ACPI: autoload modules - Create ACPI alias interface

Modify modpost (file2alias.c) to add acpi*:XYZ0001: alias in modules.alias
like:
grep acpi /lib/modules/2.6.22-rc4-default/modules.alias
alias acpi*:SNY5001:* sony_laptop
alias acpi*:SNY6001:* sony_laptop
for e.g. the sony_laptop module.
This module matches against all ACPI devices with a HID or CID of SNY5001
or SNY6001

Export an uevent and modalias sysfs file containing the string:
[MODALIAS=]acpi:PNP0C0C:
additional CIDs are concatenated at the end.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 111 insertions, 45 deletions

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 6b3b8a52247..be74347d135 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -16,7 +16,7 @@ ACPI_MODULE_NAME("scan");
 extern struct acpi_device *acpi_root;
 
 #define ACPI_BUS_CLASS                  "system_bus"
-#define ACPI_BUS_HID                    "ACPI_BUS"
+#define ACPI_BUS_HID                    "LNXSYBUS"
 #define ACPI_BUS_DEVICE_NAME            "System Bus"
 
 static LIST_HEAD(acpi_device_list);
@@ -29,6 +29,62 @@ struct acpi_device_bus_id{
         unsigned int instance_no;
         struct list_head node;
 };
+
+/*
+ * Creates hid/cid(s) string needed for modalias and uevent
+ * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
+ * char *modalias: "acpi:IBM0001:ACPI0001"
+*/
+int create_modalias(struct acpi_device *acpi_dev, char *modalias, int size){
+
+        int len;
+
+        if (!acpi_dev->flags.hardware_id)
+                return -ENODEV;
+
+        len = snprintf(modalias, size, "acpi:%s:",
+                       acpi_dev->pnp.hardware_id);
+        if (len < 0 || len >= size)
+                return -EINVAL;
+        size -= len;
+
+        if (acpi_dev->flags.compatible_ids) {
+                struct acpi_compatible_id_list *cid_list;
+                int i;
+                int count;
+
+                cid_list = acpi_dev->pnp.cid_list;
+                for (i = 0; i < cid_list->count; i++) {
+                        count = snprintf(&modalias[len], size, "%s:",
+                                         cid_list->id[i].value);
+                        if (count < 0 || count >= size) {
+                                printk(KERN_ERR "acpi: %s cid[%i] exceeds event buffer size",
+                                       acpi_dev->pnp.device_name, i);
+                                break;
+                        }
+                        len += count;
+                        size -= count;
+                }
+        }
+
+        modalias[len] = '\0';
+        return len;
+}
+
+static ssize_t
+acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
+        struct acpi_device *acpi_dev = to_acpi_device(dev);
+        int len;
+
+        /* Device has no HID and no CID or string is >1024 */
+        len = create_modalias(acpi_dev, buf, 1024);
+        if (len <= 0)
+                return 0;
+        buf[len++] = '\n';
+        return len;
+}
+static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
+
 static int acpi_eject_operation(acpi_handle handle, int lockable)
 {
         struct acpi_object_list arg_list;
@@ -154,6 +210,12 @@ static int acpi_device_setup_files(struct acpi_device *dev)
                         goto end;
         }
 
+        if (dev->flags.hardware_id || dev->flags.compatible_ids){
+                result = device_create_file(&dev->dev, &dev_attr_modalias);
+                if(result)
+                        goto end;
+        }
+
         /*
          * If device has _EJ0, 'eject' file is created that is used to trigger
          * hot-removal function from userland.
@@ -178,6 +240,9 @@ static void acpi_device_remove_files(struct acpi_device *dev)
         if (ACPI_SUCCESS(status))
                 device_remove_file(&dev->dev, &dev_attr_eject);
 
