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>

3 files changed, 75 insertions, 1 deletions

diff --git a/arch/sh/boards/Kconfig b/arch/sh/boards/Kconfig
index bb2cb27074e9..9c94711aa6ca 100644
--- a/arch/sh/boards/Kconfig
+++ b/arch/sh/boards/Kconfig
@@ -156,6 +156,7 @@ config SH_SDK7786
         select SYS_SUPPORTS_PCI
         select NO_IOPORT if !PCI
         select ARCH_WANT_OPTIONAL_GPIOLIB
+        select HAVE_SRAM_POOL
         help
           Select SDK7786 if configuring for a Renesas Technology Europe
           SH7786-65nm board.
diff --git a/arch/sh/boards/mach-sdk7786/Makefile b/arch/sh/boards/mach-sdk7786/Makefile
index d0f801bd8416..23ff7d4ac491 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 000000000000..c81c3abbe01c
--- /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);