1 /* 2 * Driver for the i2c controller on the Marvell line of host bridges 3 * (e.g, gt642[46]0, mv643[46]0, mv644[46]0, and Orion SoC family). 4 * 5 * Author: Mark A. Greer <mgreer@mvista.com> 6 * 7 * 2005 (c) MontaVista, Software, Inc. This file is licensed under 8 * the terms of the GNU General Public License version 2. This program 9 * is licensed "as is" without any warranty of any kind, whether express 10 * or implied. 11 */ 12 #include <linux/kernel.h> 13 #include <linux/slab.h> 14 #include <linux/module.h> 15 #include <linux/spinlock.h> 16 #include <linux/i2c.h> 17 #include <linux/interrupt.h> 18 #include <linux/mv643xx_i2c.h> 19 #include <linux/platform_device.h> 20 #include <linux/io.h> 21 #include <linux/of.h> 22 #include <linux/of_device.h> 23 #include <linux/of_irq.h> 24 #include <linux/clk.h> 25 #include <linux/err.h> 26 #include <linux/delay.h> 27 28 #define MV64XXX_I2C_ADDR_ADDR(val) ((val & 0x7f) << 1) 29 #define MV64XXX_I2C_BAUD_DIV_N(val) (val & 0x7) 30 #define MV64XXX_I2C_BAUD_DIV_M(val) ((val & 0xf) << 3) 31 32 #define MV64XXX_I2C_REG_CONTROL_ACK 0x00000004 33 #define MV64XXX_I2C_REG_CONTROL_IFLG 0x00000008 34 #define MV64XXX_I2C_REG_CONTROL_STOP 0x00000010 35 #define MV64XXX_I2C_REG_CONTROL_START 0x00000020 36 #define MV64XXX_I2C_REG_CONTROL_TWSIEN 0x00000040 37 #define MV64XXX_I2C_REG_CONTROL_INTEN 0x00000080 38 39 /* Ctlr status values */ 40 #define MV64XXX_I2C_STATUS_BUS_ERR 0x00 41 #define MV64XXX_I2C_STATUS_MAST_START 0x08 42 #define MV64XXX_I2C_STATUS_MAST_REPEAT_START 0x10 43 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK 0x18 44 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK 0x20 45 #define MV64XXX_I2C_STATUS_MAST_WR_ACK 0x28 46 #define MV64XXX_I2C_STATUS_MAST_WR_NO_ACK 0x30 47 #define MV64XXX_I2C_STATUS_MAST_LOST_ARB 0x38 48 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK 0x40 49 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK 0x48 50 #define MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK 0x50 51 #define MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK 0x58 52 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK 0xd0 53 #define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK 0xd8 54 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK 0xe0 55 #define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK 0xe8 56 #define MV64XXX_I2C_STATUS_NO_STATUS 0xf8 57 58 /* Register defines (I2C bridge) */ 59 #define MV64XXX_I2C_REG_TX_DATA_LO 0xc0 60 #define MV64XXX_I2C_REG_TX_DATA_HI 0xc4 61 #define MV64XXX_I2C_REG_RX_DATA_LO 0xc8 62 #define MV64XXX_I2C_REG_RX_DATA_HI 0xcc 63 #define MV64XXX_I2C_REG_BRIDGE_CONTROL 0xd0 64 #define MV64XXX_I2C_REG_BRIDGE_STATUS 0xd4 65 #define MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE 0xd8 66 #define MV64XXX_I2C_REG_BRIDGE_INTR_MASK 0xdC 67 #define MV64XXX_I2C_REG_BRIDGE_TIMING 0xe0 68 69 /* Bridge Control values */ 70 #define MV64XXX_I2C_BRIDGE_CONTROL_WR 0x00000001 71 #define MV64XXX_I2C_BRIDGE_CONTROL_RD 0x00000002 72 #define MV64XXX_I2C_BRIDGE_CONTROL_ADDR_SHIFT 2 73 #define MV64XXX_I2C_BRIDGE_CONTROL_ADDR_EXT 0x00001000 74 #define MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT 13 75 #define MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT 16 76 #define MV64XXX_I2C_BRIDGE_CONTROL_ENABLE 0x00080000 77 78 /* Bridge Status values */ 79 #define MV64XXX_I2C_BRIDGE_STATUS_ERROR 0x00000001 80 #define MV64XXX_I2C_STATUS_OFFLOAD_ERROR 0xf0000001 81 #define MV64XXX_I2C_STATUS_OFFLOAD_OK 0xf0000000 82 