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// SPDX-License-Identifier: GPL-2.0+
/*
* GPD Pocket fan controller driver
*
* Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com>
*/
#include <linux/acpi.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/thermal.h>
#include <linux/workqueue.h>
#define MAX_SPEED 3
static int temp_limits[3] = { 55000, 60000, 65000 };
module_param_array(temp_limits, int, NULL, 0444);
MODULE_PARM_DESC(temp_limits,
"Millicelsius values above which the fan speed increases");
static int hysteresis = 3000;
module_param(hysteresis, int, 0444);
MODULE_PARM_DESC(hysteresis,
"Hysteresis in millicelsius before lowering the fan speed");
static int speed_on_ac = 2;
module_param(speed_on_ac, int, 0444);
MODULE_PARM_DESC(speed_on_ac,
"minimum fan speed to allow when system is powered by AC");
struct gpd_pocket_fan_data {
struct device *dev;
struct thermal_zone_device *dts0;
struct thermal_zone_device *dts1;
struct gpio_desc *gpio0;
struct gpio_desc *gpio1;
struct delayed_work work;
int last_speed;
};
static void gpd_pocket_fan_set_speed(struct gpd_pocket_fan_data *fan, int speed)
{
if (speed == fan->last_speed)
return;
gpiod_direction_output(fan->gpio0, !!(speed & 1));
gpiod_direction_output(fan->gpio1, !!(speed & 2));
fan->last_speed = speed;
}
static int gpd_pocket_fan_min_speed(void)
{
if (power_supply_is_system_supplied())
return speed_on_ac;
else
return 0;
}
static void gpd_pocket_fan_worker(struct work_struct *work)
{
struct gpd_pocket_fan_data *fan =
container_of(work, struct gpd_pocket_fan_data, work.work);
int t0, t1, temp, speed, min_speed, i;
if (thermal_zone_get_temp(fan->dts0, &t0) ||
thermal_zone_get_temp(fan->dts1, &t1)) {
dev_warn(fan->dev, "Error getting temperature\n");
speed = MAX_SPEED;
goto set_speed;
}
temp = max(t0, t1);
speed = fan->last_speed;
min_speed = gpd_pocket_fan_min_speed();
/* Determine minimum speed */
for (i = min_speed; i < ARRAY_SIZE(temp_limits); i++) {
if (temp < temp_limits[i])
break;
}
if (speed < i)
speed = i;
/* Use hysteresis before lowering speed again */
for (i = min_speed; i < ARRAY_SIZE(temp_limits); i++) {
if (temp <= (temp_limits[i] - hysteresis))
break;
}
if (speed > i)
speed = i;
if (fan->last_speed <= 0 && speed)
speed = MAX_SPEED; /* kick start motor */
set_speed:
gpd_pocket_fan_set_speed(fan, speed);
/* When mostly idle (low temp/speed), slow down the poll interval. */
queue_delayed_work(system_wq, &fan->work,
msecs_to_jiffies(4000 / (speed + 1)));
}
static void gpd_pocket_fan_force_update(struct gpd_pocket_fan_data *fan)
{
fan->last_speed = -1;
mod_delayed_work(system_wq, &fan->work, 0);
}
static int gpd_pocket_fan_probe(struct platform_device *pdev)
{
struct gpd_pocket_fan_data *fan;
int i;
for (i = 0; i < ARRAY_SIZE(temp_limits); i++) {
if (temp_limits[i] < 40000 || temp_limits[i] > 70000) {
dev_err(&pdev->dev, "Invalid temp-limit %d (must be between 40000 and 70000)\n",
temp_limits[i]);
return -EINVAL;
}
}
if (hysteresis < 1000 || hysteresis > 10000) {
dev_err(&pdev->dev, "Invalid hysteresis %d (must be between 1000 and 10000)\n",
hysteresis);
return -EINVAL;
}
if (speed_on_ac < 0 || speed_on_ac > MAX_SPEED) {
dev_err(&pdev->dev, "Invalid speed_on_ac %d (must be between 0 and 3)\n",
speed_on_ac);
return -EINVAL;
}
fan = devm_kzalloc(&pdev->dev, sizeof(*fan), GFP_KERNEL);
if (!fan)
return -ENOMEM;
fan->dev = &pdev->dev;
INIT_DELAYED_WORK(&fan->work, gpd_pocket_fan_worker);
/* Note this returns a "weak" reference which we don't need to free */
fan->dts0 = thermal_zone_get_zone_by_name("soc_dts0");
if (IS_ERR(fan->dts0))
return -EPROBE_DEFER;
fan->dts1 = thermal_zone_get_zone_by_name("soc_dts1");
if (IS_ERR(fan->dts1))
return -EPROBE_DEFER;
fan->gpio0 = devm_gpiod_get_index(fan->dev, NULL, 0, GPIOD_ASIS);
if (IS_ERR(fan->gpio0))
return PTR_ERR(fan->gpio0);
fan->gpio1 = devm_gpiod_get_index(fan->dev, NULL, 1, GPIOD_ASIS);
if (IS_ERR(fan->gpio1))
return PTR_ERR(fan->gpio1);
gpd_pocket_fan_force_update(fan);
platform_set_drvdata(pdev, fan);
return 0;
}
static int gpd_pocket_fan_remove(struct platform_device *pdev)
{
struct gpd_pocket_fan_data *fan = platform_get_drvdata(pdev);
cancel_delayed_work_sync(&fan->work);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int gpd_pocket_fan_suspend(struct device *dev)
{
struct gpd_pocket_fan_data *fan = dev_get_drvdata(dev);
cancel_delayed_work_sync(&fan->work);
gpd_pocket_fan_set_speed(fan, gpd_pocket_fan_min_speed());
return 0;
}
static int gpd_pocket_fan_resume(struct device *dev)
{
struct gpd_pocket_fan_data *fan = dev_get_drvdata(dev);
gpd_pocket_fan_force_update(fan);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(gpd_pocket_fan_pm_ops,
gpd_pocket_fan_suspend,
gpd_pocket_fan_resume);
static struct acpi_device_id gpd_pocket_fan_acpi_match[] = {
{ "FAN02501" },
{},
};
MODULE_DEVICE_TABLE(acpi, gpd_pocket_fan_acpi_match);
static struct platform_driver gpd_pocket_fan_driver = {
.probe = gpd_pocket_fan_probe,
.remove = gpd_pocket_fan_remove,
.driver = {
.name = "gpd_pocket_fan",
.acpi_match_table = gpd_pocket_fan_acpi_match,
.pm = &gpd_pocket_fan_pm_ops,
},
};
module_platform_driver(gpd_pocket_fan_driver);
MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com");
MODULE_DESCRIPTION("GPD pocket fan driver");
MODULE_LICENSE("GPL");
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