Messages in this thread | | | Date | Fri, 13 Aug 2010 17:56:41 -0400 | From | Neil Leeder <> | Subject | Re: [PATCH v2] input: mouse: add qci touchpad driver |
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On 8/12/2010 10:49 PM, Dmitry Torokhov wrote: > On Thu, Aug 12, 2010 at 01:58:18PM -0400, Neil Leeder wrote: > Actually, since this is not a new touchpad but simply a PS/2 interface > it should be implemented as a serio driver, not input device driver. > Dmitri,
Thanks for supplying that serio driver. I just have a couple of questions.
Even though the interface on the wpce775x EC happens to be a PS/2 interface, this is completely hidden by the firmware on that device. To the linux driver it looks like a dedicated i2c connection directly to the touchpad. You can't substitute any other device on that PS/2 interface without rewriting the firmware in the EC - it's not a generic interface. A manufacturer could even move the touchpad from the PS/2 interface to say GPIOs, re-write the firmware and the linux driver couldn't tell the difference. Does that change the rationale for using a serio driver?
If the request to use a serio driver is still valid, then it seems that the workqueue from the interrupt handler sends each byte of data received over i2c in a separate serio_interrupt() call to the touchpad driver. Touchpad data comes in 3-byte packets, so the touchpad driver will have to re-assemble the packet from 3 separate interrupts. Is that the intended use?
> Could you please tell me if the following works for you? Note that it > expects IRQ to be set up properly (edge vs. level trigger) by the > platform code
The i2c_board_info that supplies the irq # from platform code doesn't have a way to set i2c flags, and can't set_irq_type() until after irq_request(). This may require another platform_data struct to pass the trigger level in.
Thanks.
-- Neil -- Sent by an employee of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
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