wl12xx: add driver

wl12xx is a driver for TI wl1251 802.11 chipset designed for embedded
devices, supporting both SDIO and SPI busses. Currently the driver
supports only SPI. Adding support 1253 (the 5 GHz version) should be
relatively easy. More information here:

http://focus.ti.com/general/docs/wtbu/wtbuproductcontent.tsp?contentId=4711&navigationId=12494&templateId=6123

(Collapsed original sequence of pre-merge patches into single commit for
initial merge. -- JWL)

Signed-off-by: Kalle Valo <kalle.valo@nokia.com>
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/wl12xx/rx.h b/drivers/net/wireless/wl12xx/rx.h
new file mode 100644
index 0000000..8a23fde
--- /dev/null
+++ b/drivers/net/wireless/wl12xx/rx.h
@@ -0,0 +1,122 @@
+/*
+ * This file is part of wl12xx
+ *
+ * Copyright (c) 1998-2007 Texas Instruments Incorporated
+ * Copyright (C) 2008 Nokia Corporation
+ *
+ * Contact: Kalle Valo <kalle.valo@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 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; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#ifndef __WL12XX_RX_H__
+#define __WL12XX_RX_H__
+
+#include <linux/bitops.h>
+
+/*
+ * RX PATH
+ *
+ * The Rx path uses a double buffer and an rx_contro structure, each located
+ * at a fixed address in the device memory. The host keeps track of which
+ * buffer is available and alternates between them on a per packet basis.
+ * The size of each of the two buffers is large enough to hold the longest
+ * 802.3 packet.
+ * The RX path goes like that:
+ * 1) The target generates an interrupt each time a new packet is received.
+ *   There are 2 RX interrupts, one for each buffer.
+ * 2) The host reads the received packet from one of the double buffers.
+ * 3) The host triggers a target interrupt.
+ * 4) The target prepares the next RX packet.
+ */
+
+#define WL12XX_RX_MAX_RSSI -30
+#define WL12XX_RX_MIN_RSSI -95
+
+#define WL12XX_RX_ALIGN_TO 4
+#define WL12XX_RX_ALIGN(len) (((len) + WL12XX_RX_ALIGN_TO - 1) & \
+			     ~(WL12XX_RX_ALIGN_TO - 1))
+
+#define SHORT_PREAMBLE_BIT   BIT(0)
+#define OFDM_RATE_BIT        BIT(6)
+#define PBCC_RATE_BIT        BIT(7)
+
+#define PLCP_HEADER_LENGTH 8
+#define RX_DESC_PACKETID_SHIFT 11
+#define RX_MAX_PACKET_ID 3
+
+#define RX_DESC_VALID_FCS         0x0001
+#define RX_DESC_MATCH_RXADDR1     0x0002
+#define RX_DESC_MCAST             0x0004
+#define RX_DESC_STAINTIM          0x0008
+#define RX_DESC_VIRTUAL_BM        0x0010
+#define RX_DESC_BCAST             0x0020
+#define RX_DESC_MATCH_SSID        0x0040
+#define RX_DESC_MATCH_BSSID       0x0080
+#define RX_DESC_ENCRYPTION_MASK   0x0300
+#define RX_DESC_MEASURMENT        0x0400
+#define RX_DESC_SEQNUM_MASK       0x1800
+#define	RX_DESC_MIC_FAIL	  0x2000
+#define	RX_DESC_DECRYPT_FAIL	  0x4000
+
+struct wl12xx_rx_descriptor {
+	u32 timestamp; /* In microseconds */
+	u16 length; /* Paylod length, including headers */
+	u16 flags;
+
+	/*
+	 * 0 - 802.11
+	 * 1 - 802.3
+	 * 2 - IP
+	 * 3 - Raw Codec
+	 */
+	u8 type;
+
+	/*
+	 * Recevied Rate:
+	 * 0x0A - 1MBPS
+	 * 0x14 - 2MBPS
+	 * 0x37 - 5_5MBPS
+	 * 0x0B - 6MBPS
+	 * 0x0F - 9MBPS
+	 * 0x6E - 11MBPS
+	 * 0x0A - 12MBPS
+	 * 0x0E - 18MBPS
+	 * 0xDC - 22MBPS
+	 * 0x09 - 24MBPS
+	 * 0x0D - 36MBPS
+	 * 0x08 - 48MBPS
+	 * 0x0C - 54MBPS
+	 */
+	u8 rate;
+
+	u8 mod_pre; /* Modulation and preamble */
+	u8 channel;
+
+	/*
+	 * 0 - 2.4 Ghz
+	 * 1 - 5 Ghz
+	 */
+	u8 band;
+
+	s8 rssi; /* in dB */
+	u8 rcpi; /* in dB */
+	u8 snr; /* in dB */
+} __attribute__ ((packed));
+
+void wl12xx_rx(struct wl12xx *wl);
+
+#endif