diff options
| -rw-r--r-- | drivers/mfd/ucb1x00-core.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/drivers/mfd/ucb1x00-core.c b/drivers/mfd/ucb1x00-core.c index 8ebda97981e1..febc90cdef7e 100644 --- a/drivers/mfd/ucb1x00-core.c +++ b/drivers/mfd/ucb1x00-core.c @@ -148,16 +148,22 @@ static int ucb1x00_gpio_direction_output(struct gpio_chip *chip, unsigned offset { struct ucb1x00 *ucb = container_of(chip, struct ucb1x00, gpio); unsigned long flags; + unsigned old, mask = 1 << offset; spin_lock_irqsave(&ucb->io_lock, flags); - ucb->io_dir |= (1 << offset); - ucb1x00_reg_write(ucb, UCB_IO_DIR, ucb->io_dir); - + old = ucb->io_out; if (value) - ucb->io_out |= 1 << offset; + ucb->io_out |= mask; else - ucb->io_out &= ~(1 << offset); - ucb1x00_reg_write(ucb, UCB_IO_DATA, ucb->io_out); + ucb->io_out &= ~mask; + + if (old != ucb->io_out) + ucb1x00_reg_write(ucb, UCB_IO_DATA, ucb->io_out); + + if (!(ucb->io_dir & mask)) { + ucb->io_dir |= mask; + ucb1x00_reg_write(ucb, UCB_IO_DIR, ucb->io_dir); + } spin_unlock_irqrestore(&ucb->io_lock, flags); return 0; |