Commit 2eb9f241 authored by Marcus Comstedt's avatar Marcus Comstedt Committed by Andrzej Zaborowski
Browse files

bitbang_i2c: Fix spurious slave read after NACK 



After NACKing a read operation, a raising SCL should not trigger a new
read from the slave.  Introduce a new state which just waits for a stop
or start condition after NACK.

Signed-off-by: default avatarMarcus Comstedt <marcus@mc.pp.se>
Signed-off-by: default avatarAndrzej Zaborowski <andrew.zaborowski@intel.com>
parent 42a623c7

hw/bitbang_i2c.c

+4 −1
Original line number Diff line number Diff line
@@ -38,7 +38,8 @@ typedef enum bitbang_i2c_state { 
    RECEIVING_BIT2,

    RECEIVING_BIT1,

    RECEIVING_BIT0,

    SENDING_ACK

    SENDING_ACK,

    SENT_NACK

} bitbang_i2c_state;



struct bitbang_i2c_interface {
@@ -115,6 +116,7 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level) 
    }

    switch (i2c->state) {

    case STOPPED:

    case SENT_NACK:

        return bitbang_i2c_ret(i2c, 1);



    case SENDING_BIT7 ... SENDING_BIT0:
@@ -155,6 +157,7 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level) 
        i2c->state = RECEIVING_BIT7;

        if (data != 0) {

            DPRINTF("NACKED\n");

            i2c->state = SENT_NACK;

            i2c_nack(i2c->bus);

        } else {

            DPRINTF("ACKED\n");