arch/arm/mach-rockchip/platsmp.c

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