Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 786 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath5k/desc.c b/drivers/net/wireless/ath/ath5k/desc.c
new file mode 100644
index 000000000..80f751394
--- /dev/null
+++ b/drivers/net/wireless/ath/ath5k/desc.c
@@ -0,0 +1,786 @@
+/*
+ * Copyright (c) 2004-2008 Reyk Floeter <reyk@openbsd.org>
+ * Copyright (c) 2006-2008 Nick Kossifidis <mickflemm@gmail.com>
+ * Copyright (c) 2007-2008 Pavel Roskin <proski@gnu.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+/******************************\
+ Hardware Descriptor Functions
+\******************************/
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include "ath5k.h"
+#include "reg.h"
+#include "debug.h"
+
+
+/**
+ * DOC: Hardware descriptor functions
+ *
+ * Here we handle the processing of the low-level hw descriptors
+ * that hw reads and writes via DMA for each TX and RX attempt (that means
+ * we can also have descriptors for failed TX/RX tries). We have two kind of
+ * descriptors for RX and TX, control descriptors tell the hw how to send or
+ * receive a packet where to read/write it from/to etc and status descriptors
+ * that contain information about how the packet was sent or received (errors
+ * included).
+ *
+ * Descriptor format is not exactly the same for each MAC chip version so we
+ * have function pointers on &struct ath5k_hw we initialize at runtime based on
+ * the chip used.
+ */
+
+
+/************************\
+* TX Control descriptors *
+\************************/
+
+/**
+ * ath5k_hw_setup_2word_tx_desc() - Initialize a 2-word tx control descriptor
+ * @ah: The &struct ath5k_hw
+ * @desc: The &struct ath5k_desc
+ * @pkt_len: Frame length in bytes
+ * @hdr_len: Header length in bytes (only used on AR5210)
+ * @padsize: Any padding we've added to the frame length
+ * @type: One of enum ath5k_pkt_type
+ * @tx_power: Tx power in 0.5dB steps
+ * @tx_rate0: HW idx for transmission rate
+ * @tx_tries0: Max number of retransmissions
+ * @key_index: Index on key table to use for encryption
+ * @antenna_mode: Which antenna to use (0 for auto)
+ * @flags: One of AR5K_TXDESC_* flags (desc.h)
+ * @rtscts_rate: HW idx for RTS/CTS transmission rate
+ * @rtscts_duration: What to put on duration field on the header of RTS/CTS
+ *
+ * Internal function to initialize a 2-Word TX control descriptor
+ * found on AR5210 and AR5211 MACs chips.
+ *
+ * Returns 0 on success or -EINVAL on false input
+ */
+static int
+ath5k_hw_setup_2word_tx_desc(struct ath5k_hw *ah,
+			struct ath5k_desc *desc,
+			unsigned int pkt_len, unsigned int hdr_len,
+			int padsize,
+			enum ath5k_pkt_type type,
+			unsigned int tx_power,
+			unsigned int tx_rate0, unsigned int tx_tries0,
+			unsigned int key_index,
+			unsigned int antenna_mode,
+			unsigned int flags,
+			unsigned int rtscts_rate, unsigned int rtscts_duration)
+{
+	u32 frame_type;
+	struct ath5k_hw_2w_tx_ctl *tx_ctl;
+	unsigned int frame_len;
+
+	tx_ctl = &desc->ud.ds_tx5210.tx_ctl;
+
+	/*
+	 * Validate input
+	 * - Zero retries don't make sense.
+	 * - A zero rate will put the HW into a mode where it continuously sends
+	 *   noise on the channel, so it is important to avoid this.
