summaryrefslogtreecommitdiffstats
path: root/arch/x86/platform/olpc/olpc-xo1-pm.c
blob: 0668aaff8bfe50bbe0fe19d2d4ba193409143ae4 (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
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
/*
 * Support for power management features of the OLPC XO-1 laptop
 *
 * Copyright (C) 2010 Andres Salomon <dilinger@queued.net>
 * Copyright (C) 2010 One Laptop per Child
 * Copyright (C) 2006 Red Hat, Inc.
 * Copyright (C) 2006 Advanced Micro Devices, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/cs5535.h>
#include <linux/platform_device.h>
#include <linux/export.h>
#include <linux/pm.h>
#include <linux/mfd/core.h>
#include <linux/suspend.h>
#include <linux/olpc-ec.h>

#include <asm/io.h>
#include <asm/olpc.h>

#define DRV_NAME "olpc-xo1-pm"

static unsigned long acpi_base;
static unsigned long pms_base;

static u16 wakeup_mask = CS5536_PM_PWRBTN;

static struct {
	unsigned long address;
	unsigned short segment;
} ofw_bios_entry = { 0xF0000 + PAGE_OFFSET, __KERNEL_CS };

/* Set bits in the wakeup mask */
void olpc_xo1_pm_wakeup_set(u16 value)
{
	wakeup_mask |= value;
}
EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_set);

/* Clear bits in the wakeup mask */
void olpc_xo1_pm_wakeup_clear(u16 value)
{
	wakeup_mask &= ~value;
}
EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_clear);

static int xo1_power_state_enter(suspend_state_t pm_state)
{
	unsigned long saved_sci_mask;

	/* Only STR is supported */
	if (pm_state != PM_SUSPEND_MEM)
		return -EINVAL;

	/*
	 * Save SCI mask (this gets lost since PM1_EN is used as a mask for
	 * wakeup events, which is not necessarily the same event set)
	 */
	saved_sci_mask = inl(acpi_base + CS5536_PM1_STS);
	saved_sci_mask &= 0xffff0000;

	/* Save CPU state */
	do_olpc_suspend_lowlevel();

	/* Resume path starts here */

	/* Restore SCI mask (using dword access to CS5536_PM1_EN) */
	outl(saved_sci_mask, acpi_base + CS5536_PM1_STS);

	return 0;
}

asmlinkage __visible int xo1_do_sleep(u8 sleep_state)
{
	void *pgd_addr = __va(read_cr3_pa());

	/* Program wakeup mask (using dword access to CS5536_PM1_EN) */
	outl(wakeup_mask << 16, acpi_base + CS5536_PM1_STS);

	__asm__("movl %0,%%eax" : : "r" (pgd_addr));
	__asm__("call *(%%edi); cld"
		: : "D" (&ofw_bios_entry));
	__asm__("movb $0x34, %al\n\t"
		"outb %al, $0x70\n\t"
		"movb $0x30, %al\n\t"
		"outb %al, $0x71\n\t");
	return 0;
}

static void xo1_power_off(void)
{
	printk(KERN_INFO "OLPC XO-1 power off sequence...\n");

	/* Enable all of these controls with 0 delay */
	outl(0x40000000, pms_base + CS5536_PM_SCLK);
	outl(0x40000000, pms_base + CS5536_PM_IN_SLPCTL);
	outl(0x40000000, pms_base + CS5536_PM_WKXD);
	outl(0x40000000, pms_base + CS5536_PM_WKD);

	/* Clear status bits (possibly unnecessary) */
	outl(0x0002ffff, pms_base  + CS5536_PM_SSC);
	outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);

	/* Write SLP_EN bit to start the machinery */
	outl(0x00002000, acpi_base + CS5536_PM1_CNT);
}

static int xo1_power_state_valid(suspend_state_t pm_state)
{
	/* suspend-to-RAM only */
	return pm_state == PM_SUSPEND_MEM;
}

static const struct platform_suspend_ops xo1_suspend_ops = {
	.valid = xo1_power_state_valid,
	.enter = xo1_power_state_enter,
};

static int xo1_pm_probe(struct platform_device *pdev)
{
	struct resource *res;
	int err;

	/* don't run on non-XOs */
	if (!machine_is_olpc())
		return -ENODEV;

	err = mfd_cell_enable(pdev);
	if (err)
		return err;

	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
	if (!res) {
		dev_err(&pdev->dev, "can't fetch device resource info\n");
		return -EIO;
	}
	if (strcmp(pdev->name, "cs5535-pms") == 0)
		pms_base = res->start;
	else if (strcmp(pdev->name, "olpc-xo1-pm-acpi") == 0)
		acpi_base = res->start;

	/* If we have both addresses, we can override the poweroff hook */
	if (pms_base && acpi_base) {
		suspend_set_ops(&xo1_suspend_ops);
		pm_power_off = xo1_power_off;
		printk(KERN_INFO "OLPC XO-1 support registered\n");
	}

	return 0;
}

static int xo1_pm_remove(struct platform_device *pdev)
{
	mfd_cell_disable(pdev);

	if (strcmp(pdev->name, "cs5535-pms") == 0)
		pms_base = 0;
	else if (strcmp(pdev->name, "olpc-xo1-pm-acpi") == 0)
		acpi_base = 0;

	pm_power_off = NULL;
	return 0;
}

static struct platform_driver cs5535_pms_driver = {
	.driver = {
		.name = "cs5535-pms",
	},
	.probe = xo1_pm_probe,
	.remove = xo1_pm_remove,
};

static struct platform_driver cs5535_acpi_driver = {
	.driver = {
		.name = "olpc-xo1-pm-acpi",
	},
	.probe = xo1_pm_probe,
	.remove = xo1_pm_remove,
};

static int __init xo1_pm_init(void)
{
	int r;

	r = platform_driver_register(&cs5535_pms_driver);
	if (r)
		return r;

	r = platform_driver_register(&cs5535_acpi_driver);
	if (r)
		platform_driver_unregister(&cs5535_pms_driver);

	return r;
}
arch_initcall(xo1_pm_init);