From: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Date: Fri, 11 Feb 2022 08:09:28 -0800
Subject: ACPI: fan: Separate file for attributes creation
Patch-mainline: v5.18-rc1
Git-commit: 00ae053a0533155d830da27070a931e6fa747327
References: jsc#PED-1408

Move the functionality of creation of sysfs attributes under acpi device
to a new file fan_attr.c. This cleans up the core fan code, which just
use thermal sysfs interface. The original fan.c is renamed to
fan_core.c.

No functional changes are expected.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Lee, Chun-Yi <jlee@suse.com>
---
 drivers/acpi/Makefile   |    3 
 drivers/acpi/fan.c      |  496 ------------------------------------------------
 drivers/acpi/fan.h      |   35 +++
 drivers/acpi/fan_attr.c |   86 ++++++++
 drivers/acpi/fan_core.c |  416 ++++++++++++++++++++++++++++++++++++++++
 5 files changed, 540 insertions(+), 496 deletions(-)
 create mode 100644 drivers/acpi/fan_attr.c
 rename drivers/acpi/{fan.c => fan_core.c} (80%)

--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -80,6 +80,9 @@ obj-$(CONFIG_ACPI_AC) 		+= ac.o
 obj-$(CONFIG_ACPI_BUTTON)	+= button.o
 obj-$(CONFIG_ACPI_TINY_POWER_BUTTON)	+= tiny-power-button.o
 obj-$(CONFIG_ACPI_FAN)		+= fan.o
+fan-objs			:= fan_core.o
+fan-objs			+= fan_attr.o
+
 obj-$(CONFIG_ACPI_VIDEO)	+= video.o
 obj-$(CONFIG_ACPI_TAD)		+= acpi_tad.o
 obj-$(CONFIG_ACPI_PCI_SLOT)	+= pci_slot.o
--- a/drivers/acpi/fan.c
+++ /dev/null
@@ -1,496 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- *  acpi_fan.c - ACPI Fan Driver ($Revision: 29 $)
- *
- *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
- *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/types.h>
-#include <linux/uaccess.h>
-#include <linux/thermal.h>
-#include <linux/acpi.h>
-#include <linux/platform_device.h>
-#include <linux/sort.h>
-
-#include "fan.h"
-
-MODULE_AUTHOR("Paul Diefenbaugh");
-MODULE_DESCRIPTION("ACPI Fan Driver");
-MODULE_LICENSE("GPL");
-
-static int acpi_fan_probe(struct platform_device *pdev);
-static int acpi_fan_remove(struct platform_device *pdev);
-
-static const struct acpi_device_id fan_device_ids[] = {
-	ACPI_FAN_DEVICE_IDS,
-	{"", 0},
-};
-MODULE_DEVICE_TABLE(acpi, fan_device_ids);
-
-#ifdef CONFIG_PM_SLEEP
-static int acpi_fan_suspend(struct device *dev);
-static int acpi_fan_resume(struct device *dev);
-static const struct dev_pm_ops acpi_fan_pm = {
-	.resume = acpi_fan_resume,
-	.freeze = acpi_fan_suspend,
-	.thaw = acpi_fan_resume,
-	.restore = acpi_fan_resume,
-};
-#define FAN_PM_OPS_PTR (&acpi_fan_pm)
-#else
-#define FAN_PM_OPS_PTR NULL
-#endif
-
-#define ACPI_FPS_NAME_LEN	20
-
-struct acpi_fan_fps {
-	u64 control;
-	u64 trip_point;
-	u64 speed;
-	u64 noise_level;
-	u64 power;
-	char name[ACPI_FPS_NAME_LEN];
-	struct device_attribute dev_attr;
-};
-
-struct acpi_fan_fif {
-	u64 revision;
-	u64 fine_grain_ctrl;
-	u64 step_size;
-	u64 low_speed_notification;
-};
-
-struct acpi_fan {
-	bool acpi4;
-	struct acpi_fan_fif fif;
-	struct acpi_fan_fps *fps;
-	int fps_count;
-	struct thermal_cooling_device *cdev;
-};
-
-static struct platform_driver acpi_fan_driver = {
-	.probe = acpi_fan_probe,
-	.remove = acpi_fan_remove,
-	.driver = {
-		.name = "acpi-fan",
-		.acpi_match_table = fan_device_ids,
-		.pm = FAN_PM_OPS_PTR,
-	},
-};
-
-/* thermal cooling device callbacks */
-static int fan_get_max_state(struct thermal_cooling_device *cdev, unsigned long
-			     *state)
-{
-	struct acpi_device *device = cdev->devdata;
-	struct acpi_fan *fan = acpi_driver_data(device);
-
-	if (fan->acpi4)
-		*state = fan->fps_count - 1;
-	else
-		*state = 1;
-	return 0;
