gpio-ch341.c: write_outputs, use new command

[mr-nice]

Change write_outputs to use the 0xA1 pin IO interface from https://github.com/rogerjames99/spi-ch341-usb/blob/master/spi-ch341-usb.c

Keep the current interface of the old command and don't use new pins.

Reverse engineered from @Icenowy and @geeksville

Also used at the manufacturers driver code example https://github.com/zoobab/ch341-parport/blob/master/CH341PAR_LINUX/demo/ch34x_lib.c

[mr-nice]

Hi,
I did the first step and changed the I/O command to the new interface without changing anything on the other interfaces. I tested the result with gpioget with pins driven to low (connect gnd to the pin). And tested the outputs D0-D5 with gpioset and a logic analyzer.
I was unable to test the SPI interface because this would need the INI# pin. I was also unable to test I2C because there is no driver for my I2C device. I have an I2C device and I can connect it but I missed some parts to get i2cdetect to work with both write_output implementations. I need to further investigate that, because I never used that on a non embedded machine. I can test the things you want me to test, if you provide information on how to test them.

I left out all the enhancements which this interface gives us to another PR to solve #5

The library code mentioned that it might be possible to use more pins as outputs but I leave that out for later.

Greets,
mr-nice

[frank-zago]

Thanks. That looks good. I've tested it as well. Fix the typo and I'll merge.

[frank-zago]

rebased and merged.