gpio: rcar: Implement gpio_chip.get_multiple()

Add support for getting the state of multiple pins using a minimum of
register reads.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

diff --git a/drivers/gpio/gpio-rcar.c b/drivers/gpio/gpio-rcar.c
index b33d1a2..0b572db 100644 (file)
--- a/drivers/gpio/gpio-rcar.c
+++ b/drivers/gpio/gpio-rcar.c
@@ -310,6 +310,35 @@ static int gpio_rcar_get(struct gpio_chip *chip, unsigned offset)
                return !!(gpio_rcar_read(p, INDT) & bit);
 }
 
+static int gpio_rcar_get_multiple(struct gpio_chip *chip, unsigned long *mask,
+                                 unsigned long *bits)
+{
+       struct gpio_rcar_priv *p = gpiochip_get_data(chip);
+       u32 bankmask, outputs, m, val = 0;
+       unsigned long flags;
+
+       bankmask = mask[0] & GENMASK(chip->ngpio - 1, 0);
+       if (chip->valid_mask)
+               bankmask &= chip->valid_mask[0];
+
+       if (!bankmask)
+               return 0;
+
+       spin_lock_irqsave(&p->lock, flags);
+       outputs = gpio_rcar_read(p, INOUTSEL);
+       m = outputs & bankmask;
+       if (m)
+               val |= gpio_rcar_read(p, OUTDT) & m;
+
+       m = ~outputs & bankmask;
+       if (m)
+               val |= gpio_rcar_read(p, INDT) & m;
+       spin_unlock_irqrestore(&p->lock, flags);
+
+       bits[0] = val;
+       return 0;
+}
+
 static void gpio_rcar_set(struct gpio_chip *chip, unsigned offset, int value)
 {
        struct gpio_rcar_priv *p = gpiochip_get_data(chip);
@@ -478,6 +507,7 @@ static int gpio_rcar_probe(struct platform_device *pdev)
        gpio_chip->get_direction = gpio_rcar_get_direction;
        gpio_chip->direction_input = gpio_rcar_direction_input;
        gpio_chip->get = gpio_rcar_get;
+       gpio_chip->get_multiple = gpio_rcar_get_multiple;
        gpio_chip->direction_output = gpio_rcar_direction_output;
        gpio_chip->set = gpio_rcar_set;
        gpio_chip->set_multiple = gpio_rcar_set_multiple;