// SPDX-License-Identifier: GPL-2.0-or-later
/*
* db8500_thermal.c - DB8500 Thermal Management Implementation
*
* Copyright (C) 2012 ST-Ericsson
* Copyright (C) 2012-2019 Linaro Ltd.
*
* Authors: Hongbo Zhang, Linus Walleij
*/
#include <linux/cpu_cooling.h>
#include <linux/interrupt.h>
#include <linux/mfd/dbx500-prcmu.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/thermal.h>
#define PRCMU_DEFAULT_MEASURE_TIME 0xFFF
#define PRCMU_DEFAULT_LOW_TEMP 0
/**
* db8500_thermal_points - the interpolation points that trigger
* interrupts
*/
static const unsigned long db8500_thermal_points[] = {
15000,
20000,
25000,
30000,
35000,
40000,
45000,
50000,
55000,
60000,
65000,
70000,
75000,
80000,
/*
* This is where things start to get really bad for the
* SoC and the thermal zones should be set up to trigger
* critical temperature at 85000 mC so we don't get above
* this point.
*/
85000,
90000,
95000,
100000,
};
struct db8500_thermal_zone {
struct thermal_zone_device *tz;
struct device *dev;
unsigned long interpolated_temp;
unsigned int cur_index;
};
/* Callback to get current temperature */
static int db8500_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
{
struct db8500_thermal_zone *th = thermal_zone_device_priv(tz);
/*
* TODO: There is no PRCMU interface to get temperature data currently,
* so a pseudo temperature is returned , it works for thermal framework
* and this will be fixed when the PRCMU interface is available.
*/
*temp = th->interpolated_temp;
return 0;
}
static const struct thermal_zone_device_ops thdev_ops = {
.get_temp = db8500_thermal_get_temp,
};
static void db8500_thermal_update_config(struct db8500_thermal_zone *th,
unsigned int idx,
unsigned long next_low,
unsigned long next_high)
{
prcmu_stop_temp_sense();
th->cur_index = idx;
th->interpolated_temp = (next_low + next_high)/2;
/*
* The PRCMU accept absolute temperatures in celsius so divide
* down the millicelsius with 1000
*/
prcmu_config_hotmon((u8)(next_low/1000), (u8)(next_high/1000));
prcmu_start_temp_sense(PRCMU_DEFAULT_MEASURE_TIME);
}
static irqreturn_t prcmu_low_irq_handler(int irq, void *irq_data)
{
struct db8500_thermal_zone *th = irq_data;
unsigned int idx = th->cur_index;
unsigned long next_low, next_high;
if (idx == 0)
/* Meaningless for thermal management, ignoring it */
return IRQ_HANDLED;
if (idx == 1) {
next_high = db8500_thermal_points[0];
next_low = PRCMU_DEFAULT_LOW_TEMP;
} else {
next_high = db8500_thermal_points[idx - 1];
next_low = db8500_thermal_points[idx - 2];
}
idx -= 1;
db8500_thermal_update_config(th, idx, next_low, next_high);
dev_dbg(th->dev,
"PRCMU set max %ld, min %ld\n", next_high, next_low);
thermal_zone_device_update(th->tz, THERMAL_EVENT_UNSPECIFIED);
return IRQ_HANDLED;
}
static irqreturn_t prcmu_high_irq_handler(int irq, void *irq_data)
{
struct db8500_thermal_zone *th = irq_data;
unsigned int idx = th->cur_index;
unsigned long next_low, next_high;
int num_points = ARRAY_SIZE(db8500_thermal_points);
if (idx < num_points - 1) {
next_high = db8500_thermal_points[idx+1];
next_low = db8500_thermal_points[idx];
idx += 1;
db8500_thermal_update_config(th, idx, next_low, next_high);
dev_dbg(th->dev,
"PRCMU set max %ld, min %ld\n", next_high, next_low);
} else if (idx == num_points - 1)
/* So we roof out 1 degree over the max point */
th->interpolated_temp = db8500_thermal_points[idx] + 1;
thermal_zone_device_update(th->tz, THERMAL_EVENT_UNSPECIFIED);
return IRQ_HANDLED;
}
static int db8500_thermal_probe(struct platform_device *pdev)
{
struct db8500_thermal_zone *th = NULL;
struct device *dev = &pdev->dev;
int low_irq, high_irq, ret = 0;
th = devm_kzalloc(dev, sizeof(*th), GFP_KERNEL);
if (!th)
return -ENOMEM;
th->dev = dev;
low_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_LOW");
if (low_irq < 0)
return low_irq;
ret = devm_request_threaded_irq(dev, low_irq, NULL,
prcmu_low_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
"dbx500_temp_low", th);
if (ret < 0) {
dev_err(dev, "failed to allocate temp low irq\n");
return ret;
}
high_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_HIGH");
if (high_irq < 0)
return high_irq;
ret = devm_request_threaded_irq(dev, high_irq, NULL,
prcmu_high_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
"dbx500_temp_high", th);
if (ret < 0) {
dev_err(dev, "failed to allocate temp high irq\n");
return ret;
}
/* register of thermal sensor and get info from DT */
th->tz = devm_thermal_of_zone_register(dev, 0, th, &thdev_ops);
if (IS_ERR(th->tz)) {
dev_err(dev, "register thermal zone sensor failed\n");
return PTR_ERR(th->tz);
}
dev_info(dev, "thermal zone sensor registered\n");
/* Start measuring at the lowest point */
db8500_thermal_update_config(th, 0, PRCMU_DEFAULT_LOW_TEMP,
db8500_thermal_points[0]);
platform_set_drvdata(pdev, th);
return 0;
}
static int db8500_thermal_suspend(struct platform_device *pdev,
pm_message_t state)
{
prcmu_stop_temp_sense();
return 0;
}
static int db8500_thermal_resume(struct platform_device *pdev)
{
struct db8500_thermal_zone *th = platform_get_drvdata(pdev);
/* Resume and start measuring at the lowest point */
db8500_thermal_update_config(th, 0, PRCMU_DEFAULT_LOW_TEMP,
db8500_thermal_points[0]);
return 0;
}
static const struct of_device_id db8500_thermal_match[] = {
{ .compatible = "stericsson,db8500-thermal" },
{},
};
MODULE_DEVICE_TABLE(of, db8500_thermal_match);
static struct platform_driver db8500_thermal_driver = {
.driver = {
.name = "db8500-thermal",
.of_match_table = db8500_thermal_match,
},
.probe = db8500_thermal_probe,
.suspend = db8500_thermal_suspend,
.resume = db8500_thermal_resume,
};
module_platform_driver(db8500_thermal_driver);
MODULE_AUTHOR("Hongbo Zhang <[email protected]>");
MODULE_DESCRIPTION("DB8500 thermal driver");
MODULE_LICENSE("GPL");
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