linux/drivers/thermal/da9062-thermal.c
Geert Uytterhoeven 760eea43f8 thermal: da9062/61: Prevent hardware access during system suspend
The workqueue used for monitoring the hardware may run while the device
is already suspended.  Fix this by using the freezable system workqueue
instead, cfr. commit 51e20d0e3a ("thermal: Prevent polling from
happening during system suspend").

Fixes: 608567aac3 ("thermal: da9062/61: Thermal junction temperature monitoring driver")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Steve Twiss <stwiss.opensource@diasemi.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2018-10-25 10:44:55 -07:00

316 lines
8.3 KiB
C

/*
* 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);
queue_delayed_work(system_freezable_wq, &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);
queue_delayed_work(system_freezable_wq, &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");