freebsd-dev/sys/dev/pcf/pcf.c
Joerg Wunsch e0efc557e7 Round #1 of improving pcf(4).
This splits the driver into a bus-independant backend, plus bus-specific
frontends.  The old pcf(4) (i386/ISA) frontend is now in pcf_isa.c, the
frontend in envctrl.c is for sparc64/Ebus2 (Sun device name: SUNW,envctrl
from Sun E450 machines).  More frontends are expected to appear in future.

This is not yet ready for public consumption, but it basically works.
Nicolas will bring over his ISA-specific fixes soon.

Reviewed by:	nsouch
2004-05-25 07:42:45 +00:00

436 lines
8.8 KiB
C

/*-
* Copyright (c) 1998 Nicolas Souchu, Marc Bouget
* Copyright (c) 2004 Joerg Wunsch
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/rman.h>
#include <dev/iicbus/iiconf.h>
#include <dev/pcf/pcfvar.h>
#include "iicbus_if.h"
/* Not so official debugging option. */
/* #define PCFDEBUG */
static int pcf_wait_byte(struct pcf_softc *pcf);
static int pcf_noack(struct pcf_softc *pcf, int timeout);
/*
* Polling mode for master operations wait for a new
* byte incomming or outgoing
*/
int
pcf_wait_byte(struct pcf_softc *sc)
{
int counter = TIMEOUT;
while (counter--) {
if ((pcf_get_S1(sc) & PIN) == 0)
return (0);
}
return (IIC_ETIMEOUT);
}
int
pcf_stop(device_t dev)
{
struct pcf_softc *sc = DEVTOSOFTC(dev);
#ifdef PCFDEBUG
device_printf(dev, " >> stop\n");
#endif
/*
* Send STOP condition iff the START condition was previously sent.
* STOP is sent only once even if an iicbus_stop() is called after
* an iicbus_read()... see pcf_read(): the PCF needs to send the stop
* before the last char is read.
*/
if (sc->pcf_started) {
/* set stop condition and enable IT */
pcf_set_S1(sc, PIN|ESO|ENI|STO|ACK);
sc->pcf_started = 0;
}
return (0);
}
int
pcf_noack(struct pcf_softc *sc, int timeout)
{
int noack;
int k = timeout/10;
do {
noack = pcf_get_S1(sc) & LRB;
if (!noack)
break;
DELAY(10); /* XXX wait 10 us */
} while (k--);
return (noack);
}
int
pcf_repeated_start(device_t dev, u_char slave, int timeout)
{
struct pcf_softc *sc = DEVTOSOFTC(dev);
int error = 0;
#ifdef PCFDEBUG
device_printf(dev, " >> repeated start for slave %#x\n",
(unsigned)slave);
#endif
/* repeated start */
pcf_set_S1(sc, ESO|STA|STO|ACK);
/* set slave address to PCF. Last bit (LSB) must be set correctly
* according to transfer direction */
pcf_set_S0(sc, slave);
/* wait for address sent, polling */
if ((error = pcf_wait_byte(sc)))
goto error;
/* check for ack */
if (pcf_noack(sc, timeout)) {
error = IIC_ENOACK;
goto error;
}
return (0);
error:
pcf_stop(dev);
return (error);
}
int
pcf_start(device_t dev, u_char slave, int timeout)
{
struct pcf_softc *sc = DEVTOSOFTC(dev);
int error = 0;
#ifdef PCFDEBUG
device_printf(dev, " >> start for slave %#x\n", (unsigned)slave);
#endif
if ((pcf_get_S1(sc) & nBB) == 0)
return (IIC_EBUSBSY);
/* set slave address to PCF. Last bit (LSB) must be set correctly
* according to transfer direction */
pcf_set_S0(sc, slave);
/* START only */
pcf_set_S1(sc, PIN|ESO|STA|ACK);
sc->pcf_started = 1;
/* wait for address sent, polling */
if ((error = pcf_wait_byte(sc)))
goto error;
/* check for ACK */
if (pcf_noack(sc, timeout)) {
error = IIC_ENOACK;
goto error;
}
return (0);
error:
pcf_stop(dev);
return (error);
}
void
pcf_intr(void *arg)
{
device_t dev = (device_t)arg;
struct pcf_softc *sc = DEVTOSOFTC(dev);
char data, status, addr;
char error = 0;
status = pcf_get_S1(sc);
if (status & PIN) {
device_printf(dev, "spurious interrupt, status=0x%x\n",
status & 0xff);
goto error;
}
if (status & LAB)
device_printf(dev, "bus arbitration lost!\n");
if (status & BER) {
error = IIC_EBUSERR;
iicbus_intr(sc->iicbus, INTR_ERROR, &error);
goto error;
}
do {
status = pcf_get_S1(sc);
switch(sc->pcf_slave_mode) {
case SLAVE_TRANSMITTER:
if (status & LRB) {
/* ack interrupt line */
dummy_write(sc);
/* no ack, don't send anymore */
sc->pcf_slave_mode = SLAVE_RECEIVER;
iicbus_intr(sc->iicbus, INTR_NOACK, NULL);
break;
}
/* get data from upper code */
iicbus_intr(sc->iicbus, INTR_TRANSMIT, &data);
pcf_set_S0(sc, data);
break;
case SLAVE_RECEIVER:
if (status & AAS) {
addr = pcf_get_S0(sc);
if (status & AD0)
iicbus_intr(sc->iicbus, INTR_GENERAL, &addr);
else
iicbus_intr(sc->iicbus, INTR_START, &addr);
if (addr & LSB) {
sc->pcf_slave_mode = SLAVE_TRANSMITTER;
/* get the first char from upper code */
iicbus_intr(sc->iicbus, INTR_TRANSMIT, &data);
/* send first data byte */
pcf_set_S0(sc, data);
}
break;
}
/* stop condition received? */
if (status & STS) {
/* ack interrupt line */
dummy_read(sc);
/* emulate intr stop condition */
iicbus_intr(sc->iicbus, INTR_STOP, NULL);
} else {
/* get data, ack interrupt line */
data = pcf_get_S0(sc);
/* deliver the character */
iicbus_intr(sc->iicbus, INTR_RECEIVE, &data);
}
break;
default:
panic("%s: unknown slave mode (%d)!", __func__,
sc->pcf_slave_mode);
}
} while ((pcf_get_S1(sc) & PIN) == 0);
return;
error:
/* unknown event on bus...reset PCF */
pcf_set_S1(sc, PIN|ESO|ENI|ACK);
sc->pcf_slave_mode = SLAVE_RECEIVER;
return;
}
int
pcf_rst_card(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
{
struct pcf_softc *sc = DEVTOSOFTC(dev);
if (oldaddr)
*oldaddr = sc->pcf_addr;
/* retrieve own address from bus level */
if (!addr)
sc->pcf_addr = PCF_DEFAULT_ADDR;
else
sc->pcf_addr = addr;
pcf_set_S1(sc, PIN); /* initialize S1 */
/* own address S'O<>0 */
pcf_set_S0(sc, sc->pcf_addr >> 1);
/* select clock register */
pcf_set_S1(sc, PIN|ES1);
/* select bus speed : 18=90kb, 19=45kb, 1A=11kb, 1B=1.5kb */
switch (speed) {
case IIC_SLOW:
pcf_set_S0(sc, 0x1b); /* XXX Sun uses 0x1f */
break;
case IIC_FAST:
pcf_set_S0(sc, 0x19); /* XXX Sun: 0x1d */
break;
case IIC_UNKNOWN:
case IIC_FASTEST:
default:
pcf_set_S0(sc, 0x18); /* XXX Sun: 0x1c */
break;
}
/* set bus on, ack=yes, INT=yes */
pcf_set_S1(sc, PIN|ESO|ENI|ACK);
sc->pcf_slave_mode = SLAVE_RECEIVER;
return (0);
}
int
pcf_write(device_t dev, char *buf, int len, int *sent, int timeout /* us */)
{
struct pcf_softc *sc = DEVTOSOFTC(dev);
int bytes, error = 0;
#ifdef PCFDEBUG
device_printf(dev, " >> writing %d bytes: %#x%s\n", len,
(unsigned)buf[0], len > 1? "...": "");
#endif
bytes = 0;
while (len) {
pcf_set_S0(sc, *buf++);
/* wait for the byte to be send */
if ((error = pcf_wait_byte(sc)))
goto error;
/* check if ack received */
if (pcf_noack(sc, timeout)) {
error = IIC_ENOACK;
goto error;
}
len --;
bytes ++;
}
error:
*sent = bytes;
#ifdef PCFDEBUG
device_printf(dev, " >> %d bytes written (%d)\n", bytes, error);
#endif
return (error);
}
int
pcf_read(device_t dev, char *buf, int len, int *read, int last,
int delay /* us */)
{
struct pcf_softc *sc = DEVTOSOFTC(dev);
int bytes, error = 0;
#ifdef PCFDEBUG
char *obuf = buf;
device_printf(dev, " << reading %d bytes\n", len);
#endif
/* trig the bus to get the first data byte in S0 */
if (len) {
if (len == 1 && last)
/* just one byte to read */
pcf_set_S1(sc, ESO); /* no ack */
dummy_read(sc);
}
bytes = 0;
while (len) {
/* XXX delay needed here */
/* wait for trigged byte */
if ((error = pcf_wait_byte(sc))) {
pcf_stop(dev);
goto error;
}
if (len == 1 && last)
/* ok, last data byte already in S0, no I2C activity
* on next pcf_get_S0() */
pcf_stop(dev);
else if (len == 2 && last)
/* next trigged byte with no ack */
pcf_set_S1(sc, ESO);
/* receive byte, trig next byte */
*buf++ = pcf_get_S0(sc);
len --;
bytes ++;
};
error:
*read = bytes;
#ifdef PCFDEBUG
device_printf(dev, " << %d bytes read (%d): %#x%s\n", bytes, error,
(unsigned)obuf[0], bytes > 1? "...": "");
#endif
return (error);
}