hw/misc/imx6_src.c

   1 /*
   2  * IMX6 System Reset Controller
   3  *
   4  * Copyright (c) 2015 Jean-Christophe Dubois <jcd@tribudubois.net>
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   7  * See the COPYING file in the top-level directory.
   8  *
   9  */
  10
  11 #include "qemu/osdep.h"
  12 #include "hw/misc/imx6_src.h"
  13 #include "migration/vmstate.h"
  14 #include "qemu/bitops.h"
  15 #include "qemu/log.h"
  16 #include "qemu/main-loop.h"
  17 #include "qemu/module.h"
  18 #include "arm-powerctl.h"
  19 #include "hw/core/cpu.h"
  20
  21 #ifndef DEBUG_IMX6_SRC
  22 #define DEBUG_IMX6_SRC 0
  23 #endif
  24
  25 #define DPRINTF(fmt, args...) \
  26     do { \
  27         if (DEBUG_IMX6_SRC) { \
  28             fprintf(stderr, "[%s]%s: " fmt , TYPE_IMX6_SRC, \
  29                                              __func__, ##args); \
  30         } \
  31     } while (0)
  32
  33 static const char *imx6_src_reg_name(uint32_t reg)
  34 {
  35     static char unknown[20];
  36
  37     switch (reg) {
  38     case SRC_SCR:
  39         return "SRC_SCR";
  40     case SRC_SBMR1:
  41         return "SRC_SBMR1";
  42     case SRC_SRSR:
  43         return "SRC_SRSR";
  44     case SRC_SISR:
  45         return "SRC_SISR";
  46     case SRC_SIMR:
  47         return "SRC_SIMR";
  48     case SRC_SBMR2:
  49         return "SRC_SBMR2";
  50     case SRC_GPR1:
  51         return "SRC_GPR1";
  52     case SRC_GPR2:
  53         return "SRC_GPR2";
  54     case SRC_GPR3:
  55         return "SRC_GPR3";
  56     case SRC_GPR4:
  57         return "SRC_GPR4";
  58     case SRC_GPR5:
  59         return "SRC_GPR5";
  60     case SRC_GPR6:
  61         return "SRC_GPR6";
  62     case SRC_GPR7:
  63         return "SRC_GPR7";
  64     case SRC_GPR8:
  65         return "SRC_GPR8";
  66     case SRC_GPR9:
  67         return "SRC_GPR9";
  68     case SRC_GPR10:
  69         return "SRC_GPR10";
  70     default:
  71         sprintf(unknown, "%u ?", reg);
  72         return unknown;
  73     }
  74 }
  75
  76 static const VMStateDescription vmstate_imx6_src = {
  77     .name = TYPE_IMX6_SRC,
  78     .version_id = 1,
  79     .minimum_version_id = 1,
  80     .fields = (VMStateField[]) {
  81         VMSTATE_UINT32_ARRAY(regs, IMX6SRCState, SRC_MAX),
  82         VMSTATE_END_OF_LIST()
  83     },
  84 };
  85
  86 static void imx6_src_reset(DeviceState *dev)
  87 {
  88     IMX6SRCState *s = IMX6_SRC(dev);
  89
  90     DPRINTF("\n");
  91
  92     memset(s->regs, 0, sizeof(s->regs));
  93
  94     /* Set reset values */
  95     s->regs[SRC_SCR] = 0x521;
  96     s->regs[SRC_SRSR] = 0x1;
  97     s->regs[SRC_SIMR] = 0x1F;
  98 }
  99
 100 static uint64_t imx6_src_read(void *opaque, hwaddr offset, unsigned size)
 101 {
 102     uint32_t value = 0;
 103     IMX6SRCState *s = (IMX6SRCState *)opaque;
 104     uint32_t index = offset >> 2;
 105
 106     if (index < SRC_MAX) {
 107         value = s->regs[index];
 108     } else {
 109         qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
 110                       HWADDR_PRIx "\n", TYPE_IMX6_SRC, __func__, offset);
 111
 112     }
 113
 114     DPRINTF("reg[%s] => 0x%" PRIx32 "\n", imx6_src_reg_name(index), value);
 115
 116     return value;
 117 }
 118
 119
 120 /* The reset is asynchronous so we need to defer clearing the reset
 121  * bit until the work is completed.
