alistair23-linux/drivers/staging/vt6655/dpc.c

/*
 * Copyright (c) 1996, 2003 VIA Networking Technologies, Inc.
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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.
 *
 * File: dpc.c
 *
 * Purpose: handle dpc rx functions
 *
 * Author: Lyndon Chen
 *
 * Date: May 20, 2003
 *
 * Functions:
 *
 * Revision History:
 *
 */

#include "device.h"
#include "baseband.h"
#include "rf.h"
#include "dpc.h"

static bool vnt_rx_data(struct vnt_private *priv, struct sk_buff *skb,
			u16 bytes_received)
{
	struct ieee80211_hw *hw = priv->hw;
	struct ieee80211_supported_band *sband;
	struct ieee80211_rx_status rx_status = { 0 };
	struct ieee80211_hdr *hdr;
	__le16 fc;
	u8 *rsr, *new_rsr, *rssi;
	__le64 *tsf_time;
	u16 frame_size;
	int ii, r;
	u8 *rx_sts, *rx_rate, *sq;
	u8 *skb_data;
	u8 rate_idx = 0;
	u8 rate[MAX_RATE] = {2, 4, 11, 22, 12, 18, 24, 36, 48, 72, 96, 108};
	long rx_dbm;

	/* [31:16]RcvByteCount ( not include 4-byte Status ) */
	frame_size = le16_to_cpu(*((__le16 *)(skb->data + 2)));
	if (frame_size > 2346 || frame_size < 14) {
		dev_dbg(&priv->pcid->dev, "------- WRONG Length 1\n");
		return false;
	}

	skb_data = (u8 *)skb->data;

	rx_sts = skb_data;
	rx_rate = skb_data + 1;

	sband = hw->wiphy->bands[hw->conf.chandef.chan->band];

	for (r = RATE_1M; r < MAX_RATE; r++) {
		if (*rx_rate == rate[r])
			break;
	}

	priv->rx_rate = r;

	for (ii = 0; ii < sband->n_bitrates; ii++) {
		if (sband->bitrates[ii].hw_value == r) {
			rate_idx = ii;
				break;
		}
	}

	if (ii == sband->n_bitrates) {
		dev_dbg(&priv->pcid->dev, "Wrong RxRate %x\n", *rx_rate);
		return false;
	}

	tsf_time = (__le64 *)(skb_data + bytes_received - 12);
	sq = skb_data + bytes_received - 4;
	new_rsr = skb_data + bytes_received - 3;
	rssi = skb_data + bytes_received - 2;
	rsr = skb_data + bytes_received - 1;
	if (*rsr & (RSR_IVLDTYP | RSR_IVLDLEN))
		return false;

	RFvRSSITodBm(priv, *rssi, &rx_dbm);

	priv->byBBPreEDRSSI = (u8)rx_dbm + 1;
	priv->uCurrRSSI = *rssi;

	skb_pull(skb, 4);
	skb_trim(skb, frame_size);

	rx_status.mactime = le64_to_cpu(*tsf_time);
	rx_status.band = hw->conf.chandef.chan->band;
	rx_status.signal = rx_dbm;
	rx_status.flag = 0;
	rx_status.freq = hw->conf.chandef.chan->center_freq;

	if (!(*rsr & RSR_CRCOK))
		rx_status.flag |= RX_FLAG_FAILED_FCS_CRC;

	hdr = (struct ieee80211_hdr *)(skb->data);
	fc = hdr->frame_control;

	rx_status.rate_idx = rate_idx;

	if (ieee80211_has_protected(fc)) {
		if (priv->byLocalID > REV_ID_VT3253_A1)
			rx_status.flag |= RX_FLAG_DECRYPTED;

		/* Drop packet */
		if (!(*new_rsr & NEWRSR_DECRYPTOK))
			return false;
	}

	memcpy(IEEE80211_SKB_RXCB(skb), &rx_status, sizeof(rx_status));

	ieee80211_rx_irqsafe(priv->hw, skb);

	return true;
}

bool vnt_receive_frame(struct vnt_private *priv, struct vnt_rx_desc *curr_rd)
{
	struct vnt_rd_info *rd_info = curr_rd->rd_info;
	struct sk_buff *skb;
	u16 frame_size;

	skb = rd_info->skb;

	dma_unmap_single(&priv->pcid->dev, rd_info->skb_dma,
			 priv->rx_buf_sz, DMA_FROM_DEVICE);

	frame_size = le16_to_cpu(curr_rd->rd1.req_count)
			- le16_to_cpu(curr_rd->rd0.res_count);

	if ((frame_size > 2364) || (frame_size < 33)) {
		/* Frame Size error drop this packet.*/
		dev_dbg(&priv->pcid->dev, "Wrong frame size %d\n", frame_size);
		dev_kfree_skb_irq(skb);
		return true;
	}

	if (vnt_rx_data(priv, skb, frame_size))
		return true;

	dev_kfree_skb_irq(skb);

	return true;
}