freebsd-skq/sys/dev/uart/uart_subr.c
Marcel Moolenaar f8100ce2a7 Don't expose the uart_ops structure directly, but instead have
it obtained through the uart_class structure. This allows us
to declare the uart_class structure as weak and as such allows
us to reference it even when it's not compiled-in.
It also allows is to get the uart_ops structure by name, which
makes it possible to implement the dt tag handling in uart_getenv().
The side-effect of all this is that we're using the uart_class
structure more consistently which means that we now also have
access to the size of the bus space block needed by the hardware
when we map the bus space, eliminating any hardcoding.
2007-04-02 22:00:22 +00:00

307 lines
7.0 KiB
C

/*-
* Copyright (c) 2004 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("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <machine/bus.h>
#include <machine/vmparam.h>
#include <dev/uart/uart.h>
#include <dev/uart/uart_cpu.h>
#define UART_TAG_BR 0
#define UART_TAG_CH 1
#define UART_TAG_DB 2
#define UART_TAG_DT 3
#define UART_TAG_IO 4
#define UART_TAG_MM 5
#define UART_TAG_PA 6
#define UART_TAG_RS 7
#define UART_TAG_SB 8
#define UART_TAG_XO 9
static struct uart_class *uart_classes[] = {
&uart_ns8250_class,
&uart_sab82532_class,
&uart_z8530_class,
};
static size_t uart_nclasses = sizeof(uart_classes) / sizeof(uart_classes[0]);
static bus_addr_t
uart_parse_addr(__const char **p)
{
return (strtoul(*p, (char**)(uintptr_t)p, 0));
}
static struct uart_class *
uart_parse_class(struct uart_class *class, __const char **p)
{
struct uart_class *uc;
const char *nm;
size_t len;
u_int i;
for (i = 0; i < uart_nclasses; i++) {
uc = uart_classes[i];
nm = uart_getname(uc);
if (nm == NULL || *nm == '\0')
continue;
len = strlen(nm);
if (strncmp(nm, *p, len) == 0) {
*p += len;
return (uc);
}
}
return (class);
}
static long
uart_parse_long(__const char **p)
{
return (strtol(*p, (char**)(uintptr_t)p, 0));
}
static int
uart_parse_parity(__const char **p)
{
if (!strncmp(*p, "even", 4)) {
*p += 4;
return UART_PARITY_EVEN;
}
if (!strncmp(*p, "mark", 4)) {
*p += 4;
return UART_PARITY_MARK;
}
if (!strncmp(*p, "none", 4)) {
*p += 4;
return UART_PARITY_NONE;
}
if (!strncmp(*p, "odd", 3)) {
*p += 3;
return UART_PARITY_ODD;
}
if (!strncmp(*p, "space", 5)) {
*p += 5;
return UART_PARITY_SPACE;
}
return (-1);
}
static int
uart_parse_tag(__const char **p)
{
int tag;
if ((*p)[0] == 'b' && (*p)[1] == 'r') {
tag = UART_TAG_BR;
goto out;
}
if ((*p)[0] == 'c' && (*p)[1] == 'h') {
tag = UART_TAG_CH;
goto out;
}
if ((*p)[0] == 'd' && (*p)[1] == 'b') {
tag = UART_TAG_DB;
goto out;
}
if ((*p)[0] == 'd' && (*p)[1] == 't') {
tag = UART_TAG_DT;
goto out;
}
if ((*p)[0] == 'i' && (*p)[1] == 'o') {
tag = UART_TAG_IO;
goto out;
}
if ((*p)[0] == 'm' && (*p)[1] == 'm') {
tag = UART_TAG_MM;
goto out;
}
if ((*p)[0] == 'p' && (*p)[1] == 'a') {
tag = UART_TAG_PA;
goto out;
}
if ((*p)[0] == 'r' && (*p)[1] == 's') {
tag = UART_TAG_RS;
goto out;
}
if ((*p)[0] == 's' && (*p)[1] == 'b') {
tag = UART_TAG_SB;
goto out;
}
if ((*p)[0] == 'x' && (*p)[1] == 'o') {
tag = UART_TAG_XO;
goto out;
}
return (-1);
out:
*p += 2;
if ((*p)[0] != ':')
return (-1);
(*p)++;
return (tag);
}
/*
* Parse a device specification. The specification is a list of attributes
* seperated by commas. Each attribute is a tag-value pair with the tag and
* value seperated by a colon. Supported tags are:
*
* br = Baudrate
* ch = Channel
* db = Data bits
* dt = Device type
* io = I/O port address
* mm = Memory mapped I/O address
* pa = Parity
* rs = Register shift
* sb = Stopbits
* xo = Device clock (xtal oscillator)
*
* The io and mm tags are mutually exclusive.
