i2c-algo-pcf.c

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			       "error - no ack.\n", i2c_adap->name);
			return -EREMOTEIO; /* got a better one ?? */
		}
#endif
	}
	i2c_stop(adap);
	return (wrcount);
}


static int pcf_readbytes(struct i2c_adapter *i2c_adap, char *buf, int count)
{
	int rdcount=0, i, status, timeout, dummy=1;
	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
    
	for (i=0; i<count; ++i) {
		buf[rdcount] = i2c_inb(adap);
		if (dummy) {
			dummy = 0;
		} else {
			rdcount++;
		}
		timeout = wait_for_pin(adap, &status);
		if (timeout) {
			i2c_stop(adap);
			printk("i2c-algo-pcf.o: i2c_read: "
			       "i2c_inb timed out.\n");
			return (-1);
		}
#ifndef STUB_I2C
		if (status & I2C_PCF_LRB) {
			i2c_stop(adap);
			printk("i2c-algo-pcf.o: i2c_read: i2c_inb, No ack.\n");
			return (-1);
		}
#endif
	}
	set_pcf(adap, 1, I2C_PCF_ESO);
	buf[rdcount] = i2c_inb(adap);
	if (dummy) {
		dummy = 0;
	} else {
		rdcount++;
	}
	timeout = wait_for_pin(adap, &status);
	if (timeout) {
		i2c_stop(adap);
		printk("i2c-algo-pcf.o: i2c_read: i2c_inb timed out.\n");
		return (-1);
	}
    
	i2c_stop(adap);

	/* Read final byte from S0 register */
	buf[rdcount++] = i2c_inb(adap);

	return (rdcount);
}


static inline int pcf_doAddress(struct i2c_algo_pcf_data *adap,
                                struct i2c_msg *msg, int retries) 
{
	unsigned short flags = msg->flags;
	unsigned char addr;
	int ret;
	if ( (flags & I2C_M_TEN)  ) { 
		/* a ten bit address */
		addr = 0xf0 | (( msg->addr >> 7) & 0x03);
		DEB2(printk("addr0: %d\n",addr));
		/* try extended address code...*/
		ret = try_address(adap, addr, retries);
		if (ret!=1) {
			printk("died at extended address code.\n");
			return -EREMOTEIO;
		}
		/* the remaining 8 bit address */
		i2c_outb(adap,msg->addr & 0x7f);
/* Status check comes here */
		if (ret != 1) {
			printk("died at 2nd address code.\n");
			return -EREMOTEIO;
		}
		if ( flags & I2C_M_RD ) {
			i2c_repstart(adap);
			/* okay, now switch into reading mode */
			addr |= 0x01;
			ret = try_address(adap, addr, retries);
			if (ret!=1) {
				printk("died at extended address code.\n");
				return -EREMOTEIO;
			}
		}
	} else {		/* normal 7bit address	*/
		addr = ( msg->addr << 1 );
		if (flags & I2C_M_RD )
			addr |= 1;
		if (flags & I2C_M_REV_DIR_ADDR )
			addr ^= 1;
		i2c_outb(adap, addr);
	}
	return 0;
}

static int pcf_xfer(struct i2c_adapter *i2c_adap,
		    struct i2c_msg msgs[], 
		    int num)
{
	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
	struct i2c_msg *pmsg;
	int i = 0;
	int ret, timeout, status;
    
	pmsg = &msgs[i];
    
	/* Send address here if Read */
	if (pmsg->flags & I2C_M_RD) {
		ret = pcf_doAddress(adap, pmsg, i2c_adap->retries);
	}
    
	/* Check for bus busy */
	timeout = wait_for_bb(adap);
	if (timeout) {
		DEB2(printk("i2c-algo-pcf.o: "
		            "Timeout waiting for BB in pcf_xfer\n");)
		return -EIO;
	}
    
	/* Send address here if Write */
	if (!(pmsg->flags & I2C_M_RD)) {
		ret = pcf_doAddress(adap, pmsg, i2c_adap->retries);
	}
	/* Send START */
	i2c_start(adap);
    
	/* Wait for PIN (pending interrupt NOT) */
	timeout = wait_for_pin(adap, &status);
	if (timeout) {
		i2c_stop(adap);
		DEB2(printk("i2c-algo-pcf.o: Timeout waiting "
		            "for PIN(1) in pcf_xfer\n");)
		return (-EREMOTEIO);
	}
    
#ifndef STUB_I2C
	/* Check LRB (last rcvd bit - slave ack) */
	if (status & I2C_PCF_LRB) {
		i2c_stop(adap);
		DEB2(printk("i2c-algo-pcf.o: No LRB(1) in pcf_xfer\n");)
		return (-EREMOTEIO);
	}
#endif
    
