[PATCH 1/4] gpiolib: add support for bias pull disable

Nuno Sá
2022-07-13T13:13:57Z

This change prepares the gpio core to look at firmware flags and set
'FLAG_BIAS_DISABLE' if necessary. It works in similar way to
'GPIO_PULL_DOWN' and 'GPIO_PULL_UP'.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
---
drivers/gpio/gpiolib.c | 8 ++++++--
include/linux/gpio/machine.h | 1 +
2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 9535f48e18d1..0692ec84d3b0 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -3945,9 +3945,11 @@ int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
if (lflags & GPIO_OPEN_SOURCE)
set_bit(FLAG_OPEN_SOURCE, &desc->flags);

- if ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) {
+ if (((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) ||
+ ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DISABLE)) ||
+ ((lflags & GPIO_PULL_DOWN) && (lflags & GPIO_PULL_DISABLE))) {
gpiod_err(desc,
- "both pull-up and pull-down enabled, invalid configuration\n");
+ "multiple pull-up, pull-down or pull-disable enabled, invalid configuration\n");
return -EINVAL;
}

@@ -3955,6 +3957,8 @@ int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
set_bit(FLAG_PULL_UP, &desc->flags);
else if (lflags & GPIO_PULL_DOWN)
set_bit(FLAG_PULL_DOWN, &desc->flags);
+ else if (lflags & GPIO_PULL_DISABLE)
+ set_bit(FLAG_BIAS_DISABLE, &desc->flags);

ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
if (ret < 0)
diff --git a/include/linux/gpio/machine.h b/include/linux/gpio/machine.h
index 4d55da28e664..0b619eb7ae83 100644
--- a/include/linux/gpio/machine.h
+++ b/include/linux/gpio/machine.h
@@ -14,6 +14,7 @@ enum gpio_lookup_flags {
GPIO_TRANSITORY = (1 << 3),
GPIO_PULL_UP = (1 << 4),
GPIO_PULL_DOWN = (1 << 5),
+ GPIO_PULL_DISABLE = (1 << 6),

GPIO_LOOKUP_FLAGS_DEFAULT = GPIO_ACTIVE_HIGH | GPIO_PERSISTENT,
};
--
2.37.0