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 #include <linux/olpc-ec.h>
  17
  18 #include <acpi/acpi_bus.h>
  19 #include <acpi/acpi_drivers.h>
  20 #include <asm/olpc.h>
  21
  22 #define DRV_NAME                        "olpc-xo15-sci"
  23 #define PFX                             DRV_NAME ": "
  24 #define XO15_SCI_CLASS                  DRV_NAME
  25 #define XO15_SCI_DEVICE_NAME            "OLPC XO-1.5 SCI"
  26
  27 static unsigned long                    xo15_sci_gpe;
  28 static bool                             lid_wake_on_close;
  29
  30 /*
  31  * The normal ACPI LID wakeup behavior is wake-on-open, but not
  32  * wake-on-close. This is implemented as standard by the XO-1.5 DSDT.
  33  *
  34  * We provide here a sysfs attribute that will additionally enable
  35  * wake-on-close behavior. This is useful (e.g.) when we oportunistically
  36  * suspend with the display running; if the lid is then closed, we want to
  37  * wake up to turn the display off.
  38  *
  39  * This is controlled through a custom method in the XO-1.5 DSDT.
  40  */
  41 static int set_lid_wake_behavior(bool wake_on_close)
  42 {
  43         struct acpi_object_list arg_list;
  44         union acpi_object arg;
  45         acpi_status status;
  46
  47         arg_list.count          = 1;
  48         arg_list.pointer        = &arg;
  49         arg.type                = ACPI_TYPE_INTEGER;
  50         arg.integer.value       = wake_on_close;
  51
  52         status = acpi_evaluate_object(NULL, "\\_SB.PCI0.LID.LIDW", &arg_list, NULL);
  53         if (ACPI_FAILURE(status)) {
  54                 pr_warning(PFX "failed to set lid behavior\n");
  55                 return 1;
  56         }
  57
  58         lid_wake_on_close = wake_on_close;
  59
  60         return 0;
  61 }
  62
  63 static ssize_t
  64 lid_wake_on_close_show(struct kobject *s, struct kobj_attribute *attr, char *buf)
  65 {
  66         return sprintf(buf, "%u\n", lid_wake_on_close);
  67 }
  68
  69 static ssize_t lid_wake_on_close_store(struct kobject *s,
  70                                        struct kobj_attribute *attr,
  71                                        const char *buf, size_t n)
  72 {
  73         unsigned int val;
  74
  75         if (sscanf(buf, "%u", &val) != 1)
  76                 return -EINVAL;
  77
  78         set_lid_wake_behavior(!!val);
  79
  80         return n;
  81 }
  82
  83 static struct kobj_attribute lid_wake_on_close_attr =
  84         __ATTR(lid_wake_on_close, 0644,
  85                lid_wake_on_close_show,
  86                lid_wake_on_close_store);
  87
  88 static void battery_status_changed(void)
  89 {
  90         struct power_supply *psy = power_supply_get_by_name("olpc-battery");
  91
  92         if (psy) {
  93                 power_supply_changed(psy);
  94                 put_device(psy->dev);
  95         }
  96 }
  97
  98 static void ac_status_changed(void)
  99 {
 100         struct power_supply *psy = power_supply_get_by_name("olpc-ac");
 101
 102         if (psy) {
 103                 power_supply_changed(psy);
 104                 put_device(psy->dev);
 105         }
 106 }
 107
 108 static void process_sci_queue(void)
 109 {
 110         u16 data;
 111         int r;
 112
 113         do {
 114                 r = olpc_ec_sci_query(&data);
 115                 if (r || !data)
 116                         break;
 117
 118                 pr_debug(PFX "SCI 0x%x received\n", data);
 119
 120                 switch (data) {
 121                 case EC_SCI_SRC_BATERR:
 122                 case EC_SCI_SRC_BATSOC:
 123                 case EC_SCI_SRC_BATTERY:
 124                 case EC_SCI_SRC_BATCRIT:
 125                         battery_status_changed();
