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olpc-xo1-pm.c
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1 /*
2  * Support for power management features of the OLPC XO-1 laptop
3  *
4  * Copyright (C) 2010 Andres Salomon <[email protected]>
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 */
40 {
41  wakeup_mask |= value;
42 }
44 
45 /* Clear bits in the wakeup mask */
47 {
48  wakeup_mask &= ~value;
49 }
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 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 __devinit 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 __devexit 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  .owner = THIS_MODULE,
174  },
175  .probe = xo1_pm_probe,
176  .remove = __devexit_p(xo1_pm_remove),
177 };
178 
179 static struct platform_driver cs5535_acpi_driver = {
180  .driver = {
181  .name = "olpc-xo1-pm-acpi",
182  .owner = THIS_MODULE,
183  },
184  .probe = xo1_pm_probe,
185  .remove = __devexit_p(xo1_pm_remove),
186 };
187 
188 static int __init xo1_pm_init(void)
189 {
190  int r;
191 
192  r = platform_driver_register(&cs5535_pms_driver);
193  if (r)
194  return r;
195 
196  r = platform_driver_register(&cs5535_acpi_driver);
197  if (r)
198  platform_driver_unregister(&cs5535_pms_driver);
199 
200  return r;
201 }
202 arch_initcall(xo1_pm_init);