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Message-Id: <20180109002727.22676-1-linus.walleij@linaro.org>
Date: Tue, 9 Jan 2018 01:27:27 +0100
From: Linus Walleij <linus.walleij@...aro.org>
To: Liam Girdwood <lgirdwood@...il.com>,
Mark Brown <broonie@...nel.org>, linux-gpio@...r.kernel.org,
Rob Herring <robh@...nel.org>
Cc: linux-kernel@...r.kernel.org,
Linus Walleij <linus.walleij@...aro.org>
Subject: [PATCH 2/4] gpio: Break out code to get a descriptor from a DT node
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 <linus.walleij@...aro.org>
---
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
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