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 #include "qemu/module.h" 34 #include "qemu/log.h" 35 36 #include "hw/timer/digic-timer.h" 37 38 static const VMStateDescription vmstate_digic_timer = { 39 .name = "digic.timer", 40 .version_id = 1, 41 .minimum_version_id = 1, 42 .fields = (VMStateField[]) { 43 VMSTATE_PTIMER(ptimer, DigicTimerState), 44 VMSTATE_UINT32(control, DigicTimerState), 45 VMSTATE_UINT32(relvalue, DigicTimerState), 46 VMSTATE_END_OF_LIST() 47 } 48 }; 49 50 static void digic_timer_reset(DeviceState *dev) 51 { 52 DigicTimerState *s = DIGIC_TIMER(dev); 53 54 ptimer_stop(s->ptimer); 55 s->control = 0; 56 s->relvalue = 0; 57 } 58 59 static uint64_t digic_timer_read(void *opaque, hwaddr offset, unsigned size) 60 { 61 DigicTimerState *s = opaque; 62 uint64_t ret = 0; 63 64 switch (offset) { 65 case DIGIC_TIMER_CONTROL: 66 ret = s->control; 67 break; 68 case DIGIC_TIMER_RELVALUE: 69 ret = s->relvalue; 70 break; 71 case DIGIC_TIMER_VALUE: 72 ret = ptimer_get_count(s->ptimer) & 0xffff; 73 break; 74 default: 75 qemu_log_mask(LOG_UNIMP, 76 "digic-timer: read access to unknown register 0x" 77 TARGET_FMT_plx "\n", offset); 78 } 79 80 return ret; 81 } 82 83 static void digic_timer_write(void *opaque, hwaddr offset, 84 uint64_t value, unsigned size) 85 { 86 DigicTimerState *s = opaque; 87 88 switch (offset) { 89 case DIGIC_TIMER_CONTROL: 90 if (value & DIGIC_TIMER_CONTROL_RST) { 91 digic_timer_reset((DeviceState *)s); 92 break; 93 } 94 95 if (value & DIGIC_TIMER_CONTROL_EN) { 96 ptimer_run(s->ptimer, 0); 97 } 98 99 s->control = (uint32_t)value; 100 break; 101 102 case DIGIC_TIMER_RELVALUE: 103 s->relvalue = extract32(value, 0, 16); 104 ptimer_set_limit(s->ptimer, s->relvalue, 1); 105 break; 106 107 case DIGIC_TIMER_VALUE: 108 break; 109 110 default: 111 qemu_log_mask(LOG_UNIMP, 112 "digic-timer: read access to unknown register 0x" 113 TARGET_FMT_plx "\n", offset); 114 } 115 } 116 117 static const MemoryRegionOps digic_timer_ops = { 118 .read = digic_timer_read, 119 .write = digic_timer_write, 120 .impl = { 121 .min_access_size = 4, 122 .max_access_size = 4, 123 }, 124 .endianness = DEVICE_NATIVE_ENDIAN, 125 }; 126 127 static void digic_timer_init(Object *obj) 128 { 129 DigicTimerState *s = DIGIC_TIMER(obj); 130 131 s->ptimer = ptimer_init(NULL, PTIMER_POLICY_DEFAULT); 132 133 /* 134 * FIXME: there is no documentation on Digic timer 135 * frequency setup so let it always run at 1 MHz 136 */ 137 ptimer_set_freq(s->ptimer, 1 * 1000 * 1000); 138 139 memory_region_init_io(&s->iomem, OBJECT(s), &digic_timer_ops, s, 140 TYPE_DIGIC_TIMER, 0x100); 141 sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->iomem); 142 } 143 144 static void digic_timer_class_init(ObjectClass *klass, void *class_data) 145 { 146 DeviceClass *dc = DEVICE_CLASS(klass); 147 148 dc->reset = digic_timer_reset; 149 dc->vmsd = &vmstate_digic_timer; 150 } 151 152 static const TypeInfo digic_timer_info = { 153 .name = TYPE_DIGIC_TIMER, 154 .parent = TYPE_SYS_BUS_DEVICE, 155 .instance_size = sizeof(DigicTimerState), 156 .instance_init = digic_timer_init, 157 .class_init = digic_timer_class_init, 158 }; 159 160 static void digic_timer_register_type(void) 161 { 162 type_register_static(&digic_timer_info); 163 } 164 165 type_init(digic_timer_register_type) 166