83 84 /* Driver states */ 85 enum { 86 MV64XXX_I2C_STATE_INVALID, 87 MV64XXX_I2C_STATE_IDLE, 88 MV64XXX_I2C_STATE_WAITING_FOR_START_COND, 89 MV64XXX_I2C_STATE_WAITING_FOR_RESTART, 90 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK, 91 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK, 92 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK, 93 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA, 94 }; 95 96 /* Driver actions */ 97 enum { 98 MV64XXX_I2C_ACTION_INVALID, 99 MV64XXX_I2C_ACTION_CONTINUE, 100 MV64XXX_I2C_ACTION_OFFLOAD_SEND_START, 101 MV64XXX_I2C_ACTION_SEND_START, 102 MV64XXX_I2C_ACTION_SEND_RESTART, 103 MV64XXX_I2C_ACTION_OFFLOAD_RESTART, 104 MV64XXX_I2C_ACTION_SEND_ADDR_1, 105 MV64XXX_I2C_ACTION_SEND_ADDR_2, 106 MV64XXX_I2C_ACTION_SEND_DATA, 107 MV64XXX_I2C_ACTION_RCV_DATA, 108 MV64XXX_I2C_ACTION_RCV_DATA_STOP, 109 MV64XXX_I2C_ACTION_SEND_STOP, 110 MV64XXX_I2C_ACTION_OFFLOAD_SEND_STOP, 111 }; 112 113 struct mv64xxx_i2c_regs { 114 u8 addr; 115 u8 ext_addr; 116 u8 data; 117 u8 control; 118 u8 status; 119 u8 clock; 120 u8 soft_reset; 121 }; 122 123 struct mv64xxx_i2c_data { 124 struct i2c_msg *msgs; 125 int num_msgs; 126 int irq; 127 u32 state; 128 u32 action; 129 u32 aborting; 130 u32 cntl_bits; 131 void __iomem *reg_base; 132 struct mv64xxx_i2c_regs reg_offsets; 133 u32 addr1; 134 u32 addr2; 135 u32 bytes_left; 136 u32 byte_posn; 137 u32 send_stop; 138 u32 block; 139 int rc; 140 u32 freq_m; 141 u32 freq_n; 142 #if defined(CONFIG_HAVE_CLK) 143 struct clk *clk; 144 #endif 145 wait_queue_head_t waitq; 146 spinlock_t lock; 147 struct i2c_msg *msg; 148 struct i2c_adapter adapter; 149 bool offload_enabled; 150 /* 5us delay in order to avoid repeated start timing violation */ 151 bool errata_delay; 152 }; 153 154 static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_mv64xxx = { 155 .addr = 0x00, 156 .ext_addr = 0x10, 157 .data = 0x04, 158 .control = 0x08, 159 .status = 0x0c, 160 .clock = 0x0c, 161 .soft_reset = 0x1c, 162 }; 163 164 static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_sun4i = { 165 .addr = 0x00, 166 .ext_addr = 0x04, 167 .data = 0x08, 168 .control = 0x0c, 169 .status = 0x10, 170 .clock = 0x14, 171 .soft_reset = 0x18, 172 }; 173 174 static void 175 mv64xxx_i2c_prepare_for_io(struct mv64xxx_i2c_data *drv_data, 176 struct i2c_msg *msg) 177 { 178 u32 dir = 0; 179 180 drv_data->msg = msg; 181 drv_data->byte_posn = 0; 182 drv_data->bytes_left = msg->len; 183 drv_data->aborting = 0; 184 drv_data->rc = 0; 185 drv_data->cntl_bits = MV64XXX_I2C_REG_CONTROL_ACK | 186 MV64XXX_I2C_REG_CONTROL_INTEN | MV64XXX_I2C_REG_CONTROL_TWSIEN; 187 188 if (msg->flags & I2C_M_RD) 189 dir = 1; 190 191 if (msg->flags & I2C_M_TEN) { 192 drv_data->addr1 = 0xf0 | (((u32)msg->addr & 0x300) >> 7) | dir; 193 drv_data->addr2 = (u32)msg->addr & 0xff; 194 } else { 195 drv_data->addr1 = MV64XXX_I2C_ADDR_ADDR((u32)msg->addr) | dir; 196 drv_data->addr2 = 0; 197 } 198 } 199 200 static int mv64xxx_i2c_offload_msg(struct mv64xxx_i2c_data *drv_data) 201 { 202 unsigned long data_reg_hi = 0; 203 unsigned long data_reg_lo = 0; 204 unsigned long ctrl_reg; 205 struct i2c_msg *msg = drv_data->msgs; 206 207 drv_data->msg = msg; 208 drv_data->byte_posn = 0; 209 drv_data->bytes_left = msg->len; 210 drv_data->aborting = 0; 211 drv_data->rc = 0; 212 /* Only regular transactions can be offloaded */ 213 if ((msg->flags & ~(I2C_M_TEN | I2C_M_RD)) != 0) 214 return -EINVAL; 215 216 /* Only 1-8 byte transfers can be offloaded */ 217 if (msg->len < 1 || msg->len > 8) 218 return -EINVAL; 219 220 /* Build transaction */ 221 ctrl_reg = MV64XXX_I2C_BRIDGE_CONTROL_ENABLE | 222 (msg->addr << MV64XXX_I2C_BRIDGE_CONTROL_ADDR_SHIFT); 223 224 if ((msg->flags & I2C_M_TEN) != 0) 225 ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_ADDR_EXT; 226 227 if ((msg->flags & I2C_M_RD) == 0) { 228 u8 local_buf[8] = { 0 }; 229 230 memcpy(local_buf, msg->buf, msg->len); 231 data_reg_lo = cpu_to_le32(*((u32 *)local_buf)); 232 data_reg_hi = cpu_to_le32(*((u32 *)(local_buf+4))); 233 234 ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_WR | 235 (msg->len - 1) << MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT; 236 237 writel(data_reg_lo, 238 drv_data->reg_base + MV64XXX_I2C_REG_TX_DATA_LO); 239 writel(data_reg_hi, 240 drv_data->reg_base + MV64XXX_I2C_REG_TX_DATA_HI); 241 242 } else { 243 ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_RD | 244 (msg->len - 1) << MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT; 245 } 246 247 /* Execute transaction */ 248 writel(ctrl_reg, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL); 249 250 return 0; 251 } 252 253 static void 254 mv64xxx_i2c_update_offload_data(struct mv64xxx_i2c_data *drv_data) 255 { 256 struct i2c_msg *msg = drv_data->msg; 257 258 if (msg->flags & I2C_M_RD) { 259 u32 data_reg_lo = readl(drv_data->reg_base + 260 MV64XXX_I2C_REG_RX_DATA_LO); 261 u32 data_reg_hi = readl(drv_data->reg_base + 262 MV64XXX_I2C_REG_RX_DATA_HI); 263 u8 local_buf[8] = { 0 }; 264 265 *((u32 *)local_buf) = le32_to_cpu(data_reg_lo); 266 *((u32 *)(local_buf+4)) = le32_to_cpu(data_reg_hi); 267 memcpy(msg->buf, local_buf, msg->len); 268 } 269 270 } 271 /* 272 ***************************************************************************** 273 * 274 * Finite State Machine & Interrupt Routines 275 * 276 ***************************************************************************** 277 */ 278 279 /* Reset hardware and initialize FSM */ 280 static void 281 mv64xxx_i2c_hw_init(struct mv64xxx_i2c_data *drv_data) 282 { 283 if (drv_data->offload_enabled) { 284 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL); 285 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_TIMING); 286 writel(0, drv_data->reg_base + 287 MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE); 288 writel(0, drv_data->reg_base + 289 MV64XXX_I2C_REG_BRIDGE_INTR_MASK); 290 } 291 292 writel(0, drv_data->reg_base + drv_data->reg_offsets.soft_reset); 293 writel(MV64XXX_I2C_BAUD_DIV_M(drv_data->freq_m) | MV64XXX_I2C_BAUD_DIV_N(drv_data->freq_n), 294 drv_data->reg_base + drv_data->reg_offsets.clock); 295 writel(0, drv_data->reg_base + drv_data->reg_offsets.addr); 296 writel(0, drv_data->reg_base + drv_data->reg_offsets.ext_addr); 297 writel(MV64XXX_I2C_REG_CONTROL_TWSIEN | MV64XXX_I2C_REG_CONTROL_STOP, 298 drv_data->reg_base + drv_data->reg_offsets.control); 299 drv_data->state = MV64XXX_I2C_STATE_IDLE; 300 } 301 302 static void 303 mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status) 304 { 305 /* 306 * If state is idle, then this is likely the remnants of an old 307 * operation that driver has given up on or the user has killed. 