gpio: mmio: Make pin2mask() a private business

The vtable call pin2mask() was introducing a vtable function call
in every gpiochip callback for a generic MMIO GPIO chip. This was
not exactly efficient. (Maybe link-time optimization could get rid of
it, I don't know.)

After removing all external calls into this API we can make it a
boolean flag in the struct gpio_chip call and sink the function into
the gpio-mmio driver yielding encapsulation and potential speedups.

Cc: Anton Vorontsov <anton@enomsg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/gpio-mmio.c b/drivers/gpio/gpio-mmio.c
index f7da40e46c55c1f2103a7d7c2ff35da3ab82bbb4..63bb48878de189b4b53397cd378ad0426bbcaaa2 100644 (file)
--- a/drivers/gpio/gpio-mmio.c
+++ b/drivers/gpio/gpio-mmio.c
@@ -126,20 +126,16 @@ static unsigned long bgpio_read32be(void __iomem *reg)
        return ioread32be(reg);
 }
 
-static unsigned long bgpio_pin2mask(struct gpio_chip *gc, unsigned int pin)
+static unsigned long bgpio_line2mask(struct gpio_chip *gc, unsigned int line)
 {
-       return BIT(pin);
-}
-
-static unsigned long bgpio_pin2mask_be(struct gpio_chip *gc,
-                                      unsigned int pin)
-{
-       return BIT(gc->bgpio_bits - 1 - pin);
+       if (gc->be_bits)
+               return BIT(gc->bgpio_bits - 1 - line);
+       return BIT(line);
 }
 
 static int bgpio_get_set(struct gpio_chip *gc, unsigned int gpio)
 {
-       unsigned long pinmask = gc->pin2mask(gc, gpio);
+       unsigned long pinmask = bgpio_line2mask(gc, gpio);
 
        if (gc->bgpio_dir & pinmask)
                return !!(gc->read_reg(gc->reg_set) & pinmask);
@@ -149,7 +145,7 @@ static int bgpio_get_set(struct gpio_chip *gc, unsigned int gpio)
 
 static int bgpio_get(struct gpio_chip *gc, unsigned int gpio)
 {
-       return !!(gc->read_reg(gc->reg_dat) & gc->pin2mask(gc, gpio));
+       return !!(gc->read_reg(gc->reg_dat) & bgpio_line2mask(gc, gpio));
 }
 
 static void bgpio_set_none(struct gpio_chip *gc, unsigned int gpio, int val)
@@ -158,7 +154,7 @@ static void bgpio_set_none(struct gpio_chip *gc, unsigned int gpio, int val)
 
 static void bgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
 {
-       unsigned long mask = gc->pin2mask(gc, gpio);
+       unsigned long mask = bgpio_line2mask(gc, gpio);
        unsigned long flags;
 
        spin_lock_irqsave(&gc->bgpio_lock, flags);
@@ -176,7 +172,7 @@ static void bgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
 static void bgpio_set_with_clear(struct gpio_chip *gc, unsigned int gpio,
                                 int val)
 {
-       unsigned long mask = gc->pin2mask(gc, gpio);
+       unsigned long mask = bgpio_line2mask(gc, gpio);
 
        if (val)
                gc->write_reg(gc->reg_set, mask);
@@ -186,7 +182,7 @@ static void bgpio_set_with_clear(struct gpio_chip *gc, unsigned int gpio,
 
 static void bgpio_set_set(struct gpio_chip *gc, unsigned int gpio, int val)
 {
-       unsigned long mask = gc->pin2mask(gc, gpio);
+       unsigned long mask = bgpio_line2mask(gc, gpio);
        unsigned long flags;
 
        spin_lock_irqsave(&gc->bgpio_lock, flags);
@@ -216,9 +212,9 @@ static void bgpio_multiple_get_masks(struct gpio_chip *gc,
                        break;
                if (__test_and_clear_bit(i, mask)) {
                        if (test_bit(i, bits))
-                               *set_mask |= gc->pin2mask(gc, i);
+                               *set_mask |= bgpio_line2mask(gc, i);
                        else
-                               *clear_mask |= gc->pin2mask(gc, i);
+                               *clear_mask |= bgpio_line2mask(gc, i);
                }
        }
 }
@@ -294,7 +290,7 @@ static int bgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
 
        spin_lock_irqsave(&gc->bgpio_lock, flags);
 
-       gc->bgpio_dir &= ~gc->pin2mask(gc, gpio);
+       gc->bgpio_dir &= ~bgpio_line2mask(gc, gpio);
        gc->write_reg(gc->reg_dir, gc->bgpio_dir);
 
        spin_unlock_irqrestore(&gc->bgpio_lock, flags);
@@ -305,7 +301,7 @@ static int bgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
 static int bgpio_get_dir(struct gpio_chip *gc, unsigned int gpio)
 {
        /* Return 0 if output, 1 of input */
-       return !(gc->read_reg(gc->reg_dir) & gc->pin2mask(gc, gpio));
+       return !(gc->read_reg(gc->reg_dir) & bgpio_line2mask(gc, gpio));
 }
 
 static int bgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
@@ -316,7 +312,7 @@ static int bgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
 
        spin_lock_irqsave(&gc->bgpio_lock, flags);
 
