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-rw-r--r--drivers/gpio/gpiolib.c61
-rw-r--r--drivers/gpio/gpiolib.h1
-rw-r--r--include/uapi/linux/gpio.h2
3 files changed, 54 insertions, 10 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index b7d7bb8bd20d..996911660306 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -424,6 +424,7 @@ struct linehandle_state {
GPIOHANDLE_REQUEST_ACTIVE_LOW | \
GPIOHANDLE_REQUEST_BIAS_PULL_UP | \
GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | \
+ GPIOHANDLE_REQUEST_BIAS_DISABLE | \
GPIOHANDLE_REQUEST_OPEN_DRAIN | \
GPIOHANDLE_REQUEST_OPEN_SOURCE)
@@ -555,12 +556,21 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip)
(lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
return -EINVAL;
- /* PULL_UP and PULL_DOWN flags only make sense for input mode. */
+ /* Bias flags only allowed for input mode. */
if (!(lflags & GPIOHANDLE_REQUEST_INPUT) &&
- ((lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) ||
+ ((lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) ||
+ (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) ||
(lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN)))
return -EINVAL;
+ /* Only one bias flag can be set. */
+ if (((lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) &&
+ (lflags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN |
+ GPIOHANDLE_REQUEST_BIAS_PULL_UP))) ||
+ ((lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) &&
+ (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP)))
+ return -EINVAL;
+
lh = kzalloc(sizeof(*lh), GFP_KERNEL);
if (!lh)
return -ENOMEM;
@@ -601,6 +611,8 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip)
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
+ if (lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE)
+ set_bit(FLAG_BIAS_DISABLE, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN)
set_bit(FLAG_PULL_DOWN, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP)
@@ -925,6 +937,14 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
(lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
return -EINVAL;
+ /* Only one bias flag can be set. */
+ if (((lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) &&
+ (lflags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN |
+ GPIOHANDLE_REQUEST_BIAS_PULL_UP))) ||
+ ((lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) &&
+ (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP)))
+ return -EINVAL;
+
le = kzalloc(sizeof(*le), GFP_KERNEL);
if (!le)
return -ENOMEM;
@@ -951,6 +971,8 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
+ if (lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE)
+ set_bit(FLAG_BIAS_DISABLE, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN)
set_bit(FLAG_PULL_DOWN, &desc->flags);
if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP)
@@ -1108,6 +1130,8 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
lineinfo.flags |= (GPIOLINE_FLAG_OPEN_SOURCE |
GPIOLINE_FLAG_IS_OUT);
+ if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
+ lineinfo.flags |= GPIOLINE_FLAG_BIAS_DISABLE;
if (test_bit(FLAG_PULL_DOWN, &desc->flags))
lineinfo.flags |= GPIOLINE_FLAG_BIAS_PULL_DOWN;
if (test_bit(FLAG_PULL_UP, &desc->flags))
@@ -2807,6 +2831,7 @@ static bool gpiod_free_commit(struct gpio_desc *desc)
clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
clear_bit(FLAG_PULL_UP, &desc->flags);
clear_bit(FLAG_PULL_DOWN, &desc->flags);
+ clear_bit(FLAG_BIAS_DISABLE, &desc->flags);
clear_bit(FLAG_IS_HOGGED, &desc->flags);
ret = true;
}
@@ -2933,6 +2958,7 @@ static int gpio_set_config(struct gpio_chip *gc, unsigned offset,
unsigned arg;
switch (mode) {
+ case PIN_CONFIG_BIAS_DISABLE:
case PIN_CONFIG_BIAS_PULL_DOWN:
case PIN_CONFIG_BIAS_PULL_UP:
arg = 1;
@@ -2946,6 +2972,26 @@ static int gpio_set_config(struct gpio_chip *gc, unsigned offset,
return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
}
+static int gpio_set_bias(struct gpio_chip *chip, struct gpio_desc *desc)
+{
+ int bias = 0;
+ int ret = 0;
+
+ if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
+ bias = PIN_CONFIG_BIAS_DISABLE;
+ else if (test_bit(FLAG_PULL_UP, &desc->flags))
+ bias = PIN_CONFIG_BIAS_PULL_UP;
+ else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
+ bias = PIN_CONFIG_BIAS_PULL_DOWN;
+
+ if (bias) {
+ ret = gpio_set_config(chip, gpio_chip_hwgpio(desc), bias);
+ if (ret != -ENOTSUPP)
+ return ret;
+ }
+ return 0;
+}
+
/**
* gpiod_direction_input - set the GPIO direction to input
* @desc: GPIO to set to input
@@ -2990,15 +3036,10 @@ int gpiod_direction_input(struct gpio_desc *desc)
__func__);
return -EIO;
}
- if (ret == 0)
+ if (ret == 0) {
clear_bit(FLAG_IS_OUT, &desc->flags);
-
- if (test_bit(FLAG_PULL_UP, &desc->flags))
- gpio_set_config(chip, gpio_chip_hwgpio(desc),
- PIN_CONFIG_BIAS_PULL_UP);
- else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
- gpio_set_config(chip, gpio_chip_hwgpio(desc),
- PIN_CONFIG_BIAS_PULL_DOWN);
+ ret = gpio_set_bias(chip, desc);
+ }
trace_gpio_direction(desc_to_gpio(desc), 1, ret);
diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
index b8b10a409c7b..ca9bc1e4803c 100644
--- a/drivers/gpio/gpiolib.h
+++ b/drivers/gpio/gpiolib.h
@@ -110,6 +110,7 @@ struct gpio_desc {
#define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */
#define FLAG_PULL_UP 13 /* GPIO has pull up enabled */
#define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */
+#define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */
/* Connection label */
const char *label;
diff --git a/include/uapi/linux/gpio.h b/include/uapi/linux/gpio.h
index 39e6c7854d63..7cc21c3b0839 100644
--- a/include/uapi/linux/gpio.h
+++ b/include/uapi/linux/gpio.h
@@ -35,6 +35,7 @@ struct gpiochip_info {
#define GPIOLINE_FLAG_OPEN_SOURCE (1UL << 4)
#define GPIOLINE_FLAG_BIAS_PULL_UP (1UL << 5)
#define GPIOLINE_FLAG_BIAS_PULL_DOWN (1UL << 6)
+#define GPIOLINE_FLAG_BIAS_DISABLE (1UL << 7)
/**
* struct gpioline_info - Information about a certain GPIO line
@@ -66,6 +67,7 @@ struct gpioline_info {
#define GPIOHANDLE_REQUEST_OPEN_SOURCE (1UL << 4)
#define GPIOHANDLE_REQUEST_BIAS_PULL_UP (1UL << 5)
#define GPIOHANDLE_REQUEST_BIAS_PULL_DOWN (1UL << 6)
+#define GPIOHANDLE_REQUEST_BIAS_DISABLE (1UL << 7)
/**
* struct gpiohandle_request - Information about a GPIO handle request