iwlwifi: move BIOS MCC retrieval to common code

This will be used by more than MVM, so move it to iwlwifi

While at it, rename WRD_METHOD to the more appropriate
WRDD_METHOD and add some documentation.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

1 files changed, 89 insertions, 0 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c b/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c
index adba3b003f55..3bd6fc1b76d4 100644
--- a/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c
@@ -67,6 +67,7 @@
 #include <linux/export.h>
 #include <linux/etherdevice.h>
 #include <linux/pci.h>
+#include <linux/acpi.h>
 #include "iwl-drv.h"
 #include "iwl-modparams.h"
 #include "iwl-nvm-parse.h"
@@ -904,3 +905,91 @@ iwl_parse_nvm_mcc_info(struct device *dev, const struct iwl_cfg *cfg,
 	return regd;
 }
 IWL_EXPORT_SYMBOL(iwl_parse_nvm_mcc_info);
+
+#ifdef CONFIG_ACPI
+#define WRDD_METHOD		"WRDD"
+#define WRDD_WIFI		(0x07)
+#define WRDD_WIGIG		(0x10)
+
+static u32 iwl_wrdd_get_mcc(struct device *dev, union acpi_object *wrdd)
+{
+	union acpi_object *mcc_pkg, *domain_type, *mcc_value;
+	u32 i;
+
+	if (wrdd->type != ACPI_TYPE_PACKAGE ||
+	    wrdd->package.count < 2 ||
+	    wrdd->package.elements[0].type != ACPI_TYPE_INTEGER ||
+	    wrdd->package.elements[0].integer.value != 0) {
+		IWL_DEBUG_EEPROM(dev, "Unsupported wrdd structure\n");
+		return 0;
+	}
+
+	for (i = 1 ; i < wrdd->package.count ; ++i) {
+		mcc_pkg = &wrdd->package.elements[i];
+
+		if (mcc_pkg->type != ACPI_TYPE_PACKAGE ||
+		    mcc_pkg->package.count < 2 ||
+		    mcc_pkg->package.elements[0].type != ACPI_TYPE_INTEGER ||
+		    mcc_pkg->package.elements[1].type != ACPI_TYPE_INTEGER) {
+			mcc_pkg = NULL;
+			continue;
+		}
+
+		domain_type = &mcc_pkg->package.elements[0];
+		if (domain_type->integer.value == WRDD_WIFI)
+			break;
+
+		mcc_pkg = NULL;
+	}
+
+	if (mcc_pkg) {
+		mcc_value = &mcc_pkg->package.elements[1];
+		return mcc_value->integer.value;
+	}
+
+	return 0;
+}
+
+int iwl_get_bios_mcc(struct device *dev, char *mcc)
+{
+	acpi_handle root_handle;
+	acpi_handle handle;
+	struct acpi_buffer wrdd = {ACPI_ALLOCATE_BUFFER, NULL};
+	acpi_status status;
+	u32 mcc_val;
+
+	root_handle = ACPI_HANDLE(dev);
+	if (!root_handle) {
+		IWL_DEBUG_EEPROM(dev,
+				 "Could not retrieve root port ACPI handle\n");
+		return -ENOENT;
+	}
+
+	/* Get the method's handle */
+	status = acpi_get_handle(root_handle, (acpi_string)WRDD_METHOD,
+				 &handle);
+	if (ACPI_FAILURE(status)) {
+		IWL_DEBUG_EEPROM(dev, "WRD method not found\n");
+		return -ENOENT;
+	}
+
+	/* Call WRDD with no arguments */
+	status = acpi_evaluate_object(handle, NULL, NULL, &wrdd);
+	if (ACPI_FAILURE(status)) {
+		IWL_DEBUG_EEPROM(dev, "WRDC invocation failed (0x%x)\n",
+				 status);
+		return -ENOENT;
+	}
+
+	mcc_val = iwl_wrdd_get_mcc(dev, wrdd.pointer);
+	kfree(wrdd.pointer);
+	if (!mcc_val)
+		return -ENOENT;
+
+	mcc[0] = (mcc_val >> 8) & 0xff;
+	mcc[1] = mcc_val & 0xff;
+	mcc[2] = '\0';
+	return 0;
+}
+IWL_EXPORT_SYMBOL(iwl_get_bios_mcc);
+#endif