-       gc->bgpio_dir |= gc->pin2mask(gc, gpio);
+       gc->bgpio_dir |= bgpio_line2mask(gc, gpio);
        gc->write_reg(gc->reg_dir, gc->bgpio_dir);
 
        spin_unlock_irqrestore(&gc->bgpio_lock, flags);
@@ -330,7 +326,7 @@ static int bgpio_dir_in_inv(struct gpio_chip *gc, unsigned int gpio)
 
        spin_lock_irqsave(&gc->bgpio_lock, flags);
 
-       gc->bgpio_dir |= gc->pin2mask(gc, gpio);
+       gc->bgpio_dir |= bgpio_line2mask(gc, gpio);
        gc->write_reg(gc->reg_dir, gc->bgpio_dir);
 
        spin_unlock_irqrestore(&gc->bgpio_lock, flags);
@@ -346,7 +342,7 @@ static int bgpio_dir_out_inv(struct gpio_chip *gc, unsigned int gpio, int val)
 
        spin_lock_irqsave(&gc->bgpio_lock, flags);
 
-       gc->bgpio_dir &= ~gc->pin2mask(gc, gpio);
+       gc->bgpio_dir &= ~bgpio_line2mask(gc, gpio);
        gc->write_reg(gc->reg_dir, gc->bgpio_dir);
 
        spin_unlock_irqrestore(&gc->bgpio_lock, flags);
@@ -357,12 +353,11 @@ static int bgpio_dir_out_inv(struct gpio_chip *gc, unsigned int gpio, int val)
 static int bgpio_get_dir_inv(struct gpio_chip *gc, unsigned int gpio)
 {
        /* Return 0 if output, 1 if input */
-       return !!(gc->read_reg(gc->reg_dir) & gc->pin2mask(gc, gpio));
+       return !!(gc->read_reg(gc->reg_dir) & bgpio_line2mask(gc, gpio));
 }
 
 static int bgpio_setup_accessors(struct device *dev,
                                 struct gpio_chip *gc,
-                                bool bit_be,
                                 bool byte_be)
 {
 
@@ -406,8 +401,6 @@ static int bgpio_setup_accessors(struct device *dev,
                return -EINVAL;
        }
 
-       gc->pin2mask = bit_be ? bgpio_pin2mask_be : bgpio_pin2mask;
-
        return 0;
 }
 
@@ -531,8 +524,8 @@ int bgpio_init(struct gpio_chip *gc, struct device *dev,
        if (ret)
                return ret;
 
-       ret = bgpio_setup_accessors(dev, gc, flags & BGPIOF_BIG_ENDIAN,
-                                   flags & BGPIOF_BIG_ENDIAN_BYTE_ORDER);
+       gc->be_bits = !!(flags & BGPIOF_BIG_ENDIAN);
+       ret = bgpio_setup_accessors(dev, gc, flags & BGPIOF_BIG_ENDIAN_BYTE_ORDER);
        if (ret)
                return ret;
 

diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index bda95a9b7b8c0a4092d842cac3a57a2164882722..ed04fa2a00a89d3fb3c176afaa58ea13e6c58ecb 100644 (file)
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -67,9 +67,9 @@ struct module;
  *     registers.
  * @read_reg: reader function for generic GPIO
  * @write_reg: writer function for generic GPIO
- * @pin2mask: some generic GPIO controllers work with the big-endian bits
- *     notation, e.g. in a 8-bits register, GPIO7 is the least significant
- *     bit. This callback assigns the right bit mask.
+ * @be_bits: if the generic GPIO has big endian bit order (bit 31 is representing
+ *     line 0, bit 30 is line 1 ... bit 0 is line 31) this is set to true by the
+ *     generic GPIO core. It is for internal housekeeping only.
  * @reg_dat: data (in) register for generic GPIO
  * @reg_set: output set register (out=high) for generic GPIO
  * @reg_clr: output clear register (out=low) for generic GPIO
@@ -151,7 +151,7 @@ struct gpio_chip {
 #if IS_ENABLED(CONFIG_GPIO_GENERIC)
        unsigned long (*read_reg)(void __iomem *reg);
        void (*write_reg)(void __iomem *reg, unsigned long data);
-       unsigned long (*pin2mask)(struct gpio_chip *gc, unsigned int pin);
+       bool be_bits;
        void __iomem *reg_dat;
        void __iomem *reg_set;
        void __iomem *reg_clr;