*/
int
uart_getenv(int devtype, struct uart_devinfo *di, struct uart_class *class)
{
__const char *spec;
bus_addr_t addr = ~0U;
int error;
/*
* All uart_class references are weak. Make sure the default
* device class has been compiled-in.
*/
if (class == NULL)
return (ENXIO);
/*
* Check the environment variables "hw.uart.console" and
* "hw.uart.dbgport". These variables, when present, specify
* which UART port is to be used as serial console or debug
* port (resp).
*/
if (devtype == UART_DEV_CONSOLE)
spec = getenv("hw.uart.console");
else if (devtype == UART_DEV_DBGPORT)
spec = getenv("hw.uart.dbgport");
else
spec = NULL;
if (spec == NULL)
return (ENXIO);
/* Set defaults. */
di->bas.chan = 0;
di->bas.regshft = 0;
di->bas.rclk = 0;
di->baudrate = 0;
di->databits = 8;
di->stopbits = 1;
di->parity = UART_PARITY_NONE;
/* Parse the attributes. */
while (1) {
switch (uart_parse_tag(&spec)) {
case UART_TAG_BR:
di->baudrate = uart_parse_long(&spec);
break;
case UART_TAG_CH:
di->bas.chan = uart_parse_long(&spec);
break;
case UART_TAG_DB:
di->databits = uart_parse_long(&spec);
break;
case UART_TAG_DT:
class = uart_parse_class(class, &spec);
break;
case UART_TAG_IO:
di->bas.bst = uart_bus_space_io;
addr = uart_parse_addr(&spec);
break;
case UART_TAG_MM:
di->bas.bst = uart_bus_space_mem;
addr = uart_parse_addr(&spec);
break;
case UART_TAG_PA:
di->parity = uart_parse_parity(&spec);
break;
case UART_TAG_RS:
di->bas.regshft = uart_parse_long(&spec);
break;
case UART_TAG_SB:
di->stopbits = uart_parse_long(&spec);
break;
case UART_TAG_XO:
di->bas.rclk = uart_parse_long(&spec);
break;
default:
return (EINVAL);
}
if (*spec == '\0')
break;
if (*spec != ',')
return (EINVAL);
spec++;
}
/*
* If we still have an invalid address, the specification must be
* missing an I/O port or memory address. We don't like that.
*/
if (addr == ~0U)
return (EINVAL);
/*
* Accept only the well-known baudrates. Any invalid baudrate
* is silently replaced with a 0-valued baudrate. The 0 baudrate
* has special meaning. It means that we're not supposed to
* program the baudrate and simply communicate with whatever
* speed the hardware is currently programmed for.
*/
if (di->baudrate >= 19200) {
if (di->baudrate % 19200)
di->baudrate = 0;
} else if (di->baudrate >= 1200) {
if (di->baudrate % 1200)
di->baudrate = 0;
} else if (di->baudrate > 0) {
if (di->baudrate % 75)
di->baudrate = 0;
} else
di->baudrate = 0;
/* Set the ops and create a bus space handle. */
di->ops = uart_getops(class);
error = bus_space_map(di->bas.bst, addr, uart_getrange(class), 0,
&di->bas.bsh);
return (error);
}