+	 */
+	if (unlikely(tx_tries0 == 0)) {
+		ATH5K_ERR(ah, "zero retries\n");
+		WARN_ON(1);
+		return -EINVAL;
+	}
+	if (unlikely(tx_rate0 == 0)) {
+		ATH5K_ERR(ah, "zero rate\n");
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	/* Clear descriptor */
+	memset(&desc->ud.ds_tx5210, 0, sizeof(struct ath5k_hw_5210_tx_desc));
+
+	/* Setup control descriptor */
+
+	/* Verify and set frame length */
+
+	/* remove padding we might have added before */
+	frame_len = pkt_len - padsize + FCS_LEN;
+
+	if (frame_len & ~AR5K_2W_TX_DESC_CTL0_FRAME_LEN)
+		return -EINVAL;
+
+	tx_ctl->tx_control_0 = frame_len & AR5K_2W_TX_DESC_CTL0_FRAME_LEN;
+
+	/* Verify and set buffer length */
+
+	/* NB: beacon's BufLen must be a multiple of 4 bytes */
+	if (type == AR5K_PKT_TYPE_BEACON)
+		pkt_len = roundup(pkt_len, 4);
+
+	if (pkt_len & ~AR5K_2W_TX_DESC_CTL1_BUF_LEN)
+		return -EINVAL;
+
+	tx_ctl->tx_control_1 = pkt_len & AR5K_2W_TX_DESC_CTL1_BUF_LEN;
+
+	/*
+	 * Verify and set header length (only 5210)
+	 */
+	if (ah->ah_version == AR5K_AR5210) {
+		if (hdr_len & ~AR5K_2W_TX_DESC_CTL0_HEADER_LEN_5210)
+			return -EINVAL;
+		tx_ctl->tx_control_0 |=
+			AR5K_REG_SM(hdr_len, AR5K_2W_TX_DESC_CTL0_HEADER_LEN_5210);
+	}
+
+	/*Differences between 5210-5211*/
+	if (ah->ah_version == AR5K_AR5210) {
+		switch (type) {
+		case AR5K_PKT_TYPE_BEACON:
+		case AR5K_PKT_TYPE_PROBE_RESP:
+			frame_type = AR5K_AR5210_TX_DESC_FRAME_TYPE_NO_DELAY;
+			break;
+		case AR5K_PKT_TYPE_PIFS:
+			frame_type = AR5K_AR5210_TX_DESC_FRAME_TYPE_PIFS;
+			break;
+		default:
+			frame_type = type;
+			break;
+		}
+
+		tx_ctl->tx_control_0 |=
+		AR5K_REG_SM(frame_type, AR5K_2W_TX_DESC_CTL0_FRAME_TYPE_5210) |
+		AR5K_REG_SM(tx_rate0, AR5K_2W_TX_DESC_CTL0_XMIT_RATE);
+
+	} else {
+		tx_ctl->tx_control_0 |=
+			AR5K_REG_SM(tx_rate0, AR5K_2W_TX_DESC_CTL0_XMIT_RATE) |
+			AR5K_REG_SM(antenna_mode,
+				AR5K_2W_TX_DESC_CTL0_ANT_MODE_XMIT);
+		tx_ctl->tx_control_1 |=
+			AR5K_REG_SM(type, AR5K_2W_TX_DESC_CTL1_FRAME_TYPE_5211);
+	}
+
+#define _TX_FLAGS(_c, _flag)					\
+	if (flags & AR5K_TXDESC_##_flag) {			\
+		tx_ctl->tx_control_##_c |=			\
+			AR5K_2W_TX_DESC_CTL##_c##_##_flag;	\
+	}
+#define _TX_FLAGS_5211(_c, _flag)					\
+	if (flags & AR5K_TXDESC_##_flag) {				\
+		tx_ctl->tx_control_##_c |=				\
+			AR5K_2W_TX_DESC_CTL##_c##_##_flag##_5211;	\
+	}
+	_TX_FLAGS(0, CLRDMASK);
+	_TX_FLAGS(0, INTREQ);
+	_TX_FLAGS(0, RTSENA);
+
+	if (ah->ah_version == AR5K_AR5211) {
+		_TX_FLAGS_5211(0, VEOL);
+		_TX_FLAGS_5211(1, NOACK);
+	}
+
+#undef _TX_FLAGS
+#undef _TX_FLAGS_5211
+
+	/*
+	 * WEP crap
+	 */
+	if (key_index != AR5K_TXKEYIX_INVALID) {
+		tx_ctl->tx_control_0 |=
+			AR5K_2W_TX_DESC_CTL0_ENCRYPT_KEY_VALID;
+		tx_ctl->tx_control_1 |=
+			AR5K_REG_SM(key_index,
+			AR5K_2W_TX_DESC_CTL1_ENC_KEY_IDX);
+	}
+
+	/*
+	 * RTS/CTS Duration [5210 ?]
