3 files changed, 102 insertions, 1 deletions
diff --git a/arch/arm/mach-davinci/Makefile b/arch/arm/mach-davinci/Makefile
index 5b62d8a4b18..059ab78084b 100644
--- a/arch/arm/mach-davinci/Makefile
+++ b/arch/arm/mach-davinci/Makefile
@@ -5,7 +5,7 @@
 
 # Common objects
 obj-y 			:= time.o clock.o serial.o io.o psc.o \
-			   gpio.o devices.o dma.o usb.o common.o
+			   gpio.o devices.o dma.o usb.o common.o sram.o
 
 obj-$(CONFIG_DAVINCI_MUX)		+= mux.o
 
diff --git a/arch/arm/mach-davinci/include/mach/sram.h b/arch/arm/mach-davinci/include/mach/sram.h
new file mode 100644
index 00000000000..111f7cc71e0
--- /dev/null
+++ b/arch/arm/mach-davinci/include/mach/sram.h
@@ -0,0 +1,27 @@
+/*
+ * mach/sram.h - DaVinci simple SRAM allocator
+ *
+ * Copyright (C) 2009 David Brownell
+ *
+ * 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.
+ */
+#ifndef __MACH_SRAM_H
+#define __MACH_SRAM_H
+
+/* ARBITRARY:  SRAM allocations are multiples of this 2^N size */
+#define SRAM_GRANULARITY	512
+
+/*
+ * SRAM allocations return a CPU virtual address, or NULL on error.
+ * If a DMA address is requested and the SRAM supports DMA, its
+ * mapped address is also returned.
+ *
+ * Errors include SRAM memory not being available, and requesting
+ * DMA mapped SRAM on systems which don't allow that.
+ */
+extern void *sram_alloc(size_t len, dma_addr_t *dma);
+extern void sram_free(void *addr, size_t len);
+
+#endif /* __MACH_SRAM_H */
diff --git a/arch/arm/mach-davinci/sram.c b/arch/arm/mach-davinci/sram.c
new file mode 100644
index 00000000000..db54b2a66b4
--- /dev/null
+++ b/arch/arm/mach-davinci/sram.c
@@ -0,0 +1,74 @@
+/*
+ * mach-davinci/sram.c - DaVinci simple SRAM allocator
+ *
+ * Copyright (C) 2009 David Brownell
+ *
+ * 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.
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/genalloc.h>
+
+#include <mach/common.h>
+#include <mach/memory.h>
+#include <mach/sram.h>
+
+
+static struct gen_pool *sram_pool;
+
+void *sram_alloc(size_t len, dma_addr_t *dma)
+{
+	unsigned long vaddr;
+	dma_addr_t dma_base = davinci_soc_info.sram_dma;
+
+	if (dma)
+		*dma = 0;
+	if (!sram_pool || (dma && !dma_base))
+		return NULL;
+
+	vaddr = gen_pool_alloc(sram_pool, len);
+	if (!vaddr)
+		return NULL;
+
+	if (dma)
+		*dma = dma_base + (vaddr - SRAM_VIRT);
+	return (void *)vaddr;
+
+}
+EXPORT_SYMBOL(sram_alloc);
+
+void sram_free(void *addr, size_t len)
+{
+	gen_pool_free(sram_pool, (unsigned long) addr, len);
+}
+EXPORT_SYMBOL(sram_free);
+
+
+/*
+ * REVISIT This supports CPU and DMA access to/from SRAM, but it
+ * doesn't (yet?) support some other notable uses of SRAM:  as TCM
+ * for data and/or instructions; and holding code needed to enter
+ * and exit suspend states (while DRAM can't be used).
+ */
+static int __init sram_init(void)
+{
+	unsigned len = davinci_soc_info.sram_len;
+	int status = 0;
+
+	if (len) {
+		len = min(len, SRAM_SIZE);
+		sram_pool = gen_pool_create(ilog2(SRAM_GRANULARITY), -1);
+		if (!sram_pool)
+			status = -ENOMEM;
+	}
+	if (sram_pool)
+		status = gen_pool_add(sram_pool, SRAM_VIRT, len, -1);
+	WARN_ON(status < 0);
+	return status;
+}
+core_initcall(sram_init);
+