diff options
Diffstat (limited to 'drivers/i2c/algos/i2c-algo-bit.c')
| -rw-r--r-- | drivers/i2c/algos/i2c-algo-bit.c | 621 |
1 files changed, 361 insertions, 260 deletions
diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c index df05df1a0ef..65ef9664d5d 100644 --- a/drivers/i2c/algos/i2c-algo-bit.c +++ b/drivers/i2c/algos/i2c-algo-bit.c @@ -1,7 +1,7 @@ -/* ------------------------------------------------------------------------- */ -/* i2c-algo-bit.c i2c driver algorithms for bit-shift adapters */ -/* ------------------------------------------------------------------------- */ -/* Copyright (C) 1995-2000 Simon G. Vogl +/* ------------------------------------------------------------------------- + * i2c-algo-bit.c i2c driver algorithms for bit-shift adapters + * ------------------------------------------------------------------------- + * Copyright (C) 1995-2000 Simon G. Vogl 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 @@ -15,17 +15,16 @@ 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. */ -/* ------------------------------------------------------------------------- */ + Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, + MA 02110-1301 USA. + * ------------------------------------------------------------------------- */ -/* With some changes from Frodo Looijaard <frodol@dds.nl>, Kyösti Mälkki - <kmalkki@cc.hut.fi> and Jean Delvare <khali@linux-fr.org> */ +/* With some changes from Frodo Looijaard <frodol@dds.nl>, Kyösti Mälkki + <kmalkki@cc.hut.fi> and Jean Delvare <jdelvare@suse.de> */ #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/sched.h> #include <linux/i2c.h> @@ -33,120 +32,138 @@ /* ----- 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, int, S_IRUGO); +MODULE_PARM_DESC(bit_test, "lines testing - 0 off; 1 report; 2 fail if 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: --------------- */ -#define setsda(adap,val) adap->setsda(adap->data, val) -#define setscl(adap,val) adap->setscl(adap->data, val) -#define getsda(adap) adap->getsda(adap->data) -#define getscl(adap) adap->getscl(adap->data) +#define setsda(adap, val) adap->setsda(adap->data, val) +#define setscl(adap, val) adap->setscl(adap->data, val) +#define getsda(adap) adap->getsda(adap->data) +#define getscl(adap) adap->getscl(adap->data) static inline void sdalo(struct i2c_algo_bit_data *adap) { - setsda(adap,0); - udelay(adap->udelay); + setsda(adap, 0); + udelay((adap->udelay + 1) / 2); } static inline void sdahi(struct i2c_algo_bit_data *adap) { - setsda(adap,1); - udelay(adap->udelay); + setsda(adap, 1); + udelay((adap->udelay + 1) / 2); } static inline void scllo(struct i2c_algo_bit_data *adap) { - setscl(adap,0); - udelay(adap->udelay); + setscl(adap, 0); + udelay(adap->udelay / 2); } /* * Raise scl line, and do checking for delays. This is necessary for slower * devices. */ -static inline int sclhi(struct i2c_algo_bit_data *adap) +static int sclhi(struct i2c_algo_bit_data *adap) { unsigned long start; - setscl(adap,1); + setscl(adap, 1); /* Not all adapters have scl sense line... */ - if (adap->getscl == NULL ) { - udelay(adap->udelay); - return 0; - } - - start=jiffies; - while (! getscl(adap) ) { - /* the hw knows how to read the clock line, - * so we wait until it actually gets high. - * This is safer as some chips may hold it low - * while they are processing data internally. - */ - if (time_after_eq(jiffies, start+adap->timeout)) { + if (!adap->getscl) + goto done; + + start = jiffies; + while (!getscl(adap)) { + /* This hw knows how to read the clock line, so we wait + * until it actually gets high. This is safer as some + * chips may hold it low ("clock stretching") while they + * are processing data internally. + */ + if (time_after(jiffies, start + adap->timeout)) { + /* Test one last time, as we may have been preempted + * between last check and timeout test. + */ + if (getscl(adap)) + break; return -ETIMEDOUT; } - cond_resched(); + cpu_relax(); } - 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); return 0; -} +} /* --- other auxiliary functions -------------------------------------- */ -static void i2c_start(struct i2c_algo_bit_data *adap) +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) +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); + setsda(adap, 0); udelay(adap->udelay); - - sdalo(adap); scllo(adap); } -static void i2c_stop(struct