1 files changed, 63 insertions, 45 deletions

diff --git a/drivers/gpio/gpio-mmio.c b/drivers/gpio/gpio-mmio.c
index 7b14d6280e44..935292a30c99 100644
--- a/drivers/gpio/gpio-mmio.c
+++ b/drivers/gpio/gpio-mmio.c
@@ -136,8 +136,20 @@ static unsigned long bgpio_line2mask(struct gpio_chip *gc, unsigned int line)
 static int bgpio_get_set(struct gpio_chip *gc, unsigned int gpio)
 {
         unsigned long pinmask = bgpio_line2mask(gc, gpio);
+        bool dir = !!(gc->bgpio_dir & pinmask);
 
-        if (gc->bgpio_dir & pinmask)
+        /*
+         * If the direction is OUT we read the value from the SET
+         * register, and if the direction is IN we read the value
+         * from the DAT register.
+         *
+         * If the direction bits are inverted, naturally this gets
+         * inverted too.
+         */
+        if (gc->bgpio_dir_inverted)
+                dir = !dir;
+
+        if (dir)
                 return !!(gc->read_reg(gc->reg_set) & pinmask);
         else
                 return !!(gc->read_reg(gc->reg_dat) & pinmask);
@@ -157,8 +169,13 @@ static int bgpio_get_set_multiple(struct gpio_chip *gc, unsigned long *mask,
         *bits &= ~*mask;
 
         /* Exploit the fact that we know which directions are set */
-        set_mask = *mask & gc->bgpio_dir;
-        get_mask = *mask & ~gc->bgpio_dir;
+        if (gc->bgpio_dir_inverted) {
+                set_mask = *mask & ~gc->bgpio_dir;
+                get_mask = *mask & gc->bgpio_dir;
+        } else {
+                set_mask = *mask & gc->bgpio_dir;
+                get_mask = *mask & ~gc->bgpio_dir;
+        }
 
         if (set_mask)
                 *bits |= gc->read_reg(gc->reg_set) & set_mask;
@@ -359,7 +376,10 @@ static int bgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
 
         spin_lock_irqsave(&gc->bgpio_lock, flags);
 
-        gc->bgpio_dir &= ~bgpio_line2mask(gc, gpio);
+        if (gc->bgpio_dir_inverted)
+                gc->bgpio_dir |= bgpio_line2mask(gc, gpio);
+        else
+                gc->bgpio_dir &= ~bgpio_line2mask(gc, gpio);
         gc->write_reg(gc->reg_dir, gc->bgpio_dir);
 
         spin_unlock_irqrestore(&gc->bgpio_lock, flags);
@@ -370,7 +390,10 @@ 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) & bgpio_line2mask(gc, gpio));
+        if (gc->bgpio_dir_inverted)
+                return !!(gc->read_reg(gc->reg_dir) & bgpio_line2mask(gc, gpio));
+        else
+                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)
@@ -381,37 +404,10 @@ static int bgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
 
         spin_lock_irqsave(&gc->bgpio_lock, flags);
 
-        gc->bgpio_dir |= bgpio_line2mask(gc, gpio);
-        gc->write_reg(gc->reg_dir, gc->bgpio_dir);
-
-        spin_unlock_irqrestore(&gc->bgpio_lock, flags);
-
-        return 0;
-}
-
-static int bgpio_dir_in_inv(struct gpio_chip *gc, unsigned int gpio)
-{
-        unsigned long flags;
-
-        spin_lock_irqsave(&gc->bgpio_lock, flags);
-
-        gc->bgpio_dir |= bgpio_line2mask(gc, gpio);
-        gc->write_reg(gc->reg_dir, gc->bgpio_dir);
-
-        spin_unlock_irqrestore(&gc->bgpio_lock, flags);
-
-        return 0;
-}
-
-static int bgpio_dir_out_inv(struct gpio_chip *gc, unsigned int gpio, int val)
-{
-        unsigned long flags;
-
-        gc->set(gc, gpio, val);
-
-        spin_lock_irqsave(&gc->bgpio_lock, flags);
-
-        gc->bgpio_dir &= ~bgpio_line2mask(gc, gpio);
+        if (gc->bgpio_dir_inverted)
+                gc->bgpio_dir &= ~bgpio_line2mask(gc, gpio);
+        else
+                gc->bgpio_dir |= bgpio_line2mask(gc, gpio);
         gc->write_reg(gc->reg_dir, gc->bgpio_dir);
 
         spin_unlock_irqrestore(&gc->bgpio_lock, flags);
@@ -419,12 +415,6 @@ static int bgpio_dir_out_inv(struct gpio_chip *gc, unsigned int gpio, int val)
         return 0;
 }
 
-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) & bgpio_line2mask(gc, gpio));
-}
-
 static int bgpio_setup_accessors(struct device *dev,
                                  struct gpio_chip *gc,
                                  bool byte_be)
@@ -560,9 +550,10 @@ static int bgpio_setup_direction(struct gpio_chip *gc,
                 gc->get_direction = bgpio_get_dir;
         } else if (dirin) {
                 gc->reg_dir = dirin;
-                gc->direction_output = bgpio_dir_out_inv;
-                gc->direction_input = bgpio_dir_in_inv;
-                gc->get_direction = bgpio_get_dir_inv;
+                gc->direction_output = bgpio_dir_out;
+                gc->direction_input = bgpio_dir_in;
+                gc->get_direction = bgpio_get_dir;
+                gc->bgpio_dir_inverted = true;
         } else {
                 if (flags & BGPIOF_NO_OUTPUT)
                         gc->direction_output = bgpio_dir_out_err;
@@ -582,6 +573,33 @@ static int bgpio_request(struct gpio_chip *chip, unsigned gpio_pin)
         return -EINVAL;
 }
 
+/**
+ * bgpio_init() - Initialize generic GPIO accessor functions
+ * @gc: the GPIO chip to set up
+ * @dev: the parent device of the new GPIO chip (compulsory)
+ * @sz: the size (width) of the MMIO registers in bytes, typically 1, 2 or 4
+ * @dat: MMIO address for the register to READ the value of the GPIO lines, it
+ *      is expected that a 1 in the corresponding bit in this register means the
+ *      line is asserted
+ * @set: MMIO address for the register to SET the value of the GPIO lines, it is
+ *      expected that we write the line with 1 in this register to drive the GPIO line
+ *      high.
+ * @clr: MMIO address for the register to CLEAR the value of the GPIO lines, it is
+ *      expected that we write the line with 1 in this register to drive the GPIO line
+ *      low. It is allowed to leave this address as NULL, in that case the SET register
+ *      will be assumed to also clear the GPIO lines, by actively writing the line
+ *      with 0.
+ * @dirout: MMIO address for the register to set the line as OUTPUT. It is assumed
+ *      that setting a line to 1 in this register will turn that line into an
+ *      output line. Conversely, setting the line to 0 will turn that line into
+ *      an input. Either this or @dirin can be defined, but never both.
+ * @dirin: MMIO address for the register to set this line as INPUT. It is assumed
+ *      that setting a line to 1 in this register will turn that line into an
+ *      input line. Conversely, setting the line to 0 will turn that line into
+ *      an output. Either this or @dirout can be defined, but never both.
+ * @flags: Different flags that will affect the behaviour of the device, such as
+ *      endianness etc.
+ */
 int bgpio_init(struct gpio_chip *gc, struct device *dev,
                unsigned long sz, void __iomem *dat, void __iomem *set,
                void __iomem *clr, void __iomem *dirout, void __iomem *dirin,