btuart.c

基于arm的蓝牙通讯协议的设计

/*
 *
 *  Driver for Bluetooth PCMCIA cards with HCI UART interface
 *
 *
 */

#include <linux/config.h>
#include <linux/module.h>

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/spinlock.h>

#include <linux/skbuff.h>
#include <linux/string.h>
#include <linux/serial.h>
#include <linux/serial_reg.h>
#include <asm/system.h>
#include <asm/bitops.h>
#include <asm/io.h>

#include <pcmcia/version.h>
#include <pcmcia/cs_types.h>
#include <pcmcia/cs.h>
#include <pcmcia/cistpl.h>
#include <pcmcia/ciscode.h>
#include <pcmcia/ds.h>
#include <pcmcia/cisreg.h>

#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>



/* ======================== Module parameters ======================== */


/* Bit map of interrupts to choose from */
static u_int irq_mask = 0xffff;
static int irq_list[4] = { -1 };

MODULE_PARM(irq_mask, "i");
MODULE_PARM(irq_list, "1-4i");

MODULE_AUTHOR("Marcel Holtmann <[e-mail]>");
MODULE_DESCRIPTION("BlueZ driver for Bluetooth PCMCIA cards with HCI UART interface");
MODULE_LICENSE("GPL");



/* ======================== Local structures ======================== */


typedef struct btuart_info_t {
	dev_link_t link;
	dev_node_t node;

	struct hci_dev hdev;

	spinlock_t lock;	/* For serializing operations */

	struct sk_buff_head txq;
	unsigned long tx_state;

	unsigned long rx_state;
	unsigned long rx_count;
	struct sk_buff *rx_skb;
} btuart_info_t;


void btuart_config(dev_link_t *link);
void btuart_release(u_long arg);
int btuart_event(event_t event, int priority, event_callback_args_t *args);

static dev_info_t dev_info = "btuart_cs";

dev_link_t *btuart_attach(void);
void btuart_detach(dev_link_t *);

static dev_link_t *dev_list = NULL;


/* Maximum baud rate */
#define SPEED_MAX  115200

/* Default baud rate: 57600, 115200, 230400 or 460800 */
#define DEFAULT_BAUD_RATE  115200


/* Transmit states  */
#define XMIT_SENDING	1
#define XMIT_WAKEUP	2
#define XMIT_WAITING	8

/* Receiver states */
#define RECV_WAIT_PACKET_TYPE	0
#define RECV_WAIT_EVENT_HEADER	1
#define RECV_WAIT_ACL_HEADER	2
#define RECV_WAIT_SCO_HEADER	3
#define RECV_WAIT_DATA		4



/* ======================== Interrupt handling ======================== */


static int btuart_write(unsigned int iobase, int fifo_size, __u8 *buf, int len)
{
	int actual = 0;

	/* Tx FIFO should be empty */
	if (!(inb(iobase + UART_LSR) & UART_LSR_THRE))
		return 0;

	/* Fill FIFO with current frame */
	while ((fifo_size-- > 0) && (actual < len)) {
		/* Transmit next byte */
		outb(buf[actual], iobase + UART_TX);
		actual++;
	}

	return actual;
}


static void btuart_write_wakeup(btuart_info_t *info)
{
	if (!info) {
		printk(KERN_WARNING "btuart_cs: Call of write_wakeup for unknown device.\n");
		return;
	}

	if (test_and_set_bit(XMIT_SENDING, &(info->tx_state))) {
		set_bit(XMIT_WAKEUP, &(info->tx_state));
		return;
	}

	do {
		register unsigned int iobase = info->link.io.BasePort1;
		register struct sk_buff *skb;
		register int len;

		clear_bit(XMIT_WAKEUP, &(info->tx_state));

		if (!(info->link.state & DEV_PRESENT))
			return;

		if (!(skb = skb_dequeue(&(info->txq))))
			break;

		/* Send frame */
		len = btuart_write(iobase, 16, skb->data, skb->len);
		set_bit(XMIT_WAKEUP, &(info->tx_state));

		if (len == skb->len) {
			kfree_skb(skb);
		} else {
			skb_pull(skb, len);
			skb_queue_head(&(info->txq), skb);
		}

		info->hdev.stat.byte_tx += len;

