On Fri, Aug 31, 2012 at 08:37:26PM -0400, Forest Bond wrote:
> From: Forest Bond <forest.b...@rapidrollout.com>
>
> 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.b...@rapidrollout.com>
> ---
> drivers/input/touchscreen/usbtouchscreen.c | 36
> ++++++++++++++++++++++++++++
> 1 files changed, 36 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/input/touchscreen/usbtouchscreen.c
> b/drivers/input/touchscreen/usbtouchscreen.c
> index e32709e..64b4b17 100644
> --- a/drivers/input/touchscreen/usbtouchscreen.c
> +++ b/drivers/input/touchscreen/usbtouchscreen.c
> @@ -304,6 +304,41 @@ 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;
> +}
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