Define new linker set, UART_FDT_CLASS_AND_DEVICE, for registering full

(class and device) FDT UART. Define second one, UART_FDT_CLASS, for UART
class only.

This paves the way for declaring uart_class data and ofw/fdt compat data
with a uart implementation, rather than needing a big global table of
compat data and weak-symbol declarations of every existing implementation.

Differential Revision:	https://reviews.freebsd.org/D1992
Submitted by:	Michal Meloun

sys/dev/uart/uart.h

@@ -80,10 +80,6 @@ extern struct uart_class uart_vybrid_class __attribute__((weak));
 extern struct uart_class at91_usart_class __attribute__((weak));
 extern struct uart_class uart_exynos4210_class __attribute__((weak));
 
-#ifdef FDT
-struct ofw_compat_data;
-extern const struct ofw_compat_data *uart_fdt_compat_data;
-#endif
 
 #ifdef PC98
 struct uart_class *uart_pc98_getdev(u_long port);

sys/dev/uart/uart_bus_fdt.c

@@ -45,6 +45,7 @@ __FBSDID("$FreeBSD$");
 #include <dev/uart/uart.h>
 #include <dev/uart/uart_bus.h>
 #include <dev/uart/uart_cpu.h>
+#include <dev/uart/uart_cpu_fdt.h>
 
 static int uart_fdt_probe(device_t);
 
@@ -91,7 +92,7 @@ static struct ofw_compat_data compat_data[] = {
 };
 
 /* Export the compat_data table for use by the uart_cpu_fdt.c probe routine. */
-const struct ofw_compat_data *uart_fdt_compat_data = compat_data;
+UART_FDT_CLASS_AND_DEVICE(compat_data);
 
 static int
 uart_fdt_get_clock(phandle_t node, pcell_t *cell)
@@ -127,6 +128,20 @@ uart_fdt_get_shift(phandle_t node, pcell_t *cell)
 	return (0);
 }
 
+static uintptr_t
+uart_fdt_find_device(device_t dev)
+{
+	struct ofw_compat_data **cd;
+	const struct ofw_compat_data *ocd;
+
+	SET_FOREACH(cd, uart_fdt_class_and_device_set) {
+		ocd = ofw_bus_search_compatible(dev, *cd);
+		if (ocd->ocd_data != 0)
+			return (ocd->ocd_data);
+	}
+	return (0);
+}
+
 static int
 uart_fdt_probe(device_t dev)
 {
@@ -134,19 +149,16 @@ uart_fdt_probe(device_t dev)
 	phandle_t node;
 	pcell_t clock, shift;
 	int err;
-	const struct ofw_compat_data * cd;
 
 	sc = device_get_softc(dev);
 
 	if (!ofw_bus_status_okay(dev))
 		return (ENXIO);
 
-	cd = ofw_bus_search_compatible(dev, compat_data);
-	if (cd->ocd_data == (uintptr_t)NULL)
+	sc->sc_class = (struct uart_class *)uart_fdt_find_device(dev);
+	if (sc->sc_class == NULL)
 		return (ENXIO);
 
-	sc->sc_class = (struct uart_class *)cd->ocd_data;
-
 	node = ofw_bus_get_node(dev);
 
 	if ((err = uart_fdt_get_clock(node, &clock)) != 0)

sys/dev/uart/uart_cpu_fdt.c

@@ -50,6 +50,7 @@ __FBSDID("$FreeBSD$");
 #include <dev/uart/uart.h>
 #include <dev/uart/uart_bus.h>
 #include <dev/uart/uart_cpu.h>
+#include <dev/uart/uart_cpu_fdt.h>
 
 /*
  * UART console routines.
@@ -115,13 +116,46 @@ phandle_chosen_propdev(phandle_t chosen, const char *name, phandle_t *node)
 	return (0);
 }
 