308 * If so, issue the stop condition and go to idle. 309 */ 310 if (drv_data->state == MV64XXX_I2C_STATE_IDLE) { 311 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; 312 return; 313 } 314 315 /* The status from the ctlr [mostly] tells us what to do next */ 316 switch (status) { 317 /* Start condition interrupt */ 318 case MV64XXX_I2C_STATUS_MAST_START: /* 0x08 */ 319 case MV64XXX_I2C_STATUS_MAST_REPEAT_START: /* 0x10 */ 320 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_1; 321 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK; 322 break; 323 324 /* Performing a write */ 325 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK: /* 0x18 */ 326 if (drv_data->msg->flags & I2C_M_TEN) { 327 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2; 328 drv_data->state = 329 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK; 330 break; 331 } 332 /* FALLTHRU */ 333 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK: /* 0xd0 */ 334 case MV64XXX_I2C_STATUS_MAST_WR_ACK: /* 0x28 */ 335 if ((drv_data->bytes_left == 0) 336 || (drv_data->aborting 337 && (drv_data->byte_posn != 0))) { 338 if (drv_data->send_stop || drv_data->aborting) { 339 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; 340 drv_data->state = MV64XXX_I2C_STATE_IDLE; 341 } else { 342 drv_data->action = 343 MV64XXX_I2C_ACTION_SEND_RESTART; 344 drv_data->state = 345 MV64XXX_I2C_STATE_WAITING_FOR_RESTART; 346 } 347 } else { 348 drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA; 349 drv_data->state = 350 MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK; 351 drv_data->bytes_left--; 352 } 353 break; 354 355 /* Performing a read */ 356 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK: /* 40 */ 357 if (drv_data->msg->flags & I2C_M_TEN) { 358 drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2; 359 drv_data->state = 360 MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK; 361 break; 362 } 363 /* FALLTHRU */ 364 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK: /* 0xe0 */ 365 if (drv_data->bytes_left == 0) { 366 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; 367 drv_data->state = MV64XXX_I2C_STATE_IDLE; 368 break; 369 } 370 /* FALLTHRU */ 371 case MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK: /* 0x50 */ 372 if (status != MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK) 373 drv_data->action = MV64XXX_I2C_ACTION_CONTINUE; 374 else { 375 drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA; 376 drv_data->bytes_left--; 377 } 378 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA; 379 380 if ((drv_data->bytes_left == 1) || drv_data->aborting) 381 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_ACK; 382 break; 383 384 case MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */ 385 drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA_STOP; 386 drv_data->state = MV64XXX_I2C_STATE_IDLE; 387 break; 388 389 case MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK: /* 0x20 */ 390 case MV64XXX_I2C_STATUS_MAST_WR_NO_ACK: /* 30 */ 391 case MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK: /* 48 */ 392 /* Doesn't seem to be a device at other end */ 393 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; 394 drv_data->state = MV64XXX_I2C_STATE_IDLE; 395 drv_data->rc = -ENXIO; 396 break; 397 398 case MV64XXX_I2C_STATUS_OFFLOAD_OK: 399 if (drv_data->send_stop || drv_data->aborting) { 400 drv_data->action = MV64XXX_I2C_ACTION_OFFLOAD_SEND_STOP; 401 drv_data->state = MV64XXX_I2C_STATE_IDLE; 402 } else { 403 drv_data->action = MV64XXX_I2C_ACTION_OFFLOAD_RESTART; 404 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_RESTART; 405 } 406 break; 407 408 default: 409 dev_err(&drv_data->adapter.dev, 410 "mv64xxx_i2c_fsm: Ctlr Error -- state: 0x%x, " 411 "status: 0x%x, addr: 0x%x, flags: 0x%x\n", 412 drv_data->state, status, drv_data->msg->addr, 