1 /* 2 * QEMU model of the Canon DIGIC timer block. 3 * 4 * Copyright (C) 2013 Antony Pavlov <antonynpavlov@gmail.com> 5 * 6 * This model is based on reverse engineering efforts 7 * made by CHDK (http://chdk.wikia.com) and 8 * Magic Lantern (http://www.magiclantern.fm) projects 9 * contributors. 10 * 11 * See "Timer/Clock Module" docs here: 12 * http://magiclantern.wikia.com/wiki/Register_Map 13 * 14 * The QEMU model of the OSTimer in PKUnity SoC by Guan Xuetao 15 * is used as a template. 16 * 17 * This program is free software; you can redistribute it and/or modify 18 * it under the terms of the GNU General Public License as published by 19 * the Free Software Foundation; either version 2 of the License, or 20 * (at your option) any later version. 21 * 22 * This program is distributed in the hope that it will be useful, 23 * but WITHOUT ANY WARRANTY; without even the implied warranty of 24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 25 * GNU General Public License for more details. 26 * 27 */ 28 29 #include "qemu/osdep.h" 30 #include "hw/sysbus.h" 31 #include "hw/ptimer.h" 32 #include "qemu/main-loop.h" 33 34 #include "hw/timer/digic-timer.h" 35 36 static const VMStateDescription vmstate_digic_timer = { 37 .name = "digic.timer", 38 .version_id = 1, 39 .minimum_version_id = 1, 40 .fields = (VMStateField[]) { 41 VMSTATE_PTIMER(ptimer, DigicTimerState), 42 VMSTATE_UINT32(control, DigicTimerState), 43 VMSTATE_UINT32(relvalue, DigicTimerState), 44 VMSTATE_END_OF_LIST() 45 } 46 }; 47 48 static void digic_timer_reset(DeviceState *dev) 49 { 50 DigicTimerState *s = DIGIC_TIMER(dev); 51 52 ptimer_stop(s->ptimer); 53 s->control = 0; 54 s->relvalue = 0; 55 } 56 57 static uint64_t digic_timer_read(void *opaque, hwaddr offset, unsigned size) 58 { 59 DigicTimerState *s = opaque; 60 uint64_t ret = 0; 61 62 switch (offset) { 63 case DIGIC_TIMER_CONTROL: 64 ret = s->control; 65 break; 66 case DIGIC_TIMER_RELVALUE: 67 ret = s->relvalue; 68 break; 69 case DIGIC_TIMER_VALUE: 70 ret = ptimer_get_count(s->ptimer) & 0xffff; 71 break; 72 default: 73 qemu_log_mask(LOG_UNIMP, 74 "digic-timer: read access to unknown register 0x" 75 TARGET_FMT_plx, offset); 76 } 77 78 return ret; 79 } 80 81 static void digic_timer_write(void *opaque, hwaddr offset, 82 uint64_t value, unsigned size) 83 { 84 DigicTimerState *s = opaque; 85 86 switch (offset) { 87 case DIGIC_TIMER_CONTROL: 88 if (value & DIGIC_TIMER_CONTROL_RST) { 89 digic_timer_reset((DeviceState *)s); 90 break; 91 } 92 93 if (value & DIGIC_TIMER_CONTROL_EN) { 94 ptimer_run(s->ptimer, 0); 95 } 96 97 s->control = (uint32_t)value; 98 break; 99 100 case DIGIC_TIMER_RELVALUE: 101 s->relvalue = extract32(value, 0, 16); 102 ptimer_set_limit(s->ptimer, s->relvalue, 1); 103 break; 104 105 case DIGIC_TIMER_VALUE: 106 break; 107 108 default: 109 qemu_log_mask(LOG_UNIMP, 110 "digic-timer: read access to unknown register 0x" 111 TARGET_FMT_plx, offset); 112 } 113 } 114 115 static const MemoryRegionOps digic_timer_ops = { 116 .read = digic_timer_read, 117 .write = digic_timer_write, 118 .impl = { 119 .min_access_size = 4, 120 .max_access_size = 4, 121 }, 122 .endianness = DEVICE_NATIVE_ENDIAN, 123 }; 124 125 static void digic_timer_init(Object *obj) 126 { 127 DigicTimerState *s = DIGIC_TIMER(obj); 128 129 s->ptimer = ptimer_init(NULL); 130 131 /* 132 * FIXME: there is no documentation on Digic timer 133 * frequency setup so let it always run at 1 MHz 134 */ 135 ptimer_set_freq(s->ptimer, 1 * 1000 * 1000); 136 137 memory_region_init_io(&s->iomem, OBJECT(s), &digic_timer_ops, s, 138 TYPE_DIGIC_TIMER, 0x100); 139 sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->iomem); 140 } 141 142 static void digic_timer_class_init(ObjectClass *klass, void *class_data) 143 { 144 DeviceClass *dc = DEVICE_CLASS(klass); 145 146 dc->reset = digic_timer_reset; 147 dc->vmsd = &vmstate_digic_timer; 148 } 149 150 static const TypeInfo digic_timer_info = { 151 .name = TYPE_DIGIC_TIMER, 152 .parent = TYPE_SYS_BUS_DEVICE, 153 .instance_size = sizeof(DigicTimerState), 154 .instance_init = digic_timer_init, 155 .class_init = digic_timer_class_init, 156 }; 157 158 static void digic_timer_register_type(void) 159 { 160 type_register_static(&digic_timer_info); 161 } 162 163 type_init(digic_timer_register_type) 164