[U-Boot] [PATCH v4 01/12] omap4: utility function to identify the context of hw init

Aneesh V
2011-07-21T07:28:07Z

The basic hardware init of OMAP4(s_init()) can happen in 4
different contexts:
1. SPL running from SRAM
2. U-Boot running from FLASH
3. Non-XIP U-Boot loaded to SDRAM by SPL
4. Non-XIP U-Boot loaded to SDRAM by ROM code using the
Configuration Header feature

What level of hw initialization gets done depends on this
context. Add a utility function to find this context.

Signed-off-by: Aneesh V <aneesh@ti.com>
---
V3:
* Changed the context names to more meaningful names as
suggested by WD
---
arch/arm/include/asm/arch-omap4/sys_proto.h | 49 ++++++++++++++++++++++++++-
arch/arm/include/asm/omap_common.h | 34 ++++++++++++++++++
2 files changed, 82 insertions(+), 1 deletions(-)
create mode 100644 arch/arm/include/asm/omap_common.h

diff --git a/arch/arm/include/asm/arch-omap4/sys_proto.h b/arch/arm/include/asm/arch-omap4/sys_proto.h
index 4fa4f4b..6b596b4 100644
--- a/arch/arm/include/asm/arch-omap4/sys_proto.h
+++ b/arch/arm/include/asm/arch-omap4/sys_proto.h
@@ -23,10 +23,12 @@

#include <asm/arch/omap4.h>
#include <asm/io.h>
+#include <asm/omap_common.h>

struct omap_sysinfo {
char *board_string;
};
+extern const struct omap_sysinfo sysinfo;

void gpmc_init(void);
void watchdog_init(void);
@@ -37,6 +39,51 @@ u32 wait_on_value(u32, u32, void *, u32);
void sdelay(unsigned long);
void set_pl310_ctrl_reg(u32 val);

-extern const struct omap_sysinfo sysinfo;
+static inline u32 running_from_sdram(void)
+{
+ u32 pc;
+ asm volatile ("mov %0, pc" : "=r" (pc));
+ return ((pc >= OMAP44XX_DRAM_ADDR_SPACE_START) &&
+ (pc < OMAP44XX_DRAM_ADDR_SPACE_END));
+}
+
+static inline u8 uboot_loaded_by_spl(void)
+{
+ /*
+ * Configuration Header is not supported yet, so u-boot init running
+ * from SDRAM implies that it was loaded by SPL. When this situation
+ * changes one of these approaches could be taken:
+ * i. Pass a magic from SPL to U-Boot and U-Boot save it at a known
+ * location.
+ * ii. Check the OPP. CH can support only 50% OPP while SPL initializes
+ * the DPLLs@100% OPP.
+ */
+ return running_from_sdram();
+}
+/*
+ * The basic hardware init of OMAP(s_init()) can happen in 4
+ * different contexts:
+ * 1. SPL running from SRAM
+ * 2. U-Boot running from FLASH
+ * 3. Non-XIP U-Boot loaded to SDRAM by SPL
+ * 4. Non-XIP U-Boot loaded to SDRAM by ROM code using the
+ * Configuration Header feature
+ *
+ * This function finds this context.
+ * Defining as inline may help in compiling out unused functions in SPL
+ */
+static inline u32 omap4_hw_init_context(void)
+{
+#ifdef CONFIG_SPL_BUILD
+ return OMAP_INIT_CONTEXT_SPL;
+#else
+ if (uboot_loaded_by_spl())
+ return OMAP_INIT_CONTEXT_UBOOT_AFTER_SPL;
+ else if (running_from_sdram())
+ return OMAP_INIT_CONTEXT_UBOOT_AFTER_CH;
+ else
+ return OMAP_INIT_CONTEXT_UBOOT_FROM_NOR;
+#endif
+}

#endif
diff --git a/arch/arm/include/asm/omap_common.h b/arch/arm/include/asm/omap_common.h
new file mode 100644
index 0000000..d80f665
--- /dev/null
+++ b/arch/arm/include/asm/omap_common.h
@@ -0,0 +1,34 @@
+/*
+ * (C) Copyright 2010
+ * Texas Instruments, <www.ti.com>
+ *
+ * Aneesh V <aneesh@ti.com>
+ *
+ * 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 _OMAP_COMMON_H_
+#define _OMAP_COMMON_H_
+
+/* HW Init Context */
+#define OMAP_INIT_CONTEXT_SPL 0
+#define OMAP_INIT_CONTEXT_UBOOT_FROM_NOR 1
+#define OMAP_INIT_CONTEXT_UBOOT_AFTER_SPL 2
+#define OMAP_INIT_CONTEXT_UBOOT_AFTER_CH 3
+
+#endif /* _OMAP_COMMON_H_ */
--
1.7.0.4