[PATCH] powerpc: Xilinx: Fix boot with 16550 for 405 and 440
John Linn
john.linn at xilinx.com
Thu Jul 3 08:11:28 EST 2008
The following changes add processing to initialize the
Xilinx 16550 UART in the boot strap loader since a
boot loader is not used many times with the FPGA.
The wrapper was also modified to add the 440 build.
Signed-off-by: John Linn <john.linn at xilinx.com>
---
arch/powerpc/boot/Makefile | 2 +-
arch/powerpc/boot/simpleboot.c | 6 ++
arch/powerpc/boot/virtex.c | 100 ++++++++++++++++++++++++++++++++++++++++
arch/powerpc/boot/wrapper | 6 ++-
4 files changed, 112 insertions(+), 2 deletions(-)
create mode 100644 arch/powerpc/boot/virtex.c
diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index f8ffb56..1b641cf 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -66,7 +66,7 @@ src-plat := of.c cuboot-52xx.c cuboot-824x.c cuboot-83xx.c cuboot-85xx.c holly.c
fixed-head.S ep88xc.c ep405.c \
cuboot-katmai.c cuboot-rainier.c redboot-8xx.c ep8248e.c \
cuboot-warp.c cuboot-85xx-cpm2.c cuboot-yosemite.c simpleboot.c \
- virtex405-head.S
+ virtex405-head.S virtex.c
src-boot := $(src-wlib) $(src-plat) empty.c
src-boot := $(addprefix $(obj)/, $(src-boot))
diff --git a/arch/powerpc/boot/simpleboot.c b/arch/powerpc/boot/simpleboot.c
index 86cd285..c58a0da 100644
--- a/arch/powerpc/boot/simpleboot.c
+++ b/arch/powerpc/boot/simpleboot.c
@@ -23,6 +23,8 @@
BSS_STACK(4*1024);
+extern int platform_specific_init(void) __attribute__((weak));
+
void platform_init(unsigned long r3, unsigned long r4, unsigned long r5,
unsigned long r6, unsigned long r7)
{
@@ -80,5 +82,9 @@ void platform_init(unsigned long r3, unsigned long r4, unsigned long r5,
/* prepare the device tree and find the console */
fdt_init(_dtb_start);
+
+ if (platform_specific_init)
+ platform_specific_init();
+
serial_console_init();
}
diff --git a/arch/powerpc/boot/virtex.c b/arch/powerpc/boot/virtex.c
new file mode 100644
index 0000000..f622805
--- /dev/null
+++ b/arch/powerpc/boot/virtex.c
@@ -0,0 +1,100 @@
+/*
+ * The platform specific code for virtex devices since a boot loader is not
+ * always used.
+ *
+ * (C) Copyright 2008 Xilinx, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include "ops.h"
+#include "io.h"
+#include "stdio.h"
+
+#define UART_DLL 0 /* Out: Divisor Latch Low */
+#define UART_DLM 1 /* Out: Divisor Latch High */
+#define UART_FCR 2 /* Out: FIFO Control Register */
+#define UART_FCR_CLEAR_RCVR 0x02 /* Clear the RCVR FIFO */
+#define UART_FCR_CLEAR_XMIT 0x04 /* Clear the XMIT FIFO */
+#define UART_LCR 3 /* Out: Line Control Register */
+#define UART_MCR 4 /* Out: Modem Control Register */
+#define UART_MCR_RTS 0x02 /* RTS complement */
+#define UART_MCR_DTR 0x01 /* DTR complement */
+#define UART_LCR_DLAB 0x80 /* Divisor latch access bit */
+#define UART_LCR_WLEN8 0x03 /* Wordlength: 8 bits */
+
+static int virtex_ns16550_console_init(void *devp)
+{
+ unsigned char *reg_base;
+ u32 reg_shift, reg_offset, clk, spd;
+ u16 divisor;
+ int n;
+
+ if (dt_get_virtual_reg(devp, (void **)®_base, 1) < 1)
+ return -1;
+
+ n = getprop(devp, "reg-offset", ®_offset, sizeof(reg_offset));
+ if (n == sizeof(reg_offset))
+ reg_base += reg_offset;
+
+ n = getprop(devp, "reg-shift", ®_shift, sizeof(reg_shift));
+ if (n != sizeof(reg_shift))
+ reg_shift = 0;
+
+ n = getprop(devp, "current-speed", (void *)&spd, sizeof(spd));
+ if (n != sizeof(spd))
+ spd = 9600;
+
+ /* should there be a default clock rate?*/
+ n = getprop(devp, "clock-frequency", (void *)&clk, sizeof(clk));
+ if (n != sizeof(clk))
+ return -1;
+
+ divisor = clk / (16 * spd);
+
+ /* Access baud rate */
+ out_8(reg_base + (UART_LCR << reg_shift), UART_LCR_DLAB);
+
+ /* Baud rate based on input clock */
+ out_8(reg_base + (UART_DLL << reg_shift), divisor & 0xFF);
+ out_8(reg_base + (UART_DLM << reg_shift), divisor >> 8);
+
+ /* 8 data, 1 stop, no parity */
+ out_8(reg_base + (UART_LCR << reg_shift), UART_LCR_WLEN8);
+
+ /* RTS/DTR */
+ out_8(reg_base + (UART_MCR << reg_shift), UART_MCR_RTS | UART_MCR_DTR);
+
+ /* Clear transmitter and receiver */
+ out_8(reg_base + (UART_FCR << reg_shift),
+ UART_FCR_CLEAR_XMIT | UART_FCR_CLEAR_RCVR);
+ return 0;
+}
+
+/* For virtex, the kernel may be loaded without using a bootloader and if so
+ some UARTs need more setup than is provided in the normal console init
+*/
+int platform_specific_init(void)
+{
+ void *devp;
+ char devtype[MAX_PROP_LEN];
+ char path[MAX_PATH_LEN];
+
+ devp = finddevice("/chosen");
+ if (devp == NULL)
+ return -1;
+
+ if (getprop(devp, "linux,stdout-path", path, MAX_PATH_LEN) > 0) {
+ devp = finddevice(path);
+ if (devp == NULL)
+ return -1;
+
+ if ((getprop(devp, "device_type", devtype, sizeof(devtype)) > 0)
+ && !strcmp(devtype, "serial")
+ && (dt_is_compatible(devp, "ns16550")))
+ virtex_ns16550_console_init(devp);
+ }
+ return 0;
+}
diff --git a/arch/powerpc/boot/wrapper b/arch/powerpc/boot/wrapper
index d6c96d9..bd7ae29 100755
--- a/arch/powerpc/boot/wrapper
+++ b/arch/powerpc/boot/wrapper
@@ -200,7 +200,11 @@ adder875-redboot)
binary=y
;;
simpleboot-virtex405-*)
- platformo="$object/virtex405-head.o $object/simpleboot.o"
+ platformo="$object/virtex405-head.o $object/simpleboot.o $object/virtex.o"
+ binary=y
+ ;;
+simpleboot-virtex440-*)
+ platformo="$object/simpleboot.o $object/virtex.o"
binary=y
;;
esac
--
1.5.2.1
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