tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Intel Low Power Subsystem PWM controller driver
3 *
4 * Copyright (C) 2014, Intel Corporation
5 *
6 * Derived from the original pwm-lpss.c
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/acpi.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/platform_device.h>
17#include <linux/pm_runtime.h>
18
19#include "pwm-lpss.h"
20
21/* BayTrail */
22static const struct pwm_lpss_boardinfo pwm_lpss_byt_info = {
23 .clk_rate = 25000000,
24 .npwm = 1,
25 .base_unit_bits = 16,
26};
27
28/* Braswell */
29static const struct pwm_lpss_boardinfo pwm_lpss_bsw_info = {
30 .clk_rate = 19200000,
31 .npwm = 1,
32 .base_unit_bits = 16,
33 .other_devices_aml_touches_pwm_regs = true,
34};
35
36/* Broxton */
37static const struct pwm_lpss_boardinfo pwm_lpss_bxt_info = {
38 .clk_rate = 19200000,
39 .npwm = 4,
40 .base_unit_bits = 22,
41 .bypass = true,
42};
43
44static int pwm_lpss_probe_platform(struct platform_device *pdev)
45{
46 const struct pwm_lpss_boardinfo *info;
47 const struct acpi_device_id *id;
48 struct pwm_lpss_chip *lpwm;
49 struct resource *r;
50
51 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev);
52 if (!id)
53 return -ENODEV;
54
55 info = (const struct pwm_lpss_boardinfo *)id->driver_data;
56 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
57
58 lpwm = pwm_lpss_probe(&pdev->dev, r, info);
59 if (IS_ERR(lpwm))
60 return PTR_ERR(lpwm);
61
62 platform_set_drvdata(pdev, lpwm);
63
64 dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_SMART_PREPARE);
65 pm_runtime_set_active(&pdev->dev);
66 pm_runtime_enable(&pdev->dev);
67
68 return 0;
69}
70
71static int pwm_lpss_remove_platform(struct platform_device *pdev)
72{
73 struct pwm_lpss_chip *lpwm = platform_get_drvdata(pdev);
74
75 pm_runtime_disable(&pdev->dev);
76 return pwm_lpss_remove(lpwm);
77}
78
79static int pwm_lpss_prepare(struct device *dev)
80{
81 struct pwm_lpss_chip *lpwm = dev_get_drvdata(dev);
82
83 /*
84 * If other device's AML code touches the PWM regs on suspend/resume
85 * force runtime-resume the PWM controller to allow this.
86 */
87 if (lpwm->info->other_devices_aml_touches_pwm_regs)
88 return 0; /* Force runtime-resume */
89
90 return 1; /* If runtime-suspended leave as is */
91}
92
93static const struct dev_pm_ops pwm_lpss_platform_pm_ops = {
94 .prepare = pwm_lpss_prepare,
95 SET_SYSTEM_SLEEP_PM_OPS(pwm_lpss_suspend, pwm_lpss_resume)
96};
97
98static const struct acpi_device_id pwm_lpss_acpi_match[] = {
99 { "80860F09", (unsigned long)&pwm_lpss_byt_info },
100 { "80862288", (unsigned long)&pwm_lpss_bsw_info },
101 { "80862289", (unsigned long)&pwm_lpss_bsw_info },
102 { "80865AC8", (unsigned long)&pwm_lpss_bxt_info },
103 { },
104};
105MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match);
106
107static struct platform_driver pwm_lpss_driver_platform = {
108 .driver = {
109 .name = "pwm-lpss",
110 .acpi_match_table = pwm_lpss_acpi_match,
111 .pm = &pwm_lpss_platform_pm_ops,
112 },
113 .probe = pwm_lpss_probe_platform,
114 .remove = pwm_lpss_remove_platform,
115};
116module_platform_driver(pwm_lpss_driver_platform);
117
118MODULE_DESCRIPTION("PWM platform driver for Intel LPSS");
119MODULE_LICENSE("GPL v2");
120MODULE_ALIAS("platform:pwm-lpss");