/* ------------------------------------------------------------------------- *//* i2c-algo-pcf.c i2c driver algorithms for PCF8584 adapters		     *//* ------------------------------------------------------------------------- *//*   Copyright (C) 1995-1997 Simon G. Vogl                   1998-2000 Hans Berglund    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., 675 Mass Ave, Cambridge, MA 02139, USA.		     *//* ------------------------------------------------------------------------- *//* With some changes from Ky鰏ti M鋖kki <kmalkki@cc.hut.fi> and    Frodo Looijaard <frodol@dds.nl> ,and also from Martin Bailey   <mbailey@littlefeet-inc.com> *//* Partially rewriten by Oleg I. Vdovikin <vdovikin@jscc.ru> to handle multiple   messages, proper stop/repstart signaling during receive,   added detect code */#include <linux/kernel.h>#include <linux/module.h>#include <linux/delay.h>#include <linux/slab.h>#include <linux/init.h>#include <linux/errno.h>#include <linux/i2c.h>#include <linux/i2c-algo-pcf.h>#include "i2c-algo-pcf.h"#define DEB2(x) if (i2c_debug>=2) x#define DEB3(x) if (i2c_debug>=3) x /* print several statistical values*/#define DEBPROTO(x) if (i2c_debug>=9) x; 	/* debug the protocol by showing transferred bits */#define DEF_TIMEOUT 16/* module parameters: */static int i2c_debug;/* --- setting states on the bus with the right timing: ---------------	*/#define set_pcf(adap, ctl, val) adap->setpcf(adap->data, ctl, val)#define get_pcf(adap, ctl) adap->getpcf(adap->data, ctl)#define get_own(adap) adap->getown(adap->data)#define get_clock(adap) adap->getclock(adap->data)#define i2c_outb(adap, val) adap->setpcf(adap->data, 0, val)#define i2c_inb(adap) adap->getpcf(adap->data, 0)/* --- other auxiliary functions --------------------------------------	*/static void i2c_start(struct i2c_algo_pcf_data *adap) {	DEBPROTO(printk("S "));	set_pcf(adap, 1, I2C_PCF_START);}static void i2c_repstart(struct i2c_algo_pcf_data *adap) {	DEBPROTO(printk(" Sr "));	set_pcf(adap, 1, I2C_PCF_REPSTART);}static void i2c_stop(struct i2c_algo_pcf_data *adap) {	DEBPROTO(printk("P\n"));	set_pcf(adap, 1, I2C_PCF_STOP);}static int wait_for_bb(struct i2c_algo_pcf_data *adap) {	int timeout = DEF_TIMEOUT;	int status;	status = get_pcf(adap, 1);#ifndef STUB_I2C	while (timeout-- && !(status & I2C_PCF_BB)) {		udelay(100); /* wait for 100 us */		status = get_pcf(adap, 1);	}#endif	if (timeout <= 0) {		printk(KERN_ERR "Timeout waiting for Bus Busy\n");	}		return (timeout<=0);}static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status) {	int timeout = DEF_TIMEOUT;	*status = get_pcf(adap, 1);#ifndef STUB_I2C	while (timeout-- && (*status & I2C_PCF_PIN)) {		adap->waitforpin();		*status = get_pcf(adap, 1);	}	if (*status & I2C_PCF_LAB) {		DEB2(printk(KERN_INFO 			"i2c-algo-pcf.o: lost arbitration (CSR 0x%02x)\n",			 *status));		/* Cleanup from LAB-- reset and enable ESO.		 * This resets the PCF8584; since we've lost the bus, no		 * further attempts should be made by callers to clean up 		 * (no i2c_stop() etc.)		 */		set_pcf(adap, 1, I2C_PCF_PIN);		set_pcf(adap, 1, I2C_PCF_ESO);		/* TODO: we should pause for a time period sufficient for any		 * running I2C transaction to complete-- the arbitration		 * logic won't work properly until the next START is seen.		 */		DEB2(printk(KERN_INFO 			"i2c-algo-pcf.o: reset LAB condition (CSR 0x%02x)\n", 			get_pcf(adap,1)));		return(-EINTR);	}#endif	if (timeout <= 0)		return(-1);	else		return(0);}/*  * This should perform the 'PCF8584 initialization sequence' as described * in the Philips IC12 data book (1995, Aug 29). * There should be a 30 clock cycle wait after reset, I assume this * has been fulfilled. * There should be a delay at the end equal to the longest I2C message * to synchronize the BB-bit (in multimaster systems). How long is * this? I assume 1 second is always long enough. * * vdovikin: added detect code for PCF8584 */static int pcf_init_8584 (struct i2c_algo_pcf_data *adap){	unsigned char temp;	DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: PCF state 0x%02x\n", get_pcf(adap, 1)));	/* S1=0x80: S0 selected, serial interface off */	set_pcf(adap, 1, I2C_PCF_PIN);	/* check to see S1 now used as R/W ctrl -	   PCF8584 does that when ESO is zero */	if (((temp = get_pcf(adap, 1)) & 0x7f) != (0)) {		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S0 (0x%02x).