-}
-
-static int fan_get_state_acpi4(struct acpi_device *device, unsigned long *state)
-{
-	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
-	struct acpi_fan *fan = acpi_driver_data(device);
-	union acpi_object *obj;
-	acpi_status status;
-	int control, i;
-
-	status = acpi_evaluate_object(device->handle, "_FST", NULL, &buffer);
-	if (ACPI_FAILURE(status)) {
-		dev_err(&device->dev, "Get fan state failed\n");
-		return -ENODEV;
-	}
-
-	obj = buffer.pointer;
-	if (!obj || obj->type != ACPI_TYPE_PACKAGE ||
-	    obj->package.count != 3 ||
-	    obj->package.elements[1].type != ACPI_TYPE_INTEGER) {
-		dev_err(&device->dev, "Invalid _FST data\n");
-		status = -EINVAL;
-		goto err;
-	}
-
-	control = obj->package.elements[1].integer.value;
-	for (i = 0; i < fan->fps_count; i++) {
-		/*
-		 * When Fine Grain Control is set, return the state
-		 * corresponding to maximum fan->fps[i].control
-		 * value compared to the current speed. Here the
-		 * fan->fps[] is sorted array with increasing speed.
-		 */
-		if (fan->fif.fine_grain_ctrl && control < fan->fps[i].control) {
-			i = (i > 0) ? i - 1 : 0;
-			break;
-		} else if (control == fan->fps[i].control) {
-			break;
-		}
-	}
-	if (i == fan->fps_count) {
-		dev_dbg(&device->dev, "Invalid control value returned\n");
-		status = -EINVAL;
-		goto err;
-	}
-
-	*state = i;
-
-err:
-	kfree(obj);
-	return status;
-}
-
-static int fan_get_state(struct acpi_device *device, unsigned long *state)
-{
-	int result;
-	int acpi_state = ACPI_STATE_D0;
-
-	result = acpi_device_update_power(device, &acpi_state);
-	if (result)
-		return result;
-
-	*state = acpi_state == ACPI_STATE_D3_COLD
-			|| acpi_state == ACPI_STATE_D3_HOT ?
-		0 : (acpi_state == ACPI_STATE_D0 ? 1 : -1);
-	return 0;
-}
-
-static int fan_get_cur_state(struct thermal_cooling_device *cdev, unsigned long
-			     *state)
-{
-	struct acpi_device *device = cdev->devdata;
-	struct acpi_fan *fan = acpi_driver_data(device);
-
-	if (fan->acpi4)
-		return fan_get_state_acpi4(device, state);
-	else
-		return fan_get_state(device, state);
-}
-
-static int fan_set_state(struct acpi_device *device, unsigned long state)
-{
-	if (state != 0 && state != 1)
-		return -EINVAL;
-
-	return acpi_device_set_power(device,
-				     state ? ACPI_STATE_D0 : ACPI_STATE_D3_COLD);
-}
-
-static int fan_set_state_acpi4(struct acpi_device *device, unsigned long state)
-{
-	struct acpi_fan *fan = acpi_driver_data(device);
-	acpi_status status;
-
-	if (state >= fan->fps_count)
-		return -EINVAL;
-
-	status = acpi_execute_simple_method(device->handle, "_FSL",
-					    fan->fps[state].control);
-	if (ACPI_FAILURE(status)) {
-		dev_dbg(&device->dev, "Failed to set state by _FSL\n");
-		return -ENODEV;
-	}
-
-	return 0;
-}
-
-static int
-fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
-{
-	struct acpi_device *device = cdev->devdata;
-	struct acpi_fan *fan = acpi_driver_data(device);
-
-	if (fan->acpi4)
-		return fan_set_state_acpi4(device, state);
-	else
-		return fan_set_state(device, state);
-}
-
-static const struct thermal_cooling_device_ops fan_cooling_ops = {
-	.get_max_state = fan_get_max_state,
-	.get_cur_state = fan_get_cur_state,
-	.set_cur_state = fan_set_cur_state,
-};
-
-/* --------------------------------------------------------------------------
- *                               Driver Interface
- * --------------------------------------------------------------------------
-*/
-
-static bool acpi_fan_is_acpi4(struct acpi_device *device)
-{
-	return acpi_has_method(device->handle, "_FIF") &&
-	       acpi_has_method(device->handle, "_FPS") &&
