1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Gemini power management controller |
4 | * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org> |
5 | * |
6 | * Inspired by code from the SL3516 board support by Jason Lee |
7 | * Inspired by code from Janos Laube <janos.dev@gmail.com> |
8 | */ |
9 | #include <linux/of.h> |
10 | #include <linux/of_platform.h> |
11 | #include <linux/platform_device.h> |
12 | #include <linux/pm.h> |
13 | #include <linux/bitops.h> |
14 | #include <linux/interrupt.h> |
15 | #include <linux/io.h> |
16 | #include <linux/reboot.h> |
17 | |
18 | #define GEMINI_PWC_ID 0x00010500 |
19 | #define GEMINI_PWC_IDREG 0x00 |
20 | #define GEMINI_PWC_CTRLREG 0x04 |
21 | #define GEMINI_PWC_STATREG 0x08 |
22 | |
23 | #define GEMINI_CTRL_SHUTDOWN BIT(0) |
24 | #define GEMINI_CTRL_ENABLE BIT(1) |
25 | #define GEMINI_CTRL_IRQ_CLR BIT(2) |
26 | |
27 | #define GEMINI_STAT_CIR BIT(4) |
28 | #define GEMINI_STAT_RTC BIT(5) |
29 | #define GEMINI_STAT_POWERBUTTON BIT(6) |
30 | |
31 | struct gemini_powercon { |
32 | struct device *dev; |
33 | void __iomem *base; |
34 | }; |
35 | |
36 | static irqreturn_t gemini_powerbutton_interrupt(int irq, void *data) |
37 | { |
38 | struct gemini_powercon *gpw = data; |
39 | u32 val; |
40 | |
41 | /* ACK the IRQ */ |
42 | val = readl(addr: gpw->base + GEMINI_PWC_CTRLREG); |
43 | val |= GEMINI_CTRL_IRQ_CLR; |
44 | writel(val, addr: gpw->base + GEMINI_PWC_CTRLREG); |
45 | |
46 | val = readl(addr: gpw->base + GEMINI_PWC_STATREG); |
47 | val &= 0x70U; |
48 | switch (val) { |
49 | case GEMINI_STAT_CIR: |
50 | /* |
51 | * We do not yet have a driver for the infrared |
52 | * controller so it can cause spurious poweroff |
53 | * events. Ignore those for now. |
54 | */ |
55 | dev_info(gpw->dev, "infrared poweroff - ignored\n" ); |
56 | break; |
57 | case GEMINI_STAT_RTC: |
58 | dev_info(gpw->dev, "RTC poweroff\n" ); |
59 | orderly_poweroff(force: true); |
60 | break; |
61 | case GEMINI_STAT_POWERBUTTON: |
62 | dev_info(gpw->dev, "poweroff button pressed\n" ); |
63 | orderly_poweroff(force: true); |
64 | break; |
65 | default: |
66 | dev_info(gpw->dev, "other power management IRQ\n" ); |
67 | break; |
68 | } |
69 | |
70 | return IRQ_HANDLED; |
71 | } |
72 | |
73 | static int gemini_poweroff(struct sys_off_data *data) |
74 | { |
75 | struct gemini_powercon *gpw = data->cb_data; |
76 | u32 val; |
77 | |
78 | dev_crit(gpw->dev, "Gemini power off\n" ); |
79 | val = readl(addr: gpw->base + GEMINI_PWC_CTRLREG); |
80 | val |= GEMINI_CTRL_ENABLE | GEMINI_CTRL_IRQ_CLR; |
81 | writel(val, addr: gpw->base + GEMINI_PWC_CTRLREG); |
82 | |
83 | val &= ~GEMINI_CTRL_ENABLE; |
84 | val |= GEMINI_CTRL_SHUTDOWN; |
85 | writel(val, addr: gpw->base + GEMINI_PWC_CTRLREG); |
86 | |
87 | return NOTIFY_DONE; |
88 | } |
89 | |