 122  */
 123
 124 struct SRCSCRResetInfo {
 125     IMX6SRCState *s;
 126     int reset_bit;
 127 };
 128
 129 static void imx6_clear_reset_bit(CPUState *cpu, run_on_cpu_data data)
 130 {
 131     struct SRCSCRResetInfo *ri = data.host_ptr;
 132     IMX6SRCState *s = ri->s;
 133
 134     assert(qemu_mutex_iothread_locked());
 135
 136     s->regs[SRC_SCR] = deposit32(s->regs[SRC_SCR], ri->reset_bit, 1, 0);
 137     DPRINTF("reg[%s] <= 0x%" PRIx32 "\n",
 138             imx6_src_reg_name(SRC_SCR), s->regs[SRC_SCR]);
 139
 140     g_free(ri);
 141 }
 142
 143 static void imx6_defer_clear_reset_bit(int cpuid,
 144                                        IMX6SRCState *s,
 145                                        unsigned long reset_shift)
 146 {
 147     struct SRCSCRResetInfo *ri;
 148     CPUState *cpu = arm_get_cpu_by_id(cpuid);
 149
 150     if (!cpu) {
 151         return;
 152     }
 153
 154     ri = g_malloc(sizeof(struct SRCSCRResetInfo));
 155     ri->s = s;
 156     ri->reset_bit = reset_shift;
 157
 158     async_run_on_cpu(cpu, imx6_clear_reset_bit, RUN_ON_CPU_HOST_PTR(ri));
 159 }
 160
 161
 162 static void imx6_src_write(void *opaque, hwaddr offset, uint64_t value,
 163                            unsigned size)
 164 {
 165     IMX6SRCState *s = (IMX6SRCState *)opaque;
 166     uint32_t index = offset >> 2;
 167     unsigned long change_mask;
 168     unsigned long current_value = value;
 169
 170     if (index >=  SRC_MAX) {
 171         qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
 172                       HWADDR_PRIx "\n", TYPE_IMX6_SRC, __func__, offset);
 173         return;
 174     }
 175
 176     DPRINTF("reg[%s] <= 0x%" PRIx32 "\n", imx6_src_reg_name(index),
 177             (uint32_t)current_value);
 178
 179     change_mask = s->regs[index] ^ (uint32_t)current_value;
 180
 181     switch (index) {
 182     case SRC_SCR:
 183         /*
 184          * On real hardware when the system reset controller starts a
 185          * secondary CPU it runs through some boot ROM code which reads
 186          * the SRC_GPRX registers controlling the start address and branches
 187          * to it.
 188          * Here we are taking a short cut and branching directly to the
 189          * requested address (we don't want to run the boot ROM code inside
 190          * QEMU)
 191          */
 192         if (EXTRACT(change_mask, CORE3_ENABLE)) {
 193             if (EXTRACT(current_value, CORE3_ENABLE)) {
 194                 /* CORE 3 is brought up */
 195                 arm_set_cpu_on(3, s->regs[SRC_GPR7], s->regs[SRC_GPR8],
 196                                3, false);
 197             } else {
 198                 /* CORE 3 is shut down */
 199                 arm_set_cpu_off(3);
 200             }
 201             /* We clear the reset bits as the processor changed state */
 202             imx6_defer_clear_reset_bit(3, s, CORE3_RST_SHIFT);
 203             clear_bit(CORE3_RST_SHIFT, &change_mask);
 204         }
 205         if (EXTRACT(change_mask, CORE2_ENABLE)) {
 206             if (EXTRACT(current_value, CORE2_ENABLE)) {
 207                 /* CORE 2 is brought up */
 208                 arm_set_cpu_on(2, s->regs[SRC_GPR5], s->regs[SRC_GPR6],
 209                                3, false);
 210             } else {
 211                 /* CORE 2 is shut down */
 212                 arm_set_cpu_off(2);
 213             }
 214             /* We clear the reset bits as the processor changed state */
 215             imx6_defer_clear_reset_bit(2, s, CORE2_RST_SHIFT);
