On Mon, Oct 13, 2014 at 11:23:59AM -0700, David Cohen wrote: > Even if a gpio pin is set to output, we still need to set INPUT_EN bit here you say you're setting that bit. > to be able to read its value. Without this change, we'll always read low > level state. > > Cc: <stable@xxxxxxxxxxxxxxx> # v3.14+ > Signed-off-by: David Cohen <david.a.cohen@xxxxxxxxxxxxxxx> > --- > > Hi, > > I'm resending same v1 patch but now copying linux stable and linux gpio. > This patch is meant for all linux stable trees >= v3.14. > > Br, David > --- > > drivers/pinctrl/pinctrl-baytrail.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pinctrl/pinctrl-baytrail.c b/drivers/pinctrl/pinctrl-baytrail.c > index e12e5b07f6d7..c23d8ded936d 100644 > --- a/drivers/pinctrl/pinctrl-baytrail.c > +++ b/drivers/pinctrl/pinctrl-baytrail.c > @@ -318,7 +318,7 @@ static int byt_gpio_direction_output(struct gpio_chip *chip, > "Potential Error: Setting GPIO with direct_irq_en to output"); > > reg_val = readl(reg) | BYT_DIR_MASK; > - reg_val &= ~BYT_OUTPUT_EN; > + reg_val &= ~(BYT_OUTPUT_EN | BYT_INPUT_EN); but code is clearing it. Also, you're not patching byt_gpio_get(), so you can't be 'reading its value' either. Quite frankly, this looks very fishy to me. Comments on BYT_OUTPUT_EN and BYT_INPUT_EN states that those bits are active low, meaning that clearing them enables that particular feature. How can you enable a pin to be both OUTPUT and INPUT ? Look like what you really want is: diff --git a/drivers/pinctrl/pinctrl-baytrail.c b/drivers/pinctrl/pinctrl-baytrail.c index e12e5b0..69f882d 100644 --- a/drivers/pinctrl/pinctrl-baytrail.c +++ b/drivers/pinctrl/pinctrl-baytrail.c @@ -290,6 +290,7 @@ static int byt_gpio_direction_input(struct gpio_chip *chip, unsigned offset) value = readl(reg) | BYT_DIR_MASK; value &= ~BYT_INPUT_EN; /* active low */ + value |= BYT_OUTPUT_EN; /* disable output */ writel(value, reg); spin_unlock_irqrestore(&vg->lock, flags); @@ -319,6 +320,7 @@ static int byt_gpio_direction_output(struct gpio_chip *chip, reg_val = readl(reg) | BYT_DIR_MASK; reg_val &= ~BYT_OUTPUT_EN; + value |= BYT_INPUT_EN; /* disable input */ if (value) writel(reg_val | BYT_LEVEL, reg); completely untested however. Care to further explain why clearing both bits - thus enabling both INPUT and OUTPUT - is correct ? -- balbi
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