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 CREG_CORE_IF_CLK_DIV (CREG_BASE + 0x4B8) 42 #define CREG_CORE_IF_CLK_DIV_2 0x1 43 #define CGU_BASE ARC_PERIPHERAL_BASE 44 #define CGU_PLL_STATUS (ARC_PERIPHERAL_BASE + 0x4) 45 #define CGU_PLL_CTRL (ARC_PERIPHERAL_BASE + 0x0) 46 #define CGU_PLL_STATUS_LOCK BIT(0) 47 #define CGU_PLL_STATUS_ERR BIT(1) 48 #define CGU_PLL_CTRL_1GHZ 0x3A10 49 #define HSDK_PLL_LOCK_TIMEOUT 500 50 51 #define HSDK_PLL_LOCKED() \ 52 !!(ioread32((void __iomem *) CGU_PLL_STATUS) & CGU_PLL_STATUS_LOCK) 53 54 #define HSDK_PLL_ERR() \ 55 !!(ioread32((void __iomem *) CGU_PLL_STATUS) & CGU_PLL_STATUS_ERR) 56 57 static void __init hsdk_set_cpu_freq_1ghz(void) 58 { 59 u32 timeout = HSDK_PLL_LOCK_TIMEOUT; 60 61 /* 62 * As we set cpu clock which exceeds 500MHz, the divider for the interface 63 * clock must be programmed to div-by-2. 64 */ 65 iowrite32(CREG_CORE_IF_CLK_DIV_2, (void __iomem *) CREG_CORE_IF_CLK_DIV); 66 67 /* Set cpu clock to 1GHz */ 68 iowrite32(CGU_PLL_CTRL_1GHZ, (void __iomem *) CGU_PLL_CTRL); 69 70 while (!HSDK_PLL_LOCKED() && timeout--) 71 cpu_relax(); 72 73 if (!HSDK_PLL_LOCKED() || HSDK_PLL_ERR()) 74 pr_err("Failed to setup CPU frequency to 1GHz!"); 75 } 76 77 static void __init hsdk_init_early(void) 78 { 79 /* 80 * PAE remapping for DMA clients does not work due to an RTL bug, so 81 * CREG_PAE register must be programmed to all zeroes, otherwise it 82 * will cause problems with DMA to/from peripherals even if PAE40 is 83 * not used. 84 */ 85 86 /* Default is 1, which means "PAE offset = 4GByte" */ 87 writel_relaxed(0, (void __iomem *) CREG_PAE); 88 89 /* Really apply settings made above */ 90 writel(1, (void __iomem *) CREG_PAE_UPDATE); 91 92 /* 93 * Setup CPU frequency to 1GHz. 94 * TODO: remove it after smart hsdk pll driver will be introduced. 95 */ 96 hsdk_set_cpu_freq_1ghz(); 97 } 98 99 static const char *hsdk_compat[] __initconst = { 100 "snps,hsdk", 101 NULL, 102 }; 103 104 MACHINE_START(SIMULATION, "hsdk") 105 .dt_compat = hsdk_compat, 106 .init_early = hsdk_init_early, 107 .init_per_cpu = hsdk_init_per_cpu, 108 MACHINE_END 109