 216             clear_bit(CORE2_RST_SHIFT, &change_mask);
 217         }
 218         if (EXTRACT(change_mask, CORE1_ENABLE)) {
 219             if (EXTRACT(current_value, CORE1_ENABLE)) {
 220                 /* CORE 1 is brought up */
 221                 arm_set_cpu_on(1, s->regs[SRC_GPR3], s->regs[SRC_GPR4],
 222                                3, false);
 223             } else {
 224                 /* CORE 1 is shut down */
 225                 arm_set_cpu_off(1);
 226             }
 227             /* We clear the reset bits as the processor changed state */
 228             imx6_defer_clear_reset_bit(1, s, CORE1_RST_SHIFT);
 229             clear_bit(CORE1_RST_SHIFT, &change_mask);
 230         }
 231         if (EXTRACT(change_mask, CORE0_RST)) {
 232             arm_reset_cpu(0);
 233             imx6_defer_clear_reset_bit(0, s, CORE0_RST_SHIFT);
 234         }
 235         if (EXTRACT(change_mask, CORE1_RST)) {
 236             arm_reset_cpu(1);
 237             imx6_defer_clear_reset_bit(1, s, CORE1_RST_SHIFT);
 238         }
 239         if (EXTRACT(change_mask, CORE2_RST)) {
 240             arm_reset_cpu(2);
 241             imx6_defer_clear_reset_bit(2, s, CORE2_RST_SHIFT);
 242         }
 243         if (EXTRACT(change_mask, CORE3_RST)) {
 244             arm_reset_cpu(3);
 245             imx6_defer_clear_reset_bit(3, s, CORE3_RST_SHIFT);
 246         }
 247         if (EXTRACT(change_mask, SW_IPU2_RST)) {
 248             /* We pretend the IPU2 is reset */
 249             clear_bit(SW_IPU2_RST_SHIFT, &current_value);
 250         }
 251         if (EXTRACT(change_mask, SW_IPU1_RST)) {
 252             /* We pretend the IPU1 is reset */
 253             clear_bit(SW_IPU1_RST_SHIFT, &current_value);
 254         }
 255         s->regs[index] = current_value;
 256         break;
 257     default:
 258         s->regs[index] = current_value;
 259         break;
 260     }
 261 }
 262
 263 static const struct MemoryRegionOps imx6_src_ops = {
 264     .read = imx6_src_read,
 265     .write = imx6_src_write,
 266     .endianness = DEVICE_NATIVE_ENDIAN,
 267     .valid = {
 268         /*
 269          * Our device would not work correctly if the guest was doing
 270          * unaligned access. This might not be a limitation on the real
 271          * device but in practice there is no reason for a guest to access
 272          * this device unaligned.
 273          */
 274         .min_access_size = 4,
 275         .max_access_size = 4,
 276         .unaligned = false,
 277     },
 278 };
 279
 280 static void imx6_src_realize(DeviceState *dev, Error **errp)
 281 {
 282     IMX6SRCState *s = IMX6_SRC(dev);
 283
 284     memory_region_init_io(&s->iomem, OBJECT(dev), &imx6_src_ops, s,
 285                           TYPE_IMX6_SRC, 0x1000);
 286     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
 287 }
 288
 289 static void imx6_src_class_init(ObjectClass *klass, void *data)
 290 {
 291     DeviceClass *dc = DEVICE_CLASS(klass);
 292
 293     dc->realize = imx6_src_realize;
 294     dc->reset = imx6_src_reset;
 295     dc->vmsd = &vmstate_imx6_src;
 296     dc->desc = "i.MX6 System Reset Controller";
 297 }
 298
 299 static const TypeInfo imx6_src_info = {
 300     .name          = TYPE_IMX6_SRC,
 301     .parent        = TYPE_SYS_BUS_DEVICE,
 302     .instance_size = sizeof(IMX6SRCState),
 303     .class_init    = imx6_src_class_init,
 304 };
 305
 306 static void imx6_src_register_types(void)
 307 {
 308     type_register_static(&imx6_src_info);
 309 }
 310
 311 type_init(imx6_src_register_types)