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/pm.h>
18 #include <linux/mfd/core.h>
19 #include <linux/suspend.h>
20 
21 #include <asm/io.h>
22 #include <asm/olpc.h>
23 
24 #define DRV_NAME "olpc-xo1-pm"
25 
26 static unsigned long acpi_base;
27 static unsigned long pms_base;
28 
29 static u16 wakeup_mask = CS5536_PM_PWRBTN;
30 
31 static struct {
32 	unsigned long address;
33 	unsigned short segment;
34 } ofw_bios_entry = { 0xF0000 + PAGE_OFFSET, __KERNEL_CS };
35 
36 /* Set bits in the wakeup mask */
37 void olpc_xo1_pm_wakeup_set(u16 value)
38 {
39 	wakeup_mask |= value;
40 }
41 EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_set);
42 
43 /* Clear bits in the wakeup mask */
44 void olpc_xo1_pm_wakeup_clear(u16 value)
45 {
46 	wakeup_mask &= ~value;
47 }
48 EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_clear);
49 
50 static int xo1_power_state_enter(suspend_state_t pm_state)
51 {
52 	unsigned long saved_sci_mask;
53 	int r;
54 
55 	/* Only STR is supported */
56 	if (pm_state != PM_SUSPEND_MEM)
57 		return -EINVAL;
58 
59 	r = olpc_ec_cmd(EC_SET_SCI_INHIBIT, NULL, 0, NULL, 0);
60 	if (r)
61 		return r;
62 
63 	/*
64 	 * Save SCI mask (this gets lost since PM1_EN is used as a mask for
65 	 * wakeup events, which is not necessarily the same event set)
66 	 */
67 	saved_sci_mask = inl(acpi_base + CS5536_PM1_STS);
68 	saved_sci_mask &= 0xffff0000;
69 
70 	/* Save CPU state */
71 	do_olpc_suspend_lowlevel();
72 
73 	/* Resume path starts here */
74 
75 	/* Restore SCI mask (using dword access to CS5536_PM1_EN) */
76 	outl(saved_sci_mask, acpi_base + CS5536_PM1_STS);
77 
78 	/* Tell the EC to stop inhibiting SCIs */
79 	olpc_ec_cmd(EC_SET_SCI_INHIBIT_RELEASE, NULL, 0, NULL, 0);
80 
81 	/*
82 	 * Tell the wireless module to restart USB communication.
83 	 * Must be done twice.
84 	 */
85 	olpc_ec_cmd(EC_WAKE_UP_WLAN, NULL, 0, NULL, 0);
86 	olpc_ec_cmd(EC_WAKE_UP_WLAN, NULL, 0, NULL, 0);
87 
88 	return 0;
89 }
90 
91 asmlinkage int xo1_do_sleep(u8 sleep_state)
92 {
93 	void *pgd_addr = __va(read_cr3());
94 
95 	/* Program wakeup mask (using dword access to CS5536_PM1_EN) */
96 	outl(wakeup_mask << 16, acpi_base + CS5536_PM1_STS);
97 
98 	__asm__("movl %0,%%eax" : : "r" (pgd_addr));
99 	__asm__("call *(%%edi); cld"
100 		: : "D" (&ofw_bios_entry));
101 	__asm__("movb $0x34, %al\n\t"
102 		"outb %al, $0x70\n\t"
103 		"movb $0x30, %al\n\t"
104 		"outb %al, $0x71\n\t");
105 	return 0;
106 }
107 
108 static void xo1_power_off(void)
109 {
110 	printk(KERN_INFO "OLPC XO-1 power off sequence...\n");
111 
112 	/* Enable all of these controls with 0 delay */
113 	outl(0x40000000, pms_base + CS5536_PM_SCLK);
114 	outl(0x40000000, pms_base + CS5536_PM_IN_SLPCTL);
115 	outl(0x40000000, pms_base + CS5536_PM_WKXD);
116 	outl(0x40000000, pms_base + CS5536_PM_WKD);
117 
118 	/* Clear status bits (possibly unnecessary) */
119 	outl(0x0002ffff, pms_base  + CS5536_PM_SSC);
120 	outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
121 
122 	/* Write SLP_EN bit to start the machinery */
123 	outl(0x00002000, acpi_base + CS5536_PM1_CNT);
124 }
125 
126 static int xo1_power_state_valid(suspend_state_t pm_state)
127 {
128 	/* suspend-to-RAM only */
129 	return pm_state == PM_SUSPEND_MEM;
130 }
131 
132 static const struct platform_suspend_ops xo1_suspend_ops = {
133 	.valid = xo1_power_state_valid,
134 	.enter = xo1_power_state_enter,
135 };
136 
137 static int __devinit xo1_pm_probe(struct platform_device *pdev)
138 {
139 	struct resource *res;
140 	int err;
141 
142 	/* don't run on non-XOs */
143 	if (!machine_is_olpc())
144 		return -ENODEV;
145 
146 	err = mfd_cell_enable(pdev);
147 	if (err)
148 		return err;
149 
150 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
151 	if (!res) {
152 		dev_err(&pdev->dev, "can't fetch device resource info\n");
153 		return -EIO;
154 	}
155 	if (strcmp(pdev->name, "cs5535-pms") == 0)
156 		pms_base = res->start;
157 	else if (strcmp(pdev->name, "olpc-xo1-pm-acpi") == 0)
158 		acpi_base = res->start;
159 
160 	/* If we have both addresses, we can override the poweroff hook */
161 	if (pms_base && acpi_base) {
162 		suspend_set_ops(&xo1_suspend_ops);
163 		pm_power_off = xo1_power_off;
164 		printk(KERN_INFO "OLPC XO-1 support registered\n");
165 	}
166 
167 	return 0;
168 }
169 
170 static int __devexit xo1_pm_remove(struct platform_device *pdev)
171 {
172 	mfd_cell_disable(pdev);
173 
174 	if (strcmp(pdev->name, "cs5535-pms") == 0)
175 		pms_base = 0;
176 	else if (strcmp(pdev->name, "olpc-xo1-pm-acpi") == 0)
177 		acpi_base = 0;
178 
179 	pm_power_off = NULL;
180 	return 0;
181 }
182 
183 static struct platform_driver cs5535_pms_driver = {
184 	.driver = {
185 		.name = "cs5535-pms",
186 		.owner = THIS_MODULE,
187 	},
188 	.probe = xo1_pm_probe,
189 	.remove = __devexit_p(xo1_pm_remove),
190 };
191 
192 static struct platform_driver cs5535_acpi_driver = {
193 	.driver = {
194 		.name = "olpc-xo1-pm-acpi",
195 		.owner = THIS_MODULE,
196 	},
197 	.probe = xo1_pm_probe,
198 	.remove = __devexit_p(xo1_pm_remove),
199 };
200 
201 static int __init xo1_pm_init(void)
202 {
203 	int r;
204 
205 	r = platform_driver_register(&cs5535_pms_driver);
206 	if (r)
207 		return r;
208 
209 	r = platform_driver_register(&cs5535_acpi_driver);
210 	if (r)
211 		platform_driver_unregister(&cs5535_pms_driver);
212 
213 	return r;
214 }
215 arch_initcall(xo1_pm_init);
216