Bluetooth: Support for Atheros AR300x serial chip

Implements Atheros AR300x serial HCI protocol.

This protocol extends H4 serial protocol to implement enhanced power
management features supported by Atheros AR300x serial Bluetooth chipsets.

Signed-off-by: Suraj Sumangala <[e-mail]>
Signed-off-by: Marcel Holtmann <[e-mail]>

drivers/bluetooth/Kconfig

···
 
 	  Say Y here to compile support for HCI BCSP protocol.
 
+config BT_HCIUART_ATH3K
+	bool "Atheros AR300x serial support"
+	depends on BT_HCIUART
+	help
+	  HCIATH3K (HCI Atheros AR300x) is a serial protocol for
+	  communication between host and Atheros AR300x Bluetooth devices.
+	  This protocol enables AR300x chips to be enabled with
+	  power management support.
+	  Enable this if you have Atheros AR300x serial Bluetooth device.
+
+	  Say Y here to compile support for HCI UART ATH3K protocol.
+
 config BT_HCIUART_LL
 	bool "HCILL protocol support"
 	depends on BT_HCIUART

drivers/bluetooth/Makefile

···
 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_ATH3K)	+= hci_ath.o
 hci_uart-objs				:= $(hci_uart-y)

drivers/bluetooth/hci_ath.c

···
+/*
+ *  Atheros Communication Bluetooth HCIATH3K UART protocol
+ *
+ *  HCIATH3K (HCI Atheros AR300x Protocol) is a Atheros Communication's
+ *  power management protocol extension to H4 to support AR300x Bluetooth Chip.
+ *
+ *  Copyright (c) 2009-2010 Atheros Communications Inc.
+ *
+ *  Acknowledgements:
+ *  This file is based on hci_h4.c, which was written
+ *  by Maxim Krasnyansky and Marcel Holtmann.
+ *
+ *  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"
+
+struct ath_struct {
+	struct hci_uart *hu;
+	unsigned int cur_sleep;
+
+	struct sk_buff_head txq;
+	struct work_struct ctxtsw;
+};
+
+static int ath_wakeup_ar3k(struct tty_struct *tty)
+{
+	struct termios settings;
+	int status = tty->driver->ops->tiocmget(tty, NULL);
+
+	if (status & TIOCM_CTS)
+		return status;
+
+	/* Disable Automatic RTSCTS */
+	n_tty_ioctl_helper(tty, NULL, TCGETS, (unsigned long)&settings);
+	settings.c_cflag &= ~CRTSCTS;
+	n_tty_ioctl_helper(tty, NULL, TCSETS, (unsigned long)&settings);
+
+	/* Clear RTS first */
+	status = tty->driver->ops->tiocmget(tty, NULL);
+	tty->driver->ops->tiocmset(tty, NULL, 0x00, TIOCM_RTS);
+	mdelay(20);
+
+	/* Set RTS, wake up board */
+	status = tty->driver->ops->tiocmget(tty, NULL);
+	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_ar3k(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);
+
+	hu->priv = ath;
+	ath->hu = hu;
+
+	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);
+
+	cancel_work_sync(&ath->ctxtsw);
+
+	hu->priv = NULL;
+	kfree(ath);
+
+	return 0;
+}
+
+#define HCI_OP_ATH_SLEEP 0xFC04
+
+/* 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) {
+		kfree(skb);
+		return 0;
+	}
+
+	/*
+	 * Update power management enable flag with parameters of
+	 * HCI sleep enable vendor specific HCI command.
+	 */
+	if (bt_cb(skb)->pkt_type == HCI_COMMAND_PKT) {
+		struct hci_command_hdr *hdr = (void *)skb->data;
+
+		if (__le16_to_cpu(hdr->opcode) == HCI_OP_ATH_SLEEP)
+			ath->cur_sleep = skb->data[HCI_COMMAND_HDR_SIZE];
+	}
+
+	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;
+
+	return skb_dequeue(&ath->txq);
+}
+
+/* Recv data */
+static int ath_recv(struct hci_uart *hu, void *data, int count)
+{
+	if (hci_recv_stream_fragment(hu->hdev, data, count) < 0)
+		BT_ERR("Frame Reassembly Failed");
+
+	return count;
+}
+
+static struct hci_uart_proto athp = {
+	.id = HCI_UART_ATH3K,
+	.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("HCIATH3K protocol initialized");
+	else
+		BT_ERR("HCIATH3K protocol registration failed");
+
+	return err;
+}
+
+int ath_deinit(void)
+{
+	return hci_uart_unregister_proto(&athp);
+}

drivers/bluetooth/hci_ldisc.c

···
 #ifdef CONFIG_BT_HCIUART_LL
 	ll_init();
 #endif
+#ifdef CONFIG_BT_HCIUART_ATH3K
+	ath_init();
+#endif
 
 	return 0;
 }
···
 #endif
 #ifdef CONFIG_BT_HCIUART_LL
 	ll_deinit();
+#endif
+#ifdef CONFIG_BT_HCIUART_ATH3K
+	ath_deinit();
 #endif
 
 	/* Release tty registration of line discipline */

drivers/bluetooth/hci_uart.h

···
 #define HCIUARTGETFLAGS		_IOR('U', 204, 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_ATH3K	5
 
 #define HCI_UART_RAW_DEVICE	0
 
···
 #ifdef CONFIG_BT_HCIUART_LL
 int ll_init(void);
 int ll_deinit(void);
+#endif
+
+#ifdef CONFIG_BT_HCIUART_ATH3K
+int ath_init(void);
+int ath_deinit(void);
 #endif