1 /* 2 * QEMU ETRAX System Emulator 3 * 4 * Copyright (c) 2007 Edgar E. Iglesias, Axis Communications AB. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 25 #include "qemu/osdep.h" 26 #include "hw/irq.h" 27 #include "hw/qdev-properties.h" 28 #include "hw/qdev-properties-system.h" 29 #include "hw/sysbus.h" 30 #include "chardev/char-fe.h" 31 #include "qemu/log.h" 32 #include "qemu/module.h" 33 #include "qom/object.h" 34 35 #define D(x) 36 37 #define RW_TR_CTRL (0x00 / 4) 38 #define RW_TR_DMA_EN (0x04 / 4) 39 #define RW_REC_CTRL (0x08 / 4) 40 #define RW_DOUT (0x1c / 4) 41 #define RS_STAT_DIN (0x20 / 4) 42 #define R_STAT_DIN (0x24 / 4) 43 #define RW_INTR_MASK (0x2c / 4) 44 #define RW_ACK_INTR (0x30 / 4) 45 #define R_INTR (0x34 / 4) 46 #define R_MASKED_INTR (0x38 / 4) 47 #define R_MAX (0x3c / 4) 48 49 #define STAT_DAV 16 50 #define STAT_TR_IDLE 22 51 #define STAT_TR_RDY 24 52 53 #define TYPE_ETRAX_FS_SERIAL "etraxfs-serial" 54 typedef struct ETRAXSerial ETRAXSerial; 55 DECLARE_INSTANCE_CHECKER(ETRAXSerial, ETRAX_SERIAL, 56 TYPE_ETRAX_FS_SERIAL) 57 58 struct ETRAXSerial { 59 SysBusDevice parent_obj; 60 61 MemoryRegion mmio; 62 CharBackend chr; 63 qemu_irq irq; 64 65 int pending_tx; 66 67 uint8_t rx_fifo[16]; 68 unsigned int rx_fifo_pos; 69 unsigned int rx_fifo_len; 70 71 /* Control registers. */ 72 uint32_t regs[R_MAX]; 73 }; 74 75 static void ser_update_irq(ETRAXSerial *s) 76 { 77 78 if (s->rx_fifo_len) { 79 s->regs[R_INTR] |= 8; 80 } else { 81 s->regs[R_INTR] &= ~8; 82 } 83 84 s->regs[R_MASKED_INTR] = s->regs[R_INTR] & s->regs[RW_INTR_MASK]; 85 qemu_set_irq(s->irq, !!s->regs[R_MASKED_INTR]); 86 } 87 88 static uint64_t 89 ser_read(void *opaque, hwaddr addr, unsigned int size) 90 { 91 ETRAXSerial *s = opaque; 92 uint32_t r = 0; 93 94 addr >>= 2; 95 switch (addr) 96 { 97 case R_STAT_DIN: 98 r = s->rx_fifo[(s->rx_fifo_pos - s->rx_fifo_len) & 15]; 99 if (s->rx_fifo_len) { 100 r |= 1 << STAT_DAV; 101 } 102 r |= 1 << STAT_TR_RDY; 103 r |= 1 << STAT_TR_IDLE; 104 break; 105 case RS_STAT_DIN: 106 r = s->rx_fifo[(s->rx_fifo_pos - s->rx_fifo_len) & 15]; 107 if (s->rx_fifo_len) { 108 r |= 1 << STAT_DAV; 109 s->rx_fifo_len--; 110 } 111 r |= 1 << STAT_TR_RDY; 112 r |= 1 << STAT_TR_IDLE; 113 break; 114 default: 115 r = s->regs[addr]; 116 D(qemu_log("%s " HWADDR_FMT_plx "=%x\n", __func__, addr, r)); 117 break; 118 } 119 return r; 120 } 121 122 static void 123 ser_write(void *opaque, hwaddr addr, 124 uint64_t val64, unsigned int size) 125 { 126 ETRAXSerial *s = opaque; 127 uint32_t value = val64; 128 unsigned char ch = val64; 129 130 D(qemu_log("%s " HWADDR_FMT_plx "=%x\n", __func__, addr, value)); 131 addr >>= 2; 132 switch (addr) 133 { 134 case RW_DOUT: 135 /* XXX this blocks entire thread. Rewrite to use 136 * qemu_chr_fe_write and background I/O callbacks */ 137 qemu_chr_fe_write_all(&s->chr, &ch, 1); 138 s->regs[R_INTR] |= 3; 139 s->pending_tx = 1; 140 s->regs[addr] = value; 141 break; 142 case RW_ACK_INTR: 143 if (s->pending_tx) { 144 