1 files changed, 69 insertions, 0 deletions
diff --git a/arch/sh/boards/mach-sdk7786/sram.c b/arch/sh/boards/mach-sdk7786/sram.c
new file mode 100644
index 000000000..7c6ca976f
--- /dev/null
+++ b/arch/sh/boards/mach-sdk7786/sram.c
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SDK7786 FPGA SRAM Support.
+ *
+ * Copyright (C) 2010  Paul Mundt
+ */
+#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 <linux/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);