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 | |
20 | static 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 | |
63 | static void pwm_lpss_remove_platform(struct platform_device *pdev) |
64 | { |
65 | pm_runtime_disable(dev: &pdev->dev); |
66 | } |
67 | |
68 | static 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 | }; |
75 | MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match); |
76 | |
77 | static 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 | }; |
85 | module_platform_driver(pwm_lpss_driver_platform); |
86 | |
87 | MODULE_DESCRIPTION("PWM platform driver for Intel LPSS" ); |
88 | MODULE_LICENSE("GPL v2" ); |
89 | MODULE_IMPORT_NS(PWM_LPSS); |
90 | MODULE_ALIAS("platform:pwm-lpss" ); |
91 | |