arch/x86/platform/olpc/olpc-xo15-sci.c

   1 /*
   2  * Support for OLPC XO-1.5 System Control Interrupts (SCI)
   3  *
   4  * Copyright (C) 2009-2010 One Laptop per Child
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 #include <linux/device.h>
  13 #include <linux/slab.h>
  14 #include <linux/workqueue.h>
  15 #include <linux/power_supply.h>
  16
  17 #include <acpi/acpi_bus.h>
  18 #include <acpi/acpi_drivers.h>
  19 #include <asm/olpc.h>
  20
  21 #define DRV_NAME                        "olpc-xo15-sci"
  22 #define PFX                             DRV_NAME ": "
  23 #define XO15_SCI_CLASS                  DRV_NAME
  24 #define XO15_SCI_DEVICE_NAME            "OLPC XO-1.5 SCI"
  25
  26 static unsigned long xo15_sci_gpe;
  27
  28 static void battery_status_changed(void)
  29 {
  30         struct power_supply *psy = power_supply_get_by_name("olpc-battery");
  31
  32         if (psy) {
  33                 power_supply_changed(psy);
  34                 put_device(psy->dev);
  35         }
  36 }
  37
  38 static void ac_status_changed(void)
  39 {
  40         struct power_supply *psy = power_supply_get_by_name("olpc-ac");
  41
  42         if (psy) {
  43                 power_supply_changed(psy);
  44                 put_device(psy->dev);
  45         }
  46 }
  47
  48 static void process_sci_queue(void)
  49 {
  50         u16 data;
  51         int r;
  52
  53         do {
  54                 r = olpc_ec_sci_query(&data);
  55                 if (r || !data)
  56                         break;
  57
  58                 pr_debug(PFX "SCI 0x%x received\n", data);
  59
  60                 switch (data) {
  61                 case EC_SCI_SRC_BATERR:
  62                 case EC_SCI_SRC_BATSOC:
  63                 case EC_SCI_SRC_BATTERY:
  64                 case EC_SCI_SRC_BATCRIT:
  65                         battery_status_changed();
  66                         break;
  67                 case EC_SCI_SRC_ACPWR:
  68                         ac_status_changed();
  69                         break;
  70                 }
  71         } while (data);
  72
  73         if (r)
  74                 pr_err(PFX "Failed to clear SCI queue");
  75 }
  76
  77 static void process_sci_queue_work(struct work_struct *work)
  78 {
  79         process_sci_queue();
  80 }
  81
  82 static DECLARE_WORK(sci_work, process_sci_queue_work);
  83
  84 static u32 xo15_sci_gpe_handler(acpi_handle gpe_device, u32 gpe, void *context)
  85 {
  86         schedule_work(&sci_work);
  87         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
  88 }
  89
  90 static int xo15_sci_add(struct acpi_device *device)
  91 {
  92         unsigned long long tmp;
  93         acpi_status status;
  94
  95         if (!device)
  96                 return -EINVAL;
  97
  98         strcpy(acpi_device_name(device), XO15_SCI_DEVICE_NAME);
  99         strcpy(acpi_device_class(device), XO15_SCI_CLASS);
 100
 101         /* Get GPE bit assignment (EC events). */
 102         status = acpi_evaluate_integer(device->handle, "_GPE", NULL, &tmp);
 103         if (ACPI_FAILURE(status))
 104                 return -EINVAL;
 105
 106         xo15_sci_gpe = tmp;
 107         status = acpi_install_gpe_handler(NULL, xo15_sci_gpe,
 108                                           ACPI_GPE_EDGE_TRIGGERED,
 109                                           xo15_sci_gpe_handler, device);
 110         if (ACPI_FAILURE(status))
 111                 return -ENODEV;
 112
 113         dev_info(&device->dev, "Initialized, GPE = 0x%lx\n", xo15_sci_gpe);
 114
 115         /* Flush queue, and enable all SCI events */
 116         process_sci_queue();
 117         olpc_ec_mask_write(EC_SCI_SRC_ALL);
 118
 119         acpi_enable_gpe(NULL, xo15_sci_gpe);
 120
 121         /* Enable wake-on-EC */
 122         if (device->wakeup.flags.valid)
 123                 device_init_wakeup(&device->dev, true);
 124
 125         return 0;
 126 }
 127
 128 static int xo15_sci_remove(struct acpi_device *device, int type)
 129 {
 130         acpi_disable_gpe(NULL, xo15_sci_gpe);
 131         acpi_remove_gpe_handler(NULL, xo15_sci_gpe, xo15_sci_gpe_handler);
 132         cancel_work_sync(&sci_work);
 133         return 0;
 134 }
 135
 136 static int xo15_sci_resume(struct acpi_device *device)
 137 {
 138         /* Enable all EC events */
 139         olpc_ec_mask_write(EC_SCI_SRC_ALL);
 140
 141         /* Power/battery status might have changed */
 142         battery_status_changed();
 143         ac_status_changed();
 144
 145         return 0;
 146 }
 147
 148 static const struct acpi_device_id xo15_sci_device_ids[] = {
 149         {"XO15EC", 0},
 150         {"", 0},
 151 };
 152
 153 static struct acpi_driver xo15_sci_drv = {
 154         .name = DRV_NAME,
 155         .class = XO15_SCI_CLASS,
 156         .ids = xo15_sci_device_ids,
 157         .ops = {
 158                 .add = xo15_sci_add,
 159                 .remove = xo15_sci_remove,
 160                 .resume = xo15_sci_resume,
 161         },
 162 };
 163
 164 static int __init xo15_sci_init(void)
 165 {
 166         return acpi_bus_register_driver(&xo15_sci_drv);
 167 }
 168 device_initcall(xo15_sci_init);