/*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * 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. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "uart_if.h" devclass_t uart_devclass; const char uart_driver_name[] = "uart"; SLIST_HEAD(uart_devinfo_list, uart_devinfo) uart_sysdevs = SLIST_HEAD_INITIALIZER(uart_sysdevs); static MALLOC_DEFINE(M_UART, "UART", "UART driver"); #ifndef UART_POLL_FREQ #define UART_POLL_FREQ 50 #endif static int uart_poll_freq = UART_POLL_FREQ; SYSCTL_INT(_debug, OID_AUTO, uart_poll_freq, CTLFLAG_RDTUN, &uart_poll_freq, 0, "UART poll frequency"); static int uart_force_poll; SYSCTL_INT(_debug, OID_AUTO, uart_force_poll, CTLFLAG_RDTUN, &uart_force_poll, 0, "Force UART polling"); static inline int uart_pps_mode_valid(int pps_mode) { int opt; switch(pps_mode & UART_PPS_SIGNAL_MASK) { case UART_PPS_DISABLED: case UART_PPS_CTS: case UART_PPS_DCD: break; default: return (false); } opt = pps_mode & UART_PPS_OPTION_MASK; if ((opt & ~(UART_PPS_INVERT_PULSE | UART_PPS_NARROW_PULSE)) != 0) return (false); return (true); } static void uart_pps_print_mode(struct uart_softc *sc) { device_printf(sc->sc_dev, "PPS capture mode: "); switch(sc->sc_pps_mode & UART_PPS_SIGNAL_MASK) { case UART_PPS_DISABLED: printf("disabled"); break; case UART_PPS_CTS: printf("CTS"); break; case UART_PPS_DCD: printf("DCD"); break; default: printf("invalid"); break; } if (sc->sc_pps_mode & UART_PPS_INVERT_PULSE) printf("-Inverted"); if (sc->sc_pps_mode & UART_PPS_NARROW_PULSE) printf("-NarrowPulse"); printf("\n"); } static int uart_pps_mode_sysctl(SYSCTL_HANDLER_ARGS) { struct uart_softc *sc; int err, tmp; sc = arg1; tmp = sc->sc_pps_mode; err = sysctl_handle_int(oidp, &tmp, 0, req); if (err != 0 || req->newptr == NULL) return (err); if (!uart_pps_mode_valid(tmp)) return (EINVAL); sc->sc_pps_mode = tmp; return(0); } static void uart_pps_process(struct uart_softc *sc, int ser_sig) { sbintime_t now; int is_assert, pps_sig; /* Which signal is configured as PPS? Early out if none. */ switch(sc->sc_pps_mode & UART_PPS_SIGNAL_MASK) { case UART_PPS_CTS: pps_sig = SER_CTS; break; case UART_PPS_DCD: pps_sig = SER_DCD; break; default: return; } /* Early out if there is no change in the signal configured as PPS. */ if ((ser_sig & SER_DELTA(pps_sig)) == 0) return; /* * In narrow-pulse mode we need to synthesize both capture and clear * events from a single "delta occurred" indication from the uart * hardware because the pulse width is too narrow to reliably detect * both edges. However, when the pulse width is close to our interrupt * processing latency we might intermittantly catch both edges. To * guard against generating spurious events when that happens, we use a * separate timer to ensure at least half a second elapses before we * generate another event. */ pps_capture(&sc->sc_pps); if (sc->sc_pps_mode & UART_PPS_NARROW_PULSE) { now = getsbinuptime(); if (now > sc->sc_pps_captime + 500 * SBT_1MS) { sc->sc_pps_captime = now; pps_event(&sc->sc_pps, PPS_CAPTUREASSERT); pps_event(&sc->sc_pps, PPS_CAPTURECLEAR); } } else { is_assert = ser_sig & pps_sig; if (sc->sc_pps_mode & UART_PPS_INVERT_PULSE) is_assert = !is_assert; pps_event(&sc->sc_pps, is_assert ? PPS_CAPTUREASSERT : PPS_CAPTURECLEAR); } } static void uart_pps_init(struct uart_softc *sc) { struct sysctl_ctx_list *ctx; struct sysctl_oid *tree; ctx = device_get_sysctl_ctx(sc->sc_dev); tree = device_get_sysctl_tree(sc->sc_dev); /* * The historical default for pps capture mode is either DCD or CTS, * depending on the UART_PPS_ON_CTS kernel option. Start with that, * then try to fetch the tunable that overrides the mode for all uart * devices, then try to fetch the sysctl-tunable that overrides the mode * for one specific device. */ #ifdef UART_PPS_ON_CTS sc->sc_pps_mode = UART_PPS_CTS; #else sc->sc_pps_mode = UART_PPS_DCD; #endif TUNABLE_INT_FETCH("hw.uart.pps_mode", &sc->sc_pps_mode); SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, "pps_mode", CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_MPSAFE, sc, 0, uart_pps_mode_sysctl, "I", "pulse mode: 0/1/2=disabled/CTS/DCD; " "add 0x10 to invert, 0x20 for narrow pulse"); if (!uart_pps_mode_valid(sc->sc_pps_mode)) { device_printf(sc->sc_dev, "Invalid pps_mode 0x%02x configured; disabling PPS capture\n", sc->sc_pps_mode); sc->sc_pps_mode = UART_PPS_DISABLED; } else if (bootverbose) { uart_pps_print_mode(sc); } sc->sc_pps.ppscap = PPS_CAPTUREBOTH; sc->sc_pps.driver_mtx = uart_tty_getlock(sc); sc->sc_pps.driver_abi = PPS_ABI_VERSION; pps_init_abi(&sc->sc_pps); } void uart_add_sysdev(struct uart_devinfo *di) { SLIST_INSERT_HEAD(&uart_sysdevs, di, next); } const char * uart_getname(struct uart_class *uc) { return ((uc != NULL) ? uc->name : NULL); } struct uart_ops * uart_getops(struct uart_class *uc) { return ((uc != NULL) ? uc->uc_ops : NULL); } int uart_getrange(struct uart_class *uc) { return ((uc != NULL) ? uc->uc_range : 0); } u_int uart_getregshift(struct uart_class *uc) { return ((uc != NULL) ? uc->uc_rshift : 0); } u_int uart_getregiowidth(struct uart_class *uc) { return ((uc != NULL) ? uc->uc_riowidth : 0); } /* * Schedule a soft interrupt. We do this on the 0 to !0 transition * of the TTY pending interrupt status. */ void uart_sched_softih(struct uart_softc *sc, uint32_t ipend) { uint32_t new, old; do { old = sc->sc_ttypend; new = old | ipend; } while (!atomic_cmpset_32(&sc->sc_ttypend, old, new)); if ((old & SER_INT_MASK) == 0) swi_sched(sc->sc_softih, 0); } /* * A break condition has been detected. We treat the break condition as * a special case that should not happen during normal operation. When * the break condition is to be passed to higher levels in the form of * a NUL character, we really want the break to be in the right place in * the input stream. The overhead to achieve that is not in relation to * the exceptional nature of the break condition, so we permit ourselves * to be sloppy. */ static __inline int uart_intr_break(void *arg) { struct uart_softc *sc = arg; #if defined(KDB) if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE) { if (kdb_break()) return (0); } #endif if (sc->sc_opened) uart_sched_softih(sc, SER_INT_BREAK); return (0); } /* * Handle a receiver overrun situation. We lost at least 1 byte in the * input stream and it's our job to contain the situation. We grab as * much of the data we can, but otherwise flush the receiver FIFO to * create some breathing room. The net effect is that we avoid the * overrun condition to happen for the next X characters, where X is * related to the FIFO size at the cost of losing data right away. * So, instead of having multiple overrun interrupts in close proximity * to each other and possibly pessimizing UART interrupt latency for * other UARTs in a multiport configuration, we create a longer segment * of missing characters by freeing up the FIFO. * Each overrun condition is marked in the input buffer by a token. The * token represents the loss of at least one, but possible more bytes in * the input stream. */ static __inline int uart_intr_overrun(void *arg) { struct uart_softc *sc = arg; if (sc->sc_opened) { UART_RECEIVE(sc); if (uart_rx_put(sc, UART_STAT_OVERRUN)) sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN; uart_sched_softih(sc, SER_INT_RXREADY); } sc->sc_rxoverruns++; UART_FLUSH(sc, UART_FLUSH_RECEIVER); return (0); } /* * Received data ready. */ static __inline int uart_intr_rxready(void *arg) { struct uart_softc *sc = arg; int rxp; rxp = sc->sc_rxput; UART_RECEIVE(sc); #if