+static const struct ofw_compat_data *
+uart_fdt_find_compatible(phandle_t node, const struct ofw_compat_data *cd)
+{
+	const struct ofw_compat_data *ocd;
+
+	for (ocd = cd; ocd->ocd_str != NULL; ocd++) {
+		if (fdt_is_compatible(node, ocd->ocd_str))
+			return (ocd);
+	}
+	return (NULL);
+}
+
+static uintptr_t
+uart_fdt_find_by_node(phandle_t node, int class_list)
+{
+	struct ofw_compat_data **cd;
+	const struct ofw_compat_data *ocd;
+
+	if (class_list) {
+		SET_FOREACH(cd, uart_fdt_class_set) {
+			ocd = uart_fdt_find_compatible(node, *cd);
+			if ((ocd != NULL) && (ocd->ocd_data != 0))
+				return (ocd->ocd_data);
+		}
+	} else {
+		SET_FOREACH(cd, uart_fdt_class_and_device_set) {
+			ocd = uart_fdt_find_compatible(node, *cd);
+			if ((ocd != NULL) && (ocd->ocd_data != 0))
+				return (ocd->ocd_data);
+		}
+	}
+	return (0);
+}
+
 int
 uart_cpu_getdev(int devtype, struct uart_devinfo *di)
 {
 	const char *propnames[] = {"stdout-path", "linux,stdout-path", "stdout",
 	    "stdin-path", "stdin", NULL};
 	const char **name;
-	const struct ofw_compat_data *cd;
 	struct uart_class *class;
 	phandle_t node, chosen;
 	pcell_t shift, br, rclk;
@@ -160,24 +194,32 @@ uart_cpu_getdev(int devtype, struct uart_devinfo *di)
 	 * 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);
+	else
+		br = fdt32_to_cpu(br);
+
+	/*
+	 * Check old style of UART definition first. Unfortunately, the common
+	 * FDT processing is not possible if we have clock, power domains and
+	 * pinmux stuff.
+	 */
+	class = (struct uart_class *)uart_fdt_find_by_node(node, 0);
+	if (class != NULL) {
+		if ((err = uart_fdt_get_clock(node, &rclk)) != 0)
+			return (err);
+	} else {
+		/* Check class only linker set */
+		class =
+		    (struct uart_class *)uart_fdt_find_by_node(node, 1);
+		if (class == NULL)
+			return (ENXIO);
+		rclk = 0;
+	}
 
-	if ((err = uart_fdt_get_clock(node, &rclk)) != 0)
-		return (err);
 	/*
 	 * Finalize configuration.
 	 */
-	for (cd = uart_fdt_compat_data; cd->ocd_str != NULL; ++cd) {
-		if (fdt_is_compatible(node, cd->ocd_str))
-			break;
-	}
-	if (cd->ocd_str == NULL)
-		return (ENXIO);
-	class = (struct uart_class *)cd->ocd_data;
-
 	di->bas.chan = 0;
 	di->bas.regshft = (u_int)shift;
 	di->baudrate = br;

sys/dev/uart/uart_cpu_fdt.h

@@ -0,0 +1,54 @@
+/*-
+ * Copyright 2015 Michal Meloun
+ * 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 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _DEV_UART_CPU_FDT_H_
+#define _DEV_UART_CPU_FDT_H_
+
+#include <sys/linker_set.h>
+
+#include <dev/ofw/ofw_bus_subr.h>
+
+/*
+ * If your UART driver implements only uart_class and uses uart_cpu_fdt.c
+ * for device instantiation, then use UART_FDT_CLASS_AND_DEVICE for its
+ * declaration
+ */
+SET_DECLARE(uart_fdt_class_and_device_set, struct ofw_compat_data );
+#define UART_FDT_CLASS_AND_DEVICE(data)				\
+	DATA_SET(uart_fdt_class_and_device_set, data)
+
+/*
+ * If your UART driver implements uart_class and custom device layer,
+ * then use UART_FDT_CLASS for its declaration
+ */
+SET_DECLARE(uart_fdt_class_set, struct ofw_compat_data );
+#define UART_FDT_CLASS(data)				\
+	DATA_SET(uart_fdt_class_set, data)
+
+
+#endif /* _DEV_UART_CPU_FDT_H_ */