pl022.c (9001B)
1/* 2 * Arm PrimeCell PL022 Synchronous Serial Port 3 * 4 * Copyright (c) 2007 CodeSourcery. 5 * Written by Paul Brook 6 * 7 * This code is licensed under the GPL. 8 */ 9 10#include "qemu/osdep.h" 11#include "hw/sysbus.h" 12#include "migration/vmstate.h" 13#include "hw/irq.h" 14#include "hw/ssi/pl022.h" 15#include "hw/ssi/ssi.h" 16#include "qemu/log.h" 17#include "qemu/module.h" 18 19//#define DEBUG_PL022 1 20 21#ifdef DEBUG_PL022 22#define DPRINTF(fmt, ...) \ 23do { printf("pl022: " fmt , ## __VA_ARGS__); } while (0) 24#define BADF(fmt, ...) \ 25do { fprintf(stderr, "pl022: error: " fmt , ## __VA_ARGS__); exit(1);} while (0) 26#else 27#define DPRINTF(fmt, ...) do {} while(0) 28#define BADF(fmt, ...) \ 29do { fprintf(stderr, "pl022: error: " fmt , ## __VA_ARGS__);} while (0) 30#endif 31 32#define PL022_CR1_LBM 0x01 33#define PL022_CR1_SSE 0x02 34#define PL022_CR1_MS 0x04 35#define PL022_CR1_SDO 0x08 36 37#define PL022_SR_TFE 0x01 38#define PL022_SR_TNF 0x02 39#define PL022_SR_RNE 0x04 40#define PL022_SR_RFF 0x08 41#define PL022_SR_BSY 0x10 42 43#define PL022_INT_ROR 0x01 44#define PL022_INT_RT 0x02 45#define PL022_INT_RX 0x04 46#define PL022_INT_TX 0x08 47 48static const unsigned char pl022_id[8] = 49 { 0x22, 0x10, 0x04, 0x00, 0x0d, 0xf0, 0x05, 0xb1 }; 50 51static void pl022_update(PL022State *s) 52{ 53 s->sr = 0; 54 if (s->tx_fifo_len == 0) 55 s->sr |= PL022_SR_TFE; 56 if (s->tx_fifo_len != 8) 57 s->sr |= PL022_SR_TNF; 58 if (s->rx_fifo_len != 0) 59 s->sr |= PL022_SR_RNE; 60 if (s->rx_fifo_len == 8) 61 s->sr |= PL022_SR_RFF; 62 if (s->tx_fifo_len) 63 s->sr |= PL022_SR_BSY; 64 s->is = 0; 65 if (s->rx_fifo_len >= 4) 66 s->is |= PL022_INT_RX; 67 if (s->tx_fifo_len <= 4) 68 s->is |= PL022_INT_TX; 69 70 qemu_set_irq(s->irq, (s->is & s->im) != 0); 71} 72 73static void pl022_xfer(PL022State *s) 74{ 75 int i; 76 int o; 77 int val; 78 79 if ((s->cr1 & PL022_CR1_SSE) == 0) { 80 pl022_update(s); 81 DPRINTF("Disabled\n"); 82 return; 83 } 84 85 DPRINTF("Maybe xfer %d/%d\n", s->tx_fifo_len, s->rx_fifo_len); 86 i = (s->tx_fifo_head - s->tx_fifo_len) & 7; 87 o = s->rx_fifo_head; 88 /* ??? We do not emulate the line speed. 89 This may break some applications. The are two problematic cases: 90 (a) A driver feeds data into the TX FIFO until it is full, 91 and only then drains the RX FIFO. On real hardware the CPU can 92 feed data fast enough that the RX fifo never gets chance to overflow. 93 (b) A driver transmits data, deliberately allowing the RX FIFO to 94 overflow because it ignores the RX data anyway. 