USB HID: add 'quirks' module parameter

Add a 'quirks' module parameter for the usbhid module, so users can
add or modify quirks at module load time.

Signed-off-by: Paul Walmsley <paul@booyaka.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

3 files changed, 59 insertions, 0 deletions

diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index bf118c05a621..91d610358d57 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -53,6 +53,13 @@ static unsigned int hid_mousepoll_interval;
 module_param_named(mousepoll, hid_mousepoll_interval, uint, 0644);
 MODULE_PARM_DESC(mousepoll, "Polling interval of mice");
 
+/* Quirks specified at module load time */
+static char *quirks_param[MAX_USBHID_BOOT_QUIRKS] = { [ 0 ... (MAX_USBHID_BOOT_QUIRKS - 1) ] = NULL };
+module_param_array_named(quirks, quirks_param, charp, NULL, 0444);
+MODULE_PARM_DESC(quirks, "Add/modify USB HID quirks by specifying "
+                " quirks=vendorID:productID:quirks"
+                " where vendorID, productID, and quirks are all in"
+                " 0x-prefixed hex");
 /*
  * Input submission and I/O error handler.
  */
@@ -1072,6 +1079,9 @@ static struct usb_driver hid_driver = {
 static int __init hid_init(void)
 {
         int retval;
+        retval = usbhid_quirks_init(quirks_param);
+        if (retval)
+                goto usbhid_quirks_init_fail;
         retval = hiddev_init();
         if (retval)
                 goto hiddev_init_fail;
@@ -1084,6 +1094,8 @@ static int __init hid_init(void)
 usb_register_fail:
         hiddev_exit();
 hiddev_init_fail:
+        usbhid_quirks_exit();
+usbhid_quirks_init_fail:
         return retval;
 }
 
@@ -1091,6 +1103,7 @@ static void __exit hid_exit(void)
 {
         usb_deregister(&hid_driver);
         hiddev_exit();
+        usbhid_quirks_exit();
 }
 
 module_init(hid_init);
diff --git a/drivers/hid/usbhid/hid-quirks.c b/drivers/hid/usbhid/hid-quirks.c
index a5fc8b5144ef..27188bd1e851 100644
--- a/drivers/hid/usbhid/hid-quirks.c
+++ b/drivers/hid/usbhid/hid-quirks.c
@@ -576,6 +576,44 @@ static void usbhid_remove_all_dquirks(void)
 
 }
 
+/** 
+ * usbhid_quirks_init: apply USB HID quirks specified at module load time
+ */
+int usbhid_quirks_init(char **quirks_param)
+{
+        u16 idVendor, idProduct;
+        u32 quirks;
+        int n = 0, m;
+
+        for (; quirks_param[n] && n < MAX_USBHID_BOOT_QUIRKS; n++) {
+
+                m = sscanf(quirks_param[n], "0x%hx:0x%hx:0x%x",
+                                &idVendor, &idProduct, &quirks);
+
+                if (m != 3 ||
+                                usbhid_modify_dquirk(idVendor, idProduct, quirks) != 0) {
+                        printk(KERN_WARNING
+                                        "Could not parse HID quirk module param %s\n",
+                                        quirks_param[n]);
+                }
+        }
+
+        return 0;
+}
+
+/**
+ * usbhid_quirks_exit: release memory associated with dynamic_quirks
+ *
+ * Description:
+ *     Release all memory associated with dynamic quirks.  Called upon
+ *     module unload.
+ *
+ * Returns: nothing
+ */
+void usbhid_quirks_exit(void)
+{
+        usbhid_remove_all_dquirks();
+}
 
 /**
  * usbhid_exists_squirk: return any static quirks for a USB HID device
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 4ba456d71f6b..37076b116ed0 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -247,6 +247,11 @@ struct hid_item {
  * HID device quirks.
  */
 
+/* 
+ * Increase this if you need to configure more HID quirks at module load time
+ */
+#define MAX_USBHID_BOOT_QUIRKS 4
+
 #define HID_QUIRK_INVERT                        0x00000001
 #define HID_QUIRK_NOTOUCH                       0x00000002
 #define HID_QUIRK_IGNORE                        0x00000004
@@ -495,8 +500,11 @@ void hid_output_report(struct hid_report *report, __u8 *data);
 void hid_free_device(struct hid_device *device);
 struct hid_device *hid_parse_report(__u8 *start, unsigned size);
 
+/* HID quirks API */
 u32 usbhid_lookup_quirk(const u16 idVendor, const u16 idProduct);
 int usbhid_modify_dquirk(const u16 idVendor, const u16 idProduct, const u32 quirks);
+int usbhid_quirks_init(char **quirks_param);
+void usbhid_quirks_exit(void);
 
 #ifdef CONFIG_HID_FF
 int hid_ff_init(struct hid_device *hid);