i2c: slave: rework the slave API

After more discussion, brave users, and additional datasheet evaluation,
some API updates for the new I2C slave framework became imminent. The
slave events now get some easier to understand naming. Also, the event
handling has been simplified to only need a single call to the slave
callback when an action by the backend is required.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
diff --git a/drivers/i2c/i2c-slave-eeprom.c b/drivers/i2c/i2c-slave-eeprom.c
index cf9b09d..3fb45d894 100644
--- a/drivers/i2c/i2c-slave-eeprom.c
+++ b/drivers/i2c/i2c-slave-eeprom.c
@@ -36,7 +36,7 @@
 	struct eeprom_data *eeprom = i2c_get_clientdata(client);
 
 	switch (event) {
-	case I2C_SLAVE_REQ_WRITE_END:
+	case I2C_SLAVE_WRITE_RECEIVED:
 		if (eeprom->first_write) {
 			eeprom->buffer_idx = *val;
 			eeprom->first_write = false;
@@ -47,17 +47,17 @@
 		}
 		break;
 
-	case I2C_SLAVE_REQ_READ_START:
+	case I2C_SLAVE_READ_PROCESSED:
+		eeprom->buffer_idx++;
+		/* fallthrough */
+	case I2C_SLAVE_READ_REQUESTED:
 		spin_lock(&eeprom->buffer_lock);
 		*val = eeprom->buffer[eeprom->buffer_idx];
 		spin_unlock(&eeprom->buffer_lock);
 		break;
 
-	case I2C_SLAVE_REQ_READ_END:
-		eeprom->buffer_idx++;
-		break;
-
 	case I2C_SLAVE_STOP:
+	case I2C_SLAVE_WRITE_REQUESTED:
 		eeprom->first_write = true;
 		break;