| Current Path : /sys/dev/uart/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //sys/dev/uart/uart_core.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: release/9.1.0/sys/dev/uart/uart_core.c 225214 2011-08-27 14:24:27Z rwatson $");
#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 <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);
}
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);
}
/*
* 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 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)
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 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;
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(dev, sc->sc_rtype, &sc->sc_rrid,
0, ~0, uart_getrange(sc->sc_class), 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, uart_getrange(sc->sc_class),
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, uart_getrange(sc->sc_class), 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 = 384;
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);
}