arch/x86/platform/olpc/olpc-xo1-pm.c

   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_pa());
  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);