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",
;
/*
* 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
* 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.
*
* REVISIT: should probably use msleep instead of mdelay if we
* know we can sleep.
*/
if (adap->lab_mdelay)
mdelay(adap->lab_mdelay);
// DEB2(printk(KERN_INFO
// "i2c-algo-pcf.o: reset LAB condition (CSR 0x%02x)\n",
;
}
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));
/*
*/
set_pcf(adap, 1, I2C_PCF_PIN);
set_pcf(adap, 1, I2C_PCF_ESO);
/*
*/
if (adap->lab_mdelay)
mdelay(adap->lab_mdelay);
DEB2(printk(KERN_INFO
"i2c-algo-pcf.o: reset LAB condition (CSR 0x%02x)\n",
get_pcf(adap, 1)));
}
/*
* 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
* has been fulfilled.
* There should be a delay at the end equal to the longest I2C message
* to synchronize the BB-bit (in multimaster systems). How long is
* this? I assume 1 second is always long enough.
*
* vdovikin: added detect code for PCF8584
*/
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",
;
/* 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
*/
if (((temp = get_pcf(adap, 1)) & 0x7f) != (0)) {
;
return -ENXIO; /* definitely not PCF8584 */
}
/* 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)) {
;
return -ENXIO;
}
/* 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) {
;
return -ENXIO;
}
/* 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)) {
;
return -ENXIO;
}
/* 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 */
if ((temp = get_pcf(adap, 1)) != (I2C_PCF_PIN | I2C_PCF_BB)) {
;
return -ENXIO;
}
;
return 0;
}
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)));
/* */
set_pcf(adap, 1, I2C_PCF_PIN);
/*
*/
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; /* */
}
/* */
i2c_outb(adap, get_own(adap));
/* */
if ((temp = i2c_inb(adap)) != get_own(adap)) {
DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S0 (0x%02x).\n", temp));
return -ENXIO;
}
/* */
set_pcf(adap, 1, I2C_PCF_PIN | I2C_PCF_ES1);
/* */
if (((temp = get_pcf(adap, 1)) & 0x7f) != I2C_PCF_ES1) {
DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S2 (0x%02x).\n", temp));
return -ENXIO;
}
/* */
i2c_outb(adap, get_clock(adap));
/* */
if (((temp = i2c_inb(adap)) & 0x1f) != get_clock(adap)) {
DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S2 (0x%02x).\n", temp));
return -ENXIO;
}
/* */
set_pcf(adap, 1, I2C_PCF_IDLE);
/* */
if ((temp = get_pcf(adap, 1)) != (I2C_PCF_PIN | I2C_PCF_BB)) {
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;
}
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)) {
adap->waitforpin();
*status = get_pcf(adap, 1);
}
if (*status & I2C_PCF_LAB) {
DEB2(printk(KERN_INFO
"i2c-algo-pcf.o: lost arbitration (CSR 0x%02x)\n",
*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);
/* TODO: we should 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.
*/
DEB2(printk(KERN_INFO
"i2c-algo-pcf.o: reset LAB condition (CSR 0x%02x)\n",
get_pcf(adap,1)));
return(-EINTR);
}
#endif
if (timeout <= 0)
return(-1);
else
return(0);
}
static int pcf_readbytes(struct i2c_adapter *i2c_adap, char *buf,
int count, int last)
{
int i, status;
struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
int wfp;
/* increment number of bytes to read by one -- read dummy byte */
for (i = 0; i <= count; i++) {
if ((wfp = wait_for_pin(adap, &status))) {
if (wfp == -EINTR) {
/* arbitration lost */
return -EINTR;
}
i2c_stop(adap);
dev_err(&i2c_adap->dev, "pcf_readbytes timed out.\n");
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);
}
#endif
if (i == count - 1) {
set_pcf(adap, 1, I2C_PCF_ESO);
} else
if (i == count) {
if (last) {
i2c_stop(adap);
} else {
i2c_repstart(adap);
}
};
if (i) {
buf[i - 1] = i2c_inb(adap);
} else {
i2c_inb(adap); /* dummy read */
}
}
return (i - 1);
}
static int pcf_readbytes(struct i2c_adapter *i2c_adap, char *buf,
int count, int last)
{
int i, status;
struct i2c_algo_pcf_data *adap = i2c_adap->algo_data;
int wfp;
/* */
for (i = 0; i <= count; i++) {
if ((wfp = wait_for_pin(adap, &status))) {
if (wfp == -EINTR)
return -EINTR; /* */
i2c_stop(adap);
dev_err(&i2c_adap->dev, "pcf_readbytes timed out.\n");
return -1;
}
if ((status & I2C_PCF_LRB) && (i != count)) {
i2c_stop(adap);
dev_err(&i2c_adap->dev, "i2c_read: i2c_inb, No ack.\n");
return -1;
}
if (i == count - 1) {
set_pcf(adap, 1, I2C_PCF_ESO);
} else if (i == count) {
if (last)
i2c_stop(adap);
else
i2c_repstart(adap);
}
if (i)
buf[i - 1] = i2c_inb(adap);
else
i2c_inb(adap); /* */
}
return i - 1;
}
static void i2c_stop(struct i2c_algo_pcf_data *adap)
{
;
set_pcf(adap, 1, I2C_PCF_STOP);
}
static void i2c_repstart(struct i2c_algo_pcf_data *adap)
{
;
set_pcf(adap, 1, I2C_PCF_REPSTART);
}
static void i2c_stop(struct i2c_algo_pcf_data *adap)
{
DEBPROTO(printk("P\n"));
set_pcf(adap, 1, I2C_PCF_STOP);
}
static void i2c_repstart(struct i2c_algo_pcf_data *adap)
{
DEBPROTO(printk(" Sr "));
set_pcf(adap, 1, I2C_PCF_REPSTART);
}
static void i2c_start(struct i2c_algo_pcf_data *adap)
{
DEBPROTO(printk(KERN_DEBUG "S "));
set_pcf(adap, 1, I2C_PCF_START);
}