+	 */
+	if ((ah->ah_version == AR5K_AR5210) &&
+			(flags & (AR5K_TXDESC_RTSENA | AR5K_TXDESC_CTSENA)))
+		tx_ctl->tx_control_1 |= rtscts_duration &
+				AR5K_2W_TX_DESC_CTL1_RTS_DURATION_5210;
+
+	return 0;
+}
+
+/**
+ * ath5k_hw_setup_4word_tx_desc() - Initialize a 4-word tx control descriptor
+ * @ah: The &struct ath5k_hw
+ * @desc: The &struct ath5k_desc
+ * @pkt_len: Frame length in bytes
+ * @hdr_len: Header length in bytes (only used on AR5210)
+ * @padsize: Any padding we've added to the frame length
+ * @type: One of enum ath5k_pkt_type
+ * @tx_power: Tx power in 0.5dB steps
+ * @tx_rate0: HW idx for transmission rate
+ * @tx_tries0: Max number of retransmissions
+ * @key_index: Index on key table to use for encryption
+ * @antenna_mode: Which antenna to use (0 for auto)
+ * @flags: One of AR5K_TXDESC_* flags (desc.h)
+ * @rtscts_rate: HW idx for RTS/CTS transmission rate
+ * @rtscts_duration: What to put on duration field on the header of RTS/CTS
+ *
+ * Internal function to initialize a 4-Word TX control descriptor
+ * found on AR5212 and later MACs chips.
+ *
+ * Returns 0 on success or -EINVAL on false input
+ */
+static int
+ath5k_hw_setup_4word_tx_desc(struct ath5k_hw *ah,
+			struct ath5k_desc *desc,
+			unsigned int pkt_len, unsigned int hdr_len,
+			int padsize,
+			enum ath5k_pkt_type type,
+			unsigned int tx_power,
+			unsigned int tx_rate0, unsigned int tx_tries0,
+			unsigned int key_index,
+			unsigned int antenna_mode,
+			unsigned int flags,
+			unsigned int rtscts_rate, unsigned int rtscts_duration)
+{
+	struct ath5k_hw_4w_tx_ctl *tx_ctl;
+	unsigned int frame_len;
+
+	/*
+	 * Use local variables for these to reduce load/store access on
+	 * uncached memory
+	 */
+	u32 txctl0 = 0, txctl1 = 0, txctl2 = 0, txctl3 = 0;
+
+	tx_ctl = &desc->ud.ds_tx5212.tx_ctl;
+
+	/*
+	 * Validate input
+	 * - Zero retries don't make sense.
+	 * - A zero rate will put the HW into a mode where it continuously sends
+	 *   noise on the channel, so it is important to avoid this.
+	 */
+	if (unlikely(tx_tries0 == 0)) {
+		ATH5K_ERR(ah, "zero retries\n");
+		WARN_ON(1);
+		return -EINVAL;
+	}
+	if (unlikely(tx_rate0 == 0)) {
+		ATH5K_ERR(ah, "zero rate\n");
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	tx_power += ah->ah_txpower.txp_offset;
+	if (tx_power > AR5K_TUNE_MAX_TXPOWER)
+		tx_power = AR5K_TUNE_MAX_TXPOWER;
+
+	/* Clear descriptor status area */
+	memset(&desc->ud.ds_tx5212.tx_stat, 0,
+	       sizeof(desc->ud.ds_tx5212.tx_stat));
+
+	/* Setup control descriptor */
+
+	/* Verify and set frame length */
+
+	/* remove padding we might have added before */
+	frame_len = pkt_len - padsize + FCS_LEN;
+
+	if (frame_len & ~AR5K_4W_TX_DESC_CTL0_FRAME_LEN)
+		return -EINVAL;
+
+	txctl0 = frame_len & AR5K_4W_TX_DESC_CTL0_FRAME_LEN;
+
+	/* Verify and set buffer length */
+
+	/* NB: beacon's BufLen must be a multiple of 4 bytes */
