Re: [PATCH v3 update 4/4] Thermal: add INT3406 thermal driver

["Zhang, Rui" <rui.zhang@intel.com>]

On Mon, 2016-05-09 at 15:54 +0800, Aaron Lu wrote:
> INT3406 ACPI device object resembles an ACPI video output device, but its
> _BCM is said to be deprecated and should not be used. So we will make
> use of the raw interface to do the actual cooling.
> 
> Signed-off-by: Aaron Lu <aaron.lu@intel.com>

Acked-by: Zhang Rui <rui.zhang@intel.com>
> ---
> update: change copyright to 2016 and license to GPL v2 as suggested by Rui.
> 
>  drivers/thermal/Kconfig                           |  28 +--
>  drivers/thermal/int340x_thermal/Kconfig           |  42 ++++
>  drivers/thermal/int340x_thermal/Makefile          |   1 +
>  drivers/thermal/int340x_thermal/int3406_thermal.c | 236 ++++++++++++++++++++++
>  4 files changed, 282 insertions(+), 25 deletions(-)
>  create mode 100644 drivers/thermal/int340x_thermal/Kconfig
>  create mode 100644 drivers/thermal/int340x_thermal/int3406_thermal.c
> 
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index c37eedc35a24..cb1ba70ceaa7 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -338,31 +338,9 @@ config INTEL_QUARK_DTS_THERMAL
>  	  hot & critical. The critical trip point default value is set by
>  	  underlying BIOS/Firmware.
>  
> -config INT340X_THERMAL
> -	tristate "ACPI INT340X thermal drivers"
> -	depends on X86 && ACPI
> -	select THERMAL_GOV_USER_SPACE
> -	select ACPI_THERMAL_REL
> -	select ACPI_FAN
> -	select INTEL_SOC_DTS_IOSF_CORE
> -	select THERMAL_WRITABLE_TRIPS
> -	help
> -	  Newer laptops and tablets that use ACPI may have thermal sensors and
> -	  other devices with thermal control capabilities outside the core
> -	  CPU/SOC, for thermal safety reasons.
> -	  They are exposed for the OS to use via the INT3400 ACPI device object
> -	  as the master, and INT3401~INT340B ACPI device objects as the slaves.
> -	  Enable this to expose the temperature information and cooling ability
> -	  from these objects to userspace via the normal thermal framework.
> -	  This means that a wide range of applications and GUI widgets can show
> -	  the information to the user or use this information for making
> -	  decisions. For example, the Intel Thermal Daemon can use this
> -	  information to allow the user to select his laptop to run without
> -	  turning on the fans.
> -
> -config ACPI_THERMAL_REL
> -	tristate
> -	depends on ACPI
> +menu "ACPI INT340X thermal drivers"
> +source drivers/thermal/int340x_thermal/Kconfig
> +endmenu
>  
>  config INTEL_PCH_THERMAL
>  	tristate "Intel PCH Thermal Reporting Driver"
> diff --git a/drivers/thermal/int340x_thermal/Kconfig b/drivers/thermal/int340x_thermal/Kconfig
> new file mode 100644
> index 000000000000..0582bd12a239
> --- /dev/null
> +++ b/drivers/thermal/int340x_thermal/Kconfig
> @@ -0,0 +1,42 @@
> +#
> +# ACPI INT340x thermal drivers configuration
> +#
> +
> +config INT340X_THERMAL
> +	tristate "ACPI INT340X thermal drivers"
> +	depends on X86 && ACPI
> +	select THERMAL_GOV_USER_SPACE
> +	select ACPI_THERMAL_REL
> +	select ACPI_FAN
> +	select INTEL_SOC_DTS_IOSF_CORE
> +	help
> +	  Newer laptops and tablets that use ACPI may have thermal sensors and
> +	  other devices with thermal control capabilities outside the core
> +	  CPU/SOC, for thermal safety reasons.
> +	  They are exposed for the OS to use via the INT3400 ACPI device object
> +	  as the master, and INT3401~INT340B ACPI device objects as the slaves.
> +	  Enable this to expose the temperature information and cooling ability
> +	  from these objects to userspace via the normal thermal framework.
> +	  This means that a wide range of applications and GUI widgets can show
> +	  the information to the user or use this information for making
> +	  decisions. For example, the Intel Thermal Daemon can use this
> +	  information to allow the user to select his laptop to run without
> +	  turning on the fans.
> +
> +config ACPI_THERMAL_REL
> +	tristate
> +	depends on ACPI
> +
> +if INT340X_THERMAL
> +
> +config INT3406_THERMAL
> +	tristate "ACPI INT3406 display thermal driver"
> +	depends on ACPI_VIDEO
> +	help
> +	  The display thermal device represents the LED/LCD display panel
