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 
28 static unsigned long acpi_base;
29 static unsigned long pms_base;
30 
31 static u16 wakeup_mask = CS5536_PM_PWRBTN;
32 
33 static 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 */
39 void olpc_xo1_pm_wakeup_set(u16 value)
40 {
41 	wakeup_mask |= value;
42 }
43 EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_set);
44 
45 /* Clear bits in the wakeup mask */
46 void olpc_xo1_pm_wakeup_clear(u16 value)
47 {
48 	wakeup_mask &= ~value;
49 }
50 EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_clear);
51 
52 static 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 
78 asmlinkage __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 
95 static 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 
113 static 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 
119 static const struct platform_suspend_ops xo1_suspend_ops = {
120 	.valid = xo1_power_state_valid,
121 	.enter = xo1_power_state_enter,
122 };
123 
124 static 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 
157 static 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 
170 static 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 
178 static 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 
186 static 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 }
200 arch_initcall(xo1_pm_init);
201