gpio: Add new flags to control sleep status of GPIOs

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@opensource.wolfsonmicro.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Charles Keepax 2017-05-23 15:47:29 +01:00 committed by Linus Walleij
parent f9e3a419aa
commit 05f479bf7d
7 changed files with 26 additions and 0 deletions

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@ -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;
}

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@ -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
@ -3225,6 +3235,8 @@ 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)) {

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@ -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;

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@ -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

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@ -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);

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@ -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),
};
/**

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@ -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