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/* $OpenBSD: sociic.c,v 1.1 2008/05/10 12:02:21 kettenis Exp $ */
/*
* Copyright (c) 2008 Mark Kettenis
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* Driver for the I2C interface on the MPC8349E processors.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/rwlock.h>
#include <machine/autoconf.h>
#include <machine/bus.h>
#include <dev/i2c/i2cvar.h>
#define I2C_ADR 0x00 /* Address Register */
#define I2C_FDR 0x04 /* Fequency Divider Register */
#define I2C_CR 0x08 /* Control Register */
#define I2C_CR_MEN 0x80
#define I2C_CR_MIEN 0x40
#define I2C_CR_MSTA 0x20
#define I2C_CR_MTX 0x10
#define I2C_CR_TXAK 0x08
#define I2C_CR_RSTA 0x04
#define I2C_CR_BCST 0x01
#define I2C_SR 0x0c /* Status Register */
#define I2C_SR_MCF 0x80
#define I2C_SR_MAAS 0x40
#define I2C_SR_MBB 0x20
#define I2C_SR_MAL 0x10
#define I2C_SR_BCSTM 0x08
#define I2C_SR_SRW 0x04
#define I2C_SR_MIF 0x02
#define I2C_SR_RXAK 0x01
#define I2C_DR 0x10 /* Data Register */
#define I2C_DFSRR 0x14 /* Digital Filter Sampling Rate Register */
struct sociic_softc {
struct device sc_dev;
bus_space_tag_t sc_iot;
bus_space_handle_t sc_ioh;
struct i2c_controller sc_i2c;
struct rwlock sc_lock;
};
int sociic_match(struct device *, void *, void *);
void sociic_attach(struct device *, struct device *, void *);
struct cfattach sociic_ca = {
sizeof(struct sociic_softc), sociic_match, sociic_attach
};
struct cfdriver sociic_cd = {
NULL, "sociic", DV_DULL
};
void sociic_write(struct sociic_softc *, bus_addr_t, uint8_t);
uint8_t sociic_read(struct sociic_softc *, bus_addr_t);
int sociic_wait(struct sociic_softc *, int);
int sociic_wait_bus(struct sociic_softc *);
int sociic_i2c_acquire_bus(void *, int);
void sociic_i2c_release_bus(void *, int);
int sociic_i2c_exec(void *, i2c_op_t, i2c_addr_t,
const void *, size_t, void *, size_t, int);
int
sociic_match(struct device *parent, void *cfdata, void *aux)
{
return (1);
}
void
sociic_attach(struct device *parent, struct device *self, void *aux)
{
struct sociic_softc *sc = (void *)self;
struct obio_attach_args *oa = aux;
struct i2cbus_attach_args iba;
sc->sc_iot = oa->oa_iot;
if (bus_space_map(sc->sc_iot, oa->oa_offset, 24, 0, &sc->sc_ioh)) {
printf(": can't map registers\n");
return;
}
printf("\n");
rw_init(&sc->sc_lock, "iiclk");
sc->sc_i2c.ic_cookie = sc;
sc->sc_i2c.ic_acquire_bus = sociic_i2c_acquire_bus;
sc->sc_i2c.ic_release_bus = sociic_i2c_release_bus;
sc->sc_i2c.ic_exec = sociic_i2c_exec;
bzero(&iba, sizeof iba);
iba.iba_name = "iic";
iba.iba_tag = &sc->sc_i2c;
config_found(&sc->sc_dev, &iba, iicbus_print);
}
void
sociic_write(struct sociic_softc *sc, bus_addr_t addr, uint8_t data)
{
bus_space_write_1(sc->sc_iot, sc->sc_ioh, addr, data);
}
uint8_t
sociic_read(struct sociic_softc *sc, bus_addr_t addr)
{
return (bus_space_read_1(sc->sc_iot, sc->sc_ioh, addr));
}
int
sociic_wait(struct sociic_softc *sc, int flags)
