[PATCH 6/6] ACPI / property: Extend device_get_next_child_node() to data-only nodes

From: Rafael J. Wysocki
Date: Wed Aug 26 2015 - 22:16:10 EST

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From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

Make device_get_next_child_node() work with ACPI data-only subnodes
introduced previously.

Namely, replace acpi_get_next_child() with acpi_get_next_subnode()
that can handle (and return) child device objects as well as child
data-only subnodes of the given device and modify the ACPI part
of the GPIO subsystem to handle data-only subnodes returned by it.

To that end, introduce acpi_node_get_gpiod() taking a struct
fwnode_handle pointer as the first argument. That argument may
point to an ACPI device object as well as to a data-only subnode
and the function should do the right thing (ie. look for the matching
GPIO descriptor correctly) in either case.

Next, modify fwnode_get_named_gpiod() to use acpi_node_get_gpiod()
instead of acpi_get_gpiod_by_index() which automatically causes
devm_get_gpiod_from_child() to work with ACPI data-only subnodes
that may be returned by device_get_next_child_node() which in turn
is required by the users of that function (the gpio_keys_polled
and gpio-leds drivers).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Tested-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
---
drivers/acpi/property.c | 88 ++++++++++++++++++++++++++++++++++++++++----
drivers/acpi/scan.c | 20 ----------
drivers/base/property.c | 6 ---
drivers/gpio/gpiolib-acpi.c | 58 ++++++++++++++++++++++++++---
drivers/gpio/gpiolib.c | 5 +-
drivers/gpio/gpiolib.h | 10 ++++-
include/linux/acpi.h | 17 ++++----
7 files changed, 153 insertions(+), 51 deletions(-)

Index: linux-pm/drivers/acpi/property.c
===================================================================
--- linux-pm.orig/drivers/acpi/property.c
+++ linux-pm/drivers/acpi/property.c
@@ -461,9 +461,9 @@ static int acpi_data_get_property_array(
}

/**
- * acpi_dev_get_property_reference - returns handle to the referenced object
- * @adev: ACPI device to get property
- * @name: Name of the property
+ * acpi_data_get_property_reference - returns handle to the referenced object
+ * @data: ACPI device data object containing the property
+ * @propname: Name of the property
* @index: Index of the reference to return
* @args: Location to store the returned reference with optional arguments
*
@@ -477,16 +477,16 @@ static int acpi_data_get_property_array(
*
* Return: %0 on success, negative error code on failure.
*/
-int acpi_dev_get_property_reference(struct acpi_device *adev,
- const char *name, size_t index,
- struct acpi_reference_args *args)
+static int acpi_data_get_property_reference(struct acpi_device_data *data,
+ const char *propname, size_t index,
+ struct acpi_reference_args *args)
{
const union acpi_object *element, *end;
const union acpi_object *obj;
struct acpi_device *device;
int ret, idx = 0;

- ret = acpi_dev_get_property(adev, name, ACPI_TYPE_ANY, &obj);
+ ret = acpi_data_get_property(data, propname, ACPI_TYPE_ANY, &obj);
if (ret)
return ret;

@@ -561,7 +561,23 @@ int acpi_dev_get_property_reference(stru

return -EPROTO;
}
-EXPORT_SYMBOL_GPL(acpi_dev_get_property_reference);
+
+/**
+ * acpi_node_get_property_reference - get a handle to the referenced object.
+ * @fwnode: Firmware node to get the property from.
+ * @propname: Name of the property.
+ * @index: Index of the reference to return.
+ * @args: Location to store the returned reference with optional arguments.
+ */
+int acpi_node_get_property_reference(struct fwnode_handle *fwnode,
+ const char *name, size_t index,
+ struct acpi_reference_args *args)
+{
+ struct acpi_device_data *data = acpi_device_data_of_node(fwnode);
+
+ return data ? acpi_data_get_property_reference(data, name, index, args) : -EINVAL;
+}
+EXPORT_SYMBOL_GPL(acpi_node_get_property_reference);