i2c_algo_bit_data *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); + sclhi(adap); + setsda(adap, 1); + udelay(adap->udelay); } -/* send a byte without start cond., look for arbitration, +/* send a byte without start cond., look for arbitration, check ackn. from slave */ /* returns: * 1 if the device acknowledged * 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; @@ -154,145 +171,161 @@ static int i2c_outb(struct i2c_adapter *i2c_adap, char c) struct i2c_algo_bit_data *adap = i2c_adap->algo_data; /* assert: scl is low */ - for ( i=7 ; i>=0 ; i-- ) { - sb = c & ( 1 << i ); - setsda(adap,sb); - udelay(adap->udelay); - DEBPROTO(printk(KERN_DEBUG "%d",sb!=0)); - 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)); + for (i = 7; i >= 0; i--) { + sb = (c >> i) & 1; + setsda(adap, sb); + udelay((adap->udelay + 1) / 2); + if (sclhi(adap) < 0) { /* timed out */ + 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. + } + /* FIXME do arbitration here: + * if (sb && !getsda(adap)) -> ouch! Get out of here. + * + * Report a unique code, so higher level code can retry + * the whole (combined) message and *NOT* issue STOP. */ - 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; - }; - /* 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)); - - DEBPROTO( printk(KERN_DEBUG "[%2.2x]",c&0xff) ); - DEBPROTO(if (0==ack){ printk(KERN_DEBUG " A ");} else printk(KERN_DEBUG " NA ") ); + if (sclhi(adap) < 0) { /* timeout */ + 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, or it may + * NAK (usually to report problems with the data we wrote). + */ + 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"); + scllo(adap); - return 0==ack; /* return 1 if device acked */ + return ack; /* assert: scl is low (sda undef) */ } -static int i2c_inb(struct i2c_adapter *i2c_adap) +static int i2c_inb(struct i2c_adapter *i2c_adap) { /* read byte via i2c port, without start/stop sequence */ /* acknowledge is sent in i2c_read. */ int i; - unsigned char indata=0; + unsigned char indata = 0; struct i2c_algo_bit_data *adap = i2c_adap->algo_data; /* assert: scl is low */ 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)); + for (i = 0; i < 8; i++) { + if (sclhi(adap) < 0) { /* timeout */ + bit_dbg(1, &i2c_adap->dev, "i2c_inb: timeout at bit " + "#%d\n", 7 - i); return -ETIMEDOUT; - }; + } indata *= 2; - if ( getsda(adap) ) + 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; } /* * Sanity check for the adapter hardware - check the reaction of * the bus lines only if it seems to be idle. */ -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"); - - 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); +static int test_bus(struct i2c_adapter *i2c_adap) +{ + struct i2c_algo_bit_data *adap = i2c_adap->algo_data; + const char *name = i2c_adap->name; + int scl, sda, ret; + + if (adap->pre_xfer) { + ret = adap->pre_xfer(i2c_adap); + if (ret < 0) + return -ENODEV; + } + + if (adap->getscl == NULL) + pr_info("%s: Testing SDA only, SCL is not readable\n", name); + + sda = getsda(adap); + scl = (adap->getscl == NULL) ? 1 : getscl(adap); + if (!scl || !sda) { + printk(KERN_WARNING + "%s: bus seems to be busy (scl=%d, sda=%d)\n", + name, scl, sda); 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"); + sda = getsda(adap); + scl = (adap->getscl == NULL) ? 1 : getscl(adap); + if (sda) { + 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"); + if (!scl) { + 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"); + sda = getsda(adap); + scl = (adap->getscl == NULL) ? 1 : getscl(adap); + if (!sda) { + 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"); + if (!scl) { + 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"); + sda = getsda(adap); + scl = (adap->getscl == NULL) ? 0 : getscl(adap); + if (scl) { + 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"); + if (!sda) { + 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"); + sda = getsda(adap); + scl = (adap->getscl == NULL) ? 