/*
* 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;
}
