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 #include "migration/vmstate.h" 38 39 static const VMStateDescription vmstate_digic_timer = { 40 .name = "digic.timer", 41 .version_id = 1, 42 .minimum_version_id = 1, 43 .fields = (VMStateField[]) { 44 VMSTATE_PTIMER(ptimer, DigicTimerState), 45 VMSTATE_UINT32(control, DigicTimerState), 46 VMSTATE_UINT32(relvalue, DigicTimerState), 47 VMSTATE_END_OF_LIST() 48 } 49 }; 50 51 static void digic_timer_reset(DeviceState *dev) 52 { 53 DigicTimerState *s = DIGIC_TIMER(dev); 54 55 ptimer_stop(s->ptimer); 56 s->control = 0; 57 s->relvalue = 0; 58 } 59 60 static uint64_t digic_timer_read(void *opaque, hwaddr offset, unsigned size) 61 { 62 DigicTimerState *s = opaque; 63 uint64_t ret = 0; 64 65 switch (offset) { 66 case DIGIC_TIMER_CONTROL: 67 ret = s->control; 68 break; 69 case DIGIC_TIMER_RELVALUE: 70 ret = s->relvalue; 71 break; 72 case DIGIC_TIMER_VALUE: 73 ret = ptimer_get_count(s->ptimer) & 0xffff; 74 break; 75 default: 76 qemu_log_mask(LOG_UNIMP, 77 "digic-timer: read access to unknown register 0x" 78 TARGET_FMT_plx "\n", offset); 79 } 80 81 return ret; 82 } 83 84 static void digic_timer_write(void *opaque, hwaddr offset, 85 uint64_t value, unsigned size) 86 { 87 DigicTimerState *s = opaque; 88 89 switch (offset) { 90 case DIGIC_TIMER_CONTROL: 91 if (value & DIGIC_TIMER_CONTROL_RST) { 92 digic_timer_reset((DeviceState *)s); 93 break; 94 } 95 96 if (value & DIGIC_TIMER_CONTROL_EN) { 97 ptimer_run(s->ptimer, 0); 98 } 99 100 s->control = (uint32_t)value; 101 break; 102 103 case DIGIC_TIMER_RELVALUE: 104 s->relvalue = extract32(value, 0, 16); 105 ptimer_set_limit(s->ptimer, s->relvalue, 1); 106 break; 107 108 case DIGIC_TIMER_VALUE: 109 break; 110 111 default: 112 qemu_log_mask(LOG_UNIMP, 113 "digic-timer: read access to unknown register 0x" 114 TARGET_FMT_plx "\n", offset); 115 } 116 } 117 118 static const MemoryRegionOps digic_timer_ops = { 119 .read = digic_timer_read, 120 .write = digic_timer_write, 121 .impl = { 122 .min_access_size = 4, 123 .max_access_size = 4, 124 }, 125 .endianness = DEVICE_NATIVE_ENDIAN, 126 }; 127 128 static void digic_timer_init(Object *obj) 129 { 130 DigicTimerState *s = DIGIC_TIMER(obj); 131 132 s->ptimer = ptimer_init_with_bh(NULL, PTIMER_POLICY_DEFAULT); 133 134 /* 135 * FIXME: there is no documentation on Digic timer 136 * frequency setup so let it always run at 1 MHz 137 */ 138 ptimer_set_freq(s->ptimer, 1 * 1000 * 1000); 139 140 memory_region_init_io(&s->iomem, OBJECT(s), &digic_timer_ops, s, 141 TYPE_DIGIC_TIMER, 0x100); 142 sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->iomem); 143 } 144 145 static void digic_timer_class_init(ObjectClass *klass, void *class_data) 146 { 147 DeviceClass *dc = DEVICE_CLASS(klass); 148 149 dc->reset = digic_timer_reset; 150 dc->vmsd = &vmstate_digic_timer; 151 } 152 153 static const TypeInfo digic_timer_info = { 154 .name = TYPE_DIGIC_TIMER, 155 .parent = TYPE_SYS_BUS_DEVICE, 156 .instance_size = sizeof(DigicTimerState), 157 .instance_init = digic_timer_init, 158 .class_init = digic_timer_class_init, 159 }; 160 161 static void digic_timer_register_type(void) 162 { 163 type_register_static(&digic_timer_info); 164 } 165 166 type_init(digic_timer_register_type) 167