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>

1 files changed, 557 insertions, 0 deletions

diff --git a/drivers/net/wireless/wl12xx/tx.c b/drivers/net/wireless/wl12xx/tx.c
new file mode 100644
index 00000000000..62145e205a8
--- /dev/null
+++ b/drivers/net/wireless/wl12xx/tx.c
@@ -0,0 +1,557 @@
+/*
+ * 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
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include "wl12xx.h"
+#include "reg.h"
+#include "spi.h"
+#include "tx.h"
+#include "ps.h"
+
+static bool wl12xx_tx_double_buffer_busy(struct wl12xx *wl, u32 data_out_count)
+{
+	int used, data_in_count;
+
+	data_in_count = wl->data_in_count;
+
+	if (data_in_count < data_out_count)
+		/* data_in_count has wrapped */
+		data_in_count += TX_STATUS_DATA_OUT_COUNT_MASK + 1;
+
+	used = data_in_count - data_out_count;
+
+	WARN_ON(used < 0);
+	WARN_ON(used > DP_TX_PACKET_RING_CHUNK_NUM);
+
+	if (used >= DP_TX_PACKET_RING_CHUNK_NUM)
+		return true;
+	else
+		return false;
+}
+
+static int wl12xx_tx_path_status(struct wl12xx *wl)
+{
+	u32 status, addr, data_out_count;
+	bool busy;
+
+	addr = wl->data_path->tx_control_addr;
+	status = wl12xx_mem_read32(wl, addr);
+	data_out_count = status & TX_STATUS_DATA_OUT_COUNT_MASK;
+	busy = wl12xx_tx_double_buffer_busy(wl, data_out_count);
+
+	if (busy)
+		return -EBUSY;
+
+	return 0;
+}
+
+static int wl12xx_tx_id(struct wl12xx *wl, struct sk_buff *skb)
+{
+	int i;
+
+	for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
+		if (wl->tx_frames[i] == NULL) {
+			wl->tx_frames[i] = skb;
+			return i;
+		}
+
+	return -EBUSY;
+}
+
+static void wl12xx_tx_control(struct tx_double_buffer_desc *tx_hdr,
+			      struct ieee80211_tx_info *control, u16 fc)
+{
+	*(u16 *)&tx_hdr->control = 0;
+
+	tx_hdr->control.rate_policy = 0;
+
+	/* 802.11 packets */
+	tx_hdr->control.packet_type = 0;
+
+	if (control->flags & IEEE80211_TX_CTL_NO_ACK)
+		tx_hdr->control.ack_policy = 1;
+
+	tx_hdr->control.tx_complete = 1;
+
+	if ((fc & IEEE80211_FTYPE_DATA) &&
+	    ((fc & IEEE80211_STYPE_QOS_DATA) ||
+	     (fc & IEEE80211_STYPE_QOS_NULLFUNC)))
+		tx_hdr->control.qos = 1;
+}
+
+/* RSN + MIC = 8 + 8 = 16 bytes (worst case - AES). */
+#define MAX_MSDU_SECURITY_LENGTH      16
+#define MAX_MPDU_SECURITY_LENGTH      16
+#define WLAN_QOS_HDR_LEN              26
+#define MAX_MPDU_HEADER_AND_SECURITY  (MAX_MPDU_SECURITY_LENGTH + \
+				       WLAN_QOS_HDR_LEN)
+#define HW_BLOCK_SIZE                 252
+static void wl12xx_tx_frag_block_num(struct tx_double_buffer_desc *tx_hdr)
+{
+	u16 payload_len, frag_threshold, mem_blocks;
+	u16 num_mpdus, mem_blocks_per_frag;
+
+	frag_threshold = IEEE80211_MAX_FRAG_THRESHOLD;
+	tx_hdr->frag_threshold = cpu_to_le16(frag_threshold);
+
+	payload_len = tx_hdr->length + MAX_MSDU_SECURITY_LENGTH;
+
+	if (payload_len > frag_threshold) {
+		mem_blocks_per_frag =
+			((frag_threshold + MAX_MPDU_HEADER_AND_SECURITY) /
+			 HW_BLOCK_SIZE) + 1;
+		num_mpdus = payload_len / frag_threshold;
+		mem_blocks = num_mpdus * mem_blocks_per_frag;
+		payload_len -= num_mpdus * frag_threshold;
+		num_mpdus++;
+
+	} else {
+		mem_blocks_per_frag = 0;
+		mem_blocks = 0;
+		num_mpdus = 1;
+	}
+
+	mem_blocks += (payload_len / HW_BLOCK_SIZE) + 1;
+
+	if (num_mpdus > 1)
+		mem_blocks += min(num_mpdus, mem_blocks_per_frag);
+
+	tx_hdr->num_mem_blocks = mem_blocks;
+}
+
+static int wl12xx_tx_fill_hdr(struct wl12xx *wl, struct sk_buff *skb,
+			      struct ieee80211_tx_info *control)
+{
+	struct tx_double_buffer_desc *tx_hdr;
+	struct ieee80211_rate *rate;
+	int id;
+	u16 fc;
+
+	if (!skb)
+		return -EINVAL;
+
+	id = wl12xx_tx_id(wl, skb);
+	if (id < 0)
+		return id;
+
+	fc = *(u16 *)skb->data;
+	tx_hdr = (struct tx_double_buffer_desc *) skb_push(skb,
+							   sizeof(*tx_hdr));
+
+	tx_hdr->length = cpu_to_le16(skb->len - sizeof(*tx_hdr));
+	rate = ieee80211_get_tx_rate(wl->hw, control);
+	tx_hdr->rate = cpu_to_le16(rate->hw_value);
+	tx_hdr->expiry_time = cpu_to_le32(1 << 16);
+	tx_hdr->id = id;
+
+	/* FIXME: how to get the correct queue id? */
+	tx_hdr->xmit_queue = 0;
+
+	wl12xx_tx_control(tx_hdr, control, fc);
+	wl12xx_tx_frag_block_num(tx_hdr);
+
+	return 0;
+}
+
+/* We copy the packet to the target */
+static int wl12xx_tx_send_packet(struct wl12xx *wl, struct sk_buff *skb,
+				 struct ieee80211_tx_info *control)
+{
+	struct tx_double_buffer_desc *tx_hdr;
+	int len;
+	u32 addr;
+
+	if (!skb)
+		return -EINVAL;
+
+	tx_hdr = (struct tx_double_buffer_desc *) skb->data;
+
+	if (control->control.hw_key &&
+	    control->control.hw_key->alg == ALG_TKIP) {
+		int hdrlen;
+		u16 fc;
+		u8 *pos;
+
+		fc = *(u16 *)(skb->data + sizeof(*tx_hdr));
+		tx_hdr->length += WL12XX_TKIP_IV_SPACE;
+
+		hdrlen = ieee80211_hdrlen(fc);
+
+		pos = skb_push(skb, WL12XX_TKIP_IV_SPACE);
+		memmove(pos, pos + WL12XX_TKIP_IV_SPACE,
+			sizeof(*tx_hdr) + hdrlen);
+	}
+
+	/* Revisit. This is a workaround for getting non-aligned packets.
+	   This happens at least with EAPOL packets from the user space.
+	   Our DMA requires packets to be aligned on a 4-byte boundary.
+	*/
+	if (unlikely((long)skb->data & 0x03)) {
+		int offset = (4 - (long)skb->data) & 0x03;
+		wl12xx_debug(DEBUG_TX, "skb offset %d", offset);
+
+		/* check whether the current skb can be used */
+		if (!skb_cloned(skb) && (skb_tailroom(skb) >= offset)) {
+			unsigned char *src = skb->data;
+
+			/* align the buffer on a 4-byte boundary */
+			skb_reserve(skb, offset);
+			memmove(skb->data, src, skb->len);
+		} else {
+			wl12xx_info("No handler, fixme!");
+			return -EINVAL;
+		}
+	}
+
+	/* Our skb->data at this point includes the HW header */
+	len = WL12XX_TX_ALIGN(skb->len);
+
+	if (wl->data_in_count & 0x1)
+		addr = wl->data_path->tx_packet_ring_addr +
+			wl->data_path->tx_packet_ring_chunk_size;
+	else
+		addr = wl->data_path->tx_packet_ring_addr;
+
+	wl12xx_spi_mem_write(wl, addr, skb->data, len);
+
+	wl12xx_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u rate 0x%x",
+		     tx_hdr->id, skb, tx_hdr->length, tx_hdr->rate);
+
+	return 0;
+}
+
+static void wl12xx_tx_trigger(struct wl12xx *wl)
+{
+	u32 data, addr;
+
+	if (wl->data_in_count & 0x1) {
+		addr = ACX_REG_INTERRUPT_TRIG_H;