defined(KDB) if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE) { while (rxp != sc->sc_rxput) { kdb_alt_break(sc->sc_rxbuf[rxp++], &sc->sc_altbrk); if (rxp == sc->sc_rxbufsz) rxp = 0; } } #endif if (sc->sc_opened) uart_sched_softih(sc, SER_INT_RXREADY); else sc->sc_rxput = sc->sc_rxget; /* Ignore received data. */ return (1); } /* * Line or modem status change (OOB signalling). * We pass the signals to the software interrupt handler for further * processing. Note that we merge the delta bits, but set the state * bits. This is to avoid losing state transitions due to having more * than 1 hardware interrupt between software interrupts. */ static __inline int uart_intr_sigchg(void *arg) { struct uart_softc *sc = arg; int new, old, sig; sig = UART_GETSIG(sc); /* * Time pulse counting support, invoked whenever the PPS parameters are * currently set to capture either edge of the signal. */ if (sc->sc_pps.ppsparam.mode & PPS_CAPTUREBOTH) { uart_pps_process(sc, sig); } /* * Keep track of signal changes, even when the device is not * opened. This allows us to inform upper layers about a * possible loss of DCD and thus the existence of a (possibly) * different connection when we have DCD back, during the time * that the device was closed. */ do { old = sc->sc_ttypend; new = old & ~SER_MASK_STATE; new |= sig & SER_INT_SIGMASK; } while (!atomic_cmpset_32(&sc->sc_ttypend, old, new)); if (sc->sc_opened) uart_sched_softih(sc, SER_INT_SIGCHG); return (1); } /* * The transmitter can accept more data. */ static __inline int uart_intr_txidle(void *arg) { struct uart_softc *sc = arg; if (sc->sc_txbusy) { sc->sc_txbusy = 0; uart_sched_softih(sc, SER_INT_TXIDLE); } return (0); } static int uart_intr(void *arg) { struct uart_softc *sc = arg; int cnt, ipend, testintr; if (sc->sc_leaving) return (FILTER_STRAY); cnt = 0; testintr = sc->sc_testintr; while ((!testintr || cnt < 20) && (ipend = UART_IPEND(sc)) != 0) { cnt++; if (ipend & SER_INT_OVERRUN) uart_intr_overrun(sc); if (ipend & SER_INT_BREAK) uart_intr_break(sc); if (ipend & SER_INT_RXREADY) uart_intr_rxready(sc); if (ipend & SER_INT_SIGCHG) uart_intr_sigchg(sc); if (ipend & SER_INT_TXIDLE) uart_intr_txidle(sc); } if (sc->sc_polled) { callout_reset(&sc->sc_timer, hz / uart_poll_freq, (callout_func_t *)uart_intr, sc); } return ((cnt == 0) ? FILTER_STRAY : ((testintr && cnt == 20) ? FILTER_SCHEDULE_THREAD : FILTER_HANDLED)); } serdev_intr_t * uart_bus_ihand(device_t dev, int ipend) { switch (ipend) { case SER_INT_BREAK: return (uart_intr_break); case SER_INT_OVERRUN: return (uart_intr_overrun); case SER_INT_RXREADY: return (uart_intr_rxready); case SER_INT_SIGCHG: return (uart_intr_sigchg); case SER_INT_TXIDLE: return (uart_intr_txidle); } return (NULL); } int uart_bus_ipend(device_t dev) { struct uart_softc *sc; sc = device_get_softc(dev); return (UART_IPEND(sc)); } int uart_bus_sysdev(device_t dev) { struct uart_softc *sc; sc = device_get_softc(dev); return ((sc->sc_sysdev != NULL) ? 1 : 0); } int uart_bus_probe(device_t dev, int regshft, int regiowidth, int rclk, int rid, int chan, int quirks) { struct uart_softc *sc; struct uart_devinfo *sysdev; int error; sc = device_get_softc(dev); /* * All uart_class references are weak. Check that the needed * class has been compiled-in. Fail if not. */ if (sc->sc_class == NULL) return (ENXIO); /* * Initialize the instance. Note that the instance (=softc) does * not necessarily match the hardware specific softc. We can't do * anything about it now, because we may not attach to the device. * Hardware drivers cannot use any of the class specific fields * while probing. */ kobj_init((kobj_t)sc, (kobj_class_t)sc->sc_class); sc->sc_dev = dev; if (device_get_desc(dev) == NULL) device_set_desc(dev, uart_getname(sc->sc_class)); /* * Allocate the register resource. We assume that all UARTs have * a single register window in either I/O port space or memory * mapped I/O space. Any UART that needs multiple windows will * consequently not be supported by this driver as-is. We try I/O * port space first because that's the common case. */ sc->sc_rrid = rid; sc->sc_rtype = SYS_RES_IOPORT; sc->sc_rres = bus_alloc_resource_any(dev, sc->sc_rtype, &sc->sc_rrid, RF_ACTIVE); if (sc->sc_rres == NULL) { sc->sc_rrid = rid; sc->sc_rtype = SYS_RES_MEMORY; sc->sc_rres = bus_alloc_resource_any(dev, sc->sc_rtype, &sc->sc_rrid, RF_ACTIVE); if (sc->sc_rres == NULL) return (ENXIO); } /* * Fill in the bus access structure and compare this device with * a possible console device and/or a debug port. We set the flags * in the softc so that the hardware dependent probe can adjust * accordingly. In general, you don't want to permanently disrupt * console I/O. */ sc->sc_bas.bsh = rman_get_bushandle(sc->sc_rres); sc->sc_bas.bst = rman_get_bustag(sc->sc_rres); sc->sc_bas.chan = chan; sc->sc_bas.regshft = regshft; sc->sc_bas.regiowidth = regiowidth; sc->sc_bas.rclk = (rclk == 0) ? sc->sc_class->uc_rclk : rclk; sc->sc_bas.busy_detect = !!(quirks & UART_F_BUSY_DETECT); SLIST_FOREACH(sysdev, &uart_sysdevs, next) { if (chan == sysdev->bas.chan && uart_cpu_eqres(&sc->sc_bas, &sysdev->bas)) { /* XXX check if ops matches class. */ sc->sc_sysdev = sysdev; sysdev->bas.rclk = sc->sc_bas.rclk; } } error = UART_PROBE(sc); bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres); return ((error) ? error : BUS_PROBE_DEFAULT); } int uart_bus_attach(device_t dev) { struct uart_softc *sc, *sc0; const char *sep; int error, filt; /* * The sc_class field defines the type of UART we're going to work * with and thus the size of the softc. Replace the generic softc * with one that matches the UART now that we're certain we handle * the device. */ sc0 = device_get_softc(dev); if (sc0->sc_class->size > device_get_driver(dev)->size) { sc = malloc(sc0->sc_class->size, M_UART, M_WAITOK|M_ZERO); bcopy(sc0, sc, sizeof(*sc)); device_set_softc(dev, sc); } else sc = sc0; /* * Now that we know the softc for this device, connect the back * pointer from the sysdev for this device, if any */ if (sc->sc_sysdev != NULL) sc->sc_sysdev->sc = sc; /* * Protect ourselves against interrupts while we're not completely * finished attaching and initializing. We don't expect interrupts * until after UART_ATTACH(), though. */ sc->sc_leaving = 1; mtx_init(&sc->sc_hwmtx_s, "uart_hwmtx", NULL, MTX_SPIN); if (sc->sc_hwmtx == NULL) sc->sc_hwmtx = &sc->sc_hwmtx_s; /* * Re-allocate. We expect that the softc contains the information * collected by uart_bus_probe() intact. */ sc->sc_rres = bus_alloc_resource_any(dev, sc->sc_rtype, &sc->sc_rrid, RF_ACTIVE); if (sc->sc_rres == NULL) { mtx_destroy(&sc->sc_hwmtx_s); return (ENXIO); } sc->sc_bas.bsh = rman_get_bushandle(sc->sc_rres); sc->sc_bas.bst = rman_get_bustag(sc->sc_rres); /* * Ensure there is room for at least three full FIFOs of data in the * receive buffer (handles the case of low-level drivers with huge * FIFOs), and also ensure that there is no less than the historical * size of 384 bytes (handles the typical small-FIFO case). */ sc->sc_rxbufsz = MAX(384, sc->sc_rxfifosz * 3); sc->sc_rxbuf = malloc(sc->sc_rxbufsz * sizeof(*sc->sc_rxbuf), M_UART, M_WAITOK); sc->sc_txbuf = malloc(sc->sc_txfifosz * sizeof(*sc->sc_txbuf), M_UART, M_WAITOK); error = UART_ATTACH(sc); if (error) goto fail; if (sc->sc_hwiflow || sc->sc_hwoflow) { sep = ""; device_print_prettyname(dev); if (sc->sc_hwiflow) { printf("%sRTS iflow", sep); sep = ", "; } if (sc->sc_hwoflow) { printf("%sCTS oflow", sep); sep = ", "; } printf("\n"); } if (sc->sc_sysdev != NULL) { if (sc->sc_sysdev->baudrate == 0) { if (UART_IOCTL(sc, UART_IOCTL_BAUD, (intptr_t)&sc->sc_sysdev->baudrate) != 0) sc->sc_sysdev->baudrate = -1; } switch (sc->sc_sysdev->type) { case UART_DEV_CONSOLE: device_printf(dev, "console"); break; case UART_DEV_DBGPORT: device_printf(dev, "debug port"); break; case UART_DEV_KEYBOARD: device_printf(dev, "keyboard"); break; default: device_printf(dev, "unknown system device"); break; } printf(" (%d,%c,%d,%d)\n", sc->sc_sysdev->baudrate, "noems"[sc->sc_sysdev->parity], sc->sc_sysdev->databits, sc->sc_sysdev->stopbits); } sc->sc_leaving = 0; sc->sc_testintr = 1; filt = uart_intr(sc); sc->sc_testintr = 0; /* * Don't use interrupts if we couldn't clear any pending interrupt * conditions. We may have broken H/W and polling is probably the * safest thing to do. */ if (filt != FILTER_SCHEDULE_THREAD && !uart_force_poll) { sc->sc_ires = bus_alloc_resource_any(dev, SYS_RES_IRQ, &sc->sc_irid, RF_ACTIVE | RF_SHAREABLE); } if (sc->sc_ires != NULL) { error = bus_setup_intr(dev, sc->sc_ires, INTR_TYPE_TTY, uart_intr, NULL, sc, &sc->sc_icookie); sc->sc_fastintr = (error == 0) ? 1 : 0; if (!sc->sc_fastintr) error = bus_setup_intr(dev, sc->sc_ires, INTR_TYPE_TTY | INTR_MPSAFE, NULL, (driver_intr_t *)uart_intr, sc, &sc->sc_icookie); if (error) { device_printf(dev, "could not activate interrupt\n"); bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irid, sc->sc_ires); sc->sc_ires = NULL; } } if (sc->sc_ires == NULL) { /* No interrupt resource. Force polled mode. */ sc->sc_polled = 1; callout_init(&sc->sc_timer, 1); callout_reset(&sc->sc_timer, hz / uart_poll_freq, (callout_func_t *)uart_intr, sc); } if (bootverbose && (sc->sc_fastintr || sc->sc_polled)) { sep = ""; device_print_prettyname(dev); if (sc->sc_fastintr) { printf("%sfast interrupt", sep); sep = ", "; } if (sc->sc_polled) { printf("%spolled mode (%dHz)", sep, uart_poll_freq); sep = ", "; } printf("\n"); } if (sc->sc_sysdev != NULL && sc->sc_sysdev->attach != NULL) { if ((error = sc->sc_sysdev->attach(sc)) != 0) goto fail; } else { if ((error = uart_tty_attach(sc)) != 0) goto fail; uart_pps_init(sc); } if (sc->sc_sysdev != NULL) sc->sc_sysdev->hwmtx = sc->sc_hwmtx; if (sc->sc_rxfifosz > 1) SYSCTL_ADD_INT(device_get_sysctl_ctx(dev), SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), OID_AUTO, "rx_overruns", CTLFLAG_RD, &sc->sc_rxoverruns, 0, "Receive overruns"); return (0); fail: free(sc->sc_txbuf, M_UART); free(sc->sc_rxbuf, M_UART); if (sc->sc_ires != NULL) { bus_teardown_intr(dev, sc->sc_ires, sc->sc_icookie); bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irid, sc->sc_ires); } bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres); mtx_destroy(&sc->sc_hwmtx_s); return (error); } int uart_bus_detach(device_t dev) { struct uart_softc *sc; sc = device_get_softc(dev); sc->sc_leaving = 1; if (sc->sc_sysdev != NULL) sc->sc_sysdev->hwmtx = NULL; UART_DETACH(sc); if (sc->sc_sysdev != NULL && sc->sc_sysdev->detach != NULL) (*sc->sc_sysdev->detach)(sc); else uart_tty_detach(sc); free(sc->sc_txbuf, M_UART); free(sc->sc_rxbuf, M_UART); if (sc->sc_ires != NULL) { bus_teardown_intr(dev, sc->sc_ires, sc->sc_icookie); bus_release_resource(dev, SYS_RES_IRQ, sc->sc_irid, sc->sc_ires); } bus_release_resource(dev, sc->sc_rtype, sc->sc_rrid, sc->sc_rres); mtx_destroy(&sc->sc_hwmtx_s); if (sc->sc_class->size > device_get_driver(dev)->size) { device_set_softc(dev, NULL); free(sc, M_UART); } return (0); } int uart_bus_resume(device_t dev) { struct uart_softc *sc; sc = device_get_softc(dev); return (UART_ATTACH(sc)); } void uart_grab(struct uart_devinfo *di) { if (di->sc) UART_GRAB(di->sc); } void uart_ungrab(struct uart_devinfo *di) { if (di->sc) UART_UNGRAB(di->sc); }