Commit 1ca2a92b authored by Timur Tabi's avatar Timur Tabi Committed by Linus Walleij

Revert "gpio: set up initial state from .get_direction()"

This reverts commit 72d32000.

We cannot blindly query the direction of all GPIOs when the pins are
first registered.  The get_direction callback normally triggers a
read/write to hardware, but we shouldn't be touching the hardware for
an individual GPIO until after it's been properly claimed.
Signed-off-by: default avatarTimur Tabi <timur@codeaurora.org>
Reviewed-by: default avatarStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent caa92ee8
...@@ -1217,31 +1217,14 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data, ...@@ -1217,31 +1217,14 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
struct gpio_desc *desc = &gdev->descs[i]; struct gpio_desc *desc = &gdev->descs[i];
desc->gdev = gdev; desc->gdev = gdev;
/*
* REVISIT: most hardware initializes GPIOs as inputs
* (often with pullups enabled) so power usage is
* minimized. Linux code should set the gpio direction
* first thing; but until it does, and in case
* chip->get_direction is not set, we may expose the
* wrong direction in sysfs.
*/
if (chip->get_direction) {
/*
* If we have .get_direction, set up the initial
* direction flag from the hardware.
*/
int dir = chip->get_direction(chip, i);
if (!dir) /* REVISIT: most hardware initializes GPIOs as inputs (often
set_bit(FLAG_IS_OUT, &desc->flags); * with pullups enabled) so power usage is minimized. Linux
} else if (!chip->direction_input) { * code should set the gpio direction first thing; but until
/* * it does, and in case chip->get_direction is not set, we may
* If the chip lacks the .direction_input callback * expose the wrong direction in sysfs.
* we logically assume all lines are outputs. */
*/ desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
set_bit(FLAG_IS_OUT, &desc->flags);
}
} }
#ifdef CONFIG_PINCTRL #ifdef CONFIG_PINCTRL
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment