![Jean Delvare](/assets/img/avatar_default.png)
The 10-bit address support in i2c-algo-pcf is so heavily broken that it can't have ever been used. Nobody ever complained, so I'll take it that nobody needs it. Let's just delete it. Signed-off-by: Jean Delvare <khali@linux-fr.org>
439 lines
12 KiB
C
439 lines
12 KiB
C
/* ------------------------------------------------------------------------- */
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/* i2c-algo-pcf.c i2c driver algorithms for PCF8584 adapters */
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/* ------------------------------------------------------------------------- */
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/* Copyright (C) 1995-1997 Simon G. Vogl
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1998-2000 Hans Berglund
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
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/* ------------------------------------------------------------------------- */
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/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
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Frodo Looijaard <frodol@dds.nl> ,and also from Martin Bailey
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<mbailey@littlefeet-inc.com> */
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/* Partially rewriten by Oleg I. Vdovikin <vdovikin@jscc.ru> to handle multiple
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messages, proper stop/repstart signaling during receive,
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added detect code */
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/delay.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/errno.h>
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#include <linux/i2c.h>
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#include <linux/i2c-algo-pcf.h>
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#include "i2c-algo-pcf.h"
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#define DEB2(x) if (i2c_debug>=2) x
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#define DEB3(x) if (i2c_debug>=3) x /* print several statistical values*/
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#define DEBPROTO(x) if (i2c_debug>=9) x;
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/* debug the protocol by showing transferred bits */
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#define DEF_TIMEOUT 16
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/* module parameters:
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*/
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static int i2c_debug;
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/* --- setting states on the bus with the right timing: --------------- */
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#define set_pcf(adap, ctl, val) adap->setpcf(adap->data, ctl, val)
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#define get_pcf(adap, ctl) adap->getpcf(adap->data, ctl)
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#define get_own(adap) adap->getown(adap->data)
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#define get_clock(adap) adap->getclock(adap->data)
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#define i2c_outb(adap, val) adap->setpcf(adap->data, 0, val)
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#define i2c_inb(adap) adap->getpcf(adap->data, 0)
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/* --- other auxiliary functions -------------------------------------- */
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static void i2c_start(struct i2c_algo_pcf_data *adap)
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{
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DEBPROTO(printk("S "));
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set_pcf(adap, 1, I2C_PCF_START);
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}
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static void i2c_repstart(struct i2c_algo_pcf_data *adap)
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{
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DEBPROTO(printk(" Sr "));
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set_pcf(adap, 1, I2C_PCF_REPSTART);
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}
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static void i2c_stop(struct i2c_algo_pcf_data *adap)
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{
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DEBPROTO(printk("P\n"));
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set_pcf(adap, 1, I2C_PCF_STOP);
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}
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static int wait_for_bb(struct i2c_algo_pcf_data *adap) {
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int timeout = DEF_TIMEOUT;
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int status;
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status = get_pcf(adap, 1);
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#ifndef STUB_I2C
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while (timeout-- && !(status & I2C_PCF_BB)) {
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udelay(100); /* wait for 100 us */
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status = get_pcf(adap, 1);
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}
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#endif
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if (timeout <= 0) {
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printk(KERN_ERR "Timeout waiting for Bus Busy\n");
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}
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return (timeout<=0);
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}
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static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status) {
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int timeout = DEF_TIMEOUT;
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*status = get_pcf(adap, 1);
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#ifndef STUB_I2C
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while (timeout-- && (*status & I2C_PCF_PIN)) {
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adap->waitforpin();
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*status = get_pcf(adap, 1);
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}
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if (*status & I2C_PCF_LAB) {
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DEB2(printk(KERN_INFO
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"i2c-algo-pcf.o: lost arbitration (CSR 0x%02x)\n",
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*status));
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/* Cleanup from LAB-- reset and enable ESO.
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* This resets the PCF8584; since we've lost the bus, no
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* further attempts should be made by callers to clean up
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* (no i2c_stop() etc.)
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*/
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set_pcf(adap, 1, I2C_PCF_PIN);
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set_pcf(adap, 1, I2C_PCF_ESO);
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/* TODO: we should pause for a time period sufficient for any
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* running I2C transaction to complete-- the arbitration
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* logic won't work properly until the next START is seen.
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*/
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DEB2(printk(KERN_INFO
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"i2c-algo-pcf.o: reset LAB condition (CSR 0x%02x)\n",
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get_pcf(adap,1)));
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return(-EINTR);
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}
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#endif
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if (timeout <= 0)
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return(-1);
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else
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return(0);
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}
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/*
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* This should perform the 'PCF8584 initialization sequence' as described
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* in the Philips IC12 data book (1995, Aug 29).
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* There should be a 30 clock cycle wait after reset, I assume this
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* has been fulfilled.
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* There should be a delay at the end equal to the longest I2C message
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* to synchronize the BB-bit (in multimaster systems). How long is
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* this? I assume 1 second is always long enough.
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*
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* vdovikin: added detect code for PCF8584
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*/
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static int pcf_init_8584 (struct i2c_algo_pcf_data *adap)
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{
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unsigned char temp;
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DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: PCF state 0x%02x\n", get_pcf(adap, 1)));
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/* S1=0x80: S0 selected, serial interface off */
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set_pcf(adap, 1, I2C_PCF_PIN);
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/* check to see S1 now used as R/W ctrl -
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PCF8584 does that when ESO is zero */
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if (((temp = get_pcf(adap, 1)) & 0x7f) != (0)) {
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DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S0 (0x%02x).\n", temp));
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return -ENXIO; /* definetly not PCF8584 */
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}
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/* load own address in S0, effective address is (own << 1) */
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i2c_outb(adap, get_own(adap));
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/* check it's really written */
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if ((temp = i2c_inb(adap)) != get_own(adap)) {
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DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S0 (0x%02x).\n", temp));
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return -ENXIO;
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}
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/* S1=0xA0, next byte in S2 */
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set_pcf(adap, 1, I2C_PCF_PIN | I2C_PCF_ES1);
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/* check to see S2 now selected */
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if (((temp = get_pcf(adap, 1)) & 0x7f) != I2C_PCF_ES1) {
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DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S2 (0x%02x).\n", temp));
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return -ENXIO;
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}
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/* load clock register S2 */
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i2c_outb(adap, get_clock(adap));
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/* check it's really written, the only 5 lowest bits does matter */
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if (((temp = i2c_inb(adap)) & 0x1f) != get_clock(adap)) {
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DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S2 (0x%02x).\n", temp));
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return -ENXIO;
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}
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/* Enable serial interface, idle, S0 selected */
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set_pcf(adap, 1, I2C_PCF_IDLE);
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/* check to see PCF is really idled and we can access status register */
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if ((temp = get_pcf(adap, 1)) != (I2C_PCF_PIN | I2C_PCF_BB)) {
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DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S1` (0x%02x).\n", temp));
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return -ENXIO;
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}
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printk(KERN_DEBUG "i2c-algo-pcf.o: deteted and initialized PCF8584.\n");
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return 0;
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}
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/* ----- Utility functions
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*/
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static int pcf_sendbytes(struct i2c_adapter *i2c_adap, const char *buf,
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int count, int last)
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{
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struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
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int wrcount, status, timeout;
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for (wrcount=0; wrcount<count; ++wrcount) {
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DEB2(dev_dbg(&i2c_adap->dev, "i2c_write: writing %2.2X\n",
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buf[wrcount]&0xff));
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i2c_outb(adap, buf[wrcount]);
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timeout = wait_for_pin(adap, &status);
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if (timeout) {
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if (timeout == -EINTR) {
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/* arbitration lost */
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return -EINTR;
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}
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i2c_stop(adap);
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dev_err(&i2c_adap->dev, "i2c_write: error - timeout.\n");
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return -EREMOTEIO; /* got a better one ?? */
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}
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#ifndef STUB_I2C
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if (status & I2C_PCF_LRB) {
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i2c_stop(adap);
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dev_err(&i2c_adap->dev, "i2c_write: error - no ack.\n");
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return -EREMOTEIO; /* got a better one ?? */
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}
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#endif
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}
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if (last) {
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i2c_stop(adap);
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}
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else {
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i2c_repstart(adap);
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}
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return (wrcount);
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}
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static int pcf_readbytes(struct i2c_adapter *i2c_adap, char *buf,
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int count, int last)
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{
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int i, status;
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struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
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int wfp;
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/* increment number of bytes to read by one -- read dummy byte */
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for (i = 0; i <= count; i++) {
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if ((wfp = wait_for_pin(adap, &status))) {
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if (wfp == -EINTR) {
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/* arbitration lost */
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return -EINTR;
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}
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i2c_stop(adap);
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dev_err(&i2c_adap->dev, "pcf_readbytes timed out.\n");
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return (-1);
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}
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#ifndef STUB_I2C
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if ((status & I2C_PCF_LRB) && (i != count)) {
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i2c_stop(adap);
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dev_err(&i2c_adap->dev, "i2c_read: i2c_inb, No ack.\n");
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return (-1);
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}
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#endif
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if (i == count - 1) {
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set_pcf(adap, 1, I2C_PCF_ESO);
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} else
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if (i == count) {
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if (last) {
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i2c_stop(adap);
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} else {
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i2c_repstart(adap);
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}
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};
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if (i) {
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buf[i - 1] = i2c_inb(adap);
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} else {
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i2c_inb(adap); /* dummy read */
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}
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}
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return (i - 1);
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}
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static int pcf_doAddress(struct i2c_algo_pcf_data *adap,
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struct i2c_msg *msg)
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{
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unsigned short flags = msg->flags;
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unsigned char addr;
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addr = msg->addr << 1;
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if (flags & I2C_M_RD)
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addr |= 1;
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if (flags & I2C_M_REV_DIR_ADDR)
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addr ^= 1;
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i2c_outb(adap, addr);
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return 0;
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}
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static int pcf_xfer(struct i2c_adapter *i2c_adap,
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struct i2c_msg *msgs,
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int num)
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{
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struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
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struct i2c_msg *pmsg;
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int i;
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int ret=0, timeout, status;
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/* Check for bus busy */
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timeout = wait_for_bb(adap);
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if (timeout) {
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DEB2(printk(KERN_ERR "i2c-algo-pcf.o: "
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"Timeout waiting for BB in pcf_xfer\n");)
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return -EIO;
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}
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for (i = 0;ret >= 0 && i < num; i++) {
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pmsg = &msgs[i];
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DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: Doing %s %d bytes to 0x%02x - %d of %d messages\n",
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pmsg->flags & I2C_M_RD ? "read" : "write",
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pmsg->len, pmsg->addr, i + 1, num);)
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ret = pcf_doAddress(adap, pmsg);
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/* Send START */
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if (i == 0) {
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i2c_start(adap);
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}
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/* Wait for PIN (pending interrupt NOT) */
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timeout = wait_for_pin(adap, &status);
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if (timeout) {
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if (timeout == -EINTR) {
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/* arbitration lost */
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return (-EINTR);
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}
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i2c_stop(adap);
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DEB2(printk(KERN_ERR "i2c-algo-pcf.o: Timeout waiting "
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"for PIN(1) in pcf_xfer\n");)
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return (-EREMOTEIO);
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}
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#ifndef STUB_I2C
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/* Check LRB (last rcvd bit - slave ack) */
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if (status & I2C_PCF_LRB) {
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i2c_stop(adap);
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DEB2(printk(KERN_ERR "i2c-algo-pcf.o: No LRB(1) in pcf_xfer\n");)
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return (-EREMOTEIO);
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}
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#endif
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DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: Msg %d, addr=0x%x, flags=0x%x, len=%d\n",
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i, msgs[i].addr, msgs[i].flags, msgs[i].len);)
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/* Read */
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if (pmsg->flags & I2C_M_RD) {
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/* read bytes into buffer*/
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ret = pcf_readbytes(i2c_adap, pmsg->buf, pmsg->len,
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(i + 1 == num));
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if (ret != pmsg->len) {
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DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
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"only read %d bytes.\n",ret));
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} else {
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DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: read %d bytes.\n",ret));
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}
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} else { /* Write */
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ret = pcf_sendbytes(i2c_adap, pmsg->buf, pmsg->len,
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(i + 1 == num));
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if (ret != pmsg->len) {
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DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: "
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"only wrote %d bytes.\n",ret));
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} else {
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DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: wrote %d bytes.\n",ret));
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}
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}
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}
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return (i);
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}
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static u32 pcf_func(struct i2c_adapter *adap)
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{
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return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
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I2C_FUNC_PROTOCOL_MANGLING;
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}
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/* -----exported algorithm data: ------------------------------------- */
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static const struct i2c_algorithm pcf_algo = {
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.master_xfer = pcf_xfer,
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.functionality = pcf_func,
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};
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/*
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* registering functions to load algorithms at runtime
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*/
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int i2c_pcf_add_bus(struct i2c_adapter *adap)
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{
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struct i2c_algo_pcf_data *pcf_adap = adap->algo_data;
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int rval;
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DEB2(dev_dbg(&adap->dev, "hw routines registered.\n"));
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/* register new adapter to i2c module... */
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adap->algo = &pcf_algo;
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adap->timeout = 100;
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if ((rval = pcf_init_8584(pcf_adap)))
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return rval;
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rval = i2c_add_adapter(adap);
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return rval;
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}
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EXPORT_SYMBOL(i2c_pcf_add_bus);
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MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>");
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MODULE_DESCRIPTION("I2C-Bus PCF8584 algorithm");
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MODULE_LICENSE("GPL");
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module_param(i2c_debug, int, S_IRUGO | S_IWUSR);
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MODULE_PARM_DESC(i2c_debug,
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"debug level - 0 off; 1 normal; 2,3 more verbose; 9 pcf-protocol");
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