95 96 We choose to support (a) by stalling the transmit engine if it would 97 cause the RX FIFO to overflow. In practice much transmit-only code 98 falls into (a) because it flushes the RX FIFO to determine when 99 the transfer has completed. */ 100 while (s->tx_fifo_len && s->rx_fifo_len < 8) { 101 DPRINTF("xfer\n"); 102 val = s->tx_fifo[i]; 103 if (s->cr1 & PL022_CR1_LBM) { 104 /* Loopback mode. */ 105 } else { 106 val = ssi_transfer(s->ssi, val); 107 } 108 s->rx_fifo[o] = val & s->bitmask; 109 i = (i + 1) & 7; 110 o = (o + 1) & 7; 111 s->tx_fifo_len--; 112 s->rx_fifo_len++; 113 } 114 s->rx_fifo_head = o; 115 pl022_update(s); 116} 117 118static uint64_t pl022_read(void *opaque, hwaddr offset, 119 unsigned size) 120{ 121 PL022State *s = (PL022State *)opaque; 122 int val; 123 124 if (offset >= 0xfe0 && offset < 0x1000) { 125 return pl022_id[(offset - 0xfe0) >> 2]; 126 } 127 switch (offset) { 128 case 0x00: /* CR0 */ 129 return s->cr0; 130 case 0x04: /* CR1 */ 131 return s->cr1; 132 case 0x08: /* DR */ 133 if (s->rx_fifo_len) { 134 val = s->rx_fifo[(s->rx_fifo_head - s->rx_fifo_len) & 7]; 135 DPRINTF("RX %02x\n", val); 136 s->rx_fifo_len--; 137 pl022_xfer(s); 138 } else { 139 val = 0; 140 } 141 return val; 142 case 0x0c: /* SR */ 143 return s->sr; 144 case 0x10: /* CPSR */ 145 return s->cpsr; 146 case 0x14: /* IMSC */ 147 return s->im; 148 case 0x18: /* RIS */ 149 return s->is; 150 case 0x1c: /* MIS */ 151 return s->im & s->is; 152 case 0x24: /* DMACR */ 153 /* Not implemented. */ 154 return 0; 155 default: 156 qemu_log_mask(LOG_GUEST_ERROR, 157 "pl022_read: Bad offset %x\n", (int)offset); 158 return 0; 159 } 160} 161 162static void pl022_write(void *opaque, hwaddr offset, 163 uint64_t value, unsigned size) 164{ 165 PL022State *s = (PL022State *)opaque; 166 167 switch (offset) { 168 case 0x00: /* CR0 */ 169 s->cr0 = value; 170 /* Clock rate and format are ignored. */ 171 s->bitmask = (1 << ((value & 15) + 1)) - 1; 172 break; 173 case 0x04: /* CR1 */ 174 s->cr1 = value; 175 if ((s->cr1 & (PL022_CR1_MS | PL022_CR1_SSE)) 176 == (PL022_CR1_MS | PL022_CR1_SSE)) { 177 BADF("SPI peripheral mode not implemented\n"); 178 } 179 pl022_xfer(s); 180 break; 181 case 0x08: /* DR */ 182 if (s->tx_fifo_len < 8) { 183 DPRINTF("TX %02x\n", (unsigned)value); 184 s->tx_fifo[s->tx_fifo_head] = value & s->bitmask; 185 s->tx_fifo_head = (s->tx_fifo_head + 1) & 7; 186 s->tx_fifo_len++; 187 pl022_xfer(s); 188 } 189 break; 190 case 0x10: /* CPSR */ 191 /* Prescaler. Ignored. */ 192 s->cpsr = value & 0xff; 193 break; 194 case 0x14: /* IMSC */ 195 s->im = value; 196 pl022_update(s); 197 break; 198 case 0x20: /* ICR */ 199 /* 200 * write-1-to-clear: bit 0 clears ROR, bit 1 clears RT; 201 * RX and TX interrupts cannot be cleared this way. 202 */ 203 value &= PL022_INT_ROR | PL022_INT_RT; 204 s->is &= ~value; 205 break; 206 case 0x24: /* DMACR */ 207 if (value) { 208 qemu_log_mask(LOG_UNIMP, "pl022: DMA not implemented\n"); 209 } 210 break; 211 default: 212 qemu_log_mask(LOG_GUEST_ERROR, 213 "pl022_write: Bad offset %x\n", (int)offset); 214 } 215} 216 217static void pl022_reset(DeviceState *dev) 218{ 219 PL022State *s = PL022(dev); 