Thermal / ACPI / video: add INT3406 thermal driver

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>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

4 files changed, 282 insertions, 25 deletions

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 3c3dc4a3d52c..d89d60c8b6cf 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");