA_EVENT_B,
DA9062AA_E_TEMP_MASK);
if (ret < 0) {
dev_err(thermal->dev,
"Cannot clear the TJUNC temperature status\n");
goto err_enable_irq;
}
/* Now read E_TEMP again: it is acting like a status bit.
* If over-temperature, then this status will be true.
* If not over-temperature, this status will be false.
*/
ret = regmap_read(thermal->hw->regmap,
DA9062AA_EVENT_B,
&val);
if (ret < 0) {
dev_err(thermal->dev,
"Cannot check the TJUNC temperature status\n");
goto err_enable_irq;
}
if (val & DA9062AA_E_TEMP_MASK) {
mutex_lock(&thermal->lock);
thermal->temperature = DA9062_MILLI_CELSIUS(125);
mutex_unlock(&thermal->lock);
thermal_zone_device_update(thermal->zone,
THERMAL_EVENT_UNSPECIFIED);
delay = msecs_to_jiffies(thermal->zone->passive_delay);
schedule_delayed_work(&thermal->work, delay);
return;
}
mutex_lock(&thermal->lock);
thermal->temperature = DA9062_MILLI_CELSIUS(0);
mutex_unlock(&thermal->lock);
thermal_zone_device_update(thermal->zone,
THERMAL_EVENT_UNSPECIFIED);
err_enable_irq:
enable_irq(thermal->irq);
}
static irqreturn_t da9062_thermal_irq_handler(int irq, void *data)
{
struct da9062_thermal *thermal = data;
disable_irq_nosync(thermal->irq);
schedule_delayed_work(&thermal->work, 0);
return IRQ_HANDLED;
}
static int da9062_thermal_get_mode(struct thermal_zone_device *z,
enum thermal_device_mode *mode)
{
struct da9062_thermal *thermal = z->devdata;
*mode = thermal->mode;
return 0;
}
static int da9062_thermal_get_trip_type(struct thermal_zone_device *z,
int trip,
enum thermal_trip_type *type)
{
struct da9062_thermal *thermal = z->devdata;
switch (trip) {
case 0:
*type = THERMAL_TRIP_HOT;
break;
default:
dev_err(thermal->dev,
"Driver does not support more than 1 trip-wire\n");
return -EINVAL;
}
return 0;
}
static int da9062_thermal_get_trip_temp(struct thermal_zone_device *z,
int trip,
int *temp)
{
struct da9062_thermal *thermal = z->devdata;
switch (trip) {
case 0:
*temp = DA9062_MILLI_CELSIUS(125);
break;
default:
dev_err(thermal->dev,
"Driver does not support more than 1 trip-wire\n");
return -EINVAL;
}
return 0;
}
static int da9062_thermal_get_temp(struct thermal_zone_device *z,
int *temp)
{
struct da9062_thermal *thermal = z->devdata;
mutex_lock(&thermal->lock);
*temp = thermal->temperature;
mutex_unlock(&thermal->lock);
return 0;
}
static struct thermal_zone_device_ops da9062_thermal_ops = {
.get_temp = da9062_thermal_get_temp,
.get_mode = da9062_thermal_get_mode,
.get_trip_type = da9062_thermal_get_trip_type,
.get_trip_temp = da9062_thermal_get_trip_temp,
};
static const struct da9062_thermal_config da9062_config = {
.name = "da9062-thermal",
};
static const struct of_device_id da9062_compatible_reg_id_table[] = {
{ .compatible = "dlg,da9062-thermal", .data = &da9062_config },
{ },
};
MODULE_DEVICE_TABLE(of, da9062_compatible_reg_id_table);
static int da9062_thermal_probe(struct platform_device *pdev)
{
struct da9062 *chip = dev_get_drvdata(pdev->dev.parent);
struct da9062_thermal *thermal;
unsigned int pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
const struct of_device_id *match;
int ret = 0;
match = of_match_node(da9062_compatible_reg_id_table,
pdev->dev.of_node);
if (!match)
return -ENXIO;
if (pdev->dev.of_node) {
if (!of_property_read_u32(pdev->dev.of_node,
"polling-delay-passive",
&pp_tmp)) {
if (pp_tmp < DA9062_MIN_POLLING_MS_PERIOD ||
pp_tmp > DA9062_MAX_POLLING_MS_PERIOD) {
dev_warn(&pdev->dev,
"Out-of-range polling period %d ms\n",
pp_tmp);
pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
}
}
}
thermal = devm_kzalloc(&pdev->dev, sizeof(struct da9062_thermal),
GFP_KERNEL);
if (!thermal) {
ret = -ENOMEM;
goto err;
}
thermal->config = match->data;
thermal->hw = chip;
thermal->mode = THERMAL_DEVICE_ENABLED;
thermal->dev = &pdev->dev;
INIT_DELAYED_WORK(&thermal->work, da9062_thermal_poll_on);
mutex_init(&thermal->lock);
thermal->zone = thermal_zone_device_register(thermal->config->name,
1, 0, thermal,
&da9062_thermal_ops, NULL, pp_tmp,
0);
if (IS_ERR(thermal->zone)) {
dev_err(&pdev->dev, "Cannot register thermal zone device\n");
ret = PTR_ERR(thermal->zone);
goto err;
}
dev_dbg(&pdev->dev,
"TJUNC temperature polling period set at %d ms\n",
thermal->zone->passive_delay);
ret = platform_get_irq_byname(pdev, "THERMAL");
if (ret < 0) {
dev_err(&pdev->dev, "Failed to get platform IRQ.\n");
goto err_zone;
}
thermal->irq = ret;
ret = request_threaded_irq(thermal->irq, NULL,
da9062_thermal_irq_handler,
IRQF_TRIGGER_LOW | IRQF_ONESHOT,
"THERMAL", thermal);
if (ret) {
dev_err(&pdev->dev,
"Failed to request thermal device IRQ.\n");
goto err_zone;
}
platform_set_drvdata(pdev, thermal);
return 0;
err_zone:
thermal_zone_device_unregister(thermal->zone);
err:
return ret;
}
static int da9062_thermal_remove(struct platform_device *pdev)
{
struct da9062_thermal *thermal = platform_get_drvdata(pdev);
free_irq(thermal->irq, thermal);
cancel_delayed_work_sync(&thermal->work);
thermal_zone_device_unregister(thermal->zone);
return 0;
}
static struct platform_driver da9062_thermal_driver = {
.probe = da9062_thermal_probe,
.remove = da9062_thermal_remove,
.driver = {
.name = "da9062-thermal",
.of_match_table = da9062_compatible_reg_id_table,
},
};
module_platform_driver(da9062_thermal_driver);
MODULE_AUTHOR("Steve Twiss");
MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da9062-thermal");
