diff options
Diffstat (limited to 'drivers/i2c/algos/i2c-algo-pcf.c')
| -rw-r--r-- | drivers/i2c/algos/i2c-algo-pcf.c | 261 |
1 files changed, 121 insertions, 140 deletions
diff --git a/drivers/i2c/algos/i2c-algo-pcf.c b/drivers/i2c/algos/i2c-algo-pcf.c index 3e01992230b8..7ce75775ec73 100644 --- a/drivers/i2c/algos/i2c-algo-pcf.c +++ b/drivers/i2c/algos/i2c-algo-pcf.c @@ -1,31 +1,30 @@ -/* ------------------------------------------------------------------------- */ -/* 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 Kyösti Mälkki <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 */ +/* + * 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 Kyösti Mälkki <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> @@ -38,17 +37,18 @@ #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 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: +/* + * module parameters: */ static int i2c_debug; -/* --- setting states on the bus with the right timing: --------------- */ +/* 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) @@ -57,22 +57,21 @@ static int i2c_debug; #define i2c_outb(adap, val) adap->setpcf(adap->data, 0, val) #define i2c_inb(adap) adap->getpcf(adap->data, 0) -/* --- other auxiliary functions -------------------------------------- */ +/* other auxiliary functions */ -static void i2c_start(struct i2c_algo_pcf_data *adap) +static void i2c_start(struct i2c_algo_pcf_data *adap) { - DEBPROTO(printk("S ")); + DEBPROTO(printk(KERN_DEBUG "S ")); set_pcf(adap, 1, I2C_PCF_START); } -static void i2c_repstart(struct i2c_algo_pcf_data *adap) +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) +static void i2c_stop(struct i2c_algo_pcf_data *adap) { DEBPROTO(printk("P\n")); set_pcf(adap, 1, I2C_PCF_STOP); @@ -82,17 +81,17 @@ static void handle_lab(struct i2c_algo_pcf_data *adap, const int *status) { DEB2(printk(KERN_INFO "i2c-algo-pcf.o: lost arbitration (CSR 0x%02x)\n", - *status)); - - /* Cleanup from LAB -- reset and enable ESO. + *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); - - /* We pause for a time period sufficient for any running + /* + * We 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. * It is assumed the bus driver or client has set a proper value. @@ -108,48 +107,50 @@ static void handle_lab(struct i2c_algo_pcf_data *adap, const int *status) get_pcf(adap, 1))); } -static int wait_for_bb(struct i2c_algo_pcf_data *adap) { +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)) { + + while (!(status & I2C_PCF_BB) && --timeout) { udelay(100); /* wait for 100 us */ status = get_pcf(adap, 1); } -#endif - if (timeout <= 0) { + + if (timeout == 0) { printk(KERN_ERR "Timeout waiting for Bus Busy\n"); + return -ETIMEDOUT; } - - return (timeout<=0); -} + return 0; +} -static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status) { +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)) { + + while ((*status & I2C_PCF_PIN) && --timeout) { adap->waitforpin(adap->data); *status = get_pcf(adap, 1); } if (*status & I2C_PCF_LAB) { handle_lab(adap, status); - return(-EINTR); + return -EINTR; } -#endif - if (timeout <= 0) - return(-1); - else - return(0); + + if (timeout == 0) + return -ETIMEDOUT; + + 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 @@ -164,18 +165,21 @@ 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))); + 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 */ + /* + * 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) */ + /* 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)) { @@ -183,7 +187,7 @@ static int pcf_init_8584 (struct i2c_algo_pcf_data *adap) return -ENXIO; } - /* S1=0xA0, next byte in S2 */ + /* 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) { @@ -191,7 +195,7 @@ static int pcf_init_8584 (struct i2c_algo_pcf_data *adap) return -ENXIO; } - /* load clock register S2 */ + /* 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)) { @@ -199,7 +203,7 @@ static int pcf_init_8584 (struct i2c_algo_pcf_data *adap) return -ENXIO; } - /* Enable serial interface, idle, S0 selected */ + /* 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 */ @@ -207,57 +211,47 @@ static int pcf_init_8584 (struct i2c_algo_pcf_data *adap) 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: detected and initialized PCF8584.