/*- * SPDX-License-Identifier: BSD-2-Clause AND BSD-2-Clause * * Copyright (c) 2003 Marcel Moolenaar * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* * uart_dev_oct16550.c * * Derived from uart_dev_ns8250.c * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include "uart_if.h" /* * Clear pending interrupts. THRE is cleared by reading IIR. Data * that may have been received gets lost here. */ static void oct16550_clrint (struct uart_bas *bas) { uint8_t iir; iir = uart_getreg(bas, REG_IIR); while ((iir & IIR_NOPEND) == 0) { iir &= IIR_IMASK; if (iir == IIR_RLS) (void)uart_getreg(bas, REG_LSR); else if (iir == IIR_RXRDY || iir == IIR_RXTOUT) (void)uart_getreg(bas, REG_DATA); else if (iir == IIR_MLSC) (void)uart_getreg(bas, REG_MSR); else if (iir == IIR_BUSY) (void) uart_getreg(bas, REG_USR); uart_barrier(bas); iir = uart_getreg(bas, REG_IIR); } } static int delay_changed = 1; static int oct16550_delay (struct uart_bas *bas) { int divisor; u_char lcr; static int delay = 0; if (!delay_changed) return delay; delay_changed = 0; lcr = uart_getreg(bas, REG_LCR); uart_setreg(bas, REG_LCR, lcr | LCR_DLAB); uart_barrier(bas); divisor = uart_getreg(bas, REG_DLL) | (uart_getreg(bas, REG_DLH) << 8); uart_barrier(bas); uart_setreg(bas, REG_LCR, lcr); uart_barrier(bas); if(!bas->rclk) return 10; /* return an approx delay value */ /* 1/10th the time to transmit 1 character (estimate). */ if (divisor <= 134) return (16000000 * divisor / bas->rclk); return (16000 * divisor / (bas->rclk / 1000)); } static int oct16550_divisor (int rclk, int baudrate) { int actual_baud, divisor; int error; if (baudrate == 0) return (0); divisor = (rclk / (baudrate << 3) + 1) >> 1; if (divisor == 0 || divisor >= 65536) return (0); actual_baud = rclk / (divisor << 4); /* 10 times error in percent: */ error = ((actual_baud - baudrate) * 2000 / baudrate + 1) >> 1; /* 3.0% maximum error tolerance: */ if (error < -30 || error > 30) return (0); return (divisor); } static int oct16550_drain (struct uart_bas *bas, int what) { int delay, limit; delay = oct16550_delay(bas); if (what & UART_DRAIN_TRANSMITTER) { /* * Pick an arbitrary high limit to avoid getting stuck in * an infinite loop when the hardware is broken. Make the * limit high enough to handle large FIFOs. */ limit = 10*10*10*1024; while ((uart_getreg(bas, REG_LSR) & LSR_TEMT) == 0 && --limit) DELAY(delay); if (limit == 0) { /* printf("oct16550: transmitter appears stuck... "); */ return (0); } } if (what & UART_DRAIN_RECEIVER) { /* * Pick an arbitrary high limit to avoid getting stuck in * an infinite loop when the hardware is broken. Make the * limit high enough to handle large FIFOs and integrated * UARTs. The HP rx2600 for example has 3 UARTs on the * management board that tend to get a lot of data send * to it when the UART is first activated. */ limit=10*4096; while ((uart_getreg(bas, REG_LSR) & LSR_RXRDY) && --limit) { (void)uart_getreg(bas, REG_DATA); uart_barrier(bas); DELAY(delay << 2); } if (limit == 0) { /* printf("oct16550: receiver appears broken... "); */ return (EIO); } } return (0); } /* * We can only flush UARTs with FIFOs. UARTs without FIFOs should be * drained. WARNING: this function clobbers the FIFO setting! */ static void oct16550_flush (struct uart_bas *bas, int what) { uint8_t fcr; fcr = FCR_ENABLE; if (what & UART_FLUSH_TRANSMITTER) fcr |= FCR_XMT_RST; if (what & UART_FLUSH_RECEIVER) fcr |= FCR_RCV_RST; uart_setreg(bas, REG_FCR, fcr); uart_barrier(bas); } static int oct16550_param (struct uart_bas *bas, int baudrate, int databits, int stopbits, int parity) { int divisor; uint8_t lcr; lcr = 0; if (databits >= 8) lcr |= LCR_8BITS; else if (databits == 7) lcr |= LCR_7BITS; else if (databits == 6) lcr |= LCR_6BITS; else lcr |= LCR_5BITS; if (stopbits > 1) lcr |= LCR_STOPB; lcr |= parity << 3; /* Set baudrate. */ if (baudrate > 0) { divisor = oct16550_divisor(bas->rclk, baudrate); if (divisor == 0) return (EINVAL); uart_setreg(bas, REG_LCR, lcr | LCR_DLAB); uart_barrier(bas); uart_setreg(bas, REG_DLL, divisor & 0xff); uart_setreg(bas, REG_DLH, (divisor >> 8) & 0xff); uart_barrier(bas); delay_changed = 1; } /* Set LCR and clear DLAB. */ uart_setreg(bas, REG_LCR, lcr); uart_barrier(bas); return (0); } /* * Low-level UART interface. */ static int oct16550_probe(struct uart_bas *bas); static void oct16550_init(struct uart_bas *bas, int, int, int, int); static void oct16550_term(struct uart_bas *bas); static void oct16550_putc(struct uart_bas *bas, int); static int oct16550_rxready(struct uart_bas *bas); static int oct16550_getc(struct uart_bas *bas, struct mtx *); struct uart_ops uart_oct16550_ops = { .probe = oct16550_probe, .init = oct16550_init, .term = oct16550_term, .putc = oct16550_putc, .rxready = oct16550_rxready, .getc = oct16550_getc, }; static int oct16550_probe (struct uart_bas *bas) { u_char val; /* Check known 0 bits that don't depend on DLAB. */ val = uart_getreg(bas, REG_IIR); if (val & 0x30) return (ENXIO); val = uart_getreg(bas, REG_MCR); if (val & 0xc0) return (ENXIO); val = uart_getreg(bas, REG_USR); if (val & 0xe0) return (ENXIO); return (0); } static void oct16550_init (struct uart_bas *bas, int baudrate, int databits, int stopbits, int parity) { u_char ier; oct16550_param(bas, baudrate, databits, stopbits, parity); /* Disable all interrupt sources. */ ier = uart_getreg(bas, REG_IER) & 0x0; uart_setreg(bas, REG_IER, ier); uart_barrier(bas); /* Disable the FIFO (if present). */ // uart_setreg(bas, REG_FCR, 0); uart_barrier(bas); /* Set RTS & DTR. */ uart_setreg(bas, REG_MCR, MCR_RTS | MCR_DTR); uart_barrier(bas); oct16550_clrint(bas); } static void oct16550_term (struct uart_bas *bas) { /* Clear RTS & DTR. */ uart_setreg(bas, REG_MCR, 0); uart_barrier(bas); } static inline void oct16550_wait_txhr_empty (struct uart_bas *bas, int limit, int delay) { while (((uart_getreg(bas, REG_LSR) & LSR_THRE) == 