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_lpss_chip *lpwm;
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	lpwm = devm_pwm_lpss_probe(&pdev->dev, base, info);
35	if (IS_ERR(lpwm))
36		return PTR_ERR(lpwm);
37
38	platform_set_drvdata(pdev, lpwm);
39
40	/*
41	 * On Cherry Trail devices the GFX0._PS0 AML checks if the controller
42	 * is on and if it is not on it turns it on and restores what it
43	 * believes is the correct state to the PWM controller.
44	 * Because of this we must disallow direct-complete, which keeps the
45	 * controller (runtime)suspended on resume, to avoid 2 issues:
46	 * 1. The controller getting turned on without the linux-pm code
47	 *    knowing about this. On devices where the controller is unused
48	 *    this causes it to stay on during the next suspend causing high
49	 *    battery drain (because S0i3 is not reached)
50	 * 2. The state restoring code unexpectedly messing with the controller
51	 *
52	 * Leaving the controller runtime-suspended (skipping runtime-resume +
53	 * normal-suspend) during suspend is fine.
54	 */
55	if (info->other_devices_aml_touches_pwm_regs)
56		dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE|
57						    DPM_FLAG_SMART_SUSPEND);
58
59	pm_runtime_set_active(&pdev->dev);
60	pm_runtime_enable(&pdev->dev);
61
62	return 0;
63}
64
65static void pwm_lpss_remove_platform(struct platform_device *pdev)
66{
67	pm_runtime_disable(&pdev->dev);
68}
69
70static const struct acpi_device_id pwm_lpss_acpi_match[] = {
71	{ "80860F09", (unsigned long)&pwm_lpss_byt_info },
72	{ "80862288", (unsigned long)&pwm_lpss_bsw_info },
73	{ "80862289", (unsigned long)&pwm_lpss_bsw_info },
74	{ "80865AC8", (unsigned long)&pwm_lpss_bxt_info },
75	{ },
76};
77MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match);
78
79static struct platform_driver pwm_lpss_driver_platform = {
80	.driver = {
81		.name = "pwm-lpss",
82		.acpi_match_table = pwm_lpss_acpi_match,
83	},
84	.probe = pwm_lpss_probe_platform,
85	.remove_new = pwm_lpss_remove_platform,
86};
87module_platform_driver(pwm_lpss_driver_platform);
88
89MODULE_DESCRIPTION("PWM platform driver for Intel LPSS");
90MODULE_LICENSE("GPL v2");
91MODULE_IMPORT_NS(PWM_LPSS);
92MODULE_ALIAS("platform:pwm-lpss");