1/*
2 * Support for power management features of the OLPC XO-1 laptop
3 *
4 * Copyright (C) 2010 Andres Salomon <dilinger@queued.net>
5 * Copyright (C) 2010 One Laptop per Child
6 * Copyright (C) 2006 Red Hat, Inc.
7 * Copyright (C) 2006 Advanced Micro Devices, Inc.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 */
14
15#include <linux/cs5535.h>
16#include <linux/platform_device.h>
17#include <linux/export.h>
18#include <linux/pm.h>
19#include <linux/mfd/core.h>
20#include <linux/suspend.h>
21#include <linux/olpc-ec.h>
22
23#include <asm/io.h>
24#include <asm/olpc.h>
25
26#define DRV_NAME "olpc-xo1-pm"
27
28static unsigned long acpi_base;
29static unsigned long pms_base;
30
31static u16 wakeup_mask = CS5536_PM_PWRBTN;
32
33static struct {
34	unsigned long address;
35	unsigned short segment;
36} ofw_bios_entry = { 0xF0000 + PAGE_OFFSET, __KERNEL_CS };
37
38/* Set bits in the wakeup mask */
39void olpc_xo1_pm_wakeup_set(u16 value)
40{
41	wakeup_mask |= value;
42}
43EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_set);
44
45/* Clear bits in the wakeup mask */
46void olpc_xo1_pm_wakeup_clear(u16 value)
47{
48	wakeup_mask &= ~value;
49}
50EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_clear);
51
52static int xo1_power_state_enter(suspend_state_t pm_state)
53{
54	unsigned long saved_sci_mask;
55
56	/* Only STR is supported */
57	if (pm_state != PM_SUSPEND_MEM)
58		return -EINVAL;
59
60	/*
61	 * Save SCI mask (this gets lost since PM1_EN is used as a mask for
62	 * wakeup events, which is not necessarily the same event set)
63	 */
64	saved_sci_mask = inl(acpi_base + CS5536_PM1_STS);
65	saved_sci_mask &= 0xffff0000;
66
67	/* Save CPU state */
68	do_olpc_suspend_lowlevel();
69
70	/* Resume path starts here */
71
72	/* Restore SCI mask (using dword access to CS5536_PM1_EN) */
73	outl(saved_sci_mask, acpi_base + CS5536_PM1_STS);
74
75	return 0;
76}
77
78asmlinkage __visible int xo1_do_sleep(u8 sleep_state)
79{
80	void *pgd_addr = __va(read_cr3());
81
82	/* Program wakeup mask (using dword access to CS5536_PM1_EN) */
83	outl(wakeup_mask << 16, acpi_base + CS5536_PM1_STS);
84
85	__asm__("movl %0,%%eax" : : "r" (pgd_addr));
86	__asm__("call *(%%edi); cld"
87		: : "D" (&ofw_bios_entry));
88	__asm__("movb $0x34, %al\n\t"
89		"outb %al, $0x70\n\t"
90		"movb $0x30, %al\n\t"
91		"outb %al, $0x71\n\t");
92	return 0;
93}
94
95static void xo1_power_off(void)
96{
97	printk(KERN_INFO "OLPC XO-1 power off sequence...\n");
98
99	/* Enable all of these controls with 0 delay */
100	outl(0x40000000, pms_base + CS5536_PM_SCLK);
101	outl(0x40000000, pms_base + CS5536_PM_IN_SLPCTL);
102	outl(0x40000000, pms_base + CS5536_PM_WKXD);
103	outl(0x40000000, pms_base + CS5536_PM_WKD);
104
105	/* Clear status bits (possibly unnecessary) */
106	outl(0x0002ffff, pms_base  + CS5536_PM_SSC);
107	outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
108
109	/* Write SLP_EN bit to start the machinery */
110	outl(0x00002000, acpi_base + CS5536_PM1_CNT);
111}
112
113static int xo1_power_state_valid(suspend_state_t pm_state)
114{
115	/* suspend-to-RAM only */
116	return pm_state == PM_SUSPEND_MEM;
117}
118
119static const struct platform_suspend_ops xo1_suspend_ops = {
120	.valid = xo1_power_state_valid,
121	.enter = xo1_power_state_enter,
122};
123
124static int xo1_pm_probe(struct platform_device *pdev)
125{
126	struct resource *res;
127	int err;
128
129	/* don't run on non-XOs */
130	if (!machine_is_olpc())
131		return -ENODEV;
132
133	err = mfd_cell_enable(pdev);
134	if (err)
135		return err;
136
137	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
138	if (!res) {
139		dev_err(&pdev->dev, "can't fetch device resource info\n");
140		return -EIO;
141	}
142	if (strcmp(pdev->name, "cs5535-pms") == 0)
143		pms_base = res->start;
144	else if (strcmp(pdev->name, "olpc-xo1-pm-acpi") == 0)
145		acpi_base = res->start;
146
147	/* If we have both addresses, we can override the poweroff hook */
148	if (pms_base && acpi_base) {
149		suspend_set_ops(&xo1_suspend_ops);
150		pm_power_off = xo1_power_off;
151		printk(KERN_INFO "OLPC XO-1 support registered\n");
152	}
153
154	return 0;
155}
156
157static int xo1_pm_remove(struct platform_device *pdev)
158{
159	mfd_cell_disable(pdev);
160
161	if (strcmp(pdev->name, "cs5535-pms") == 0)
162		pms_base = 0;
163	else if (strcmp(pdev->name, "olpc-xo1-pm-acpi") == 0)
164		acpi_base = 0;
165
166	pm_power_off = NULL;
167	return 0;
168}
169
170static struct platform_driver cs5535_pms_driver = {
171	.driver = {
172		.name = "cs5535-pms",
173	},
174	.probe = xo1_pm_probe,
175	.remove = xo1_pm_remove,
176};
177
178static struct platform_driver cs5535_acpi_driver = {
179	.driver = {
180		.name = "olpc-xo1-pm-acpi",
181	},
182	.probe = xo1_pm_probe,
183	.remove = xo1_pm_remove,
184};
185
186static int __init xo1_pm_init(void)
187{
188	int r;
189
190	r = platform_driver_register(&cs5535_pms_driver);
191	if (r)
192		return r;
193
194	r = platform_driver_register(&cs5535_acpi_driver);
195	if (r)
196		platform_driver_unregister(&cs5535_pms_driver);
197
198	return r;
199}
200arch_initcall(xo1_pm_init);
201