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authorForest Bond <forest.bond@rapidrollout.com>2012-09-05 07:27:37 +0400
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2012-09-05 09:17:56 +0400
commit037a833ed05a86d01ea27a2c32043b86c549be1b (patch)
treef8350bd3b8f43218374342544a1427d1e66a9bb7 /drivers/input/touchscreen/usbtouchscreen.c
parent6f4d0382e2a6d27045e223d8c452659477826650 (diff)
downloadlinux-037a833ed05a86d01ea27a2c32043b86c549be1b.tar.xz
Input: usbtouchscreen - initialize eGalax devices
Certain eGalax devices expose an interface with class HID and protocol None. Some work with usbhid and some work with usbtouchscreen, but there is no easy way to differentiate. Sending an eGalax diagnostic packet seems to kick them all into using the right protocol for usbtouchscreen, so we can continue to bind them all there (as opposed to handing some off to usbhid). This fixes a regression for devices that were claimed by (and worked with) usbhid prior to commit 139ebe8dc80dd74cb2ac9f5603d18fbf5cff049f ("Input: usbtouchscreen - fix eGalax HID ignoring"), which made usbtouchscreen claim them instead. With this patch they will still be claimed by usbtouchscreen, but they will actually report events usbtouchscreen can understand. Note that these devices will be limited to the usbtouchscreen feature set so e.g. dual touch features are not supported. I have the distinct pleasure of needing to support devices of both types and have tested accordingly. Signed-off-by: Forest Bond <forest.bond@rapidrollout.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'drivers/input/touchscreen/usbtouchscreen.c')
-rw-r--r--drivers/input/touchscreen/usbtouchscreen.c40
1 files changed, 40 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/usbtouchscreen.c b/drivers/input/touchscreen/usbtouchscreen.c
index e32709e0dd65..721fdb3597ca 100644
--- a/drivers/input/touchscreen/usbtouchscreen.c
+++ b/drivers/input/touchscreen/usbtouchscreen.c
@@ -304,6 +304,45 @@ static int e2i_read_data(struct usbtouch_usb *dev, unsigned char *pkt)
#define EGALAX_PKT_TYPE_REPT 0x80
#define EGALAX_PKT_TYPE_DIAG 0x0A
+static int egalax_init(struct usbtouch_usb *usbtouch)
+{
+ int ret, i;
+ unsigned char *buf;
+ struct usb_device *udev = interface_to_usbdev(usbtouch->interface);
+
+ /*
+ * An eGalax diagnostic packet kicks the device into using the right
+ * protocol. We send a "check active" packet. The response will be
+ * read later and ignored.
+ */
+
+ buf = kmalloc(3, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ buf[0] = EGALAX_PKT_TYPE_DIAG;
+ buf[1] = 1; /* length */
+ buf[2] = 'A'; /* command - check active */
+
+ for (i = 0; i < 3; i++) {
+ ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
+ 0,
+ USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+ 0, 0, buf, 3,
+ USB_CTRL_SET_TIMEOUT);
+ if (ret >= 0) {
+ ret = 0;
+ break;
+ }
+ if (ret != -EPIPE)
+ break;
+ }
+
+ kfree(buf);
+
+ return ret;
+}
+
static int egalax_read_data(struct usbtouch_usb *dev, unsigned char *pkt)
{
if ((pkt[0] & EGALAX_PKT_TYPE_MASK) != EGALAX_PKT_TYPE_REPT)
@@ -1056,6 +1095,7 @@ static struct usbtouch_device_info usbtouch_dev_info[] = {
.process_pkt = usbtouch_process_multi,
.get_pkt_len = egalax_get_pkt_len,
.read_data = egalax_read_data,
+ .init = egalax_init,
},
#endif