Sometimes a GPIO needs to be taken from a node without a device associated with it. The fwnode accessor does this, let's however break out the DT code for now.
Signed-off-by: Linus Walleij <[email protected]> --- drivers/gpio/gpiolib.c | 117 +++++++++++++++++++++++++++++++++++-------------- 1 file changed, 83 insertions(+), 34 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index aad84a6306c4..294c255e6227 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -3629,18 +3629,83 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev, } EXPORT_SYMBOL_GPL(gpiod_get_index); +/** + * gpiod_get_from_of_node() - obtain a GPIO from an OF node + * @node: handle of the OF node + * @propname: name of the DT property representing the GPIO + * @index: index of the GPIO to obtain for the consumer + * @dflags: GPIO initialization flags + * @label: label to attach to the requested GPIO + * + * Returns: + * On successful request the GPIO pin is configured in accordance with + * provided @dflags. If the node does not have the requested GPIO + * property, NULL is returned. + * + * In case of error an ERR_PTR() is returned. + */ +static struct gpio_desc *gpiod_get_from_of_node(struct device_node *node, + const char *propname, int index, + enum gpiod_flags dflags, + const char *label) +{ + struct gpio_desc *desc = ERR_PTR(-ENODEV); + unsigned long lflags = 0; + enum of_gpio_flags flags; + bool active_low = false; + bool single_ended = false; + bool open_drain = false; + int ret; + + desc = of_get_named_gpiod_flags(node, propname, + index, &flags); + + if (!desc || IS_ERR(desc)) { + /* If it is not there, just return NULL */ + if (PTR_ERR(desc) == -ENOENT) + return NULL; + return desc; + } + + active_low = flags & OF_GPIO_ACTIVE_LOW; + single_ended = flags & OF_GPIO_SINGLE_ENDED; + open_drain = flags & OF_GPIO_OPEN_DRAIN; + + ret = gpiod_request(desc, label); + if (ret) + return ERR_PTR(ret); + + if (active_low) + lflags |= GPIO_ACTIVE_LOW; + + if (single_ended) { + if (open_drain) + lflags |= GPIO_OPEN_DRAIN; + else + lflags |= GPIO_OPEN_SOURCE; + } + + ret = gpiod_configure_flags(desc, propname, lflags, dflags); + if (ret < 0) { + gpiod_put(desc); + return ERR_PTR(ret); + } + + return desc; +} + /** * fwnode_get_named_gpiod - obtain a GPIO from firmware node * @fwnode: handle of the firmware node * @propname: name of the firmware property representing the GPIO - * @index: index of the GPIO to obtain in the consumer + * @index: index of the GPIO to obtain for the consumer * @dflags: GPIO initialization flags * @label: label to attach to the requested GPIO * * This function can be used for drivers that get their configuration - * from firmware. + * from opaque firmware. * - * Function properly finds the corresponding GPIO using whatever is the + * The function properly finds the corresponding GPIO using whatever is the * underlying firmware interface and then makes sure that the GPIO * descriptor is requested before it is returned to the caller. * @@ -3657,53 +3722,37 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, { struct gpio_desc *desc = ERR_PTR(-ENODEV); unsigned long lflags = 0; - bool active_low = false; - bool single_ended = false; - bool open_drain = false; int ret; if (!fwnode) return ERR_PTR(-EINVAL); if (is_of_node(fwnode)) { - enum of_gpio_flags flags; - - desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, - index, &flags); - if (!IS_ERR(desc)) { - active_low = flags & OF_GPIO_ACTIVE_LOW; - single_ended = flags & OF_GPIO_SINGLE_ENDED; - open_drain = flags & OF_GPIO_OPEN_DRAIN; - } + desc = gpiod_get_from_of_node(to_of_node(fwnode), + propname, index, + dflags, + label); + return desc; } else if (is_acpi_node(fwnode)) { struct acpi_gpio_info info; desc = acpi_node_get_gpiod(fwnode, propname, index, &info); - if (!IS_ERR(desc)) { - active_low = info.polarity == GPIO_ACTIVE_LOW; - ret = acpi_gpio_update_gpiod_flags(&dflags, info.flags); - if (ret) - pr_debug("Override GPIO initialization flags\n"); - } - } + if (IS_ERR(desc)) + return desc; - if (IS_ERR(desc)) - return desc; + ret = acpi_gpio_update_gpiod_flags(&dflags, info.flags); + if (ret) + pr_debug("Override GPIO initialization flags\n"); + if (info.polarity == GPIO_ACTIVE_LOW) + lflags |= GPIO_ACTIVE_LOW; + } + + /* Currently only ACPI takes this path */ ret = gpiod_request(desc, label); if (ret) return ERR_PTR(ret); - if (active_low) - lflags |= GPIO_ACTIVE_LOW; - - if (single_ended) { - if (open_drain) - lflags |= GPIO_OPEN_DRAIN; - else - lflags |= GPIO_OPEN_SOURCE; - } - ret = gpiod_configure_flags(desc, propname, lflags, dflags); if (ret < 0) { gpiod_put(desc); -- 2.14.3