+	if (type == AR5K_PKT_TYPE_BEACON)
+		pkt_len = roundup(pkt_len, 4);
+
+	if (pkt_len & ~AR5K_4W_TX_DESC_CTL1_BUF_LEN)
+		return -EINVAL;
+
+	txctl1 = pkt_len & AR5K_4W_TX_DESC_CTL1_BUF_LEN;
+
+	txctl0 |= AR5K_REG_SM(tx_power, AR5K_4W_TX_DESC_CTL0_XMIT_POWER) |
+		  AR5K_REG_SM(antenna_mode, AR5K_4W_TX_DESC_CTL0_ANT_MODE_XMIT);
+	txctl1 |= AR5K_REG_SM(type, AR5K_4W_TX_DESC_CTL1_FRAME_TYPE);
+	txctl2 = AR5K_REG_SM(tx_tries0, AR5K_4W_TX_DESC_CTL2_XMIT_TRIES0);
+	txctl3 = tx_rate0 & AR5K_4W_TX_DESC_CTL3_XMIT_RATE0;
+
+#define _TX_FLAGS(_c, _flag)					\
+	if (flags & AR5K_TXDESC_##_flag) {			\
+		txctl##_c |= AR5K_4W_TX_DESC_CTL##_c##_##_flag;	\
+	}
+
+	_TX_FLAGS(0, CLRDMASK);
+	_TX_FLAGS(0, VEOL);
+	_TX_FLAGS(0, INTREQ);
+	_TX_FLAGS(0, RTSENA);
+	_TX_FLAGS(0, CTSENA);
+	_TX_FLAGS(1, NOACK);
+
+#undef _TX_FLAGS
+
+	/*
+	 * WEP crap
+	 */
+	if (key_index != AR5K_TXKEYIX_INVALID) {
+		txctl0 |= AR5K_4W_TX_DESC_CTL0_ENCRYPT_KEY_VALID;
+		txctl1 |= AR5K_REG_SM(key_index,
+				AR5K_4W_TX_DESC_CTL1_ENCRYPT_KEY_IDX);
+	}
+
+	/*
+	 * RTS/CTS
+	 */
+	if (flags & (AR5K_TXDESC_RTSENA | AR5K_TXDESC_CTSENA)) {
+		if ((flags & AR5K_TXDESC_RTSENA) &&
+				(flags & AR5K_TXDESC_CTSENA))
+			return -EINVAL;
+		txctl2 |= rtscts_duration & AR5K_4W_TX_DESC_CTL2_RTS_DURATION;
+		txctl3 |= AR5K_REG_SM(rtscts_rate,
+				AR5K_4W_TX_DESC_CTL3_RTS_CTS_RATE);
+	}
+
+	tx_ctl->tx_control_0 = txctl0;
+	tx_ctl->tx_control_1 = txctl1;
+	tx_ctl->tx_control_2 = txctl2;
+	tx_ctl->tx_control_3 = txctl3;
+
+	return 0;
+}
+
+/**
+ * ath5k_hw_setup_mrr_tx_desc() - Initialize an MRR tx control descriptor
+ * @ah: The &struct ath5k_hw
+ * @desc: The &struct ath5k_desc
+ * @tx_rate1: HW idx for rate used on transmission series 1
+ * @tx_tries1: Max number of retransmissions for transmission series 1
+ * @tx_rate2: HW idx for rate used on transmission series 2
+ * @tx_tries2: Max number of retransmissions for transmission series 2
+ * @tx_rate3: HW idx for rate used on transmission series 3
+ * @tx_tries3: Max number of retransmissions for transmission series 3
+ *
+ * Multi rate retry (MRR) tx control descriptors are available only on AR5212
+ * MACs, they are part of the normal 4-word tx control descriptor (see above)
+ * but we handle them through a separate function for better abstraction.
+ *
+ * Returns 0 on success or -EINVAL on invalid input
+ */
+int
+ath5k_hw_setup_mrr_tx_desc(struct ath5k_hw *ah,
+			struct ath5k_desc *desc,
+			u_int tx_rate1, u_int tx_tries1,
+			u_int tx_rate2, u_int tx_tries2,
+			u_int tx_rate3, u_int tx_tries3)
+{
+	struct ath5k_hw_4w_tx_ctl *tx_ctl;
+
+	/* no mrr support for cards older than 5212 */
+	if (ah->ah_version < AR5K_AR5212)
+		return 0;
+
+	/*
+	 * Rates can be 0 as long as the retry count is 0 too.
+	 * A zero rate and nonzero retry count will put the HW into a mode where
+	 * it continuously sends noise on the channel, so it is important to
+	 * avoid this.