static int acpi_data_prop_read_single(struct acpi_device_data *data,
const char *propname,
@@ -767,3 +783,59 @@ int acpi_node_prop_read(struct fwnode_ha
return acpi_data_prop_read(acpi_device_data_of_node(fwnode),
propname, proptype, val, nval);
}
+
+/**
+ * acpi_get_next_subnode - Return the next child node handle for a device.
+ * @dev: Device to find the next child node for.
+ * @child: Handle to one of the device's child nodes or a null handle.
+ */
+struct fwnode_handle *acpi_get_next_subnode(struct device *dev,
+ struct fwnode_handle *child)
+{
+ struct acpi_device *adev = ACPI_COMPANION(dev);
+ struct list_head *head, *next;
+
+ if (!adev)
+ return NULL;
+
+ if (!child || child->type == FWNODE_ACPI) {
+ head = &adev->children;
+ if (list_empty(head))
+ goto nondev;
+
+ if (child) {
+ adev = to_acpi_device_node(child);
+ next = adev->node.next;
+ if (next == head) {
+ child = NULL;
+ goto nondev;
+ }
+ adev = list_entry(next, struct acpi_device, node);
+ } else {
+ adev = list_first_entry(head, struct acpi_device, node);
+ }
+ return acpi_fwnode_handle(adev);
+ }
+
+ nondev:
+ if (!child || child->type == FWNODE_ACPI_DATA) {
+ struct acpi_data_node *dn;
+
+ head = &adev->data.subnodes;
+ if (list_empty(head))
+ return NULL;
+
+ if (child) {
+ dn = to_acpi_data_node(child);
+ next = dn->sibling.next;
+ if (next == head)
+ return NULL;
+
+ dn = list_entry(next, struct acpi_data_node, sibling);
+ } else {
+ dn = list_first_entry(head, struct acpi_data_node, sibling);
+ }
+ return &dn->fwnode;
+ }
+ return NULL;
+}
Index: linux-pm/drivers/base/property.c
===================================================================
--- linux-pm.orig/drivers/base/property.c
+++ linux-pm/drivers/base/property.c
@@ -481,11 +481,7 @@ struct fwnode_handle *device_get_next_ch
if (node)
return &node->fwnode;
} else if (IS_ENABLED(CONFIG_ACPI)) {
- struct acpi_device *node;
-
- node = acpi_get_next_child(dev, to_acpi_device_node(child));
- if (node)
- return acpi_fwnode_handle(node);
+ return acpi_get_next_subnode(dev, child);
}
return NULL;
}
Index: linux-pm/include/linux/acpi.h
===================================================================
--- linux-pm.orig/include/linux/acpi.h
+++ linux-pm/include/linux/acpi.h
@@ -758,9 +758,9 @@ struct acpi_reference_args {
#ifdef CONFIG_ACPI
int acpi_dev_get_property(struct acpi_device *adev, const char *name,
acpi_object_type type, const union acpi_object **obj);
-int acpi_dev_get_property_reference(struct acpi_device *adev,
- const char *name, size_t index,
- struct acpi_reference_args *args);
+int acpi_node_get_property_reference(struct fwnode_handle *fwnode,
+ const char *name, size_t index,
+ struct acpi_reference_args *args);

int acpi_node_prop_get(struct fwnode_handle *fwnode, const char *propname,
void **valptr);
@@ -771,8 +771,8 @@ int acpi_node_prop_read(struct fwnode_ha
int acpi_dev_prop_read(struct acpi_device *adev, const char *propname,
enum dev_prop_type proptype, void *val, size_t nval);

-struct acpi_device *acpi_get_next_child(struct device *dev,
- struct acpi_device *child);
+struct fwnode_handle *acpi_get_next_subnode(struct device *dev,
+ struct fwnode_handle *subnode);
#else
static inline int acpi_dev_get_property(struct acpi_device *adev,
const char *name, acpi_object_type type,
@@ -781,7 +781,7 @@ static inline int acpi_dev_get_property(
return -ENXIO;
}

-static inline int acpi_dev_get_property_reference(struct acpi_device *adev,
+static inline int acpi_node_get_property_reference(struct fwnode_handle *fwnode,
const char *name, const char *cells_name,
size_t index, struct acpi_reference_args *args)
{
@@ -826,12 +826,11 @@ static inline int acpi_dev_prop_read(str
return -ENXIO;
}

-static inline struct acpi_device *acpi_get_next_child(struct device *dev,
- struct acpi_device *child)
+static inline struct fwnode_handle *acpi_get_next_subnode(struct device *dev,
+ struct fwnode_handle *subnode)
{
return NULL;
}
-
#endif

#endif /*_LINUX_ACPI_H*/
Index: linux-pm/drivers/gpio/gpiolib.c
===================================================================
--- linux-pm.orig/drivers/gpio/gpiolib.c
+++ linux-pm/drivers/gpio/gpiolib.c
@@ -2056,11 +2056,10 @@ struct gpio_desc *fwnode_get_named_gpiod
&flags);
if (!IS_ERR(desc))
active_low = flags & OF_GPIO_ACTIVE_LOW;
- } else if (is_acpi_device_node(fwnode)) {
+ } else if (is_acpi_node(fwnode)) {
struct acpi_gpio_info info;

- desc = acpi_get_gpiod_by_index(to_acpi_device_node(fwnode),
- propname, 0, &info);
+ desc = acpi_node_get_gpiod(fwnode, propname, 0, &info);
if (!IS_ERR(desc))
active_low = info.active_low;
}
Index: linux-pm/drivers/gpio/gpiolib-acpi.c
===================================================================
--- linux-pm.orig/drivers/gpio/gpiolib-acpi.c
+++ linux-pm/drivers/gpio/gpiolib-acpi.c
@@ -453,7 +453,7 @@ static int acpi_gpio_resource_lookup(str
return 0;
}

