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 */
sdk7786_fpga_probe(void)24 static 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
50 void __iomem *sdk7786_fpga_base;
51
sdk7786_fpga_init(void)52 void __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