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[PATCH v2 4/4] gpio: aspeed: Add open-source and open-drain support

From Andrew Jeffery <andrew@aj.id.au>
Newsgroups linux.kernel
Subject [PATCH v2 4/4] gpio: aspeed: Add open-source and open-drain support
Date 2017-04-07 15:10 +0200
Message-ID <ttBOh-7vK-5@gated-at.bofh.it> (permalink)
References <ttBOh-7vK-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

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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>
---
 drivers/gpio/gpio-aspeed.c | 4 ++++
 1 file changed, 4 insertions(+)

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;
 }
-- 
2.9.3

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Thread

[PATCH v2 0/4] gpio: aspeed: Add debounce support Andrew Jeffery <andrew@aj.id.au> - 2017-04-07 15:10 +0200
  [PATCH v2 4/4] gpio: aspeed: Add open-source and open-drain support Andrew Jeffery <andrew@aj.id.au> - 2017-04-07 15:10 +0200
  [PATCH v2 3/4] gpio: aspeed: Add debounce support Andrew Jeffery <andrew@aj.id.au> - 2017-04-07 15:10 +0200
  [PATCH v2 1/4] gpio: aspeed: dt: Fix description alignment in bindings document Andrew Jeffery <andrew@aj.id.au> - 2017-04-07 15:10 +0200

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