220 221 s->rx_fifo_len = 0; 222 s->tx_fifo_len = 0; 223 s->im = 0; 224 s->is = PL022_INT_TX; 225 s->sr = PL022_SR_TFE | PL022_SR_TNF; 226} 227 228static const MemoryRegionOps pl022_ops = { 229 .read = pl022_read, 230 .write = pl022_write, 231 .endianness = DEVICE_NATIVE_ENDIAN, 232}; 233 234static int pl022_post_load(void *opaque, int version_id) 235{ 236 PL022State *s = opaque; 237 238 if (s->tx_fifo_head < 0 || 239 s->tx_fifo_head >= ARRAY_SIZE(s->tx_fifo) || 240 s->rx_fifo_head < 0 || 241 s->rx_fifo_head >= ARRAY_SIZE(s->rx_fifo)) { 242 return -1; 243 } 244 return 0; 245} 246 247static const VMStateDescription vmstate_pl022 = { 248 .name = "pl022_ssp", 249 .version_id = 1, 250 .minimum_version_id = 1, 251 .post_load = pl022_post_load, 252 .fields = (VMStateField[]) { 253 VMSTATE_UINT32(cr0, PL022State), 254 VMSTATE_UINT32(cr1, PL022State), 255 VMSTATE_UINT32(bitmask, PL022State), 256 VMSTATE_UINT32(sr, PL022State), 257 VMSTATE_UINT32(cpsr, PL022State), 258 VMSTATE_UINT32(is, PL022State), 259 VMSTATE_UINT32(im, PL022State), 260 VMSTATE_INT32(tx_fifo_head, PL022State), 261 VMSTATE_INT32(rx_fifo_head, PL022State), 262 VMSTATE_INT32(tx_fifo_len, PL022State), 263 VMSTATE_INT32(rx_fifo_len, PL022State), 264 VMSTATE_UINT16(tx_fifo[0], PL022State), 265 VMSTATE_UINT16(rx_fifo[0], PL022State), 266 VMSTATE_UINT16(tx_fifo[1], PL022State), 267 VMSTATE_UINT16(rx_fifo[1], PL022State), 268 VMSTATE_UINT16(tx_fifo[2], PL022State), 269 VMSTATE_UINT16(rx_fifo[2], PL022State), 270 VMSTATE_UINT16(tx_fifo[3], PL022State), 271 VMSTATE_UINT16(rx_fifo[3], PL022State), 272 VMSTATE_UINT16(tx_fifo[4], PL022State), 273 VMSTATE_UINT16(rx_fifo[4], PL022State), 274 VMSTATE_UINT16(tx_fifo[5], PL022State), 275 VMSTATE_UINT16(rx_fifo[5], PL022State), 276 VMSTATE_UINT16(tx_fifo[6], PL022State), 277 VMSTATE_UINT16(rx_fifo[6], PL022State), 278 VMSTATE_UINT16(tx_fifo[7], PL022State), 279 VMSTATE_UINT16(rx_fifo[7], PL022State), 280 VMSTATE_END_OF_LIST() 281 } 282}; 283 284static void pl022_realize(DeviceState *dev, Error **errp) 285{ 286 SysBusDevice *sbd = SYS_BUS_DEVICE(dev); 287 PL022State *s = PL022(dev); 288 289 memory_region_init_io(&s->iomem, OBJECT(s), &pl022_ops, s, "pl022", 0x1000); 290 sysbus_init_mmio(sbd, &s->iomem); 291 sysbus_init_irq(sbd, &s->irq); 292 s->ssi = ssi_create_bus(dev, "ssi"); 293} 294 295static void pl022_class_init(ObjectClass *klass, void *data) 296{ 297 DeviceClass *dc = DEVICE_CLASS(klass); 298 299 dc->reset = pl022_reset; 300 dc->vmsd = &vmstate_pl022; 301 dc->realize = pl022_realize; 302} 303 304static const TypeInfo pl022_info = { 305 .name = TYPE_PL022, 306 .parent = TYPE_SYS_BUS_DEVICE, 307 .instance_size = sizeof(PL022State), 308 .class_init = pl022_class_init, 309}; 310 311static void pl022_register_types(void) 312{ 313 type_register_static(&pl022_info); 314} 315 316type_init(pl022_register_types)