diff options
| author | Wim Van Sebroeck <wim@iguana.be> | 2007-05-11 19:03:13 +0000 | 
|---|---|---|
| committer | Wim Van Sebroeck <wim@iguana.be> | 2007-05-11 19:03:13 +0000 | 
| commit | 5c34202b8bf942da411b6599668a76b07449bbfd (patch) | |
| tree | 5719c361321eaddc8e4f1b0c8a7994f0e9a6fdd3 /drivers/i2c/algos/i2c-algo-bit.c | |
| parent | 0d4804b31f91cfbcff6d62af0bc09a893a1c8ae0 (diff) | |
| parent | 1f8a6b658a943b4f04a1fc7b3a420360202c86cd (diff) | |
Merge /pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'drivers/i2c/algos/i2c-algo-bit.c')
| -rw-r--r-- | drivers/i2c/algos/i2c-algo-bit.c | 286 | 
1 files changed, 168 insertions, 118 deletions
diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c index 95aa5395a5b..8a5f5825bb7 100644 --- a/drivers/i2c/algos/i2c-algo-bit.c +++ b/drivers/i2c/algos/i2c-algo-bit.c @@ -33,19 +33,30 @@  /* ----- global defines ----------------------------------------------- */ -#define DEB(x) if (i2c_debug>=1) x; -#define DEB2(x) if (i2c_debug>=2) x; -#define DEBSTAT(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 */ +#ifdef DEBUG +#define bit_dbg(level, dev, format, args...) \ +	do { \ +		if (i2c_debug >= level) \ +			dev_dbg(dev, format, ##args); \ +	} while (0) +#else +#define bit_dbg(level, dev, format, args...) \ +	do {} while (0) +#endif /* DEBUG */  /* ----- global variables ---------------------------------------------	*/ -/* module parameters: - */ -static int i2c_debug;  static int bit_test;	/* see if the line-setting functions work	*/ +module_param(bit_test, bool, 0); +MODULE_PARM_DESC(bit_test, "Test the lines of the bus to see if it is stuck"); + +#ifdef DEBUG +static int i2c_debug = 1; +module_param(i2c_debug, int, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(i2c_debug, +		 "debug level - 0 off; 1 normal; 2 verbose; 3 very verbose"); +#endif  /* --- setting states on the bus with the right timing: ---------------	*/ @@ -57,19 +68,19 @@ static int bit_test;	/* see if the line-setting functions work	*/  static inline void sdalo(struct i2c_algo_bit_data *adap)  {  	setsda(adap,0); -	udelay(adap->udelay); +	udelay((adap->udelay + 1) / 2);  }  static inline void sdahi(struct i2c_algo_bit_data *adap)  {  	setsda(adap,1); -	udelay(adap->udelay); +	udelay((adap->udelay + 1) / 2);  }  static inline void scllo(struct i2c_algo_bit_data *adap)  {  	setscl(adap,0); -	udelay(adap->udelay); +	udelay(adap->udelay / 2);  }  /* @@ -98,7 +109,11 @@ static int sclhi(struct i2c_algo_bit_data *adap)  		}  		cond_resched();  	} -	DEBSTAT(printk(KERN_DEBUG "needed %ld jiffies\n", jiffies-start)); +#ifdef DEBUG +	if (jiffies != start && i2c_debug >= 3) +		pr_debug("i2c-algo-bit: needed %ld jiffies for SCL to go " +			 "high\n", jiffies - start); +#endif  done:  	udelay(adap->udelay); @@ -110,30 +125,29 @@ done:  static void i2c_start(struct i2c_algo_bit_data *adap)   {  	/* assert: scl, sda are high */ -	DEBPROTO(printk("S ")); -	sdalo(adap); +	