This change exposes ACPI device properties via sysfs under
<device>/firmware_node/properties/*. This is a logical extension of
the changes that expose _ADR, _STR, _HID, etc... in the same
directory.
Integer properties are represented by a file containing a single hex
number (printf format 0x%llx).
String properties are represented by a file containing a single
string.
Arrays of integers properties are represented by a file containing a
space delimited string of hex numbers (printf format 0x%llx).
Example:
0x1 0x2 0x3
Arrays of strings properties are represented by a file containing a
newline delimited string of escaped strings (printf format %*pE).
Example:
foo
bar
has\nnewline
Device reference properties are represented by a symlink to the
referenced device plus a <property>_args node containing an integer
array of reference arguments. In the case of multiple local
references, the references at index 1..N are represented the same way
using the naming convention <property><N>, <property><N>_args.
Examples:
(a property containing a single reference)
phy-handle -> ../../../device:00
phy-handle_args: 0x0
(a property containing three references)
ref -> ../device:01
ref_args: 0x1 0x2
ref1 -> ../device:02
ref1_args: 0x3 0x4
ref2 -> ../device:03
ref2_args: 0x5 0x6
The bulk of the credit for this idea and implementation goes to Dustin
Byford <dustin@xxxxxxxxxxxxxxxxxxx>. I only massaged it a little to
work with a more recent kernel version.
Signed-off-by: Curt Brune <curt@xxxxxxxxxxxxxxxxxxx>
---
Documentation/acpi/dsd/sysfs-properties.txt | 45 ++++
drivers/acpi/device_sysfs.c | 379 ++++++++++++++++++++++++++++
drivers/acpi/internal.h | 1 +
drivers/acpi/scan.c | 2 +
include/acpi/acpi_bus.h | 1 +
5 files changed, 428 insertions(+)
create mode 100644 Documentation/acpi/dsd/sysfs-properties.txt
diff --git a/Documentation/acpi/dsd/sysfs-properties.txt b/Documentation/acpi/dsd/sysfs-properties.txt
new file mode 100644
index 000000000000..c70fd5b52d47
--- /dev/null
+++ b/Documentation/acpi/dsd/sysfs-properties.txt
@@ -0,0 +1,45 @@
+ACPI device properties are exported via sysfs under
+<device>/firmware_node/properties/*. This is a logical extension of
+the changes that expose _ADR, _STR, _HID, etc... in the same
+directory.
+
+Integer properties are represented by a file containing a single hex
+number (printf format 0x%llx).
+
+String properties are represented by a file containing a single
+string.
+
+Arrays of integers properties are represented by a file containing a
+space delimited string of hex numbers (printf format 0x%llx).
+
+Example:
+ 0x1 0x2 0x3
+
+Arrays of strings properties are represented by a file containing a
+newline delimited string of escaped strings (printf format %*pE).
+
+Example:
+ foo
+ bar
+ has\nnewline
+
+Device reference properties are represented by a symlink to the
+referenced device plus a <property>_args node containing an integer
+array of reference arguments. In the case of multiple local
+references, the references at index 1..N are represented the same way
+using the naming convention <property><N>, <property><N>_args.
