1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (c) 2013 MundoReader S.L. 4 * Author: Heiko Stuebner <heiko@sntech.de> 5 */ 6 7 #include <linux/delay.h> 8 #include <linux/init.h> 9 #include <linux/smp.h> 10 #include <linux/io.h> 11 #include <linux/of.h> 12 #include <linux/of_address.h> 13 #include <linux/regmap.h> 14 #include <linux/mfd/syscon.h> 15 16 #include <linux/reset.h> 17 #include <linux/cpu.h> 18 #include <asm/cacheflush.h> 19 #include <asm/cp15.h> 20 #include <asm/smp_scu.h> 21 #include <asm/smp_plat.h> 22 #include <asm/mach/map.h> 23 24 #include "core.h" 25 26 static void __iomem *scu_base_addr; 27 static void __iomem *sram_base_addr; 28 static int ncores; 29 30 #define PMU_PWRDN_CON 0x08 31 #define PMU_PWRDN_ST 0x0c 32 33 #define PMU_PWRDN_SCU 4 34 35 static struct regmap *pmu; 36 static int has_pmu = true; 37 static struct reset_control *cpu_rstc[4]; 38 39 static int pmu_power_domain_is_on(int pd) 40 { 41 u32 val; 42 int ret; 43 44 ret = regmap_read(pmu, PMU_PWRDN_ST, &val); 45 if (ret < 0) 46 return ret; 47 48 return !(val & BIT(pd)); 49 } 50 51 static struct reset_control *rockchip_get_core_reset(int cpu) 52 { 53 struct device *dev = get_cpu_device(cpu); 54 struct device_node *np; 55 56 /* The cpu device is only available after the initial core bringup */ 57 if (dev) 58 np = dev->of_node; 59 else 60 np = of_get_cpu_node(cpu, NULL); 61 62 return of_reset_control_get_exclusive(np, NULL); 63 } 64 65 static int pmu_set_power_domain(int pd, bool on) 66 { 67 u32 val = (on) ? 0 : BIT(pd); 68 struct reset_control *rstc; 69 int ret; 70 71 rstc = pd < ARRAY_SIZE(cpu_rstc) ? cpu_rstc[pd] : ERR_PTR(-EINVAL); 72 73 if (IS_ERR(rstc) && read_cpuid_part() != ARM_CPU_PART_CORTEX_A9) { 74 pr_err("%s: could not get reset control for core %d\n", 75 __func__, pd); 76 return PTR_ERR(rstc); 77 } 78 79 /* 80 * We need to soft reset the cpu when we turn off the cpu power domain, 81 * or else the active processors might be stalled when the individual 82 * processor is powered down. 83 */ 84 if (!IS_ERR(rstc) && !on) 85 reset_control_assert(rstc); 86 87 if (has_pmu) { 88 ret = regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), val); 89 if (ret < 0) { 90 pr_err("%s: could not update power domain\n", 91 __func__); 92 return ret; 93 } 94 95 ret = -1; 96 while (ret != on) { 97 ret = pmu_power_domain_is_on(pd); 98 if (ret < 0) { 99 pr_err("%s: could not read power domain state\n", 100 __func__); 101 return ret; 102 } 103 } 104 } 105 106 if (!IS_ERR(rstc) && on) 107 reset_control_deassert(rstc); 108 109 return 0; 110 } 111 112 /* 113 * Handling of CPU cores 114 */ 115 116 static int rockchip_boot_secondary(unsigned int cpu, struct task_struct *idle) 117 { 118 int ret; 119 120 if (!sram_base_addr || (has_pmu && !pmu)) { 121 pr_err("%s: sram or pmu missing for cpu boot\n", __func__); 122 return -ENXIO; 123 } 124 125 if (cpu >= ncores) { 126 pr_err("%s: cpu %d outside maximum number of cpus %d\n", 127 __func__, cpu, ncores); 128 return -ENXIO; 129 } 130 131 /* start the core */ 132 ret = pmu_set_power_domain(0 + cpu, true); 133 if (ret < 0) 134 return ret; 135 136 if (read_cpuid_part() != ARM_CPU_PART_CORTEX_A9) { 137 /* 138 * We communicate with the bootrom to active the cpus other 139 * than cpu0, after a blob of initialize code, they will 140 * stay at wfe state, once they are activated, they will check 141 * the mailbox: 142 * sram_base_addr + 4: 0xdeadbeaf 143 * sram_base_addr + 8: start address for pc 144 * The cpu0 need to wait the other cpus other than cpu0 entering 145 * the wfe state.The wait time is affected by many aspects. 