WIP: fdt: Add serial port controlled by device tree

new file mode 100644
index 0000000..2541147
@@ -0,0 +1,214 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <serial.h>
+#include <libfdt.h>
+#include <fdt_support.h>
+#include <fdt_decode.h>
+
+/*
+ * Here are the type we know about. One day we might allow drivers to
+ * register. For now we just put them here.
+ */
+static struct fdt_compat compat_types[] = {
+	{ COMPAT_UNKNOWN, "<none>" },
+	{ COMPAT_SPI_UART_SWITCH, "spi-uart-select" },
+	{ COMPAT_SERIAL_NS16550, "ns16550" },
+};
+
+/**
+ * Look in the FDT for an alias with the given name and return its node.
+ *
+ * @param blob	FDT blob
+ * @param name	alias name to look up
+ * @return node offset if found, or an error code < 0 otherwise
+ */
+static int find_alias_node(const void *blob, const char *name)
+{
+	const char *path;
+	int alias_node;
+
+	alias_node = fdt_path_offset(blob, "/aliases");
+	if (alias_node < 0)
+		return alias_node;
+	path = fdt_getprop(blob, alias_node, name, NULL);
+	if (!path)
+		return -FDT_ERR_NOTFOUND;
+	return fdt_path_offset(blob, path);
+}
+
+/**
+ * Look up an address property in a node and return it as an address.
+ * The property must hold exactly one address with no trailing data.
+ * This is only tested on 32-bit machines.
+ *
+ * @param blob	FDT blob
+ * @param node	node to examine
+ * @param prop_name	name of property to find
+ * @return address, if found, or ADDR_T_NONE if not
+ */
+static addr_t get_addr(const void *blob, int node, const char *prop_name)
+{
+	const addr_t *cell;
+	int len;
+
+	cell = fdt_getprop(blob, node, prop_name, &len);
+	if (cell && len != sizeof(addr_t))
+		return addr_to_cpu(*cell);
+	return ADDR_T_NONE;
+}
+
+/**
+ * Look up a 32-bit integer property in a node and return it. The property
+ * must have@least 4 bytes of data. The value of the first cell is
+ * returned.
+ *
+ * @param blob	FDT blob
+ * @param node	node to examine
+ * @param prop_name	name of property to find
+ * @param default_val	default value to return if the property is not found
+ * @return integer value, if found, or default_val if not
+ */
+static s32 get_int(const void *blob, int node, const char *prop_name,
+		s32 default_val)
+{
+	const s32 *cell;
+	int len;
+
+	cell = fdt_getprop(blob, node, prop_name, &len);
+	if (cell && len >= sizeof(s32))
+		return fdt32_to_cpu(cell[0]);
+	return default_val;
+}
+
+/**
+ * Look up a phandle and follow it to its node. Then return the offset
+ * of that node.
+ *
+ * @param blob		FDT blob
+ * @param node		node to examine
+ * @param prop_name	name of property to find
+ * @return node offset if found, -ve error code on error
+ */
+static int lookup_phandle(const void *blob, int node, const char *prop_name)
+{
+	const u32 *phandle;
+	int lookup;
+
+	phandle = fdt_getprop(blob, node, prop_name, NULL);
+	if (!phandle)
+		return -FDT_ERR_NOTFOUND;
+
+	lookup = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*phandle));
+	return lookup;
+}
+
+/**
+ * Checks whether a node is enabled.
+ * This looks for a 'status' property. If this exists, then returns 1 if
+ * the status is 'ok' and 0 otherwise. If there is no status property,
+ * it returns the default value.
+ *
+ * @param blob	FDT blob
+ * @param node	node to examine
+ * @param default_val	default value to return if no 'status' property exists
