[PATCH v5] Add support for the Atheros AR300x Bluetooth Chip

[suraj <suraj@atheros.com>]

This implements the Atheros Bluetooth serial protocol to
support the AR300x Bluetooth chipsets.
The serial protocol implements enhanced power management
features for the AR300x chipsets. 

Reviewed-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Reviewed-by: Gustavo F. Padovan <gustavo@padovan.org>
Signed-off-by: Suraj <suraj@atheros.com>

---
 drivers/bluetooth/Kconfig     |   14 ++
 drivers/bluetooth/Makefile    |    1 +
 drivers/bluetooth/hci_ath.c   |  378 +++++++++++++++++++++++++++++++++++++++++
 drivers/bluetooth/hci_ldisc.c |    6 +
 drivers/bluetooth/hci_uart.h  |    8 +-
 5 files changed, 406 insertions(+), 1 deletions(-)
 create mode 100755 drivers/bluetooth/hci_ath.c

diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig
index 058fbcc..5546142 100644
--- a/drivers/bluetooth/Kconfig
+++ b/drivers/bluetooth/Kconfig
@@ -58,6 +58,20 @@ config BT_HCIUART_BCSP
 
 	  Say Y here to compile support for HCI BCSP protocol.
 
+config BT_HCIUART_ATH
+	bool "Atheros AR300x serial Bluetooth support"
+	depends on BT_HCIUART
+	help
+	  HCIATH (HCI Atheros) is a serial protocol for communication
+	  between the host and Atheros AR300x Bluetooth devices. The
+	  protocol implements enhaned power management features for the
+	  the AR300x chipsets. it lets the controller chip go to sleep
+	  mode if there is no Bluetooth activity for some time and wakes
+	  up the chip in case of a Bluetooth activity. Enable this option
+	  if you have an UART Atheros AR300x serial device.
+
+	  Say Y here to compile support for HCIATH protocol.
+
 config BT_HCIUART_LL
 	bool "HCILL protocol support"
 	depends on BT_HCIUART
diff --git a/drivers/bluetooth/Makefile b/drivers/bluetooth/Makefile
index 7e5aed5..1481faa 100644
--- a/drivers/bluetooth/Makefile
+++ b/drivers/bluetooth/Makefile
@@ -26,4 +26,5 @@ hci_uart-y				:= hci_ldisc.o
 hci_uart-$(CONFIG_BT_HCIUART_H4)	+= hci_h4.o
 hci_uart-$(CONFIG_BT_HCIUART_BCSP)	+= hci_bcsp.o
 hci_uart-$(CONFIG_BT_HCIUART_LL)	+= hci_ll.o
+hci_uart-$(CONFIG_BT_HCIUART_ATH)	+= hci_ath.o
 hci_uart-objs				:= $(hci_uart-y)
diff --git a/drivers/bluetooth/hci_ath.c b/drivers/bluetooth/hci_ath.c
new file mode 100755
index 0000000..152a1f6
--- /dev/null
+++ b/drivers/bluetooth/hci_ath.c
@@ -0,0 +1,378 @@
+/*
+ * Copyright (c) 2009-2010 Atheros Communications Inc.
+ *
+ *  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.
+ *
+ *  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/errno.h>
+#include <linux/ioctl.h>
+#include <linux/skbuff.h>
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+
+#include "hci_uart.h"
+
+/* HCIATH receiver States */
+#define HCIATH_W4_PACKET_TYPE			0
+#define HCIATH_W4_EVENT_HDR			1
+#define HCIATH_W4_ACL_HDR			2
+#define HCIATH_W4_SCO_HDR			3
+#define HCIATH_W4_DATA				4
+
+struct ath_struct {
+	struct hci_uart *hu;
+	unsigned int rx_state;
+	unsigned int rx_count;
+	unsigned int cur_sleep;
+
+	spinlock_t hciath_lock;
+	struct sk_buff *rx_skb;
+	struct sk_buff_head txq;
+	wait_queue_head_t wqevt;
+	struct work_struct ctxtsw;
+};
+
+static int ath_wakeup_ar3001(struct tty_struct *tty)
+{
+	struct termios settings;
+	int status = tty->driver->ops->tiocmget(tty, NULL);
+
+	if (status & TIOCM_CTS)
+		return status;
+
+	n_tty_ioctl_helper(tty, NULL, TCGETS, (unsigned long)&settings);
+
+	/* Disable Automatic RTSCTS */
+	settings.c_cflag &= ~CRTSCTS;
