diff options
Diffstat (limited to 'drivers/thermal/int340x_thermal/int3406_thermal.c')
| -rw-r--r-- | drivers/thermal/int340x_thermal/int3406_thermal.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/drivers/thermal/int340x_thermal/int3406_thermal.c b/drivers/thermal/int340x_thermal/int3406_thermal.c new file mode 100644 index 000000000..f69ab026b --- /dev/null +++ b/drivers/thermal/int340x_thermal/int3406_thermal.c @@ -0,0 +1,213 @@ +/* + * INT3406 thermal driver for display participant device + * + * Copyright (C) 2016, Intel Corporation + * Authors: Aaron Lu <aaron.lu@intel.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#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 int 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); + return 0; +} + +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 = 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"); |