1 /* 2 * IMX7 Secure Non-Volatile Storage 3 * 4 * Copyright (c) 2018, Impinj, Inc. 5 * 6 * Author: Andrey Smirnov <andrew.smirnov@gmail.com> 7 * 8 * This work is licensed under the terms of the GNU GPL, version 2 or later. 9 * See the COPYING file in the top-level directory. 10 * 11 * Bare minimum emulation code needed to support being able to shut 12 * down linux guest gracefully. 13 */ 14 15 #include "qemu/osdep.h" 16 #include "hw/misc/imx7_snvs.h" 17 #include "qemu/module.h" 18 #include "sysemu/runstate.h" 19 #include "trace.h" 20 21 static uint64_t imx7_snvs_read(void *opaque, hwaddr offset, unsigned size) 22 { 23 trace_imx7_snvs_read(offset, 0); 24 25 return 0; 26 } 27 28 static void imx7_snvs_write(void *opaque, hwaddr offset, 29 uint64_t v, unsigned size) 30 { 31 const uint32_t value = v; 32 const uint32_t mask = SNVS_LPCR_TOP | SNVS_LPCR_DP_EN; 33 34 trace_imx7_snvs_write(offset, value); 35 36 if (offset == SNVS_LPCR && ((value & mask) == mask)) { 37 qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN); 38 } 39 } 40 41 static const struct MemoryRegionOps imx7_snvs_ops = { 42 .read = imx7_snvs_read, 43 .write = imx7_snvs_write, 44 .endianness = DEVICE_NATIVE_ENDIAN, 45 .impl = { 46 /* 47 * Our device would not work correctly if the guest was doing 48 * unaligned access. This might not be a limitation on the real 49 * device but in practice there is no reason for a guest to access 50 * this device unaligned. 51 */ 52 .min_access_size = 4, 53 .max_access_size = 4, 54 .unaligned = false, 55 }, 56 }; 57 58 static void imx7_snvs_init(Object *obj) 59 { 60 SysBusDevice *sd = SYS_BUS_DEVICE(obj); 61 IMX7SNVSState *s = IMX7_SNVS(obj); 62 63 memory_region_init_io(&s->mmio, obj, &imx7_snvs_ops, s, 64 TYPE_IMX7_SNVS, 0x1000); 65 66 sysbus_init_mmio(sd, &s->mmio); 67 } 68 69 static void imx7_snvs_class_init(ObjectClass *klass, void *data) 70 { 71 DeviceClass *dc = DEVICE_CLASS(klass); 72 73 dc->desc = "i.MX7 Secure Non-Volatile Storage Module"; 74 } 75 76 static const TypeInfo imx7_snvs_info = { 77 .name = TYPE_IMX7_SNVS, 78 .parent = TYPE_SYS_BUS_DEVICE, 79 .instance_size = sizeof(IMX7SNVSState), 80 .instance_init = imx7_snvs_init, 81 .class_init = imx7_snvs_class_init, 82 }; 83 84 static void imx7_snvs_register_type(void) 85 { 86 type_register_static(&imx7_snvs_info); 87 } 88 type_init(imx7_snvs_register_type) 89