+	 */
+	if (unlikely((tx_rate1 == 0 && tx_tries1 != 0) ||
+		     (tx_rate2 == 0 && tx_tries2 != 0) ||
+		     (tx_rate3 == 0 && tx_tries3 != 0))) {
+		ATH5K_ERR(ah, "zero rate\n");
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	if (ah->ah_version == AR5K_AR5212) {
+		tx_ctl = &desc->ud.ds_tx5212.tx_ctl;
+
+#define _XTX_TRIES(_n)							\
+	if (tx_tries##_n) {						\
+		tx_ctl->tx_control_2 |=					\
+		    AR5K_REG_SM(tx_tries##_n,				\
+		    AR5K_4W_TX_DESC_CTL2_XMIT_TRIES##_n);		\
+		tx_ctl->tx_control_3 |=					\
+		    AR5K_REG_SM(tx_rate##_n,				\
+		    AR5K_4W_TX_DESC_CTL3_XMIT_RATE##_n);		\
+	}
+
+		_XTX_TRIES(1);
+		_XTX_TRIES(2);
+		_XTX_TRIES(3);
+
+#undef _XTX_TRIES
+
+		return 1;
+	}
+
+	return 0;
+}
+
+
+/***********************\
+* TX Status descriptors *
+\***********************/
+
+/**
+ * ath5k_hw_proc_2word_tx_status() - Process a tx status descriptor on 5210/1
+ * @ah: The &struct ath5k_hw
+ * @desc: The &struct ath5k_desc
+ * @ts: The &struct ath5k_tx_status
+ */
+static int
+ath5k_hw_proc_2word_tx_status(struct ath5k_hw *ah,
+				struct ath5k_desc *desc,
+				struct ath5k_tx_status *ts)
+{
+	struct ath5k_hw_tx_status *tx_status;
+
+	tx_status = &desc->ud.ds_tx5210.tx_stat;
+
+	/* No frame has been send or error */
+	if (unlikely((tx_status->tx_status_1 & AR5K_DESC_TX_STATUS1_DONE) == 0))
+		return -EINPROGRESS;
+
+	/*
+	 * Get descriptor status
+	 */
+	ts->ts_tstamp = AR5K_REG_MS(tx_status->tx_status_0,
+		AR5K_DESC_TX_STATUS0_SEND_TIMESTAMP);
+	ts->ts_shortretry = AR5K_REG_MS(tx_status->tx_status_0,
+		AR5K_DESC_TX_STATUS0_SHORT_RETRY_COUNT);
+	ts->ts_final_retry = AR5K_REG_MS(tx_status->tx_status_0,
+		AR5K_DESC_TX_STATUS0_LONG_RETRY_COUNT);
+	/*TODO: ts->ts_virtcol + test*/
+	ts->ts_seqnum = AR5K_REG_MS(tx_status->tx_status_1,
+		AR5K_DESC_TX_STATUS1_SEQ_NUM);
+	ts->ts_rssi = AR5K_REG_MS(tx_status->tx_status_1,
+		AR5K_DESC_TX_STATUS1_ACK_SIG_STRENGTH);
+	ts->ts_antenna = 1;
+	ts->ts_status = 0;
+	ts->ts_final_idx = 0;
+
+	if (!(tx_status->tx_status_0 & AR5K_DESC_TX_STATUS0_FRAME_XMIT_OK)) {
+		if (tx_status->tx_status_0 &
+				AR5K_DESC_TX_STATUS0_EXCESSIVE_RETRIES)
+			ts->ts_status |= AR5K_TXERR_XRETRY;
+
+		if (tx_status->tx_status_0 & AR5K_DESC_TX_STATUS0_FIFO_UNDERRUN)
+			ts->ts_status |= AR5K_TXERR_FIFO;
+
+		if (tx_status->tx_status_0 & AR5K_DESC_TX_STATUS0_FILTERED)
+			ts->ts_status |= AR5K_TXERR_FILT;
+	}
+
+	return 0;
+}
+
+/**
+ * ath5k_hw_proc_4word_tx_status() - Process a tx status descriptor on 5212
+ * @ah: The &struct ath5k_hw
+ * @desc: The &struct ath5k_desc
+ * @ts: The &struct ath5k_tx_status
+ */
+static int
+ath5k_hw_proc_4word_tx_status(struct ath5k_hw *ah,
+				struct ath5k_desc *desc,
+				struct ath5k_tx_status *ts)
+{
