Add new flags to allow users to specify that they are not concerned with
the status of GPIOs whilst in a sleep/low power state.
Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
Acked-by: Rob Herring <robh@xxxxxxxxxx>
---
Changes since v1:
- Added much more core support for the SLEEP_MAY_LOOSE_VALUE flag
- Moved dt-binding new defines down a few lines
Rob, I carried your Ack since I assume you only care about
the dt-bindings include, which has only had the previous
defines moved down a couple of lines. I hope that is ok.
Thanks,
Charles
drivers/gpio/gpiolib-of.c | 3 +++
drivers/gpio/gpiolib.c | 12 ++++++++++++
drivers/gpio/gpiolib.h | 1 +
include/dt-bindings/gpio/gpio.h | 4 ++++
include/linux/gpio/driver.h | 3 +++
include/linux/gpio/machine.h | 2 ++
include/linux/of_gpio.h | 1 +
7 files changed, 26 insertions(+)
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index b13b7c7..e2abf0e 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -153,6 +153,9 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
*flags |= GPIO_OPEN_SOURCE;
}
+ if (of_flags & OF_GPIO_SLEEP_MAY_LOOSE_VALUE)
+ *flags |= GPIO_SLEEP_MAY_LOOSE_VALUE;
+
return desc;
}
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 5db4413..3cdddf4 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2869,6 +2869,16 @@ bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset)
}
EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
+bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset)
+{
+ if (offset >= chip->ngpio)
+ return false;
+
+ return !test_bit(FLAG_SLEEP_MAY_LOOSE_VALUE,
+ &chip->gpiodev->descs[offset].flags);
+}
+EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
+
/**
* gpiod_get_raw_value_cansleep() - return a gpio's raw value
* @desc: gpio whose value will be returned
@@ -3223,6 +3233,8 @@ static int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
if (lflags & GPIO_OPEN_SOURCE)
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
+ if (lflags & GPIO_SLEEP_MAY_LOOSE_VALUE)
+ set_bit(FLAG_SLEEP_MAY_LOOSE_VALUE, &desc->flags);
/* No particular flag request, return here... */
if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
index 2495b7e..f74b8a7 100644
--- a/drivers/gpio/gpiolib.h
+++ b/drivers/gpio/gpiolib.h
@@ -190,6 +190,7 @@ struct gpio_desc {
#define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */
#define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
#define FLAG_IS_HOGGED 11 /* GPIO is hogged */
+#define FLAG_SLEEP_MAY_LOOSE_VALUE 12 /* GPIO may loose value in sleep */
/* Connection label */
const char *label;
diff --git a/include/dt-bindings/gpio/gpio.h b/include/dt-bindings/gpio/gpio.h
index b4f54da..c507458 100644
--- a/include/dt-bindings/gpio/gpio.h
+++ b/include/dt-bindings/gpio/gpio.h
@@ -28,4 +28,8 @@
#define GPIO_OPEN_DRAIN (GPIO_SINGLE_ENDED | GPIO_LINE_OPEN_DRAIN)
#define GPIO_OPEN_SOURCE (GPIO_SINGLE_ENDED | GPIO_LINE_OPEN_SOURCE)
+/* Bit 3 express GPIO suspend/resume persistence */
+#define GPIO_SLEEP_MAINTAIN_VALUE 0
+#define GPIO_SLEEP_MAY_LOOSE_VALUE 8
+
#endif
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index 3935828..af20369 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -213,6 +213,9 @@ bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset);
bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset);
bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset);
+/* Sleep persistence inquiry for drivers */
+bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset);
+
/* get driver data */
void *gpiochip_get_data(struct gpio_chip *chip);
diff --git a/include/linux/gpio/machine.h b/include/linux/gpio/machine.h
index c0d712d..13adadf 100644
--- a/include/linux/gpio/machine.h
+++ b/include/linux/gpio/machine.h
@@ -9,6 +9,8 @@ enum gpio_lookup_flags {
GPIO_ACTIVE_LOW = (1 << 0),
GPIO_OPEN_DRAIN = (1 << 1),
GPIO_OPEN_SOURCE = (1 << 2),
+ GPIO_SLEEP_MAINTAIN_VALUE = (0 << 3),
+ GPIO_SLEEP_MAY_LOOSE_VALUE = (1 << 3),
};
/**
diff --git a/include/linux/of_gpio.h b/include/linux/of_gpio.h
index 1e089d5..ca10f43 100644
--- a/include/linux/of_gpio.h
+++ b/include/linux/of_gpio.h
@@ -31,6 +31,7 @@ enum of_gpio_flags {
OF_GPIO_ACTIVE_LOW = 0x1,
OF_GPIO_SINGLE_ENDED = 0x2,
OF_GPIO_OPEN_DRAIN = 0x4,
+ OF_GPIO_SLEEP_MAY_LOOSE_VALUE = 0x8,
};
#ifdef CONFIG_OF_GPIO
--
2.1.4
--
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