-	       acpi_has_method(device->handle, "_FSL") &&
-	       acpi_has_method(device->handle, "_FST");
-}
-
-static int acpi_fan_get_fif(struct acpi_device *device)
-{
-	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
-	struct acpi_fan *fan = acpi_driver_data(device);
-	struct acpi_buffer format = { sizeof("NNNN"), "NNNN" };
-	struct acpi_buffer fif = { sizeof(fan->fif), &fan->fif };
-	union acpi_object *obj;
-	acpi_status status;
-
-	status = acpi_evaluate_object(device->handle, "_FIF", NULL, &buffer);
-	if (ACPI_FAILURE(status))
-		return status;
-
-	obj = buffer.pointer;
-	if (!obj || obj->type != ACPI_TYPE_PACKAGE) {
-		dev_err(&device->dev, "Invalid _FIF data\n");
-		status = -EINVAL;
-		goto err;
-	}
-
-	status = acpi_extract_package(obj, &format, &fif);
-	if (ACPI_FAILURE(status)) {
-		dev_err(&device->dev, "Invalid _FIF element\n");
-		status = -EINVAL;
-	}
-
-err:
-	kfree(obj);
-	return status;
-}
-
-static int acpi_fan_speed_cmp(const void *a, const void *b)
-{
-	const struct acpi_fan_fps *fps1 = a;
-	const struct acpi_fan_fps *fps2 = b;
-	return fps1->speed - fps2->speed;
-}
-
-static ssize_t show_state(struct device *dev, struct device_attribute *attr, char *buf)
-{
-	struct acpi_fan_fps *fps = container_of(attr, struct acpi_fan_fps, dev_attr);
-	int count;
-
-	if (fps->control == 0xFFFFFFFF || fps->control > 100)
-		count = scnprintf(buf, PAGE_SIZE, "not-defined:");
-	else
-		count = scnprintf(buf, PAGE_SIZE, "%lld:", fps->control);
-
-	if (fps->trip_point == 0xFFFFFFFF || fps->trip_point > 9)
-		count += scnprintf(&buf[count], PAGE_SIZE - count, "not-defined:");
-	else
-		count += scnprintf(&buf[count], PAGE_SIZE - count, "%lld:", fps->trip_point);
-
-	if (fps->speed == 0xFFFFFFFF)
-		count += scnprintf(&buf[count], PAGE_SIZE - count, "not-defined:");
-	else
-		count += scnprintf(&buf[count], PAGE_SIZE - count, "%lld:", fps->speed);
-
-	if (fps->noise_level == 0xFFFFFFFF)
-		count += scnprintf(&buf[count], PAGE_SIZE - count, "not-defined:");
-	else
-		count += scnprintf(&buf[count], PAGE_SIZE - count, "%lld:", fps->noise_level * 100);
-
-	if (fps->power == 0xFFFFFFFF)
-		count += scnprintf(&buf[count], PAGE_SIZE - count, "not-defined\n");
-	else
-		count += scnprintf(&buf[count], PAGE_SIZE - count, "%lld\n", fps->power);
-
-	return count;
-}
-
-static int acpi_fan_get_fps(struct acpi_device *device)
-{
-	struct acpi_fan *fan = acpi_driver_data(device);
-	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
-	union acpi_object *obj;
-	acpi_status status;
-	int i;
-
-	status = acpi_evaluate_object(device->handle, "_FPS", NULL, &buffer);
-	if (ACPI_FAILURE(status))
-		return status;
-
-	obj = buffer.pointer;
-	if (!obj || obj->type != ACPI_TYPE_PACKAGE || obj->package.count < 2) {
-		dev_err(&device->dev, "Invalid _FPS data\n");
-		status = -EINVAL;
-		goto err;
-	}
-
-	fan->fps_count = obj->package.count - 1; /* minus revision field */
-	fan->fps = devm_kcalloc(&device->dev,
-				fan->fps_count, sizeof(struct acpi_fan_fps),
-				GFP_KERNEL);
-	if (!fan->fps) {
-		dev_err(&device->dev, "Not enough memory\n");
-		status = -ENOMEM;
-		goto err;
-	}
-	for (i = 0; i < fan->fps_count; i++) {
-		struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
-		struct acpi_buffer fps = { offsetof(struct acpi_fan_fps, name),
-						&fan->fps[i] };
-		status = acpi_extract_package(&obj->package.elements[i + 1],
-					      &format, &fps);
-		if (ACPI_FAILURE(status)) {
-			dev_err(&device->dev, "Invalid _FPS element\n");
-			goto err;
-		}
-	}
-
-	/* sort the state array according to fan speed in increase order */
-	sort(fan->fps, fan->fps_count, sizeof(*fan->fps),
