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I2C overhaul part 4: VIA and EEPROM edition

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This commit is contained in:
RichardG867
2020-11-22 00:19:13 -03:00
parent d5867928d6
commit 3fb4727483
11 changed files with 313 additions and 129 deletions
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74
src/device/i2c_gpio.c
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@@ -39,6 +39,7 @@ enum {
I2C_TRANSMIT_START,
I2C_TRANSMIT,
I2C_ACKNOWLEDGE,
I2C_NEGACKNOWLEDGE,
I2C_TRANSACKNOWLEDGE,
I2C_TRANSMIT_WAIT
};
@@ -55,7 +56,7 @@ typedef struct {
char *bus_name;
void *i2c;
uint8_t scl, sda, state, slave_state, slave_addr,
slave_rw, last_sda, pos, transmit, byte;
slave_read, last_sda, pos, transmit, byte;
} i2c_gpio_t;
@@ -113,11 +114,11 @@ void
i2c_gpio_next_byte(i2c_gpio_t *dev)
{
dev->byte = i2c_read(dev->i2c, dev->slave_addr);
i2c_gpio_log(1, "I2C GPIO %s: next_byte() = %02X\n", dev->bus_name, dev->byte);
i2c_gpio_log(1, "I2C GPIO %s: Transmitting data %02X\n", dev->bus_name, dev->byte);
}
void
uint8_t
i2c_gpio_write(i2c_gpio_t *dev)
{
uint8_t i;
@@ -126,19 +127,20 @@ i2c_gpio_write(i2c_gpio_t *dev)
case SLAVE_IDLE:
i = dev->slave_addr;
dev->slave_addr = dev->byte >> 1;
dev->slave_rw = dev->byte & 1;
dev->slave_read = dev->byte & 1;
i2c_gpio_log(1, "I2C GPIO %s: Initiating transfer to address %02X rw %d\n", dev->bus_name, dev->slave_addr, dev->slave_rw);
i2c_gpio_log(1, "I2C GPIO %s: Initiating %s address %02X\n", dev->bus_name, dev->slave_read ? "read from" : "write to", dev->slave_addr);
if (!i2c_has_device(dev->i2c, dev->slave_addr)) {
dev->slave_state = SLAVE_INVALID;
break;
dev->slave_addr = 0xff;
return I2C_NEGACKNOWLEDGE;
}
if (i == 0xff)
i2c_start(dev->i2c, dev->slave_addr);
if (i == 0xff) /* start only once per transfer */
i2c_start(dev->i2c, dev->slave_addr, dev->slave_read);
if (dev->slave_rw) {
if (dev->slave_read) {
dev->slave_state = SLAVE_SENDDATA;
dev->transmit = TRANSMITTER_SLAVE;
dev->byte = i2c_read(dev->i2c, dev->slave_addr);
@@ -150,15 +152,22 @@ i2c_gpio_write(i2c_gpio_t *dev)
case SLAVE_RECEIVEADDR:
i2c_gpio_log(1, "I2C GPIO %s: Receiving address %02X\n", dev->bus_name, dev->byte);
i2c_write(dev->i2c, dev->slave_addr, dev->byte);
dev->slave_state = dev->slave_rw ? SLAVE_SENDDATA : SLAVE_RECEIVEDATA;
dev->slave_state = dev->slave_read ? SLAVE_SENDDATA : SLAVE_RECEIVEDATA;
if (!i2c_write(dev->i2c, dev->slave_addr, dev->byte))
return I2C_NEGACKNOWLEDGE;
break;
case SLAVE_RECEIVEDATA:
i2c_gpio_log(1, "I2C GPIO %s: Receiving data %02X\n", dev->bus_name, dev->byte);
i2c_write(dev->i2c, dev->slave_addr, dev->byte);
if (!i2c_write(dev->i2c, dev->slave_addr, dev->byte))
return I2C_NEGACKNOWLEDGE;
break;
case SLAVE_INVALID:
return I2C_NEGACKNOWLEDGE;
}
return I2C_ACKNOWLEDGE;
}
@@ -167,7 +176,7 @@ i2c_gpio_stop(i2c_gpio_t *dev)
{
i2c_gpio_log(1, "I2C GPIO %s: Stopping transfer\n", dev->bus_name);
if (dev->slave_addr != 0xff)
if (dev->slave_addr != 0xff) /* don't stop if no transfer was in progress */
i2c_stop(dev->i2c, dev->slave_addr);
dev->slave_addr = 0xff;
@@ -183,8 +192,8 @@ i2c_gpio_set(void *dev_handle, uint8_t scl, uint8_t sda)
switch (dev->state) {
case I2C_IDLE:
/* !dev->scl check breaks NCR SDMS. */
if (/*!dev->scl &&*/ scl && dev->last_sda && !sda) { /* start bit */
/* dev->scl check breaks NCR SDMS. */
if (scl && dev->last_sda && !sda) { /* start bit */
i2c_gpio_log(2, "I2C GPIO %s: Start bit received (from IDLE)\n", dev->bus_name);
dev->state = I2C_RECEIVE;
dev->pos = 0;
@@ -203,10 +212,8 @@ i2c_gpio_set(void *dev_handle, uint8_t scl, uint8_t sda)
dev->byte |= 1;
else
dev->byte &= 0xfe;
if (++dev->pos == 8) {
i2c_gpio_write(dev);
dev->state = I2C_ACKNOWLEDGE;
}
if (++dev->pos == 8)
dev->state = i2c_gpio_write(dev);
} else if (dev->scl && scl) {
if (sda && !dev->last_sda) { /* stop bit */
i2c_gpio_log(2, "I2C GPIO %s: Stop bit received (from RECEIVE)\n", dev->bus_name);
@@ -222,13 +229,23 @@ i2c_gpio_set(void *dev_handle, uint8_t scl, uint8_t sda)
case I2C_ACKNOWLEDGE:
if (!dev->scl && scl) {
i2c_gpio_log(2, "I2C GPIO %s: Acknowledging transfer\n", dev->bus_name);
i2c_gpio_log(2, "I2C GPIO %s: Acknowledging transfer to %02X\n", dev->bus_name, dev->slave_addr);
sda = 0;
dev->pos = 0;
dev->state = (dev->transmit == TRANSMITTER_MASTER) ? I2C_RECEIVE_WAIT : I2C_TRANSMIT;
}
break;
case I2C_NEGACKNOWLEDGE:
if (!dev->scl && scl) {
i2c_gpio_log(2, "I2C GPIO %s: Nacking transfer\n", dev->bus_name);
sda = 1;
dev->pos = 0;
dev->state = I2C_IDLE;
dev->slave_state = SLAVE_IDLE;
}
break;
case I2C_TRANSACKNOWLEDGE:
if (!dev->scl && scl) {
if (sda) { /* not acknowledged; must be end of transfer */
@@ -306,12 +323,17 @@ uint8_t
i2c_gpio_get_sda(void *dev_handle)
{
i2c_gpio_t *dev = (i2c_gpio_t *) dev_handle;
if ((dev->state == I2C_TRANSMIT) || (dev->state == I2C_ACKNOWLEDGE))
return dev->sda;
else if (dev->state == I2C_RECEIVE_WAIT)
return 0; /* ack */
else
return 1;
switch (dev->state) {
case I2C_TRANSMIT:
case I2C_ACKNOWLEDGE:
return dev->sda;
case I2C_RECEIVE_WAIT:
return 0; /* ack */
default:
return 1;
}
}