[PATCH] gpio-aspeed: Write value on switch to output

[Andrew Jeffery]

[0] notes that the Barreleye beep LED turned off during boot despite
configuring the default-state DT property to "on". The documentation for the
direction_output() callback in struct gpio_chip doesn't make any mention of
setting values[1] but the function prototype takes a value as a formal
parameter. Additionally, other drivers' callback implementations (e.g. the
gemini GPIO driver) write out the provided value.

Make the Aspeed GPIO driver implementation consistent with the expected
behaviour.

[0] https://github.com/openbmc/linux/issues/98
[1] "@direction_output: configures signal "offset" as output, or returns error"

Signed-off-by: Andrew Jeffery <andrew at aj.id.au>
---
 drivers/gpio/gpio-aspeed.c | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/drivers/gpio/gpio-aspeed.c b/drivers/gpio/gpio-aspeed.c
index 2ecaa2b12759..7817b98fe8cd 100644
--- a/drivers/gpio/gpio-aspeed.c
+++ b/drivers/gpio/gpio-aspeed.c
@@ -120,23 +120,29 @@ static int aspeed_gpio_get(struct gpio_chip *gc, unsigned int offset)
 			& GPIO_BIT(offset));
 }
 
-static void aspeed_gpio_set(struct gpio_chip *gc, unsigned int offset,
-			    int val)
+static void __aspeed_gpio_set(void __iomem *addr, unsigned int offset, int val)
 {
-	struct aspeed_gpio *gpio = to_aspeed_gpio(gc);
-	const struct aspeed_gpio_bank *bank = to_bank(offset);
-	unsigned long flags;
 	u32 reg;
 
-	spin_lock_irqsave(&gpio->lock, flags);
-
-	reg = ioread32(bank_val_reg(gpio, bank, GPIO_DATA));
+	reg = ioread32(addr);
 	if (val)
 		reg |= GPIO_BIT(offset);
 	else
 		reg &= ~GPIO_BIT(offset);
 
-	iowrite32(reg, bank_val_reg(gpio, bank, GPIO_DATA));
+	iowrite32(reg, addr);
+}
+
+static void aspeed_gpio_set(struct gpio_chip *gc, unsigned int offset,
+			    int val)
+{
+	struct aspeed_gpio *gpio = to_aspeed_gpio(gc);
+	const struct aspeed_gpio_bank *bank = to_bank(offset);
+	unsigned long flags;
+
+	spin_lock_irqsave(&gpio->lock, flags);
+
+	__aspeed_gpio_set(bank_val_reg(gpio, bank, GPIO_DATA), offset, val);
 
 	spin_unlock_irqrestore(&gpio->lock, flags);
 }
@@ -163,13 +169,16 @@ static int aspeed_gpio_dir_out(struct gpio_chip *gc,
 {
 	struct aspeed_gpio *gpio = to_aspeed_gpio(gc);
 	const struct aspeed_gpio_bank *bank = to_bank(offset);
+	void __iomem *addr = bank_val_reg(gpio, bank, GPIO_DIR);
 	unsigned long flags;
 	u32 reg;
 
 	spin_lock_irqsave(&gpio->lock, flags);
 
-	reg = ioread32(bank_val_reg(gpio, bank, GPIO_DIR));
-	iowrite32(reg | GPIO_BIT(offset), bank_val_reg(gpio, bank, GPIO_DIR));
+	reg = ioread32(addr);
+	iowrite32(reg | GPIO_BIT(offset), addr);
+
+	__aspeed_gpio_set(addr, offset, val);
 
 	spin_unlock_irqrestore(&gpio->lock, flags);
 
-- 
2.9.2.597.g66765a4