1/*
2 * SDK7786 FPGA SRAM Support.
3 *
4 * Copyright (C) 2010  Paul Mundt
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License.  See the file "COPYING" in the main directory of this archive
8 * for more details.
9 */
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/init.h>
13#include <linux/kernel.h>
14#include <linux/types.h>
15#include <linux/io.h>
16#include <linux/string.h>
17#include <mach/fpga.h>
18#include <asm/sram.h>
19#include <asm/sizes.h>
20
21static int __init fpga_sram_init(void)
22{
23	unsigned long phys;
24	unsigned int area;
25	void __iomem *vaddr;
26	int ret;
27	u16 data;
28
29	/* Enable FPGA SRAM */
30	data = fpga_read_reg(LCLASR);
31	data |= LCLASR_FRAMEN;
32	fpga_write_reg(data, LCLASR);
33
34	/*
35	 * FPGA_SEL determines the area mapping
36	 */
37	area = (data & LCLASR_FPGA_SEL_MASK) >> LCLASR_FPGA_SEL_SHIFT;
38	if (unlikely(area == LCLASR_AREA_MASK)) {
39		pr_err("FPGA memory unmapped.\n");
40		return -ENXIO;
41	}
42
43	/*
44	 * The memory itself occupies a 2KiB range at the top of the area
45	 * immediately below the system registers.
46	 */
47	phys = (area << 26) + SZ_64M - SZ_4K;
48
49	/*
50	 * The FPGA SRAM resides in translatable physical space, so set
51	 * up a mapping prior to inserting it in to the pool.
52	 */
53	vaddr = ioremap(phys, SZ_2K);
54	if (unlikely(!vaddr)) {
55		pr_err("Failed remapping FPGA memory.\n");
56		return -ENXIO;
57	}
58
59	pr_info("Adding %dKiB of FPGA memory at 0x%08lx-0x%08lx "
60		"(area %d) to pool.\n",
61		SZ_2K >> 10, phys, phys + SZ_2K - 1, area);
62
63	ret = gen_pool_add(sram_pool, (unsigned long)vaddr, SZ_2K, -1);
64	if (unlikely(ret < 0)) {
65		pr_err("Failed adding memory\n");
66		iounmap(vaddr);
67		return ret;
68	}
69
70	return 0;
71}
72postcore_initcall(fpga_sram_init);
73