On Tue, Apr 22, 2014 at 12:24 PM, Javier Martinez Canillas
[off-list ref] wrote:

Hello Yegor,

On Tue, Apr 22, 2014 at 11:23 AM,  [off-list ref] wrote:

quoted

From: Yegor Yefremov <redacted>

This patch implements gpio_chip's get_direction() routine, that
lets other drivers get particular GPIOs direction using
struct gpio_desc.

Signed-off-by: Yegor Yefremov <redacted>
---
 drivers/gpio/gpio-omap.c |   28 ++++++++++++++++++++++++++++
 1 files changed, 28 insertions(+), 0 deletions(-)

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index 19b886c..b55bf7b 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c

@@ -102,6 +102,20 @@ static int omap_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
        return irq_find_mapping(bank->domain, offset);
 }

+static int _get_gpio_direction(struct gpio_bank *bank, int gpio)
+{
+       void __iomem *reg = bank->base;
+       u32 l;
+       u32 mask = 1 << gpio;
+
+       reg += bank->regs->direction;
+       l = readl_relaxed(reg);
+       if (l & mask)
+               return 1;
+
+       return 0;
+}
+

You can avoid the if condition here by using return !!(l & mask) but
the above code is more clear indeed so is up to you.

Hm, nice trick. I've reworked the calculation in v2.

Yegor