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Message-Id: <20190713075259.243565-3-dmitry.torokhov@gmail.com>
Date: Sat, 13 Jul 2019 00:52:59 -0700
From: Dmitry Torokhov <dmitry.torokhov@...il.com>
To: Linus Walleij <linus.walleij@...aro.org>,
"Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
"Enrico Weigelt, metux IT consult" <info@...ux.net>
Cc: linux-input@...r.kernel.org, linux-gpio@...r.kernel.org,
linux-kernel@...r.kernel.org,
Andy Shevchenko <andy.shevchenko@...il.com>,
Heikki Krogerus <heikki.krogerus@...ux.intel.com>
Subject: [PATCH 2/2] gpiolib: add support for fetching descriptors from static properties
Now that static device properties understand notion of child nodes, let's
teach gpiolib to tie such children and machine GPIO descriptor tables.
We will continue using a single table for entire device, but instead of
using connection ID as a lookup key in the GPIO descriptor table directly,
we will perform additional translation: fwnode_get_named_gpiod() when
dealing with property_set-backed fwnodes will try parsing string property
with name matching connection ID and use result of the lookup as the key in
the table:
static const struct property_entry dev_child1_props[] __initconst = {
...
PROPERTY_ENTRY_STRING("gpios", "child-1-gpios"),
{ }
};
static struct gpiod_lookup_table dev_gpiod_table = {
.dev_id = "some-device",
.table = {
...
GPIO_LOOKUP_IDX("B", 1, "child-1-gpios", 1, GPIO_ACTIVE_LOW),
...
},
};
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
---
drivers/gpio/gpiolib.c | 108 ++++++++++++++++++++++++++++++-----------
1 file changed, 79 insertions(+), 29 deletions(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index e013d417a936..b6574febe2b8 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -4307,39 +4307,44 @@ struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
}
EXPORT_SYMBOL(gpiod_get_from_of_node);
-/**
- * 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 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 opaque firmware.
- *
- * 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.
- *
- * Returns:
- * On successful request the GPIO pin is configured in accordance with
- * provided @dflags.
- *
- * In case of error an ERR_PTR() is returned.
- */
-struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
- const char *propname, int index,
- enum gpiod_flags dflags,
- const char *label)
+static struct gpio_desc *
+software_node_get_gpiod(struct fwnode_handle *fwnode,
+ const char *propname, int index, unsigned long *flags)
+{
+ struct device *dev;
+ const char *con_id;
+
+ dev = software_node_get_linked_device(fwnode);
+ if (IS_ERR_OR_NULL(dev))
+ return ERR_PTR(-EINVAL);
+
+ if (fwnode_property_read_string(fwnode, propname, &con_id)) {
+ /*
+ * We could not find string mapping property name to
+ * entry in gpio lookup table. Let's see if we are
+ * dealing with firmware node corresponding to the
+ * device (and not a child node): for such nodes we can
+ * try doing lookup directly with property name.
+ */
+ if (fwnode_get_parent(fwnode))
+ return ERR_PTR(-ENOENT);
+
+ con_id = propname;
+ }
+
+ return gpiod_find(dev, con_id, index, flags);
+}
+
+static struct gpio_desc *__fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
+ const char *propname,
+ int index,
+ enum gpiod_flags dflags,
+ const char *label)
{
unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
struct gpio_desc *desc = ERR_PTR(-ENODEV);
int ret;
- if (!fwnode)
- return ERR_PTR(-EINVAL);
-
if (is_of_node(fwnode)) {
desc = gpiod_get_from_of_node(to_of_node(fwnode),
propname, index,
@@ -4355,9 +4360,13 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
acpi_gpio_update_gpiod_flags(&dflags, &info);
acpi_gpio_update_gpiod_lookup_flags(&lflags, &info);
+ } else if (is_software_node(fwnode)) {
+ desc = software_node_get_gpiod(fwnode, propname, index,
+ &lflags);
+ if (IS_ERR(desc))
+ return desc;
}
- /* Currently only ACPI takes this path */
ret = gpiod_request(desc, label);
if (ret)
return ERR_PTR(ret);
@@ -4370,6 +4379,47 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
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 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 opaque firmware.
+ *
+ * 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.
+ *
+ * Returns:
+ * On successful request the GPIO pin is configured in accordance with
+ * provided @dflags.
+ *
+ * In case of error an ERR_PTR() is returned.
+ */
+struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
+ const char *propname, int index,
+ enum gpiod_flags dflags,
+ const char *label)
+{
+ struct gpio_desc *desc;
+
+ if (!fwnode)
+ return ERR_PTR(-EINVAL);
+
+ desc = __fwnode_get_named_gpiod(fwnode, propname, index, dflags, label);
+ if (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT &&
+ !IS_ERR_OR_NULL(fwnode->secondary)) {
+ desc = __fwnode_get_named_gpiod(fwnode->secondary,
+ propname, index, dflags, label);
+ }
+
+ return desc;
+}
EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod);
/**
--
2.22.0.510.g264f2c817a-goog
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