Introduce the hw.uart.console and hw.uart.dbgport environment variables

to select a serial console and debug port (resp). On ia64 these replace
the use of hints completely and take precedence over hints on alpha,
amd64 and i386. On sparc64 these variables are not yet recognised.

The reasons for introducing these variables are:
1.  Hints have side-effects. They reserve the unit number for use by
    isa or acpi devices and therefore cannot be used to select a pci
    device. Also, the use of a unit number to select a device prior
    to bus enumeration is nonsense. The new variables have no side-
    effects and are not based on unit numbers.
2.  Hints don't have the expression power to allow the sysadmin to
    select UARTs that are not legacy PC devices and need the support
    of compile-time constants to give the sysadmin some level of
    flexibility.

The hw.uart.console and hw.uart.dbgport variables specify a list of
attributes. An attribute is a tag-value pair, seperated by a colon.
Attributes are seperated by a comma. Where possible, tags are the
same as those in /etc/remote (only br and pa in practice). Details
can be found in the manpage (not part of this commit).

Not tested on: amd64, pc98

1 files changed, 247 insertions, 0 deletions

diff --git a/sys/dev/uart/uart_subr.c b/sys/dev/uart/uart_subr.c
new file mode 100644
index 0000000..9a3cb85
--- /dev/null
+++ b/sys/dev/uart/uart_subr.c
@@ -0,0 +1,247 @@
+/*
+ * 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 bus_addr_t
+uart_parse_addr(__const char **p)
+{
+	return (strtoul(*p, (char**)(uintptr_t)p, 0));
+}
+
+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)
+{
+	__const char *spec;
+	bus_addr_t addr = ~0U;
+
+	/*
+	 * 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
+		return (ENXIO);
+
+	/* Set defaults. */
+	di->ops = uart_ns8250_ops;
+	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:
+			return (EINVAL);	/* XXX not yet implemented. */
+			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);
+	/* XXX the size of the mapping depends on the UART class. */
+	if (bus_space_map(di->bas.bst, addr, 8, 0, &di->bas.bsh) != 0)
+		return (EINVAL);
+	return (0);
+}