 126                         break;
 127                 case EC_SCI_SRC_ACPWR:
 128                         ac_status_changed();
 129                         break;
 130                 }
 131         } while (data);
 132
 133         if (r)
 134                 pr_err(PFX "Failed to clear SCI queue");
 135 }
 136
 137 static void process_sci_queue_work(struct work_struct *work)
 138 {
 139         process_sci_queue();
 140 }
 141
 142 static DECLARE_WORK(sci_work, process_sci_queue_work);
 143
 144 static u32 xo15_sci_gpe_handler(acpi_handle gpe_device, u32 gpe, void *context)
 145 {
 146         schedule_work(&sci_work);
 147         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 148 }
 149
 150 static int xo15_sci_add(struct acpi_device *device)
 151 {
 152         unsigned long long tmp;
 153         acpi_status status;
 154         int r;
 155
 156         if (!device)
 157                 return -EINVAL;
 158
 159         strcpy(acpi_device_name(device), XO15_SCI_DEVICE_NAME);
 160         strcpy(acpi_device_class(device), XO15_SCI_CLASS);
 161
 162         /* Get GPE bit assignment (EC events). */
 163         status = acpi_evaluate_integer(device->handle, "_GPE", NULL, &tmp);
 164         if (ACPI_FAILURE(status))
 165                 return -EINVAL;
 166
 167         xo15_sci_gpe = tmp;
 168         status = acpi_install_gpe_handler(NULL, xo15_sci_gpe,
 169                                           ACPI_GPE_EDGE_TRIGGERED,
 170                                           xo15_sci_gpe_handler, device);
 171         if (ACPI_FAILURE(status))
 172                 return -ENODEV;
 173
 174         dev_info(&device->dev, "Initialized, GPE = 0x%lx\n", xo15_sci_gpe);
 175
 176         r = sysfs_create_file(&device->dev.kobj, &lid_wake_on_close_attr.attr);
 177         if (r)
 178                 goto err_sysfs;
 179
 180         /* Flush queue, and enable all SCI events */
 181         process_sci_queue();
 182         olpc_ec_mask_write(EC_SCI_SRC_ALL);
 183
 184         acpi_enable_gpe(NULL, xo15_sci_gpe);
 185
 186         /* Enable wake-on-EC */
 187         if (device->wakeup.flags.valid)
 188                 device_init_wakeup(&device->dev, true);
 189
 190         return 0;
 191
 192 err_sysfs:
 193         acpi_remove_gpe_handler(NULL, xo15_sci_gpe, xo15_sci_gpe_handler);
 194         cancel_work_sync(&sci_work);
 195         return r;
 196 }
 197
 198 static int xo15_sci_remove(struct acpi_device *device)
 199 {
 200         acpi_disable_gpe(NULL, xo15_sci_gpe);
 201         acpi_remove_gpe_handler(NULL, xo15_sci_gpe, xo15_sci_gpe_handler);
 202         cancel_work_sync(&sci_work);
 203         sysfs_remove_file(&device->dev.kobj, &lid_wake_on_close_attr.attr);
 204         return 0;
 205 }
 206
 207 static int xo15_sci_resume(struct device *dev)
 208 {
 209         /* Enable all EC events */
 210         olpc_ec_mask_write(EC_SCI_SRC_ALL);
 211
 212         /* Power/battery status might have changed */
 213         battery_status_changed();
 214         ac_status_changed();
 215
 216         return 0;
 217 }
 218
 219 static SIMPLE_DEV_PM_OPS(xo15_sci_pm, NULL, xo15_sci_resume);
 220
 221 static const struct acpi_device_id xo15_sci_device_ids[] = {
 222         {"XO15EC", 0},
 223         {"", 0},
 224 };
 225
 226 static struct acpi_driver xo15_sci_drv = {
 227         .name = DRV_NAME,
 228         .class = XO15_SCI_CLASS,
 229         .ids = xo15_sci_device_ids,
 230         .ops = {
 231                 .add = xo15_sci_add,
 232                 .remove = xo15_sci_remove,
 233         },
 234         .drv.pm = &xo15_sci_pm,
 235 };
 236
 237 static int __init xo15_sci_init(void)
 238 {
 239         return acpi_bus_register_driver(&xo15_sci_drv);
 240 }
 241 device_initcall(xo15_sci_init);