[linux-block.git] / drivers / pwm / pwm-lpss-platform.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/kernel.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/property.h>

#include "pwm-lpss.h"


static int pwm_lpss_probe_platform(struct platform_device *pdev)
{
	const struct pwm_lpss_boardinfo *info;
	struct pwm_chip *chip;
	void __iomem *base;

	info = device_get_match_data(&pdev->dev);
	if (!info)
		return -ENODEV;

	base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(base))
		return PTR_ERR(base);

	chip = devm_pwm_lpss_probe(&pdev->dev, base, info);
	if (IS_ERR(chip))
		return PTR_ERR(chip);

	/*
	 * 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 void pwm_lpss_remove_platform(struct platform_device *pdev)
{
	pm_runtime_disable(&pdev->dev);
}

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_new = pwm_lpss_remove_platform,
};
module_platform_driver(pwm_lpss_driver_platform);

MODULE_DESCRIPTION("PWM platform driver for Intel LPSS");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS(PWM_LPSS);
MODULE_ALIAS("platform:pwm-lpss");
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
c558e39e AS	2	/*
	3	* Intel Low Power Subsystem PWM controller driver
	4	*
	5	* Copyright (C) 2014, Intel Corporation
	6	*
	7	* Derived from the original pwm-lpss.c
c558e39e AS	8	*/
c558e39e AS	9
c558e39e	10	#include <linux/kernel.h>
7f8dd161	11	#include <linux/mod_devicetable.h>
c558e39e AS	12	#include <linux/module.h>
c558e39e AS	13	#include <linux/platform_device.h>
f080be27	14	#include <linux/pm_runtime.h>
7f8dd161	15	#include <linux/property.h>
c558e39e AS	16
	17	#include "pwm-lpss.h"
	18
9900073c	19
c558e39e AS	20	static int pwm_lpss_probe_platform(struct platform_device *pdev)
	21	{
	22	const struct pwm_lpss_boardinfo *info;
05013062	23	struct pwm_chip *chip;
68af6fb0	24	void __iomem *base;
c558e39e	25
7f8dd161 AS	26	info = device_get_match_data(&pdev->dev);
7f8dd161 AS	27	if (!info)
c558e39e AS	28	return -ENODEV;
c558e39e AS	29
68af6fb0 AS	30	base = devm_platform_ioremap_resource(pdev, 0);
	31	if (IS_ERR(base))
	32	return PTR_ERR(base);
	33
05013062 UKK	34	chip = devm_pwm_lpss_probe(&pdev->dev, base, info);
	35	if (IS_ERR(chip))
	36	return PTR_ERR(chip);
c558e39e	37
b9c90f15 HG	38	/*
	39	* On Cherry Trail devices the GFX0._PS0 AML checks if the controller
	40	* is on and if it is not on it turns it on and restores what it
	41	* believes is the correct state to the PWM controller.
	42	* Because of this we must disallow direct-complete, which keeps the
	43	* controller (runtime)suspended on resume, to avoid 2 issues:
	44	* 1. The controller getting turned on without the linux-pm code
	45	* knowing about this. On devices where the controller is unused
	46	* this causes it to stay on during the next suspend causing high
	47	* battery drain (because S0i3 is not reached)
	48	* 2. The state restoring code unexpectedly messing with the controller
e3aa45f2 HG	49	*
	50	* Leaving the controller runtime-suspended (skipping runtime-resume +
	51	* normal-suspend) during suspend is fine.
b9c90f15 HG	52	*/
b9c90f15 HG	53	if (info->other_devices_aml_touches_pwm_regs)
e3aa45f2 HG	54	dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE\|
e3aa45f2 HG	55	DPM_FLAG_SMART_SUSPEND);
b9c90f15	56
f080be27 QZ	57	pm_runtime_set_active(&pdev->dev);
	58	pm_runtime_enable(&pdev->dev);
	59
c558e39e AS	60	return 0;
	61	}
	62
9a9174ea	63	static void pwm_lpss_remove_platform(struct platform_device *pdev)
c558e39e	64	{
f080be27	65	pm_runtime_disable(&pdev->dev);
c558e39e AS	66	}
	67
	68	static const struct acpi_device_id pwm_lpss_acpi_match[] = {
	69	{ "80860F09", (unsigned long)&pwm_lpss_byt_info },
	70	{ "80862288", (unsigned long)&pwm_lpss_bsw_info },
1688c871	71	{ "80862289", (unsigned long)&pwm_lpss_bsw_info },
03f00e53	72	{ "80865AC8", (unsigned long)&pwm_lpss_bxt_info },
c558e39e AS	73	{ },
	74	};
	75	MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match);
	76
	77	static struct platform_driver pwm_lpss_driver_platform = {
	78	.driver = {
	79	.name = "pwm-lpss",
	80	.acpi_match_table = pwm_lpss_acpi_match,
	81	},
	82	.probe = pwm_lpss_probe_platform,
9a9174ea	83	.remove_new = pwm_lpss_remove_platform,
c558e39e AS	84	};
	85	module_platform_driver(pwm_lpss_driver_platform);
	86
	87	MODULE_DESCRIPTION("PWM platform driver for Intel LPSS");
	88	MODULE_LICENSE("GPL v2");
a3682d2f	89	MODULE_IMPORT_NS(PWM_LPSS);
c558e39e	90	MODULE_ALIAS("platform:pwm-lpss");