kernel/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 <linux/acpi.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         acpi_status status;
  43
  44         status = acpi_execute_simple_method(NULL, "\\_SB.PCI0.LID.LIDW", wake_on_close);
  45         if (ACPI_FAILURE(status)) {
  46                 pr_warning(PFX "failed to set lid behavior\n");
  47                 return 1;
  48         }
  49
  50         lid_wake_on_close = wake_on_close;
  51
  52         return 0;
  53 }
  54
  55 static ssize_t
  56 lid_wake_on_close_show(struct kobject *s, struct kobj_attribute *attr, char *buf)
  57 {
  58         return sprintf(buf, "%u\n", lid_wake_on_close);
  59 }
  60
  61 static ssize_t lid_wake_on_close_store(struct kobject *s,
  62                                        struct kobj_attribute *attr,
  63                                        const char *buf, size_t n)
  64 {
  65         unsigned int val;
  66
  67         if (sscanf(buf, "%u", &val) != 1)
  68                 return -EINVAL;
  69
  70         set_lid_wake_behavior(!!val);
  71
  72         return n;
  73 }
  74
  75 static struct kobj_attribute lid_wake_on_close_attr =
  76         __ATTR(lid_wake_on_close, 0644,
  77                lid_wake_on_close_show,
  78                lid_wake_on_close_store);
  79
  80 static void battery_status_changed(void)
  81 {
  82         struct power_supply *psy = power_supply_get_by_name("olpc-battery");
  83
  84         if (psy) {
  85                 power_supply_changed(psy);
  86                 power_supply_put(psy);
  87         }
  88 }
  89
  90 static void ac_status_changed(void)
  91 {
  92         struct power_supply *psy = power_supply_get_by_name("olpc-ac");
  93
  94         if (psy) {
  95                 power_supply_changed(psy);
  96                 power_supply_put(psy);
  97         }
  98 }
  99
 100 static void process_sci_queue(void)
 101 {
 102         u16 data;
 103         int r;
 104
 105         do {
 106                 r = olpc_ec_sci_query(&data);
 107                 if (r || !data)
 108                         break;
 109
 110                 pr_debug(PFX "SCI 0x%x received\n", data);
 111
 112                 switch (data) {
 113                 case EC_SCI_SRC_BATERR:
 114                 case EC_SCI_SRC_BATSOC:
 115                 case EC_SCI_SRC_BATTERY:
 116                 case EC_SCI_SRC_BATCRIT:
 117                         battery_status_changed();
 118                         break;
 119                 case EC_SCI_SRC_ACPWR:
 120                         ac_status_changed();
 121                         break;
 122                 }
 123         } while (data);
 124
 125         if (r)
 126                 pr_err(PFX "Failed to clear SCI queue");
 127 }
 128
 129 static void process_sci_queue_work(struct work_struct *work)
 130 {
 131         process_sci_queue();
 132 }
 133
 134 static DECLARE_WORK(sci_work, process_sci_queue_work);
 135
 136 static u32 xo15_sci_gpe_handler(acpi_handle gpe_device, u32 gpe, void *context)
 137 {
 138         schedule_work(&sci_work);
 139         return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
 140 }
 141
 142 static int xo15_sci_add(struct acpi_device *device)
 143 {
 144         unsigned long long tmp;
 145         acpi_status status;
 146         int r;
 147
 148         if (!device)
 149                 return -EINVAL;
 150
 151         strcpy(acpi_device_name(device), XO15_SCI_DEVICE_NAME);
 152         strcpy(acpi_device_class(device), XO15_SCI_CLASS);
 153
 154         /* Get GPE bit assignment (EC events). */
 155         status = acpi_evaluate_integer(device->handle, "_GPE", NULL, &tmp);
 156         if (ACPI_FAILURE(status))
 157                 return -EINVAL;
 158
 159         xo15_sci_gpe = tmp;
 160         status = acpi_install_gpe_handler(NULL, xo15_sci_gpe,
 161                                           ACPI_GPE_EDGE_TRIGGERED,
 162                                           xo15_sci_gpe_handler, device);
 163         if (ACPI_FAILURE(status))
 164                 return -ENODEV;
 165
 166         dev_info(&device->dev, "Initialized, GPE = 0x%lx\n", xo15_sci_gpe);
 167
 168         r = sysfs_create_file(&device->dev.kobj, &lid_wake_on_close_attr.attr);
 169         if (r)
 170                 goto err_sysfs;
 171
 172         /* Flush queue, and enable all SCI events */
 173         process_sci_queue();
 174         olpc_ec_mask_write(EC_SCI_SRC_ALL);
 175
 176         acpi_enable_gpe(NULL, xo15_sci_gpe);
 177
 178         /* Enable wake-on-EC */
 179         if (device->wakeup.flags.valid)
 180                 device_init_wakeup(&device->dev, true);
 181
 182         return 0;
 183
 184 err_sysfs:
 185         acpi_remove_gpe_handler(NULL, xo15_sci_gpe, xo15_sci_gpe_handler);
 186         cancel_work_sync(&sci_work);
 187         return r;
 188 }
 189
 190 static int xo15_sci_remove(struct acpi_device *device)
 191 {
 192         acpi_disable_gpe(NULL, xo15_sci_gpe);
 193         acpi_remove_gpe_handler(NULL, xo15_sci_gpe, xo15_sci_gpe_handler);
 194         cancel_work_sync(&sci_work);
 195         sysfs_remove_file(&device->dev.kobj, &lid_wake_on_close_attr.attr);
 196         return 0;
 197 }
 198
 199 static int xo15_sci_resume(struct device *dev)
 200 {
 201         /* Enable all EC events */
 202         olpc_ec_mask_write(EC_SCI_SRC_ALL);
 203
 204         /* Power/battery status might have changed */
 205         battery_status_changed();
 206         ac_status_changed();
 207
 208         return 0;
 209 }
 210
 211 static SIMPLE_DEV_PM_OPS(xo15_sci_pm, NULL, xo15_sci_resume);
 212
 213 static const struct acpi_device_id xo15_sci_device_ids[] = {
 214         {"XO15EC", 0},
 215         {"", 0},
 216 };
 217
 218 static struct acpi_driver xo15_sci_drv = {
 219         .name = DRV_NAME,
 220         .class = XO15_SCI_CLASS,
 221         .ids = xo15_sci_device_ids,
 222         .ops = {
 223                 .add = xo15_sci_add,
 224                 .remove = xo15_sci_remove,
 225         },
 226         .drv.pm = &xo15_sci_pm,
 227 };
 228
 229 static int __init xo15_sci_init(void)
 230 {
 231         return acpi_bus_register_driver(&xo15_sci_drv);
 232 }
 233 device_initcall(xo15_sci_init);