summaryrefslogtreecommitdiffstats
path: root/drivers/power/reset/gemini-poweroff.c
blob: de878fd26f27a82a86cfc6f514d5ddbdd5b797dc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
/*
 * Gemini power management controller
 * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
 *
 * Inspired by code from the SL3516 board support by Jason Lee
 * Inspired by code from Janos Laube <janos.dev@gmail.com>
 */
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/bitops.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/reboot.h>

#define GEMINI_PWC_ID		0x00010500
#define	GEMINI_PWC_IDREG	0x00
#define	GEMINI_PWC_CTRLREG	0x04
#define	GEMINI_PWC_STATREG	0x08

#define GEMINI_CTRL_SHUTDOWN	BIT(0)
#define GEMINI_CTRL_ENABLE	BIT(1)
#define GEMINI_CTRL_IRQ_CLR	BIT(2)

#define GEMINI_STAT_CIR		BIT(4)
#define	GEMINI_STAT_RTC		BIT(5)
#define	GEMINI_STAT_POWERBUTTON	BIT(6)

struct gemini_powercon {
        struct device           *dev;
        void __iomem            *base;
};

static irqreturn_t gemini_powerbutton_interrupt(int irq, void *data)
{
	struct gemini_powercon *gpw = data;
	u32 val;

	/* ACK the IRQ */
	val = readl(gpw->base + GEMINI_PWC_CTRLREG);
	val |= GEMINI_CTRL_IRQ_CLR;
	writel(val, gpw->base + GEMINI_PWC_CTRLREG);

	val = readl(gpw->base + GEMINI_PWC_STATREG);
	val &= 0x70U;
	switch (val) {
	case GEMINI_STAT_CIR:
		dev_info(gpw->dev, "infrared poweroff\n");
		orderly_poweroff(true);
		break;
	case GEMINI_STAT_RTC:
		dev_info(gpw->dev, "RTC poweroff\n");
		orderly_poweroff(true);
		break;
	case GEMINI_STAT_POWERBUTTON:
		dev_info(gpw->dev, "poweroff button pressed\n");
		orderly_poweroff(true);
		break;
	default:
		dev_info(gpw->dev, "other power management IRQ\n");
		break;
	}

	return IRQ_HANDLED;
}

/* This callback needs this static local as it has void as argument */
static struct gemini_powercon *gpw_poweroff;

static void gemini_poweroff(void)
{
	struct gemini_powercon *gpw = gpw_poweroff;
	u32 val;

	dev_crit(gpw->dev, "Gemini power off\n");
	val = readl(gpw->base + GEMINI_PWC_CTRLREG);
	val |= GEMINI_CTRL_ENABLE | GEMINI_CTRL_IRQ_CLR;
	writel(val, gpw->base + GEMINI_PWC_CTRLREG);

	val &= ~GEMINI_CTRL_ENABLE;
	val |= GEMINI_CTRL_SHUTDOWN;
	writel(val, gpw->base + GEMINI_PWC_CTRLREG);
}

static int gemini_poweroff_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct resource *res;
	struct gemini_powercon *gpw;
	u32 val;
	int irq;
	int ret;

	gpw = devm_kzalloc(dev, sizeof(*gpw), GFP_KERNEL);
	if (!gpw)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	gpw->base = devm_ioremap_resource(dev, res);
	if (IS_ERR(gpw->base))
		return PTR_ERR(gpw->base);

	irq = platform_get_irq(pdev, 0);
	if (!irq)
		return -EINVAL;

	gpw->dev = dev;

	val = readl(gpw->base + GEMINI_PWC_IDREG);
	val &= 0xFFFFFF00U;
	if (val != GEMINI_PWC_ID) {
		dev_err(dev, "wrong power controller ID: %08x\n",
			val);
		return -ENODEV;
	}

	/* Clear the power management IRQ */
	val = readl(gpw->base + GEMINI_PWC_CTRLREG);
	val |= GEMINI_CTRL_IRQ_CLR;
	writel(val, gpw->base + GEMINI_PWC_CTRLREG);

	ret = devm_request_irq(dev, irq, gemini_powerbutton_interrupt, 0,
			       "poweroff", gpw);
	if (ret)
		return ret;

	pm_power_off = gemini_poweroff;
	gpw_poweroff = gpw;

	/*
	 * Enable the power controller. This is crucial on Gemini
	 * systems: if this is not done, pressing the power button
	 * will result in unconditional poweroff without any warning.
	 * This makes the kernel handle the poweroff.
	 */
	val = readl(gpw->base + GEMINI_PWC_CTRLREG);
	val |= GEMINI_CTRL_ENABLE;
	writel(val, gpw->base + GEMINI_PWC_CTRLREG);

	dev_info(dev, "Gemini poweroff driver registered\n");

	return 0;
}

static const struct of_device_id gemini_poweroff_of_match[] = {
	{
		.compatible = "cortina,gemini-power-controller",
	},
	{}
};

static struct platform_driver gemini_poweroff_driver = {
	.probe = gemini_poweroff_probe,
	.driver = {
		.name = "gemini-poweroff",
		.of_match_table = gemini_poweroff_of_match,
	},
};
builtin_platform_driver(gemini_poweroff_driver);
OpenPOWER on IntegriCloud