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>

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.

arch/sh/boards/mach-sdk7786/Makefile

-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

arch/sh/boards/mach-sdk7786/sram.c

+/*
+ * 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);

arch/sh/include/asm/sizes.h

@@ -32,6 +32,7 @@
 #define SZ_512				0x00000200
 
 #define SZ_1K                           0x00000400
+#define SZ_2K                           0x00000800
 #define SZ_4K                           0x00001000
 #define SZ_8K                           0x00002000
 #define SZ_16K                          0x00004000

arch/sh/include/mach-sdk7786/mach/fpga.h

@@ -43,8 +43,23 @@
 
 #define FAER		0x150
 #define USRGPIR		0x160
+
 /* 0x170 reserved */
+
 #define LCLASR			0x180
+#define  LCLASR_FRAMEN		BIT(15)
+
+#define  LCLASR_FPGA_SEL_SHIFT	12
+#define  LCLASR_NAND_SEL_SHIFT	8
+#define  LCLASR_NORB_SEL_SHIFT	4
+#define  LCLASR_NORA_SEL_SHIFT	0
+
+#define  LCLASR_AREA_MASK	0x7
+
+#define  LCLASR_FPGA_SEL_MASK	(LCLASR_AREA_MASK << LCLASR_FPGA_SEL_SHIFT)
+#define  LCLASR_NAND_SEL_MASK	(LCLASR_AREA_MASK << LCLASR_NAND_SEL_SHIFT)
+#define  LCLASR_NORB_SEL_MASK	(LCLASR_AREA_MASK << LCLASR_NORB_SEL_SHIFT)
+#define  LCLASR_NORA_SEL_MASK	(LCLASR_AREA_MASK << LCLASR_NORA_SEL_SHIFT)
 
 #define SBCR		0x190
 #define  SCBR_I2CMEN	BIT(0)	/* FPGA I2C master enable */