1 : getscl(adap); + if (!scl) { + 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"); + if (!sda) { + 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); + + if (adap->post_xfer) + adap->post_xfer(i2c_adap); + + pr_info("%s: Test OK\n", name); return 0; bailout: sdahi(adap); sclhi(adap); + + if (adap->post_xfer) + adap->post_xfer(i2c_adap); + return -ENODEV; } @@ -306,101 +339,136 @@ bailout: * 0 chip did not answer * -x transmission error */ -static inline int try_address(struct i2c_adapter *i2c_adap, +static int try_address(struct i2c_adapter *i2c_adap, unsigned char addr, int retries) { struct i2c_algo_bit_data *adap = i2c_adap->algo_data; - 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 */ + int i, ret = 0; + + for (i = 0; i <= retries; i++) { + ret = i2c_outb(i2c_adap, addr); + 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; + unsigned short nak_ok = msg->flags & I2C_M_IGNORE_NAK; int retval; - int wrcount=0; + 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); - if ((retval>0) || (nak_ok && (retval==0))) { /* ok or ignored NAK */ - count--; + retval = i2c_outb(i2c_adap, *temp); + + /* OK/ACK; or ignored NAK */ + if ((retval > 0) || (nak_ok && (retval == 0))) { + 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 ?? */ + + /* A slave NAKing the master means the slave didn't like + * something about the data it saw. For example, maybe + * the SMBus PEC was wrong. + */ + } else if (retval == 0) { + dev_err(&i2c_adap->dev, "sendbytes: NAK bailout.\n"); + return -EIO; + + /* Timeout; or (someday) lost arbitration + * + * FIXME Lost ARB implies retrying the transaction from + * the first message, after the "winning" master issues + * its STOP. As a rule, upper layer code has no reason + * to know or care about this ... it is *NOT* an error. + */ + } else { + dev_err(&i2c_adap->dev, "sendbytes: error %d\n", + retval); + return retval; } -#if 0 - /* from asm/delay.h */ - __delay(adap->mdelay * (loops_per_sec / 1000) ); -#endif } return wrcount; } -static inline int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) +static int acknak(struct i2c_adapter *i2c_adap, int is_ack) { - int inval; - int rdcount=0; /* counts bytes read */ struct i2c_algo_bit_data *adap = i2c_adap->algo_data; - char *temp = msg->buf; + + /* assert: sda is high */ + if (is_ack) /* send ack */ + setsda(adap, 0); + udelay((adap->udelay + 1) / 2); + if (sclhi(adap) < 0) { /* timeout */ + dev_err(&i2c_adap->dev, "readbytes: ack/nak timeout\n"); + return -ETIMEDOUT; + } + scllo(adap); + return 0; +} + +static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) +{ + int inval; + int rdcount = 0; /* counts bytes read */ + unsigned char *temp = msg->buf; int count = msg->len; + const unsigned flags = msg->flags; while (count > 0) { inval = i2c_inb(i2c_adap); -/*printk("%#02x ",inval); if ( ! (count % 16) ) printk("\n"); */ - if (inval>=0) { + if (inval >= 0) { *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) - continue; + /* Some SMBus transactions require that we receive the + transaction length as the first read byte. */ + if (rdcount == 1 && (flags & I2C_M_RECV_LEN)) { + if (inval <= 0 || inval > I2C_SMBUS_BLOCK_MAX) { + if (!(flags & I2C_M_NO_RD_ACK)) + acknak(i2c_adap, 0); + dev_err(&i2c_adap->dev, "readbytes: invalid " + "block length (%d)\n", inval); + return -EPROTO; + } + /* 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; + } + + bit_dbg(2, &i2c_adap->dev, "readbytes: 0x%02x %s\n", + inval, + (flags & I2C_M_NO_RD_ACK) + ? "(no ack/nak)" + : (count ? "A" : "NA")); - if ( count > 0 ) { /* send ack */ - sdalo(adap); - DEBPROTO(printk(" Am ")); - } else { - sdahi(adap); /* neg. ack on last byte */ - DEBPROTO(printk(" NAm ")); + if (!(flags & I2C_M_NO_RD_ACK)) { + inval = acknak(i2c_adap, count); + if (inval < 0) + return inval; } - if (sclhi(adap)<0) { /* timeout */ - sdahi(adap); - printk(KERN_ERR "i2c-algo-bit.o: readbytes: Timeout at ack\n"); - return -ETIMEDOUT; - }; - scllo(adap); - sdahi(adap); } return rdcount; } @@ -410,10 +478,10 @@ static inline int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) * reads, writes as well as 10bit-addresses. * returns: * 0 everything went okay, the chip ack'ed, or IGNORE_NAK flag was set - * -x an error occurred (like: -EREMOTEIO if the device did not answer, or - * -ETIMEDOUT, for example if the lines are stuck...) + * -x an error occurred (like: -ENXIO if the device did not answer, or + * -ETIMEDOUT, for example if the lines are stuck...) */ -static inline int bit_doAddress(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) +static int bit_doAddress(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) { unsigned short flags = msg->flags; unsigned short nak_ok = msg->flags & I2C_M_IGNORE_NAK; @@ -423,43 +491,47 @@ static inline int bit_doAddress(struct i2c_adapter *i2c_adap, struct i2c_msg *ms int ret, retries; retries = nak_ok ? 