146 * (e.g: cpu frequency, bootrom frequency, sram frequency, ...) 147 */ 148 mdelay(1); /* ensure the cpus other than cpu0 to startup */ 149 150 writel(__pa_symbol(secondary_startup), sram_base_addr + 8); 151 writel(0xDEADBEAF, sram_base_addr + 4); 152 dsb_sev(); 153 } 154 155 return 0; 156 } 157 158 /** 159 * rockchip_smp_prepare_sram - populate necessary sram block 160 * Starting cores execute the code residing at the start of the on-chip sram 161 * after power-on. Therefore make sure, this sram region is reserved and 162 * big enough. After this check, copy the trampoline code that directs the 163 * core to the real startup code in ram into the sram-region. 164 * @node: mmio-sram device node 165 */ 166 static int __init rockchip_smp_prepare_sram(struct device_node *node) 167 { 168 unsigned int trampoline_sz = &rockchip_secondary_trampoline_end - 169 &rockchip_secondary_trampoline; 170 struct resource res; 171 unsigned int rsize; 172 int ret; 173 174 ret = of_address_to_resource(node, 0, &res); 175 if (ret < 0) { 176 pr_err("%s: could not get address for node %pOF\n", 177 __func__, node); 178 return ret; 179 } 180 181 rsize = resource_size(&res); 182 if (rsize < trampoline_sz) { 183 pr_err("%s: reserved block with size 0x%x is too small for trampoline size 0x%x\n", 184 __func__, rsize, trampoline_sz); 185 return -EINVAL; 186 } 187 188 /* set the boot function for the sram code */ 189 rockchip_boot_fn = __pa_symbol(secondary_startup); 190 191 /* copy the trampoline to sram, that runs during startup of the core */ 192 memcpy_toio(sram_base_addr, &rockchip_secondary_trampoline, trampoline_sz); 193 flush_cache_all(); 194 outer_clean_range(0, trampoline_sz); 195 196 dsb_sev(); 197 198 return 0; 199 } 200 201 static const struct regmap_config rockchip_pmu_regmap_config = { 202 .name = "rockchip-pmu", 203 .reg_bits = 32, 204 .val_bits = 32, 205 .reg_stride = 4, 206 }; 207 208 static int __init rockchip_smp_prepare_pmu(void) 209 { 210 struct device_node *node; 211 void __iomem *pmu_base; 212 213 /* 214 * This function is only called via smp_ops->smp_prepare_cpu(). 215 * That only happens if a "/cpus" device tree node exists 216 * and has an "enable-method" property that selects the SMP 217 * operations defined herein. 218 */ 219 node = of_find_node_by_path("/cpus"); 220 221 pmu = syscon_regmap_lookup_by_phandle(node, "rockchip,pmu"); 222 of_node_put(node); 223 if (!IS_ERR(pmu)) 224 return 0; 225 226 pmu = syscon_regmap_lookup_by_compatible("rockchip,rk3066-pmu"); 227 if (!IS_ERR(pmu)) 228 return 0; 229 230 /* fallback, create our own regmap for the pmu area */ 231 pmu = NULL; 232 node = of_find_compatible_node(NULL, NULL, "rockchip,rk3066-pmu"); 233 if (!node) { 234 pr_err("%s: could not find pmu dt node\n", __func__); 235 return -ENODEV; 236 } 237 238 pmu_base = of_iomap(node, 0); 239 of_node_put(node); 240 if (!pmu_base) { 241 pr_err("%s: could not map pmu registers\n", __func__); 242 return -ENOMEM; 243 } 244 245 pmu = regmap_init_mmio(NULL, pmu_base, &rockchip_pmu_regmap_config); 246 if (IS_ERR(pmu)) { 247 int ret = PTR_ERR(pmu); 248 249 iounmap(pmu_base); 250 pmu = NULL; 251 pr_err("%s: regmap init failed\n", __func__); 252 return ret; 253 } 254 255 return 0; 