/* Reprogram the Zilog channel HW registers with the copies found in the * software state struct. If the transmitter is busy, we defer this update * until the next TX complete interrupt. Else, we do it right now. * * The UART port lock must be held and local interrupts disabled. */ static void ip22zilog_maybe_update_regs(struct uart_ip22zilog_port *up, struct zilog_channel *channel) { if (!ZS_REGS_HELD(up)) { if (ZS_TX_ACTIVE(up)) { up->flags |= IP22ZILOG_FLAG_REGS_HELD; } else { __load_zsregs(channel, up->curregs); } } }
/* * We do like sunzilog to avoid disrupting pending Tx * Reprogram the Zilog channel HW registers with the copies found in the * software state struct. If the transmitter is busy, we defer this update * until the next TX complete interrupt. Else, we do it right now. * * The UART port lock must be held and local interrupts disabled. */ static void pmz_maybe_update_regs(struct uart_pmac_port *uap) { if (!ZS_REGS_HELD(uap)) { if (ZS_TX_ACTIVE(uap)) { uap->flags |= PMACZILOG_FLAG_REGS_HELD; } else { pmz_debug("pmz: maybe_update_regs: updating\n"); pmz_load_zsregs(uap, uap->curregs); } } }
static void ip22zilog_transmit_chars(struct uart_ip22zilog_port *up, struct zilog_channel *channel) { struct circ_buf *xmit; if (ZS_IS_CONS(up)) { unsigned char status = readb(&channel->control); ZSDELAY(); /* TX still busy? Just wait for the next TX done interrupt. * * It can occur because of how we do serial console writes. It would * be nice to transmit console writes just like we normally would for * a TTY line. (ie. buffered and TX interrupt driven). That is not * easy because console writes cannot sleep. One solution might be * to poll on enough port->xmit space becoming free. -DaveM */ if (!(status & Tx_BUF_EMP)) return; } up->flags &= ~IP22ZILOG_FLAG_TX_ACTIVE; if (ZS_REGS_HELD(up)) { __load_zsregs(channel, up->curregs); up->flags &= ~IP22ZILOG_FLAG_REGS_HELD; } if (ZS_TX_STOPPED(up)) { up->flags &= ~IP22ZILOG_FLAG_TX_STOPPED; goto ack_tx_int; } if (up->port.x_char) { up->flags |= IP22ZILOG_FLAG_TX_ACTIVE; writeb(up->port.x_char, &channel->data); ZSDELAY(); ZS_WSYNC(channel); up->port.icount.tx++; up->port.x_char = 0; return; } if (up->port.state == NULL) goto ack_tx_int; xmit = &up->port.state->xmit; if (uart_circ_empty(xmit)) goto ack_tx_int; if (uart_tx_stopped(&up->port)) goto ack_tx_int; up->flags |= IP22ZILOG_FLAG_TX_ACTIVE; writeb(xmit->buf[xmit->tail], &channel->data); ZSDELAY(); ZS_WSYNC(channel); xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); up->port.icount.tx++; if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&up->port); return; ack_tx_int: writeb(RES_Tx_P, &channel->control); ZSDELAY(); ZS_WSYNC(channel); }
static void pmz_transmit_chars(struct uart_pmac_port *uap) { struct circ_buf *xmit; if (ZS_IS_ASLEEP(uap)) return; if (ZS_IS_CONS(uap)) { unsigned char status = read_zsreg(uap, R0); /* TX still busy? Just wait for the next TX done interrupt. * * It can occur because of how we do serial console writes. It would * be nice to transmit console writes just like we normally would for * a TTY line. (ie. buffered and TX interrupt driven). That is not * easy because console writes cannot sleep. One solution might be * to poll on enough port->xmit space becomming free. -DaveM */ if (!(status & Tx_BUF_EMP)) return; } uap->flags &= ~PMACZILOG_FLAG_TX_ACTIVE; if (ZS_REGS_HELD(uap)) { pmz_load_zsregs(uap, uap->curregs); uap->flags &= ~PMACZILOG_FLAG_REGS_HELD; } if (ZS_TX_STOPPED(uap)) { uap->flags &= ~PMACZILOG_FLAG_TX_STOPPED; goto ack_tx_int; } if (uap->port.x_char) { uap->flags |= PMACZILOG_FLAG_TX_ACTIVE; write_zsdata(uap, uap->port.x_char); zssync(uap); uap->port.icount.tx++; uap->port.x_char = 0; return; } if (uap->port.info == NULL) goto ack_tx_int; xmit = &uap->port.info->xmit; if (uart_circ_empty(xmit)) { uart_write_wakeup(&uap->port); goto ack_tx_int; } if (uart_tx_stopped(&uap->port)) goto ack_tx_int; uap->flags |= PMACZILOG_FLAG_TX_ACTIVE; write_zsdata(uap, xmit->buf[xmit->tail]); zssync(uap); xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); uap->port.icount.tx++; if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&uap->port); return; ack_tx_int: write_zsreg(uap, R0, RES_Tx_P); zssync(uap); }