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
fpga_sram_init(void)21 static 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 }
72 postcore_initcall(fpga_sram_init);
73