256 } 257 258 static void __init rockchip_smp_prepare_cpus(unsigned int max_cpus) 259 { 260 struct device_node *node; 261 unsigned int i; 262 263 node = of_find_compatible_node(NULL, NULL, "rockchip,rk3066-smp-sram"); 264 if (!node) { 265 pr_err("%s: could not find sram dt node\n", __func__); 266 return; 267 } 268 269 sram_base_addr = of_iomap(node, 0); 270 if (!sram_base_addr) { 271 pr_err("%s: could not map sram registers\n", __func__); 272 of_node_put(node); 273 return; 274 } 275 276 if (has_pmu && rockchip_smp_prepare_pmu()) { 277 of_node_put(node); 278 return; 279 } 280 281 if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) { 282 /* enable the SCU power domain */ 283 pmu_set_power_domain(PMU_PWRDN_SCU, true); 284 285 of_node_put(node); 286 node = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu"); 287 if (!node) { 288 pr_err("%s: missing scu\n", __func__); 289 return; 290 } 291 292 scu_base_addr = of_iomap(node, 0); 293 if (!scu_base_addr) { 294 pr_err("%s: could not map scu registers\n", __func__); 295 of_node_put(node); 296 return; 297 } 298 299 /* 300 * While the number of cpus is gathered from dt, also get the 301 * number of cores from the scu to verify this value when 302 * booting the cores. 303 */ 304 ncores = scu_get_core_count(scu_base_addr); 305 pr_err("%s: ncores %d\n", __func__, ncores); 306 307 scu_enable(scu_base_addr); 308 } else { 309 unsigned int l2ctlr; 310 311 asm ("mrc p15, 1, %0, c9, c0, 2\n" : "=r" (l2ctlr)); 312 ncores = ((l2ctlr >> 24) & 0x3) + 1; 313 } 314 315 /* Collect cpu core reset control for each core */ 316 for (i = 0; i < ncores; i++) 317 cpu_rstc[i] = rockchip_get_core_reset(i); 318 319 /* Make sure that all cores except the first are really off */ 320 for (i = 1; i < ncores; i++) 321 pmu_set_power_domain(0 + i, false); 322 323 if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) { 324 if (rockchip_smp_prepare_sram(node)) { 325 of_node_put(node); 326 return; 327 } 328 } 329 330 of_node_put(node); 331 } 332 333 static void __init rk3036_smp_prepare_cpus(unsigned int max_cpus) 334 { 335 has_pmu = false; 336 337 rockchip_smp_prepare_cpus(max_cpus); 338 } 339 340 #ifdef CONFIG_HOTPLUG_CPU 341 static int rockchip_cpu_kill(unsigned int cpu) 342 { 343 /* 344 * We need a delay here to ensure that the dying CPU can finish 345 * executing v7_coherency_exit() and reach the WFI/WFE state 346 * prior to having the power domain disabled. 347 */ 348 mdelay(1); 349 350 pmu_set_power_domain(0 + cpu, false); 351 return 1; 352 } 353 354 static void rockchip_cpu_die(unsigned int cpu) 355 { 356 v7_exit_coherency_flush(louis); 357 while (1) 358 cpu_do_idle(); 359 } 360 #endif 361 362 static const struct smp_operations rk3036_smp_ops __initconst = { 363 .smp_prepare_cpus = rk3036_smp_prepare_cpus, 364 .smp_boot_secondary = rockchip_boot_secondary, 365 #ifdef CONFIG_HOTPLUG_CPU 366 .cpu_kill = rockchip_cpu_kill, 367 .cpu_die = rockchip_cpu_die, 368 #endif 369 }; 370 371 static const struct smp_operations rockchip_smp_ops __initconst = { 372 .smp_prepare_cpus = rockchip_smp_prepare_cpus, 373 .smp_boot_secondary = rockchip_boot_secondary, 374 #ifdef CONFIG_HOTPLUG_CPU 375 .cpu_kill = rockchip_cpu_kill, 376 .cpu_die = rockchip_cpu_die, 377 #endif 378 }; 379 380 CPU_METHOD_OF_DECLARE(rk3036_smp, "rockchip,rk3036-smp", &rk3036_smp_ops); 381 CPU_METHOD_OF_DECLARE(rk3066_smp, "rockchip,rk3066-smp", &rockchip_smp_ops); 382