hw/misc/imx7_src.c

   1 /*
   2  * IMX7 System Reset Controller
   3  *
   4  * Copyright (c) 2023 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/imx7_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 "target/arm/arm-powerctl.h"
  19 #include "hw/core/cpu.h"
  20 #include "hw/registerfields.h"
  21
  22 #include "trace.h"
  23
  24 static const char *imx7_src_reg_name(uint32_t reg)
  25 {
  26     static char unknown[20];
  27
  28     switch (reg) {
  29     case SRC_SCR:
  30         return "SRC_SCR";
  31     case SRC_A7RCR0:
  32         return "SRC_A7RCR0";
  33     case SRC_A7RCR1:
  34         return "SRC_A7RCR1";
  35     case SRC_M4RCR:
  36         return "SRC_M4RCR";
  37     case SRC_ERCR:
  38         return "SRC_ERCR";
  39     case SRC_HSICPHY_RCR:
  40         return "SRC_HSICPHY_RCR";
  41     case SRC_USBOPHY1_RCR:
  42         return "SRC_USBOPHY1_RCR";
  43     case SRC_USBOPHY2_RCR:
  44         return "SRC_USBOPHY2_RCR";
  45     case SRC_PCIEPHY_RCR:
  46         return "SRC_PCIEPHY_RCR";
  47     case SRC_SBMR1:
  48         return "SRC_SBMR1";
  49     case SRC_SRSR:
  50         return "SRC_SRSR";
  51     case SRC_SISR:
  52         return "SRC_SISR";
  53     case SRC_SIMR:
  54         return "SRC_SIMR";
  55     case SRC_SBMR2:
  56         return "SRC_SBMR2";
  57     case SRC_GPR1:
  58         return "SRC_GPR1";
  59     case SRC_GPR2:
  60         return "SRC_GPR2";
  61     case SRC_GPR3:
  62         return "SRC_GPR3";
  63     case SRC_GPR4:
  64         return "SRC_GPR4";
  65     case SRC_GPR5:
  66         return "SRC_GPR5";
  67     case SRC_GPR6:
  68         return "SRC_GPR6";
  69     case SRC_GPR7:
  70         return "SRC_GPR7";
  71     case SRC_GPR8:
  72         return "SRC_GPR8";
  73     case SRC_GPR9:
  74         return "SRC_GPR9";
  75     case SRC_GPR10:
  76         return "SRC_GPR10";
  77     default:
  78         sprintf(unknown, "%u ?", reg);
  79         return unknown;
  80     }
  81 }
  82
  83 static const VMStateDescription vmstate_imx7_src = {
  84     .name = TYPE_IMX7_SRC,
  85     .version_id = 1,
  86     .minimum_version_id = 1,
  87     .fields = (VMStateField[]) {
  88         VMSTATE_UINT32_ARRAY(regs, IMX7SRCState, SRC_MAX),
  89         VMSTATE_END_OF_LIST()
  90     },
  91 };
  92
  93 static void imx7_src_reset(DeviceState *dev)
  94 {
  95     IMX7SRCState *s = IMX7_SRC(dev);
  96
  97     memset(s->regs, 0, sizeof(s->regs));
  98
  99     /* Set reset values */
 100     s->regs[SRC_SCR] = 0xA0;
 101     s->regs[SRC_SRSR] = 0x1;
 102     s->regs[SRC_SIMR] = 0x1F;
 103 }
 104
 105 static uint64_t imx7_src_read(void *opaque, hwaddr offset, unsigned size)
 106 {
 107     uint32_t value = 0;
 108     IMX7SRCState *s = (IMX7SRCState *)opaque;
 109     uint32_t index = offset >> 2;
 110
 111     if (index < SRC_MAX) {
 112         value = s->regs[index];
 113     } else {
 114         qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
 115                       HWADDR_PRIx "\n", TYPE_IMX7_SRC, __func__, offset);
 116     }
 117
 118     trace_imx7_src_read(imx7_src_reg_name(index), value);
 119
 120     return value;
 121 }
 122
 123
 124 /*
 125  * The reset is asynchronous so we need to defer clearing the reset
 126  * bit until the work is completed.