90 | static int gemini_poweroff_probe(struct platform_device *pdev) |
91 | { |
92 | struct device *dev = &pdev->dev; |
93 | struct gemini_powercon *gpw; |
94 | u32 val; |
95 | int irq; |
96 | int ret; |
97 | |
98 | gpw = devm_kzalloc(dev, size: sizeof(*gpw), GFP_KERNEL); |
99 | if (!gpw) |
100 | return -ENOMEM; |
101 | |
102 | gpw->base = devm_platform_ioremap_resource(pdev, index: 0); |
103 | if (IS_ERR(ptr: gpw->base)) |
104 | return PTR_ERR(ptr: gpw->base); |
105 | |
106 | irq = platform_get_irq(pdev, 0); |
107 | if (irq < 0) |
108 | return irq; |
109 | |
110 | gpw->dev = dev; |
111 | |
112 | val = readl(addr: gpw->base + GEMINI_PWC_IDREG); |
113 | val &= 0xFFFFFF00U; |
114 | if (val != GEMINI_PWC_ID) { |
115 | dev_err(dev, "wrong power controller ID: %08x\n" , |
116 | val); |
117 | return -ENODEV; |
118 | } |
119 | |
120 | /* |
121 | * Enable the power controller. This is crucial on Gemini |
122 | * systems: if this is not done, pressing the power button |
123 | * will result in unconditional poweroff without any warning. |
124 | * This makes the kernel handle the poweroff. |
125 | */ |
126 | val = readl(addr: gpw->base + GEMINI_PWC_CTRLREG); |
127 | val |= GEMINI_CTRL_ENABLE; |
128 | writel(val, addr: gpw->base + GEMINI_PWC_CTRLREG); |
129 | |
130 | /* Clear the IRQ */ |
131 | val = readl(addr: gpw->base + GEMINI_PWC_CTRLREG); |
132 | val |= GEMINI_CTRL_IRQ_CLR; |
133 | writel(val, addr: gpw->base + GEMINI_PWC_CTRLREG); |
134 | |
135 | /* Wait for this to clear */ |
136 | val = readl(addr: gpw->base + GEMINI_PWC_STATREG); |
137 | while (val & 0x70U) |
138 | val = readl(addr: gpw->base + GEMINI_PWC_STATREG); |
139 | |
140 | /* Clear the IRQ again */ |
141 | val = readl(addr: gpw->base + GEMINI_PWC_CTRLREG); |
142 | val |= GEMINI_CTRL_IRQ_CLR; |
143 | writel(val, addr: gpw->base + GEMINI_PWC_CTRLREG); |
144 | |
145 | ret = devm_request_irq(dev, irq, handler: gemini_powerbutton_interrupt, irqflags: 0, |
146 | devname: "poweroff" , dev_id: gpw); |
147 | if (ret) |
148 | return ret; |
149 | |
150 | ret = devm_register_sys_off_handler(dev, mode: SYS_OFF_MODE_POWER_OFF, |
151 | SYS_OFF_PRIO_DEFAULT, |
152 | callback: gemini_poweroff, cb_data: gpw); |
153 | if (ret) |
154 | return ret; |
155 | |
156 | dev_info(dev, "Gemini poweroff driver registered\n" ); |
157 | |
158 | return 0; |
159 | } |
160 | |
161 | static const struct of_device_id gemini_poweroff_of_match[] = { |
162 | { |
163 | .compatible = "cortina,gemini-power-controller" , |
164 | }, |
165 | {} |
166 | }; |
167 | |
168 | static struct platform_driver gemini_poweroff_driver = { |
169 | .probe = gemini_poweroff_probe, |
170 | .driver = { |
171 | .name = "gemini-poweroff" , |
172 | .of_match_table = gemini_poweroff_of_match, |
173 | }, |
174 | }; |
175 | builtin_platform_driver(gemini_poweroff_driver); |
176 | |