blob: ff75af5abbc536c837aad62348fff3cd79e70719 [file] [log] [blame]
Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001// SPDX-License-Identifier: GPL-2.0
Linus Walleijf7a388d2017-03-12 23:36:21 +01002/*
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
31struct gemini_powercon {
32 struct device *dev;
33 void __iomem *base;
34};
35
36static 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(gpw->base + GEMINI_PWC_CTRLREG);
43 val |= GEMINI_CTRL_IRQ_CLR;
44 writel(val, gpw->base + GEMINI_PWC_CTRLREG);
45
46 val = readl(gpw->base + GEMINI_PWC_STATREG);
47 val &= 0x70U;
48 switch (val) {
49 case GEMINI_STAT_CIR:
50 dev_info(gpw->dev, "infrared poweroff\n");
51 orderly_poweroff(true);
52 break;
53 case GEMINI_STAT_RTC:
54 dev_info(gpw->dev, "RTC poweroff\n");
55 orderly_poweroff(true);
56 break;
57 case GEMINI_STAT_POWERBUTTON:
58 dev_info(gpw->dev, "poweroff button pressed\n");
59 orderly_poweroff(true);
60 break;
61 default:
62 dev_info(gpw->dev, "other power management IRQ\n");
63 break;
64 }
65
66 return IRQ_HANDLED;
67}
68
69/* This callback needs this static local as it has void as argument */
70static struct gemini_powercon *gpw_poweroff;
71
72static void gemini_poweroff(void)
73{
74 struct gemini_powercon *gpw = gpw_poweroff;
75 u32 val;
76
77 dev_crit(gpw->dev, "Gemini power off\n");
78 val = readl(gpw->base + GEMINI_PWC_CTRLREG);
79 val |= GEMINI_CTRL_ENABLE | GEMINI_CTRL_IRQ_CLR;
80 writel(val, gpw->base + GEMINI_PWC_CTRLREG);
81
82 val &= ~GEMINI_CTRL_ENABLE;
83 val |= GEMINI_CTRL_SHUTDOWN;
84 writel(val, gpw->base + GEMINI_PWC_CTRLREG);
85}
86
87static int gemini_poweroff_probe(struct platform_device *pdev)
88{
89 struct device *dev = &pdev->dev;
90 struct resource *res;
91 struct gemini_powercon *gpw;
92 u32 val;
93 int irq;
94 int ret;
95
96 gpw = devm_kzalloc(dev, sizeof(*gpw), GFP_KERNEL);
97 if (!gpw)
98 return -ENOMEM;
99
100 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
101 gpw->base = devm_ioremap_resource(dev, res);
102 if (IS_ERR(gpw->base))
103 return PTR_ERR(gpw->base);
104
105 irq = platform_get_irq(pdev, 0);
106 if (!irq)
107 return -EINVAL;
108
109 gpw->dev = dev;
110
111 val = readl(gpw->base + GEMINI_PWC_IDREG);
112 val &= 0xFFFFFF00U;
113 if (val != GEMINI_PWC_ID) {
114 dev_err(dev, "wrong power controller ID: %08x\n",
115 val);
116 return -ENODEV;
117 }
118
119 /* Clear the power management IRQ */
120 val = readl(gpw->base + GEMINI_PWC_CTRLREG);
121 val |= GEMINI_CTRL_IRQ_CLR;
122 writel(val, gpw->base + GEMINI_PWC_CTRLREG);
123
124 ret = devm_request_irq(dev, irq, gemini_powerbutton_interrupt, 0,
125 "poweroff", gpw);
126 if (ret)
127 return ret;
128
129 pm_power_off = gemini_poweroff;
130 gpw_poweroff = gpw;
131
132 /*
133 * Enable the power controller. This is crucial on Gemini
134 * systems: if this is not done, pressing the power button
135 * will result in unconditional poweroff without any warning.
136 * This makes the kernel handle the poweroff.
137 */
138 val = readl(gpw->base + GEMINI_PWC_CTRLREG);
139 val |= GEMINI_CTRL_ENABLE;
140 writel(val, gpw->base + GEMINI_PWC_CTRLREG);
141
142 dev_info(dev, "Gemini poweroff driver registered\n");
143
144 return 0;
145}
146
147static const struct of_device_id gemini_poweroff_of_match[] = {
148 {
149 .compatible = "cortina,gemini-power-controller",
150 },
151 {}
152};
153
154static struct platform_driver gemini_poweroff_driver = {
155 .probe = gemini_poweroff_probe,
156 .driver = {
157 .name = "gemini-poweroff",
158 .of_match_table = gemini_poweroff_of_match,
159 },
160};
161builtin_platform_driver(gemini_poweroff_driver);