\n"); return 0; } - -/* ----- Utility functions - */ - static int pcf_sendbytes(struct i2c_adapter *i2c_adap, const char *buf, - int count, int last) + 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)); + buf[wrcount] & 0xff)); i2c_outb(adap, buf[wrcount]); timeout = wait_for_pin(adap, &status); if (timeout) { - if (timeout == -EINTR) { - /* arbitration lost */ - return -EINTR; - } + if (timeout == -EINTR) + return -EINTR; /* arbitration lost */ + 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) { + if (last) i2c_stop(adap); - } - else { + else i2c_repstart(adap); - } - return (wrcount); + return wrcount; } - static int pcf_readbytes(struct i2c_adapter *i2c_adap, char *buf, - int count, int last) + int count, int last) { int i, status; struct i2c_algo_pcf_data *adap = i2c_adap->algo_data; @@ -267,42 +261,36 @@ static int pcf_readbytes(struct i2c_adapter *i2c_adap, char *buf, for (i = 0; i <= count; i++) { if ((wfp = wait_for_pin(adap, &status))) { - if (wfp == -EINTR) { - /* arbitration lost */ - return -EINTR; - } + if (wfp == -EINTR) + return -EINTR; /* arbitration lost */ + i2c_stop(adap); dev_err(&i2c_adap->dev, "pcf_readbytes timed out.\n"); - return (-1); + 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); + return -1; } -#endif - + if (i == count - 1) { set_pcf(adap, 1, I2C_PCF_ESO); - } else - if (i == count) { - if (last) { + } else if (i == count) { + if (last) i2c_stop(adap); - } else { + else i2c_repstart(adap); - } - }; + } - if (i) { + if (i) buf[i - 1] = i2c_inb(adap); - } else { + else i2c_inb(adap); /* dummy read */ - } } - return (i - 1); + return i - 1; } @@ -323,14 +311,14 @@ static int pcf_doAddress(struct i2c_algo_pcf_data *adap, } static int pcf_xfer(struct i2c_adapter *i2c_adap, - struct i2c_msg *msgs, + 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; - + if (adap->xfer_begin) adap->xfer_begin(adap->data); @@ -338,25 +326,24 @@ static int pcf_xfer(struct i2c_adapter *i2c_adap, timeout = wait_for_bb(adap); if (timeout) { DEB2(printk(KERN_ERR "i2c-algo-pcf.o: " - "Timeout waiting for BB in pcf_xfer\n");) + "Timeout waiting for BB in pcf_xfer\n");) i = -EIO; goto out; } - + 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);) - + pmsg->len, pmsg->addr, i + 1, num);) + ret = pcf_doAddress(adap, pmsg); /* Send START */ - if (i == 0) { - i2c_start(adap); - } - + if (i == 0) + i2c_start(adap); + /* Wait for PIN (pending interrupt NOT) */ timeout = wait_for_pin(adap, &status); if (timeout) { @@ -371,8 +358,7 @@ static int pcf_xfer(struct i2c_adapter *i2c_adap, i = -EREMOTEIO; goto out; } - -#ifndef STUB_I2C + /* Check LRB (last rcvd bit - slave ack) */ if (status & I2C_PCF_LRB) { i2c_stop(adap); @@ -380,27 +366,24 @@ static int pcf_xfer(struct i2c_adapter *i2c_adap, i = -EREMOTEIO; goto out; } -#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)); - + (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 */ + } else { ret = pcf_sendbytes(i2c_adap, pmsg->buf, pmsg->len, - (i + 1 == num)); - + (i + 1 == num)); + if (ret != pmsg->len) { DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: " "only wrote %d bytes.\n",ret)); @@ -413,24 +396,23 @@ static int pcf_xfer(struct i2c_adapter *i2c_adap, out: if (adap->xfer_end) adap->xfer_end(adap->data); - return (i); + return i; } static u32 pcf_func(struct i2c_adapter *adap) { - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING; } -/* -----exported algorithm data: ------------------------------------- */ - +/* exported algorithm data: */ static const struct i2c_algorithm pcf_algo = { .master_xfer = pcf_xfer, .functionality = pcf_func, }; -/* - * registering functions to load algorithms at runtime +/* + * registering functions to load algorithms at runtime */ int i2c_pcf_add_bus(struct i2c_adapter *adap) { @@ -441,7 +423,6 @@ int i2c_pcf_add_bus(struct i2c_adapter *adap) /* register new adapter to i2c module... */ adap->algo = &pcf_algo; - adap->timeout = 100; if ((rval = pcf_init_8584(pcf_adap))) return rval; @@ -458,4 +439,4 @@ 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"); + "debug level - 0 off; 1 normal; 2,3 more verbose; 9 pcf-protocol"); |
