mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-25 21:54:06 +08:00
Revert "gpio: set up initial state from .get_direction()"
This reverts commit 72d3200061
.
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: Timur Tabi <timur@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
parent
caa92ee84b
commit
1ca2a92b2a
@ -1217,31 +1217,14 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
|
||||
struct gpio_desc *desc = &gdev->descs[i];
|
||||
|
||||
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.
|
||||
|
||||
/* 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)
|
||||
set_bit(FLAG_IS_OUT, &desc->flags);
|
||||
} else if (!chip->direction_input) {
|
||||
/*
|
||||
* If the chip lacks the .direction_input callback
|
||||
* we logically assume all lines are outputs.
|
||||
*/
|
||||
set_bit(FLAG_IS_OUT, &desc->flags);
|
||||
}
|
||||
desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_PINCTRL
|
||||
|
Loading…
Reference in New Issue
Block a user