eeepc-laptop: Implement rfkill hotplugging in eeepc-laptop

The Eee implements rfkill by logically unplugging the wireless card from the
PCI bus. Despite sending ACPI notifications, this does not appear to be
implemented using standard ACPI hotplug - nor does the firmware provide the
_OSC method required to support native PCIe hotplug. The only sensible choice
appears to be to handle the hotplugging directly in the eeepc-laptop driver.
Tested successfully on a 700, 900 and 901.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 83 insertions, 0 deletions

diff --git a/drivers/platform/x86/eeepc-laptop.c b/drivers/platform/x86/eeepc-laptop.c
index 21e5206ed28b..66655d2b4ce9 100644
--- a/drivers/platform/x86/eeepc-laptop.c
+++ b/drivers/platform/x86/eeepc-laptop.c
@@ -30,6 +30,7 @@
 #include <linux/uaccess.h>
 #include <linux/input.h>
 #include <linux/rfkill.h>
+#include <linux/pci.h>
 
 #define EEEPC_LAPTOP_VERSION    "0.1"
 
@@ -517,6 +518,41 @@ static void notify_brn(void)
         bd->props.brightness = read_brightness(bd);
 }
 
+static void eeepc_rfkill_notify(acpi_handle handle, u32 event, void *data)
+{
+        struct pci_dev *dev;
+        struct pci_bus *bus = pci_find_bus(0, 1);
+
+        if (event != ACPI_NOTIFY_BUS_CHECK)
+                return;
+
+        if (!bus) {
+                printk(EEEPC_WARNING "Unable to find PCI bus 1?\n");
+                return;
+        }
+
+        if (get_acpi(CM_ASL_WLAN) == 1) {
+                dev = pci_get_slot(bus, 0);
+                if (dev) {
+                        /* Device already present */
+                        pci_dev_put(dev);
+                        return;
+                }
+                dev = pci_scan_single_device(bus, 0);
+                if (dev) {
+                        pci_bus_assign_resources(bus);
+                        if (pci_bus_add_device(dev))
+                                printk(EEEPC_ERR "Unable to hotplug wifi\n");
+                }
+        } else {
+                dev = pci_get_slot(bus, 0);
+                if (dev) {
+                        pci_remove_bus_device(dev);
+                        pci_dev_put(dev);
+                }
+        }
+}
+
 static void eeepc_hotk_notify(acpi_handle handle, u32 event, void *data)
 {
         static struct key_entry *key;
@@ -543,6 +579,45 @@ static void eeepc_hotk_notify(acpi_handle handle, u32 event, void *data)
         }
 }
 
+static int eeepc_register_rfkill_notifier(char *node)
+{
+        acpi_status status = AE_OK;
+        acpi_handle handle;
+
+        status = acpi_get_handle(NULL, node, &handle);
+
+        if (ACPI_SUCCESS(status)) {
+                status = acpi_install_notify_handler(handle,
+                                                     ACPI_SYSTEM_NOTIFY,
+                                                     eeepc_rfkill_notify,
+                                                     NULL);
+                if (ACPI_FAILURE(status))
+                        printk(EEEPC_WARNING
+                               "Failed to register notify on %s\n", node);
+        } else
+                return -ENODEV;
+
+        return 0;
+}
+
+static void eeepc_unregister_rfkill_notifier(char *node)
+{
+        acpi_status status = AE_OK;
+        acpi_handle handle;
+
+        status = acpi_get_handle(NULL, node, &handle);
+
+        if (ACPI_SUCCESS(status)) {
+                status = acpi_remove_notify_handler(handle,
+                                                     ACPI_SYSTEM_NOTIFY,
+                                                     eeepc_rfkill_notify);
+                if (ACPI_FAILURE(status))
+                        printk(EEEPC_ERR
+                               "Error removing rfkill notify handler %s\n",
+                                node);
+        }
+}
+
 static int eeepc_hotk_add(struct acpi_device *device)
 {
         acpi_status status = AE_OK;
@@ -622,6 +697,10 @@ static int eeepc_hotk_add(struct acpi_device *device)
                 if (result)
                         goto bluetooth_fail;
         }
+
+        eeepc_register_rfkill_notifier("\\_SB.PCI0.P0P6");
+        eeepc_register_rfkill_notifier("\\_SB.PCI0.P0P7");
+
         return 0;
 
  bluetooth_fail:
@@ -649,6 +728,10 @@ static int eeepc_hotk_remove(struct acpi_device *device, int type)
                                             eeepc_hotk_notify);
         if (ACPI_FAILURE(status))
                 printk(EEEPC_ERR "Error removing notify handler\n");
+
+        eeepc_unregister_rfkill_notifier("\\_SB.PCI0.P0P6");
+        eeepc_unregister_rfkill_notifier("\\_SB.PCI0.P0P7");
+
         kfree(ehotk);
         return 0;
 }