NFC: Add firmware upload netlink command

As several NFC chipsets can have their firmwares upgraded and
reflashed, this patchset adds a new netlink command to trigger
that the driver loads or flashes a new firmware. This will allows
userspace triggered firmware upgrade through netlink.
The firmware name or hint is passed as a parameter, and the driver
will eventually fetch the firmware binary through the request_firmware
API.
The cmd can only be executed when the nfc dev is not in use. Actual
firmware loading/flashing is an asynchronous operation. Result of the
operation shall send a new event up to user space through the nfc dev
multicast socket. During operation, the nfc dev is not openable and
thus not usable.

Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

include/uapi/linux/nfc.h

@@ -69,6 +69,8 @@
  *	starting a poll from a device which has a secure element enabled means
  *	we want to do SE based card emulation.
  * @NFC_CMD_DISABLE_SE: Disable the physical link to a specific secure element.
+ * @NFC_CMD_FW_UPLOAD: Request to Load/flash firmware, or event to inform that
+ *	some firmware was loaded
  */
 enum nfc_commands {
 	NFC_CMD_UNSPEC,
@@ -92,6 +94,7 @@ enum nfc_commands {
 	NFC_CMD_DISABLE_SE,
 	NFC_CMD_LLC_SDREQ,
 	NFC_EVENT_LLC_SDRES,
+	NFC_CMD_FW_UPLOAD,
 /* private: internal use only */
 	__NFC_CMD_AFTER_LAST
 };
@@ -121,6 +124,7 @@ enum nfc_commands {
  * @NFC_ATTR_LLC_PARAM_RW: Receive Window size parameter
  * @NFC_ATTR_LLC_PARAM_MIUX: MIU eXtension parameter
  * @NFC_ATTR_SE: Available Secure Elements
+ * @NFC_ATTR_FIRMWARE_NAME: Free format firmware version
  */
 enum nfc_attrs {
 	NFC_ATTR_UNSPEC,
@@ -143,6 +147,7 @@ enum nfc_attrs {
 	NFC_ATTR_LLC_PARAM_MIUX,
 	NFC_ATTR_SE,
 	NFC_ATTR_LLC_SDP,
+	NFC_ATTR_FIRMWARE_NAME,
 /* private: internal use only */
 	__NFC_ATTR_AFTER_LAST
 };
@@ -162,6 +167,7 @@ enum nfc_sdp_attr {
 #define NFC_SENSB_RES_MAXSIZE 12
 #define NFC_SENSF_RES_MAXSIZE 18
 #define NFC_GB_MAXSIZE        48
+#define NFC_FIRMWARE_NAME_MAXSIZE 32
 
 /* NFC protocols */
 #define NFC_PROTO_JEWEL		1