0 : i2c_adap->retries; - - if ( (flags & I2C_M_TEN) ) { + + if (flags & I2C_M_TEN) { /* a ten bit address */ - addr = 0xf0 | (( msg->addr >> 7) & 0x03); - DEB2(printk(KERN_DEBUG "addr0: %d\n",addr)); + addr = 0xf0 | ((msg->addr >> 7) & 0x06); + 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"); - return -EREMOTEIO; + dev_err(&i2c_adap->dev, + "died at extended address code\n"); + return -ENXIO; } /* the remaining 8 bit address */ - ret = i2c_outb(i2c_adap,msg->addr & 0x7f); + ret = i2c_outb(i2c_adap, msg->addr & 0xff); if ((ret != 1) && !nak_ok) { /* the chip did not ack / xmission error occurred */ - printk(KERN_ERR "died at 2nd address code.\n"); - return -EREMOTEIO; + dev_err(&i2c_adap->dev, "died at 2nd address code\n"); + return -ENXIO; } - if ( flags & I2C_M_RD ) { + 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"); - return -EREMOTEIO; + if ((ret != 1) && !nak_ok) { + dev_err(&i2c_adap->dev, + "died at repeated address code\n"); + return -EIO; } } } else { /* normal 7bit address */ - addr = ( msg->addr << 1 ); - if (flags & I2C_M_RD ) + addr = msg->addr << 1; + if (flags & I2C_M_RD) addr |= 1; - if (flags & I2C_M_REV_DIR_ADDR ) + if (flags & I2C_M_REV_DIR_ADDR) addr ^= 1; ret = try_address(i2c_adap, addr, retries); - if ((ret!=1) && !nak_ok) - return -EREMOTEIO; + if ((ret != 1) && !nak_ok) + return -ENXIO; } return 0; @@ -470,100 +542,129 @@ static int bit_xfer(struct i2c_adapter *i2c_adap, { struct i2c_msg *pmsg; struct i2c_algo_bit_data *adap = i2c_adap->algo_data; - - int i,ret; + int i, ret; unsigned short nak_ok; + if (adap->pre_xfer) { + ret = adap->pre_xfer(i2c_adap); + if (ret < 0) + return ret; + } + + bit_dbg(3, &i2c_adap->dev, "emitting start condition\n"); i2c_start(adap); - for (i=0;i<num;i++) { + for (i = 0; i < num; i++) { pmsg = &msgs[i]; - nak_ok = pmsg->flags & I2C_M_IGNORE_NAK; + 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 ) { + 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 = -EIO; + 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 = -EIO; + goto bailout; } } } + ret = i; + +bailout: + bit_dbg(3, &i2c_adap->dev, "emitting stop condition\n"); i2c_stop(adap); - return num; + + if (adap->post_xfer) + adap->post_xfer(i2c_adap); + return ret; } static u32 bit_func(struct i2c_adapter *adap) { - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | + return I2C_FUNC_I2C | I2C_FUNC_NOSTART | I2C_FUNC_SMBUS_EMUL | + I2C_FUNC_SMBUS_READ_BLOCK_DATA | + I2C_FUNC_SMBUS_BLOCK_PROC_CALL | I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING; } /* -----exported algorithm data: ------------------------------------- */ -static struct i2c_algorithm i2c_bit_algo = { +const struct i2c_algorithm i2c_bit_algo = { .master_xfer = bit_xfer, .functionality = bit_func, }; +EXPORT_SYMBOL(i2c_bit_algo); -/* - * registering functions to load algorithms at runtime +/* + * registering functions to load algorithms at runtime */ -int i2c_bit_add_bus(struct i2c_adapter *adap) +static int __i2c_bit_add_bus(struct i2c_adapter *adap, + int (*add_adapter)(struct i2c_adapter *)) { struct i2c_algo_bit_data *bit_adap = adap->algo_data; + int ret; if (bit_test) { - int ret = test_bus(bit_adap, adap->name); - if (ret<0) + ret = test_bus(adap); + if (bit_test >= 2 && ret < 0) return -ENODEV; } - DEB2(dev_dbg(&adap->dev, "hw routines registered.\n")); - /* register new adapter to i2c module... */ adap->algo = &i2c_bit_algo; + adap->retries = 3; - adap->timeout = 100; /* default values, should */ - adap->retries = 3; /* be replaced by defines */ + ret = add_adapter(adap); + if (ret < 0) + return ret; - i2c_add_adapter(adap); + /* Complain if SCL can't be read */ + if (bit_adap->getscl == NULL) { + dev_warn(&adap->dev, "Not I2C compliant: can't read SCL\n"); + dev_warn(&adap->dev, "Bus may be unreliable\n"); + } return 0; } - -int i2c_bit_del_bus(struct i2c_adapter *adap) +int i2c_bit_add_bus(struct i2c_adapter *adap) { - return i2c_del_adapter(adap); + return __i2c_bit_add_bus(adap, i2c_add_adapter); } - EXPORT_SYMBOL(i2c_bit_add_bus); -EXPORT_SYMBOL(i2c_bit_del_bus); + +int i2c_bit_add_numbered_bus(struct i2c_adapter *adap) +{ + return __i2c_bit_add_bus(adap, i2c_add_numbered_adapter); +} +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"); |