Messages in this thread | | | Subject | Re: [PATCH V2 7/7] USB: serial: f81232: Add gpiolib to GPIO device | From | "Ji-Ze Hong (Peter Hong)" <> | Date | Thu, 9 Jan 2020 10:43:48 +0800 |
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Hi Johan,
Johan Hovold 於 2020/1/8 下午 10:46 寫道: > On Wed, Oct 30, 2019 at 10:00:12AM +0800, Ji-Ze Hong (Peter Hong) wrote:
>> We had 2 type about GPIO pins, MODEx_y & GPIOxx. All MODEx_y & GPIOxx >> are GPIOs and can be controlled by GPIO device, but they had some >> difference about usage. >> MODEx_y: >> 1. 3 pins(x: 0/1/2) can be access by UART port y. >> 2. Used to control UART's transceiver normally, but it >> also can be configure as GPIO when UART disabled by >> H/W (DTR strap to GND). >> GPIOxx: >> 1. Access only by GPIO device. >> >> The series patch only support RS233 mode for all serial port, So we'll >> direct set all MODEx_y to (0/0/1) for our demo board for default. If >> user really want to use the pin, we had provide the gpiolib with GPIO >> device, but we'll recommend user to use GPIOxy first. > > Do you mean that you'd need to register a separate gpio chip per port in > order to expose an interface for changing the MODEx_y pins for an > enabled UART? Or can you do that through the "global" gpio device?
No, I still implement the gpiolib in GPIO Device. Sorry for bad describe.
>> Is any suggest about this ? Could I maintain this for this series patch? > > I understood from your other mail that the gpio device would not be able > to control the pins of an enabled port. In either case, I think you need > to refuse a request for a pin that's already in use by the corresponding > port.
OK, I'll change the code as previous mail as following:
I can read the UART enable state from GPIO Device, so I can do when the GPIO is associated with UART enabled, change it as output only otherwise can be set to input/output.
> Also is there a way to determine the number of available pins by > detecting the chip/package type? I'm assuming not all 36 pins are always > accessible?
Yes, we had register to get package type, I'll add UART enable & package type to determinate final GPIO pin out.
-- With Best Regards, Peter Hong
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