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