gpio-generic: add bgpio_set_multiple functions

Add set_multiple functions to the generic driver for memory-mapped GPIO
controllers to improve performance when setting multiple outputs
simultaneously.

Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/gpio-generic.c b/drivers/gpio/gpio-generic.c
index 16f6115e5bdb5fd8ae2ff32b706f008e2a041d8a..b92a690f5765c37457147b83ecac3cb810b5641c 100644 (file)
--- a/drivers/gpio/gpio-generic.c
+++ b/drivers/gpio/gpio-generic.c
@@ -190,6 +190,79 @@ static void bgpio_set_set(struct gpio_chip *gc, unsigned int gpio, int val)
        spin_unlock_irqrestore(&bgc->lock, flags);
 }
 
+static void bgpio_multiple_get_masks(struct bgpio_chip *bgc,
+                                    unsigned long *mask, unsigned long *bits,
+                                    unsigned long *set_mask,
+                                    unsigned long *clear_mask)
+{
+       int i;
+
+       *set_mask = 0;
+       *clear_mask = 0;
+
+       for (i = 0; i < bgc->bits; i++) {
+               if (*mask == 0)
+                       break;
+               if (__test_and_clear_bit(i, mask)) {
+                       if (test_bit(i, bits))
+                               *set_mask |= bgc->pin2mask(bgc, i);
+                       else
+                               *clear_mask |= bgc->pin2mask(bgc, i);
+               }
+       }
+}
+
+static void bgpio_set_multiple_single_reg(struct bgpio_chip *bgc,
+                                         unsigned long *mask,
+                                         unsigned long *bits,
+                                         void __iomem *reg)
+{
+       unsigned long flags;
+       unsigned long set_mask, clear_mask;
+
+       spin_lock_irqsave(&bgc->lock, flags);
+
+       bgpio_multiple_get_masks(bgc, mask, bits, &set_mask, &clear_mask);
+
+       bgc->data |= set_mask;
+       bgc->data &= ~clear_mask;
+
+       bgc->write_reg(reg, bgc->data);
+
+       spin_unlock_irqrestore(&bgc->lock, flags);
+}
+
+static void bgpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
+                              unsigned long *bits)
+{
+       struct bgpio_chip *bgc = to_bgpio_chip(gc);
+
+       bgpio_set_multiple_single_reg(bgc, mask, bits, bgc->reg_dat);
+}
+
+static void bgpio_set_multiple_set(struct gpio_chip *gc, unsigned long *mask,
+                                  unsigned long *bits)
+{
+       struct bgpio_chip *bgc = to_bgpio_chip(gc);
+
+       bgpio_set_multiple_single_reg(bgc, mask, bits, bgc->reg_set);
+}
+
+static void bgpio_set_multiple_with_clear(struct gpio_chip *gc,
+                                         unsigned long *mask,
+                                         unsigned long *bits)
+{
+       struct bgpio_chip *bgc = to_bgpio_chip(gc);
+       unsigned long set_mask, clear_mask;
+
+       bgpio_multiple_get_masks(bgc, mask, bits, &set_mask, &clear_mask);
+
+       if (set_mask)
+               bgc->write_reg(bgc->reg_set, set_mask);
+       if (clear_mask)
+               bgc->write_reg(bgc->reg_clr, clear_mask);
+}
+
 static int bgpio_simple_dir_in(struct gpio_chip *gc, unsigned int gpio)
 {
        return 0;
@@ -354,11 +427,14 @@ static int bgpio_setup_io(struct bgpio_chip *bgc,
                bgc->reg_set = set;
                bgc->reg_clr = clr;
                bgc->gc.set = bgpio_set_with_clear;
+               bgc->gc.set_multiple = bgpio_set_multiple_with_clear;
        } else if (set && !clr) {
                bgc->reg_set = set;
                bgc->gc.set = bgpio_set_set;
+               bgc->gc.set_multiple = bgpio_set_multiple_set;
        } else {
                bgc->gc.set = bgpio_set;
+               bgc->gc.set_multiple = bgpio_set_multiple;
        }
 
        bgc->gc.get = bgpio_get;