413 drv_data->msg->flags); 414 drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP; 415 mv64xxx_i2c_hw_init(drv_data); 416 drv_data->rc = -EIO; 417 } 418 } 419 420 static void 421 mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) 422 { 423 switch(drv_data->action) { 424 case MV64XXX_I2C_ACTION_OFFLOAD_RESTART: 425 mv64xxx_i2c_update_offload_data(drv_data); 426 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL); 427 writel(0, drv_data->reg_base + 428 MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE); 429 /* FALLTHRU */ 430 case MV64XXX_I2C_ACTION_SEND_RESTART: 431 /* We should only get here if we have further messages */ 432 BUG_ON(drv_data->num_msgs == 0); 433 434 drv_data->msgs++; 435 drv_data->num_msgs--; 436 if (!(drv_data->offload_enabled && 437 mv64xxx_i2c_offload_msg(drv_data))) { 438 drv_data->cntl_bits |= MV64XXX_I2C_REG_CONTROL_START; 439 writel(drv_data->cntl_bits, 440 drv_data->reg_base + drv_data->reg_offsets.control); 441 442 /* Setup for the next message */ 443 mv64xxx_i2c_prepare_for_io(drv_data, drv_data->msgs); 444 } 445 if (drv_data->errata_delay) 446 udelay(5); 447 448 /* 449 * We're never at the start of the message here, and by this 450 * time it's already too late to do any protocol mangling. 451 * Thankfully, do not advertise support for that feature. 452 */ 453 drv_data->send_stop = drv_data->num_msgs == 1; 454 break; 455 456 case MV64XXX_I2C_ACTION_CONTINUE: 457 writel(drv_data->cntl_bits, 458 drv_data->reg_base + drv_data->reg_offsets.control); 459 break; 460 461 case MV64XXX_I2C_ACTION_OFFLOAD_SEND_START: 462 if (!mv64xxx_i2c_offload_msg(drv_data)) 463 break; 464 else 465 drv_data->action = MV64XXX_I2C_ACTION_SEND_START; 466 /* FALLTHRU */ 467 case MV64XXX_I2C_ACTION_SEND_START: 468 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_START, 469 drv_data->reg_base + drv_data->reg_offsets.control); 470 break; 471 472 case MV64XXX_I2C_ACTION_SEND_ADDR_1: 473 writel(drv_data->addr1, 474 drv_data->reg_base + drv_data->reg_offsets.data); 475 writel(drv_data->cntl_bits, 476 drv_data->reg_base + drv_data->reg_offsets.control); 477 break; 478 479 case MV64XXX_I2C_ACTION_SEND_ADDR_2: 480 writel(drv_data->addr2, 481 drv_data->reg_base + drv_data->reg_offsets.data); 482 writel(drv_data->cntl_bits, 483 drv_data->reg_base + drv_data->reg_offsets.control); 484 break; 485 486 case MV64XXX_I2C_ACTION_SEND_DATA: 487 writel(drv_data->msg->buf[drv_data->byte_posn++], 488 drv_data->reg_base + drv_data->reg_offsets.data); 489 writel(drv_data->cntl_bits, 490 drv_data->reg_base + drv_data->reg_offsets.control); 491 break; 492 493 case MV64XXX_I2C_ACTION_RCV_DATA: 494 drv_data->msg->buf[drv_data->byte_posn++] = 495 readl(drv_data->reg_base + drv_data->reg_offsets.data); 496 writel(drv_data->cntl_bits, 497 drv_data->reg_base + drv_data->reg_offsets.control); 498 break; 499 500 case MV64XXX_I2C_ACTION_RCV_DATA_STOP: 501 drv_data->msg->buf[drv_data->byte_posn++] = 502 readl(drv_data->reg_base + drv_data->reg_offsets.data); 503 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN; 504 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP, 505 drv_data->reg_base + drv_data->reg_offsets.control); 506 drv_data->block = 0; 507 if (drv_data->errata_delay) 508 udelay(5); 509 510 wake_up(&drv_data->waitq); 511 break; 512 513 case MV64XXX_I2C_ACTION_INVALID: 514 default: 515 dev_err(&drv_data->adapter.dev, 516 "mv64xxx_i2c_do_action: Invalid action: %d\n", 517 drv_data->action); 518 drv_data->rc = -EIO; 519 520 /* FALLTHRU */ 521 case MV64XXX_I2C_ACTION_SEND_STOP: 522 drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN; 523 writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP, 524 drv_data->reg_base + drv_data->reg_offsets.control); 525 drv_data->block = 0; 526 wake_up(&drv_data->waitq); 527 break; 528 529 case MV64XXX_I2C_ACTION_OFFLOAD_SEND_STOP: 530 mv64xxx_i2c_update_offload_data(drv_data); 531 writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL); 532 writel(0, drv_data->reg_base + 533 MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE); 534 drv_data->block = 0; 535 wake_up(&drv_data->waitq); 536 break; 537 } 538 } 539 540 static irqreturn_t 541 mv64xxx_i2c_intr(int irq, void *dev_id) 542 { 543 struct mv64xxx_i2c_data *drv_data = dev_id; 544 unsigned long flags; 545 u32 status; 546 irqreturn_t rc = IRQ_NONE; 547 548 spin_lock_irqsave(&drv_data->lock, flags); 549 550 if (drv_data->offload_enabled) { 551 while (readl(drv_data->reg_base + 552 MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE)) { 553 int reg_status = readl(drv_data->reg_base + 554 MV64XXX_I2C_REG_BRIDGE_STATUS); 555 if (reg_status & MV64XXX_I2C_BRIDGE_STATUS_ERROR) 556 status = MV64XXX_I2C_STATUS_OFFLOAD_ERROR; 557 else 558 status = MV64XXX_I2C_STATUS_OFFLOAD_OK; 559 mv64xxx_i2c_fsm(drv_data, status); 560 mv64xxx_i2c_do_action(drv_data); 561 rc = IRQ_HANDLED; 562 } 563 } 564 while (readl(drv_data->reg_base + drv_data->reg_offsets.control) & 565 MV64XXX_I2C_REG_CONTROL_IFLG) { 566 status = readl(drv_data->reg_base + drv_data->reg_offsets.status); 567 mv64xxx_i2c_fsm(drv_data, status); 568 mv64xxx_i2c_do_action(drv_data); 569 rc = IRQ_HANDLED; 570 } 571 spin_unlock_irqrestore(&drv_data->lock, flags); 572 573 return rc; 574 } 575 576 /* 577 ***************************************************************************** 578 * 579 * I2C Msg Execution Routines 580 * 581 ***************************************************************************** 582 */ 583 static void 584 mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data) 585 { 586 long time_left; 587 unsigned long flags; 588 char abort = 0; 589 590 time_left = wait_event_timeout(drv_data->waitq, 591 !drv_data->block, drv_data->adapter.timeout); 592 593 spin_lock_irqsave(&drv_data->lock, flags); 594 if (!time_left) { /* Timed out */ 595 drv_data->rc = -ETIMEDOUT; 596 abort = 1; 597 } else if (time_left < 0) { /* Interrupted/Error */ 598 drv_data->rc = time_left; /* errno value */ 599 abort = 1; 600 } 601 602 if (abort && drv_data->block) { 603 drv_data->aborting = 1; 604 spin_unlock_irqrestore(&drv_data->lock, flags); 605 606 time_left = wait_event_timeout(drv_data->waitq, 607 !drv_data->block, drv_data->adapter.timeout); 608 609 if ((time_left <= 0) && drv_data->block) { 610 drv_data->state = MV64XXX_I2C_STATE_IDLE; 611 dev_err(&drv_data->adapter.dev, 612 "mv64xxx: I2C bus locked, block: %d, " 613 "time_left: %d\n", drv_data->block, 614 (int)time_left); 615 mv64xxx_i2c_hw_init(drv_data); 616 } 617 } else 618 spin_unlock_irqrestore(&drv_data->lock, flags); 619 } 620 621 static int 622 mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg, 623 int is_last) 624 { 625 unsigned long flags; 626 627 spin_lock_irqsave(&drv_data->lock, flags); 628 if (drv_data->offload_enabled) { 629 drv_data->action = MV64XXX_I2C_ACTION_OFFLOAD_SEND_START; 630 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_START_COND; 631 } else { 632 mv64xxx_i2c_prepare_for_io(drv_data, msg); 633 634 