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 */ 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 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