	DEB3(printk("i2c-algo-pcf.o: Msg %d, addr=0x%x, flags=0x%x, len=%d\n",
	            i, msgs[i].addr, msgs[i].flags, msgs[i].len);)
    
	/* Read */
	if (pmsg->flags & I2C_M_RD) {
        
		/* read bytes into buffer*/
		ret = pcf_readbytes(i2c_adap, pmsg->buf, pmsg->len);
        
		if (ret != pmsg->len) {
			DEB2(printk("i2c-algo-pcf.o: fail: "
			            "only read %d bytes.\n",ret));
		} else {
			DEB2(printk("i2c-algo-pcf.o: read %d bytes.\n",ret));
		}
	} else { /* Write */
        
        /* Write bytes from buffer */
		ret = pcf_sendbytes(i2c_adap, pmsg->buf, pmsg->len);
        
		if (ret != pmsg->len) {
			DEB2(printk("i2c-algo-pcf.o: fail: "
			            "only wrote %d bytes.\n",ret));
		} else {
			DEB2(printk("i2c-algo-pcf.o: wrote %d bytes.\n",ret));
		}
	}
	return (num);
}

static int algo_control(struct i2c_adapter *adapter, 
	unsigned int cmd, unsigned long arg)
{
	return 0;
}

static u32 pcf_func(struct i2c_adapter *adap)
{
	return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR | 
	       I2C_FUNC_PROTOCOL_MANGLING; 
}

/* -----exported algorithm data: -------------------------------------	*/

static struct i2c_algorithm pcf_algo = {
	"PCF8584 algorithm",
	I2C_ALGO_PCF,
	pcf_xfer,
	NULL,
	NULL,				/* slave_xmit		*/
	NULL,				/* slave_recv		*/
	algo_control,			/* ioctl		*/
	pcf_func,			/* functionality	*/
};

/* 
 * registering functions to load algorithms at runtime 
 */
int i2c_pcf_add_bus(struct i2c_adapter *adap)
{
	int i, status;
	struct i2c_algo_pcf_data *pcf_adap = adap->algo_data;

	if (pcf_test) {
		int ret = test_bus(pcf_adap, adap->name);
		if (ret<0)
			return -ENODEV;
	}

	DEB2(printk("i2c-algo-pcf.o: hw routines for %s registered.\n",
	            adap->name));

	/* register new adapter to i2c module... */

	adap->id |= pcf_algo.id;
	adap->algo = &pcf_algo;

	adap->timeout = 100;	/* default values, should	*/
	adap->retries = 3;		/* be replaced by defines	*/

#ifdef MODULE
	MOD_INC_USE_COUNT;
#endif

	i2c_add_adapter(adap);
	pcf_init_8584(pcf_adap);

	/* scan bus */
	if (pcf_scan) {
		printk(KERN_INFO " i2c-algo-pcf.o: scanning bus %s.\n",
		       adap->name);
		for (i = 0x00; i < 0xff; i+=2) {
			i2c_outb(pcf_adap, i);
			i2c_start(pcf_adap);
			if ((wait_for_pin(pcf_adap, &status) >= 0) && 
			    ((status & I2C_PCF_LRB) == 0)) { 
				printk("(%02x)",i>>1); 
			} else {
				printk("."); 
			}
			i2c_stop(pcf_adap);
			udelay(pcf_adap->udelay);
		}
		printk("\n");
	}
	return 0;
}


int i2c_pcf_del_bus(struct i2c_adapter *adap)
{
	int res;
	if ((res = i2c_del_adapter(adap)) < 0)
		return res;
	DEB2(printk("i2c-algo-pcf.o: adapter unregistered: %s\n",adap->name));

#ifdef MODULE
	MOD_DEC_USE_COUNT;
#endif
	return 0;
}

int __init i2c_algo_pcf_init (void)
{
	printk("i2c-algo-pcf.o: i2c pcf8584 algorithm module\n");
	return 0;
}


EXPORT_SYMBOL(i2c_pcf_add_bus);
EXPORT_SYMBOL(i2c_pcf_del_bus);

#ifdef MODULE
MODULE_AUTHOR("Hans Berglund <[e-mail]>");
MODULE_DESCRIPTION("I2C-Bus PCF8584 algorithm");

MODULE_PARM(pcf_test, "i");
MODULE_PARM(pcf_scan, "i");
MODULE_PARM(i2c_debug,"i");

MODULE_PARM_DESC(pcf_test, "Test if the I2C bus is available");
MODULE_PARM_DESC(pcf_scan, "Scan for active chips on the bus");
MODULE_PARM_DESC(i2c_debug,
        "debug level - 0 off; 1 normal; 2,3 more verbose; 9 pcf-protocol");


int init_module(void) 
{
	return i2c_algo_pcf_init();
}

void cleanup_module(void) 
{
}
#endif