1 /* 2 * Broadcom STB SoCs Bus Unit Interface controls 3 * 4 * Copyright (C) 2015, Broadcom Corporation 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 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 */ 15 16 #define pr_fmt(fmt) "brcmstb: " KBUILD_MODNAME ": " fmt 17 18 #include <linux/kernel.h> 19 #include <linux/io.h> 20 #include <linux/of_address.h> 21 #include <linux/syscore_ops.h> 22 #include <linux/soc/brcmstb/brcmstb.h> 23 24 #define CPU_CREDIT_REG_OFFSET 0x184 25 #define CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK 0x70000000 26 27 static void __iomem *cpubiuctrl_base; 28 static bool mcp_wr_pairing_en; 29 30 static int __init mcp_write_pairing_set(void) 31 { 32 u32 creds = 0; 33 34 if (!cpubiuctrl_base) 35 return -1; 36 37 creds = readl_relaxed(cpubiuctrl_base + CPU_CREDIT_REG_OFFSET); 38 if (mcp_wr_pairing_en) { 39 pr_info("MCP: Enabling write pairing\n"); 40 writel_relaxed(creds | CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK, 41 cpubiuctrl_base + CPU_CREDIT_REG_OFFSET); 42 } else if (creds & CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK) { 43 pr_info("MCP: Disabling write pairing\n"); 44 writel_relaxed(creds & ~CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK, 45 cpubiuctrl_base + CPU_CREDIT_REG_OFFSET); 46 } else { 47 pr_info("MCP: Write pairing already disabled\n"); 48 } 49 50 return 0; 51 } 52 53 static int __init setup_hifcpubiuctrl_regs(void) 54 { 55 struct device_node *np; 56 int ret = 0; 57 58 np = of_find_compatible_node(NULL, NULL, "brcm,brcmstb-cpu-biu-ctrl"); 59 if (!np) { 60 pr_err("missing BIU control node\n"); 61 return -ENODEV; 62 } 63 64 cpubiuctrl_base = of_iomap(np, 0); 65 if (!cpubiuctrl_base) { 66 pr_err("failed to remap BIU control base\n"); 67 ret = -ENOMEM; 68 goto out; 69 } 70 71 mcp_wr_pairing_en = of_property_read_bool(np, "brcm,write-pairing"); 72 out: 73 of_node_put(np); 74 return ret; 75 } 76 77 #ifdef CONFIG_PM_SLEEP 78 static u32 cpu_credit_reg_dump; /* for save/restore */ 79 80 static int brcmstb_cpu_credit_reg_suspend(void) 81 { 82 if (cpubiuctrl_base) 83 cpu_credit_reg_dump = 84 readl_relaxed(cpubiuctrl_base + CPU_CREDIT_REG_OFFSET); 85 return 0; 86 } 87 88 static void brcmstb_cpu_credit_reg_resume(void) 89 { 90 if (cpubiuctrl_base) 91 writel_relaxed(cpu_credit_reg_dump, 92 cpubiuctrl_base + CPU_CREDIT_REG_OFFSET); 93 } 94 95 static struct syscore_ops brcmstb_cpu_credit_syscore_ops = { 96 .suspend = brcmstb_cpu_credit_reg_suspend, 97 .resume = brcmstb_cpu_credit_reg_resume, 98 }; 99 #endif 100 101 102 void __init brcmstb_biuctrl_init(void) 103 { 104 int ret; 105 106 setup_hifcpubiuctrl_regs(); 107 108 ret = mcp_write_pairing_set(); 109 if (ret) { 110 pr_err("MCP: Unable to disable write pairing!\n"); 111 return; 112 } 113 114 #ifdef CONFIG_PM_SLEEP 115 register_syscore_ops(&brcmstb_cpu_credit_syscore_ops); 116 #endif 117 } 118