+	struct ath5k_hw_tx_status *tx_status;
+	u32 txstat0, txstat1;
+
+	tx_status = &desc->ud.ds_tx5212.tx_stat;
+
+	txstat1 = READ_ONCE(tx_status->tx_status_1);
+
+	/* No frame has been send or error */
+	if (unlikely(!(txstat1 & AR5K_DESC_TX_STATUS1_DONE)))
+		return -EINPROGRESS;
+
+	txstat0 = READ_ONCE(tx_status->tx_status_0);
+
+	/*
+	 * Get descriptor status
+	 */
+	ts->ts_tstamp = AR5K_REG_MS(txstat0,
+		AR5K_DESC_TX_STATUS0_SEND_TIMESTAMP);
+	ts->ts_shortretry = AR5K_REG_MS(txstat0,
+		AR5K_DESC_TX_STATUS0_SHORT_RETRY_COUNT);
+	ts->ts_final_retry = AR5K_REG_MS(txstat0,
+		AR5K_DESC_TX_STATUS0_LONG_RETRY_COUNT);
+	ts->ts_seqnum = AR5K_REG_MS(txstat1,
+		AR5K_DESC_TX_STATUS1_SEQ_NUM);
+	ts->ts_rssi = AR5K_REG_MS(txstat1,
+		AR5K_DESC_TX_STATUS1_ACK_SIG_STRENGTH);
+	ts->ts_antenna = (txstat1 &
+		AR5K_DESC_TX_STATUS1_XMIT_ANTENNA_5212) ? 2 : 1;
+	ts->ts_status = 0;
+
+	ts->ts_final_idx = AR5K_REG_MS(txstat1,
+			AR5K_DESC_TX_STATUS1_FINAL_TS_IX_5212);
+
+	/* TX error */
+	if (!(txstat0 & AR5K_DESC_TX_STATUS0_FRAME_XMIT_OK)) {
+		if (txstat0 & AR5K_DESC_TX_STATUS0_EXCESSIVE_RETRIES)
+			ts->ts_status |= AR5K_TXERR_XRETRY;
+
+		if (txstat0 & AR5K_DESC_TX_STATUS0_FIFO_UNDERRUN)
+			ts->ts_status |= AR5K_TXERR_FIFO;
+
+		if (txstat0 & AR5K_DESC_TX_STATUS0_FILTERED)
+			ts->ts_status |= AR5K_TXERR_FILT;
+	}
+
+	return 0;
+}
+
+
+/****************\
+* RX Descriptors *
+\****************/
+
+/**
+ * ath5k_hw_setup_rx_desc() - Initialize an rx control descriptor
+ * @ah: The &struct ath5k_hw
+ * @desc: The &struct ath5k_desc
+ * @size: RX buffer length in bytes
+ * @flags: One of AR5K_RXDESC_* flags
+ */
+int
+ath5k_hw_setup_rx_desc(struct ath5k_hw *ah,
+			struct ath5k_desc *desc,
+			u32 size, unsigned int flags)
+{
+	struct ath5k_hw_rx_ctl *rx_ctl;
+
+	rx_ctl = &desc->ud.ds_rx.rx_ctl;
+
+	/*
+	 * Clear the descriptor
+	 * If we don't clean the status descriptor,
+	 * while scanning we get too many results,
+	 * most of them virtual, after some secs
+	 * of scanning system hangs. M.F.
+	*/
+	memset(&desc->ud.ds_rx, 0, sizeof(struct ath5k_hw_all_rx_desc));
+
+	if (unlikely(size & ~AR5K_DESC_RX_CTL1_BUF_LEN))
+		return -EINVAL;
+
+	/* Setup descriptor */
+	rx_ctl->rx_control_1 = size & AR5K_DESC_RX_CTL1_BUF_LEN;
+
+	if (flags & AR5K_RXDESC_INTREQ)
+		rx_ctl->rx_control_1 |= AR5K_DESC_RX_CTL1_INTREQ;
+
+	return 0;
+}
+
+/**
+ * ath5k_hw_proc_5210_rx_status() - Process the rx status descriptor on 5210/1
+ * @ah: The &struct ath5k_hw
+ * @desc: The &struct ath5k_desc
+ * @rs: The &struct ath5k_rx_status
+ *
+ * Internal function used to process an RX status descriptor
+ * on AR5210/5211 MAC.
+ *
+ * Returns 0 on success or -EINPROGRESS in case we haven't received the who;e
+ * frame yet.
