eeepc-wmi: add hotplug code for Eeepc 1000H

Implement wireless like hotplug handling (code stolen from eeepc-laptop).

Reminder: on some models rfkill is implemented 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 platform driver.

Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

diff --git a/drivers/platform/x86/eeepc-wmi.c b/drivers/platform/x86/eeepc-wmi.c
index 0d8217d1478028071859ba1a503ba226b3cb33a0..01bc2b3da98a95ee123423de905144a99bd03e09 100644 (file)
--- a/drivers/platform/x86/eeepc-wmi.c
+++ b/drivers/platform/x86/eeepc-wmi.c
@@ -37,9 +37,12 @@
 #include <linux/backlight.h>
 #include <linux/leds.h>
 #include <linux/rfkill.h>
+#include <linux/pci.h>
+#include <linux/pci_hotplug.h>
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
 #include <linux/platform_device.h>
+#include <linux/dmi.h>
 #include <acpi/acpi_bus.h>
 #include <acpi/acpi_drivers.h>
 
@@ -72,6 +75,14 @@ MODULE_ALIAS("wmi:"EEEPC_WMI_MGMT_GUID);
 #define EEEPC_WMI_DEVID_BLUETOOTH      0x00010013
 #define EEEPC_WMI_DEVID_WWAN3G         0x00010019
 
+static bool hotplug_wireless;
+
+module_param(hotplug_wireless, bool, 0444);
+MODULE_PARM_DESC(hotplug_wireless,
+                "Enable hotplug for wireless device. "
+                "If your laptop needs that, please report to "
+                "acpi4asus-user@lists.sourceforge.net.");
+
 static const struct key_entry eeepc_wmi_keymap[] = {
        /* Sleep already handled via generic ACPI code */
        { KE_IGNORE, NOTIFY_BRNDOWN_MIN, { KEY_BRIGHTNESSDOWN } },
@@ -109,6 +120,8 @@ struct eeepc_wmi_debug {
 };
 
 struct eeepc_wmi {
+       bool hotplug_wireless;
+
        struct input_dev *inputdev;
        struct backlight_device *backlight_device;
        struct platform_device *platform_device;
@@ -122,6 +135,9 @@ struct eeepc_wmi {
        struct rfkill *bluetooth_rfkill;
        struct rfkill *wwan3g_rfkill;
 
+       struct hotplug_slot *hotplug_slot;
+       struct mutex hotplug_lock;
+
        struct eeepc_wmi_debug debug;
 };
 
@@ -177,7 +193,8 @@ static acpi_status eeepc_wmi_get_devstate(u32 dev_id, u32 *retval)
        u32 tmp;
 
        status = wmi_evaluate_method(EEEPC_WMI_MGMT_GUID,
-                       1, EEEPC_WMI_METHODID_DSTS, &input, &output);
+                                    1, EEEPC_WMI_METHODID_DSTS,
+                                    &input, &output);
 
        if (ACPI_FAILURE(status))
                return status;
@@ -333,6 +350,206 @@ static void eeepc_wmi_led_exit(struct eeepc_wmi *eeepc)
                destroy_workqueue(eeepc->led_workqueue);
 }
 
