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(dev: &pdev->dev);
27 if (!info)
28 return -ENODEV;
29
30 base = devm_platform_ioremap_resource(pdev, index: 0);
31 if (IS_ERR(ptr: base))
32 return PTR_ERR(ptr: base);
33
34 chip = devm_pwm_lpss_probe(dev: &pdev->dev, base, info);
35 if (IS_ERR(ptr: chip))
36 return PTR_ERR(ptr: 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(dev: &pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE|
55 DPM_FLAG_SMART_SUSPEND);
56
57 pm_runtime_set_active(dev: &pdev->dev);
58 pm_runtime_enable(dev: &pdev->dev);
59
60 return 0;
61}
62
63static void pwm_lpss_remove_platform(struct platform_device *pdev)
64{
65 pm_runtime_disable(dev: &pdev->dev);
66}
67
68static 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 },
71 { "80862289", (unsigned long)&pwm_lpss_bsw_info },
72 { "80865AC8", (unsigned long)&pwm_lpss_bxt_info },
73 { },
74};
75MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match);
76
77static 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,
83 .remove_new = pwm_lpss_remove_platform,
84};
85module_platform_driver(pwm_lpss_driver_platform);
86
87MODULE_DESCRIPTION("PWM platform driver for Intel LPSS");
88MODULE_LICENSE("GPL v2");
89MODULE_IMPORT_NS(PWM_LPSS);
90MODULE_ALIAS("platform:pwm-lpss");
91

source code of linux/drivers/pwm/pwm-lpss-platform.c