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 | /* This callback needs this static local as it has void as argument */ |
74 | static struct gemini_powercon *gpw_poweroff; |
75 | |
76 | static void gemini_poweroff(void) |
77 | { |
78 | struct gemini_powercon *gpw = gpw_poweroff; |
79 | u32 val; |
80 | |
81 | dev_crit(gpw->dev, "Gemini power off\n" ); |
82 | val = readl(addr: gpw->base + GEMINI_PWC_CTRLREG); |
83 | val |= GEMINI_CTRL_ENABLE | GEMINI_CTRL_IRQ_CLR; |
84 | writel(val, addr: gpw->base + GEMINI_PWC_CTRLREG); |
85 | |
86 | val &= ~GEMINI_CTRL_ENABLE; |
87 | val |= GEMINI_CTRL_SHUTDOWN; |
88 | writel(val, addr: gpw->base + GEMINI_PWC_CTRLREG); |
89 | } |
90 | |
91 | static int gemini_poweroff_probe(struct platform_device *pdev) |
92 | { |
93 | struct device *dev = &pdev->dev; |
94 | struct gemini_powercon *gpw; |
95 | u32 val; |
96 | int irq; |
97 | int ret; |
98 | |
99 | gpw = devm_kzalloc(dev, size: sizeof(*gpw), GFP_KERNEL); |
100 | if (!gpw) |
101 | return -ENOMEM; |
102 | |
103 | gpw->base = devm_platform_ioremap_resource(pdev, index: 0); |
104 | if (IS_ERR(ptr: gpw->base)) |
105 | return PTR_ERR(ptr: gpw->base); |
106 | |
107 | irq = platform_get_irq(pdev, 0); |
108 | if (irq < 0) |
109 | return irq; |
110 | |
111 | gpw->dev = dev; |
112 | |
113 | val = readl(addr: gpw->base + GEMINI_PWC_IDREG); |
114 | val &= 0xFFFFFF00U; |
115 | if (val != GEMINI_PWC_ID) { |
116 | dev_err(dev, "wrong power controller ID: %08x\n" , |
117 | val); |
118 | return -ENODEV; |
119 | } |
120 | |
121 | /* |
122 | * Enable the power controller. This is crucial on Gemini |
123 | * systems: if this is not done, pressing the power button |
124 | * will result in unconditional poweroff without any warning. |
125 | * This makes the kernel handle the poweroff. |
126 | */ |
127 | val = readl(addr: gpw->base + GEMINI_PWC_CTRLREG); |
128 | val |= GEMINI_CTRL_ENABLE; |
129 | writel(val, addr: gpw->base + GEMINI_PWC_CTRLREG); |
130 | |
131 | /* Clear the IRQ */ |
132 | val = readl(addr: gpw->base + GEMINI_PWC_CTRLREG); |
133 | val |= GEMINI_CTRL_IRQ_CLR; |
134 | writel(val, addr: gpw->base + GEMINI_PWC_CTRLREG); |
135 | |
136 | /* Wait for this to clear */ |
137 | val = readl(addr: gpw->base + GEMINI_PWC_STATREG); |
138 | while (val & 0x70U) |
139 | val = readl(addr: gpw->base + GEMINI_PWC_STATREG); |
140 | |
141 | /* Clear the IRQ again */ |
142 | val = readl(addr: gpw->base + GEMINI_PWC_CTRLREG); |
143 | val |= GEMINI_CTRL_IRQ_CLR; |
144 | writel(val, addr: gpw->base + GEMINI_PWC_CTRLREG); |
145 | |
146 | ret = devm_request_irq(dev, irq, handler: gemini_powerbutton_interrupt, irqflags: 0, |
147 | devname: "poweroff" , dev_id: gpw); |
148 | if (ret) |
149 | return ret; |
150 | |
151 | pm_power_off = gemini_poweroff; |
152 | gpw_poweroff = gpw; |
153 | |
154 | dev_info(dev, "Gemini poweroff driver registered\n" ); |
155 | |
156 | return 0; |
157 | } |
158 | |
159 | static const struct of_device_id gemini_poweroff_of_match[] = { |
160 | { |
161 | .compatible = "cortina,gemini-power-controller" , |
162 | }, |
163 | {} |
164 | }; |
165 | |
166 | static struct platform_driver gemini_poweroff_driver = { |
167 | .probe = gemini_poweroff_probe, |
168 | .driver = { |
169 | .name = "gemini-poweroff" , |
170 | .of_match_table = gemini_poweroff_of_match, |
171 | }, |
172 | }; |
173 | builtin_platform_driver(gemini_poweroff_driver); |
174 | |