Hi I currently work on an HID driver for the Nintendo Wii Remote as Bluez GSoC project. The Wii Remote (further wiimote) is a small wireless device that communicates with the host via bluetooth. It uses the HID ports but does not provide any proper HID descriptor sets and doesn't really fit into the HID class so a special driver is needed to control the device. See [1], [2] and [3] for device details if required. Since the wiimote protocol requires the host to send complex memory read/write commands to the wiimote, I need to use the raw hid interface. I use the .raw_event callback to get access to the raw input events, however, I also need to send raw events to the device. The HIDRAW driver does exactly that. It uses: ret = dev->hid_output_raw_report(dev, buf, count, report_type); However, this function may block and my HID driver, obviously, needs to send commands in atomic context. Therefore, I implemented a buffer which is sent to the device in a workqueue via hid_output_raw_report. No driver in the drivers/hid/ directory uses a workqueue, though, I can't figure out any other way to solve my problems here. I intend to submit the first patchset to this list to get this driver upstream but I want to go sure that using a workqueue here is ok. See [4] for my hid driver which is located at drivers/hid/hid-wiimote.c. The related patch that introduces the buffered out-queue is [5]. If there is any other way to send complex HID output reports to a device other than the hid_output_raw_report() function, I could rewrite this, but the wiimote protocol really requires this functionality and I couldn't find any other HID driver that has similar requirements. Any comments are appreciated. Kind regards David [1] General Device information: http://en.wikipedia.org/wiki/Wiimote [2] Reverse-Engineered Protocol: http://wiibrew.org/wiki/Wiimote [3] Bluetooth-Details: https://github.com/dvdhrm/xwiimote/blob/master/doc/PROTOCOL [4] My tree (based on jikos/master): https://github.com/dvdhrm/xwiimote_kernel [5] Workqueue patch: https://github.com/dvdhrm/xwiimote_kernel/commit/e8ac07bb2bff7e470a959d44db051d23dc5b0a60 [6] My userspace tools: https://github.com/dvdhrm/xwiimote -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
