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/log.h" 18 #include "qemu/module.h" 19 #include "sysemu/runstate.h" 20 21 static uint64_t imx7_snvs_read(void *opaque, hwaddr offset, unsigned size) 22 { 23 return 0; 24 } 25 26 static void imx7_snvs_write(void *opaque, hwaddr offset, 27 uint64_t v, unsigned size) 28 { 29 const uint32_t value = v; 30 const uint32_t mask = SNVS_LPCR_TOP | SNVS_LPCR_DP_EN; 31 32 if (offset == SNVS_LPCR && ((value & mask) == mask)) { 33 qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN); 34 } 35 } 36 37 static const struct MemoryRegionOps imx7_snvs_ops = { 38 .read = imx7_snvs_read, 39 .write = imx7_snvs_write, 40 .endianness = DEVICE_NATIVE_ENDIAN, 41 .impl = { 42 /* 43 * Our device would not work correctly if the guest was doing 44 * unaligned access. This might not be a limitation on the real 45 * device but in practice there is no reason for a guest to access 46 * this device unaligned. 47 */ 48 .min_access_size = 4, 49 .max_access_size = 4, 50 .unaligned = false, 51 }, 52 }; 53 54 static void imx7_snvs_init(Object *obj) 55 { 56 SysBusDevice *sd = SYS_BUS_DEVICE(obj); 57 IMX7SNVSState *s = IMX7_SNVS(obj); 58 59 memory_region_init_io(&s->mmio, obj, &imx7_snvs_ops, s, 60 TYPE_IMX7_SNVS, 0x1000); 61 62 sysbus_init_mmio(sd, &s->mmio); 63 } 64 65 static void imx7_snvs_class_init(ObjectClass *klass, void *data) 66 { 67 DeviceClass *dc = DEVICE_CLASS(klass); 68 69 dc->desc = "i.MX7 Secure Non-Volatile Storage Module"; 70 } 71 72 static const TypeInfo imx7_snvs_info = { 73 .name = TYPE_IMX7_SNVS, 74 .parent = TYPE_SYS_BUS_DEVICE, 75 .instance_size = sizeof(IMX7SNVSState), 76 .instance_init = imx7_snvs_init, 77 .class_init = imx7_snvs_class_init, 78 }; 79 80 static void imx7_snvs_register_type(void) 81 { 82 type_register_static(&imx7_snvs_info); 83 } 84 type_init(imx7_snvs_register_type) 85