-	     acpi_fan_speed_cmp, NULL);
-
-	for (i = 0; i < fan->fps_count; ++i) {
-		struct acpi_fan_fps *fps = &fan->fps[i];
-
-		snprintf(fps->name, ACPI_FPS_NAME_LEN, "state%d", i);
-		sysfs_attr_init(&fps->dev_attr.attr);
-		fps->dev_attr.show = show_state;
-		fps->dev_attr.store = NULL;
-		fps->dev_attr.attr.name = fps->name;
-		fps->dev_attr.attr.mode = 0444;
-		status = sysfs_create_file(&device->dev.kobj, &fps->dev_attr.attr);
-		if (status) {
-			int j;
-
-			for (j = 0; j < i; ++j)
-				sysfs_remove_file(&device->dev.kobj, &fan->fps[j].dev_attr.attr);
-			break;
-		}
-	}
-
-err:
-	kfree(obj);
-	return status;
-}
-
-static int acpi_fan_probe(struct platform_device *pdev)
-{
-	int result = 0;
-	struct thermal_cooling_device *cdev;
-	struct acpi_fan *fan;
-	struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
-	char *name;
-
-	fan = devm_kzalloc(&pdev->dev, sizeof(*fan), GFP_KERNEL);
-	if (!fan) {
-		dev_err(&device->dev, "No memory for fan\n");
-		return -ENOMEM;
-	}
-	device->driver_data = fan;
-	platform_set_drvdata(pdev, fan);
-
-	if (acpi_fan_is_acpi4(device)) {
-		result = acpi_fan_get_fif(device);
-		if (result)
-			return result;
-
-		result = acpi_fan_get_fps(device);
-		if (result)
-			return result;
-
-		fan->acpi4 = true;
-	} else {
-		result = acpi_device_update_power(device, NULL);
-		if (result) {
-			dev_err(&device->dev, "Failed to set initial power state\n");
-			goto err_end;
-		}
-	}
-
-	if (!strncmp(pdev->name, "PNP0C0B", strlen("PNP0C0B")))
-		name = "Fan";
-	else
-		name = acpi_device_bid(device);
-
-	cdev = thermal_cooling_device_register(name, device,
-						&fan_cooling_ops);
-	if (IS_ERR(cdev)) {
-		result = PTR_ERR(cdev);
-		goto err_end;
-	}
-
-	dev_dbg(&pdev->dev, "registered as cooling_device%d\n", cdev->id);
-
-	fan->cdev = cdev;
-	result = sysfs_create_link(&pdev->dev.kobj,
-				   &cdev->device.kobj,
-				   "thermal_cooling");
-	if (result)
-		dev_err(&pdev->dev, "Failed to create sysfs link 'thermal_cooling'\n");
-
-	result = sysfs_create_link(&cdev->device.kobj,
-				   &pdev->dev.kobj,
-				   "device");
-	if (result) {
-		dev_err(&pdev->dev, "Failed to create sysfs link 'device'\n");
-		goto err_end;
-	}
-
-	return 0;
-
-err_end:
-	if (fan->acpi4) {
-		int i;
-
-		for (i = 0; i < fan->fps_count; ++i)
-			sysfs_remove_file(&device->dev.kobj, &fan->fps[i].dev_attr.attr);
-	}
-
-	return result;
-}
-
-static int acpi_fan_remove(struct platform_device *pdev)
-{
-	struct acpi_fan *fan = platform_get_drvdata(pdev);
-
-	if (fan->acpi4) {
-		struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
-		int i;
-
-		for (i = 0; i < fan->fps_count; ++i)
-			sysfs_remove_file(&device->dev.kobj, &fan->fps[i].dev_attr.attr);
-	}
-	sysfs_remove_link(&pdev->dev.kobj, "thermal_cooling");
-	sysfs_remove_link(&fan->cdev->device.kobj, "device");
-	thermal_cooling_device_unregister(fan->cdev);
-
-	return 0;
-}
-
-#ifdef CONFIG_PM_SLEEP
-static int acpi_fan_suspend(struct device *dev)
-{
-	struct acpi_fan *fan = dev_get_drvdata(dev);
-	if (fan->acpi4)
-		return 0;
-
-	acpi_device_set_power(ACPI_COMPANION(dev), ACPI_STATE_D0);
-
-	return AE_OK;
-}
-
-static int acpi_fan_resume(struct device *dev)
-{
-	int result;
-	struct acpi_fan *fan = dev_get_drvdata(dev);
-
-	if (fan->acpi4)
-		return 0;
-
-	result = acpi_device_update_power(ACPI_COMPANION(dev), NULL);
-	if (result)
-		dev_err(dev, "Error updating fan power state\n");
-
-	return result;
-}
-#endif
-
-module_platform_driver(acpi_fan_driver);
--- a/drivers/acpi/fan.h
+++ b/drivers/acpi/fan.h
@@ -6,9 +6,44 @@
  *
  * Add new device IDs before the generic ACPI fan one.