{
uint8_t sr;
int i;
for (i = 0; i < 1000; i++) {
sr = sociic_read(sc, I2C_SR);
if (sr & I2C_SR_MIF) {
sociic_write(sc, I2C_SR, 0);
if (sr & I2C_SR_MAL)
return (EIO);
if ((sr & I2C_SR_MCF) == 0)
return (EIO);
if ((flags & I2C_F_READ) == 0 && (sr & I2C_SR_RXAK))
return (EIO);
return (0);
}
delay(100);
}
return (ETIMEDOUT);
}
int
sociic_wait_bus(struct sociic_softc *sc)
{
uint8_t sr;
int i;
for (i = 0; i < 1000; i++) {
sr = sociic_read(sc, I2C_SR);
if ((sr & I2C_SR_MBB) == 0)
return (0);
delay(1000);
}
return (ETIMEDOUT);
}
int
sociic_i2c_acquire_bus(void *arg, int flags)
{
struct sociic_softc *sc = arg;
if (cold || (flags & I2C_F_POLL))
return (0);
return (rw_enter(&sc->sc_lock, RW_WRITE | RW_INTR));
}
void
sociic_i2c_release_bus(void *arg, int flags)
{
struct sociic_softc *sc = arg;
if (cold || (flags & I2C_F_POLL))
return;
rw_exit(&sc->sc_lock);
}
int
sociic_i2c_exec(void *arg, i2c_op_t op, i2c_addr_t addr,
const void *vcmdbuf, size_t cmdlen, void *vbuf, size_t buflen, int flags)
{
struct sociic_softc *sc = arg;
const uint8_t *cmdbuf = vcmdbuf;
uint8_t *buf = vbuf;
int err = 0;
size_t len;
uint8_t val;
/* Clear the bus. */
sociic_write(sc, I2C_SR, 0);
sociic_write(sc, I2C_CR, I2C_CR_MEN);
err = sociic_wait_bus(sc);
if (err)
return (err);
if (cmdlen > 0) {
sociic_write(sc, I2C_CR, I2C_CR_MEN|I2C_CR_MSTA|I2C_CR_MTX);
sociic_write(sc, I2C_DR, addr << 1);
err = sociic_wait(sc, I2C_F_WRITE);
if (err)
goto out;
len = cmdlen;
while (len--) {
sociic_write(sc, I2C_DR, *cmdbuf++);
err = sociic_wait(sc, I2C_F_WRITE);
if (err)
goto out;
}
}
if (I2C_OP_READ_P(op) && buflen > 0) {
/* RESTART if we did write a command above. */
val = I2C_CR_MEN|I2C_CR_MSTA|I2C_CR_MTX;
if (cmdlen > 0)
val |= I2C_CR_RSTA;
sociic_write(sc, I2C_CR, val);
sociic_write(sc, I2C_DR, (addr << 1) | 1);
err = sociic_wait(sc, I2C_F_WRITE);
if (err)
goto out;
/* NACK if we're only sending one byte. */
val = I2C_CR_MEN|I2C_CR_MSTA;
if (buflen == 1)
val |= I2C_CR_TXAK;
sociic_write(sc, I2C_CR, val);
/* Dummy read. */
sociic_read(sc, I2C_DR);
len = buflen;
while (len--) {
err = sociic_wait(sc, I2C_F_READ);
if (err)
goto out;
/* NACK on last byte. */
if (len == 1)
sociic_write(sc, I2C_CR,
I2C_CR_MEN|I2C_CR_MSTA|I2C_CR_TXAK);
/* STOP after last byte. */
if (len == 0)
sociic_write(sc, I2C_CR,
I2C_CR_MEN|I2C_CR_TXAK);
*buf++ = sociic_read(sc, I2C_DR);
}
}
if (I2C_OP_WRITE_P(op) && cmdlen == 0 && buflen > 0) {
/* START if we didn't write a command. */
sociic_write(sc, I2C_CR, I2C_CR_MEN|I2C_CR_MSTA|I2C_CR_MTX);
sociic_write(sc, I2C_DR, addr << 1);
err = sociic_wait(sc, I2C_F_WRITE);
if (err)
goto out;
}
if (I2C_OP_WRITE_P(op) && buflen > 0) {
len = buflen;
while (len--) {
sociic_write(sc, I2C_DR, *buf++);
err = sociic_wait(sc, I2C_F_WRITE);
if (err)
goto out;
}
}
out:
/* STOP if we're still holding the bus. */
sociic_write(sc, I2C_CR, I2C_CR_MEN);
return (err);
}
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