-static int acpi_gpio_property_lookup(struct acpi_device *adev,
+static int acpi_gpio_property_lookup(struct fwnode_handle *fwnode,
const char *propname, int index,
struct acpi_gpio_lookup *lookup)
{
@@ -461,10 +461,16 @@ static int acpi_gpio_property_lookup(str
int ret;

memset(&args, 0, sizeof(args));
- ret = acpi_dev_get_property_reference(adev, propname, index, &args);
- if (ret && !acpi_get_driver_gpio_data(adev, propname, index, &args))
- return ret;
+ ret = acpi_node_get_property_reference(fwnode, propname, index, &args);
+ if (ret) {
+ struct acpi_device *adev = to_acpi_device_node(fwnode);

+ if (!adev)
+ return ret;
+
+ if (!acpi_get_driver_gpio_data(adev, propname, index, &args))
+ return ret;
+ }
/*
* The property was found and resolved, so need to lookup the GPIO based
* on returned args.
@@ -518,7 +524,8 @@ struct gpio_desc *acpi_get_gpiod_by_inde
if (propname) {
dev_dbg(&adev->dev, "GPIO: looking up %s\n", propname);

- ret = acpi_gpio_property_lookup(adev, propname, index, &lookup);
+ ret = acpi_gpio_property_lookup(acpi_fwnode_handle(adev),
+ propname, index, &lookup);
if (ret)
return ERR_PTR(ret);

@@ -532,6 +539,47 @@ struct gpio_desc *acpi_get_gpiod_by_inde

ret = acpi_gpio_resource_lookup(&lookup, info);
return ret ? ERR_PTR(ret) : lookup.desc;
+}
+
+/**
+ * acpi_node_get_gpiod() - get a GPIO descriptor from ACPI resources
+ * @fwnode: pointer to an ACPI firmware node to get the GPIO information from
+ * @propname: Property name of the GPIO
+ * @index: index of GpioIo/GpioInt resource (starting from %0)
+ * @info: info pointer to fill in (optional)
+ *
+ * If @fwnode is an ACPI device object, call %acpi_get_gpiod_by_index() for it.
+ * Otherwise (ie. it is a data-only non-device object), use the property-based
+ * GPIO lookup to get to the GPIO resource with the relevant information and use
+ * that to obtain the GPIO descriptor to return.
+ */
+struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
+ const char *propname, int index,
+ struct acpi_gpio_info *info)
+{
+ struct acpi_gpio_lookup lookup;
+ struct acpi_device *adev;
+ int ret;
+
+ adev = to_acpi_device_node(fwnode);
+ if (adev)
+ return acpi_get_gpiod_by_index(adev, propname, index, info);
+
+ if (!is_acpi_data_node(fwnode))
+ return ERR_PTR(-ENODEV);
+
+ if (!propname)
+ return ERR_PTR(-EINVAL);
+
+ memset(&lookup, 0, sizeof(lookup));
+ lookup.index = index;
+
+ ret = acpi_gpio_property_lookup(fwnode, propname, index, &lookup);
+ if (ret)
+ return ERR_PTR(ret);
+
+ ret = acpi_gpio_resource_lookup(&lookup, info);
+ return ret ? ERR_PTR(ret) : lookup.desc;
}

/**
Index: linux-pm/drivers/gpio/gpiolib.h
===================================================================
--- linux-pm.orig/drivers/gpio/gpiolib.h
+++ linux-pm/drivers/gpio/gpiolib.h
@@ -42,6 +42,9 @@ void acpi_gpiochip_free_interrupts(struc
struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
const char *propname, int index,
struct acpi_gpio_info *info);
+struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
+ const char *propname, int index,
+ struct acpi_gpio_info *info);

int acpi_gpio_count(struct device *dev, const char *con_id);
#else
@@ -60,7 +63,12 @@ acpi_get_gpiod_by_index(struct acpi_devi
{
return ERR_PTR(-ENOSYS);
}
-
+static inline struct gpio_desc *
+acpi_node_get_gpiod(struct fwnode_handle *fwnode, const char *propname,
+ int index, struct acpi_gpio_info *info)
+{
+ return ERR_PTR(-ENXIO);
+}
static inline int acpi_gpio_count(struct device *dev, const char *con_id)
{
return -ENODEV;
Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -695,26 +695,6 @@ int acpi_device_add(struct acpi_device *
return result;
}

-struct acpi_device *acpi_get_next_child(struct device *dev,
- struct acpi_device *child)
-{
- struct acpi_device *adev = ACPI_COMPANION(dev);
- struct list_head *head, *next;
-
- if (!adev)
- return NULL;
-
- head = &adev->children;
- if (list_empty(head))
- return NULL;
-
- if (!child)
- return list_first_entry(head, struct acpi_device, node);
-
- next = child->node.next;
- return next == head ? NULL : list_entry(next, struct acpi_device, node);
-}
-
/* --------------------------------------------------------------------------
Device Enumeration
-------------------------------------------------------------------------- */

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Next message: Rafael J. Wysocki: "[PATCH 1/6] ACPI / property: Add routine for extraction of _DSD properties"
Previous message: Rafael J. Wysocki: "[PATCH 0/6] ACPI / properties: Hierarchical properties support"
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Next in thread: Rafael J. Wysocki: "[PATCH 1/6] ACPI / property: Add routine for extraction of _DSD properties"
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