From: Paul Walmsley <[EMAIL PROTECTED]>

Add internal support for dynamically-allocated HID quirks, "equirks"
(for "extra quirks").  Includes several functions to add/modify quirks
from the list.  This code is used by the next patch to implement quirk
modification upon module load.


Signed-off-by: Paul Walmsley <[EMAIL PROTECTED]>

---
 drivers/usb/input/hid-quirks.c |  147 +++++++++++++++++++++++++++++++++++++++--
 include/linux/hid-quirks.h     |    2
 2 files changed, 145 insertions(+), 4 deletions(-)

Index: dev/drivers/usb/input/hid-quirks.c
===================================================================
--- dev.orig/drivers/usb/input/hid-quirks.c
+++ dev/drivers/usb/input/hid-quirks.c
@@ -39,6 +39,8 @@
 #include "usbhid.h"

 static struct hid_blacklist *usbhid_exists_squirk(const u16 idVendor, const 
u16 idProduct);
+static struct hid_blacklist *usbhid_exists_equirk(const u16 idVendor, const 
u16 idProduct);
+static void usbhid_remove_all_equirks(void);


 #define USB_VENDOR_ID_PANJIT           0x134c
@@ -455,6 +457,16 @@ static struct hid_blacklist {
 };


+/* Extra HID quirks list - specified at runtime  */
+struct quirks_list_struct {
+        struct hid_blacklist hid_bl_item;
+        struct list_head node;
+};
+
+static LIST_HEAD(equirks_list);
+static DECLARE_RWSEM(equirks_rwsem);
+
+
 /**
  * usbhid_lookup_any_quirk: return any quirks associated with a USB HID device
  * @idVendor: the 16-bit USB vendor ID, in native byteorder
@@ -480,10 +492,17 @@ u32 usbhid_lookup_any_quirk(const u16 id
                    idProduct <= USB_DEVICE_ID_CODEMERCS_IOW_LAST)
                        return 0;

-       ble = usbhid_exists_squirk(idVendor, idProduct);
-       if (ble)
-               quirks = ble->quirks;
-
+       down_read(&equirks_rwsem);
+
+       ble = usbhid_exists_equirk(idVendor, idProduct);
+       if (!ble)
+               ble = usbhid_exists_squirk(idVendor, idProduct);
+
+       if (ble)
+               quirks = ble->quirks;
+
+       up_read(&equirks_rwsem);
+
        return quirks;
 }

@@ -519,3 +538,123 @@ static struct hid_blacklist *usbhid_exis
        return ble;
 }

+
+/* Runtime ("extra") quirks manipulation functions */
+
+/**
+ * usbhid_exists_equirk: find any extra quirks for a USB HID device
+ * @idVendor: the 16-bit USB vendor ID, in native byteorder
+ * @idProduct: the 16-bit USB product ID, in native byteorder
+ *
+ * Description:
+ *         Scans equirks_list for a matching extra quirk and returns
+ *         the pointer to the relevant struct hid_blacklist if found.
+ *         Must be called with a read lock held on equirks_rwsem.
+ *
+ * Returns: NULL if no quirk found, struct hid_blacklist * if found.
+ */
+static struct hid_blacklist *usbhid_exists_equirk(const u16 idVendor,
+                                                 const u16 idProduct)
+{
+       struct quirks_list_struct *q;
+       struct hid_blacklist *ble = NULL;
+
+       WARN_ON(idVendor == 0);
+
+        list_for_each_entry(q, &equirks_list, node) {
+               if (q->hid_bl_item.idVendor == idVendor &&
+                   q->hid_bl_item.idProduct == idProduct) {
+                       ble = &q->hid_bl_item;
+                       break;
+               }
+        }
+
+       if (ble != NULL)
+               dbg("Found extra quirk 0x%x for USB HID vendor 0x%hx prod 
0x%hx\n",
+                   ble->quirks, ble->idVendor,  ble->idProduct);
+
+       return ble;
+}
+
+
+/**
+ * usbhid_modify_equirk: add/replace a HID quirk
+ * @idVendor: the 16-bit USB vendor ID, in native byteorder
+ * @idProduct: the 16-bit USB product ID, in native byteorder
+ * @quirks: the u32 quirks value to add/replace
+ *
+ * Description:
+ *         If an extra quirk exists in memory for this (idVendor,
+ *         idProduct) pair, replace its quirks value with what was
+ *         provided.  Otherwise, add the quirk to the extra quirks list.
+ *
+ * Returns: 0 OK, -error on failure.
+ */
+int usbhid_modify_equirk(const u16 idVendor, const u16 idProduct,
+                        const u32 quirks)
+{
+       struct quirks_list_struct *q_new, *q;
+       int list_edited = 0;
+
+       if (!idVendor) {
+               dbg("Cannot add a quirk with idVendor = 0");
+               return -EINVAL;
+       }
+
+       q_new = kmalloc(sizeof(struct quirks_list_struct), GFP_KERNEL);
+       if (!q_new) {
+               dbg("Could not allocate quirks_list_struct");
+               return -ENOMEM;
+       }
+
+       q_new->hid_bl_item.idVendor = idVendor;
+       q_new->hid_bl_item.idProduct = idProduct;
+       q_new->hid_bl_item.quirks = quirks;
+
+       down_write(&equirks_rwsem);
+
+       list_for_each_entry(q, &equirks_list, node) {
+
+               if (q->hid_bl_item.idVendor == idVendor &&
+                   q->hid_bl_item.idProduct == idProduct) {
+
+                       list_replace(&q->node, &q_new->node);
+                       kfree(q);
+                       list_edited = 1;
+                       break;
+
+               }
+
+       }
+
+       if (!list_edited)
+               list_add_tail(&q_new->node, &equirks_list);
+
+       up_write(&equirks_rwsem);
+
+       return 0;
+}
+
+
+/**
+ * usbhid_remove_all_equirks: remove all runtime HID quirks from memory
+ *
+ * Description:
+ *         Free all memory associated with extra quirks - called before
+ *         module unload.
+ *
+ */
+static void usbhid_remove_all_equirks(void)
+{
+       struct quirks_list_struct *q, *temp;
+
+       down_write(&equirks_rwsem);
+       list_for_each_entry_safe(q, temp, &equirks_list, node) {
+               list_del(&q->node);
+               kfree(q);
+       }
+       up_write(&equirks_rwsem);
+
+}
+
+
Index: dev/include/linux/hid-quirks.h
===================================================================
--- dev.orig/include/linux/hid-quirks.h
+++ dev/include/linux/hid-quirks.h
@@ -30,6 +30,8 @@

 u32 usbhid_lookup_any_quirk(const u16 idVendor, const u16 idProduct);

+int usbhid_modify_equirk(const u16 idVendor, const u16 idProduct, const u32 
quirks);
+


 #endif /* __HID_QUIRKS_H */

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