  */
+
+#ifndef _ACPI_FAN_H_
+#define _ACPI_FAN_H_
+
 #define ACPI_FAN_DEVICE_IDS	\
 	{"INT3404", }, /* Fan */ \
 	{"INTC1044", }, /* Fan for Tiger Lake generation */ \
 	{"INTC1048", }, /* Fan for Alder Lake generation */ \
 	{"INTC10A2", }, /* Fan for Raptor Lake generation */ \
 	{"PNP0C0B", } /* Generic ACPI fan */
+
+#define ACPI_FPS_NAME_LEN	20
+
+struct acpi_fan_fps {
+	u64 control;
+	u64 trip_point;
+	u64 speed;
+	u64 noise_level;
+	u64 power;
+	char name[ACPI_FPS_NAME_LEN];
+	struct device_attribute dev_attr;
+};
+
+struct acpi_fan_fif {
+	u64 revision;
+	u64 fine_grain_ctrl;
+	u64 step_size;
+	u64 low_speed_notification;
+};
+
+struct acpi_fan {
+	bool acpi4;
+	struct acpi_fan_fif fif;
+	struct acpi_fan_fps *fps;
+	int fps_count;
+	struct thermal_cooling_device *cdev;
+};
+
+int acpi_fan_create_attributes(struct acpi_device *device);
+void acpi_fan_delete_attributes(struct acpi_device *device);
+#endif
--- /dev/null
+++ b/drivers/acpi/fan_attr.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  fan_attr.c - Create extra attributes for ACPI Fan driver
+ *
+ *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *  Copyright (C) 2022 Intel Corporation. All rights reserved.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/acpi.h>
+
+#include "fan.h"
+
+MODULE_LICENSE("GPL");
+
+static ssize_t show_state(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct acpi_fan_fps *fps = container_of(attr, struct acpi_fan_fps, dev_attr);
+	int count;
+
+	if (fps->control == 0xFFFFFFFF || fps->control > 100)
+		count = scnprintf(buf, PAGE_SIZE, "not-defined:");
+	else
+		count = scnprintf(buf, PAGE_SIZE, "%lld:", fps->control);
+
+	if (fps->trip_point == 0xFFFFFFFF || fps->trip_point > 9)
+		count += scnprintf(&buf[count], PAGE_SIZE - count, "not-defined:");
+	else
+		count += scnprintf(&buf[count], PAGE_SIZE - count, "%lld:", fps->trip_point);
+
+	if (fps->speed == 0xFFFFFFFF)
+		count += scnprintf(&buf[count], PAGE_SIZE - count, "not-defined:");
+	else
+		count += scnprintf(&buf[count], PAGE_SIZE - count, "%lld:", fps->speed);
+
+	if (fps->noise_level == 0xFFFFFFFF)
+		count += scnprintf(&buf[count], PAGE_SIZE - count, "not-defined:");
+	else
+		count += scnprintf(&buf[count], PAGE_SIZE - count, "%lld:", fps->noise_level * 100);
+
+	if (fps->power == 0xFFFFFFFF)
+		count += scnprintf(&buf[count], PAGE_SIZE - count, "not-defined\n");
+	else
+		count += scnprintf(&buf[count], PAGE_SIZE - count, "%lld\n", fps->power);
+
+	return count;
+}
+
+int acpi_fan_create_attributes(struct acpi_device *device)
+{
+	struct acpi_fan *fan = acpi_driver_data(device);
+	int i, status = 0;
+
+	for (i = 0; i < fan->fps_count; ++i) {
+		struct acpi_fan_fps *fps = &fan->fps[i];
+
+		snprintf(fps->name, ACPI_FPS_NAME_LEN, "state%d", i);
+		sysfs_attr_init(&fps->dev_attr.attr);
+		fps->dev_attr.show = show_state;
+		fps->dev_attr.store = NULL;
+		fps->dev_attr.attr.name = fps->name;
+		fps->dev_attr.attr.mode = 0444;
+		status = sysfs_create_file(&device->dev.kobj, &fps->dev_attr.attr);
+		if (status) {
+			int j;
+
+			for (j = 0; j < i; ++j)
+				sysfs_remove_file(&device->dev.kobj, &fan->fps[j].dev_attr.attr);
+			break;
+		}
+	}
+
+	return status;
+}
+
+void acpi_fan_delete_attributes(struct acpi_device *device)
+{
+	struct acpi_fan *fan = acpi_driver_data(device);
+	int i;
+
+	for (i = 0; i < fan->fps_count; ++i)
+		sysfs_remove_file(&device->dev.kobj, &fan->fps[i].dev_attr.attr);
