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