1 files changed, 213 insertions, 0 deletions
diff --git a/drivers/thermal/intel/int340x_thermal/int3406_thermal.c b/drivers/thermal/intel/int340x_thermal/int3406_thermal.c
new file mode 100644
index 000000000000..f69ab026ba24
--- /dev/null
+++ b/drivers/thermal/intel/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");