1// SPDX-License-Identifier: GPL-2.0-only
 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
 8 */
 9
10#include <linux/kernel.h>
11#include <linux/mod_devicetable.h>
12#include <linux/module.h>
13#include <linux/platform_device.h>
14#include <linux/pm_runtime.h>
15#include <linux/property.h>
16
17#include "pwm-lpss.h"
18
19
20static int pwm_lpss_probe_platform(struct platform_device *pdev)
21{
22	const struct pwm_lpss_boardinfo *info;
23	struct pwm_chip *chip;
24	void __iomem *base;
25
26	info = device_get_match_data(&pdev->dev);
27	if (!info)
28		return -ENODEV;
29
30	base = devm_platform_ioremap_resource(pdev, 0);
31	if (IS_ERR(base))
32		return PTR_ERR(base);
33
34	chip = devm_pwm_lpss_probe(&pdev->dev, base, info);
35	if (IS_ERR(chip))
36		return PTR_ERR(chip);
37
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
49	 *
50	 * Leaving the controller runtime-suspended (skipping runtime-resume +
51	 * normal-suspend) during suspend is fine.
52	 */
53	if (info->other_devices_aml_touches_pwm_regs)
54		dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE|
55						    DPM_FLAG_SMART_SUSPEND);
56
57	pm_runtime_set_active(&pdev->dev);
58	return devm_pm_runtime_enable(&pdev->dev);
59}
60
61static const struct acpi_device_id pwm_lpss_acpi_match[] = {
62	{ "80860F09", (unsigned long)&pwm_lpss_byt_info },
63	{ "80862288", (unsigned long)&pwm_lpss_bsw_info },
64	{ "80862289", (unsigned long)&pwm_lpss_bsw_info },
65	{ "80865AC8", (unsigned long)&pwm_lpss_bxt_info },
66	{ },
67};
68MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match);
69
70static struct platform_driver pwm_lpss_driver_platform = {
71	.driver = {
72		.name = "pwm-lpss",
73		.acpi_match_table = pwm_lpss_acpi_match,
74	},
75	.probe = pwm_lpss_probe_platform,
76};
77module_platform_driver(pwm_lpss_driver_platform);
78
79MODULE_DESCRIPTION("PWM platform driver for Intel LPSS");
80MODULE_LICENSE("GPL v2");
81MODULE_IMPORT_NS("PWM_LPSS");
82MODULE_ALIAS("platform:pwm-lpss");