linux/arch/x86/platform/olpc/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 <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
  28static unsigned long acpi_base;
  29static unsigned long pms_base;
  30
  31static u16 wakeup_mask = CS5536_PM_PWRBTN;
  32
  33static 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 */
  39void olpc_xo1_pm_wakeup_set(u16 value)
  40{
  41        wakeup_mask |= value;
  42}
  43EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_set);
  44
  45/* Clear bits in the wakeup mask */
  46void olpc_xo1_pm_wakeup_clear(u16 value)
  47{
  48        wakeup_mask &= ~value;
  49}
  50EXPORT_SYMBOL_GPL(olpc_xo1_pm_wakeup_clear);
  51
  52static 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
  78asmlinkage __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
  95static 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
 113static 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
 119static const struct platform_suspend_ops xo1_suspend_ops = {
 120        .valid = xo1_power_state_valid,
 121        .enter = xo1_power_state_enter,
 122};
 123
 124static 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
 157static 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
 170static 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
 178static 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
 186static 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}
 200arch_initcall(xo1_pm_init);
 201