+}
--- /dev/null
+++ b/drivers/acpi/fan_core.c
@@ -0,0 +1,416 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  fan_core.c - ACPI Fan core Driver
+ *
+ *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *  Copyright (C) 2022 Intel Corporation. All rights reserved.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/thermal.h>
+#include <linux/acpi.h>
+#include <linux/platform_device.h>
+#include <linux/sort.h>
+
+#include "fan.h"
+
+MODULE_AUTHOR("Paul Diefenbaugh");
+MODULE_DESCRIPTION("ACPI Fan Driver");
+MODULE_LICENSE("GPL");
+
+static int acpi_fan_probe(struct platform_device *pdev);
+static int acpi_fan_remove(struct platform_device *pdev);
+
+static const struct acpi_device_id fan_device_ids[] = {
+	ACPI_FAN_DEVICE_IDS,
+	{"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, fan_device_ids);
+
+#ifdef CONFIG_PM_SLEEP
+static int acpi_fan_suspend(struct device *dev);
+static int acpi_fan_resume(struct device *dev);
+static const struct dev_pm_ops acpi_fan_pm = {
+	.resume = acpi_fan_resume,
+	.freeze = acpi_fan_suspend,
+	.thaw = acpi_fan_resume,
+	.restore = acpi_fan_resume,
+};
+#define FAN_PM_OPS_PTR (&acpi_fan_pm)
+#else
+#define FAN_PM_OPS_PTR NULL
+#endif
+
+static struct platform_driver acpi_fan_driver = {
+	.probe = acpi_fan_probe,
+	.remove = acpi_fan_remove,
+	.driver = {
+		.name = "acpi-fan",
+		.acpi_match_table = fan_device_ids,
+		.pm = FAN_PM_OPS_PTR,
+	},
+};
+
+/* thermal cooling device callbacks */
+static int fan_get_max_state(struct thermal_cooling_device *cdev, unsigned long
+			     *state)
+{
+	struct acpi_device *device = cdev->devdata;
+	struct acpi_fan *fan = acpi_driver_data(device);
+
+	if (fan->acpi4)
+		*state = fan->fps_count - 1;
+	else
+		*state = 1;
+	return 0;
+}
+
+static int fan_get_state_acpi4(struct acpi_device *device, unsigned long *state)
+{
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	struct acpi_fan *fan = acpi_driver_data(device);
+	union acpi_object *obj;
+	acpi_status status;
+	int control, i;
+
+	status = acpi_evaluate_object(device->handle, "_FST", NULL, &buffer);
+	if (ACPI_FAILURE(status)) {
+		dev_err(&device->dev, "Get fan state failed\n");
+		return -ENODEV;
+	}
+
+	obj = buffer.pointer;
+	if (!obj || obj->type != ACPI_TYPE_PACKAGE ||
+	    obj->package.count != 3 ||
+	    obj->package.elements[1].type != ACPI_TYPE_INTEGER) {
+		dev_err(&device->dev, "Invalid _FST data\n");
+		status = -EINVAL;
+		goto err;
+	}
+
+	control = obj->package.elements[1].integer.value;
+	for (i = 0; i < fan->fps_count; i++) {
+		/*
+		 * When Fine Grain Control is set, return the state
+		 * corresponding to maximum fan->fps[i].control
+		 * value compared to the current speed. Here the
+		 * fan->fps[] is sorted array with increasing speed.
+		 */
+		if (fan->fif.fine_grain_ctrl && control < fan->fps[i].control) {
+			i = (i > 0) ? i - 1 : 0;
+			break;
+		} else if (control == fan->fps[i].control) {
+			break;
+		}
+	}
+	if (i == fan->fps_count) {
+		dev_dbg(&device->dev, "Invalid control value returned\n");
+		status = -EINVAL;
+		goto err;
+	}
+
+	*state = i;
+
+err:
+	kfree(obj);
+	return status;
+}
+
+static int fan_get_state(struct acpi_device *device, unsigned long *state)
+{
+	int result;
+	int acpi_state = ACPI_STATE_D0;
+
+	result = acpi_device_update_power(device, &acpi_state);
+	if (result)
+		return result;
+
+	*state = acpi_state == ACPI_STATE_D3_COLD
+			|| acpi_state == ACPI_STATE_D3_HOT ?
