iwlwifi: rely on API version read from firmware

This adds the infrastructure to support older firmware APIs.
The API version number is stored as part of the filename, we first try to
load the most recent firmware and progressively try lower versions.
The API version is also read from the firmware self and stored as part
of the iwl_priv structure. Only firmware that is supported by driver will
be loaded. The version number read from firmware is compared
to supported versions in the driver not the API version used as part of
filename.

An example using this new infrastrucure:
   if (IWL_UCODE_API(priv->ucode_ver) >= 2) {
        Driver interacts with Firmware API version >= 2.
   } else {
        Driver interacts with Firmware API version 1.
   }

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 9 insertions, 5 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-3945.h b/drivers/net/wireless/iwlwifi/iwl-3945.h
index 972c4542e5bc..d6502b426a06 100644
--- a/drivers/net/wireless/iwlwifi/iwl-3945.h
+++ b/drivers/net/wireless/iwlwifi/iwl-3945.h
@@ -50,11 +50,15 @@ extern struct pci_device_id iwl3945_hw_card_ids[];
 #include "iwl-3945-debug.h"
 #include "iwl-3945-led.h"
 
-/* Change firmware file name, using "-" and incrementing number,
- *   *only* when uCode interface or architecture changes so that it
- *   is not compatible with earlier drivers.
- * This number will also appear in << 8 position of 1st dword of uCode file */
-#define IWL3945_UCODE_API "-1"
+/* Highest firmware API version supported */
+#define IWL3945_UCODE_API_MAX 1
+
+/* Lowest firmware API version supported */
+#define IWL3945_UCODE_API_MIN 1
+
+#define IWL3945_FW_PRE  "iwlwifi-3945-"
+#define _IWL3945_MODULE_FIRMWARE(api) IWL3945_FW_PRE #api ".ucode"
+#define IWL3945_MODULE_FIRMWARE(api) _IWL3945_MODULE_FIRMWARE(api)
 
 /* Default noise level to report when noise measurement is not available.
  *   This may be because we're: