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

73 lines
1.7 KiB
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);