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 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