gpio: aspeed: Add open-source and open-drain support

As per the datasheet, manage the IO and value states to implement
open-source/open-drain, but do this by falling back to gpiolib's
emulation.

This commit simply makes the behaviour explicit for clarity, rather than
relying on the implicit return of -ENOTSUPP to trigger the emulation.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-aspeed.c b/drivers/gpio/gpio-aspeed.c
index 3327a48df862..ccea609676ee 100644
--- a/drivers/gpio/gpio-aspeed.c
+++ b/drivers/gpio/gpio-aspeed.c
@@ -761,6 +761,10 @@ static int aspeed_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
                         param == PIN_CONFIG_BIAS_PULL_DOWN ||
                         param == PIN_CONFIG_DRIVE_STRENGTH)
                 return pinctrl_gpio_set_config(offset, config);
+        else if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN ||
+                        param == PIN_CONFIG_DRIVE_OPEN_SOURCE)
+                /* Return -ENOTSUPP to trigger emulation, as per datasheet */
+                return -ENOTSUPP;
 
         return -ENOTSUPP;
 }