summaryrefslogtreecommitdiff
path: root/drivers/acpi/property.c
diff options
context:
space:
mode:
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-11-04 01:28:56 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-11-04 21:58:21 +0100
commitb31384fa5de37a100507751dfb5c0a49d06cee67 (patch)
treefa0084d464b8cb3873c5e169d61ee3c7e8e5b3e6 /drivers/acpi/property.c
parentffdcd955c3078af3ce117edcfce80fde1a512bed (diff)
downloadlinux-sh-b31384fa5de37a100507751dfb5c0a49d06cee67.tar.gz
Driver core: Unified device properties interface for platform firmware
Add a uniform interface by which device drivers can request device properties from the platform firmware by providing a property name and the corresponding data type. The purpose of it is to help to write portable code that won't depend on any particular platform firmware interface. The following general helper functions are added: device_property_present() device_property_read_u8() device_property_read_u16() device_property_read_u32() device_property_read_u64() device_property_read_string() device_property_read_u8_array() device_property_read_u16_array() device_property_read_u32_array() device_property_read_u64_array() device_property_read_string_array() The first one allows the caller to check if the given property is present. The next 5 of them allow single-valued properties of various types to be retrieved in a uniform way. The remaining 5 are for reading properties with multiple values (arrays of either numbers or strings). The interface covers both ACPI and Device Trees. This change set includes material from Mika Westerberg and Aaron Lu. Signed-off-by: Aaron Lu <aaron.lu@intel.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/property.c')
-rw-r--r--drivers/acpi/property.c178
1 files changed, 178 insertions, 0 deletions
diff --git a/drivers/acpi/property.c b/drivers/acpi/property.c
index c4a3e800e82c..2541b1fd1fa5 100644
--- a/drivers/acpi/property.c
+++ b/drivers/acpi/property.c
@@ -362,3 +362,181 @@ int acpi_dev_get_property_reference(struct acpi_device *adev, const char *name,
return -EPROTO;
}
EXPORT_SYMBOL_GPL(acpi_dev_get_property_reference);
+
+int acpi_dev_prop_get(struct acpi_device *adev, const char *propname,
+ void **valptr)
+{
+ return acpi_dev_get_property(adev, propname, ACPI_TYPE_ANY,
+ (const union acpi_object **)valptr);
+}
+
+int acpi_dev_prop_read_single(struct acpi_device *adev, const char *propname,
+ enum dev_prop_type proptype, void *val)
+{
+ const union acpi_object *obj;
+ int ret;
+
+ if (!val)
+ return -EINVAL;
+
+ if (proptype >= DEV_PROP_U8 && proptype <= DEV_PROP_U64) {
+ ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_INTEGER, &obj);
+ if (ret)
+ return ret;
+
+ switch (proptype) {
+ case DEV_PROP_U8:
+ if (obj->integer.value > U8_MAX)
+ return -EOVERFLOW;
+ *(u8 *)val = obj->integer.value;
+ break;
+ case DEV_PROP_U16:
+ if (obj->integer.value > U16_MAX)
+ return -EOVERFLOW;
+ *(u16 *)val = obj->integer.value;
+ break;
+ case DEV_PROP_U32:
+ if (obj->integer.value > U32_MAX)
+ return -EOVERFLOW;
+ *(u32 *)val = obj->integer.value;
+ break;
+ default:
+ *(u64 *)val = obj->integer.value;
+ break;
+ }
+ } else if (proptype == DEV_PROP_STRING) {
+ ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_STRING, &obj);
+ if (ret)
+ return ret;
+
+ *(char **)val = obj->string.pointer;
+ } else {
+ ret = -EINVAL;
+ }
+ return ret;
+}
+
+static int acpi_copy_property_array_u8(const union acpi_object *items, u8 *val,
+ size_t nval)
+{
+ int i;
+
+ for (i = 0; i < nval; i++) {
+ if (items[i].type != ACPI_TYPE_INTEGER)
+ return -EPROTO;
+ if (items[i].integer.value > U8_MAX)
+ return -EOVERFLOW;
+
+ val[i] = items[i].integer.value;
+ }
+ return 0;
+}
+
+static int acpi_copy_property_array_u16(const union acpi_object *items,
+ u16 *val, size_t nval)
+{
+ int i;
+
+ for (i = 0; i < nval; i++) {
+ if (items[i].type != ACPI_TYPE_INTEGER)
+ return -EPROTO;
+ if (items[i].integer.value > U16_MAX)
+ return -EOVERFLOW;
+
+ val[i] = items[i].integer.value;
+ }
+ return 0;
+}
+
+static int acpi_copy_property_array_u32(const union acpi_object *items,
+ u32 *val, size_t nval)
+{
+ int i;
+
+ for (i = 0; i < nval; i++) {
+ if (items[i].type != ACPI_TYPE_INTEGER)
+ return -EPROTO;
+ if (items[i].integer.value > U32_MAX)
+ return -EOVERFLOW;
+
+ val[i] = items[i].integer.value;
+ }
+ return 0;
+}
+
+static int acpi_copy_property_array_u64(const union acpi_object *items,
+ u64 *val, size_t nval)
+{
+ int i;
+
+ for (i = 0; i < nval; i++) {
+ if (items[i].type != ACPI_TYPE_INTEGER)
+ return -EPROTO;
+
+ val[i] = items[i].integer.value;
+ }
+ return 0;
+}
+
+static int acpi_copy_property_array_string(const union acpi_object *items,
+ char **val, size_t nval)
+{
+ int i;
+
+ for (i = 0; i < nval; i++) {
+ if (items[i].type != ACPI_TYPE_STRING)
+ return -EPROTO;
+
+ val[i] = items[i].string.pointer;
+ }
+ return 0;
+}
+
+int acpi_dev_prop_read(struct acpi_device *adev, const char *propname,
+ enum dev_prop_type proptype, void *val, size_t nval)
+{
+ const union acpi_object *obj;
+ const union acpi_object *items;
+ int ret;
+
+ if (val && nval == 1) {
+ ret = acpi_dev_prop_read_single(adev, propname, proptype, val);
+ if (!ret)
+ return ret;
+ }
+
+ ret = acpi_dev_get_property_array(adev, propname, ACPI_TYPE_ANY, &obj);
+ if (ret)
+ return ret;
+
+ if (!val)
+ return obj->package.count;
+ else if (nval <= 0)
+ return -EINVAL;
+
+ if (nval > obj->package.count)
+ return -EOVERFLOW;
+
+ items = obj->package.elements;
+ switch (proptype) {
+ case DEV_PROP_U8:
+ ret = acpi_copy_property_array_u8(items, (u8 *)val, nval);
+ break;
+ case DEV_PROP_U16:
+ ret = acpi_copy_property_array_u16(items, (u16 *)val, nval);
+ break;
+ case DEV_PROP_U32:
+ ret = acpi_copy_property_array_u32(items, (u32 *)val, nval);
+ break;
+ case DEV_PROP_U64:
+ ret = acpi_copy_property_array_u64(items, (u64 *)val, nval);
+ break;
+ case DEV_PROP_STRING:
+ ret = acpi_copy_property_array_string(items, (char **)val, nval);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+ return ret;
+}