fdt: Add serial port controlled by device tree

This adds a new console serial port which is implemented by the driver
selected in the device tree.

BUG=chromium-os:11623
TEST=build and boot U-Boot on Seaboard

Change-Id: I0e41f795a78d165c2907a9f8faeeabe1a2639a18
Reviewed-on: http://gerrit.chromium.org/gerrit/958
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>

2 files changed, 180 insertions, 0 deletions

diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 7d221fc40d..6e96d7addc 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -56,6 +56,7 @@ COBJS-$(CONFIG_S3C44B0_SERIAL) += serial_s3c44b0.o
 COBJS-$(CONFIG_XILINX_UARTLITE) += serial_xuartlite.o
 COBJS-$(CONFIG_SCIF_CONSOLE) += serial_sh.o
 COBJS-$(CONFIG_USB_TTY) += usbtty.o
+COBJS-$(CONFIG_OF_CONTROL) += serial_fdt.o
 
 COBJS	:= $(sort $(COBJS-y))
 SRCS	:= $(COBJS:.o=.c)
diff --git a/drivers/serial/serial_fdt.c b/drivers/serial/serial_fdt.c
new file mode 100644
index 0000000000..eadc9b3e7f
--- /dev/null
+++ b/drivers/serial/serial_fdt.c
@@ -0,0 +1,179 @@
+/*
+ * 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
+ */
+
+/*
+ * This is a serial port provided by the flattened device tree. It works
+ * by selecting a compiled in driver according to the setting in the FDT.
+ */
+
+#include <common.h>
+#include <fdt_decode.h>
+#include <ns16550.h>
+#include <serial.h>
+#include <serial_fdt.h>
+
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/*
+ * We need these structures to be outside BSS since they are accessed before
+ * relocation.
+ */
+static struct serial_device console = {
+	"not_in_bss"
+};
+
+struct fdt_uart console_uart = {
+	-1U
+};
+
+/* Access the console - this may need to be a function */
+#define DECLARE_CONSOLE	struct fdt_uart *uart = &console_uart
+
+/* Initialize the serial port */
+static int fserial_init(void)
+{
+	DECLARE_CONSOLE;
+
+	switch (uart->compat) {
+#ifdef CONFIG_SYS_NS16550
+	case COMPAT_SERIAL_NS16550:
+		NS16550_init((NS16550_t)uart->reg, uart->divisor);
+		break;
+#endif
+	default:
+		break;
+	}
+	return 0;
+}
+
+static void fserial_putc(const char c)
+{
+	DECLARE_CONSOLE;
+
+	if (c == '\n')
+		fserial_putc('\r');
+	switch (uart->compat) {
+#ifdef CONFIG_SYS_NS16550
+	case COMPAT_SERIAL_NS16550 :
+		NS16550_putc((NS16550_t)uart->reg, c);
+		break;
+#endif
+	default:
+		break;
+	}
+}
+
+static void fserial_puts(const char *s)
+{
+	while (*s)
+		fserial_putc(*s++);
+}
+
+static int fserial_getc(void)
+{
+	DECLARE_CONSOLE;
+
+	switch (uart->compat) {
+#ifdef CONFIG_SYS_NS16550
+	case COMPAT_SERIAL_NS16550 :
+		return NS16550_getc((NS16550_t)uart->reg, uart->id);
+#endif
+	default:
+		break;
+	}
+	/* hang */
+	for (;;) ;
+}
+
+static int fserial_tstc(void)
+{
+	DECLARE_CONSOLE;
+
+	switch (uart->compat) {
+#ifdef CONFIG_SYS_NS16550
+	case COMPAT_SERIAL_NS16550 :
+		return NS16550_tstc((NS16550_t)uart->reg, uart->id);
+#endif
+	default:
+		break;
+	}
+	return 0;
+}
+
+static void fserial_setbrg(void)
+{
+	DECLARE_CONSOLE;
+
+	uart->baudrate = gd->baudrate;
+	fdt_decode_uart_calc_divisor(uart);
+	switch (uart->compat) {
+#ifdef CONFIG_SYS_NS16550
+	case COMPAT_SERIAL_NS16550 :
+		NS16550_reinit((NS16550_t)uart->reg, uart->divisor);
+		break;
+#endif
+	default:
+		break;
+	}
+}
+
+static struct serial_device *get_console(void)
+{
+	if (fdt_decode_uart_console(gd->blob, &console_uart,
+			gd->baudrate))
+		return NULL;
+	strcpy(console.name, "serial");
+	strcpy(console.ctlr, "fdt");
+	console.init = fserial_init;
+	console.uninit = NULL;
+	console.setbrg = fserial_setbrg;
+	console.getc = fserial_getc;
+	console.tstc = fserial_tstc;
+	console.putc = fserial_putc;
+	console.puts = fserial_puts;
+	return &console;
+}
+
+struct serial_device *serial_fdt_get_console_f(void)
+{
+	/* if the uart isn't already set up, do it now */
+	if (console_uart.reg == -1U)
+		return get_console();
+
+	/* otherwise just return the current information */
+	return &console;
+}
+
+
+struct serial_device *serial_fdt_get_console_r(void)
+{
+	/*
+	 * Relocation moves all our function pointers, so we need to set up
+	 * things again. This function will only be called once.
+	 *
+	 * We cannot do the -1 check as in serial_fdt_get_console_f
+	 * because it will be -1 if that function has been ever been called.
+	 * However, the function pointers set up by serial_fdt_get_console_f
+	 * will be pre-relocation values, so we must re-calculate them.
+	 */
+	return get_console();
+}