setsda(adap, 0); +	udelay(adap->udelay);  	scllo(adap);  }  static void i2c_repstart(struct i2c_algo_bit_data *adap)   { -	/* scl, sda may not be high */ -	DEBPROTO(printk(" Sr ")); -	setsda(adap,1); +	/* assert: scl is low */ +	sdahi(adap);  	sclhi(adap); -	 -	sdalo(adap); +	setsda(adap, 0); +	udelay(adap->udelay);  	scllo(adap);  }  static void i2c_stop(struct i2c_algo_bit_data *adap)   { -	DEBPROTO(printk("P\n"));  	/* assert: scl is low */  	sdalo(adap);  	sclhi(adap);  -	sdahi(adap); +	setsda(adap, 1); +	udelay(adap->udelay);  } @@ -145,7 +159,7 @@ static void i2c_stop(struct i2c_algo_bit_data *adap)   * 0 if the device did not ack   * -ETIMEDOUT if an error occurred (while raising the scl line)   */ -static int i2c_outb(struct i2c_adapter *i2c_adap, char c) +static int i2c_outb(struct i2c_adapter *i2c_adap, unsigned char c)  {  	int i;  	int sb; @@ -154,34 +168,32 @@ static int i2c_outb(struct i2c_adapter *i2c_adap, char c)  	/* assert: scl is low */  	for ( i=7 ; i>=0 ; i-- ) { -		sb = c & ( 1 << i ); +		sb = (c >> i) & 1;  		setsda(adap,sb); -		udelay(adap->udelay); -		DEBPROTO(printk(KERN_DEBUG "%d",sb!=0)); +		udelay((adap->udelay + 1) / 2);  		if (sclhi(adap)<0) { /* timed out */ -			sdahi(adap); /* we don't want to block the net */ -			DEB2(printk(KERN_DEBUG " i2c_outb: 0x%02x, timeout at bit #%d\n", c&0xff, i)); +			bit_dbg(1, &i2c_adap->dev, "i2c_outb: 0x%02x, " +				"timeout at bit #%d\n", (int)c, i);  			return -ETIMEDOUT;  		};  		/* do arbitration here:   		 * if ( sb && ! getsda(adap) ) -> ouch! Get out of here.  		 */ -		setscl(adap, 0 ); -		udelay(adap->udelay); +		scllo(adap);  	}  	sdahi(adap);  	if (sclhi(adap)<0){ /* timeout */ -	    DEB2(printk(KERN_DEBUG " i2c_outb: 0x%02x, timeout at ack\n", c&0xff)); -	    return -ETIMEDOUT; +		bit_dbg(1, &i2c_adap->dev, "i2c_outb: 0x%02x, " +			"timeout at ack\n", (int)c); +		return -ETIMEDOUT;  	};  	/* read ack: SDA should be pulled down by slave */ -	ack=getsda(adap);	/* ack: sda is pulled low ->success.	 */ -	DEB2(printk(KERN_DEBUG " i2c_outb: 0x%02x , getsda() = %d\n", c & 0xff, ack)); +	ack = !getsda(adap);    /* ack: sda is pulled low -> success */ +	bit_dbg(2, &i2c_adap->dev, "i2c_outb: 0x%02x %s\n", (int)c, +		ack ? "A" : "NA"); -	DEBPROTO( printk(KERN_DEBUG "[%2.2x]",c&0xff) ); -	DEBPROTO(if (0==ack){ printk(KERN_DEBUG " A ");} else printk(KERN_DEBUG " NA ") );  	scllo(adap); -	return 0==ack;		/* return 1 if device acked	 */ +	return ack;  	/* assert: scl is low (sda undef) */  } @@ -198,19 +210,18 @@ static int i2c_inb(struct i2c_adapter *i2c_adap)  	sdahi(adap);  	for (i=0;i<8;i++) {  		if (sclhi(adap)<0) { /* timeout */ -			DEB2(printk(KERN_DEBUG " i2c_inb: timeout at bit #%d\n", 7-i)); +			bit_dbg(1, &i2c_adap->dev, "i2c_inb: timeout at bit " +				"#%d\n", 7 - i);  			return -ETIMEDOUT;  		};  		indata *= 2;  		if ( getsda(adap) )   			indata |= 0x01; -		scllo(adap); +		setscl(adap, 0); +		udelay(i == 7 ? adap->udelay / 2 : adap->udelay);  	}  	/* assert: scl is low */ -	DEB2(printk(KERN_DEBUG "i2c_inb: 0x%02x\n", indata & 0xff)); - -	DEBPROTO(printk(KERN_DEBUG " 0x%02x", indata & 0xff)); -	return (int) (indata & 0xff); +	return indata;  }  /* @@ -221,73 +232,67 @@ static int test_bus(struct i2c_algo_bit_data *adap, char* name) {  	int scl,sda;  	if (adap->getscl==NULL) -		printk(KERN_INFO "i2c-algo-bit.o: Testing SDA only, " -			"SCL is not readable.\n"); +		pr_info("%s: Testing SDA only, SCL is not readable\n", name);  	sda=getsda(adap);  	scl=(adap->getscl==NULL?1:getscl(adap)); -	printk(KERN_DEBUG "i2c-algo-bit.o: (0) scl=%d, sda=%d\n",scl,sda);  	if (!scl || !sda ) { -		printk(KERN_WARNING "i2c-algo-bit.o: %s seems to be busy.\n", name); +		printk(KERN_WARNING "%s: bus seems to be busy\n", name);  		goto bailout;  	}  	sdalo(adap);  	sda=getsda(adap);  	scl=(adap->getscl==NULL?1:getscl(adap)); -	printk(KERN_DEBUG "i2c-algo-bit.o: (1) scl=%d, sda=%d\n",scl,sda);  	if ( 0 != sda ) { -		printk(KERN_WARNING "i2c-algo-bit.o: SDA stuck high!\n"); +		printk(KERN_WARNING "%s: SDA stuck high!\n", name);  		goto bailout;  	}  	if ( 0 == scl ) { -		printk(KERN_WARNING "i2c-algo-bit.o: SCL unexpected low " -			"while pulling SDA low!\n"); +		printk(KERN_WARNING "%s: SCL unexpected low " +		       "while pulling SDA low!\n", name);  		goto bailout;  	}		  	sdahi(adap);  	sda=getsda(adap);  	scl=(adap->getscl==NULL?1:getscl(adap)); -	printk(KERN_DEBUG "i2c-algo-bit.o: (2) scl=%d, sda=%d\n",scl,sda);  	if ( 0 == sda ) { -		printk(KERN_WARNING "i2c-algo-bit.o: SDA stuck low!\n"); +		printk(KERN_WARNING "%s: SDA stuck low!\n", name);  		goto bailout;  	}  	if ( 0 == scl ) { -		printk(KERN_WARNING "i2c-algo-bit.o: SCL unexpected low " -			"while pulling SDA high!\n"); +		printk(KERN_WARNING "%s: SCL unexpected low " +		       "while pulling SDA high!\n", name);  		goto bailout;  	}  	scllo(adap);  	sda=getsda(adap);  	scl=(adap->getscl==NULL?0:getscl(adap)); -	printk(KERN_DEBUG "i2c-algo-bit.o: (3) scl=%d, sda=%d\n",scl,sda);  	if ( 0 != scl ) { -		printk(KERN_WARNING "i2c-algo-bit.o: SCL stuck high!\n"); +		printk(KERN_WARNING "%s: SCL stuck high!\n", name);  		goto bailout;  	}  	if ( 0 == sda ) { -		printk(KERN_WARNING "i2c-algo-bit.o: SDA unexpected low " -			"while pulling SCL low!\n"); +		printk(KERN_WARNING "%s: SDA unexpected low " +		       "while pulling SCL low!\n", name);  		goto bailout;  	}  	sclhi(adap);  	sda=getsda(adap);  	scl=(adap->getscl==NULL?1:getscl(adap)); -	printk(KERN_DEBUG "i2c-algo-bit.o: (4) scl=%d, sda=%d\n",scl,sda);  	if ( 0 == scl ) { -		printk(KERN_WARNING "i2c-algo-bit.o: SCL stuck low!\n"); +		printk(KERN_WARNING "%s: SCL stuck low!\n", name);  		goto bailout;  	}  	if ( 0 == sda ) { -		printk(KERN_WARNING "i2c-algo-bit.o: SDA unexpected low " -			"while pulling SCL high!\n"); +		printk(KERN_WARNING "%s: SDA unexpected low " +		       "while pulling SCL high!