+	n_tty_ioctl_helper(tty, NULL, TCSETS, (unsigned long)&settings);
+
+	status = tty->driver->ops->tiocmget(tty, NULL);
+
+	/* Clear RTS first */
+	tty->driver->ops->tiocmset(tty, NULL, 0x00, TIOCM_RTS);
+	mdelay(20);
+
+	status = tty->driver->ops->tiocmget(tty, NULL);
+
+	/* Set RTS, wake up board */
+	tty->driver->ops->tiocmset(tty, NULL, TIOCM_RTS, 0x00);
+	mdelay(20);
+
+	status = tty->driver->ops->tiocmget(tty, NULL);
+
+	n_tty_ioctl_helper(tty, NULL, TCGETS, (unsigned long)&settings);
+
+	settings.c_cflag |= CRTSCTS;
+	n_tty_ioctl_helper(tty, NULL, TCSETS, (unsigned long)&settings);
+
+	return status;
+}
+
+static void ath_hci_uart_work(struct work_struct *work)
+{
+	int status;
+	struct ath_struct *ath;
+	struct hci_uart *hu;
+	struct tty_struct *tty;
+
+	ath = container_of(work, struct ath_struct, ctxtsw);
+
+	hu = ath->hu;
+	tty = hu->tty;
+
+	/* verify and wake up controller */
+	if (ath->cur_sleep) {
+		status = ath_wakeup_ar3001(tty);
+
+		if (!(status & TIOCM_CTS))
+			return;
+	}
+
+	/* Ready to send Data */
+	clear_bit(HCI_UART_SENDING, &hu->tx_state);
+	hci_uart_tx_wakeup(hu);
+}
+
+/* Initialize protocol */
+static int ath_open(struct hci_uart *hu)
+{
+	struct ath_struct *ath;
+
+	BT_DBG("hu %p", hu);
+
+	ath = kzalloc(sizeof(*ath), GFP_ATOMIC);
+	if (!ath)
+		return -ENOMEM;
+
+	skb_queue_head_init(&ath->txq);
+	spin_lock_init(&ath->hciath_lock);
+
+	hu->priv = ath;
+	ath->hu = hu;
+
+	init_waitqueue_head(&ath->wqevt);
+	INIT_WORK(&ath->ctxtsw, ath_hci_uart_work);
+
+	return 0;
+}
+
+/* Flush protocol data */
+static int ath_flush(struct hci_uart *hu)
+{
+	struct ath_struct *ath = hu->priv;
+
+	BT_DBG("hu %p", hu);
+
+	skb_queue_purge(&ath->txq);
+
+	return 0;
+}
+
+/* Close protocol */
+static int ath_close(struct hci_uart *hu)
+{
+	struct ath_struct *ath = hu->priv;
+
+	BT_DBG("hu %p", hu);
+
+	skb_queue_purge(&ath->txq);
+
+	kfree_skb(ath->rx_skb);
+
+	cancel_work_sync(&ath->ctxtsw);
+
+	hu->priv = NULL;
+	kfree(ath);
+
+	return 0;
+}
+
+/* Enqueue frame for transmittion */
+static int ath_enqueue(struct hci_uart *hu, struct sk_buff *skb)
+{
+	struct ath_struct *ath = hu->priv;
+
+	if (bt_cb(skb)->pkt_type == HCI_SCODATA_PKT) {
+
+		/* Discard SCO packet. AR300x does not support SCO over HCI */
+		BT_DBG("SCO Packet over HCI received Dropping");
+
+		kfree(skb);
+
+		return 0;
+	}
+
+	BT_DBG("hu %p skb %p", hu, skb);
+
+	/* Prepend skb with frame type */
+	memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1);
+
+	skb_queue_tail(&ath->txq, skb);
+	set_bit(HCI_UART_SENDING, &hu->tx_state);
+
+	schedule_work(&ath->ctxtsw);
+
+	return 0;
+}
+
+static struct sk_buff *ath_dequeue(struct hci_uart *hu)
+{
+	struct ath_struct *ath = hu->priv;
+	struct sk_buff *skbuf;
+
+	skbuf = skb_dequeue(&ath->txq);
+
+	if (!skbuf)
+		return NULL;
+
+	/*
+	 * Check if the HCI command is  HCI sleep enable and
+	 * update the sleep enable flag with command parameter.
+	 *
+	 * Value of sleep enable flag will be used later
+	 * to verify if controller has to be woken up before
+	 * sending any packet.
+	 */
+	if (skbuf->data[0] == 0x01 &&
+	    skbuf->data[1] == 0x04 &&
+	    skbuf->data[2] == 0xFC)
+		ath->cur_sleep = skbuf->data[4];
+
+	return skbuf;
+}
+
+static void ath_check_data_len(struct ath_struct *ath, int len)
+{
+	int room = skb_tailroom(ath->rx_skb);
+
+	BT_DBG("len %d room %d", len, room);
+
+	if (len > room) {
+		BT_ERR("Data length is too large");