> +	  that may or may not include touch support. The main function of
> +	  the display thermal device is to allow control of the display
> +	  brightness in order to address a thermal condition or to reduce
> +	  power consumed by display device.
> +
> +endif
> diff --git a/drivers/thermal/int340x_thermal/Makefile b/drivers/thermal/int340x_thermal/Makefile
> index ba77a34f659f..df0df055e7ff 100644
> --- a/drivers/thermal/int340x_thermal/Makefile
> +++ b/drivers/thermal/int340x_thermal/Makefile
> @@ -3,4 +3,5 @@ obj-$(CONFIG_INT340X_THERMAL)	+= int340x_thermal_zone.o
>  obj-$(CONFIG_INT340X_THERMAL)	+= int3402_thermal.o
>  obj-$(CONFIG_INT340X_THERMAL)	+= int3403_thermal.o
>  obj-$(CONFIG_INT340X_THERMAL)	+= processor_thermal_device.o
> +obj-$(CONFIG_INT3406_THERMAL)	+= int3406_thermal.o
>  obj-$(CONFIG_ACPI_THERMAL_REL)	+= acpi_thermal_rel.o
> diff --git a/drivers/thermal/int340x_thermal/int3406_thermal.c b/drivers/thermal/int340x_thermal/int3406_thermal.c
> new file mode 100644
> index 000000000000..13d431cbd29e
> --- /dev/null
> +++ b/drivers/thermal/int340x_thermal/int3406_thermal.c
> @@ -0,0 +1,236 @@
> +/*
> + * 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 upper_limit_index;
> +	int lower_limit;
> +	int lower_limit_index;
> +	acpi_handle handle;
> +	struct acpi_video_device_brightness *br;
> +	struct backlight_device *raw_bd;
> +	struct thermal_cooling_device *cooling_dev;
> +};
> +
> +static int int3406_thermal_to_raw(int level, struct int3406_thermal_data *d)
> +{
> +	int max_level = d->br->levels[d->br->count - 1];
> +	int raw_max = d->raw_bd->props.max_brightness;
> +
> +	return level * raw_max / max_level;
> +}
> +
> +static int int3406_thermal_to_acpi(int level, struct int3406_thermal_data *d)
> +{
> +	int raw_max = d->raw_bd->props.max_brightness;
> +	int max_level = d->br->levels[d->br->count - 1];
> +
> +	return level * max_level / raw_max;
> +}
> +
> +static int
> +int3406_thermal_get_max_state(struct thermal_cooling_device *cooling_dev,
> +			      unsigned long *state)
> +{
> +	struct int3406_thermal_data *d = cooling_dev->devdata;
> +	int index = d->lower_limit_index ? d->lower_limit_index : 2;
> +
> +	*state = d->br->count - 1 - index;
> +	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 level, raw_level;
> +
> +	if (state > d->br->count - 3)
> +		return -EINVAL;
> +
> +	state = d->br->count - 1 - state;
> +	level = d->br->levels[state];
> +
> +	if ((d->upper_limit && level > d->upper_limit) ||
> +	    (d->lower_limit && level < d->lower_limit))
> +		return -EINVAL;
> +
> +	raw_level = int3406_thermal_to_raw(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 raw_level, level, i;
> +	int *levels = d->br->levels;
> +
> +	raw_level = d->raw_bd->props.brightness;
> +	level = int3406_thermal_to_acpi(raw_level, 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 close enough.
> +	 */
> +	for (i = 2; i < d->br->count; i++) {
> +		if (level < levels[i]) {
> +			if (i == 2)
> +				break;
> +			if ((level - levels[i - 1]) < (levels[i] - level))
> +				i--;
> +			break;
> +		}
> +	}
> +
> +	*state = d->br->count - 1 - i;
> +	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 = 0; 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;
> +	int index;
> +
> +	status = acpi_evaluate_integer(d->handle, "DDDL", NULL, &lower_limit);
> +	if (ACPI_SUCCESS(status)) {
> +		index = int3406_thermal_get_index(d->br->levels, d->br->count,
> +						  lower_limit);
> +		if (index > 0) {
> +			d->lower_limit = (int)lower_limit;
> +			d->lower_limit_index = index;
> +		}
> +	}
> +
> +	status = acpi_evaluate_integer(d->handle, "DDPC", NULL, &upper_limit);
> +	if (ACPI_SUCCESS(status)) {
> +		index = int3406_thermal_get_index(d->br->levels, d->br->count,
> +						  upper_limit);
> +		if (index > 0) {
> +			d->upper_limit = (int)upper_limit;
> +			d->upper_limit_index = index;
> +		}
> +	}
> +}
> +
> +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);
> +	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",
> +		   .owner = THIS_MODULE,
> +		   .acpi_match_table = int3406_thermal_match,
> +		   },
> +};
> +
> +module_platform_driver(int3406_thermal_driver);
> +
> +MODULE_DESCRIPTION("INT3406 Thermal driver");
> +MODULE_LICENSE("GPL v2");