+/*
+ * PCI hotplug (for wlan rfkill)
+ */
+static bool eeepc_wlan_rfkill_blocked(struct eeepc_wmi *eeepc)
+{
+       u32 retval;
+       acpi_status status;
+
+       status = eeepc_wmi_get_devstate(EEEPC_WMI_DEVID_WLAN, &retval);
+
+       if (ACPI_FAILURE(status))
+               return false;
+
+       return !(retval & 0x1);
+}
+
+static void eeepc_rfkill_hotplug(struct eeepc_wmi *eeepc)
+{
+       struct pci_dev *dev;
+       struct pci_bus *bus;
+       bool blocked = eeepc_wlan_rfkill_blocked(eeepc);
+       bool absent;
+       u32 l;
+
+       if (eeepc->wlan_rfkill)
+               rfkill_set_sw_state(eeepc->wlan_rfkill, blocked);
+
+       mutex_lock(&eeepc->hotplug_lock);
+
+       if (eeepc->hotplug_slot) {
+               bus = pci_find_bus(0, 1);
+               if (!bus) {
+                       pr_warning("Unable to find PCI bus 1?\n");
+                       goto out_unlock;
+               }
+
+               if (pci_bus_read_config_dword(bus, 0, PCI_VENDOR_ID, &l)) {
+                       pr_err("Unable to read PCI config space?\n");
+                       goto out_unlock;
+               }
+               absent = (l == 0xffffffff);
+
+               if (blocked != absent) {
+                       pr_warning("BIOS says wireless lan is %s, "
+                                       "but the pci device is %s\n",
+                               blocked ? "blocked" : "unblocked",
+                               absent ? "absent" : "present");
+                       pr_warning("skipped wireless hotplug as probably "
+                                       "inappropriate for this model\n");
+                       goto out_unlock;
+               }
+
+               if (!blocked) {
+                       dev = pci_get_slot(bus, 0);
+                       if (dev) {
+                               /* Device already present */
+                               pci_dev_put(dev);
+                               goto out_unlock;
+                       }
+                       dev = pci_scan_single_device(bus, 0);
+                       if (dev) {
+                               pci_bus_assign_resources(bus);
+                               if (pci_bus_add_device(dev))
+                                       pr_err("Unable to hotplug wifi\n");
+                       }
+               } else {
+                       dev = pci_get_slot(bus, 0);
+                       if (dev) {
+                               pci_remove_bus_device(dev);
+                               pci_dev_put(dev);
+                       }
+               }
+       }
+
+out_unlock:
+       mutex_unlock(&eeepc->hotplug_lock);
+}
+
+static void eeepc_rfkill_notify(acpi_handle handle, u32 event, void *data)
+{
+       struct eeepc_wmi *eeepc = data;
+
+       if (event != ACPI_NOTIFY_BUS_CHECK)
+               return;
+
+       eeepc_rfkill_hotplug(eeepc);
+}
+
+static int eeepc_register_rfkill_notifier(struct eeepc_wmi *eeepc,
+                                         char *node)
+{
+       acpi_status status;
+       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,
+                                                    eeepc);
+               if (ACPI_FAILURE(status))
+                       pr_warning("Failed to register notify on %s\n", node);
+       } else
+               return -ENODEV;
+
+       return 0;
+}
+
+static void eeepc_unregister_rfkill_notifier(struct eeepc_wmi *eeepc,
+                                            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))
+                       pr_err("Error removing rfkill notify handler %s\n",
+                               node);
+       }
+}
+
+static int eeepc_get_adapter_status(struct hotplug_slot *hotplug_slot,
+                                   u8 *value)
+{
+       u32 retval;
+       acpi_status status;
+
+       status = eeepc_wmi_get_devstate(EEEPC_WMI_DEVID_WLAN, &retval);
+
+       if (ACPI_FAILURE(status))
+               return -EIO;
+
+       if (!retval || retval == 0x00060000)
+               return -ENODEV;
+       else
+               *value = (retval & 0x1);
+
+       return 0;
+}
+
+static void eeepc_cleanup_pci_hotplug(struct hotplug_slot *hotplug_slot)
+{
+       kfree(hotplug_slot->info);
+       kfree(hotplug_slot);
+}
+
+static struct hotplug_slot_ops eeepc_hotplug_slot_ops = {
+       .owner = THIS_MODULE,
+       .get_adapter_status = eeepc_get_adapter_status,
+       .get_power_status = eeepc_get_adapter_status,
+};
+
+static int eeepc_setup_pci_hotplug(struct eeepc_wmi *eeepc)
+{
+       int ret = -ENOMEM;
+       struct pci_bus *bus = pci_find_bus(0, 1);
+
+       if (!bus) {
+               pr_err("Unable to find wifi PCI bus\n");
+               return -ENODEV;
+       }
+
+       eeepc->hotplug_slot = kzalloc(sizeof(struct hotplug_slot), GFP_KERNEL);
+       if (!eeepc->hotplug_slot)
+               goto error_slot;
+
+       eeepc->hotplug_slot->info = kzalloc(sizeof(struct hotplug_slot_info),
+                                           GFP_KERNEL);
+       if (!eeepc->hotplug_slot->info)
+               goto error_info;
+
+       eeepc->hotplug_slot->private = eeepc;
+       eeepc->hotplug_slot->release = &eeepc_cleanup_pci_hotplug;
+       eeepc->hotplug_slot->ops = &eeepc_hotplug_slot_ops;
+       eeepc_get_adapter_status(eeepc->hotplug_slot,
+                                &eeepc->hotplug_slot->info->adapter_status);
+
+       ret = pci_hp_register(eeepc->hotplug_slot, bus, 0, "eeepc-wifi");
+       if (ret) {
+               pr_err("Unable to register hotplug slot - %d\n", ret);
+               goto error_register;
+       }
+
+       return 0;
+
+error_register:
+       kfree(eeepc->hotplug_slot->info);
+error_info:
+       kfree(eeepc->hotplug_slot);
+       eeepc->hotplug_slot = NULL;
+error_slot:
+       return ret;
+}
+
 /*
  * Rfkill devices
  */
@@ -404,11 +621,22 @@ static int eeepc_new_rfkill(struct eeepc_wmi *eeepc,
 