+		kfree_skb(ath->rx_skb);
+		ath->rx_state = HCIATH_W4_PACKET_TYPE;
+		ath->rx_skb = NULL;
+		ath->rx_count = 0;
+	} else {
+		ath->rx_state = HCIATH_W4_DATA;
+		ath->rx_count = len;
+	}
+}
+
+/* Recv data */
+static int ath_recv(struct hci_uart *hu, void *data, int count)
+{
+	struct ath_struct *ath = hu->priv;
+	char *ptr = data;
+	struct hci_event_hdr *eh;
+	struct hci_acl_hdr *ah;
+	struct hci_sco_hdr *sh;
+	int len, type, dlen;
+
+	BT_DBG("hu %p count %d rx_state %d rx_count %d", hu, count,
+	       ath->rx_state, ath->rx_count);
+
+	while (count) {
+		if (ath->rx_count) {
+
+			len = min_t(unsigned int, ath->rx_count, count);
+			memcpy(skb_put(ath->rx_skb, len), ptr, len);
+			ath->rx_count -= len;
+			count -= len;
+			ptr += len;
+
+			if (ath->rx_count)
+				continue;
+			switch (ath->rx_state) {
+			case HCIATH_W4_DATA:
+				hci_recv_frame(ath->rx_skb);
+				ath->rx_state = HCIATH_W4_PACKET_TYPE;
+				ath->rx_skb = NULL;
+				ath->rx_count = 0;
+				continue;
+
+			case HCIATH_W4_EVENT_HDR:
+				eh = hci_event_hdr(ath->rx_skb);
+
+				BT_DBG("Event header: evt 0x%2.2x plen %d",
+				       eh->evt, eh->plen);
+
+				ath_check_data_len(ath, eh->plen);
+				continue;
+
+			case HCIATH_W4_ACL_HDR:
+				ah = hci_acl_hdr(ath->rx_skb);
+				dlen = __le16_to_cpu(ah->dlen);
+
+				BT_DBG("ACL header: dlen %d", dlen);
+
+				ath_check_data_len(ath, dlen);
+				continue;
+
+			case HCIATH_W4_SCO_HDR:
+				sh = hci_sco_hdr(ath->rx_skb);
+
+				BT_DBG("SCO header: dlen %d", sh->dlen);
+
+				ath_check_data_len(ath, sh->dlen);
+				continue;
+
+			}
+		}
+
+		/* HCIATH_W4_PACKET_TYPE */
+		switch (*ptr) {
+		case HCI_EVENT_PKT:
+			BT_DBG("Event packet");
+			ath->rx_state = HCIATH_W4_EVENT_HDR;
+			ath->rx_count = HCI_EVENT_HDR_SIZE;
+			type = HCI_EVENT_PKT;
+			break;
+
+		case HCI_ACLDATA_PKT:
+			BT_DBG("ACL packet");
+			ath->rx_state = HCIATH_W4_ACL_HDR;
+			ath->rx_count = HCI_ACL_HDR_SIZE;
+			type = HCI_ACLDATA_PKT;
+			break;
+
+		case HCI_SCODATA_PKT:
+			BT_DBG("SCO packet");
+			ath->rx_state = HCIATH_W4_SCO_HDR;
+			ath->rx_count = HCI_SCO_HDR_SIZE;
+			type = HCI_SCODATA_PKT;
+			break;
+
+		default:
+			BT_ERR("Unknown HCI packet type %2.2x", (__u8) *ptr);
+			hu->hdev->stat.err_rx++;
+			ptr++;
+			count--;
+			continue;
+
+		};
+		ptr++;
+		count--;
+
+		/* Allocate packet */
+		ath->rx_skb = bt_skb_alloc(HCI_MAX_FRAME_SIZE, GFP_ATOMIC);
+		if (!ath->rx_skb) {
+			BT_ERR("Can't allocate mem for new packet");
+			ath->rx_state = HCIATH_W4_PACKET_TYPE;
+			ath->rx_count = 0;
+
+			return -ENOMEM;
+		}
+		ath->rx_skb->dev = (void *)hu->hdev;
+		bt_cb(ath->rx_skb)->pkt_type = type;
+	}
+
+	return count;
+}
+
+static struct hci_uart_proto athp = {
+	.id = HCI_UART_ATH,
+	.open = ath_open,
+	.close = ath_close,
+	.recv = ath_recv,
+	.enqueue = ath_enqueue,
+	.dequeue = ath_dequeue,
+	.flush = ath_flush,
+};
+
+int ath_init(void)
+{
+	int err = hci_uart_register_proto(&athp);
+
+	if (!err)
+		BT_INFO("HCIATH protocol initialized");
+	else
+		BT_ERR("HCIATH protocol registration failed");
+
+	return err;
+}
+
+int ath_deinit(void)
+{
+	return hci_uart_unregister_proto(&athp);
+}
diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index 76a1abb..7dd76d1 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -542,6 +542,9 @@ static int __init hci_uart_init(void)
 #ifdef CONFIG_BT_HCIUART_LL
 	ll_init();
 #endif
+#ifdef CONFIG_BT_HCIUART_ATH
+	ath_init();
+#endif
 
