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