+
+Examples:
+ (a property containing a single reference)
+
+ phy-handle -> ../../../device:00
+ phy-handle_args: 0x0
+
+ (a property containing three references)
+
+ ref -> ../device:01
+ ref_args: 0x1 0x2
+ ref1 -> ../device:02
+ ref1_args: 0x3 0x4
+ ref2 -> ../device:03
+ ref2_args: 0x5 0x6
diff --git a/drivers/acpi/device_sysfs.c b/drivers/acpi/device_sysfs.c
index 24418932612e..ffc05b975cd2 100644
--- a/drivers/acpi/device_sysfs.c
+++ b/drivers/acpi/device_sysfs.c
@@ -26,6 +26,25 @@
#include "internal.h"
+static LIST_HEAD(acpi_deferred_property_list);
+struct acpi_deferred_property_link {
+ struct acpi_device *adev;
+ char *propname;
+ struct list_head list;
+};
+
+struct acpi_property_attribute {
+ struct attribute attr;
+ char *name;
+ int ref_idx;
+ ssize_t (*show)(struct kobject *kobj, struct device_attribute *attr,
+ char *buf);
+};
+
+#define to_acpi_property_attr(x) \
+ container_of(x, struct acpi_property_attribute, attr)
+
+
static ssize_t acpi_object_path(acpi_handle handle, char *buf)
{
struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
@@ -504,6 +523,360 @@ static ssize_t status_show(struct device *dev, struct device_attribute *attr,
}
static DEVICE_ATTR_RO(status);
+static inline
+int __acpi_dev_get_property_reference(const struct acpi_device *adev,
+ const char *propname, int index,
+ struct acpi_reference_args *args)
+{
+ return acpi_node_get_property_reference(&adev->fwnode,
+ propname,
+ index,
+ args);
+}
+
+static ssize_t __acpi_property_show_ref_args(struct acpi_device *adev,
+ char *name, int idx, char *buf)
+{
+ struct acpi_reference_args args;
+ char *out;
+ int err;
+ int arg;
+
+ err = __acpi_dev_get_property_reference(adev, name, idx, &args);
+ if (err)
+ return err;
+
+ out = buf;
+ for (arg = 0; arg < args.nargs; arg++) {
+ err = sprintf(out, "0x%llx ", args.args[arg]);
+ if (err < 0)
+ return err;
+
+ out += err;
+ }
+
+ *(out - 1) = '\n';
+ return out - buf;
+}
+
+static ssize_t __acpi_property_print_scalar(char *buf,
+ const union acpi_object *obj,
+ size_t size)
+{
+ switch (obj->type) {
+ case ACPI_TYPE_INTEGER:
+ return snprintf(buf, size, "0x%llx ", obj->integer.value);
+ case ACPI_TYPE_STRING:
+ return snprintf(buf, size, "%*pE\n",
+ (int)strlen(obj->string.pointer),
+ obj->string.pointer);
+ default:
+ return -EPROTO;
+ }
+}
+
+static ssize_t __acpi_property_show(struct acpi_device *adev, char *propname,
+ char *buf)
+{
+ static const int max = PAGE_SIZE - 2;
+ const union acpi_object *obj;
+ char *out;
+ int err;
+
+ err = acpi_dev_get_property(adev, propname, ACPI_TYPE_ANY, &obj);
+ if (err)
+ return err;
+
+ out = buf;
+ if (obj->type == ACPI_TYPE_PACKAGE) {
+ int element;
+
+ for (element = 0; element < obj->package.count; element++) {
+ err = __acpi_property_print_scalar(out,
+ &obj->package.elements[element],
+ max - (out - buf));
+ if (err < 0)
+ return err;
+ out += err;
+ }
+ } else {
+ err = __acpi_property_print_scalar(out, obj, max);
+ if (err < 0)
+ return err;
+
+ out += err;
+ }
+
+ *(out - 1) = '\n';
+ return out - buf;
+}
+
+static ssize_t acpi_property_show(struct kobject *kobj,
+ struct attribute *attr,
+ char *buf)
+{
+ struct device *dev = kobj_to_dev(kobj->parent);
+ struct acpi_device *adev = to_acpi_device(dev);
+ struct acpi_property_attribute *prop_attr = to_acpi_property_attr(attr);
+
+ if (prop_attr->ref_idx >= 0)
+ return __acpi_property_show_ref_args(adev, prop_attr->name,
+ prop_attr->ref_idx, buf);
+ else
+ return __acpi_property_show(adev, prop_attr->name, buf);
+}
+
+static const struct sysfs_ops acpi_property_sysfs_ops = {
+ .show = acpi_property_show,
+};
+