\n", name);  		goto bailout;  	} -	printk(KERN_INFO "i2c-algo-bit.o: %s passed test.\n",name); +	pr_info("%s: Test OK\n", name);  	return 0;  bailout:  	sdahi(adap); @@ -312,44 +317,39 @@ static int try_address(struct i2c_adapter *i2c_adap,  	int i,ret = -1;  	for (i=0;i<=retries;i++) {  		ret = i2c_outb(i2c_adap,addr); -		if (ret==1) -			break;	/* success! */ -		i2c_stop(adap); -		udelay(5/*adap->udelay*/); -		if (i==retries)  /* no success */ +		if (ret == 1 || i == retries)  			break; -		i2c_start(adap); +		bit_dbg(3, &i2c_adap->dev, "emitting stop condition\n"); +		i2c_stop(adap);  		udelay(adap->udelay); +		yield(); +		bit_dbg(3, &i2c_adap->dev, "emitting start condition\n"); +		i2c_start(adap);  	} -	DEB2(if (i) -	     printk(KERN_DEBUG "i2c-algo-bit.o: Used %d tries to %s client at 0x%02x : %s\n", -		    i+1, addr & 1 ? "read" : "write", addr>>1, -		    ret==1 ? "success" : ret==0 ? "no ack" : "failed, timeout?" ) -	    ); +	if (i && ret) +		bit_dbg(1, &i2c_adap->dev, "Used %d tries to %s client at " +			"0x%02x: %s\n", i + 1, +			addr & 1 ? "read from" : "write to", addr >> 1, +			ret == 1 ? "success" : "failed, timeout?");  	return ret;  }  static int sendbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg)  { -	struct i2c_algo_bit_data *adap = i2c_adap->algo_data; -	char c; -	const char *temp = msg->buf; +	const unsigned char *temp = msg->buf;  	int count = msg->len;  	unsigned short nak_ok = msg->flags & I2C_M_IGNORE_NAK;   	int retval;  	int wrcount=0;  	while (count > 0) { -		c = *temp; -		DEB2(dev_dbg(&i2c_adap->dev, "sendbytes: writing %2.2X\n", c&0xff)); -		retval = i2c_outb(i2c_adap,c); +		retval = i2c_outb(i2c_adap, *temp);  		if ((retval>0) || (nak_ok && (retval==0)))  { /* ok or ignored NAK */  			count--;   			temp++;  			wrcount++;  		} else { /* arbitration or no acknowledge */  			dev_err(&i2c_adap->dev, "sendbytes: error - bailout.\n"); -			i2c_stop(adap);  			return (retval<0)? retval : -EFAULT;  			        /* got a better one ?? */  		} @@ -362,7 +362,7 @@ static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg)  	int inval;  	int rdcount=0;   	/* counts bytes read */  	struct i2c_algo_bit_data *adap = i2c_adap->algo_data; -	char *temp = msg->buf; +	unsigned char *temp = msg->buf;  	int count = msg->len;  	while (count > 0) { @@ -371,30 +371,44 @@ static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg)  			*temp = inval;  			rdcount++;  		} else {   /* read timed out */ -			printk(KERN_ERR "i2c-algo-bit.o: readbytes: i2c_inb timed out.