linux/drivers/acpi/fan_core.c
Srinivas Pandruvada f1197343f0 ACPI: fan: Add additional attributes for fine grain control
Add additional attributes, which helps in implementing algorithm in
the user space to optimize fan control. These attributes are presented
in the same directory as the existing performance state attributes.

Additional attributes:

1. Support of fine grain control
Publish support of presence of fine grain control so that fan speed
can be tuned correctly. This attribute is called "fine_grain_control".

2. fan speed
Publish the actual fan rpm in sysfs. Knowing fan rpm is helpful to
reduce noise level and use passive control instead. Also fan performance
may not be same over time, so the same control value may not be enough
to run the fan at a speed. So a feedback value of speed is helpful. This
sysfs attribute is called "fan_speed_rpm".

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-02-25 20:49:30 +01:00

465 lines
11 KiB
C

// 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) {
if (fan->fif.fine_grain_ctrl)
*state = 100 / fan->fif.step_size;
else
*state = fan->fps_count - 1;
} else {
*state = 1;
}
return 0;
}
int acpi_fan_get_fst(struct acpi_device *device, struct acpi_fan_fst *fst)
{
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
union acpi_object *obj;
acpi_status status;
int ret = 0;
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");
ret = -EINVAL;
goto err;
}
fst->revision = obj->package.elements[0].integer.value;
fst->control = obj->package.elements[1].integer.value;
fst->speed = obj->package.elements[2].integer.value;
err:
kfree(obj);
return ret;
}
static int fan_get_state_acpi4(struct acpi_device *device, unsigned long *state)
{
struct acpi_fan *fan = acpi_driver_data(device);
struct acpi_fan_fst fst;
int status, i;
status = acpi_fan_get_fst(device, &fst);
if (status)
return status;
if (fan->fif.fine_grain_ctrl) {
/* This control should be same what we set using _FSL by spec */
if (fst.control > 100) {
dev_dbg(&device->dev, "Invalid control value returned\n");
goto match_fps;
}
*state = (int) fst.control / fan->fif.step_size;
return 0;
}
match_fps:
for (i = 0; i < fan->fps_count; i++) {
if (fst.control == fan->fps[i].control)
break;
}
if (i == fan->fps_count) {
dev_dbg(&device->dev, "Invalid control value returned\n");
return -EINVAL;
}
*state = i;
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;
u64 value = state;
int max_state;
if (fan->fif.fine_grain_ctrl)
max_state = 100 / fan->fif.step_size;
else
max_state = fan->fps_count - 1;
if (state > max_state)
return -EINVAL;
if (fan->fif.fine_grain_ctrl) {
value *= fan->fif.step_size;
/* Spec allows compensate the last step only */
if (value + fan->fif.step_size > 100)
value = 100;
} else {
value = fan->fps[state].control;
}
status = acpi_execute_simple_method(device->handle, "_FSL", value);
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" };
u64 fields[4];
struct acpi_buffer fif = { sizeof(fields), fields };
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;
}
fan->fif.revision = fields[0];
fan->fif.fine_grain_ctrl = fields[1];
fan->fif.step_size = fields[2];
fan->fif.low_speed_notification = fields[3];
/* If there is a bug in step size and set as 0, change to 1 */
if (!fan->fif.step_size)
fan->fif.step_size = 1;
/* If step size > 9, change to 9 (by spec valid values 1-9) */
else if (fan->fif.step_size > 9)
fan->fif.step_size = 9;
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);