\n", temp));		return -ENXIO; /* definetly not PCF8584 */	}	/* load own address in S0, effective address is (own << 1)	*/	i2c_outb(adap, get_own(adap));	/* check it's really written */	if ((temp = i2c_inb(adap)) != get_own(adap)) {		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S0 (0x%02x).\n", temp));		return -ENXIO;	}	/* S1=0xA0, next byte in S2					*/	set_pcf(adap, 1, I2C_PCF_PIN | I2C_PCF_ES1);	/* check to see S2 now selected */	if (((temp = get_pcf(adap, 1)) & 0x7f) != I2C_PCF_ES1) {		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S2 (0x%02x).\n", temp));		return -ENXIO;	}	/* load clock register S2					*/	i2c_outb(adap, get_clock(adap));	/* check it's really written, the only 5 lowest bits does matter */	if (((temp = i2c_inb(adap)) & 0x1f) != get_clock(adap)) {		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S2 (0x%02x).\n", temp));		return -ENXIO;	}	/* Enable serial interface, idle, S0 selected			*/	set_pcf(adap, 1, I2C_PCF_IDLE);	/* check to see PCF is really idled and we can access status register */	if ((temp = get_pcf(adap, 1)) != (I2C_PCF_PIN | I2C_PCF_BB)) {		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S1` (0x%02x).\n", temp));		return -ENXIO;	}		printk(KERN_DEBUG "i2c-algo-pcf.o: deteted and initialized PCF8584.\n");	return 0;}/* ----- Utility functions */static inline int try_address(struct i2c_algo_pcf_data *adap,		       unsigned char addr, int retries){	int i, status, ret = -1;	int wfp;	for (i=0;i<retries;i++) {		i2c_outb(adap, addr);		i2c_start(adap);		status = get_pcf(adap, 1);		if ((wfp = wait_for_pin(adap, &status)) >= 0) {			if ((status & I2C_PCF_LRB) == 0) { 				i2c_stop(adap);				break;	/* success! */			}		}		if (wfp == -EINTR) {			/* arbitration lost */			udelay(adap->udelay);			return -EINTR;		}		i2c_stop(adap);		udelay(adap->udelay);	}	DEB2(if (i) printk(KERN_DEBUG "i2c-algo-pcf.o: needed %d retries for %d\n",i,	                   addr));	return ret;}static int pcf_sendbytes(struct i2c_adapter *i2c_adap, const char *buf,                         int count, int last){	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;	int wrcount, status, timeout;    	for (wrcount=0; wrcount<count; ++wrcount) {		DEB2(dev_dbg(&i2c_adap->dev, "i2c_write: writing %2.2X\n",				buf[wrcount]&0xff));		i2c_outb(adap, buf[wrcount]);		timeout = wait_for_pin(adap, &status);		if (timeout) {			if (timeout == -EINTR) {				/* arbitration lost */				return -EINTR;			}			i2c_stop(adap);			dev_err(&i2c_adap->dev, "i2c_write: error - timeout.\n");			return -EREMOTEIO; /* got a better one ?? */		}#ifndef STUB_I2C		if (status & I2C_PCF_LRB) {			i2c_stop(adap);			dev_err(&i2c_adap->dev, "i2c_write: error - no ack.\n");			return -EREMOTEIO; /* got a better one ?? */		}#endif	}	if (last) {		i2c_stop(adap);	}	else {		i2c_repstart(adap);	}	return (wrcount);}static int pcf_readbytes(struct i2c_adapter *i2c_adap, char *buf,                         int count, int last){	int i, status;	struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;	int wfp;	/* increment number of bytes to read by one -- read dummy byte */	for (i = 0; i <= count; i++) {		if ((wfp = wait_for_pin(adap, &status))) {			if (wfp == -EINTR) {				/* arbitration lost */				return -EINTR;			}			i2c_stop(adap);			dev_err(&i2c_adap->dev, "pcf_readbytes timed out.