\n");  			break;  		}  		temp++;  		count--; -		if (msg->flags & I2C_M_NO_RD_ACK) +		if (msg->flags & I2C_M_NO_RD_ACK) { +			bit_dbg(2, &i2c_adap->dev, "i2c_inb: 0x%02x\n", +				inval);  			continue; - -		if ( count > 0 ) {		/* send ack */ -			sdalo(adap); -			DEBPROTO(printk(" Am ")); -		} else { -			sdahi(adap);	/* neg. ack on last byte */ -			DEBPROTO(printk(" NAm "));  		} + +		/* assert: sda is high */ +		if (count)		/* send ack */ +			setsda(adap, 0); +		udelay((adap->udelay + 1) / 2); +		bit_dbg(2, &i2c_adap->dev, "i2c_inb: 0x%02x %s\n", inval, +			count ? "A" : "NA");  		if (sclhi(adap)<0) {	/* timeout */ -			sdahi(adap); -			printk(KERN_ERR "i2c-algo-bit.o: readbytes: Timeout at ack\n"); +			dev_err(&i2c_adap->dev, "readbytes: timeout at ack\n");  			return -ETIMEDOUT;  		};  		scllo(adap); -		sdahi(adap); + +		/* Some SMBus transactions require that we receive the +		   transaction length as the first read byte. */ +		if (rdcount == 1 && (msg->flags & I2C_M_RECV_LEN)) { +			if (inval <= 0 || inval > I2C_SMBUS_BLOCK_MAX) { +				dev_err(&i2c_adap->dev, "readbytes: invalid " +					"block length (%d)\n", inval); +				return -EREMOTEIO; +			} +			/* The original count value accounts for the extra +			   bytes, that is, either 1 for a regular transaction, +			   or 2 for a PEC transaction. */ +			count += inval; +			msg->len += inval; +		}  	}  	return rdcount;  } @@ -421,27 +435,31 @@ static int bit_doAddress(struct i2c_adapter *i2c_adap, struct i2c_msg *msg)  	if ( (flags & I2C_M_TEN)  ) {   		/* a ten bit address */  		addr = 0xf0 | (( msg->addr >> 7) & 0x03); -		DEB2(printk(KERN_DEBUG "addr0: %d\n",addr)); +		bit_dbg(2, &i2c_adap->dev, "addr0: %d\n", addr);  		/* try extended address code...*/  		ret = try_address(i2c_adap, addr, retries);  		if ((ret != 1) && !nak_ok)  { -			printk(KERN_ERR "died at extended address code.\n"); +			dev_err(&i2c_adap->dev, +				"died at extended address code\n");  			return -EREMOTEIO;  		}  		/* the remaining 8 bit address */  		ret = i2c_outb(i2c_adap,msg->addr & 0x7f);  		if ((ret != 1) && !nak_ok) {  			/* the chip did not ack / xmission error occurred */ -			printk(KERN_ERR "died at 2nd address code.\n"); +			dev_err(&i2c_adap->dev, "died at 2nd address code\n");  			return -EREMOTEIO;  		}  		if ( flags & I2C_M_RD ) { +			bit_dbg(3, &i2c_adap->dev, "emitting repeated " +				"start condition\n");  			i2c_repstart(adap);  			/* okay, now switch into reading mode */  			addr |= 0x01;  			ret = try_address(i2c_adap, addr, retries);  			if ((ret!=1) && !nak_ok) { -				printk(KERN_ERR "died at extended address code.\n"); +				dev_err(&i2c_adap->dev, +					"died at repeated address code\n");  				return -EREMOTEIO;  			}  		} @@ -468,44 +486,62 @@ static int bit_xfer(struct i2c_adapter *i2c_adap,  	int i,ret;  	unsigned short nak_ok; +	bit_dbg(3, &i2c_adap->dev, "emitting start condition\n");  	i2c_start(adap);  	for (i=0;i<num;i++) {  		pmsg = &msgs[i];  		nak_ok = pmsg->flags & I2C_M_IGNORE_NAK;   		if (!