	} while (test_bit(XMIT_WAKEUP, &(info->tx_state)));

	clear_bit(XMIT_SENDING, &(info->tx_state));
}


static void btuart_receive(btuart_info_t *info)
{
	unsigned int iobase;
	int boguscount = 0;

	if (!info) {
		printk(KERN_WARNING "btuart_cs: Call of receive for unknown device.\n");
		return;
	}

	iobase = info->link.io.BasePort1;

	do {
		info->hdev.stat.byte_rx++;

		/* Allocate packet */
		if (info->rx_skb == NULL) {
			info->rx_state = RECV_WAIT_PACKET_TYPE;
			info->rx_count = 0;
			if (!(info->rx_skb = bluez_skb_alloc(HCI_MAX_FRAME_SIZE, GFP_ATOMIC))) {
				printk(KERN_WARNING "btuart_cs: Can't allocate mem for new packet.\n");
				return;
			}
		}

		if (info->rx_state == RECV_WAIT_PACKET_TYPE) {

			info->rx_skb->dev = (void *)&(info->hdev);
			info->rx_skb->pkt_type = inb(iobase + UART_RX);

			switch (info->rx_skb->pkt_type) {

			case HCI_EVENT_PKT:
				info->rx_state = RECV_WAIT_EVENT_HEADER;
				info->rx_count = HCI_EVENT_HDR_SIZE;
				break;

			case HCI_ACLDATA_PKT:
				info->rx_state = RECV_WAIT_ACL_HEADER;
				info->rx_count = HCI_ACL_HDR_SIZE;
				break;

			case HCI_SCODATA_PKT:
				info->rx_state = RECV_WAIT_SCO_HEADER;
				info->rx_count = HCI_SCO_HDR_SIZE;
				break;

			default:
				/* Unknown packet */
				printk(KERN_WARNING "btuart_cs: Unknown HCI packet with type 0x%02x received.\n", info->rx_skb->pkt_type);
				info->hdev.stat.err_rx++;
				clear_bit(HCI_RUNNING, &(info->hdev.flags));

				kfree_skb(info->rx_skb);
				info->rx_skb = NULL;
				break;

			}

		} else {

			*skb_put(info->rx_skb, 1) = inb(iobase + UART_RX);
			info->rx_count--;

			if (info->rx_count == 0) {

				int dlen;
				hci_event_hdr *eh;
				hci_acl_hdr *ah;
				hci_sco_hdr *sh;


				switch (info->rx_state) {

				case RECV_WAIT_EVENT_HEADER:
					eh = (hci_event_hdr *)(info->rx_skb->data);
					info->rx_state = RECV_WAIT_DATA;
					info->rx_count = eh->plen;
					break;

				case RECV_WAIT_ACL_HEADER:
					ah = (hci_acl_hdr *)(info->rx_skb->data);
					dlen = __le16_to_cpu(ah->dlen);
					info->rx_state = RECV_WAIT_DATA;
					info->rx_count = dlen;
					break;

				case RECV_WAIT_SCO_HEADER:
					sh = (hci_sco_hdr *)(info->rx_skb->data);
					info->rx_state = RECV_WAIT_DATA;
					info->rx_count = sh->dlen;
					break;

				case RECV_WAIT_DATA:
					hci_recv_frame(info->rx_skb);
					info->rx_skb = NULL;
					break;

				}

			}

		}

		/* Make sure we don't stay here to long */
		if (boguscount++ > 16)
			break;

