1 /* 2 * Copyright (C) 2014 Freescale Semiconductor, Inc. All rights reserved. 3 * 4 * Author: Amit Tomar, <Amit.Tomar@freescale.com> 5 * 6 * Description: 7 * This file is derived from IMX I2C controller, 8 * by Jean-Christophe DUBOIS . 9 * 10 * Thanks to Scott Wood and Alexander Graf for their kind help on this. 11 * 12 * This program is free software; you can redistribute it and/or modify 13 * it under the terms of the GNU General Public License, version 2 or later, 14 * as published by the Free Software Foundation. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with this library; if not, see <http://www.gnu.org/licenses/>. 18 */ 19 20 #include "qemu/osdep.h" 21 #include "hw/i2c/i2c.h" 22 #include "hw/irq.h" 23 #include "qemu/log.h" 24 #include "qemu/module.h" 25 #include "hw/sysbus.h" 26 #include "migration/vmstate.h" 27 28 /* #define DEBUG_I2C */ 29 30 #ifdef DEBUG_I2C 31 #define DPRINTF(fmt, ...) \ 32 do { fprintf(stderr, "mpc_i2c[%s]: " fmt, __func__, ## __VA_ARGS__); \ 33 } while (0) 34 #else 35 #define DPRINTF(fmt, ...) do {} while (0) 36 #endif 37 38 #define TYPE_MPC_I2C "mpc-i2c" 39 #define MPC_I2C(obj) \ 40 OBJECT_CHECK(MPCI2CState, (obj), TYPE_MPC_I2C) 41 42 #define MPC_I2C_ADR 0x00 43 #define MPC_I2C_FDR 0x04 44 #define MPC_I2C_CR 0x08 45 #define MPC_I2C_SR 0x0c 46 #define MPC_I2C_DR 0x10 47 #define MPC_I2C_DFSRR 0x14 48 49 #define CCR_MEN (1 << 7) 50 #define CCR_MIEN (1 << 6) 51 #define CCR_MSTA (1 << 5) 52 #define CCR_MTX (1 << 4) 53 #define CCR_TXAK (1 << 3) 54 #define CCR_RSTA (1 << 2) 55 #define CCR_BCST (1 << 0) 56 57 #define CSR_MCF (1 << 7) 58 #define CSR_MAAS (1 << 6) 59 #define CSR_MBB (1 << 5) 60 #define CSR_MAL (1 << 4) 61 #define CSR_SRW (1 << 2) 62 #define CSR_MIF (1 << 1) 63 #define CSR_RXAK (1 << 0) 64 65 #define CADR_MASK 0xFE 66 #define CFDR_MASK 0x3F 67 #define CCR_MASK 0xFC 68 #define CSR_MASK 0xED 69 #define CDR_MASK 0xFF 70 71 #define CYCLE_RESET 0xFF 72 73 typedef struct MPCI2CState { 74 SysBusDevice parent_obj; 75 76 I2CBus *bus; 77 qemu_irq irq; 78 MemoryRegion iomem; 79 80 uint8_t address; 81 uint8_t adr; 82 uint8_t fdr; 83 uint8_t cr; 84 uint8_t sr; 85 uint8_t dr; 86 uint8_t dfssr; 87 } MPCI2CState; 88 89 static bool mpc_i2c_is_enabled(MPCI2CState *s) 90 { 91 return s->cr & CCR_MEN; 92 } 93 94 static bool mpc_i2c_is_master(MPCI2CState *s) 95 { 96 return s->cr & CCR_MSTA; 97 } 98 99 static bool mpc_i2c_direction_is_tx(MPCI2CState *s) 100 { 101 return s->cr & CCR_MTX; 102 } 103 104 static bool mpc_i2c_irq_pending(MPCI2CState *s) 105 { 106 return s->sr & CSR_MIF; 107 } 108 109 static bool mpc_i2c_irq_is_enabled(MPCI2CState *s) 110 { 111 return s->cr & CCR_MIEN; 112 } 113 114 static void mpc_i2c_reset(DeviceState *dev) 115 { 116 MPCI2CState *i2c = MPC_I2C(dev); 117 118 i2c->address = 0xFF; 119 i2c->adr = 0x00; 120 i2c->fdr = 0x00; 121 i2c->cr = 0x00; 122 i2c->sr = 0x81; 123 i2c->dr = 0x00; 124 } 125 126 static void mpc_i2c_irq(MPCI2CState *s) 127 { 128 bool irq_active = false; 129 130 if (mpc_i2c_is_enabled(s) && mpc_i2c_irq_is_enabled(s) 131 && mpc_i2c_irq_pending(s)) { 132 irq_active = true; 133 } 134 135 if (irq_active) { 136 qemu_irq_raise(s->irq); 137 } else { 138 qemu_irq_lower(s->irq); 139 } 140 } 141 142 static void mpc_i2c_soft_reset(MPCI2CState *s) 143 { 144 /* This is a soft reset. ADR is preserved during soft resets */ 145 uint8_t adr = s->adr; 146 mpc_i2c_reset(DEVICE(s)); 147 s->adr = adr; 148 } 149 150 static void mpc_i2c_address_send(MPCI2CState *s) 151 { 152 /* if returns non zero slave address is not right */ 153 if (i2c_start_transfer(s->bus, s->dr >> 1, s->dr & (0x01))) { 154 s->sr |= CSR_RXAK; 155 } else { 156 s->address = s->dr; 157 s->sr &= ~CSR_RXAK; 158 s->sr |= CSR_MCF; /* Set after Byte Transfer is completed */ 159 s->sr |= CSR_MIF; /* Set after Byte Transfer is completed */ 160 mpc_i2c_irq(s); 161 } 162 } 163 164 static void mpc_i2c_data_send(MPCI2CState *s) 165 { 166 if (i2c_send(s->bus, s->dr)) { 167 /* End of transfer */ 168 s->sr |= CSR_RXAK; 169 i2c_end_transfer(s->bus); 170 } else { 171 s->sr &= ~CSR_RXAK; 172 s->sr |= CSR_MCF; /* Set after Byte Transfer is completed */ 173 s->sr |= CSR_MIF; /* Set after Byte Transfer is completed */ 174 mpc_i2c_irq(s); 175 } 176 } 177 178 static void mpc_i2c_data_recive(MPCI2CState *s) 179 { 180 int ret; 181 /* get the next byte */ 182 ret = i2c_recv(s->bus); 183 if (ret >= 0) { 184 s->sr |= CSR_MCF; /* Set after Byte Transfer is completed */ 185 s->sr |= CSR_MIF; /* Set after Byte Transfer is completed */ 186 mpc_i2c_irq(s); 187 } else { 188 DPRINTF("read failed for device"); 189 ret = 0xff; 190 } 191 s->dr = ret; 192 } 193 194 static uint64_t mpc_i2c_read(void *opaque, hwaddr addr, unsigned size) 195 { 196 MPCI2CState *s = opaque; 197 uint8_t value; 198 199 switch (addr) { 200 case MPC_I2C_ADR: 201 value = s->adr; 202 break; 203 case MPC_I2C_FDR: 204 value = s->fdr; 205 break; 206 case MPC_I2C_CR: 207 value = s->cr; 208 break; 209 case MPC_I2C_SR: 210 value = s->sr; 211 break; 212 case MPC_I2C_DR: 213 value = s->dr; 214 if (mpc_i2c_is_master(s)) { /* master mode */ 215 if (mpc_i2c_direction_is_tx(s)) { 216 DPRINTF("MTX is set not in recv mode\n"); 217 } else { 218 mpc_i2c_data_recive(s); 219 } 220 } 221 break; 222 default: 223 value = 0; 224 DPRINTF("ERROR: Bad read addr 0x%x\n", (unsigned int)addr); 225 break; 226 } 227 228 DPRINTF("%s: addr " TARGET_FMT_plx " %02" PRIx32 "\n", __func__, 229 addr, value); 230 return (uint64_t)value; 231 } 232 233 static void mpc_i2c_write(void *opaque, hwaddr addr, 234 uint64_t value, unsigned size) 235 { 236 MPCI2CState *s = opaque; 237 238 DPRINTF("%s: addr " TARGET_FMT_plx " val %08" PRIx64 "\n", __func__, 239 addr, value); 240 switch (addr) { 241 case MPC_I2C_ADR: 242 s->adr = value & CADR_MASK; 243 break; 244 case MPC_I2C_FDR: 245 s->fdr = value & CFDR_MASK; 246 break; 247 case MPC_I2C_CR: 248 if (mpc_i2c_is_enabled(s) && ((value & CCR_MEN) == 0)) { 249 