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

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Support for power management features of the OLPC XO-1 laptop
   4  *
   5  * Copyright (C) 2010 Andres Salomon <dilinger@queued.net>
   6  * Copyright (C) 2010 One Laptop per Child
   7  * Copyright (C) 2006 Red Hat, Inc.
   8  * Copyright (C) 2006 Advanced Micro Devices, Inc.
   9  */
  10
  11 #include <linux/cs5535.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/export.h>
  14 #include <linux/pm.h>
  15 #include <linux/suspend.h>
  16 #include <linux/olpc-ec.h>
  17
  18 #include <asm/io.h>
  19 #include <asm/olpc.h>
  20
  21 #define DRV_NAME "olpc-xo1-pm"
  22
  23 static unsigned long acpi_base;
  24 static unsigned long pms_base;
  25
  26 static u16 wakeup_mask = CS5536_PM_PWRBTN;
  27
  28 static struct {
  29         unsigned long address;
  30         unsigned short segment;
  31 } ofw_bios_entry = { 0xF0000 + PAGE_OFFSET, __KERNEL_CS };
  32
  33 /* Set bits in the wakeup mask */
  34 void olpc_xo1_pm_wakeup_set(u16 value)
  35 {
  36         wakeup_mask |= value;
  37 }
  38 EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_set);
  39
  40 /* Clear bits in the wakeup mask */
  41 void olpc_xo1_pm_wakeup_clear(u16 value)
  42 {
  43         wakeup_mask &= ~value;
  44 }
  45 EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_clear);
  46
  47 static int xo1_power_state_enter(suspend_state_t pm_state)
  48 {
  49         unsigned long saved_sci_mask;
  50
  51         /* Only STR is supported */
  52         if (pm_state != PM_SUSPEND_MEM)
  53                 return -EINVAL;
  54
  55         /*
  56          * Save SCI mask (this gets lost since PM1_EN is used as a mask for
  57          * wakeup events, which is not necessarily the same event set)
  58          */
  59         saved_sci_mask = inl(acpi_base + CS5536_PM1_STS);
  60         saved_sci_mask &= 0xffff0000;
  61
  62         /* Save CPU state */
  63         do_olpc_suspend_lowlevel();
  64
  65         /* Resume path starts here */
  66
  67         /* Restore SCI mask (using dword access to CS5536_PM1_EN) */
  68         outl(saved_sci_mask, acpi_base + CS5536_PM1_STS);
  69
  70         return 0;
  71 }
  72
  73 asmlinkage __visible int xo1_do_sleep(u8 sleep_state)
  74 {
  75         void *pgd_addr = __va(read_cr3_pa());
  76
  77         /* Program wakeup mask (using dword access to CS5536_PM1_EN) */
  78         outl(wakeup_mask << 16, acpi_base + CS5536_PM1_STS);
  79
  80         __asm__("movl %0,%%eax" : : "r" (pgd_addr));
  81         __asm__("call *(%%edi); cld"
  82                 : : "D" (&ofw_bios_entry));
  83         __asm__("movb $0x34, %al\n\t"
  84                 "outb %al, $0x70\n\t"
  85                 "movb $0x30, %al\n\t"
  86                 "outb %al, $0x71\n\t");
  87         return 0;
  88 }
  89
  90 static void xo1_power_off(void)
  91 {
  92         printk(KERN_INFO "OLPC XO-1 power off sequence...\n");
  93
  94         /* Enable all of these controls with 0 delay */
  95         outl(0x40000000, pms_base + CS5536_PM_SCLK);
  96         outl(0x40000000, pms_base + CS5536_PM_IN_SLPCTL);
  97         outl(0x40000000, pms_base + CS5536_PM_WKXD);
  98         outl(0x40000000, pms_base + CS5536_PM_WKD);
  99
 100         /* Clear status bits (possibly unnecessary) */
 101         outl(0x0002ffff, pms_base  + CS5536_PM_SSC);
 102         outl(0xffffffff, acpi_base + CS5536_PM_GPE0_STS);
 103
 104         /* Write SLP_EN bit to start the machinery */
 105         outl(0x00002000, acpi_base + CS5536_PM1_CNT);
 106 }
 107
 108 static int xo1_power_state_valid(suspend_state_t pm_state)
 109 {
 110         /* suspend-to-RAM only */
 111         return pm_state == PM_SUSPEND_MEM;
 112 }
 113
 114 static const struct platform_suspend_ops xo1_suspend_ops = {
 115         .valid = xo1_power_state_valid,
 116         .enter = xo1_power_state_enter,
 117 };
 118
 119 static int xo1_pm_probe(struct platform_device *pdev)
 120 {
 121         struct resource *res;
 122
 123         /* don't run on non-XOs */
 124         if (!machine_is_olpc())
 125                 return -ENODEV;
 126
 127         res = platform_get_resource(pdev, IORESOURCE_IO, 0);
 128         if (!res) {
 129                 dev_err(&pdev->dev, "can't fetch device resource info\n");
 130                 return -EIO;
 131         }
 132         if (strcmp(pdev->name, "cs5535-pms") == 0)
 133                 pms_base = res->start;
 134         else if (strcmp(pdev->name, "olpc-xo1-pm-acpi") == 0)
 135                 acpi_base = res->start;
 136
 137         /* If we have both addresses, we can override the poweroff hook */
 138         if (pms_base && acpi_base) {
 139                 suspend_set_ops(&xo1_suspend_ops);
 140                 pm_power_off = xo1_power_off;
 141                 printk(KERN_INFO "OLPC XO-1 support registered\n");
 142         }
 143
 144         return 0;
 145 }
 146
 147 static int xo1_pm_remove(struct platform_device *pdev)
 148 {
 149         if (strcmp(pdev->name, "cs5535-pms") == 0)
 150                 pms_base = 0;
 151         else if (strcmp(pdev->name, "olpc-xo1-pm-acpi") == 0)
 152                 acpi_base = 0;
 153
 154         pm_power_off = NULL;
 155         return 0;
 156 }
 157
 158 static struct platform_driver cs5535_pms_driver = {
 159         .driver = {
 160                 .name = "cs5535-pms",
 161         },
 162         .probe = xo1_pm_probe,
 163         .remove = xo1_pm_remove,
 164 };
 165
 166 static struct platform_driver cs5535_acpi_driver = {
 167         .driver = {
 168                 .name = "olpc-xo1-pm-acpi",
 169         },
 170         .probe = xo1_pm_probe,
 171         .remove = xo1_pm_remove,
 172 };
 173
 174 static int __init xo1_pm_init(void)
 175 {
 176         int r;
 177
 178         r = platform_driver_register(&cs5535_pms_driver);
 179         if (r)
 180                 return r;
 181
 182         r = platform_driver_register(&cs5535_acpi_driver);
 183         if (r)
 184                 platform_driver_unregister(&cs5535_pms_driver);
 185
 186         return r;
 187 }
 188 arch_initcall(xo1_pm_init);