	} while (inb(iobase + UART_LSR) & UART_LSR_DR);
}


void btuart_interrupt(int irq, void *dev_inst, struct pt_regs *regs)
{
	btuart_info_t *info = dev_inst;
	unsigned int iobase;
	int boguscount = 0;
	int iir, lsr;

	if (!info) {
		printk(KERN_WARNING "btuart_cs: Call of irq %d for unknown device.\n", irq);
		return;
	}

	iobase = info->link.io.BasePort1;

	spin_lock(&(info->lock));

	iir = inb(iobase + UART_IIR) & UART_IIR_ID;
	while (iir) {

		/* Clear interrupt */
		lsr = inb(iobase + UART_LSR);

		switch (iir) {
		case UART_IIR_RLSI:
			printk(KERN_NOTICE "btuart_cs: RLSI\n");
			break;
		case UART_IIR_RDI:
			/* Receive interrupt */
			btuart_receive(info);
			break;
		case UART_IIR_THRI:
			if (lsr & UART_LSR_THRE) {
				/* Transmitter ready for data */
				btuart_write_wakeup(info);
			}
			break;
		default:
			printk(KERN_NOTICE "btuart_cs: Unhandled IIR=%#x\n", iir);
			break;
		}

		/* Make sure we don't stay here to long */
		if (boguscount++ > 100)
			break;

		iir = inb(iobase + UART_IIR) & UART_IIR_ID;

	}

	spin_unlock(&(info->lock));
}


static void btuart_change_speed(btuart_info_t *info, unsigned int speed)
{
	unsigned long flags;
	unsigned int iobase;
	int fcr;		/* FIFO control reg */
	int lcr;		/* Line control reg */
	int divisor;

	if (!info) {
		printk(KERN_WARNING "btuart_cs: Call of change speed for unknown device.\n");
		return;
	}

	iobase = info->link.io.BasePort1;

	spin_lock_irqsave(&(info->lock), flags);

	/* Turn off interrupts */
	outb(0, iobase + UART_IER);

	divisor = SPEED_MAX / speed;

	fcr = UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT;

	/* 
	 * Use trigger level 1 to avoid 3 ms. timeout delay at 9600 bps, and
	 * almost 1,7 ms at 19200 bps. At speeds above that we can just forget
	 * about this timeout since it will always be fast enough. 
	 */

	if (speed < 38400)
		fcr |= UART_FCR_TRIGGER_1;
	else
		fcr |= UART_FCR_TRIGGER_14;

	/* Bluetooth cards use 8N1 */
	lcr = UART_LCR_WLEN8;

	outb(UART_LCR_DLAB | lcr, iobase + UART_LCR);	/* Set DLAB */
	outb(divisor & 0xff, iobase + UART_DLL);	/* Set speed */
	outb(divisor >> 8, iobase + UART_DLM);
	outb(lcr, iobase + UART_LCR);	/* Set 8N1  */
	outb(fcr, iobase + UART_FCR);	/* Enable FIFO's */

	/* Turn on interrups */
	outb(UART_IER_RLSI | UART_IER_RDI | UART_IER_THRI, iobase + UART_IER);

	spin_unlock_irqrestore(&(info->lock), flags);
}



/* ======================== HCI interface ======================== */


static int btuart_hci_flush(struct hci_dev *hdev)
{
	btuart_info_t *info = (btuart_info_t *)(hdev->driver_data);

	/* Drop TX queue */
	skb_queue_purge(&(info->txq));

	return 0;
}


static int btuart_hci_open(struct hci_dev *hdev)
{
	set_bit(HCI_RUNNING, &(hdev->flags));

	return 0;
}


static int btuart_hci_close(struct hci_dev *hdev)
{
	if (!test_and_clear_bit(HCI_RUNNING, &(hdev->flags)))
		return 0;

	btuart_hci_flush(hdev);

	return 0;
}


static int btuart_hci_send_frame(struct sk_buff *skb)
{
	btuart_info_t *info;
	struct hci_dev *hdev = (struct hci_dev *)(skb->dev);

	if (!hdev) {
		printk(KERN_WARNING "btuart_cs: Frame for unknown HCI device (hdev=NULL).");
		return -ENODEV;
	}

	info = (btuart_info_t *)(hdev->driver_data);

	switch (skb->pkt_type) {
	case HCI_COMMAND_PKT:
		hdev->stat.cmd_tx++;
		break;
	case HCI_ACLDATA_PKT:
		hdev->stat.acl_tx++;
		break;
	case HCI_SCODATA_PKT:
		hdev->stat.sco_tx++;