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/module.h" 33 #include "qemu/log.h" 34 35 #include "hw/timer/digic-timer.h" 36 #include "migration/vmstate.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_transaction_begin(s->ptimer); 55 ptimer_stop(s->ptimer); 56 ptimer_transaction_commit(s->ptimer); 57 s->control = 0; 58 s->relvalue = 0; 59 } 60 61 static uint64_t digic_timer_read(void *opaque, hwaddr offset, unsigned size) 62 { 63 DigicTimerState *s = opaque; 64 uint64_t ret = 0; 65 66 switch (offset) { 67 case DIGIC_TIMER_CONTROL: 68 ret = s->control; 69 break; 70 case DIGIC_TIMER_RELVALUE: 71 ret = s->relvalue; 72 break; 73 case DIGIC_TIMER_VALUE: 74 ret = ptimer_get_count(s->ptimer) & 0xffff; 75 break; 76 default: 77 qemu_log_mask(LOG_UNIMP, 78 "digic-timer: read access to unknown register 0x" 79 HWADDR_FMT_plx "\n", offset); 80 } 81 82 return ret; 83 } 84 85 static void digic_timer_write(void *opaque, hwaddr offset, 86 uint64_t value, unsigned size) 87 { 88 DigicTimerState *s = opaque; 89 90 switch (offset) { 91 case DIGIC_TIMER_CONTROL: 92 if (value & DIGIC_TIMER_CONTROL_RST) { 93 digic_timer_reset((DeviceState *)s); 94 break; 95 } 96 97 ptimer_transaction_begin(s->ptimer); 98 if (value & DIGIC_TIMER_CONTROL_EN) { 99 ptimer_run(s->ptimer, 0); 100 } 101 102 s->control = (uint32_t)value; 103 ptimer_transaction_commit(s->ptimer); 104 break; 105 106 case DIGIC_TIMER_RELVALUE: 107 s->relvalue = extract32(value, 0, 16); 108 ptimer_transaction_begin(s->ptimer); 109 ptimer_set_limit(s->ptimer, s->relvalue, 1); 110 ptimer_transaction_commit(s->ptimer); 111 break; 112 113 case DIGIC_TIMER_VALUE: 114 break; 115 116 default: 117 qemu_log_mask(LOG_UNIMP, 118 "digic-timer: read access to unknown register 0x" 119 HWADDR_FMT_plx "\n", offset); 120 } 121 } 122 123 static const MemoryRegionOps digic_timer_ops = { 124 .read = digic_timer_read, 125 .write = digic_timer_write, 126 .impl = { 127 .min_access_size = 4, 128 .max_access_size = 4, 129 }, 130 .endianness = DEVICE_NATIVE_ENDIAN, 131 }; 132 133 static void digic_timer_tick(void *opaque) 134 { 135 /* Nothing to do on timer rollover */ 136 } 137 138 static void digic_timer_init(Object *obj) 139 { 140 DigicTimerState *s = DIGIC_TIMER(obj); 141 142 s->ptimer = ptimer_init(digic_timer_tick, NULL, PTIMER_POLICY_LEGACY); 143 144 /* 145 * FIXME: there is no documentation on Digic timer 146 * frequency setup so let it always run at 1 MHz 147 */ 148 ptimer_transaction_begin(s->ptimer); 149 ptimer_set_freq(s->ptimer, 1 * 1000 * 1000); 150 ptimer_transaction_commit(s->ptimer); 151 152 memory_region_init_io(&s->iomem, OBJECT(s), &digic_timer_ops, s, 153 TYPE_DIGIC_TIMER, 0x100); 154 sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->iomem); 155 } 156 157 static void digic_timer_finalize(Object *obj) 158 { 159 DigicTimerState *s = DIGIC_TIMER(obj); 160 161 ptimer_free(s->ptimer); 162 } 163 164 static void digic_timer_class_init(ObjectClass *klass, void *class_data) 165 { 166 DeviceClass *dc = DEVICE_CLASS(klass); 167 168 dc->reset = digic_timer_reset; 169 dc->vmsd = &vmstate_digic_timer; 170 } 171 172 static const TypeInfo digic_timer_info = { 173 .name = TYPE_DIGIC_TIMER, 174 .parent = TYPE_SYS_BUS_DEVICE, 175 .instance_size = sizeof(DigicTimerState), 176 .instance_init = digic_timer_init, 177 .instance_finalize = digic_timer_finalize, 178 .class_init = digic_timer_class_init, 179 }; 180 181 static void digic_timer_register_type(void) 182 { 183 type_register_static(&digic_timer_info); 184 } 185 186 type_init(digic_timer_register_type) 187