+static struct kobj_type acpi_property_ktype = {
+ .sysfs_ops = &acpi_property_sysfs_ops,
+};
+
+static int acpi_property_create_file(struct acpi_device *adev,
+ char *propname, char *filename,
+ int ref_idx)
+{
+ struct acpi_property_attribute *prop_attr;
+ int err;
+
+ prop_attr = devm_kzalloc(&adev->dev, sizeof(*prop_attr), GFP_KERNEL);
+ if (!prop_attr)
+ return -ENOMEM;
+
+ prop_attr->name = propname;
+ prop_attr->ref_idx = ref_idx;
+ sysfs_attr_init(&prop_attr->attr);
+ prop_attr->attr.name = filename;
+ prop_attr->attr.mode = 0444;
+
+ err = sysfs_create_file(&adev->data.kobj, &prop_attr->attr);
+ if (err) {
+ dev_err(&adev->dev, "failed to create property file: %s\n",
+ filename);
+ devm_kfree(&adev->dev, prop_attr);
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+int acpi_property_add_deferred(void)
+{
+ struct acpi_deferred_property_link *link, *tmp;
+ int idx;
+ int resolved = 0;
+ int scanned = 0;
+
+ if (list_empty(&acpi_deferred_property_list))
+ return 0;
+
+ list_for_each_entry_safe(link, tmp, &acpi_deferred_property_list,
+ list) {
+ struct acpi_reference_args args;
+ int err;
+
+ scanned++;
+
+ idx = 0;
+ while (true) {
+ char *sysfs_name;
+ err = __acpi_dev_get_property_reference(link->adev,
+ link->propname,
+ idx,
+ &args);
+ if (err)
+ break;
+
+ if (idx == 0)
+ sysfs_name = devm_kasprintf(&link->adev->dev,
+ GFP_KERNEL, "%s",
+ link->propname);
+ else
+ sysfs_name = devm_kasprintf(&link->adev->dev,
+ GFP_KERNEL, "%s%u",
+ link->propname,
+ idx);
+ if (!sysfs_name)
+ return -ENOMEM;
+
+ err = sysfs_create_link(&link->adev->data.kobj,
+ &args.adev->dev.kobj,
+ sysfs_name);
+ if (err)
+ return err;
+
+ dev_dbg(&link->adev->dev,
+ "created deferred property link: %s\n",
+ sysfs_name);
+
+ if (args.nargs > 0) {
+ char *sysfs_args_name;
+
+ sysfs_args_name = devm_kasprintf(&link->adev->dev,
+ GFP_KERNEL,
+ "%s_args",
+ sysfs_name);
+ if (!sysfs_args_name)
+ return -ENOMEM;
+
+ err = acpi_property_create_file(link->adev,
+ link->propname,
+ sysfs_args_name,
+ idx);
+ if (err)
+ return err;
+
+ dev_dbg(&link->adev->dev,
+ "created deferred property args: %s\n",
+ sysfs_args_name);
+ }
+
+ idx++;
+ }
+ list_del(&link->list);
+ devm_kfree(&link->adev->dev, link);
+ resolved++;
+ }
+
+ pr_debug("acpi: resolved %d of %d deferred property links\n",
+ resolved, scanned);
+
+ return resolved;
+}
+
+static int acpi_property_defer(struct acpi_device *adev,
+ const union acpi_object *property)
+{
+ char *propname;
+ struct acpi_deferred_property_link *link;
+
+ propname = property->package.elements[0].string.pointer;
+
+ dev_dbg(&adev->dev,
+ "deferring property add for ref %s\n", propname);
+
+ link = devm_kmalloc(&adev->dev, sizeof(*link), GFP_KERNEL);
+ if (!link)
+ return -ENOMEM;
+
+ link->adev = adev;
+ link->propname = propname;
+ list_add_tail(&link->list,
+ &acpi_deferred_property_list);
+
+ return 0;
+}
+
+static int acpi_property_add(struct acpi_device *adev,
+ const union acpi_object *property)
+{
+ char *propname;
+
+ propname = property->package.elements[0].string.pointer;
+
+ if ((property->package.elements[1].type == ACPI_TYPE_PACKAGE) ||
+ (property->package.elements[1].type == ACPI_TYPE_LOCAL_REFERENCE))
+ return acpi_property_defer(adev, property);
+ else
+ return acpi_property_create_file(adev, propname, propname, -1);
+}
+
+static void acpi_property_remove_attr(struct acpi_device *adev,
+ const char *property)
+{
+ struct attribute attr = { 0 };
+ const union acpi_object *obj;
+ struct acpi_reference_args args;
+ char *sysfs_name;
+ int idx;
+ int err;
+
+ err = acpi_dev_get_property(adev, property, ACPI_TYPE_ANY, &obj);
+ if (err)
