static int bbswitch_pm_handler(struct notifier_block *nbp,
unsigned long event_type, void *p) {
switch (event_type) {
case PM_HIBERNATION_PREPARE:
case PM_SUSPEND_PREPARE:
dis_dev_get();
dis_before_suspend_disabled = is_card_disabled();
// enable the device before suspend to avoid the PCI config space from
// being saved incorrectly
if (dis_before_suspend_disabled)
bbswitch_on();
dis_dev_put();
break;
case PM_POST_HIBERNATION:
case PM_POST_SUSPEND:
case PM_POST_RESTORE:
// after suspend, the card is on, but if it was off before suspend,
// disable it again
if (dis_before_suspend_disabled) {
dis_dev_get();
bbswitch_off();
dis_dev_put();
}
break;
case PM_RESTORE_PREPARE:
// deliberately don't do anything as it does not occur before suspend
// nor hibernate, but before restoring a saved image. In that case,
// either PM_POST_HIBERNATION or PM_POST_RESTORE will be called
break;
}
return 0;
}
static void __exit bbswitch_exit(void) {
remove_proc_entry("bbswitch", acpi_root_dir);
dis_dev_get();
if (unload_state == CARD_ON)
bbswitch_on();
else if (unload_state == CARD_OFF)
bbswitch_off();
pr_info("Unloaded. Discrete card %s is %s\n",
dev_name(&dis_dev->dev), is_card_disabled() ? "off" : "on");
dis_dev_put();
if (nb.notifier_call)
unregister_pm_notifier(&nb);
}
static int bbswitch_write(struct file *filp, const char __user *buff,
unsigned long len, void *data) {
char cmd[8];
if (len >= sizeof(cmd)) {
printk(KERN_ERR "bbswitch: Input too large (%lu)\n", len);
return -ENOSPC;
}
if (copy_from_user(cmd, buff, len))
return -EFAULT;
if (strncmp(cmd, "OFF", 3) == 0)
bbswitch_off();
if (strncmp(cmd, "ON", 2) == 0)
bbswitch_on();
return len;
}
static ssize_t bbswitch_proc_write(struct file *fp, const char __user *buff,
size_t len, loff_t *off) {
char cmd[8];
if (len >= sizeof(cmd))
len = sizeof(cmd) - 1;
if (copy_from_user(cmd, buff, len))
return -EFAULT;
dis_dev_get();
if (strncmp(cmd, "OFF", 3) == 0)
bbswitch_off();
if (strncmp(cmd, "ON", 2) == 0)
bbswitch_on();
dis_dev_put();
return len;
}
static int __init bbswitch_init(void) {
struct proc_dir_entry *acpi_entry;
struct pci_dev *pdev = NULL;
acpi_handle igd_handle = NULL;
pr_info("version %s\n", BBSWITCH_VERSION);
while ((pdev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, pdev)) != NULL) {
struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
acpi_handle handle;
int pci_class = pdev->class >> 8;
if (pci_class != PCI_CLASS_DISPLAY_VGA &&
pci_class != PCI_CLASS_DISPLAY_3D)
continue;
handle = DEVICE_ACPI_HANDLE(&pdev->dev);
if (!handle) {
pr_warn("cannot find ACPI handle for VGA device %s\n",
dev_name(&pdev->dev));
continue;
}
acpi_get_name(handle, ACPI_FULL_PATHNAME, &buf);
if (pdev->vendor == PCI_VENDOR_ID_INTEL) {
igd_handle = handle;
pr_info("Found integrated VGA device %s: %s\n",
dev_name(&pdev->dev), (char *)buf.pointer);
} else {
dis_dev = pdev;
dis_handle = handle;
pr_info("Found discrete VGA device %s: %s\n",
dev_name(&pdev->dev), (char *)buf.pointer);
}
kfree(buf.pointer);
}
if (dis_dev == NULL) {
pr_err("No discrete VGA device found\n");
return -ENODEV;
}
if (!skip_optimus_dsm &&
has_dsm_func(acpi_optimus_dsm_muid, 0x100, 0x1A)) {
dsm_type = DSM_TYPE_OPTIMUS;
pr_info("detected an Optimus _DSM function\n");
} else if (has_dsm_func(acpi_nvidia_dsm_muid, 0x102, 0x3)) {
dsm_type = DSM_TYPE_NVIDIA;
pr_info("detected a nVidia _DSM function\n");
} else {
/* At least two Acer machines are known to use the intel ACPI handle
* with the legacy nvidia DSM */
dis_handle = igd_handle;
if (dis_handle && has_dsm_func(acpi_nvidia_dsm_muid, 0x102, 0x3)) {
dsm_type = DSM_TYPE_NVIDIA;
pr_info("detected a nVidia _DSM function on the"
" integrated video card\n");
} else {
pr_err("No suitable _DSM call found.\n");
return -ENODEV;
}
}
acpi_entry = proc_create("bbswitch", 0664, acpi_root_dir, &bbswitch_fops);
if (acpi_entry == NULL) {
pr_err("Couldn't create proc entry\n");
return -ENOMEM;
}
dis_dev_get();
if (!is_card_disabled()) {
/* We think the card is enabled, so ensure the kernel does as well */
if (pci_enable_device(dis_dev))
pr_warn("failed to enable %s\n", dev_name(&dis_dev->dev));
}
if (load_state == CARD_ON)
bbswitch_on();
else if (load_state == CARD_OFF)
bbswitch_off();
pr_info("Succesfully loaded. Discrete card %s is %s\n",
dev_name(&dis_dev->dev), is_card_disabled() ? "off" : "on");
dis_dev_put();
register_pm_notifier(&nb);
return 0;
}