+ */
+static int
+ath5k_hw_proc_5210_rx_status(struct ath5k_hw *ah,
+				struct ath5k_desc *desc,
+				struct ath5k_rx_status *rs)
+{
+	struct ath5k_hw_rx_status *rx_status;
+
+	rx_status = &desc->ud.ds_rx.rx_stat;
+
+	/* No frame received / not ready */
+	if (unlikely(!(rx_status->rx_status_1 &
+			AR5K_5210_RX_DESC_STATUS1_DONE)))
+		return -EINPROGRESS;
+
+	memset(rs, 0, sizeof(struct ath5k_rx_status));
+
+	/*
+	 * Frame receive status
+	 */
+	rs->rs_datalen = rx_status->rx_status_0 &
+		AR5K_5210_RX_DESC_STATUS0_DATA_LEN;
+	rs->rs_rssi = AR5K_REG_MS(rx_status->rx_status_0,
+		AR5K_5210_RX_DESC_STATUS0_RECEIVE_SIGNAL);
+	rs->rs_rate = AR5K_REG_MS(rx_status->rx_status_0,
+		AR5K_5210_RX_DESC_STATUS0_RECEIVE_RATE);
+	rs->rs_more = !!(rx_status->rx_status_0 &
+		AR5K_5210_RX_DESC_STATUS0_MORE);
+	/* TODO: this timestamp is 13 bit, later on we assume 15 bit!
+	 * also the HAL code for 5210 says the timestamp is bits [10..22] of the
+	 * TSF, and extends the timestamp here to 15 bit.
+	 * we need to check on 5210...
+	 */
+	rs->rs_tstamp = AR5K_REG_MS(rx_status->rx_status_1,
+		AR5K_5210_RX_DESC_STATUS1_RECEIVE_TIMESTAMP);
+
+	if (ah->ah_version == AR5K_AR5211)
+		rs->rs_antenna = AR5K_REG_MS(rx_status->rx_status_0,
+				AR5K_5210_RX_DESC_STATUS0_RECEIVE_ANT_5211);
+	else
+		rs->rs_antenna = (rx_status->rx_status_0 &
+				AR5K_5210_RX_DESC_STATUS0_RECEIVE_ANT_5210)
+				? 2 : 1;
+
+	/*
+	 * Key table status
+	 */
+	if (rx_status->rx_status_1 & AR5K_5210_RX_DESC_STATUS1_KEY_INDEX_VALID)
+		rs->rs_keyix = AR5K_REG_MS(rx_status->rx_status_1,
+			AR5K_5210_RX_DESC_STATUS1_KEY_INDEX);
+	else
+		rs->rs_keyix = AR5K_RXKEYIX_INVALID;
+
+	/*
+	 * Receive/descriptor errors
+	 */
+	if (!(rx_status->rx_status_1 &
+			AR5K_5210_RX_DESC_STATUS1_FRAME_RECEIVE_OK)) {
+		if (rx_status->rx_status_1 &
+				AR5K_5210_RX_DESC_STATUS1_CRC_ERROR)
+			rs->rs_status |= AR5K_RXERR_CRC;
+
+		/* only on 5210 */
+		if ((ah->ah_version == AR5K_AR5210) &&
+		    (rx_status->rx_status_1 &
+				AR5K_5210_RX_DESC_STATUS1_FIFO_OVERRUN_5210))
+			rs->rs_status |= AR5K_RXERR_FIFO;
+
+		if (rx_status->rx_status_1 &
+				AR5K_5210_RX_DESC_STATUS1_PHY_ERROR) {
+			rs->rs_status |= AR5K_RXERR_PHY;
+			rs->rs_phyerr = AR5K_REG_MS(rx_status->rx_status_1,
+				AR5K_5210_RX_DESC_STATUS1_PHY_ERROR);
+		}
+
+		if (rx_status->rx_status_1 &
+				AR5K_5210_RX_DESC_STATUS1_DECRYPT_CRC_ERROR)
+			rs->rs_status |= AR5K_RXERR_DECRYPT;
+	}
+
+	return 0;
+}
+
+/**
+ * ath5k_hw_proc_5212_rx_status() - Process the rx status descriptor on 5212
+ * @ah: The &struct ath5k_hw
+ * @desc: The &struct ath5k_desc
+ * @rs: The &struct ath5k_rx_status
+ *
+ * Internal function used to process an RX status descriptor
+ * on AR5212 and later MAC.
+ *
+ * Returns 0 on success or -EINPROGRESS in case we haven't received the who;e
+ * frame yet.
