ar71xx_gpio.c touches SPI_CS1 and 2?
Warner Losh
imp at bsdimp.com
Sun Dec 4 17:21:53 UTC 2011
On Dec 4, 2011, at 5:14 AM, Stefan Bethke wrote:
> I was looking into why I can't manipulate the USB led on my TL-WR1043ND, and came across the SPI chip selects, which share GPIO 0 and 1, respectively. The USB led is hooked up to GPIO 1.
>
> sys/mips/atheros/ar71xx_gpio.c:ar71xx_gpio_attach(device_t dev) enables both chip selects, and detach disables them again.
>
> Two points:
>
> - how can we express different uses for those two pins on a per-board config?
>
> - disabling the function is not correct for the gpio driver, I would think. If you load and unload it as a module, I expect losing access to the flash.
When I was looking into this question for the Atmel chips, I was torn. On the one hand, it would be nice if there was a pin mux device. On the other hand, it didn't map well into the device model. I finally settled on having per-board functions that setup the pins. This is also the model followed by linux. Either the boot loader or the board-dependent code would do the setup.
Warner
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