+		0 : (acpi_state == ACPI_STATE_D0 ? 1 : -1);
+	return 0;
+}
+
+static int fan_get_cur_state(struct thermal_cooling_device *cdev, unsigned long
+			     *state)
+{
+	struct acpi_device *device = cdev->devdata;
+	struct acpi_fan *fan = acpi_driver_data(device);
+
+	if (fan->acpi4)
+		return fan_get_state_acpi4(device, state);
+	else
+		return fan_get_state(device, state);
+}
+
+static int fan_set_state(struct acpi_device *device, unsigned long state)
+{
+	if (state != 0 && state != 1)
+		return -EINVAL;
+
+	return acpi_device_set_power(device,
+				     state ? ACPI_STATE_D0 : ACPI_STATE_D3_COLD);
+}
+
+static int fan_set_state_acpi4(struct acpi_device *device, unsigned long state)
+{
+	struct acpi_fan *fan = acpi_driver_data(device);
+	acpi_status status;
+
+	if (state >= fan->fps_count)
+		return -EINVAL;
+
+	status = acpi_execute_simple_method(device->handle, "_FSL",
+					    fan->fps[state].control);
+	if (ACPI_FAILURE(status)) {
+		dev_dbg(&device->dev, "Failed to set state by _FSL\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int
+fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
+{
+	struct acpi_device *device = cdev->devdata;
+	struct acpi_fan *fan = acpi_driver_data(device);
+
+	if (fan->acpi4)
+		return fan_set_state_acpi4(device, state);
+	else
+		return fan_set_state(device, state);
+}
+
+static const struct thermal_cooling_device_ops fan_cooling_ops = {
+	.get_max_state = fan_get_max_state,
+	.get_cur_state = fan_get_cur_state,
+	.set_cur_state = fan_set_cur_state,
+};
+
+/* --------------------------------------------------------------------------
+ *                               Driver Interface
+ * --------------------------------------------------------------------------
+*/
+
+static bool acpi_fan_is_acpi4(struct acpi_device *device)
+{
+	return acpi_has_method(device->handle, "_FIF") &&
+	       acpi_has_method(device->handle, "_FPS") &&
+	       acpi_has_method(device->handle, "_FSL") &&
+	       acpi_has_method(device->handle, "_FST");
+}
+
+static int acpi_fan_get_fif(struct acpi_device *device)
+{
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	struct acpi_fan *fan = acpi_driver_data(device);
+	struct acpi_buffer format = { sizeof("NNNN"), "NNNN" };
+	struct acpi_buffer fif = { sizeof(fan->fif), &fan->fif };
+	union acpi_object *obj;
+	acpi_status status;
+
+	status = acpi_evaluate_object(device->handle, "_FIF", NULL, &buffer);
+	if (ACPI_FAILURE(status))
+		return status;
+
+	obj = buffer.pointer;
+	if (!obj || obj->type != ACPI_TYPE_PACKAGE) {
+		dev_err(&device->dev, "Invalid _FIF data\n");
+		status = -EINVAL;
+		goto err;
+	}
+
+	status = acpi_extract_package(obj, &format, &fif);
+	if (ACPI_FAILURE(status)) {
+		dev_err(&device->dev, "Invalid _FIF element\n");
+		status = -EINVAL;
+	}
+
+err:
+	kfree(obj);
+	return status;
+}
+
+static int acpi_fan_speed_cmp(const void *a, const void *b)
+{
+	const struct acpi_fan_fps *fps1 = a;
+	const struct acpi_fan_fps *fps2 = b;
+	return fps1->speed - fps2->speed;
+}
+
+static int acpi_fan_get_fps(struct acpi_device *device)
+{
+	struct acpi_fan *fan = acpi_driver_data(device);
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *obj;
+	acpi_status status;
+	int i;
+
+	status = acpi_evaluate_object(device->handle, "_FPS", NULL, &buffer);
+	if (ACPI_FAILURE(status))
+		return status;
+
+	obj = buffer.pointer;
+	if (!obj || obj->type != ACPI_TYPE_PACKAGE || obj->package.count < 2) {
+		dev_err(&device->dev, "Invalid _FPS data\n");
+		status = -EINVAL;
+		goto err;
+	}
+
+	fan->fps_count = obj->package.count - 1; /* minus revision field */