+ */
+static int
+ath5k_hw_proc_5212_rx_status(struct ath5k_hw *ah,
+				struct ath5k_desc *desc,
+				struct ath5k_rx_status *rs)
+{
+	struct ath5k_hw_rx_status *rx_status;
+	u32 rxstat0, rxstat1;
+
+	rx_status = &desc->ud.ds_rx.rx_stat;
+	rxstat1 = READ_ONCE(rx_status->rx_status_1);
+
+	/* No frame received / not ready */
+	if (unlikely(!(rxstat1 & AR5K_5212_RX_DESC_STATUS1_DONE)))
+		return -EINPROGRESS;
+
+	memset(rs, 0, sizeof(struct ath5k_rx_status));
+	rxstat0 = READ_ONCE(rx_status->rx_status_0);
+
+	/*
+	 * Frame receive status
+	 */
+	rs->rs_datalen = rxstat0 & AR5K_5212_RX_DESC_STATUS0_DATA_LEN;
+	rs->rs_rssi = AR5K_REG_MS(rxstat0,
+		AR5K_5212_RX_DESC_STATUS0_RECEIVE_SIGNAL);
+	rs->rs_rate = AR5K_REG_MS(rxstat0,
+		AR5K_5212_RX_DESC_STATUS0_RECEIVE_RATE);
+	rs->rs_antenna = AR5K_REG_MS(rxstat0,
+		AR5K_5212_RX_DESC_STATUS0_RECEIVE_ANTENNA);
+	rs->rs_more = !!(rxstat0 & AR5K_5212_RX_DESC_STATUS0_MORE);
+	rs->rs_tstamp = AR5K_REG_MS(rxstat1,
+		AR5K_5212_RX_DESC_STATUS1_RECEIVE_TIMESTAMP);
+
+	/*
+	 * Key table status
+	 */
+	if (rxstat1 & AR5K_5212_RX_DESC_STATUS1_KEY_INDEX_VALID)
+		rs->rs_keyix = AR5K_REG_MS(rxstat1,
+					   AR5K_5212_RX_DESC_STATUS1_KEY_INDEX);
+	else
+		rs->rs_keyix = AR5K_RXKEYIX_INVALID;
+
+	/*
+	 * Receive/descriptor errors
+	 */
+	if (!(rxstat1 & AR5K_5212_RX_DESC_STATUS1_FRAME_RECEIVE_OK)) {
+		if (rxstat1 & AR5K_5212_RX_DESC_STATUS1_CRC_ERROR)
+			rs->rs_status |= AR5K_RXERR_CRC;
+
+		if (rxstat1 & AR5K_5212_RX_DESC_STATUS1_PHY_ERROR) {
+			rs->rs_status |= AR5K_RXERR_PHY;
+			rs->rs_phyerr = AR5K_REG_MS(rxstat1,
+				AR5K_5212_RX_DESC_STATUS1_PHY_ERROR_CODE);
+			if (!ah->ah_capabilities.cap_has_phyerr_counters)
+				ath5k_ani_phy_error_report(ah, rs->rs_phyerr);
+		}
+
+		if (rxstat1 & AR5K_5212_RX_DESC_STATUS1_DECRYPT_CRC_ERROR)
+			rs->rs_status |= AR5K_RXERR_DECRYPT;
+
+		if (rxstat1 & AR5K_5212_RX_DESC_STATUS1_MIC_ERROR)
+			rs->rs_status |= AR5K_RXERR_MIC;
+	}
+	return 0;
+}
+
+
+/********\
+* Attach *
+\********/
+
+/**
+ * ath5k_hw_init_desc_functions() - Init function pointers inside ah
+ * @ah: The &struct ath5k_hw
+ *
+ * Maps the internal descriptor functions to the function pointers on ah, used
+ * from above. This is used as an abstraction layer to handle the various chips
+ * the same way.
+ */
+int
+ath5k_hw_init_desc_functions(struct ath5k_hw *ah)
+{
+	if (ah->ah_version == AR5K_AR5212) {
+		ah->ah_setup_tx_desc = ath5k_hw_setup_4word_tx_desc;
+		ah->ah_proc_tx_desc = ath5k_hw_proc_4word_tx_status;
+		ah->ah_proc_rx_desc = ath5k_hw_proc_5212_rx_status;
+	} else if (ah->ah_version <= AR5K_AR5211) {
+		ah->ah_setup_tx_desc = ath5k_hw_setup_2word_tx_desc;
+		ah->ah_proc_tx_desc = ath5k_hw_proc_2word_tx_status;
+		ah->ah_proc_rx_desc = ath5k_hw_proc_5210_rx_status;
+	} else
+		return -ENOTSUPP;
+	return 0;
+}