// SPDX-License-Identifier: GPL-2.0-only
/*
* INT3406 thermal driver for display participant device
*
* Copyright (C) 2016, Intel Corporation
* Authors: Aaron Lu <[email protected]>
*/
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/acpi.h>
#include <linux/backlight.h>
#include <linux/thermal.h>
#include <acpi/video.h>
#define INT3406_BRIGHTNESS_LIMITS_CHANGED 0x80
struct int3406_thermal_data {
int upper_limit;
int lower_limit;
acpi_handle handle;
struct acpi_video_device_brightness *br;
struct backlight_device *raw_bd;
struct thermal_cooling_device *cooling_dev;
};
/*
* According to the ACPI spec,
* "Each brightness level is represented by a number between 0 and 100,
* and can be thought of as a percentage. For example, 50 can be 50%
* power consumption or 50% brightness, as defined by the OEM."
*
* As int3406 device uses this value to communicate with the native
* graphics driver, we make the assumption that it represents
* the percentage of brightness only
*/
#define ACPI_TO_RAW(v, d) (d->raw_bd->props.max_brightness * v / 100)
#define RAW_TO_ACPI(v, d) (v * 100 / d->raw_bd->props.max_brightness)
static int
int3406_thermal_get_max_state(struct thermal_cooling_device *cooling_dev,
unsigned long *state)
{
struct int3406_thermal_data *d = cooling_dev->devdata;
*state = d->upper_limit - d->lower_limit;
return 0;
}
static int
int3406_thermal_set_cur_state(struct thermal_cooling_device *cooling_dev,
unsigned long state)
{
struct int3406_thermal_data *d = cooling_dev->devdata;
int acpi_level, raw_level;
if (state > d->upper_limit - d->lower_limit)
return -EINVAL;
acpi_level = d->br->levels[d->upper_limit - state];
raw_level = ACPI_TO_RAW(acpi_level, d);
return backlight_device_set_brightness(d->raw_bd, raw_level);
}
static int
int3406_thermal_get_cur_state(struct thermal_cooling_device *cooling_dev,
unsigned long *state)
{
struct int3406_thermal_data *d = cooling_dev->devdata;
int acpi_level;
int index;
acpi_level = RAW_TO_ACPI(d->raw_bd->props.brightness, d);
/*
* There is no 1:1 mapping between the firmware interface level
* with the raw interface level, we will have to find one that is
* right above it.
*/
for (index = d->lower_limit; index < d->upper_limit; index++) {
if (acpi_level <= d->br->levels[index])
break;
}
*state = d->upper_limit - index;
return 0;
}
static const struct thermal_cooling_device_ops video_cooling_ops = {
.get_max_state = int3406_thermal_get_max_state,
.get_cur_state = int3406_thermal_get_cur_state,
.set_cur_state = int3406_thermal_set_cur_state,
};
static int int3406_thermal_get_index(int *array, int nr, int value)
{
int i;
for (i = 2; i < nr; i++) {
if (array[i] == value)
break;
}
return i == nr ? -ENOENT : i;
}
static void int3406_thermal_get_limit(struct int3406_thermal_data *d)
{
acpi_status status;
unsigned long long lower_limit, upper_limit;
status = acpi_evaluate_integer(d->handle, "DDDL", NULL, &lower_limit);
if (ACPI_SUCCESS(status))
d->lower_limit = int3406_thermal_get_index(d->br->levels,
d->br->count, lower_limit);
status = acpi_evaluate_integer(d->handle, "DDPC", NULL, &upper_limit);
if (ACPI_SUCCESS(status))
d->upper_limit = int3406_thermal_get_index(d->br->levels,
d->br->count, upper_limit);
/* lower_limit and upper_limit should be always set */
d->lower_limit = d->lower_limit > 0 ? d->lower_limit : 2;
d->upper_limit = d->upper_limit > 0 ? d->upper_limit : d->br->count - 1;
}
static void int3406_notify(acpi_handle handle, u32 event, void *data)
{
if (event == INT3406_BRIGHTNESS_LIMITS_CHANGED)
int3406_thermal_get_limit(data);
}
static int int3406_thermal_probe(struct platform_device *pdev)
{
struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
struct int3406_thermal_data *d;
struct backlight_device *bd;
int ret;
if (!ACPI_HANDLE(&pdev->dev))
return -ENODEV;
d = devm_kzalloc(&pdev->dev, sizeof(*d), GFP_KERNEL);
if (!d)
return -ENOMEM;
d->handle = ACPI_HANDLE(&pdev->dev);
bd = backlight_device_get_by_type(BACKLIGHT_RAW);
if (!bd)
return -ENODEV;
d->raw_bd = bd;
ret = acpi_video_get_levels(ACPI_COMPANION(&pdev->dev), &d->br, NULL);
if (ret)
return ret;
int3406_thermal_get_limit(d);
d->cooling_dev = thermal_cooling_device_register(acpi_device_bid(adev),
d, &video_cooling_ops);
if (IS_ERR(d->cooling_dev))
goto err;
ret = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
int3406_notify, d);
if (ret)
goto err_cdev;
platform_set_drvdata(pdev, d);
return 0;
err_cdev:
thermal_cooling_device_unregister(d->cooling_dev);
err:
kfree(d->br);
return -ENODEV;
}
static void int3406_thermal_remove(struct platform_device *pdev)
{
struct int3406_thermal_data *d = platform_get_drvdata(pdev);
thermal_cooling_device_unregister(d->cooling_dev);
kfree(d->br);
}
static const struct acpi_device_id int3406_thermal_match[] = {
{"INT3406", 0},
{}
};
MODULE_DEVICE_TABLE(acpi, int3406_thermal_match);
static struct platform_driver int3406_thermal_driver = {
.probe = int3406_thermal_probe,
.remove_new = int3406_thermal_remove,
.driver = {
.name = "int3406 thermal",
.acpi_match_table = int3406_thermal_match,
},
};
module_platform_driver(int3406_thermal_driver);
MODULE_DESCRIPTION("INT3406 Thermal driver");
MODULE_LICENSE("GPL v2");
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