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
  51         status = acpi_evaluate_object(NULL, "\\_SB.PCI0.LID.LIDW", &arg_list, 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
  59         return 0;
  60 }
  61
  62 static ssize_t
  63 lid_wake_on_close_show(struct kobject *s, struct kobj_attribute *attr, char *buf)
  64 {
  65         return sprintf(buf, "%u\n", lid_wake_on_close);
  66 }
  67
  68 static ssize_t lid_wake_on_close_store(struct kobject *s,
  69                                        struct kobj_attribute *attr,
  70                                        const char *buf, size_t n)
  71 {
  72         unsigned int val;
  73
  74         if (sscanf(buf, "%u", &val) != 1)
  75                 return -EINVAL;
  76
  77         set_lid_wake_behavior(!!val);
  78
  79         return n;
  80 }
  81
  82 static struct kobj_attribute lid_wake_on_close_attr =
  83         __ATTR(lid_wake_on_close, 0644,
  84                lid_wake_on_close_show,
  85                lid_wake_on_close_store);
  86
  87 static void battery_status_changed(void)
  88 {
  89         struct power_supply *psy = power_supply_get_by_name("olpc-battery");
  90
  91         if (psy) {
  92                 power_supply_changed(psy);
  93                 put_device(psy->dev);
  94         }
  95 }
  96
  97 static void ac_status_changed(void)
  98 {
  99         struct power_supply *psy = power_supply_get_by_name("olpc-ac");
 100
 101         if (psy) {
 102                 power_supply_changed(psy);
 103                 put_device(psy->dev);
 104         }
 105 }
 106
 107 static void process_sci_queue(void)
 108 {
 109         u16 data;
 110         int r;
 111
 112         do {
 113                 r = olpc_ec_sci_query(&data);
 114                 if (r || !data)
 115                         break;
 116
 117                 pr_debug(PFX "SCI 0x%x received\n", data);
 118
 119                 switch (data) {
 120                 case EC_SCI_SRC_BATERR:
 121                 case EC_SCI_SRC_BATSOC:
 122                 case EC_SCI_SRC_BATTERY:
 123                 case EC_SCI_SRC_BATCRIT:
 124                         battery_status_changed();
 125                         break;
 126                 case EC_SCI_SRC_ACPWR:
 127                         ac_status_changed();
 128                         break;
 129                 }
 130         } while (data);
 131
 132         if (r)
 133                 pr_err(PFX "Failed to clear SCI queue");
 134 }
 135
 136 static void process_sci_queue_work(struct work_struct *work)
 137 {
 138         process_sci_queue();
 139 }
 140
 141 static DECLARE_WORK(sci_work, process_sci_queue_work);
 142
 143 static u32 xo15_sci_gpe_handler(acpi_handle gpe_device, u32 gpe, void *context)
 144 {
 145         schedule_work(&sci_work);
 146         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 147 }
 148
 149 static int xo15_sci_add(struct acpi_device *device)
 150 {
 151         unsigned long long tmp;
 152         acpi_status status;
 153         int r;
 154
 155         if (!device)
 156                 return -EINVAL;
 157
 158         strcpy(acpi_device_name(device), XO15_SCI_DEVICE_NAME);
 159         strcpy(acpi_device_class(device), XO15_SCI_CLASS);
 160
 161         /* Get GPE bit assignment (EC events). */
 162         status = acpi_evaluate_integer(device->handle, "_GPE", NULL, &tmp);
 163         if (ACPI_FAILURE(status))
 164                 return -EINVAL;
 165
 166         xo15_sci_gpe = tmp;
 167         status = acpi_install_gpe_handler(NULL, xo15_sci_gpe,
 168                                           ACPI_GPE_EDGE_TRIGGERED,
 169                                           xo15_sci_gpe_handler, device);
 170         if (ACPI_FAILURE(status))
 171                 return -ENODEV;
 172
 173         dev_info(&device->dev, "Initialized, GPE = 0x%lx\n", xo15_sci_gpe);
 174
 175         r = sysfs_create_file(&device->dev.kobj, &lid_wake_on_close_attr.attr);
 176         if (r)
 177                 goto err_sysfs;
 178
 179         /* Flush queue, and enable all SCI events */
 180         process_sci_queue();
 181         olpc_ec_mask_write(EC_SCI_SRC_ALL);
 182
 183         acpi_enable_gpe(NULL, xo15_sci_gpe);
 184
 185         /* Enable wake-on-EC */
 186         if (device->wakeup.flags.valid)
 187                 device_init_wakeup(&device->dev, true);
 188
 189         return 0;
 190
 191 err_sysfs:
 192         acpi_remove_gpe_handler(NULL, xo15_sci_gpe, xo15_sci_gpe_handler);
 193         cancel_work_sync(&sci_work);
 194         return r;
 195 }
 196
 197 static int xo15_sci_remove(struct acpi_device *device, int type)
 198 {
 199         acpi_disable_gpe(NULL, xo15_sci_gpe);
 200         acpi_remove_gpe_handler(NULL, xo15_sci_gpe, xo15_sci_gpe_handler);
 201         cancel_work_sync(&sci_work);
 202         sysfs_remove_file(&device->dev.kobj, &lid_wake_on_close_attr.attr);
 203         return 0;
 204 }
 205
 206 static int xo15_sci_resume(struct device *dev)
 207 {
 208         /* Enable all EC events */
 209         olpc_ec_mask_write(EC_SCI_SRC_ALL);
 210
 211         /* Power/battery status might have changed */
 212         battery_status_changed();
 213         ac_status_changed();
 214
 215         return 0;
 216 }
 217
 218 static SIMPLE_DEV_PM_OPS(xo15_sci_pm, NULL, xo15_sci_resume);
 219
 220 static const struct acpi_device_id xo15_sci_device_ids[] = {
 221         {"XO15EC", 0},
 222         {"", 0},
 223 };
 224
 225 static struct acpi_driver xo15_sci_drv = {
 226         .name = DRV_NAME,
 227         .class = XO15_SCI_CLASS,
 228         .ids = xo15_sci_device_ids,
 229         .ops = {
 230                 .add = xo15_sci_add,
 231                 .remove = xo15_sci_remove,
 232         },
 233         .drv.pm = &xo15_sci_pm,
 234 };
 235
 236 static int __init xo15_sci_init(void)
 237 {
 238         return acpi_bus_register_driver(&xo15_sci_drv);
 239 }
 240 device_initcall(xo15_sci_init);