freebsd-nq/sys/dev/uart/uart_core.c
Marcel Moolenaar 1c5e367bcc When we match UARTs found during bus-enumeration with UARTs used for
system devices (i.e. console, debug port or keyboard), don't stop
after the first match. Find them all and keep track of the last.
The reason for this change is that the low-level console is always
added to the list of system devices first, with other devices added
later. Since new devices are added to the list at the head, we have
the console always at the end. When a debug port is using the same
UART as the console, we would previously mark the "newbus" UART as
a debug port instead of as a console. This would later result in a
panic because no "newbus" device was associated with the console.
By matching all possible system devices we would mark the "newbus"
UART as a console and not as a debug port.
While it is arguably better to be able to mark a "newbus" UART as
both console and debug port, this fix is lightweight and allows
a single UART to be used as the console as well as a debug port
with only the aesthetic bug of not telling the user about it also
being a debug port.

Now that we match all possible system devices, update the rclk of
the system devices with the rclk that was obtained through the
bus attachment. It is generally true that clock information is
more reliable when obtained from the parent bus than by means of
some hardcoded or assumed value used early in the boot. This by
virtue of having more context information.

MFC after: 1 month
2007-03-28 18:26:12 +00:00

560 lines
15 KiB
C

/*-
* 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#ifndef KLD_MODULE
#include "opt_comconsole.h"
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/fcntl.h>
#include <sys/interrupt.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/queue.h>
#include <sys/reboot.h>
#include <machine/bus.h>
#include <sys/rman.h>
#include <sys/termios.h>
#include <sys/tty.h>
#include <machine/resource.h>
#include <machine/stdarg.h>
#include <dev/uart/uart.h>
#include <dev/uart/uart_bus.h>
#include <dev/uart/uart_cpu.h>
#include "uart_if.h"
devclass_t uart_devclass;
char uart_driver_name[] = "uart";
SLIST_HEAD(uart_devinfo_list, uart_devinfo) uart_sysdevs =
SLIST_HEAD_INITIALIZER(uart_sysdevs);
MALLOC_DEFINE(M_UART, "UART", "UART driver");
void
uart_add_sysdev(struct uart_devinfo *di)
{
SLIST_INSERT_HEAD(&uart_sysdevs, di, next);
}
/*
* Schedule a soft interrupt. We do this on the 0 to !0 transition
* of the TTY pending interrupt status.
*/
static 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) && defined(BREAK_TO_DEBUGGER)
if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE) {
kdb_enter("Line break on console");
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 loosing 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);
}
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) && defined(ALT_BREAK_TO_DEBUGGER)
if (sc->sc_sysdev != NULL && sc->sc_sysdev->type == UART_DEV_CONSOLE) {
while (rxp != sc->sc_rxput) {
if (kdb_alt_break(sc->sc_rxbuf[rxp++], &sc->sc_altbrk))
kdb_enter("Break sequence on console");
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 loosing 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);
if (sc->sc_pps.ppsparam.mode & PPS_CAPTUREBOTH) {
if (sig & UART_SIG_DPPS) {
pps_capture(&sc->sc_pps);
pps_event(&sc->sc_pps, (sig & UART_SIG_PPS) ?
PPS_CAPTUREASSERT : PPS_CAPTURECLEAR);
}
}
/*
* 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 flag = 0, ipend;
while (!sc->sc_leaving && (ipend = UART_IPEND(sc)) != 0) {
flag = 1;
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);
}
return((flag)?FILTER_HANDLED:FILTER_STRAY);
}
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 rclk, int rid, int chan)
{
struct uart_softc *sc;
struct uart_devinfo *sysdev;
int error;
/*
* 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.
*/
sc = device_get_softc(dev);
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, sc->sc_class->name);
/*
* 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(dev, sc->sc_rtype, &sc->sc_rrid,
0, ~0, sc->sc_class->uc_range, RF_ACTIVE);
if (sc->sc_rres == NULL) {
sc->sc_rrid = rid;
sc->sc_rtype = SYS_RES_MEMORY;
sc->sc_rres = bus_alloc_resource(dev, sc->sc_rtype,
&sc->sc_rrid, 0, ~0, sc->sc_class->uc_range, 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.rclk = (rclk == 0) ? sc->sc_class->uc_rclk : rclk;
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;
/*
* 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 > sizeof(*sc)) {
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;
/*
* 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(dev, sc->sc_rtype, &sc->sc_rrid,
0, ~0, sc->sc_class->uc_range, 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);
sc->sc_irid = 0;
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);
if (error)
error = bus_setup_intr(dev,
sc->sc_ires, INTR_TYPE_TTY | INTR_MPSAFE,
NULL, (driver_intr_t *)uart_intr, sc, &sc->sc_icookie);
else
sc->sc_fastintr = 1;
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) {
/* XXX no interrupt resource. Force polled mode. */
sc->sc_polled = 1;
}
sc->sc_rxbufsz = IBUFSIZ;
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 (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", 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_pps.ppscap = PPS_CAPTUREBOTH;
pps_init(&sc->sc_pps);
error = (sc->sc_sysdev != NULL && sc->sc_sysdev->attach != NULL)
? (*sc->sc_sysdev->attach)(sc) : uart_tty_attach(sc);
if (error)
goto fail;
if (sc->sc_sysdev != NULL)
sc->sc_sysdev->hwmtx = sc->sc_hwmtx;
sc->sc_leaving = 0;
uart_intr(sc);
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 > sizeof(*sc)) {
device_set_softc(dev, NULL);
free(sc, M_UART);
} else
device_set_softc(dev, NULL);
return (0);
}