+	fan->fps = devm_kcalloc(&device->dev,
+				fan->fps_count, sizeof(struct acpi_fan_fps),
+				GFP_KERNEL);
+	if (!fan->fps) {
+		dev_err(&device->dev, "Not enough memory\n");
+		status = -ENOMEM;
+		goto err;
+	}
+	for (i = 0; i < fan->fps_count; i++) {
+		struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
+		struct acpi_buffer fps = { offsetof(struct acpi_fan_fps, name),
+						&fan->fps[i] };
+		status = acpi_extract_package(&obj->package.elements[i + 1],
+					      &format, &fps);
+		if (ACPI_FAILURE(status)) {
+			dev_err(&device->dev, "Invalid _FPS element\n");
+			goto err;
+		}
+	}
+
+	/* sort the state array according to fan speed in increase order */
+	sort(fan->fps, fan->fps_count, sizeof(*fan->fps),
+	     acpi_fan_speed_cmp, NULL);
+
+err:
+	kfree(obj);
+	return status;
+}
+
+static int acpi_fan_probe(struct platform_device *pdev)
+{
+	int result = 0;
+	struct thermal_cooling_device *cdev;
+	struct acpi_fan *fan;
+	struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
+	char *name;
+
+	fan = devm_kzalloc(&pdev->dev, sizeof(*fan), GFP_KERNEL);
+	if (!fan) {
+		dev_err(&device->dev, "No memory for fan\n");
+		return -ENOMEM;
+	}
+	device->driver_data = fan;
+	platform_set_drvdata(pdev, fan);
+
+	if (acpi_fan_is_acpi4(device)) {
+		result = acpi_fan_get_fif(device);
+		if (result)
+			return result;
+
+		result = acpi_fan_get_fps(device);
+		if (result)
+			return result;
+
+		result = acpi_fan_create_attributes(device);
+		if (result)
+			return result;
+
+		fan->acpi4 = true;
+	} else {
+		result = acpi_device_update_power(device, NULL);
+		if (result) {
+			dev_err(&device->dev, "Failed to set initial power state\n");
+			goto err_end;
+		}
+	}
+
+	if (!strncmp(pdev->name, "PNP0C0B", strlen("PNP0C0B")))
+		name = "Fan";
+	else
+		name = acpi_device_bid(device);
+
+	cdev = thermal_cooling_device_register(name, device,
+						&fan_cooling_ops);
+	if (IS_ERR(cdev)) {
+		result = PTR_ERR(cdev);
+		goto err_end;
+	}
+
+	dev_dbg(&pdev->dev, "registered as cooling_device%d\n", cdev->id);
+
+	fan->cdev = cdev;
+	result = sysfs_create_link(&pdev->dev.kobj,
+				   &cdev->device.kobj,
+				   "thermal_cooling");
+	if (result)
+		dev_err(&pdev->dev, "Failed to create sysfs link 'thermal_cooling'\n");
+
+	result = sysfs_create_link(&cdev->device.kobj,
+				   &pdev->dev.kobj,
+				   "device");
+	if (result) {
+		dev_err(&pdev->dev, "Failed to create sysfs link 'device'\n");
+		goto err_end;
+	}
+
+	return 0;
+
+err_end:
+	if (fan->acpi4)
+		acpi_fan_delete_attributes(device);
+
+	return result;
+}
+
+static int acpi_fan_remove(struct platform_device *pdev)
+{
+	struct acpi_fan *fan = platform_get_drvdata(pdev);
+
+	if (fan->acpi4) {
+		struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
+
+		acpi_fan_delete_attributes(device);
+	}
+	sysfs_remove_link(&pdev->dev.kobj, "thermal_cooling");
+	sysfs_remove_link(&fan->cdev->device.kobj, "device");
+	thermal_cooling_device_unregister(fan->cdev);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int acpi_fan_suspend(struct device *dev)
+{
+	struct acpi_fan *fan = dev_get_drvdata(dev);
+	if (fan->acpi4)
+		return 0;
+
+	acpi_device_set_power(ACPI_COMPANION(dev), ACPI_STATE_D0);
+
+	return AE_OK;
+}
+
+static int acpi_fan_resume(struct device *dev)
+{
+	int result;
+	struct acpi_fan *fan = dev_get_drvdata(dev);
+
+	if (fan->acpi4)
+		return 0;
+
+	result = acpi_device_update_power(ACPI_COMPANION(dev), NULL);
+	if (result)
+		dev_err(dev, "Error updating fan power state\n");
+
+	return result;
+}
+#endif
+
+module_platform_driver(acpi_fan_driver);