 static void eeepc_wmi_rfkill_exit(struct eeepc_wmi *eeepc)
 {
+       eeepc_unregister_rfkill_notifier(eeepc, "\\_SB.PCI0.P0P5");
+       eeepc_unregister_rfkill_notifier(eeepc, "\\_SB.PCI0.P0P6");
+       eeepc_unregister_rfkill_notifier(eeepc, "\\_SB.PCI0.P0P7");
        if (eeepc->wlan_rfkill) {
                rfkill_unregister(eeepc->wlan_rfkill);
                rfkill_destroy(eeepc->wlan_rfkill);
                eeepc->wlan_rfkill = NULL;
        }
+       /*
+        * Refresh pci hotplug in case the rfkill state was changed after
+        * eeepc_unregister_rfkill_notifier()
+        */
+       eeepc_rfkill_hotplug(eeepc);
+       if (eeepc->hotplug_slot)
+               pci_hp_deregister(eeepc->hotplug_slot);
+
        if (eeepc->bluetooth_rfkill) {
                rfkill_unregister(eeepc->bluetooth_rfkill);
                rfkill_destroy(eeepc->bluetooth_rfkill);
@@ -425,6 +653,8 @@ static int eeepc_wmi_rfkill_init(struct eeepc_wmi *eeepc)
 {
        int result = 0;
 
+       mutex_init(&eeepc->hotplug_lock);
+
        result = eeepc_new_rfkill(eeepc, &eeepc->wlan_rfkill,
                                  "eeepc-wlan", RFKILL_TYPE_WLAN,
                                  EEEPC_WMI_DEVID_WLAN);
@@ -446,6 +676,23 @@ static int eeepc_wmi_rfkill_init(struct eeepc_wmi *eeepc)
        if (result && result != -ENODEV)
                goto exit;
 
+       result = eeepc_setup_pci_hotplug(eeepc);
+       /*
+        * If we get -EBUSY then something else is handling the PCI hotplug -
+        * don't fail in this case
+        */
+       if (result == -EBUSY)
+               result = 0;
+
+       eeepc_register_rfkill_notifier(eeepc, "\\_SB.PCI0.P0P5");
+       eeepc_register_rfkill_notifier(eeepc, "\\_SB.PCI0.P0P6");
+       eeepc_register_rfkill_notifier(eeepc, "\\_SB.PCI0.P0P7");
+       /*
+        * Refresh pci hotplug in case the rfkill state was changed during
+        * setup.
+        */
+       eeepc_rfkill_hotplug(eeepc);
+
 exit:
        if (result && result != -ENODEV)
                eeepc_wmi_rfkill_exit(eeepc);
@@ -771,6 +1018,28 @@ error_debugfs:
 /*
  * WMI Driver
  */
+static void eeepc_dmi_check(struct eeepc_wmi *eeepc)
+{
+       const char *model;
+
+       model = dmi_get_system_info(DMI_PRODUCT_NAME);
+       if (!model)
+               return;
+
+       /*
+        * Whitelist for wlan hotplug
+        *
+        * Eeepc 1000H needs the current hotplug code to handle
+        * Fn+F2 correctly. We may add other Eeepc here later, but
+        * it seems that most of the laptops supported by eeepc-wmi
+        * don't need to be on this list
+        */
+       if (strcmp(model, "1000H") == 0) {
+               eeepc->hotplug_wireless = true;
+               pr_info("wlan hotplug enabled\n");
+       }
+}
+
 static struct platform_device * __init eeepc_wmi_add(void)
 {
        struct eeepc_wmi *eeepc;
@@ -781,6 +1050,9 @@ static struct platform_device * __init eeepc_wmi_add(void)
        if (!eeepc)
                return ERR_PTR(-ENOMEM);
 
+       eeepc->hotplug_wireless = hotplug_wireless;
+       eeepc_dmi_check(eeepc);
+
        /*
         * Register the platform device first.  It is used as a parent for the
         * sub-devices below.