drv_data->action = MV64XXX_I2C_ACTION_SEND_START; 635 drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_START_COND; 636 } 637 drv_data->send_stop = is_last; 638 drv_data->block = 1; 639 mv64xxx_i2c_do_action(drv_data); 640 spin_unlock_irqrestore(&drv_data->lock, flags); 641 642 mv64xxx_i2c_wait_for_completion(drv_data); 643 return drv_data->rc; 644 } 645 646 /* 647 ***************************************************************************** 648 * 649 * I2C Core Support Routines (Interface to higher level I2C code) 650 * 651 ***************************************************************************** 652 */ 653 static u32 654 mv64xxx_i2c_functionality(struct i2c_adapter *adap) 655 { 656 return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL; 657 } 658 659 static int 660 mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 661 { 662 struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap); 663 int rc, ret = num; 664 665 BUG_ON(drv_data->msgs != NULL); 666 drv_data->msgs = msgs; 667 drv_data->num_msgs = num; 668 669 rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[0], num == 1); 670 if (rc < 0) 671 ret = rc; 672 673 drv_data->num_msgs = 0; 674 drv_data->msgs = NULL; 675 676 return ret; 677 } 678 679 static const struct i2c_algorithm mv64xxx_i2c_algo = { 680 .master_xfer = mv64xxx_i2c_xfer, 681 .functionality = mv64xxx_i2c_functionality, 682 }; 683 684 /* 685 ***************************************************************************** 686 * 687 * Driver Interface & Early Init Routines 688 * 689 ***************************************************************************** 690 */ 691 static const struct of_device_id mv64xxx_i2c_of_match_table[] = { 692 { .compatible = "allwinner,sun4i-i2c", .data = &mv64xxx_i2c_regs_sun4i}, 693 { .compatible = "marvell,mv64xxx-i2c", .data = &mv64xxx_i2c_regs_mv64xxx}, 694 { .compatible = "marvell,mv78230-i2c", .data = &mv64xxx_i2c_regs_mv64xxx}, 695 { .compatible = "marvell,mv78230-a0-i2c", .data = &mv64xxx_i2c_regs_mv64xxx}, 696 {} 697 }; 698 MODULE_DEVICE_TABLE(of, mv64xxx_i2c_of_match_table); 699 700 #ifdef CONFIG_OF 701 #ifdef CONFIG_HAVE_CLK 702 static int 703 mv64xxx_calc_freq(const int tclk, const int n, const int m) 704 { 705 return tclk / (10 * (m + 1) * (2 << n)); 706 } 707 708 static bool 709 mv64xxx_find_baud_factors(const u32 req_freq, const u32 tclk, u32 *best_n, 710 u32 *best_m) 711 { 712 int freq, delta, best_delta = INT_MAX; 713 int m, n; 714 715 for (n = 0; n <= 7; n++) 716 for (m = 0; m <= 15; m++) { 717 freq = mv64xxx_calc_freq(tclk, n, m); 718 delta = req_freq - freq; 719 if (delta >= 0 && delta < best_delta) { 720 *best_m = m; 721 *best_n = n; 722 best_delta = delta; 723 } 724 if (best_delta == 0) 725 return true; 726 } 727 if (best_delta == INT_MAX) 728 return false; 729 return true; 730 } 731 #endif /* CONFIG_HAVE_CLK */ 732 733 static int 734 mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data, 735 struct device *dev) 736 { 737 /* CLK is mandatory when using DT to describe the i2c bus. We 738 * need to know tclk in order to calculate bus clock 739 * factors. 740 */ 741 #if !defined(CONFIG_HAVE_CLK) 742 /* Have OF but no CLK */ 743 return -ENODEV; 744 #else 745 const struct of_device_id *device; 746 struct device_node *np = dev->of_node; 747 u32 bus_freq, tclk; 748 int rc = 0; 749 750 if (IS_ERR(drv_data->clk)) { 751 rc = -ENODEV; 752 goto out; 753 } 754 tclk = clk_get_rate(drv_data->clk); 755 756 rc = of_property_read_u32(np, "clock-frequency", &bus_freq); 757 if (rc) 758 bus_freq = 100000; /* 100kHz by default */ 759 760 if (!mv64xxx_find_baud_factors(bus_freq, tclk, 761 &drv_data->freq_n, &drv_data->freq_m)) { 762 rc = -EINVAL; 763 goto out; 764 } 765 drv_data->irq = irq_of_parse_and_map(np, 0); 766 767 /* Its not yet defined how timeouts will be specified in device tree. 768 * So hard code the value to 1 second. 