alistair23-linux/drivers/acpi/fan.c
Rafael J. Wysocki 20dacb71ad ACPI / PM: Rework device power management to follow ACPI 6
The ACPI 6 specification has made some changes in the device power
management area.  In particular:

 * The D3hot power state is now supposed to be always available
   (instead of D3cold) and D3cold is only regarded as valid if the
   _PR3 object is present for the given device.

 * The required ordering of transitions into power states deeper than
   D0 is now such that for a transition into state Dx the _PSx method
   is supposed to be executed first, if present, and the states of
   the power resources the device depends on are supposed to be
   changed after that.

 * It is now explicitly forbidden to transition devices from
   lower-power (deeper) into higher-power (shallower) power states
   other than D0.

Those changes have been made so the specification reflects the
Windows' device power management code that the vast majority of
systems using ACPI is validated against.

To avoid artificial differences in ACPI device power management
between Windows and Linux, modify the ACPI device power management
code to follow the new specification.  Add comments explaining the
code flow in some unclear places.

This only may affect some real corner cases in which the OS behavior
expected by the firmware is different from the Windows one, but that's
quite unlikely.  The transition ordering change affects transitions
to D1 and D2 which are rarely used (if at all) and into D3hot and
D3cold for devices actually having _PR3, but those are likely to
be validated against Windows anyway.  The other changes may affect
code calling acpi_device_get_power() or acpi_device_update_power()
where ACPI_STATE_D3_HOT may be returned instead of ACPI_STATE_D3_COLD
(that's why the ACPI fan driver needs to be updated too) and since
transitions into ACPI_STATE_D3_HOT may remove power now, it is better
to avoid this one in acpi_pm_device_sleep_state() if the "no power
off" PM QoS flag is set.

The only existing user of acpi_device_can_poweroff() really cares
about the case when _PR3 is present, so the change in that function
should not cause any problems to happen too.

A plus is that PCI_D3hot can be mapped to ACPI_STATE_D3_HOT
now and the compatibility with older systems should be covered
automatically.

In any case, if any real problems result from this, it still will
be better to follow the Windows' behavior (which now is reflected
by the specification too) in general and handle the cases when it
doesn't work via quirks.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-05-16 01:55:35 +02:00

422 lines
10 KiB
C

/*
* 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>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#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>
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[] = {
{"PNP0C0B", 0},
{"INT3404", 0},
{"", 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 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
struct acpi_fan_fps {
u64 control;
u64 trip_point;
u64 speed;
u64 noise_level;
u64 power;
};
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 status;
}
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++) {
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 status;
}
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_kzalloc(&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 = { sizeof(fan->fps[i]), &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");
break;
}
}
/* 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)) {
if (acpi_fan_get_fif(device) || acpi_fan_get_fps(device))
goto end;
fan->acpi4 = true;
} else {
result = acpi_device_update_power(device, NULL);
if (result) {
dev_err(&device->dev, "Setting initial power state\n");
goto 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 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");
end:
return result;
}
static int acpi_fan_remove(struct platform_device *pdev)
{
struct acpi_fan *fan = platform_get_drvdata(pdev);
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);