On 02/10/2014 08:31 PM, Alexandre Courbot wrote:
On Tue, Feb 11, 2014 at 7:05 AM, David Daney <ddaney.cavm@xxxxxxxxx> wrote:From: David Daney <david.daney@xxxxxxxxxx> When we have a GPIO pin connected to an open-drain network, we want a standard way of specifying this in the device tree. So we choose bit 1 of the flag field to indicate open drain. A typical use case would be something like: enum of_gpio_flags f; . . . reset_gpio = of_get_named_gpio_flags(node, "reset", 0, &f); . . . ret = gpio_request_one(reset_gpio, (f & OF_GPIO_OPEN_DRAIN) ? GPIOF_OPEN_DRAIN : 0, "reset"); . . . gpio_direction_output(reset_gpio, 1); gpio_set_value(reset_gpio, 0); msleep(20); gpio_set_value(reset_gpio, 1);This is also useful for gpiod_get(). However, while you are at it, could you also add a flag for the OF_GPIO_OPEN_SOURCE property? My joy would be complete if you could also take the time to update of_find_gpio() to pass these new flags back to the caller as it already does for OF_GPIO_ACTIVE_LOW. Then you could even switch your use-case to the gpiod interface and not bother with passing these flags by yourself anymore. Just sayin'. ;)
Thanks for the suggestion. I will send a revised patch set for your consideration.
David Daney -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
