static void xilinx_spips_flush_txfifo(XilinxSPIPS *s) { int debug_level = 0; XilinxQSPIPS *q = (XilinxQSPIPS *) object_dynamic_cast(OBJECT(s), TYPE_XILINX_QSPIPS); for (;;) { int i; uint8_t tx = 0; uint8_t tx_rx[num_effective_busses(s)]; uint8_t dummy_cycles = 0; uint8_t addr_length; if (fifo8_is_empty(&s->tx_fifo)) { if (!(s->regs[R_LQSPI_CFG] & LQSPI_CFG_LQ_MODE)) { s->regs[R_INTR_STATUS] |= IXR_TX_FIFO_UNDERFLOW; } xilinx_spips_update_ixr(s); return; } else if (s->snoop_state == SNOOP_STRIPING) { for (i = 0; i < num_effective_busses(s); ++i) { tx_rx[i] = fifo8_pop(&s->tx_fifo); } stripe8(tx_rx, num_effective_busses(s), false); } else if (s->snoop_state >= SNOOP_ADDR) { tx = fifo8_pop(&s->tx_fifo); for (i = 0; i < num_effective_busses(s); ++i) { tx_rx[i] = tx; } } else { /* Extract a dummy byte and generate dummy cycles according to the * link state */ tx = fifo8_pop(&s->tx_fifo); dummy_cycles = 8 / s->link_state; } for (i = 0; i < num_effective_busses(s); ++i) { int bus = num_effective_busses(s) - 1 - i; if (dummy_cycles) { int d; for (d = 0; d < dummy_cycles; ++d) { tx_rx[0] = ssi_transfer(s->spi[bus], (uint32_t)tx_rx[0]); } } else { DB_PRINT_L(debug_level, "tx = %02x\n", tx_rx[i]); tx_rx[i] = ssi_transfer(s->spi[bus], (uint32_t)tx_rx[i]); DB_PRINT_L(debug_level, "rx = %02x\n", tx_rx[i]); } } if (s->regs[R_CMND] & R_CMND_RXFIFO_DRAIN) { DB_PRINT_L(debug_level, "dircarding drained rx byte\n"); /* Do nothing */ } else if (s->rx_discard) { DB_PRINT_L(debug_level, "dircarding discarded rx byte\n"); s->rx_discard -= 8 / s->link_state; } else if (fifo8_is_full(&s->rx_fifo)) { s->regs[R_INTR_STATUS] |= IXR_RX_FIFO_OVERFLOW; DB_PRINT_L(0, "rx FIFO overflow"); } else if (s->snoop_state == SNOOP_STRIPING) { stripe8(tx_rx, num_effective_busses(s), true); for (i = 0; i < num_effective_busses(s); ++i) { fifo8_push(&s->rx_fifo, (uint8_t)tx_rx[i]); DB_PRINT_L(debug_level, "pushing striped rx byte\n"); } } else { DB_PRINT_L(debug_level, "pushing unstriped rx byte\n"); fifo8_push(&s->rx_fifo, (uint8_t)tx_rx[0]); } if (s->link_state_next_when) { s->link_state_next_when--; if (!s->link_state_next_when) { s->link_state = s->link_state_next; } } DB_PRINT_L(debug_level, "initial snoop state: %x\n", (unsigned)s->snoop_state); switch (s->snoop_state) { case (SNOOP_CHECKING): /* Store the count of dummy bytes in the txfifo */ s->cmd_dummies = xilinx_spips_num_dummies(q, tx); addr_length = get_addr_length(s, tx); if (s->cmd_dummies < 0) { s->snoop_state = SNOOP_NONE; } else { s->snoop_state = SNOOP_ADDR + addr_length - 1; } switch (tx) { case DPP: case DOR: case DOR_4: s->link_state_next = 2; s->link_state_next_when = addr_length + s->cmd_dummies; break; case QPP: case QPP_4: case QOR: case QOR_4: s->link_state_next = 4; s->link_state_next_when = addr_length + s->cmd_dummies; break; case DIOR: case DIOR_4: s->link_state = 2; break; case QIOR: case QIOR_4: s->link_state = 4; break; } break; case (SNOOP_ADDR): /* Address has been transmitted, transmit dummy cycles now if * needed */ if (s->cmd_dummies < 0) { s->snoop_state = SNOOP_NONE; } else { s->snoop_state = s->cmd_dummies; } break; case (SNOOP_STRIPING): case (SNOOP_NONE): /* Once we hit the boring stuff - squelch debug noise */ if (!debug_level) { DB_PRINT_L(0, "squelching debug info ....\n"); debug_level = 1; } break; default: s->snoop_state--; } DB_PRINT_L(debug_level, "final snoop state: %x\n", (unsigned)s->snoop_state); } }