(pmsg->flags & I2C_M_NOSTART)) {  			if (i) { +				bit_dbg(3, &i2c_adap->dev, "emitting " +					"repeated start condition\n");  				i2c_repstart(adap);  			}  			ret = bit_doAddress(i2c_adap, pmsg);  			if ((ret != 0) && !nak_ok) { -			    DEB2(printk(KERN_DEBUG "i2c-algo-bit.o: NAK from device addr %2.2x msg #%d\n" -					,msgs[i].addr,i)); -			    return (ret<0) ? ret : -EREMOTEIO; +				bit_dbg(1, &i2c_adap->dev, "NAK from " +					"device addr 0x%02x msg #%d\n", +					msgs[i].addr, i); +				goto bailout;  			}  		}  		if (pmsg->flags & I2C_M_RD ) {  			/* read bytes into buffer*/  			ret = readbytes(i2c_adap, pmsg); -			DEB2(printk(KERN_DEBUG "i2c-algo-bit.o: read %d bytes.\n",ret)); -			if (ret < pmsg->len ) { -				return (ret<0)? ret : -EREMOTEIO; +			if (ret >= 1) +				bit_dbg(2, &i2c_adap->dev, "read %d byte%s\n", +					ret, ret == 1 ? "" : "s"); +			if (ret < pmsg->len) { +				if (ret >= 0) +					ret = -EREMOTEIO; +				goto bailout;  			}  		} else {  			/* write bytes from buffer */  			ret = sendbytes(i2c_adap, pmsg); -			DEB2(printk(KERN_DEBUG "i2c-algo-bit.o: wrote %d bytes.\n",ret)); -			if (ret < pmsg->len ) { -				return (ret<0) ? ret : -EREMOTEIO; +			if (ret >= 1) +				bit_dbg(2, &i2c_adap->dev, "wrote %d byte%s\n", +					ret, ret == 1 ? "" : "s"); +			if (ret < pmsg->len) { +				if (ret >= 0) +					ret = -EREMOTEIO; +				goto bailout;  			}  		}  	} +	ret = i; + +bailout: +	bit_dbg(3, &i2c_adap->dev, "emitting stop condition\n");  	i2c_stop(adap); -	return num; +	return ret;  }  static u32 bit_func(struct i2c_adapter *adap)  {  	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |  +	       I2C_FUNC_SMBUS_READ_BLOCK_DATA | +	       I2C_FUNC_SMBUS_BLOCK_PROC_CALL |  	       I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING;  } @@ -520,7 +556,7 @@ static const struct i2c_algorithm i2c_bit_algo = {  /*    * registering functions to load algorithms at runtime    */ -int i2c_bit_add_bus(struct i2c_adapter *adap) +static int i2c_bit_prepare_bus(struct i2c_adapter *adap)  {  	struct i2c_algo_bit_data *bit_adap = adap->algo_data; @@ -530,25 +566,39 @@ int i2c_bit_add_bus(struct i2c_adapter *adap)  			return -ENODEV;  	} -	DEB2(dev_dbg(&adap->dev, "hw routines registered.\n")); -  	/* register new adapter to i2c module... */  	adap->algo = &i2c_bit_algo;  	adap->timeout = 100;	/* default values, should	*/  	adap->retries = 3;	/* be replaced by defines	*/ +	return 0; +} + +int i2c_bit_add_bus(struct i2c_adapter *adap) +{ +	int err; + +	err = i2c_bit_prepare_bus(adap); +	if (err) +		return err; +  	return i2c_add_adapter(adap);  }  EXPORT_SYMBOL(i2c_bit_add_bus); +int i2c_bit_add_numbered_bus(struct i2c_adapter *adap) +{ +	int err; + +	err = i2c_bit_prepare_bus(adap); +	if (err) +		return err; + +	return i2c_add_numbered_adapter(adap); +} +EXPORT_SYMBOL(i2c_bit_add_numbered_bus); +  MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");  MODULE_DESCRIPTION("I2C-Bus bit-banging algorithm");  MODULE_LICENSE("GPL"); - -module_param(bit_test, bool, 0); -module_param(i2c_debug, int, S_IRUGO | S_IWUSR); - -MODULE_PARM_DESC(bit_test, "Test the lines of the bus to see if it is stuck"); -MODULE_PARM_DESC(i2c_debug, -		 "debug level - 0 off; 1 normal; 2,3 more verbose; 9 bit-protocol");  | 
