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         acpi_status status;
  44
  45         status = acpi_execute_simple_method(NULL, "\\_SB.PCI0.LID.LIDW", wake_on_close);
  46         if (ACPI_FAILURE(status)) {
  47                 pr_warning(PFX "failed to set lid behavior\n");
  48                 return 1;
  49         }
  50
  51         lid_wake_on_close = wake_on_close;
  52
  53         return 0;
  54 }
  55
  56 static ssize_t
  57 lid_wake_on_close_show(struct kobject *s, struct kobj_attribute *attr, char *buf)
  58 {
  59         return sprintf(buf, "%u\n", lid_wake_on_close);
  60 }
  61
  62 static ssize_t lid_wake_on_close_store(struct kobject *s,
  63                                        struct kobj_attribute *attr,
  64                                        const char *buf, size_t n)
  65 {
  66         unsigned int val;
  67
  68         if (sscanf(buf, "%u", &val) != 1)
  69                 return -EINVAL;
  70
  71         set_lid_wake_behavior(!!val);
  72
  73         return n;
  74 }
  75
  76 static struct kobj_attribute lid_wake_on_close_attr =
  77         __ATTR(lid_wake_on_close, 0644,
  78                lid_wake_on_close_show,
  79                lid_wake_on_close_store);
  80
  81 static void battery_status_changed(void)
  82 {
  83         struct power_supply *psy = power_supply_get_by_name("olpc-battery");
  84
  85         if (psy) {
  86                 power_supply_changed(psy);
  87                 put_device(psy->dev);
  88         }
  89 }
  90
  91 static void ac_status_changed(void)
  92 {
  93         struct power_supply *psy = power_supply_get_by_name("olpc-ac");
  94
  95         if (psy) {
  96                 power_supply_changed(psy);
  97                 put_device(psy->dev);
  98         }
  99 }
 100
 101 static void process_sci_queue(void)
 102 {
 103         u16 data;
 104         int r;
 105
 106         do {
 107                 r = olpc_ec_sci_query(&data);
 108                 if (r || !data)
 109                         break;
 110
 111                 pr_debug(PFX "SCI 0x%x received\n", data);
 112
 113                 switch (data) {
 114                 case EC_SCI_SRC_BATERR:
 115                 case EC_SCI_SRC_BATSOC:
 116                 case EC_SCI_SRC_BATTERY:
 117                 case EC_SCI_SRC_BATCRIT:
 118                         battery_status_changed();
 119                         break;
 120                 case EC_SCI_SRC_ACPWR:
 121                         ac_status_changed();
 122                         break;
 123                 }
 124         } while (data);
 125
 126         if (r)
 127                 pr_err(PFX "Failed to clear SCI queue");
 128 }
 129
 130 static void process_sci_queue_work(struct work_struct *work)
 131 {
 132         process_sci_queue();
 133 }
 134
 135 static DECLARE_WORK(sci_work, process_sci_queue_work);
 136
 137 static u32 xo15_sci_gpe_handler(acpi_handle gpe_device, u32 gpe, void *context)
 138 {
 139         schedule_work(&sci_work);
 140         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 141 }
 142
 143 static int xo15_sci_add(struct acpi_device *device)
 144 {
 145         unsigned long long tmp;
 146         acpi_status status;
 147         int r;
 148
 149         if (!device)
 150                 return -EINVAL;
 151
 152         strcpy(acpi_device_name(device), XO15_SCI_DEVICE_NAME);
 153         strcpy(acpi_device_class(device), XO15_SCI_CLASS);
 154
 155         /* Get GPE bit assignment (EC events). */
 156         status = acpi_evaluate_integer(device->handle, "_GPE", NULL, &tmp);
 157         if (ACPI_FAILURE(status))
 158                 return -EINVAL;
 159
 160         xo15_sci_gpe = tmp;
 161         status = acpi_install_gpe_handler(NULL, xo15_sci_gpe,
 162                                           ACPI_GPE_EDGE_TRIGGERED,
 163                                           xo15_sci_gpe_handler, device);
 164         if (ACPI_FAILURE(status))
 165                 return -ENODEV;
 166
 167         dev_info(&device->dev, "Initialized, GPE = 0x%lx\n", xo15_sci_gpe);
 168
 169         r = sysfs_create_file(&device->dev.kobj, &lid_wake_on_close_attr.attr);
 170         if (r)
 171                 goto err_sysfs;
 172
 173         /* Flush queue, and enable all SCI events */
 174         process_sci_queue();
 175         olpc_ec_mask_write(EC_SCI_SRC_ALL);
 176
 177         acpi_enable_gpe(NULL, xo15_sci_gpe);
 178
 179         /* Enable wake-on-EC */
 180         if (device->wakeup.flags.valid)
 181                 device_init_wakeup(&device->dev, true);
 182
 183         return 0;
 184
 185 err_sysfs:
 186         acpi_remove_gpe_handler(NULL, xo15_sci_gpe, xo15_sci_gpe_handler);
 187         cancel_work_sync(&sci_work);
 188         return r;
 189 }
 190
 191 static int xo15_sci_remove(struct acpi_device *device)
 192 {
 193         acpi_disable_gpe(NULL, xo15_sci_gpe);
 194         acpi_remove_gpe_handler(NULL, xo15_sci_gpe, xo15_sci_gpe_handler);
 195         cancel_work_sync(&sci_work);
 196         sysfs_remove_file(&device->dev.kobj, &lid_wake_on_close_attr.attr);
 197         return 0;
 198 }
 199
 200 static int xo15_sci_resume(struct device *dev)
 201 {
 202         /* Enable all EC events */
 203         olpc_ec_mask_write(EC_SCI_SRC_ALL);
 204
 205         /* Power/battery status might have changed */
 206         battery_status_changed();
 207         ac_status_changed();
 208
 209         return 0;
 210 }
 211
 212 static SIMPLE_DEV_PM_OPS(xo15_sci_pm, NULL, xo15_sci_resume);
 213
 214 static const struct acpi_device_id xo15_sci_device_ids[] = {
 215         {"XO15EC", 0},
 216         {"", 0},
 217 };
 218
 219 static struct acpi_driver xo15_sci_drv = {
 220         .name = DRV_NAME,
 221         .class = XO15_SCI_CLASS,
 222         .ids = xo15_sci_device_ids,
 223         .ops = {
 224                 .add = xo15_sci_add,
 225                 .remove = xo15_sci_remove,
 226         },
 227         .drv.pm = &xo15_sci_pm,
 228 };
 229
 230 static int __init xo15_sci_init(void)
 231 {
 232         return acpi_bus_register_driver(&xo15_sci_drv);
 233 }
 234 device_initcall(xo15_sci_init);