value &= ~1; 145 s->pending_tx = 0; 146 D(qemu_log("fixedup value=%x r_intr=%x\n", 147 value, s->regs[R_INTR])); 148 } 149 s->regs[addr] = value; 150 s->regs[R_INTR] &= ~value; 151 D(printf("r_intr=%x\n", s->regs[R_INTR])); 152 break; 153 default: 154 s->regs[addr] = value; 155 break; 156 } 157 ser_update_irq(s); 158 } 159 160 static const MemoryRegionOps ser_ops = { 161 .read = ser_read, 162 .write = ser_write, 163 .endianness = DEVICE_NATIVE_ENDIAN, 164 .valid = { 165 .min_access_size = 4, 166 .max_access_size = 4 167 } 168 }; 169 170 static Property etraxfs_ser_properties[] = { 171 DEFINE_PROP_CHR("chardev", ETRAXSerial, chr), 172 DEFINE_PROP_END_OF_LIST(), 173 }; 174 175 static void serial_receive(void *opaque, const uint8_t *buf, int size) 176 { 177 ETRAXSerial *s = opaque; 178 int i; 179 180 /* Got a byte. */ 181 if (s->rx_fifo_len >= 16) { 182 D(qemu_log("WARNING: UART dropped char.\n")); 183 return; 184 } 185 186 for (i = 0; i < size; i++) { 187 s->rx_fifo[s->rx_fifo_pos] = buf[i]; 188 s->rx_fifo_pos++; 189 s->rx_fifo_pos &= 15; 190 s->rx_fifo_len++; 191 } 192 193 ser_update_irq(s); 194 } 195 196 static int serial_can_receive(void *opaque) 197 { 198 ETRAXSerial *s = opaque; 199 200 /* Is the receiver enabled? */ 201 if (!(s->regs[RW_REC_CTRL] & (1 << 3))) { 202 return 0; 203 } 204 205 return sizeof(s->rx_fifo) - s->rx_fifo_len; 206 } 207 208 static void serial_event(void *opaque, QEMUChrEvent event) 209 { 210 211 } 212 213 static void etraxfs_ser_reset(DeviceState *d) 214 { 215 ETRAXSerial *s = ETRAX_SERIAL(d); 216 217 /* transmitter begins ready and idle. */ 218 s->regs[RS_STAT_DIN] |= (1 << STAT_TR_RDY); 219 s->regs[RS_STAT_DIN] |= (1 << STAT_TR_IDLE); 220 221 s->regs[RW_REC_CTRL] = 0x10000; 222 223 } 224 225 static void etraxfs_ser_init(Object *obj) 226 { 227 ETRAXSerial *s = ETRAX_SERIAL(obj); 228 SysBusDevice *dev = SYS_BUS_DEVICE(obj); 229 230 sysbus_init_irq(dev, &s->irq); 231 memory_region_init_io(&s->mmio, obj, &ser_ops, s, 232 "etraxfs-serial", R_MAX * 4); 233 sysbus_init_mmio(dev, &s->mmio); 234 } 235 236 static void etraxfs_ser_realize(DeviceState *dev, Error **errp) 237 { 238 ETRAXSerial *s = ETRAX_SERIAL(dev); 239 240 qemu_chr_fe_set_handlers(&s->chr, 241 serial_can_receive, serial_receive, 242 serial_event, NULL, s, NULL, true); 243 } 244 245 static void etraxfs_ser_class_init(ObjectClass *klass, void *data) 246 { 247 DeviceClass *dc = DEVICE_CLASS(klass); 248 249 dc->reset = etraxfs_ser_reset; 250 device_class_set_props(dc, etraxfs_ser_properties); 251 dc->realize = etraxfs_ser_realize; 252 } 253 254 static const TypeInfo etraxfs_ser_info = { 255 .name = TYPE_ETRAX_FS_SERIAL, 256 .parent = TYPE_SYS_BUS_DEVICE, 257 .instance_size = sizeof(ETRAXSerial), 258 .instance_init = etraxfs_ser_init, 259 .class_init = etraxfs_ser_class_init, 260 }; 261 262 static void etraxfs_serial_register_types(void) 263 { 264 type_register_static(&etraxfs_ser_info); 265 } 266 267 type_init(etraxfs_serial_register_types) 268