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>

1 files changed, 76 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-generic.c b/drivers/gpio/gpio-generic.c
index 16f6115e5bdb..b92a690f5765 100644
--- 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;