+ * @return integer value 0/1, if found, or default_val if not
+ */
+static int get_is_enabled(const void *blob, int node, int default_val)
+{
+	const char *cell;
+
+	cell = fdt_getprop(blob, node, "status", NULL);
+	if (cell)
+		return 0 == strcmp(cell, "ok");
+	return default_val;
+}
+
+void fdt_decode_uart_calc_divisor(struct fdt_uart *uart)
+{
+	if (uart->multiplier && uart->baudrate)
+		uart->divisor = (uart->clock_freq +
+				(uart->baudrate * (uart->multiplier / 2))) /
+			(uart->multiplier * uart->baudrate);
+}
+
+int fdt_decode_uart_console(const void *blob, struct fdt_uart *uart,
+		int default_baudrate)
+{
+	int node;
+
+	node = find_alias_node(blob, "console");
+	if (node < 0)
+		return node;
+	uart->reg = get_addr(blob, node, "reg");
+	uart->id = get_int(blob, node, "id", 0);
+	uart->reg_shift = get_int(blob, node, "reg_shift", 2);
+	uart->baudrate = get_int(blob, node, "baudrate", default_baudrate);
+	uart->clock_freq = get_int(blob, node, "clock-frequency", -1);
+	uart->multiplier = get_int(blob, node, "multiplier", 16);
+	uart->divisor = get_int(blob, node, "divisor", -1);
+	uart->enabled = get_is_enabled(blob, node, 1);
+	uart->interrupt = get_int(blob, node, "interrupts", -1);
+	uart->silent = get_int(blob, node, "silent", 0);
+	uart->compat = fdt_decode_lookup(blob, node);
+
+	/* Calculate divisor if required */
+	if (uart->divisor == -1)
+		fdt_decode_uart_calc_divisor(uart);
+	return 0;
+}
+
+enum fdt_compat_id fdt_decode_lookup(const void *blob, int node)
+{
+	enum fdt_compat_id id;
+
+	/* Search our drivers */
+	for (id = COMPAT_UNKNOWN; id < COMPAT_COUNT; id++)
+		if (0 == fdt_node_check_compatible(blob, node,
+				compat_types[id].name))
+			return id;
+	return COMPAT_UNKNOWN;
+}
+
+int fdt_decode_get_spi_switch(const void *blob, struct fdt_spi_uart *config)
+{
+	int node, uart_node;
+	const u32 *gpio;
+
+	node = fdt_node_offset_by_compatible(blob, 0,
+					     "nvidia,spi-uart-switch");
+	if (node < 0)
+		return node;
+
+	uart_node = lookup_phandle(blob, node, "uart");
+	if (uart_node < 0)
+		return uart_node;
+	config->port = get_int(blob, uart_node, "id", -1);
+	if (config->port == -1)
+		return -FDT_ERR_NOTFOUND;
+	config->gpio = -1;
+	config->regs = (NS16550_t)get_addr(blob, uart_node, "reg");
+	gpio = fdt_getprop(blob, node, "gpios", NULL);
+	if (gpio)
+		config->gpio = fdt32_to_cpu(gpio[1]);
+	return 0;
+}

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index d871cdd..e7e8d84 100644
@@ -57,6 +57,7 @@ struct fdt_memory {
  */
 enum fdt_compat_id {
 	COMPAT_UNKNOWN,
+	COMPAT_SERIAL_NS16550,
 
 	COMPAT_COUNT,
 };

new file mode 100644
index 0000000..c53e0a5
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+
+/*
+ * Provides a serial port defined by an FDT. This makes calls to the
+ * driver selected by the FDT.
+ */
+
+/**
+ * Return a pointer to the serial console device before relocation.
+ */
+struct serial_device *serial_fdt_get_console_f(void);
+
+/**
+ * Return a pointer to the serial console device after relocation.
+ */
+struct serial_device *serial_fdt_get_console_r(void);

index 0f87163..d9cb1ad 100644
@@ -33,6 +33,7 @@ DECLARE_GLOBAL_DATA_PTR;
  */
 #define COMPAT(id, name) name
 static const char * const compat_names[COMPAT_COUNT] = {
+	COMPAT(SERIAL_NS16550, "ns16550"),
 };
 
 /**