1// SPDX-License-Identifier: GPL-2.0
2/*
3 * SDK7786 FPGA Support.
4 *
5 * Copyright (C) 2010  Paul Mundt
6 */
7#include <linux/init.h>
8#include <linux/io.h>
9#include <linux/bcd.h>
10#include <mach/fpga.h>
11#include <linux/sizes.h>
12
13#define FPGA_REGS_OFFSET	0x03fff800
14#define FPGA_REGS_SIZE		0x490
15
16/*
17 * The FPGA can be mapped in any of the generally available areas,
18 * so we attempt to scan for it using the fixed SRSTR read magic.
19 *
20 * Once the FPGA is located, the rest of the mapping data for the other
21 * components can be determined dynamically from its section mapping
22 * registers.
23 */
24static void __iomem *sdk7786_fpga_probe(void)
25{
26	unsigned long area;
27	void __iomem *base;
28
29	/*
30	 * Iterate over all of the areas where the FPGA could be mapped.
31	 * The possible range is anywhere from area 0 through 6, area 7
32	 * is reserved.
33	 */
34	for (area = PA_AREA0; area < PA_AREA7; area += SZ_64M) {
35		base = ioremap(area + FPGA_REGS_OFFSET, FPGA_REGS_SIZE);
36		if (!base) {
37			/* Failed to remap this area, move along. */
38			continue;
39		}
40
41		if (ioread16(base + SRSTR) == SRSTR_MAGIC)
42			return base;	/* Found it! */
43
44		iounmap(base);
45	}
46
47	return NULL;
48}
49
50void __iomem *sdk7786_fpga_base;
51
52void __init sdk7786_fpga_init(void)
53{
54	u16 version, date;
55
56	sdk7786_fpga_base = sdk7786_fpga_probe();
57	if (unlikely(!sdk7786_fpga_base)) {
58		panic("FPGA detection failed.\n");
59		return;
60	}
61
62	version = fpga_read_reg(FPGAVR);
63	date = fpga_read_reg(FPGADR);
64
65	pr_info("\tFPGA version:\t%d.%d (built on %d/%d/%d)\n",
66		bcd2bin(version >> 8) & 0xf, bcd2bin(version & 0xf),
67		((date >> 12) & 0xf) + 2000,
68		(date >> 8) & 0xf, bcd2bin(date & 0xff));
69}
70