FDT (simplebus) compatible attachment for uart(4).

This will be a single uart(4) attachment code shared by all FDT-enabled
platforms.

Reviewed by:	imp
Sponsored by:	The FreeBSD Foundation

1 files changed, 200 insertions, 0 deletions

diff --git a/sys/dev/uart/uart_bus_fdt.c b/sys/dev/uart/uart_bus_fdt.c
new file mode 100644
index 0000000..b958c10
--- /dev/null
+++ b/sys/dev/uart/uart_bus_fdt.c
@@ -0,0 +1,200 @@
+/*-
+ * Copyright (c) 2009-2010 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Semihalf under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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/bus.h>
+#include <sys/kernel.h>
+#include <sys/module.h>
+
+#include <machine/bus.h>
+#include <machine/fdt.h>
+
+#include <dev/fdt/fdt_common.h>
+#include <dev/ofw/ofw_bus.h>
+#include <dev/ofw/ofw_bus_subr.h>
+#include <dev/uart/uart.h>
+#include <dev/uart/uart_bus.h>
+#include <dev/uart/uart_cpu.h>
+
+static int uart_fdt_probe(device_t);
+
+static device_method_t uart_fdt_methods[] = {
+	/* Device interface */
+	DEVMETHOD(device_probe,		uart_fdt_probe),
+	DEVMETHOD(device_attach,	uart_bus_attach),
+	DEVMETHOD(device_detach,	uart_bus_detach),
+	{ 0, 0 }
+};
+
+static driver_t uart_fdt_driver = {
+	uart_driver_name,
+	uart_fdt_methods,
+	sizeof(struct uart_softc),
+};
+
+static int
+uart_fdt_get_clock(phandle_t node, pcell_t *cell)
+{
+	pcell_t clock;
+
+	if ((OF_getprop(node, "clock-frequency", &clock,
+	    sizeof(clock))) <= 0)
+		return (ENXIO);
+
+	if (clock == 0)
+		/* Try to retrieve parent 'bus-frequency' */
+		/* XXX this should go to simple-bus fixup or so */
+		if ((OF_getprop(OF_parent(node), "bus-frequency", &clock,
+		    sizeof(clock))) <= 0)
+			clock = 0;
+
+	*cell = fdt32_to_cpu(clock);
+	return (0);
+}
+
+static int
+uart_fdt_get_shift(phandle_t node, pcell_t *cell)
+{
+	pcell_t shift;
+
+	if ((OF_getprop(node, "reg-shift", &shift, sizeof(shift))) <= 0)
+		shift = 0;
+	*cell = fdt32_to_cpu(shift);
+	return (0);
+}
+
+static int
+uart_fdt_probe(device_t dev)
+{
+	struct uart_softc *sc;
+	phandle_t node;
+	pcell_t clock, shift;
+	int err;
+
+	if (!ofw_bus_is_compatible(dev, "ns16550"))
+		return (ENXIO);
+
+	sc = device_get_softc(dev);
+	sc->sc_class = &uart_ns8250_class;
+
+	node = ofw_bus_get_node(dev);
+
+	if ((err = uart_fdt_get_clock(node, &clock)) != 0)
+		return (err);
+	uart_fdt_get_shift(node, &shift);
+
+	return (uart_bus_probe(dev, (int)shift, (int)clock, 0, 0));
+}
+
+DRIVER_MODULE(uart, simplebus, uart_fdt_driver, uart_devclass, 0, 0);
+
+/*
+ * UART console routines.
+ */
+bus_space_tag_t uart_bus_space_io;
+bus_space_tag_t uart_bus_space_mem;
+
+int
+uart_cpu_eqres(struct uart_bas *b1, struct uart_bas *b2)
+{
+
+	return ((b1->bsh == b2->bsh && b1->bst == b2->bst) ? 1 : 0);
+}
+
+int
+uart_cpu_getdev(int devtype, struct uart_devinfo *di)
+{
+	char buf[64];
+	struct uart_class *class;
+	phandle_t node, chosen;
+	pcell_t shift, br, rclk;
+	u_long start, size;
+	int err;
+
+	if (devtype != UART_DEV_CONSOLE)
+		return (ENXIO);
+
+	/*
+	 * Retrieve /chosen/std{in,out}.
+	 */
+	if ((chosen = OF_finddevice("/chosen")) == 0)
+		return (ENXIO);
+	if (OF_getprop(chosen, "stdin", buf, sizeof(buf)) <= 0)
+		return (ENXIO);
+	if ((node = OF_finddevice(buf)) == 0)
+		return (ENXIO);
+	if (OF_getprop(chosen, "stdout", buf, sizeof(buf)) <= 0)
+		return (ENXIO);
+	if (OF_finddevice(buf) != node)
+		/* Only stdin == stdout is supported. */
+		return (ENXIO);
+	/*
+	 * Retrieve serial attributes.
+	 */
+	uart_fdt_get_shift(node, &shift);
+
+	if (OF_getprop(node, "current-speed", &br, sizeof(br)) <= 0)
+		br = 0;
+	br = fdt32_to_cpu(br);
+
+	if ((err = uart_fdt_get_clock(node, &rclk)) != 0)
+		return (err);
+	/*
+	 * Finalize configuration.
+	 */
+	class = &uart_quicc_class;
+	if (fdt_is_compatible(node, "ns16550"))
+		class = &uart_ns8250_class;
+
+	di->bas.chan = 0;
+	di->bas.regshft = (u_int)shift;
+	di->baudrate = 0;
+	di->bas.rclk = (u_int)rclk;
+	di->ops = uart_getops(class);
+	di->databits = 8;
+	di->stopbits = 1;
+	di->parity = UART_PARITY_NONE;
+	di->bas.bst = fdtbus_bs_tag;
+
+	err = fdt_regsize(node, &start, &size);
+	if (err)
+		return (ENXIO);
+	start += FDT_IMMR_VA;
+
+	uart_bus_space_mem = fdtbus_bs_tag;
+	uart_bus_space_io = NULL;
+
+	if (bus_space_map(di->bas.bst, start, size, 0, &di->bas.bsh) != 0)
+		return (ENXIO);
+
+	return (0);
+}