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 static bool lid_wake_on_close;
  28
  29 /*
  30  * The normal ACPI LID wakeup behavior is wake-on-open, but not
  31  * wake-on-close. This is implemented as standard by the XO-1.5 DSDT.
  32  *
  33  * We provide here a sysfs attribute that will additionally enable
  34  * wake-on-close behavior. This is useful (e.g.) when we oportunistically
  35  * suspend with the display running; if the lid is then closed, we want to
  36  * wake up to turn the display off.
  37  *
  38  * This is controlled through a custom method in the XO-1.5 DSDT.
  39  */
  40 static int set_lid_wake_behavior(bool wake_on_close)
  41 {
  42         struct acpi_object_list arg_list;
  43         union acpi_object arg;
  44         acpi_status status;
  45
  46         arg_list.count = 1;
  47         arg_list.pointer = &arg;
  48         arg.type = ACPI_TYPE_INTEGER;
  49         arg.integer.value = wake_on_close;
  50         status = acpi_evaluate_object(NULL, "\\_SB.PCI0.LID.LIDW", &arg_list,
  51                                       NULL);
  52         if (ACPI_FAILURE(status)) {
  53                 pr_warning(PFX "failed to set lid behavior\n");
  54                 return 1;
  55         }
  56
  57         lid_wake_on_close = wake_on_close;
  58         return 0;
  59 }
  60
  61 static ssize_t lid_wake_on_close_show(struct kobject *s,
  62                                       struct kobj_attribute *attr, char *buf)
  63 {
  64         return sprintf(buf, "%u\n", lid_wake_on_close);
  65 }
  66
  67 static ssize_t lid_wake_on_close_store(struct kobject *s,
  68                                        struct kobj_attribute *attr,
  69                                        const char *buf, size_t n)
  70 {
  71         unsigned int val;
  72
  73         if (sscanf(buf, "%u", &val) != 1)
  74                 return -EINVAL;
  75
  76         set_lid_wake_behavior(!!val);
  77         return n;
  78 }
  79
  80 static struct kobj_attribute lid_wake_on_close_attr =
  81         __ATTR(lid_wake_on_close, 0644,
  82                lid_wake_on_close_show, lid_wake_on_close_store);
  83
  84 static void battery_status_changed(void)
  85 {
  86         struct power_supply *psy = power_supply_get_by_name("olpc-battery");
  87
  88         if (psy) {
  89                 power_supply_changed(psy);
  90                 put_device(psy->dev);
  91         }
  92 }
  93
  94 static void ac_status_changed(void)
  95 {
  96         struct power_supply *psy = power_supply_get_by_name("olpc-ac");
  97
  98         if (psy) {
  99                 power_supply_changed(psy);
 100                 put_device(psy->dev);
 101         }
 102 }
 103
 104 static void process_sci_queue(void)
 105 {
 106         u16 data;
 107         int r;
 108
 109         do {
 110                 r = olpc_ec_sci_query(&data);
 111                 if (r || !data)
 112                         break;
 113
 114                 pr_debug(PFX "SCI 0x%x received\n", data);
 115
 116                 switch (data) {
 117                 case EC_SCI_SRC_BATERR:
 118                 case EC_SCI_SRC_BATSOC:
 119                 case EC_SCI_SRC_BATTERY:
 120                 case EC_SCI_SRC_BATCRIT:
 121                         battery_status_changed();
 122                         break;
 123                 case EC_SCI_SRC_ACPWR:
 124                         ac_status_changed();
 125                         break;
 126                 }
 127         } while (data);
 128
 129         if (r)
 130                 pr_err(PFX "Failed to clear SCI queue");
 131 }
 132
 133 static void process_sci_queue_work(struct work_struct *work)
 134 {
 135         process_sci_queue();
 136 }
 137
 138 static DECLARE_WORK(sci_work, process_sci_queue_work);
 139
 140 static u32 xo15_sci_gpe_handler(acpi_handle gpe_device, u32 gpe, void *context)
 141 {
 142         schedule_work(&sci_work);
 143         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 144 }
 145
 146 static int xo15_sci_add(struct acpi_device *device)
 147 {
 148         unsigned long long tmp;
 149         acpi_status status;
 150         int r;
 151
 152         if (!device)
 153                 return -EINVAL;
 154
 155         strcpy(acpi_device_name(device), XO15_SCI_DEVICE_NAME);
 156         strcpy(acpi_device_class(device), XO15_SCI_CLASS);
 157
 158         /* Get GPE bit assignment (EC events). */
 159         status = acpi_evaluate_integer(device->handle, "_GPE", NULL, &tmp);
 160         if (ACPI_FAILURE(status))
 161                 return -EINVAL;
 162
 163         xo15_sci_gpe = tmp;
 164         status = acpi_install_gpe_handler(NULL, xo15_sci_gpe,
 165                                           ACPI_GPE_EDGE_TRIGGERED,
 166                                           xo15_sci_gpe_handler, device);
 167         if (ACPI_FAILURE(status))
 168                 return -ENODEV;
 169
 170         dev_info(&device->dev, "Initialized, GPE = 0x%lx\n", xo15_sci_gpe);
 171
 172         r = sysfs_create_file(&device->dev.kobj, &lid_wake_on_close_attr.attr);
 173         if (r)
 174                 goto err_sysfs;
 175
 176         /* Flush queue, and enable all SCI events */
 177         process_sci_queue();
 178         olpc_ec_mask_write(EC_SCI_SRC_ALL);
 179
 180         acpi_enable_gpe(NULL, xo15_sci_gpe);
 181
 182         /* Enable wake-on-EC */
 183         if (device->wakeup.flags.valid)
 184                 device_init_wakeup(&device->dev, true);
 185
 186         return 0;
 187
 188 err_sysfs:
 189         acpi_remove_gpe_handler(NULL, xo15_sci_gpe, xo15_sci_gpe_handler);
 190         cancel_work_sync(&sci_work);
 191         return r;
 192 }
 193
 194 static int xo15_sci_remove(struct acpi_device *device, int type)
 195 {
 196         acpi_disable_gpe(NULL, xo15_sci_gpe);
 197         acpi_remove_gpe_handler(NULL, xo15_sci_gpe, xo15_sci_gpe_handler);
 198         cancel_work_sync(&sci_work);
 199         sysfs_remove_file(&device->dev.kobj, &lid_wake_on_close_attr.attr);
 200         return 0;
 201 }
 202
 203 static int xo15_sci_resume(struct acpi_device *device)
 204 {
 205         /* Enable all EC events */
 206         olpc_ec_mask_write(EC_SCI_SRC_ALL);
 207
 208         /* Power/battery status might have changed */
 209         battery_status_changed();
 210         ac_status_changed();
 211
 212         return 0;
 213 }
 214
 215 static const struct acpi_device_id xo15_sci_device_ids[] = {
 216         {"XO15EC", 0},
 217         {"", 0},
 218 };
 219
 220 static struct acpi_driver xo15_sci_drv = {
 221         .name = DRV_NAME,
 222         .class = XO15_SCI_CLASS,
 223         .ids = xo15_sci_device_ids,
 224         .ops = {
 225                 .add = xo15_sci_add,
 226                 .remove = xo15_sci_remove,
 227                 .resume = xo15_sci_resume,
 228         },
 229 };
 230
 231 static int __init xo15_sci_init(void)
 232 {
 233         return acpi_bus_register_driver(&xo15_sci_drv);
 234 }
 235 device_initcall(xo15_sci_init);