diff options
Diffstat (limited to 'hw/i2c/bitbang_i2c.c')
| -rw-r--r-- | hw/i2c/bitbang_i2c.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/hw/i2c/bitbang_i2c.c b/hw/i2c/bitbang_i2c.c index d3a29891f8..8be88ee265 100644 --- a/hw/i2c/bitbang_i2c.c +++ b/hw/i2c/bitbang_i2c.c @@ -130,14 +130,25 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level) return bitbang_i2c_ret(i2c, 1); case WAITING_FOR_ACK: + { + int ret; + if (i2c->current_addr < 0) { i2c->current_addr = i2c->buffer; DPRINTF("Address 0x%02x\n", i2c->current_addr); - i2c_start_transfer(i2c->bus, i2c->current_addr >> 1, - i2c->current_addr & 1); + ret = i2c_start_transfer(i2c->bus, i2c->current_addr >> 1, + i2c->current_addr & 1); } else { DPRINTF("Sent 0x%02x\n", i2c->buffer); - i2c_send(i2c->bus, i2c->buffer); + ret = i2c_send(i2c->bus, i2c->buffer); + } + if (ret) { + /* NACK (either addressing a nonexistent device, or the + * device we were sending to decided to NACK us). + */ + DPRINTF("Got NACK\n"); + bitbang_i2c_enter_stop(i2c); + return bitbang_i2c_ret(i2c, 1); } if (i2c->current_addr & 1) { i2c->state = RECEIVING_BIT7; @@ -145,7 +156,7 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level) i2c->state = SENDING_BIT7; } return bitbang_i2c_ret(i2c, 0); - + } case RECEIVING_BIT7: i2c->buffer = i2c_recv(i2c->bus); DPRINTF("RX byte 0x%02x\n", i2c->buffer); |