drivers/soc/bcm/brcmstb/biuctrl.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Broadcom STB SoCs Bus Unit Interface controls
   4  *
   5  * Copyright (C) 2015, Broadcom Corporation
   6  */
   7
   8 #define pr_fmt(fmt)     "brcmstb: " KBUILD_MODNAME ": " fmt
   9
  10 #include <linux/kernel.h>
  11 #include <linux/io.h>
  12 #include <linux/of_address.h>
  13 #include <linux/syscore_ops.h>
  14 #include <linux/soc/brcmstb/brcmstb.h>
  15
  16 #define  CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK 0x70000000
  17 #define CPU_CREDIT_REG_MCPx_READ_CRED_MASK      0xf
  18 #define CPU_CREDIT_REG_MCPx_WRITE_CRED_MASK     0xf
  19 #define CPU_CREDIT_REG_MCPx_READ_CRED_SHIFT(x)  ((x) * 8)
  20 #define CPU_CREDIT_REG_MCPx_WRITE_CRED_SHIFT(x) (((x) * 8) + 4)
  21
  22 #define CPU_MCP_FLOW_REG_MCPx_RDBUFF_CRED_SHIFT(x)      ((x) * 8)
  23 #define CPU_MCP_FLOW_REG_MCPx_RDBUFF_CRED_MASK          0xff
  24
  25 #define CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_THRESHOLD_MASK       0xf
  26 #define CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_MASK         0xf
  27 #define CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_SHIFT        4
  28 #define CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_ENABLE               BIT(8)
  29
  30 static void __iomem *cpubiuctrl_base;
  31 static bool mcp_wr_pairing_en;
  32 static const int *cpubiuctrl_regs;
  33
  34 static inline u32 cbc_readl(int reg)
  35 {
  36         int offset = cpubiuctrl_regs[reg];
  37
  38         if (offset == -1)
  39                 return (u32)-1;
  40
  41         return readl_relaxed(cpubiuctrl_base + offset);
  42 }
  43
  44 static inline void cbc_writel(u32 val, int reg)
  45 {
  46         int offset = cpubiuctrl_regs[reg];
  47
  48         if (offset == -1)
  49                 return;
  50
  51         writel(val, cpubiuctrl_base + offset);
  52 }
  53
  54 enum cpubiuctrl_regs {
  55         CPU_CREDIT_REG = 0,
  56         CPU_MCP_FLOW_REG,
  57         CPU_WRITEBACK_CTRL_REG
  58 };
  59
  60 static const int b15_cpubiuctrl_regs[] = {
  61         [CPU_CREDIT_REG] = 0x184,
  62         [CPU_MCP_FLOW_REG] = -1,
  63         [CPU_WRITEBACK_CTRL_REG] = -1,
  64 };
  65
  66 /* Odd cases, e.g: 7260A0 */
  67 static const int b53_cpubiuctrl_no_wb_regs[] = {
  68         [CPU_CREDIT_REG] = 0x0b0,
  69         [CPU_MCP_FLOW_REG] = 0x0b4,
  70         [CPU_WRITEBACK_CTRL_REG] = -1,
  71 };
  72
  73 static const int b53_cpubiuctrl_regs[] = {
  74         [CPU_CREDIT_REG] = 0x0b0,
  75         [CPU_MCP_FLOW_REG] = 0x0b4,
  76         [CPU_WRITEBACK_CTRL_REG] = 0x22c,
  77 };
  78
  79 static const int a72_cpubiuctrl_regs[] = {
  80         [CPU_CREDIT_REG] = 0x18,
  81         [CPU_MCP_FLOW_REG] = 0x1c,
  82         [CPU_WRITEBACK_CTRL_REG] = 0x20,
  83 };
  84
  85 #define NUM_CPU_BIUCTRL_REGS    3
  86
  87 static int __init mcp_write_pairing_set(void)
  88 {
  89         u32 creds = 0;
  90
  91         if (!cpubiuctrl_base)
  92                 return -1;
  93
  94         creds = cbc_readl(CPU_CREDIT_REG);
  95         if (mcp_wr_pairing_en) {
  96                 pr_info("MCP: Enabling write pairing\n");
  97                 cbc_writel(creds | CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK,
  98                            CPU_CREDIT_REG);
  99         } else if (creds & CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK) {
 100                 pr_info("MCP: Disabling write pairing\n");
 101                 cbc_writel(creds & ~CPU_CREDIT_REG_MCPx_WR_PAIRING_EN_MASK,
 102                            CPU_CREDIT_REG);
 103         } else {
 104                 pr_info("MCP: Write pairing already disabled\n");
 105         }
 106
 107         return 0;
 108 }
 109
 110 static const u32 a72_b53_mach_compat[] = {
 111         0x7211,
 112         0x7216,
 113         0x7255,
 114         0x7260,
 115         0x7268,
 116         0x7271,
 117         0x7278,
 118 };
 119
 120 static void __init mcp_a72_b53_set(void)
 121 {
 122         unsigned int i;
 123         u32 reg;
 124
 125         reg = brcmstb_get_family_id();
 126
 127         for (i = 0; i < ARRAY_SIZE(a72_b53_mach_compat); i++) {
 128                 if (BRCM_ID(reg) == a72_b53_mach_compat[i])
 129                         break;
 130         }
 131
 132         if (i == ARRAY_SIZE(a72_b53_mach_compat))
 133                 return;
 134
 135         /* Set all 3 MCP interfaces to 8 credits */
 136         reg = cbc_readl(CPU_CREDIT_REG);
 137         for (i = 0; i < 3; i++) {
 138                 reg &= ~(CPU_CREDIT_REG_MCPx_WRITE_CRED_MASK <<
 139                          CPU_CREDIT_REG_MCPx_WRITE_CRED_SHIFT(i));
 140                 reg &= ~(CPU_CREDIT_REG_MCPx_READ_CRED_MASK <<
