diff options
Diffstat (limited to 'hw/i2c/bitbang_i2c.c')
-rw-r--r-- | hw/i2c/bitbang_i2c.c | 82 |
1 files changed, 51 insertions, 31 deletions
diff --git a/hw/i2c/bitbang_i2c.c b/hw/i2c/bitbang_i2c.c index e9a0612a04..bb18954765 100644 --- a/hw/i2c/bitbang_i2c.c +++ b/hw/i2c/bitbang_i2c.c @@ -16,30 +16,57 @@ #include "hw/sysbus.h" #include "qemu/module.h" #include "qom/object.h" +#include "trace.h" + + +/* bitbang_i2c_state enum to name */ +static const char * const sname[] = { +#define NAME(e) [e] = stringify(e) + NAME(STOPPED), + [SENDING_BIT7] = "SENDING_BIT7 (START)", + NAME(SENDING_BIT6), + NAME(SENDING_BIT5), + NAME(SENDING_BIT4), + NAME(SENDING_BIT3), + NAME(SENDING_BIT2), + NAME(SENDING_BIT1), + NAME(SENDING_BIT0), + NAME(WAITING_FOR_ACK), + [RECEIVING_BIT7] = "RECEIVING_BIT7 (ACK)", + NAME(RECEIVING_BIT6), + NAME(RECEIVING_BIT5), + NAME(RECEIVING_BIT4), + NAME(RECEIVING_BIT3), + NAME(RECEIVING_BIT2), + NAME(RECEIVING_BIT1), + NAME(RECEIVING_BIT0), + NAME(SENDING_ACK), + NAME(SENT_NACK) +#undef NAME +}; -//#define DEBUG_BITBANG_I2C - -#ifdef DEBUG_BITBANG_I2C -#define DPRINTF(fmt, ...) \ -do { printf("bitbang_i2c: " fmt , ## __VA_ARGS__); } while (0) -#else -#define DPRINTF(fmt, ...) do {} while(0) -#endif +static void bitbang_i2c_set_state(bitbang_i2c_interface *i2c, + bitbang_i2c_state state) +{ + trace_bitbang_i2c_state(sname[i2c->state], sname[state]); + i2c->state = state; +} static void bitbang_i2c_enter_stop(bitbang_i2c_interface *i2c) { - DPRINTF("STOP\n"); if (i2c->current_addr >= 0) i2c_end_transfer(i2c->bus); i2c->current_addr = -1; - i2c->state = STOPPED; + bitbang_i2c_set_state(i2c, STOPPED); } /* Set device data pin. */ static int bitbang_i2c_ret(bitbang_i2c_interface *i2c, int level) { + trace_bitbang_i2c_data(i2c->last_clock, i2c->last_data, + i2c->device_out, level); i2c->device_out = level; - //DPRINTF("%d %d %d\n", i2c->last_clock, i2c->last_data, i2c->device_out); + return level & i2c->last_data; } @@ -67,9 +94,8 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level) return bitbang_i2c_nop(i2c); } if (level == 0) { - DPRINTF("START\n"); /* START condition. */ - i2c->state = SENDING_BIT7; + bitbang_i2c_set_state(i2c, SENDING_BIT7); i2c->current_addr = -1; } else { /* STOP condition. */ @@ -96,7 +122,7 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level) case SENDING_BIT7 ... SENDING_BIT0: i2c->buffer = (i2c->buffer << 1) | data; /* will end up in WAITING_FOR_ACK */ - i2c->state++; + bitbang_i2c_set_state(i2c, i2c->state + 1); return bitbang_i2c_ret(i2c, 1); case WAITING_FOR_ACK: @@ -105,47 +131,45 @@ int bitbang_i2c_set(bitbang_i2c_interface *i2c, int line, int level) if (i2c->current_addr < 0) { i2c->current_addr = i2c->buffer; - DPRINTF("Address 0x%02x\n", i2c->current_addr); + trace_bitbang_i2c_addr(i2c->current_addr); ret = i2c_start_transfer(i2c->bus, i2c->current_addr >> 1, i2c->current_addr & 1); } else { - DPRINTF("Sent 0x%02x\n", i2c->buffer); + trace_bitbang_i2c_send(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_set_state(i2c, SENT_NACK); bitbang_i2c_enter_stop(i2c); return bitbang_i2c_ret(i2c, 1); } if (i2c->current_addr & 1) { - i2c->state = RECEIVING_BIT7; + bitbang_i2c_set_state(i2c, RECEIVING_BIT7); } else { - i2c->state = SENDING_BIT7; + bitbang_i2c_set_state(i2c, 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); + trace_bitbang_i2c_recv(i2c->buffer); /* Fall through... */ case RECEIVING_BIT6 ... RECEIVING_BIT0: data = i2c->buffer >> 7; /* will end up in SENDING_ACK */ - i2c->state++; + bitbang_i2c_set_state(i2c, i2c->state + 1); i2c->buffer <<= 1; return bitbang_i2c_ret(i2c, data); case SENDING_ACK: - i2c->state = RECEIVING_BIT7; if (data != 0) { - DPRINTF("NACKED\n"); - i2c->state = SENT_NACK; + bitbang_i2c_set_state(i2c, SENT_NACK); i2c_nack(i2c->bus); } else { - DPRINTF("ACKED\n"); + bitbang_i2c_set_state(i2c, RECEIVING_BIT7); } return bitbang_i2c_ret(i2c, 1); } @@ -162,13 +186,13 @@ void bitbang_i2c_init(bitbang_i2c_interface *s, I2CBus *bus) /* GPIO interface. */ -#define TYPE_GPIO_I2C "gpio_i2c" OBJECT_DECLARE_SIMPLE_TYPE(GPIOI2CState, GPIO_I2C) struct GPIOI2CState { + /*< private >*/ SysBusDevice parent_obj; + /*< public >*/ - MemoryRegion dummy_iomem; bitbang_i2c_interface bitbang; int last_level; qemu_irq out; @@ -189,12 +213,8 @@ static void gpio_i2c_init(Object *obj) { DeviceState *dev = DEVICE(obj); GPIOI2CState *s = GPIO_I2C(obj); - SysBusDevice *sbd = SYS_BUS_DEVICE(obj); I2CBus *bus; - memory_region_init(&s->dummy_iomem, obj, "gpio_i2c", 0); - sysbus_init_mmio(sbd, &s->dummy_iomem); - bus = i2c_init_bus(dev, "i2c"); bitbang_i2c_init(&s->bitbang, bus); |