+        if (dev->flags.hardware_id || dev->flags.compatible_ids)
+                device_remove_file(&dev->dev, &dev_attr_modalias);
+
         if(dev->flags.hardware_id)
                 device_remove_file(&dev->dev, &dev_attr_hid);
         if(dev->handle)
@@ -186,6 +251,37 @@ static void acpi_device_remove_files(struct acpi_device *dev)
 /* --------------------------------------------------------------------------
                         ACPI Bus operations
    -------------------------------------------------------------------------- */
+
+int acpi_match_device_ids(struct acpi_device *device,
+                          const struct acpi_device_id *ids)
+{
+        const struct acpi_device_id *id;
+
+        if (device->flags.hardware_id) {
+                for (id = ids; id->id[0]; id++) {
+                        if (!strcmp((char*)id->id, device->pnp.hardware_id))
+                                return 0;
+                }
+        }
+
+        if (device->flags.compatible_ids) {
+                struct acpi_compatible_id_list *cid_list = device->pnp.cid_list;
+                int i;
+
+                for (id = ids; id->id[0]; id++) {
+                        /* compare multiple _CID entries against driver ids */
+                        for (i = 0; i < cid_list->count; i++) {
+                                if (!strcmp((char*)id->id,
+                                            cid_list->id[i].value))
+                                        return 0;
+                        }
+                }
+        }
+
+        return -ENOENT;
+}
+EXPORT_SYMBOL(acpi_match_device_ids);
+
 static void acpi_device_release(struct device *dev)
 {
         struct acpi_device *acpi_dev = to_acpi_device(dev);
@@ -219,37 +315,19 @@ static int acpi_bus_match(struct device *dev, struct device_driver *drv)
         struct acpi_device *acpi_dev = to_acpi_device(dev);
         struct acpi_driver *acpi_drv = to_acpi_driver(drv);
 
-        return !acpi_match_ids(acpi_dev, acpi_drv->ids);
+        return !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
 }
 
 static int acpi_device_uevent(struct device *dev, char **envp, int num_envp,
-        char *buffer, int buffer_size)
+                              char *buffer, int buffer_size)
 {
         struct acpi_device *acpi_dev = to_acpi_device(dev);
-        int i = 0, length = 0, ret = 0;
-
-        if (acpi_dev->flags.hardware_id)
-                ret = add_uevent_var(envp, num_envp, &i,
-                        buffer, buffer_size, &length,
-                        "HWID=%s", acpi_dev->pnp.hardware_id);
-        if (ret)
-                return -ENOMEM;
-        if (acpi_dev->flags.compatible_ids) {
-                int j;
-                struct acpi_compatible_id_list *cid_list;
 
-                cid_list = acpi_dev->pnp.cid_list;
-
-                for (j = 0; j < cid_list->count; j++) {
-                        ret = add_uevent_var(envp, num_envp, &i, buffer,
-                                buffer_size, &length, "COMPTID=%s",
-                                cid_list->id[j].value);
-                        if (ret)
-                                return -ENOMEM;
-                }
+        strcpy(buffer, "MODALIAS=");
+        if (create_modalias(acpi_dev, buffer + 9, buffer_size - 9) > 0) {
+                envp[0] = buffer;
+                envp[1] = NULL;
         }
-
-        envp[i] = NULL;
         return 0;
 }
 
@@ -543,25 +621,6 @@ void acpi_bus_data_handler(acpi_handle handle, u32 function, void *context)
         return;
 }
 
-int acpi_match_ids(struct acpi_device *device, char *ids)
-{
-        if (device->flags.hardware_id)
-                if (strstr(ids, device->pnp.hardware_id))
-                        return 0;
-
-        if (device->flags.compatible_ids) {
-                struct acpi_compatible_id_list *cid_list = device->pnp.cid_list;
-                int i;
-
-                /* compare multiple _CID entries against driver ids */
-                for (i = 0; i < cid_list->count; i++) {
-                        if (strstr(ids, cid_list->id[i].value))
-                                return 0;
-                }
-        }
-        return -ENOENT;
-}
-
 static int acpi_bus_get_perf_flags(struct acpi_device *device)
 {
         device->performance.state = ACPI_STATE_UNKNOWN;
@@ -624,6 +683,13 @@ static int acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
         union acpi_object *package = NULL;
 
+        struct acpi_device_id button_device_ids[] = {
+                {"PNP0C0D", 0},
+                {"PNP0C0C", 0},
+                {"PNP0C0E", 0},
+                {"", 0},
+        };
+
 
         /* _PRW */
         status = acpi_evaluate_object(device->handle, "_PRW", NULL, &buffer);
@@ -643,7 +709,7 @@ static int acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
 
         device->wakeup.flags.valid = 1;
         /* Power button, Lid switch always enable wakeup */
-        if (!acpi_match_ids(device, "PNP0C0D,PNP0C0C,PNP0C0E"))
+        if (!acpi_match_device_ids(device, button_device_ids))
                 device->wakeup.flags.run_wake = 1;
 
       end: