wl1271: add wl1271 driver files

This driver supports the wl1271 chipset from Texas Instruments based on the
WiLink(tm) 6.0 mobile platform.  Support for wl1273 should be relatively easy
to add.  This chipset is designed for embedded devices, with good powersaving
capabilities.  The wl1271 chipset is the successor of wl1251 and supports the
802.11b/g/n standards, but currently this driver supports only b/g.

More information about this chipset can be found here:
http://focus.ti.com/general/docs/wtbu/wtbuproductcontent.tsp?templateId=6123&navigationId=12762&contentId=29993

Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 378 insertions, 0 deletions

diff --git a/drivers/net/wireless/wl12xx/wl1271_tx.c b/drivers/net/wireless/wl12xx/wl1271_tx.c
new file mode 100644
index 00000000000..ff221258b94
--- /dev/null
+++ b/drivers/net/wireless/wl12xx/wl1271_tx.c
@@ -0,0 +1,378 @@
+/*
+ * This file is part of wl1271
+ *
+ * Copyright (C) 2009 Nokia Corporation
+ *
+ * Contact: Luciano Coelho <luciano.coelho@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 "wl1271.h"
+#include "wl1271_spi.h"
+#include "wl1271_reg.h"
+#include "wl1271_ps.h"
+#include "wl1271_tx.h"
+
+static int wl1271_tx_id(struct wl1271 *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 int wl1271_tx_allocate(struct wl1271 *wl, struct sk_buff *skb, u32 extra)
+{
+	struct wl1271_tx_hw_descr *desc;
+	u32 total_len = skb->len + sizeof(struct wl1271_tx_hw_descr) + extra;
+	u32 total_blocks, excluded;
+	int id, ret = -EBUSY;
+
+	/* allocate free identifier for the packet */
+	id = wl1271_tx_id(wl, skb);
+	if (id < 0)
+		return id;
+
+	/* approximate the number of blocks required for this packet
+	   in the firmware */
+	/* FIXME: try to figure out what is done here and make it cleaner */
+	total_blocks = (skb->len) >> TX_HW_BLOCK_SHIFT_DIV;
+	excluded = (total_blocks << 2) + (skb->len & 0xff) + 34;
+	total_blocks += (excluded > 252) ? 2 : 1;
+	total_blocks += TX_HW_BLOCK_SPARE;
+
+	if (total_blocks <= wl->tx_blocks_available) {
+		desc = (struct wl1271_tx_hw_descr *)skb_push(
+			skb, total_len - skb->len);
+
+		desc->extra_mem_blocks = TX_HW_BLOCK_SPARE;
+		desc->total_mem_blocks = total_blocks;
+		desc->id = id;
+
+		wl->tx_blocks_available -= total_blocks;
+
+		ret = 0;
+
+		wl1271_debug(DEBUG_TX,
+			     "tx_allocate: size: %d, blocks: %d, id: %d",
+			     total_len, total_blocks, id);
+	} else
+		wl->tx_frames[id] = NULL;
+
+	return ret;
+}
+
+static int wl1271_tx_fill_hdr(struct wl1271 *wl, struct sk_buff *skb,
+			      u32 extra, struct ieee80211_tx_info *control)
+{
+	struct wl1271_tx_hw_descr *desc;
+	int pad;
+
+	desc = (struct wl1271_tx_hw_descr *) skb->data;
+
+	/* configure packet life time */
+	desc->start_time = jiffies_to_usecs(jiffies) - wl->time_offset;
+	desc->life_time = TX_HW_MGMT_PKT_LIFETIME_TU;
+
+	/* configure the tx attributes */
+	desc->tx_attr = wl->session_counter << TX_HW_ATTR_OFST_SESSION_COUNTER;
+	/* FIXME: do we know the packet priority? can we identify mgmt
+	   packets, and use max prio for them at least? */
+	desc->tid = 0;
+	desc->aid = TX_HW_DEFAULT_AID;
+	desc->reserved = 0;
+
+	/* align the length (and store in terms of words) */
+	pad = WL1271_TX_ALIGN(skb->len);
+	desc->length = pad >> 2;
+
+	/* calculate number of padding bytes */
+	pad = pad - skb->len;
+	desc->tx_attr |= pad << TX_HW_ATTR_OFST_LAST_WORD_PAD;
+
+	wl1271_debug(DEBUG_TX, "tx_fill_hdr: pad: %d", pad);
+	return 0;
+}
+
+static int wl1271_tx_send_packet(struct wl1271 *wl, struct sk_buff *skb,
+				 struct ieee80211_tx_info *control)
+{
+
+	struct wl1271_tx_hw_descr *desc;
+	int len;
+
+	/* FIXME: 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;
+		wl1271_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 {
+			wl1271_info("No handler, fixme!");
+			return -EINVAL;
+		}
+	}
+
+	len = WL1271_TX_ALIGN(skb->len);
+
+	/* perform a fixed address block write with the packet */
+	wl1271_spi_reg_write(wl, WL1271_SLV_MEM_DATA, skb->data, len, true);
+
+	/* write packet new counter into the write access register */
+	wl->tx_packets_count++;
+	wl1271_reg_write32(wl, WL1271_HOST_WR_ACCESS, wl->tx_packets_count);
+
+	desc = (struct wl1271_tx_hw_descr *) skb->data;
+	wl1271_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u (%u words)",
+		     desc->id, skb, len, desc->length);
+
+	return 0;
+}
+
+/* caller must hold wl->mutex */
+static int wl1271_tx_frame(struct wl1271 *wl, struct sk_buff *skb)
+{
+	struct ieee80211_tx_info *info;
+	u32 extra = 0;
+	int ret = 0;
+	u8 idx;
+
+	if (!skb)
+		return -EINVAL;
+
+	info = IEEE80211_SKB_CB(skb);
+
+	if (info->control.hw_key &&
+	    info->control.hw_key->alg == ALG_TKIP)
+		extra = WL1271_TKIP_IV_SPACE;
+
+	if (info->control.hw_key) {
+		idx = info->control.hw_key->hw_key_idx;
+
+		/* FIXME: do we have to do this if we're not using WEP? */
+		if (unlikely(wl->default_key != idx)) {
+			ret = wl1271_cmd_set_default_wep_key(wl, idx);
+			if (ret < 0)
+				return ret;
+		}
+	}
+
+	ret = wl1271_tx_allocate(wl, skb, extra);
+	if (ret < 0)
+		return ret;
+
+	ret = wl1271_tx_fill_hdr(wl, skb, extra, info);
+	if (ret < 0)
+		return ret;
+
+	ret = wl1271_tx_send_packet(wl, skb, info);
+	if (ret < 0)
+		return ret;
+
+	return ret;
+}
+
+void wl1271_tx_work(struct work_struct *work)
+{
+	struct wl1271 *wl = container_of(work, struct wl1271, tx_work);
+	struct sk_buff *skb;
+	bool woken_up = false;
+	int ret;
+
+	mutex_lock(&wl->mutex);
+
+	if (unlikely(wl->state == WL1271_STATE_OFF))
+		goto out;
+
+	while ((skb = skb_dequeue(&wl->tx_queue))) {
+		if (!woken_up) {
+			ret = wl1271_ps_elp_wakeup(wl, false);
+			if (ret < 0)
+				goto out;
+			woken_up = true;
+		}
+
+		ret = wl1271_tx_frame(wl, skb);
+		if (ret == -EBUSY) {
+			/* firmware buffer is full, stop queues */
+			wl1271_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;
+		} else if (wl->tx_queue_stopped) {
+			/* firmware buffer has space, restart queues */
+			wl1271_debug(DEBUG_TX,
+				     "complete_packet: waking queues");
+			ieee80211_wake_queues(wl->hw);
+			wl->tx_queue_stopped = false;
+		}
+	}
+
+out:
+	if (woken_up)
+		wl1271_ps_elp_sleep(wl);
+
+	mutex_unlock(&wl->mutex);
+}
+
+static void wl1271_tx_complete_packet(struct wl1271 *wl,
+				      struct wl1271_tx_hw_res_descr *result)
+{
+
+	struct ieee80211_tx_info *info;
+	struct sk_buff *skb;
+	u32 header_len;
+	int id = result->id;
+
+	/* check for id legality */
+	if (id >= TX_HW_RESULT_QUEUE_LEN || wl->tx_frames[id] == NULL) {
+		wl1271_warning("TX result illegal id: %d", id);
+		return;
+	}
+
+	skb = wl->tx_frames[id];
+	info = IEEE80211_SKB_CB(skb);
+
+	/* update packet status */
+	if (!(info->flags & IEEE80211_TX_CTL_NO_ACK)) {
+		if (result->status == TX_SUCCESS)
+			info->flags |= IEEE80211_TX_STAT_ACK;
+		if (result->status & TX_RETRY_EXCEEDED) {
+			/* FIXME */
+			/* info->status.excessive_retries = 1; */
+			wl->stats.excessive_retries++;
+		}
+	}
+
+	/* FIXME */
+	/* info->status.retry_count = result->ack_failures; */
+	wl->stats.retry_count += result->ack_failures;
+
+	/* get header len */
+	if (info->control.hw_key &&
+	    info->control.hw_key->alg == ALG_TKIP)
+		header_len = WL1271_TKIP_IV_SPACE +
+			sizeof(struct wl1271_tx_hw_descr);
+	else
+		header_len = sizeof(struct wl1271_tx_hw_descr);
+
+	wl1271_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
+		     " status 0x%x",
+		     result->id, skb, result->ack_failures,
+		     result->rate_class_index, result->status);
+
+	/* remove private header from packet */
+	skb_pull(skb, header_len);
+
+	/* return the packet to the stack */
+	ieee80211_tx_status(wl->hw, skb);
+	wl->tx_frames[result->id] = NULL;
+}
+
+/* Called upon reception of a TX complete interrupt */
+void wl1271_tx_complete(struct wl1271 *wl, u32 count)
+{
+	struct wl1271_acx_mem_map *memmap =
+		(struct wl1271_acx_mem_map *)wl->target_mem_map;
+	u32 i;
+
+	wl1271_debug(DEBUG_TX, "tx_complete received, packets: %d", count);
+
+	/* read the tx results from the chipset */
+	wl1271_spi_mem_read(wl, memmap->tx_result,
+			    wl->tx_res_if, sizeof(*wl->tx_res_if));
+
+	/* verify that the result buffer is not getting overrun */
+	if (count > TX_HW_RESULT_QUEUE_LEN) {
+		wl1271_warning("TX result overflow from chipset: %d", count);
+		count = TX_HW_RESULT_QUEUE_LEN;
+	}
+
+	/* process the results */
+	for (i = 0; i < count; i++) {
+		struct wl1271_tx_hw_res_descr *result;
+		u8 offset = wl->tx_results_count & TX_HW_RESULT_QUEUE_LEN_MASK;
+
+		/* process the packet */
+		result =  &(wl->tx_res_if->tx_results_queue[offset]);
+		wl1271_tx_complete_packet(wl, result);
+
+		wl->tx_results_count++;
+	}
+
+	/* write host counter to chipset (to ack) */
+	wl1271_mem_write32(wl, memmap->tx_result +
+			   offsetof(struct wl1271_tx_hw_res_if,
+				    tx_result_host_counter),
+			   wl->tx_res_if->tx_result_fw_counter);
+}
+
+/* caller must hold wl->mutex */
+void wl1271_tx_flush(struct wl1271 *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);
+
+		wl1271_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;
+		}
+}