+ return;
+
+ attr.name = property;
+ sysfs_remove_file(&adev->data.kobj, &attr);
+
+ idx = 0;
+ while (__acpi_dev_get_property_reference(adev, property, idx,
+ &args) == 0) {
+ if (idx == 0)
+ sysfs_name = kasprintf(GFP_KERNEL, "%s", property);
+ else
+ sysfs_name = kasprintf(GFP_KERNEL, "%s%u", property,
+ idx);
+ if (!sysfs_name)
+ continue;
+
+ sysfs_remove_link(&adev->data.kobj, sysfs_name);
+ kfree(sysfs_name);
+
+ if (args.nargs > 0) {
+ attr.name = kasprintf(GFP_KERNEL, "%s_args",
+ sysfs_name);
+ if (!attr.name)
+ continue;
+
+ sysfs_remove_file(&adev->data.kobj, &attr);
+ kfree(attr.name);
+ }
+
+ idx++;
+ }
+}
+
+static int acpi_add_properties(struct acpi_device *adev)
+{
+ const union acpi_object *properties;
+ int err;
+ int i;
+
+ if (!adev->data.pointer || !adev->data.properties)
+ return -EINVAL;
+
+ properties = adev->data.properties;
+ err = kobject_init_and_add(&adev->data.kobj, &acpi_property_ktype,
+ &adev->dev.kobj, "properties");
+ if (err)
+ return err;
+
+ for (i = 0; i < properties->package.count; i++) {
+ const union acpi_object *property;
+
+ property = &properties->package.elements[i];
+ err = acpi_property_add(adev, property);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+static void acpi_remove_properties(struct acpi_device *adev)
+{
+ const union acpi_object *properties;
+ int i;
+
+ if (!adev->data.pointer || !adev->data.properties)
+ return;
+
+ properties = adev->data.properties;
+ for (i = 0; i < properties->package.count; i++) {
+ const union acpi_object *property;
+ const union acpi_object *propname;
+
+ property = &properties->package.elements[i];
+ propname = &property->package.elements[0];
+
+ acpi_property_remove_attr(adev, propname->string.pointer);
+ }
+
+ kobject_put(&adev->data.kobj);
+}
+
/**
* acpi_device_setup_files - Create sysfs attributes of an ACPI device.
* @dev: ACPI device object.
@@ -592,6 +965,9 @@ int acpi_device_setup_files(struct acpi_device *dev)
acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
+ if (dev->data.of_compatible)
+ acpi_add_properties(dev);
+
end:
return result;
}
@@ -604,6 +980,9 @@ void acpi_device_remove_files(struct acpi_device *dev)
{
acpi_hide_nondev_subnodes(&dev->data);
+ if (dev->data.of_compatible)
+ acpi_remove_properties(dev);
+
if (dev->flags.power_manageable) {
device_remove_file(&dev->dev, &dev_attr_power_state);
if (dev->power.flags.power_resources)
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 4361c4415b4f..d0d21cf77e32 100644
--- a/drivers/acpi/internal.h
+++ b/drivers/acpi/internal.h
@@ -231,6 +231,7 @@ static inline void suspend_nvs_restore(void) {}
void acpi_init_properties(struct acpi_device *adev);
void acpi_free_properties(struct acpi_device *adev);
+int acpi_property_add_deferred(void);
#ifdef CONFIG_X86
void acpi_extract_apple_properties(struct acpi_device *adev);
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 602f8ff212f2..84b8257d38a4 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -2009,6 +2009,8 @@ int acpi_bus_scan(acpi_handle handle)
acpi_bus_check_add, NULL, NULL, &device);
if (device) {
+ while (acpi_property_add_deferred() > 0)
+ ;
acpi_bus_attach(device);
return 0;
}
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index fa1505292f6c..73041ceb7736 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -344,6 +344,7 @@ struct acpi_device_physical_node {
/* ACPI Device Specific Data (_DSD) */
struct acpi_device_data {
+ struct kobject kobj;
const union acpi_object *pointer;
const union acpi_object *properties;
const union acpi_object *of_compatible;
--
2.1.4
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