[U-Boot] [PATCH 5/5 v1] integrator: make flash writeable on boot

[Linus Walleij]

This reconfigures the EBI (External Bus Interface) on the
integrator so that chip select 1, handling the flash memory, is
set to writeable. Without this it is not possible for U-Boot to
access flash memory and it crashes on startup since CFI won't
work properly.

Since this is the first time we use the EBI, we create a header
file for its registers.

Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
---
 board/armltd/integrator/integrator.c |   15 ++++++++
 include/arm-ebi.h                    |   62 ++++++++++++++++++++++++++++++++++
 2 files changed, 77 insertions(+), 0 deletions(-)
 create mode 100644 include/arm-ebi.h

diff --git a/board/armltd/integrator/integrator.c b/board/armltd/integrator/integrator.c
index 780218c..44e69f1 100644
--- a/board/armltd/integrator/integrator.c
+++ b/board/armltd/integrator/integrator.c
@@ -35,6 +35,7 @@
 
 #include <common.h>
 #include <netdev.h>
+#include <arm-ebi.h>
 #include <asm/io.h>
 
 DECLARE_GLOBAL_DATA_PTR;
@@ -56,6 +57,8 @@ void show_boot_progress(int progress)
 
 int board_init (void)
 {
+	u32 val;
+
 	/* arch number of Integrator Board */
 #ifdef CONFIG_ARCH_CINTEGRATOR
 	gd->bd->bi_arch_number = MACH_TYPE_CINTEGRATOR;
@@ -73,6 +76,18 @@ extern void cm_remap(void);
 	cm_remap();	/* remaps writeable memory to 0x00000000 */
 #endif
 
+	/*
+	 * The system comes up with the flash memory non-writable and
+	 * configuration locked. If we want U-Boot to be used for flash
+	 * access we cannot have the flash memory locked.
+	 */
+	writel(EBI_UNLOCK_MAGIC, EBI_BASE + EBI_LOCK_REG);
+	val = readl(EBI_BASE + EBI_CSR1_REG);
+	val &= EBI_CSR_WREN_MASK;
+	val |= EBI_CSR_WREN_ENABLE;
+	writel(val, EBI_BASE + EBI_CSR1_REG);
+	writel(0, EBI_BASE + EBI_LOCK_REG);
+
 	icache_enable ();
 
 	return 0;
diff --git a/include/arm-ebi.h b/include/arm-ebi.h
new file mode 100644
index 0000000..2d85e3f
--- /dev/null
+++ b/include/arm-ebi.h
@@ -0,0 +1,62 @@
+/*
+ * (C) Copyright 2011
+ * Linaro
+ * Linus Walleij <linus.walleij at linaro.org>
+ * Register definitions for the External Bus Interface (EBI)
+ * found in the ARM Integrator AP and CP reference designs
+ *
+ * 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
+ */
+
+#ifndef __ARM_EBI_H
+#define __ARM_EBI_H
+
+#define EBI_BASE		0x12000000
+
+#define EBI_CSR0_REG		0x00 /* CS0 = Boot ROM */
+#define EBI_CSR1_REG		0x04 /* CS1 = Flash */
+#define EBI_CSR2_REG		0x08 /* CS2 = SSRAM */
+#define EBI_CSR3_REG		0x0C /* CS3 = Expansion memory */
+/*
+ * The four upper bits are the waitstates for each chip select
+ * 0x00 = 2 cycles, 0x10 = 3 cycles, ... 0xe0 = 16 cycles, 0xf0 = 16 cycles
+ */
+#define EBI_CSR_WAIT_MASK	0xF0
+/* Whether memory is synchronous or asynchronous */
+#define EBI_CSR_SYNC_MASK	0xF7
+#define EBI_CSR_ASYNC		0x00
+#define EBI_CSR_SYNC		0x08
+/* Whether memory is write enabled or not */
+#define EBI_CSR_WREN_MASK	0xFB
+#define EBI_CSR_WREN_DISABLE	0x00
+#define EBI_CSR_WREN_ENABLE	0x04
+/* Memory bit width for each chip select */
+#define EBI_CSR_MEMSIZE_MASK	0xFC
+#define EBI_CSR_MEMSIZE_8BIT	0x00
+#define EBI_CSR_MEMSIZE_16BIT	0x01
+#define EBI_CSR_MEMSIZE_32BIT	0x02
+
+/*
+ * The lock register need to be written with 0xa05f before anything in the
+ * EBI can be changed.
+ */
+#define EBI_LOCK_REG		0x20
+#define EBI_UNLOCK_MAGIC	0xA05F
+
+#endif
-- 
1.7.6