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path: root/drivers/gpio/gpio-mmio.c
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Diffstat (limited to 'drivers/gpio/gpio-mmio.c')
-rw-r--r--drivers/gpio/gpio-mmio.c108
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,