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Commit 8cef9082 authored by Paul Walmsley's avatar Paul Walmsley Committed by Jiri Kosina
Browse files

USB HID: add support for dynamically-created quirks 



Add internal support for dynamically-allocated HID quirks, "dquirks"
(for "dynamic 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: default avatarPaul Walmsley <paul@booyaka.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent 8222fbe6

drivers/hid/usbhid/hid-quirks.c

+149 −14
Original line number Diff line number Diff line
@@ -447,6 +447,136 @@ static const struct hid_blacklist { 


	{ 0, 0 }

};



/* Dynamic HID quirks list - specified at runtime */

struct quirks_list_struct {

	struct hid_blacklist hid_bl_item;

	struct list_head node;

};



static LIST_HEAD(dquirks_list);

static DECLARE_RWSEM(dquirks_rwsem);



/* Runtime ("dynamic") quirks manipulation functions */



/**

 * usbhid_exists_dquirk: find any dynamic 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 dquirks_list for a matching dynamic quirk and returns

 *         the pointer to the relevant struct hid_blacklist if found.

 *         Must be called with a read lock held on dquirks_rwsem.

 *

 * Returns: NULL if no quirk found, struct hid_blacklist * if found.

 */

static struct hid_blacklist *usbhid_exists_dquirk(const u16 idVendor,

		const u16 idProduct)

{

	struct quirks_list_struct *q;

	struct hid_blacklist *bl_entry = NULL;



	WARN_ON(idVendor == 0);



	list_for_each_entry(q, &dquirks_list, node) {

		if (q->hid_bl_item.idVendor == idVendor &&

				q->hid_bl_item.idProduct == idProduct) {

			bl_entry = &q->hid_bl_item;

			break;

		}

	}



	if (bl_entry != NULL)

		dbg("Found dynamic quirk 0x%x for USB HID vendor 0x%hx prod 0x%hx\n",

				bl_entry->quirks, bl_entry->idVendor,

				bl_entry->idProduct);



	return bl_entry;

}





/**

 * usbhid_modify_dquirk: 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 dynamic quirk exists in memory for this (idVendor,

 *         idProduct) pair, replace its quirks value with what was

 *         provided.  Otherwise, add the quirk to the dynamic quirks list.

 *

 * Returns: 0 OK, -error on failure.

 */

int usbhid_modify_dquirk(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(&dquirks_rwsem);



	list_for_each_entry(q, &dquirks_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, &dquirks_list);



	up_write(&dquirks_rwsem);



	return 0;

}





/**

 * usbhid_remove_all_dquirks: remove all runtime HID quirks from memory

 *

 * Description:

 *         Free all memory associated with dynamic quirks - called before

 *         module unload.

 *

 */

static void usbhid_remove_all_dquirks(void)

{

	struct quirks_list_struct *q, *temp;



	down_write(&dquirks_rwsem);

	list_for_each_entry_safe(q, temp, &dquirks_list, node) {

		list_del(&q->node);

		kfree(q);

	}

	up_write(&dquirks_rwsem);



}





/**

 * usbhid_exists_squirk: return any static quirks for a USB HID device

 * @idVendor: the 16-bit USB vendor ID, in native byteorder
@@ -502,9 +632,14 @@ u32 usbhid_lookup_quirk(const u16 idVendor, const u16 idProduct) 
				idProduct <= USB_DEVICE_ID_CODEMERCS_IOW_LAST)

			return HID_QUIRK_IGNORE;



	down_read(&dquirks_rwsem);

	bl_entry = usbhid_exists_dquirk(idVendor, idProduct);

	if (!bl_entry)

		bl_entry = usbhid_exists_squirk(idVendor, idProduct);

	if (bl_entry)

		quirks = bl_entry->quirks;

	up_read(&dquirks_rwsem);



	return quirks;

}

include/linux/hid.h

+1 −0
Original line number Diff line number Diff line
@@ -496,6 +496,7 @@ void hid_free_device(struct hid_device *device); 
struct hid_device *hid_parse_report(__u8 *start, unsigned size);



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

int usbhid_modify_dquirk(const u16 idVendor, const u16 idProduct, const u32 quirks);



#ifdef CONFIG_HID_FF

int hid_ff_init(struct hid_device *hid);