+		data = INTR_TRIG_TX_PROC1;
+	} else {
+		addr = ACX_REG_INTERRUPT_TRIG;
+		data = INTR_TRIG_TX_PROC0;
+	}
+
+	wl12xx_reg_write32(wl, addr, data);
+
+	/* Bumping data in */
+	wl->data_in_count = (wl->data_in_count + 1) &
+		TX_STATUS_DATA_OUT_COUNT_MASK;
+}
+
+/* caller must hold wl->mutex */
+static int wl12xx_tx_frame(struct wl12xx *wl, struct sk_buff *skb)
+{
+	struct ieee80211_tx_info *info;
+	int ret = 0;
+	u8 idx;
+
+	info = IEEE80211_SKB_CB(skb);
+
+	if (info->control.hw_key) {
+		idx = info->control.hw_key->hw_key_idx;
+		if (unlikely(wl->default_key != idx)) {
+			ret = wl12xx_acx_default_key(wl, idx);
+			if (ret < 0)
+				return ret;
+		}
+	}
+
+	ret = wl12xx_tx_path_status(wl);
+	if (ret < 0)
+		return ret;
+
+	ret = wl12xx_tx_fill_hdr(wl, skb, info);
+	if (ret < 0)
+		return ret;
+
+	ret = wl12xx_tx_send_packet(wl, skb, info);
+	if (ret < 0)
+		return ret;
+
+	wl12xx_tx_trigger(wl);
+
+	return ret;
+}
+
+void wl12xx_tx_work(struct work_struct *work)
+{
+	struct wl12xx *wl = container_of(work, struct wl12xx, tx_work);
+	struct sk_buff *skb;
+	bool woken_up = false;
+	int ret;
+
+	mutex_lock(&wl->mutex);
+
+	if (unlikely(wl->state == WL12XX_STATE_OFF))
+		goto out;
+
+	while ((skb = skb_dequeue(&wl->tx_queue))) {
+		if (!woken_up) {
+			wl12xx_ps_elp_wakeup(wl);
+			woken_up = true;
+		}
+
+		ret = wl12xx_tx_frame(wl, skb);
+		if (ret == -EBUSY) {
+			/* firmware buffer is full, stop queues */
+			wl12xx_debug(DEBUG_TX, "tx_work: fw buffer full, "
+				     "stop queues");
+			ieee80211_stop_queues(wl->hw);
+			wl->tx_queue_stopped = true;
+			skb_queue_head(&wl->tx_queue, skb);
+			goto out;
+		} else if (ret < 0) {
+			dev_kfree_skb(skb);
+			goto out;
+		}
+	}
+
+out:
+	if (woken_up)
+		wl12xx_ps_elp_sleep(wl);
+
+	mutex_unlock(&wl->mutex);
+}
+
+static const char *wl12xx_tx_parse_status(u8 status)
+{
+	/* 8 bit status field, one character per bit plus null */
+	static char buf[9];
+	int i = 0;
+
+	memset(buf, 0, sizeof(buf));
+
+	if (status & TX_DMA_ERROR)
+		buf[i++] = 'm';
+	if (status & TX_DISABLED)
+		buf[i++] = 'd';
+	if (status & TX_RETRY_EXCEEDED)
+		buf[i++] = 'r';
+	if (status & TX_TIMEOUT)
+		buf[i++] = 't';
+	if (status & TX_KEY_NOT_FOUND)
+		buf[i++] = 'k';
+	if (status & TX_ENCRYPT_FAIL)
+		buf[i++] = 'e';
+	if (status & TX_UNAVAILABLE_PRIORITY)
+		buf[i++] = 'p';
+
+	/* bit 0 is unused apparently */
+
+	return buf;
+}
+
+static void wl12xx_tx_packet_cb(struct wl12xx *wl,
+				struct tx_result *result)
+{
+	struct ieee80211_tx_info *info;
+	struct sk_buff *skb;
+	int hdrlen, ret;
+	u8 *frame;
+
+	skb = wl->tx_frames[result->id];
+	if (skb == NULL) {
+		wl12xx_error("SKB for packet %d is NULL", result->id);
+		return;
+	}
+
+	info = IEEE80211_SKB_CB(skb);
+
+	if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
+	    (result->status == TX_SUCCESS))
+		info->flags |= IEEE80211_TX_STAT_ACK;
+
+	info->status.rates[0].count = result->ack_failures + 1;
+	wl->stats.retry_count += result->ack_failures;
+
+	/*
+	 * We have to remove our private TX header before pushing
+	 * the skb back to mac80211.