0) && ((uart_getreg(bas, REG_USR) & USR_TXFIFO_NOTFULL) == 0)) DELAY(delay); } static void oct16550_putc (struct uart_bas *bas, int c) { int delay; /* 1/10th the time to transmit 1 character (estimate). */ delay = oct16550_delay(bas); oct16550_wait_txhr_empty(bas, 100, delay); uart_setreg(bas, REG_DATA, c); uart_barrier(bas); oct16550_wait_txhr_empty(bas, 100, delay); } static int oct16550_rxready (struct uart_bas *bas) { return ((uart_getreg(bas, REG_LSR) & LSR_RXRDY) != 0 ? 1 : 0); } static int oct16550_getc (struct uart_bas *bas, struct mtx *hwmtx) { int c, delay; uart_lock(hwmtx); /* 1/10th the time to transmit 1 character (estimate). */ delay = oct16550_delay(bas); while ((uart_getreg(bas, REG_LSR) & LSR_RXRDY) == 0) { uart_unlock(hwmtx); DELAY(delay); uart_lock(hwmtx); } c = uart_getreg(bas, REG_DATA); uart_unlock(hwmtx); return (c); } /* * High-level UART interface. */ struct oct16550_softc { struct uart_softc base; uint8_t fcr; uint8_t ier; uint8_t mcr; }; static int oct16550_bus_attach(struct uart_softc *); static int oct16550_bus_detach(struct uart_softc *); static int oct16550_bus_flush(struct uart_softc *, int); static int oct16550_bus_getsig(struct uart_softc *); static int oct16550_bus_ioctl(struct uart_softc *, int, intptr_t); static int oct16550_bus_ipend(struct uart_softc *); static int oct16550_bus_param(struct uart_softc *, int, int, int, int); static int oct16550_bus_probe(struct uart_softc *); static int oct16550_bus_receive(struct uart_softc *); static int oct16550_bus_setsig(struct uart_softc *, int); static int oct16550_bus_transmit(struct uart_softc *); static bool oct16550_bus_txbusy(struct uart_softc *); static void oct16550_bus_grab(struct uart_softc *); static void oct16550_bus_ungrab(struct uart_softc *); static kobj_method_t oct16550_methods[] = { KOBJMETHOD(uart_attach, oct16550_bus_attach), KOBJMETHOD(uart_detach, oct16550_bus_detach), KOBJMETHOD(uart_flush, oct16550_bus_flush), KOBJMETHOD(uart_getsig, oct16550_bus_getsig), KOBJMETHOD(uart_ioctl, oct16550_bus_ioctl), KOBJMETHOD(uart_ipend, oct16550_bus_ipend), KOBJMETHOD(uart_param, oct16550_bus_param), KOBJMETHOD(uart_probe, oct16550_bus_probe), KOBJMETHOD(uart_receive, oct16550_bus_receive), KOBJMETHOD(uart_setsig, oct16550_bus_setsig), KOBJMETHOD(uart_transmit, oct16550_bus_transmit), KOBJMETHOD(uart_txbusy, oct16550_bus_txbusy), KOBJMETHOD(uart_grab, oct16550_bus_grab), KOBJMETHOD(uart_ungrab, oct16550_bus_ungrab), KOBJMETHOD_END }; struct uart_class uart_oct16550_class = { "oct16550 class", oct16550_methods, sizeof(struct oct16550_softc), .uc_ops = &uart_oct16550_ops, .uc_range = 8 << 3, .uc_rclk = 0, .uc_rshift = 0 }; #define SIGCHG(c, i, s, d) \ if (c) { \ i |= (i & s) ? s : s | d; \ } else { \ i = (i & s) ? (i & ~s) | d : i; \ } static int oct16550_bus_attach (struct uart_softc *sc) { struct oct16550_softc *oct16550 = (struct oct16550_softc*)sc; struct uart_bas *bas; int unit; unit = device_get_unit(sc->sc_dev); bas = &sc->sc_bas; oct16550_drain(bas, UART_DRAIN_TRANSMITTER); oct16550->mcr = uart_getreg(bas, REG_MCR); oct16550->fcr = FCR_ENABLE | FCR_RX_HIGH; uart_setreg(bas, REG_FCR, oct16550->fcr); uart_barrier(bas); oct16550_bus_flush(sc, UART_FLUSH_RECEIVER|UART_FLUSH_TRANSMITTER); if (oct16550->mcr & MCR_DTR) sc->sc_hwsig |= SER_DTR; if (oct16550->mcr & MCR_RTS) sc->sc_hwsig |= SER_RTS; oct16550_bus_getsig(sc); oct16550_clrint(bas); oct16550->ier = uart_getreg(bas, REG_IER) & 0xf0; oct16550->ier |= IER_EMSC | IER_ERLS | IER_ERXRDY; uart_setreg(bas, REG_IER, oct16550->ier); uart_barrier(bas); return (0); } static int oct16550_bus_detach (struct uart_softc *sc) { struct uart_bas *bas; u_char ier; bas = &sc->sc_bas; ier = uart_getreg(bas, REG_IER) & 0xf0; uart_setreg(bas, REG_IER, ier); uart_barrier(bas); oct16550_clrint(bas); return (0); } static int oct16550_bus_flush (struct uart_softc *sc, int what) { struct oct16550_softc *oct16550 = (struct oct16550_softc*)sc; struct uart_bas *bas; int error; bas = &sc->sc_bas; uart_lock(sc->sc_hwmtx); if (sc->sc_rxfifosz > 1) { oct16550_flush(bas, what); uart_setreg(bas, REG_FCR, oct16550->fcr); uart_barrier(bas); error = 0; } else error = oct16550_drain(bas, what); uart_unlock(sc->sc_hwmtx); return (error); } static int oct16550_bus_getsig (struct uart_softc *sc) { uint32_t new, old, sig; uint8_t msr; do { old = sc->sc_hwsig; sig = old; uart_lock(sc->sc_hwmtx); msr = uart_getreg(&sc->sc_bas, REG_MSR); uart_unlock(sc->sc_hwmtx); SIGCHG(msr & MSR_DSR, sig, SER_DSR, SER_DDSR); SIGCHG(msr & MSR_CTS, sig, SER_CTS, SER_DCTS); SIGCHG(msr & MSR_DCD, sig, SER_DCD, SER_DDCD); SIGCHG(msr & MSR_RI, sig, SER_RI, SER_DRI); new = sig & ~SER_MASK_DELTA; } while (!atomic_cmpset_32(&sc->sc_hwsig, old, new)); return (sig); } static int oct16550_bus_ioctl (struct uart_softc *sc, int request, intptr_t data) { struct uart_bas *bas; int baudrate, divisor, error; uint8_t efr, lcr; bas = &sc->sc_bas; error = 0; uart_lock(sc->sc_hwmtx); switch (request) { case UART_IOCTL_BREAK: lcr = uart_getreg(bas, REG_LCR); if (data) lcr |= LCR_SBREAK; else lcr &= ~LCR_SBREAK; uart_setreg(bas, REG_LCR, lcr); uart_barrier(bas); break; case UART_IOCTL_IFLOW: lcr = uart_getreg(bas, REG_LCR); uart_barrier(bas); uart_setreg(bas, REG_LCR, 0xbf); uart_barrier(bas); efr = uart_getreg(bas, REG_EFR); if (data) efr |= EFR_RTS; else efr &= ~EFR_RTS; uart_setreg(bas, REG_EFR, efr); uart_barrier(bas); uart_setreg(bas, REG_LCR, lcr); uart_barrier(bas); break; case UART_IOCTL_OFLOW: lcr = uart_getreg(bas, REG_LCR); uart_barrier(bas); uart_setreg(bas, REG_LCR, 0xbf); uart_barrier(bas); efr = uart_getreg(bas, REG_EFR); if (data) efr |= EFR_CTS; else efr &= ~EFR_CTS; uart_setreg(bas, REG_EFR, efr); uart_barrier(bas); uart_setreg(bas, REG_LCR, lcr); uart_barrier(bas); break; case UART_IOCTL_BAUD: lcr = uart_getreg(bas, REG_LCR); uart_setreg(bas, REG_LCR, lcr | LCR_DLAB); uart_barrier(bas); divisor = uart_getreg(bas, REG_DLL) | (uart_getreg(bas, REG_DLH) << 8); uart_barrier(bas); uart_setreg(bas, REG_LCR, lcr); uart_barrier(bas); baudrate = (divisor > 0) ? bas->rclk / divisor / 16 : 0; delay_changed = 1; if (baudrate > 0) *(int*)data = baudrate; else error = ENXIO; break; default: error = EINVAL; break; } uart_unlock(sc->sc_hwmtx); return (error); } static int oct16550_bus_ipend(struct uart_softc *sc) { struct uart_bas *bas; int ipend = 0; uint8_t iir, lsr; bas = &sc->sc_bas; uart_lock(sc->sc_hwmtx); iir = uart_getreg(bas, REG_IIR) & IIR_IMASK; if (iir != IIR_NOPEND) { if (iir == IIR_RLS) { lsr = uart_getreg(bas, REG_LSR); if (lsr & LSR_OE) ipend |= SER_INT_OVERRUN; if (lsr & LSR_BI) ipend |= SER_INT_BREAK; if (lsr & LSR_RXRDY) ipend |= SER_INT_RXREADY; } else if (iir == IIR_RXRDY) { ipend |= SER_INT_RXREADY; } else if (iir == IIR_RXTOUT) { ipend |= SER_INT_RXREADY; } else if (iir == IIR_TXRDY) { ipend |= SER_INT_TXIDLE; } else if (iir == IIR_MLSC) { ipend |= SER_INT_SIGCHG; } else if (iir == IIR_BUSY) { (void) uart_getreg(bas, REG_USR); } } uart_unlock(sc->sc_hwmtx); return (ipend); } static int oct16550_bus_param (struct uart_softc *sc, int baudrate, int databits, int stopbits, int parity) { struct uart_bas *bas; int error; bas = &sc->sc_bas; uart_lock(sc->sc_hwmtx); error = oct16550_param(bas, baudrate, databits, stopbits, parity); uart_unlock(sc->sc_hwmtx); return (error); } static int oct16550_bus_probe (struct uart_softc *sc) { struct uart_bas *bas; int error; bas = &sc->sc_bas; bas->rclk = uart_oct16550_class.uc_rclk = cvmx_clock_get_rate(CVMX_CLOCK_SCLK); error = oct16550_probe(bas); if (error) { return (error); } uart_setreg(bas, REG_MCR, (MCR_DTR | MCR_RTS)); /* * Enable FIFOs. And check that the UART has them. If not, we're * done. Since this is the first time we enable the FIFOs, we reset * them. */ oct16550_drain(bas, UART_DRAIN_TRANSMITTER); #define ENABLE_OCTEON_FIFO 1 #ifdef ENABLE_OCTEON_FIFO uart_setreg(bas, REG_FCR, FCR_ENABLE | FCR_XMT_RST | FCR_RCV_RST); #endif uart_barrier(bas); oct16550_flush(bas, UART_FLUSH_RECEIVER|UART_FLUSH_TRANSMITTER); if (device_get_unit(sc->sc_dev)) { device_set_desc(sc->sc_dev, "Octeon-16550 channel 1"); } else { device_set_desc(sc->sc_dev, "Octeon-16550 channel 0"); } #ifdef ENABLE_OCTEON_FIFO sc->sc_rxfifosz = 64; sc->sc_txfifosz = 64; #else sc->sc_rxfifosz = 1; sc->sc_txfifosz = 1; #endif #if 0 /* * XXX there are some issues related to hardware flow control and * it's likely that uart(4) is the cause. This basicly needs more * investigation, but we avoid using for hardware flow control * until then. */ /* 16650s or higher have automatic flow control. */ if (sc->sc_rxfifosz > 16) { sc->sc_hwiflow = 1; sc->sc_hwoflow = 1; } #endif return (0); } static int oct16550_bus_receive (struct uart_softc *sc) { struct uart_bas *bas; int xc; uint8_t lsr; bas = &sc->sc_bas; uart_lock(sc->sc_hwmtx); lsr = uart_getreg(bas, REG_LSR); while (lsr & LSR_RXRDY) { if (uart_rx_full(sc)) { sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN; break; } xc = uart_getreg(bas, REG_DATA); if (lsr & LSR_FE) xc |= UART_STAT_FRAMERR; if (lsr & LSR_PE) xc |= UART_STAT_PARERR; uart_rx_put(sc, xc); lsr = uart_getreg(bas, REG_LSR); } /* Discard everything left in the Rx FIFO. */ /* * First do a dummy read/discard anyway, in case the UART was lying to us. * This problem was seen on board, when IIR said RBR, but LSR said no RXRDY * Results in a stuck ipend loop. */ (void)uart_getreg(bas, REG_DATA); while (lsr & LSR_RXRDY) { (void)uart_getreg(bas, REG_DATA); uart_barrier(bas); lsr = uart_getreg(bas, REG_LSR); } uart_unlock(sc->sc_hwmtx); return (0); } static int oct16550_bus_setsig (struct uart_softc *sc, int sig) { struct oct16550_softc *oct16550 = (struct oct16550_softc*)sc; struct uart_bas *bas; uint32_t new, old; bas = &sc->sc_bas; do { old = sc->sc_hwsig; new = old; if (sig & SER_DDTR) { SIGCHG(sig & SER_DTR, new, SER_DTR, SER_DDTR); } if (sig & SER_DRTS) { SIGCHG(sig & SER_RTS, new, SER_RTS, SER_DRTS); } } while (!atomic_cmpset_32(&sc->sc_hwsig, old, new)); uart_lock(sc->sc_hwmtx); oct16550->mcr &= ~(MCR_DTR|MCR_RTS); if (new & SER_DTR) oct16550->mcr |= MCR_DTR; if (new & SER_RTS) oct16550->mcr |= MCR_RTS; uart_setreg(bas, REG_MCR, oct16550->mcr); uart_barrier(bas); uart_unlock(sc->sc_hwmtx); return (0); } static int oct16550_bus_transmit (struct uart_softc *sc) { struct oct16550_softc *oct16550 = (struct oct16550_softc*)sc; struct uart_bas *bas; int i; bas = &sc->sc_bas; uart_lock(sc->sc_hwmtx); #ifdef NO_UART_INTERRUPTS for (i = 0; i < sc->sc_txdatasz; i++) { oct16550_putc(bas, sc->sc_txbuf[i]); } #else oct16550_wait_txhr_empty(bas, 100, oct16550_delay(bas)); uart_setreg(bas, REG_IER, oct16550->ier | IER_ETXRDY); uart_barrier(bas); for (i = 0; i < sc->sc_txdatasz; i++) { uart_setreg(bas, REG_DATA, sc->sc_txbuf[i]); uart_barrier(bas); } sc->sc_txbusy = 1; #endif uart_unlock(sc->sc_hwmtx); return (0); } static bool oct16550_bus_txbusy(struct uart_softc *sc) { struct uart_bas *bas = &sc->sc_bas; if ((uart_getreg(bas, REG_LSR) & (LSR_TEMT | LSR_THRE)) != (LSR_TEMT | LSR_THRE)) return (true); return (false); } static void oct16550_bus_grab(struct uart_softc *sc) { struct uart_bas *bas = &sc->sc_bas; /* * turn off all interrupts to enter polling mode. Leave the * saved mask alone. We'll restore whatever it was in ungrab. * All pending interupt signals are reset when IER is set to 0. */ uart_lock(sc->sc_hwmtx); uart_setreg(bas, REG_IER, 0); uart_barrier(bas); uart_unlock(sc->sc_hwmtx); } static void oct16550_bus_ungrab(struct uart_softc *sc) { struct oct16550_softc *oct16550 = (struct oct16550_softc*)sc; struct uart_bas *bas = &sc->sc_bas; /* * Restore previous interrupt mask */ uart_lock(sc->sc_hwmtx); uart_setreg(bas, REG_IER, oct16550->ier); uart_barrier(bas); uart_unlock(sc->sc_hwmtx); }