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path: root/drivers/acpi/acpica/evregion.c
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Diffstat (limited to 'drivers/acpi/acpica/evregion.c')
-rw-r--r--drivers/acpi/acpica/evregion.c121
1 files changed, 119 insertions, 2 deletions
diff --git a/drivers/acpi/acpica/evregion.c b/drivers/acpi/acpica/evregion.c
index bea7223d7a71..f0edf5c43c03 100644
--- a/drivers/acpi/acpica/evregion.c
+++ b/drivers/acpi/acpica/evregion.c
@@ -55,6 +55,8 @@ static u8
acpi_ev_has_default_handler(struct acpi_namespace_node *node,
acpi_adr_space_type space_id);
+static void acpi_ev_orphan_ec_reg_method(void);
+
static acpi_status
acpi_ev_reg_run(acpi_handle obj_handle,
u32 level, void *context, void **return_value);
@@ -561,7 +563,9 @@ acpi_ev_detach_region(union acpi_operand_object *region_obj,
/* Now stop region accesses by executing the _REG method */
- status = acpi_ev_execute_reg_method(region_obj, 0);
+ status =
+ acpi_ev_execute_reg_method(region_obj,
+ ACPI_REG_DISCONNECT);
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status,
"from region _REG, [%s]",
@@ -1062,6 +1066,12 @@ acpi_ev_execute_reg_methods(struct acpi_namespace_node *node,
ACPI_NS_WALK_UNLOCK, acpi_ev_reg_run,
NULL, &space_id, NULL);
+ /* Special case for EC: handle "orphan" _REG methods with no region */
+
+ if (space_id == ACPI_ADR_SPACE_EC) {
+ acpi_ev_orphan_ec_reg_method();
+ }
+
return_ACPI_STATUS(status);
}
@@ -1120,6 +1130,113 @@ acpi_ev_reg_run(acpi_handle obj_handle,
return (AE_OK);
}
- status = acpi_ev_execute_reg_method(obj_desc, 1);
+ status = acpi_ev_execute_reg_method(obj_desc, ACPI_REG_CONNECT);
return (status);
}
+
+/*******************************************************************************
+ *
+ * FUNCTION: acpi_ev_orphan_ec_reg_method
+ *
+ * PARAMETERS: None
+ *
+ * RETURN: None
+ *
+ * DESCRIPTION: Execute an "orphan" _REG method that appears under the EC
+ * device. This is a _REG method that has no corresponding region
+ * within the EC device scope. The orphan _REG method appears to
+ * have been enabled by the description of the ECDT in the ACPI
+ * specification: "The availability of the region space can be
+ * detected by providing a _REG method object underneath the
+ * Embedded Controller device."
+ *
+ * To quickly access the EC device, we use the EC_ID that appears
+ * within the ECDT. Otherwise, we would need to perform a time-
+ * consuming namespace walk, executing _HID methods to find the
+ * EC device.
+ *
+ ******************************************************************************/
+
+static void acpi_ev_orphan_ec_reg_method(void)
+{
+ struct acpi_table_ecdt *table;
+ acpi_status status;
+ struct acpi_object_list args;
+ union acpi_object objects[2];
+ struct acpi_namespace_node *ec_device_node;
+ struct acpi_namespace_node *reg_method;
+ struct acpi_namespace_node *next_node;
+
+ ACPI_FUNCTION_TRACE(ev_orphan_ec_reg_method);
+
+ /* Get the ECDT (if present in system) */
+
+ status = acpi_get_table(ACPI_SIG_ECDT, 0,
+ ACPI_CAST_INDIRECT_PTR(struct acpi_table_header,
+ &table));
+ if (ACPI_FAILURE(status)) {
+ return_VOID;
+ }
+
+ /* We need a valid EC_ID string */
+
+ if (!(*table->id)) {
+ return_VOID;
+ }
+
+ /* Namespace is currently locked, must release */
+
+ (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+
+ /* Get a handle to the EC device referenced in the ECDT */
+
+ status = acpi_get_handle(NULL,
+ ACPI_CAST_PTR(char, table->id),
+ ACPI_CAST_PTR(acpi_handle, &ec_device_node));
+ if (ACPI_FAILURE(status)) {
+ goto exit;
+ }
+
+ /* Get a handle to a _REG method immediately under the EC device */
+
+ status = acpi_get_handle(ec_device_node,
+ METHOD_NAME__REG, ACPI_CAST_PTR(acpi_handle,
+ &reg_method));
+ if (ACPI_FAILURE(status)) {
+ goto exit;
+ }
+
+ /*
+ * Execute the _REG method only if there is no Operation Region in
+ * this scope with the Embedded Controller space ID. Otherwise, it
+ * will already have been executed. Note, this allows for Regions
+ * with other space IDs to be present; but the code below will then
+ * execute the _REG method with the EC space ID argument.
+ */
+ next_node = acpi_ns_get_next_node(ec_device_node, NULL);
+ while (next_node) {
+ if ((next_node->type == ACPI_TYPE_REGION) &&
+ (next_node->object) &&
+ (next_node->object->region.space_id == ACPI_ADR_SPACE_EC)) {
+ goto exit; /* Do not execute _REG */
+ }
+ next_node = acpi_ns_get_next_node(ec_device_node, next_node);
+ }
+
+ /* Evaluate the _REG(EC,Connect) method */
+
+ args.count = 2;
+ args.pointer = objects;
+ objects[0].type = ACPI_TYPE_INTEGER;
+ objects[0].integer.value = ACPI_ADR_SPACE_EC;
+ objects[1].type = ACPI_TYPE_INTEGER;
+ objects[1].integer.value = ACPI_REG_CONNECT;
+
+ status = acpi_evaluate_object(reg_method, NULL, &args, NULL);
+
+ exit:
+ /* We ignore all errors from above, don't care */
+
+ status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
+ return_VOID;
+}