1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Power off through MediaTek PMIC |
4 | * |
5 | * Copyright (C) 2018 MediaTek Inc. |
6 | * |
7 | * Author: Sean Wang <sean.wang@mediatek.com> |
8 | * |
9 | */ |
10 | |
11 | #include <linux/err.h> |
12 | #include <linux/module.h> |
13 | #include <linux/of.h> |
14 | #include <linux/platform_device.h> |
15 | #include <linux/mfd/mt6397/core.h> |
16 | #include <linux/mfd/mt6397/rtc.h> |
17 | #include <linux/reboot.h> |
18 | |
19 | struct mt6323_pwrc { |
20 | struct device *dev; |
21 | struct regmap *regmap; |
22 | u32 base; |
23 | }; |
24 | |
25 | static int mt6323_do_pwroff(struct sys_off_data *data) |
26 | { |
27 | struct mt6323_pwrc *pwrc = data->cb_data; |
28 | unsigned int val; |
29 | int ret; |
30 | |
31 | regmap_write(map: pwrc->regmap, reg: pwrc->base + RTC_BBPU, RTC_BBPU_KEY); |
32 | regmap_write(map: pwrc->regmap, reg: pwrc->base + RTC_WRTGR_MT6323, val: 1); |
33 | |
34 | ret = regmap_read_poll_timeout(pwrc->regmap, |
35 | pwrc->base + RTC_BBPU, val, |
36 | !(val & RTC_BBPU_CBUSY), |
37 | MTK_RTC_POLL_DELAY_US, |
38 | MTK_RTC_POLL_TIMEOUT); |
39 | if (ret) |
40 | dev_err(pwrc->dev, "failed to write BBPU: %d\n" , ret); |
41 | |
42 | /* Wait some time until system down, otherwise, notice with a warn */ |
43 | mdelay(1000); |
44 | |
45 | WARN_ONCE(1, "Unable to power off system\n" ); |
46 | |
47 | return NOTIFY_DONE; |
48 | } |
49 | |
50 | static int mt6323_pwrc_probe(struct platform_device *pdev) |
51 | { |
52 | struct mt6397_chip *mt6397_chip = dev_get_drvdata(dev: pdev->dev.parent); |
53 | struct mt6323_pwrc *pwrc; |
54 | struct resource *res; |
55 | int ret; |
56 | |
57 | pwrc = devm_kzalloc(dev: &pdev->dev, size: sizeof(*pwrc), GFP_KERNEL); |
58 | if (!pwrc) |
59 | return -ENOMEM; |
60 | |
61 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
62 | if (!res) |
63 | return -EINVAL; |
64 | |
65 | pwrc->base = res->start; |
66 | pwrc->regmap = mt6397_chip->regmap; |
67 | pwrc->dev = &pdev->dev; |
68 | |
69 | ret = devm_register_sys_off_handler(dev: pwrc->dev, |
70 | mode: SYS_OFF_MODE_POWER_OFF, |
71 | SYS_OFF_PRIO_DEFAULT, |
72 | callback: mt6323_do_pwroff, |
73 | cb_data: pwrc); |
74 | if (ret) |
75 | return dev_err_probe(dev: pwrc->dev, err: ret, fmt: "failed to register power-off handler\n" ); |
76 | |
77 | return 0; |
78 | } |
79 | |
80 | static const struct of_device_id mt6323_pwrc_dt_match[] = { |
81 | { .compatible = "mediatek,mt6323-pwrc" }, |
82 | {}, |
83 | }; |
84 | MODULE_DEVICE_TABLE(of, mt6323_pwrc_dt_match); |
85 | |
86 | static struct platform_driver mt6323_pwrc_driver = { |
87 | .probe = mt6323_pwrc_probe, |
88 | .driver = { |
89 | .name = "mt6323-pwrc" , |
90 | .of_match_table = mt6323_pwrc_dt_match, |
91 | }, |
92 | }; |
93 | |
94 | module_platform_driver(mt6323_pwrc_driver); |
95 | |
96 | MODULE_DESCRIPTION("Poweroff driver for MT6323 PMIC" ); |
97 | MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>" ); |
98 | |