\n");			return (-1);		}#ifndef STUB_I2C		if ((status & I2C_PCF_LRB) && (i != count)) {			i2c_stop(adap);			dev_err(&i2c_adap->dev, "i2c_read: i2c_inb, No ack.\n");			return (-1);		}#endif				if (i == count - 1) {			set_pcf(adap, 1, I2C_PCF_ESO);		} else 		if (i == count) {			if (last) {				i2c_stop(adap);			} else {				i2c_repstart(adap);			}		};		if (i) {			buf[i - 1] = i2c_inb(adap);		} else {			i2c_inb(adap); /* dummy read */		}	}	return (i - 1);}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(KERN_DEBUG "addr0: %d\n",addr));		/* try extended address code...*/		ret = try_address(adap, addr, retries);		if (ret!=1) {			printk(KERN_ERR "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(KERN_ERR "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(KERN_ERR "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;	int ret=0, timeout, status;    	/* Check for bus busy */	timeout = wait_for_bb(adap);	if (timeout) {		DEB2(printk(KERN_ERR "i2c-algo-pcf.o: "		            "Timeout waiting for BB in pcf_xfer\n");)		return -EIO;	}		for (i = 0;ret >= 0 && i < num; i++) {		pmsg = &msgs[i];		DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: Doing %s %d bytes to 0x%02x - %d of %d messages\n",		     pmsg->flags & I2C_M_RD ? "read" : "write",                     pmsg->len, pmsg->addr, i + 1, num);)    		ret = pcf_doAddress(adap, pmsg, i2c_adap->retries);		/* Send START */		if (i == 0) {			i2c_start(adap); 		}    		/* Wait for PIN (pending interrupt NOT) */		timeout = wait_for_pin(adap, &status);		if (timeout) {			if (timeout == -EINTR) {				/* arbitration lost */				return (-EINTR);			}			i2c_stop(adap);			DEB2(printk(KERN_ERR "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(KERN_ERR "i2c-algo-pcf.o: No LRB(1) in pcf_xfer\n");)			return (-EREMOTEIO);		}#endif    		DEB3(printk(KERN_DEBUG "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,                                            (i + 1 == num));        			if (ret != pmsg->len) {				DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "					    "only read %d bytes.\n",ret));			} else {				DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: read %d bytes.\n",ret));			}		} else { /* Write */			ret = pcf_sendbytes(i2c_adap, pmsg->buf, pmsg->len,                                            (i + 1 == num));        			if (ret != pmsg->len) {				DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "					    "only wrote %d bytes.\n",ret));			} else {				DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: wrote %d bytes.\n",ret));			}		}	}	return (i);}static u32 pcf_func(struct i2c_adapter *adap){	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | 	       I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING; }/* -----exported algorithm data: -------------------------------------	*/static const struct i2c_algorithm pcf_algo = {	.master_xfer	= pcf_xfer,	.functionality	= pcf_func,};/*  * registering functions to load algorithms at runtime  */int i2c_pcf_add_bus(struct i2c_adapter *adap){	struct i2c_algo_pcf_data *pcf_adap = adap->algo_data;	int rval;	DEB2(dev_dbg(&adap->dev, "hw routines registered.\n"));	/* register new adapter to i2c module... */	adap->algo = &pcf_algo;	adap->timeout = 100;		/* default values, should	*/	adap->retries = 3;		/* be replaced by defines	*/	if ((rval = pcf_init_8584(pcf_adap)))		return rval;	rval = i2c_add_adapter(adap);	return rval;}int i2c_pcf_del_bus(struct i2c_adapter *adap){	return i2c_del_adapter(adap);}EXPORT_SYMBOL(i2c_pcf_add_bus);EXPORT_SYMBOL(i2c_pcf_del_bus);MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>");MODULE_DESCRIPTION("I2C-Bus PCF8584 algorithm");MODULE_LICENSE("GPL");module_param(i2c_debug, int, S_IRUGO | S_IWUSR);MODULE_PARM_DESC(i2c_debug,        "debug level - 0 off; 1 normal; 2,3 more verbose; 9 pcf-protocol");