1 /* 2 * ARC HSDK Platform support code 3 * 4 * Copyright (C) 2017 Synopsys, Inc. (www.synopsys.com) 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 11 #include <linux/init.h> 12 #include <linux/smp.h> 13 #include <asm/arcregs.h> 14 #include <asm/io.h> 15 #include <asm/mach_desc.h> 16 17 #define ARC_CCM_UNUSED_ADDR 0x60000000 18 19 static void __init hsdk_init_per_cpu(unsigned int cpu) 20 { 21 /* 22 * By default ICCM is mapped to 0x7z while this area is used for 23 * kernel virtual mappings, so move it to currently unused area. 24 */ 25 if (cpuinfo_arc700[cpu].iccm.sz) 26 write_aux_reg(ARC_REG_AUX_ICCM, ARC_CCM_UNUSED_ADDR); 27 28 /* 29 * By default DCCM is mapped to 0x8z while this area is used by kernel, 30 * so move it to currently unused area. 31 */ 32 if (cpuinfo_arc700[cpu].dccm.sz) 33 write_aux_reg(ARC_REG_AUX_DCCM, ARC_CCM_UNUSED_ADDR); 34 } 35 36 #define ARC_PERIPHERAL_BASE 0xf0000000 37 #define CREG_BASE (ARC_PERIPHERAL_BASE + 0x1000) 38 #define CREG_PAE (CREG_BASE + 0x180) 39 #define CREG_PAE_UPDATE (CREG_BASE + 0x194) 40 41 #define SDIO_BASE (ARC_PERIPHERAL_BASE + 0xA000) 42 #define SDIO_UHS_REG_EXT (SDIO_BASE + 0x108) 43 #define SDIO_UHS_REG_EXT_DIV_2 (2 << 30) 44 45 static void __init hsdk_init_early(void) 46 { 47 /* 48 * PAE remapping for DMA clients does not work due to an RTL bug, so 49 * CREG_PAE register must be programmed to all zeroes, otherwise it 50 * will cause problems with DMA to/from peripherals even if PAE40 is 51 * not used. 52 */ 53 54 /* Default is 1, which means "PAE offset = 4GByte" */ 55 writel_relaxed(0, (void __iomem *) CREG_PAE); 56 57 /* Really apply settings made above */ 58 writel(1, (void __iomem *) CREG_PAE_UPDATE); 59 60 /* 61 * Switch SDIO external ciu clock divider from default div-by-8 to 62 * minimum possible div-by-2. 63 */ 64 iowrite32(SDIO_UHS_REG_EXT_DIV_2, (void __iomem *) SDIO_UHS_REG_EXT); 65 } 66 67 static const char *hsdk_compat[] __initconst = { 68 "snps,hsdk", 69 NULL, 70 }; 71 72 MACHINE_START(SIMULATION, "hsdk") 73 .dt_compat = hsdk_compat, 74 .init_early = hsdk_init_early, 75 .init_per_cpu = hsdk_init_per_cpu, 76 MACHINE_END 77