+	 */
+	frame = skb_pull(skb, sizeof(struct tx_double_buffer_desc));
+	if (info->control.hw_key &&
+	    info->control.hw_key->alg == ALG_TKIP) {
+		hdrlen = ieee80211_get_hdrlen_from_skb(skb);
+		memmove(frame + WL12XX_TKIP_IV_SPACE, frame, hdrlen);
+		skb_pull(skb, WL12XX_TKIP_IV_SPACE);
+	}
+
+	wl12xx_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
+		     " status 0x%x (%s)",
+		     result->id, skb, result->ack_failures, result->rate,
+		     result->status, wl12xx_tx_parse_status(result->status));
+
+
+	ieee80211_tx_status(wl->hw, skb);
+
+	wl->tx_frames[result->id] = NULL;
+
+	if (wl->tx_queue_stopped) {
+		wl12xx_debug(DEBUG_TX, "cb: queue was stopped");
+
+		skb = skb_dequeue(&wl->tx_queue);
+
+		/* The skb can be NULL because tx_work might have been
+		   scheduled before the queue was stopped making the
+		   queue empty */
+
+		if (skb) {
+			ret = wl12xx_tx_frame(wl, skb);
+			if (ret == -EBUSY) {
+				/* firmware buffer is still full */
+				wl12xx_debug(DEBUG_TX, "cb: fw buffer "
+					     "still full");
+				skb_queue_head(&wl->tx_queue, skb);
+				return;
+			} else if (ret < 0) {
+				dev_kfree_skb(skb);
+				return;
+			}
+		}
+
+		wl12xx_debug(DEBUG_TX, "cb: waking queues");
+		ieee80211_wake_queues(wl->hw);
+		wl->tx_queue_stopped = false;
+	}
+}
+
+/* Called upon reception of a TX complete interrupt */
+void wl12xx_tx_complete(struct wl12xx *wl)
+{
+	int i, result_index, num_complete = 0;
+	struct tx_result result[FW_TX_CMPLT_BLOCK_SIZE], *result_ptr;
+
+	if (unlikely(wl->state != WL12XX_STATE_ON))
+		return;
+
+	/* First we read the result */
+	wl12xx_spi_mem_read(wl, wl->data_path->tx_complete_addr,
+			    result, sizeof(result));
+
+	result_index = wl->next_tx_complete;
+
+	for (i = 0; i < ARRAY_SIZE(result); i++) {
+		result_ptr = &result[result_index];
+
+		if (result_ptr->done_1 == 1 &&
+		    result_ptr->done_2 == 1) {
+			wl12xx_tx_packet_cb(wl, result_ptr);
+
+			result_ptr->done_1 = 0;
+			result_ptr->done_2 = 0;
+
+			result_index = (result_index + 1) &
+				(FW_TX_CMPLT_BLOCK_SIZE - 1);
+			num_complete++;
+		} else {
+			break;
+		}
+	}
+
+	/* Every completed frame needs to be acknowledged */
+	if (num_complete) {
+		/*
+		 * If we've wrapped, we have to clear
+		 * the results in 2 steps.
+		 */
+		if (result_index > wl->next_tx_complete) {
+			/* Only 1 write is needed */
+			wl12xx_spi_mem_write(wl,
+					     wl->data_path->tx_complete_addr +
+					     (wl->next_tx_complete *
+					      sizeof(struct tx_result)),
+					     &result[wl->next_tx_complete],
+					     num_complete *
+					     sizeof(struct tx_result));
+
+
+		} else if (result_index < wl->next_tx_complete) {
+			/* 2 writes are needed */
+			wl12xx_spi_mem_write(wl,
+					     wl->data_path->tx_complete_addr +
+					     (wl->next_tx_complete *
+					      sizeof(struct tx_result)),
+					     &result[wl->next_tx_complete],
+					     (FW_TX_CMPLT_BLOCK_SIZE -
+					      wl->next_tx_complete) *
+					     sizeof(struct tx_result));
+
+			wl12xx_spi_mem_write(wl,
+					     wl->data_path->tx_complete_addr,
+					     result,
+					     (num_complete -
+					      FW_TX_CMPLT_BLOCK_SIZE +
+					      wl->next_tx_complete) *
+					     sizeof(struct tx_result));
+
+		} else {
+			/* We have to write the whole array */
+			wl12xx_spi_mem_write(wl,
+					     wl->data_path->tx_complete_addr,
+					     result,
+					     FW_TX_CMPLT_BLOCK_SIZE *
+					     sizeof(struct tx_result));
+		}
+
+	}
+
+	wl->next_tx_complete = result_index;
+}
+
+/* caller must hold wl->mutex */
+void wl12xx_tx_flush(struct wl12xx *wl)
+{
+	int i;
+	struct sk_buff *skb;
+	struct ieee80211_tx_info *info;
+
+	/* TX failure */
+/* 	control->flags = 0; FIXME */
+
+	while ((skb = skb_dequeue(&wl->tx_queue))) {
+		info = IEEE80211_SKB_CB(skb);
+
+		wl12xx_debug(DEBUG_TX, "flushing skb 0x%p", skb);
+
+		if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
+				continue;
+
+		ieee80211_tx_status(wl->hw, skb);
+	}
+
+	for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
+		if (wl->tx_frames[i] != NULL) {
+			skb = wl->tx_frames[i];
+			info = IEEE80211_SKB_CB(skb);
+
+			if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
+				continue;
+
+			ieee80211_tx_status(wl->hw, skb);
+			wl->tx_frames[i] = NULL;
+		}
+}