diff options
Diffstat (limited to 'drivers/gpio/gpio-mmio.c')
| -rw-r--r-- | drivers/gpio/gpio-mmio.c | 108 |
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, |