iwlwifi: acpi: add common code to read from ACPI

There are many places where the same process of invoking a method from
ACPI is used, causing a lot of duplicate code.  To improve this,
introduce a new function to get an ACPI object by invoking an ACPI
method that can be reused.

Additionally, since this function needs to be called when we only have
the trans, the opmode or the device, introduce a new debug macro that
gets the device as a parameter so it can be used in the new function.

Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

1 files changed, 97 insertions, 0 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/fw/acpi.c b/drivers/net/wireless/intel/iwlwifi/fw/acpi.c
new file mode 100644
index 000000000000..a7b2a48618cd
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/fw/acpi.c
@@ -0,0 +1,97 @@
+/******************************************************************************
+ *
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2017        Intel Deutschland GmbH
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program;
+ *
+ * The full GNU General Public License is included in this distribution
+ * in the file called COPYING.
+ *
+ * Contact Information:
+ *  Intel Linux Wireless <linuxwifi@intel.com>
+ * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
+ *
+ * BSD LICENSE
+ *
+ * Copyright(c) 2017        Intel Deutschland GmbH
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *  * Neither the name Intel Corporation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ *****************************************************************************/
+
+#include "iwl-drv.h"
+#include "iwl-debug.h"
+#include "acpi.h"
+
+void *iwl_acpi_get_object(struct device *dev, acpi_string method)
+{
+	acpi_handle root_handle;
+	acpi_handle handle;
+	struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
+	acpi_status status;
+
+	root_handle = ACPI_HANDLE(dev);
+	if (!root_handle) {
+		IWL_DEBUG_DEV_RADIO(dev,
+				    "Could not retrieve root port ACPI handle\n");
+		return ERR_PTR(-ENOENT);
+	}
+
+	/* Get the method's handle */
+	status = acpi_get_handle(root_handle, method, &handle);
+	if (ACPI_FAILURE(status)) {
+		IWL_DEBUG_DEV_RADIO(dev, "%s method not found\n", method);
+		return ERR_PTR(-ENOENT);
+	}
+
+	/* Call the method with no arguments */
+	status = acpi_evaluate_object(handle, NULL, NULL, &buf);
+	if (ACPI_FAILURE(status)) {
+		IWL_DEBUG_DEV_RADIO(dev, "%s invocation failed (0x%x)\n",
+				    method, status);
+		return ERR_PTR(-ENOENT);
+	}
+
+	return buf.pointer;
+}
+IWL_EXPORT_SYMBOL(iwl_acpi_get_object);