sh: mach-sdk7786: Add support for the FPGA SRAM.

This ties in the 2KiB of FPGA SRAM in to the generic SRAM pool.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

2 files changed, 74 insertions, 1 deletions

diff --git a/arch/sh/boards/mach-sdk7786/Makefile b/arch/sh/boards/mach-sdk7786/Makefile
index d0f801bd841..23ff7d4ac49 100644
--- a/arch/sh/boards/mach-sdk7786/Makefile
+++ b/arch/sh/boards/mach-sdk7786/Makefile
@@ -1,3 +1,4 @@
-obj-y	:= setup.o fpga.o irq.o
+obj-y	:= fpga.o irq.o setup.o
 
 obj-$(CONFIG_GENERIC_GPIO)	+= gpio.o
+obj-$(CONFIG_HAVE_SRAM_POOL)	+= sram.o
diff --git a/arch/sh/boards/mach-sdk7786/sram.c b/arch/sh/boards/mach-sdk7786/sram.c
new file mode 100644
index 00000000000..c81c3abbe01
--- /dev/null
+++ b/arch/sh/boards/mach-sdk7786/sram.c
@@ -0,0 +1,72 @@
+/*
+ * SDK7786 FPGA SRAM Support.
+ *
+ * Copyright (C) 2010  Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/io.h>
+#include <linux/string.h>
+#include <mach/fpga.h>
+#include <asm/sram.h>
+#include <asm/sizes.h>
+
+static int __init fpga_sram_init(void)
+{
+	unsigned long phys;
+	unsigned int area;
+	void __iomem *vaddr;
+	int ret;
+	u16 data;
+
+	/* Enable FPGA SRAM */
+	data = fpga_read_reg(LCLASR);
+	data |= LCLASR_FRAMEN;
+	fpga_write_reg(data, LCLASR);
+
+	/*
+	 * FPGA_SEL determines the area mapping
+	 */
+	area = (data & LCLASR_FPGA_SEL_MASK) >> LCLASR_FPGA_SEL_SHIFT;
+	if (unlikely(area == LCLASR_AREA_MASK)) {
+		pr_err("FPGA memory unmapped.\n");
+		return -ENXIO;
+	}
+
+	/*
+	 * The memory itself occupies a 2KiB range at the top of the area
+	 * immediately below the system registers.
+	 */
+	phys = (area << 26) + SZ_64M - SZ_4K;
+
+	/*
+	 * The FPGA SRAM resides in translatable physical space, so set
+	 * up a mapping prior to inserting it in to the pool.
+	 */
+	vaddr = ioremap(phys, SZ_2K);
+	if (unlikely(!vaddr)) {
+		pr_err("Failed remapping FPGA memory.\n");
+		return -ENXIO;
+	}
+
+	pr_info("Adding %dKiB of FPGA memory at 0x%08lx-0x%08lx "
+		"(area %d) to pool.\n",
+		SZ_2K >> 10, phys, phys + SZ_2K - 1, area);
+
+	ret = gen_pool_add(sram_pool, (unsigned long)vaddr, SZ_2K, -1);
+	if (unlikely(ret < 0)) {
+		pr_err("Failed adding memory\n");
+		iounmap(vaddr);
+		return ret;
+	}
+
+	return 0;
+}
+postcore_initcall(fpga_sram_init);