mpc_i2c_soft_reset(s); 250 break; 251 } 252 /* normal write */ 253 s->cr = value & CCR_MASK; 254 if (mpc_i2c_is_master(s)) { /* master mode */ 255 /* set the bus to busy after master is set as per RM */ 256 s->sr |= CSR_MBB; 257 } else { 258 /* bus is not busy anymore */ 259 s->sr &= ~CSR_MBB; 260 /* Reset the address for fresh write/read cycle */ 261 if (s->address != CYCLE_RESET) { 262 i2c_end_transfer(s->bus); 263 s->address = CYCLE_RESET; 264 } 265 } 266 /* For restart end the onging transfer */ 267 if (s->cr & CCR_RSTA) { 268 if (s->address != CYCLE_RESET) { 269 s->address = CYCLE_RESET; 270 i2c_end_transfer(s->bus); 271 s->cr &= ~CCR_RSTA; 272 } 273 } 274 break; 275 case MPC_I2C_SR: 276 s->sr = value & CSR_MASK; 277 /* Lower the interrupt */ 278 if (!(s->sr & CSR_MIF) || !(s->sr & CSR_MAL)) { 279 mpc_i2c_irq(s); 280 } 281 break; 282 case MPC_I2C_DR: 283 /* if the device is not enabled, nothing to do */ 284 if (!mpc_i2c_is_enabled(s)) { 285 break; 286 } 287 s->dr = value & CDR_MASK; 288 if (mpc_i2c_is_master(s)) { /* master mode */ 289 if (s->address == CYCLE_RESET) { 290 mpc_i2c_address_send(s); 291 } else { 292 mpc_i2c_data_send(s); 293 } 294 } 295 break; 296 case MPC_I2C_DFSRR: 297 s->dfssr = value; 298 break; 299 default: 300 DPRINTF("ERROR: Bad write addr 0x%x\n", (unsigned int)addr); 301 break; 302 } 303 } 304 305 static const MemoryRegionOps i2c_ops = { 306 .read = mpc_i2c_read, 307 .write = mpc_i2c_write, 308 .valid.max_access_size = 1, 309 .endianness = DEVICE_NATIVE_ENDIAN, 310 }; 311 312 static const VMStateDescription mpc_i2c_vmstate = { 313 .name = TYPE_MPC_I2C, 314 .version_id = 1, 315 .minimum_version_id = 1, 316 .fields = (VMStateField[]) { 317 VMSTATE_UINT8(address, MPCI2CState), 318 VMSTATE_UINT8(adr, MPCI2CState), 319 VMSTATE_UINT8(fdr, MPCI2CState), 320 VMSTATE_UINT8(cr, MPCI2CState), 321 VMSTATE_UINT8(sr, MPCI2CState), 322 VMSTATE_UINT8(dr, MPCI2CState), 323 VMSTATE_UINT8(dfssr, MPCI2CState), 324 VMSTATE_END_OF_LIST() 325 } 326 }; 327 328 static void mpc_i2c_realize(DeviceState *dev, Error **errp) 329 { 330 MPCI2CState *i2c = MPC_I2C(dev); 331 sysbus_init_irq(SYS_BUS_DEVICE(dev), &i2c->irq); 332 memory_region_init_io(&i2c->iomem, OBJECT(i2c), &i2c_ops, i2c, 333 "mpc-i2c", 0x14); 334 sysbus_init_mmio(SYS_BUS_DEVICE(dev), &i2c->iomem); 335 i2c->bus = i2c_init_bus(DEVICE(dev), "i2c"); 336 } 337 338 static void mpc_i2c_class_init(ObjectClass *klass, void *data) 339 { 340 DeviceClass *dc = DEVICE_CLASS(klass); 341 342 dc->vmsd = &mpc_i2c_vmstate ; 343 dc->reset = mpc_i2c_reset; 344 dc->realize = mpc_i2c_realize; 345 dc->desc = "MPC I2C Controller"; 346 } 347 348 static const TypeInfo mpc_i2c_type_info = { 349 .name = TYPE_MPC_I2C, 350 .parent = TYPE_SYS_BUS_DEVICE, 351 .instance_size = sizeof(MPCI2CState), 352 .class_init = mpc_i2c_class_init, 353 }; 354 355 static void mpc_i2c_register_types(void) 356 { 357 type_register_static(&mpc_i2c_type_info); 358 } 359 360 type_init(mpc_i2c_register_types) 361