 127  */
 128
 129 struct SRCSCRResetInfo {
 130     IMX7SRCState *s;
 131     uint32_t reset_bit;
 132 };
 133
 134 static void imx7_clear_reset_bit(CPUState *cpu, run_on_cpu_data data)
 135 {
 136     struct SRCSCRResetInfo *ri = data.host_ptr;
 137     IMX7SRCState *s = ri->s;
 138
 139     assert(qemu_mutex_iothread_locked());
 140
 141     s->regs[SRC_A7RCR0] = deposit32(s->regs[SRC_A7RCR0], ri->reset_bit, 1, 0);
 142
 143     trace_imx7_src_write(imx7_src_reg_name(SRC_A7RCR0), s->regs[SRC_A7RCR0]);
 144
 145     g_free(ri);
 146 }
 147
 148 static void imx7_defer_clear_reset_bit(uint32_t cpuid,
 149                                        IMX7SRCState *s,
 150                                        uint32_t reset_shift)
 151 {
 152     struct SRCSCRResetInfo *ri;
 153     CPUState *cpu = arm_get_cpu_by_id(cpuid);
 154
 155     if (!cpu) {
 156         return;
 157     }
 158
 159     ri = g_new(struct SRCSCRResetInfo, 1);
 160     ri->s = s;
 161     ri->reset_bit = reset_shift;
 162
 163     async_run_on_cpu(cpu, imx7_clear_reset_bit, RUN_ON_CPU_HOST_PTR(ri));
 164 }
 165
 166
 167 static void imx7_src_write(void *opaque, hwaddr offset, uint64_t value,
 168                            unsigned size)
 169 {
 170     IMX7SRCState *s = (IMX7SRCState *)opaque;
 171     uint32_t index = offset >> 2;
 172     long unsigned int change_mask;
 173     uint32_t current_value = value;
 174
 175     if (index >= SRC_MAX) {
 176         qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
 177                       HWADDR_PRIx "\n", TYPE_IMX7_SRC, __func__, offset);
 178         return;
 179     }
 180
 181     trace_imx7_src_write(imx7_src_reg_name(SRC_A7RCR0), s->regs[SRC_A7RCR0]);
 182
 183     change_mask = s->regs[index] ^ (uint32_t)current_value;
 184
 185     switch (index) {
 186     case SRC_A7RCR0:
 187         if (FIELD_EX32(change_mask, CORE0, RST)) {
 188             arm_reset_cpu(0);
 189             imx7_defer_clear_reset_bit(0, s, R_CORE0_RST_SHIFT);
 190         }
 191         if (FIELD_EX32(change_mask, CORE1, RST)) {
 192             arm_reset_cpu(1);
 193             imx7_defer_clear_reset_bit(1, s, R_CORE1_RST_SHIFT);
 194         }
 195         s->regs[index] = current_value;
 196         break;
 197     case SRC_A7RCR1:
 198         /*
 199          * On real hardware when the system reset controller starts a
 200          * secondary CPU it runs through some boot ROM code which reads
 201          * the SRC_GPRX registers controlling the start address and branches
 202          * to it.
 203          * Here we are taking a short cut and branching directly to the
 204          * requested address (we don't want to run the boot ROM code inside
 205          * QEMU)
 206          */
 207         if (FIELD_EX32(change_mask, CORE1, ENABLE)) {
 208             if (FIELD_EX32(current_value, CORE1, ENABLE)) {
 209                 /* CORE 1 is brought up */
 210                 arm_set_cpu_on(1, s->regs[SRC_GPR3], s->regs[SRC_GPR4],
 211                                3, false);
 212             } else {
 213                 /* CORE 1 is shut down */
 214                 arm_set_cpu_off(1);
 215             }
 216             /* We clear the reset bits as the processor changed state */
 217             imx7_defer_clear_reset_bit(1, s, R_CORE1_RST_SHIFT);
 218             clear_bit(R_CORE1_RST_SHIFT, &change_mask);
 219         }
 220         s->regs[index] = current_value;
 221         break;
 222     default:
 223         s->regs[index] = current_value;
 224         break;
 225     }
 226 }
 227
 228 static const struct MemoryRegionOps imx7_src_ops = {
 229     .read = imx7_src_read,
 230     .write = imx7_src_write,
 231     .endianness = DEVICE_NATIVE_ENDIAN,
 232     .valid = {
 233         /*
 234          * Our device would not work correctly if the guest was doing
 235          * unaligned access. This might not be a limitation on the real
 236          * device but in practice there is no reason for a guest to access
 237          * this device unaligned.
 238          */
 239         .min_access_size = 4,
 240         .max_access_size = 4,
 241         .unaligned = false,
 242     },
 243 };
 244
 245 static void imx7_src_realize(DeviceState *dev, Error **errp)
 246 {
 247     IMX7SRCState *s = IMX7_SRC(dev);
 248
 249     memory_region_init_io(&s->iomem, OBJECT(dev), &imx7_src_ops, s,
 250                           TYPE_IMX7_SRC, 0x1000);
 251     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
 252 }
 253
 254 static void imx7_src_class_init(ObjectClass *klass, void *data)
 255 {
 256     DeviceClass *dc = DEVICE_CLASS(klass);
 257
 258     dc->realize = imx7_src_realize;
 259     dc->reset = imx7_src_reset;
 260     dc->vmsd = &vmstate_imx7_src;
 261     dc->desc = "i.MX6 System Reset Controller";
 262 }
 263
 264 static const TypeInfo imx7_src_info = {
 265     .name          = TYPE_IMX7_SRC,
 266     .parent        = TYPE_SYS_BUS_DEVICE,
 267     .instance_size = sizeof(IMX7SRCState),
 268     .class_init    = imx7_src_class_init,
 269 };
 270
 271 static void imx7_src_register_types(void)
 272 {
 273     type_register_static(&imx7_src_info);
 274 }
 275
 276 type_init(imx7_src_register_types)