mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 17:30:02 +00:00
e3aa45f2f8
As the comment above the code setting the DPM_FLAG_NO_DIRECT_COMPLETE
flag explains:
/*
* On Cherry Trail devices the GFX0._PS0 AML checks if the controller
* is on and if it is not on it turns it on and restores what it
* believes is the correct state to the PWM controller.
* Because of this we must disallow direct-complete, which keeps the
* controller (runtime)suspended, on resume to avoid 2 issues:
* 1. The controller getting turned on without the linux-pm code
* knowing about this. On devices where the controller is unused
* this causes it to stay on during the next suspend causing high
* battery drain (because S0i3 is not reached)
* 2. The state restoring code unexpectedly messing with the controller
*/
The pm-core must not skip resume to avoid the GFX0._PS0 AML code messing
with the PWM controller behind our back. But leaving the controller
runtime-suspended (skipping runtime-resume + normal-suspend) during
suspend is fine. Set the DPM_FLAG_SMART_SUSPEND flag to allow this.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
115 lines
3.2 KiB
C
115 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Intel Low Power Subsystem PWM controller driver
|
|
*
|
|
* Copyright (C) 2014, Intel Corporation
|
|
*
|
|
* Derived from the original pwm-lpss.c
|
|
*/
|
|
|
|
#include <linux/acpi.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/pm_runtime.h>
|
|
|
|
#include "pwm-lpss.h"
|
|
|
|
/* BayTrail */
|
|
static const struct pwm_lpss_boardinfo pwm_lpss_byt_info = {
|
|
.clk_rate = 25000000,
|
|
.npwm = 1,
|
|
.base_unit_bits = 16,
|
|
};
|
|
|
|
/* Braswell */
|
|
static const struct pwm_lpss_boardinfo pwm_lpss_bsw_info = {
|
|
.clk_rate = 19200000,
|
|
.npwm = 1,
|
|
.base_unit_bits = 16,
|
|
.other_devices_aml_touches_pwm_regs = true,
|
|
};
|
|
|
|
/* Broxton */
|
|
static const struct pwm_lpss_boardinfo pwm_lpss_bxt_info = {
|
|
.clk_rate = 19200000,
|
|
.npwm = 4,
|
|
.base_unit_bits = 22,
|
|
.bypass = true,
|
|
};
|
|
|
|
static int pwm_lpss_probe_platform(struct platform_device *pdev)
|
|
{
|
|
const struct pwm_lpss_boardinfo *info;
|
|
const struct acpi_device_id *id;
|
|
struct pwm_lpss_chip *lpwm;
|
|
struct resource *r;
|
|
|
|
id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
|
|
if (!id)
|
|
return -ENODEV;
|
|
|
|
info = (const struct pwm_lpss_boardinfo *)id->driver_data;
|
|
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
|
|
lpwm = pwm_lpss_probe(&pdev->dev, r, info);
|
|
if (IS_ERR(lpwm))
|
|
return PTR_ERR(lpwm);
|
|
|
|
platform_set_drvdata(pdev, lpwm);
|
|
|
|
/*
|
|
* On Cherry Trail devices the GFX0._PS0 AML checks if the controller
|
|
* is on and if it is not on it turns it on and restores what it
|
|
* believes is the correct state to the PWM controller.
|
|
* Because of this we must disallow direct-complete, which keeps the
|
|
* controller (runtime)suspended on resume, to avoid 2 issues:
|
|
* 1. The controller getting turned on without the linux-pm code
|
|
* knowing about this. On devices where the controller is unused
|
|
* this causes it to stay on during the next suspend causing high
|
|
* battery drain (because S0i3 is not reached)
|
|
* 2. The state restoring code unexpectedly messing with the controller
|
|
*
|
|
* Leaving the controller runtime-suspended (skipping runtime-resume +
|
|
* normal-suspend) during suspend is fine.
|
|
*/
|
|
if (info->other_devices_aml_touches_pwm_regs)
|
|
dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE|
|
|
DPM_FLAG_SMART_SUSPEND);
|
|
|
|
pm_runtime_set_active(&pdev->dev);
|
|
pm_runtime_enable(&pdev->dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pwm_lpss_remove_platform(struct platform_device *pdev)
|
|
{
|
|
struct pwm_lpss_chip *lpwm = platform_get_drvdata(pdev);
|
|
|
|
pm_runtime_disable(&pdev->dev);
|
|
return pwm_lpss_remove(lpwm);
|
|
}
|
|
|
|
static const struct acpi_device_id pwm_lpss_acpi_match[] = {
|
|
{ "80860F09", (unsigned long)&pwm_lpss_byt_info },
|
|
{ "80862288", (unsigned long)&pwm_lpss_bsw_info },
|
|
{ "80862289", (unsigned long)&pwm_lpss_bsw_info },
|
|
{ "80865AC8", (unsigned long)&pwm_lpss_bxt_info },
|
|
{ },
|
|
};
|
|
MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match);
|
|
|
|
static struct platform_driver pwm_lpss_driver_platform = {
|
|
.driver = {
|
|
.name = "pwm-lpss",
|
|
.acpi_match_table = pwm_lpss_acpi_match,
|
|
},
|
|
.probe = pwm_lpss_probe_platform,
|
|
.remove = pwm_lpss_remove_platform,
|
|
};
|
|
module_platform_driver(pwm_lpss_driver_platform);
|
|
|
|
MODULE_DESCRIPTION("PWM platform driver for Intel LPSS");
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_ALIAS("platform:pwm-lpss");
|