 141                          CPU_CREDIT_REG_MCPx_READ_CRED_SHIFT(i));
 142                 reg |= 8 << CPU_CREDIT_REG_MCPx_WRITE_CRED_SHIFT(i);
 143                 reg |= 8 << CPU_CREDIT_REG_MCPx_READ_CRED_SHIFT(i);
 144         }
 145         cbc_writel(reg, CPU_CREDIT_REG);
 146
 147         /* Max out the number of in-flight Jwords reads on the MCP interface */
 148         reg = cbc_readl(CPU_MCP_FLOW_REG);
 149         for (i = 0; i < 3; i++)
 150                 reg |= CPU_MCP_FLOW_REG_MCPx_RDBUFF_CRED_MASK <<
 151                         CPU_MCP_FLOW_REG_MCPx_RDBUFF_CRED_SHIFT(i);
 152         cbc_writel(reg, CPU_MCP_FLOW_REG);
 153
 154         /* Enable writeback throttling, set timeout to 128 cycles, 256 cycles
 155          * threshold
 156          */
 157         reg = cbc_readl(CPU_WRITEBACK_CTRL_REG);
 158         reg |= CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_ENABLE;
 159         reg &= ~CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_THRESHOLD_MASK;
 160         reg &= ~(CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_MASK <<
 161                  CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_SHIFT);
 162         reg |= 8;
 163         reg |= 7 << CPU_WRITEBACK_CTRL_REG_WB_THROTTLE_TIMEOUT_SHIFT;
 164         cbc_writel(reg, CPU_WRITEBACK_CTRL_REG);
 165 }
 166
 167 static int __init setup_hifcpubiuctrl_regs(struct device_node *np)
 168 {
 169         struct device_node *cpu_dn;
 170         u32 family_id;
 171         int ret = 0;
 172
 173         cpubiuctrl_base = of_iomap(np, 0);
 174         if (!cpubiuctrl_base) {
 175                 pr_err("failed to remap BIU control base\n");
 176                 ret = -ENOMEM;
 177                 goto out;
 178         }
 179
 180         mcp_wr_pairing_en = of_property_read_bool(np, "brcm,write-pairing");
 181
 182         cpu_dn = of_get_cpu_node(0, NULL);
 183         if (!cpu_dn) {
 184                 pr_err("failed to obtain CPU device node\n");
 185                 ret = -ENODEV;
 186                 goto out;
 187         }
 188
 189         if (of_device_is_compatible(cpu_dn, "brcm,brahma-b15"))
 190                 cpubiuctrl_regs = b15_cpubiuctrl_regs;
 191         else if (of_device_is_compatible(cpu_dn, "brcm,brahma-b53"))
 192                 cpubiuctrl_regs = b53_cpubiuctrl_regs;
 193         else if (of_device_is_compatible(cpu_dn, "arm,cortex-a72"))
 194                 cpubiuctrl_regs = a72_cpubiuctrl_regs;
 195         else {
 196                 pr_err("unsupported CPU\n");
 197                 ret = -EINVAL;
 198         }
 199         of_node_put(cpu_dn);
 200
 201         family_id = brcmstb_get_family_id();
 202         if (BRCM_ID(family_id) == 0x7260 && BRCM_REV(family_id) == 0)
 203                 cpubiuctrl_regs = b53_cpubiuctrl_no_wb_regs;
 204 out:
 205         of_node_put(np);
 206         return ret;
 207 }
 208
 209 #ifdef CONFIG_PM_SLEEP
 210 static u32 cpubiuctrl_reg_save[NUM_CPU_BIUCTRL_REGS];
 211
 212 static int brcmstb_cpu_credit_reg_suspend(void)
 213 {
 214         unsigned int i;
 215
 216         if (!cpubiuctrl_base)
 217                 return 0;
 218
 219         for (i = 0; i < NUM_CPU_BIUCTRL_REGS; i++)
 220                 cpubiuctrl_reg_save[i] = cbc_readl(i);
 221
 222         return 0;
 223 }
 224
 225 static void brcmstb_cpu_credit_reg_resume(void)
 226 {
 227         unsigned int i;
 228
 229         if (!cpubiuctrl_base)
 230                 return;
 231
 232         for (i = 0; i < NUM_CPU_BIUCTRL_REGS; i++)
 233                 cbc_writel(cpubiuctrl_reg_save[i], i);
 234 }
 235
 236 static struct syscore_ops brcmstb_cpu_credit_syscore_ops = {
 237         .suspend = brcmstb_cpu_credit_reg_suspend,
 238         .resume = brcmstb_cpu_credit_reg_resume,
 239 };
 240 #endif
 241
 242
 243 static int __init brcmstb_biuctrl_init(void)
 244 {
 245         struct device_node *np;
 246         int ret;
 247
 248         /* We might be running on a multi-platform kernel, don't make this a
 249          * fatal error, just bail out early
 250          */
 251         np = of_find_compatible_node(NULL, NULL, "brcm,brcmstb-cpu-biu-ctrl");
 252         if (!np)
 253                 return 0;
 254
 255         ret = setup_hifcpubiuctrl_regs(np);
 256         if (ret)
 257                 return ret;
 258
 259         ret = mcp_write_pairing_set();
 260         if (ret) {
 261                 pr_err("MCP: Unable to disable write pairing!\n");
 262                 return ret;
 263         }
 264
 265         mcp_a72_b53_set();
 266 #ifdef CONFIG_PM_SLEEP
 267         register_syscore_ops(&brcmstb_cpu_credit_syscore_ops);
 268 #endif
 269         return 0;
 270 }
 271 early_initcall(brcmstb_biuctrl_init);