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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(&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 chip = devm_pwm_lpss_probe(&pdev->dev, base, info);
35 if (IS_ERR(chip))
36 return PTR_ERR(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(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE|
55 DPM_FLAG_SMART_SUSPEND);
56
57 pm_runtime_set_active(&pdev->dev);
58 return devm_pm_runtime_enable(&pdev->dev);
59}
60
61static const struct acpi_device_id pwm_lpss_acpi_match[] = {
62 { "80860F09", (unsigned long)&pwm_lpss_byt_info },
63 { "80862288", (unsigned long)&pwm_lpss_bsw_info },
64 { "80862289", (unsigned long)&pwm_lpss_bsw_info },
65 { "80865AC8", (unsigned long)&pwm_lpss_bxt_info },
66 { },
67};
68MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match);
69
70static struct platform_driver pwm_lpss_driver_platform = {
71 .driver = {
72 .name = "pwm-lpss",
73 .acpi_match_table = pwm_lpss_acpi_match,
74 },
75 .probe = pwm_lpss_probe_platform,
76};
77module_platform_driver(pwm_lpss_driver_platform);
78
79MODULE_DESCRIPTION("PWM platform driver for Intel LPSS");
80MODULE_LICENSE("GPL v2");
81MODULE_IMPORT_NS("PWM_LPSS");
82MODULE_ALIAS("platform:pwm-lpss");
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 */
19static 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 */
26static 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 */
34static 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
41static 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 /*
62 * On Cherry Trail devices the GFX0._PS0 AML checks if the controller
63 * is on and if it is not on it turns it on and restores what it
64 * believes is the correct state to the PWM controller.
65 * Because of this we must disallow direct-complete, which keeps the
66 * controller (runtime)suspended on resume, to avoid 2 issues:
67 * 1. The controller getting turned on without the linux-pm code
68 * knowing about this. On devices where the controller is unused
69 * this causes it to stay on during the next suspend causing high
70 * battery drain (because S0i3 is not reached)
71 * 2. The state restoring code unexpectedly messing with the controller
72 *
73 * Leaving the controller runtime-suspended (skipping runtime-resume +
74 * normal-suspend) during suspend is fine.
75 */
76 if (info->other_devices_aml_touches_pwm_regs)
77 dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE|
78 DPM_FLAG_SMART_SUSPEND);
79
80 pm_runtime_set_active(&pdev->dev);
81 pm_runtime_enable(&pdev->dev);
82
83 return 0;
84}
85
86static int pwm_lpss_remove_platform(struct platform_device *pdev)
87{
88 pm_runtime_disable(&pdev->dev);
89 return 0;
90}
91
92static const struct acpi_device_id pwm_lpss_acpi_match[] = {
93 { "80860F09", (unsigned long)&pwm_lpss_byt_info },
94 { "80862288", (unsigned long)&pwm_lpss_bsw_info },
95 { "80862289", (unsigned long)&pwm_lpss_bsw_info },
96 { "80865AC8", (unsigned long)&pwm_lpss_bxt_info },
97 { },
98};
99MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match);
100
101static struct platform_driver pwm_lpss_driver_platform = {
102 .driver = {
103 .name = "pwm-lpss",
104 .acpi_match_table = pwm_lpss_acpi_match,
105 },
106 .probe = pwm_lpss_probe_platform,
107 .remove = pwm_lpss_remove_platform,
108};
109module_platform_driver(pwm_lpss_driver_platform);
110
111MODULE_DESCRIPTION("PWM platform driver for Intel LPSS");
112MODULE_LICENSE("GPL v2");
113MODULE_ALIAS("platform:pwm-lpss");