sc16is7xx: always write state when configuring GPIO as an output

The regmap_update first reads the IOState register and then triggers
a write if needed. However, GPIOS might be configured as an input so
 the read to IOState on this GPIO is the current state which might
be random.

Signed-off-by: Francois Berder <Francois.Berder@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Francois Berder 2016-10-25 13:24:13 +01:00 committed by Greg Kroah-Hartman
parent c03e1b8703
commit 03842c1739

View File

@ -1130,9 +1130,13 @@ static int sc16is7xx_gpio_direction_output(struct gpio_chip *chip,
{
struct sc16is7xx_port *s = gpiochip_get_data(chip);
struct uart_port *port = &s->p[0].port;
u8 state = sc16is7xx_port_read(port, SC16IS7XX_IOSTATE_REG);
sc16is7xx_port_update(port, SC16IS7XX_IOSTATE_REG, BIT(offset),
val ? BIT(offset) : 0);
if (val)
state |= BIT(offset);
else
state &= ~BIT(offset);
sc16is7xx_port_write(port, SC16IS7XX_IOSTATE_REG, state);
sc16is7xx_port_update(port, SC16IS7XX_IODIR_REG, BIT(offset),
BIT(offset));