 	return 0;
 }
@@ -559,6 +562,9 @@ static void __exit hci_uart_exit(void)
 #ifdef CONFIG_BT_HCIUART_LL
 	ll_deinit();
 #endif
+#ifdef CONFIG_BT_HCIUART_ATH
+	ath_deinit();
+#endif
 
 	/* Release tty registration of line discipline */
 	if ((err = tty_unregister_ldisc(N_HCI)))
diff --git a/drivers/bluetooth/hci_uart.h b/drivers/bluetooth/hci_uart.h
index 50113db..385537f 100644
--- a/drivers/bluetooth/hci_uart.h
+++ b/drivers/bluetooth/hci_uart.h
@@ -33,13 +33,14 @@
 #define HCIUARTGETDEVICE	_IOR('U', 202, int)
 
 /* UART protocols */
-#define HCI_UART_MAX_PROTO	5
+#define HCI_UART_MAX_PROTO	6
 
 #define HCI_UART_H4	0
 #define HCI_UART_BCSP	1
 #define HCI_UART_3WIRE	2
 #define HCI_UART_H4DS	3
 #define HCI_UART_LL	4
+#define HCI_UART_ATH	5
 
 struct hci_uart;
 
@@ -91,3 +92,8 @@ int bcsp_deinit(void);
 int ll_init(void);
 int ll_deinit(void);
 #endif
+
+#ifdef CONFIG_BT_HCIUART_ATH
+int ath_init(void);
+int ath_deinit(void);
+#endif
-- 
1.7.0