769 */ 770 drv_data->adapter.timeout = HZ; 771 772 device = of_match_device(mv64xxx_i2c_of_match_table, dev); 773 if (!device) 774 return -ENODEV; 775 776 memcpy(&drv_data->reg_offsets, device->data, sizeof(drv_data->reg_offsets)); 777 778 /* 779 * For controllers embedded in new SoCs activate the 780 * Transaction Generator support and the errata fix. 781 */ 782 if (of_device_is_compatible(np, "marvell,mv78230-i2c")) { 783 drv_data->offload_enabled = true; 784 drv_data->errata_delay = true; 785 } 786 787 if (of_device_is_compatible(np, "marvell,mv78230-a0-i2c")) { 788 drv_data->offload_enabled = false; 789 drv_data->errata_delay = true; 790 } 791 out: 792 return rc; 793 #endif 794 } 795 #else /* CONFIG_OF */ 796 static int 797 mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data, 798 struct device *dev) 799 { 800 return -ENODEV; 801 } 802 #endif /* CONFIG_OF */ 803 804 static int 805 mv64xxx_i2c_probe(struct platform_device *pd) 806 { 807 struct mv64xxx_i2c_data *drv_data; 808 struct mv64xxx_i2c_pdata *pdata = dev_get_platdata(&pd->dev); 809 struct resource *r; 810 int rc; 811 812 if ((!pdata && !pd->dev.of_node)) 813 return -ENODEV; 814 815 drv_data = devm_kzalloc(&pd->dev, sizeof(struct mv64xxx_i2c_data), 816 GFP_KERNEL); 817 if (!drv_data) 818 return -ENOMEM; 819 820 r = platform_get_resource(pd, IORESOURCE_MEM, 0); 821 drv_data->reg_base = devm_ioremap_resource(&pd->dev, r); 822 if (IS_ERR(drv_data->reg_base)) 823 return PTR_ERR(drv_data->reg_base); 824 825 strlcpy(drv_data->adapter.name, MV64XXX_I2C_CTLR_NAME " adapter", 826 sizeof(drv_data->adapter.name)); 827 828 init_waitqueue_head(&drv_data->waitq); 829 spin_lock_init(&drv_data->lock); 830 831 #if defined(CONFIG_HAVE_CLK) 832 /* Not all platforms have a clk */ 833 drv_data->clk = devm_clk_get(&pd->dev, NULL); 834 if (!IS_ERR(drv_data->clk)) { 835 clk_prepare(drv_data->clk); 836 clk_enable(drv_data->clk); 837 } 838 #endif 839 if (pdata) { 840 drv_data->freq_m = pdata->freq_m; 841 drv_data->freq_n = pdata->freq_n; 842 drv_data->irq = platform_get_irq(pd, 0); 843 drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout); 844 drv_data->offload_enabled = false; 845 memcpy(&drv_data->reg_offsets, &mv64xxx_i2c_regs_mv64xxx, sizeof(drv_data->reg_offsets)); 846 } else if (pd->dev.of_node) { 847 rc = mv64xxx_of_config(drv_data, &pd->dev); 848 if (rc) 849 goto exit_clk; 850 } 851 if (drv_data->irq < 0) { 852 rc = -ENXIO; 853 goto exit_clk; 854 } 855 856 drv_data->adapter.dev.parent = &pd->dev; 857 drv_data->adapter.algo = &mv64xxx_i2c_algo; 858 drv_data->adapter.owner = THIS_MODULE; 859 drv_data->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD; 860 drv_data->adapter.nr = pd->id; 861 drv_data->adapter.dev.of_node = pd->dev.of_node; 862 platform_set_drvdata(pd, drv_data); 863 i2c_set_adapdata(&drv_data->adapter, drv_data); 864 865 mv64xxx_i2c_hw_init(drv_data); 866 867 rc = request_irq(drv_data->irq, mv64xxx_i2c_intr, 0, 868 MV64XXX_I2C_CTLR_NAME, drv_data); 869 if (rc) { 870 dev_err(&drv_data->adapter.dev, 871 "mv64xxx: Can't register intr handler irq%d: %d\n", 872 drv_data->irq, rc); 873 goto exit_clk; 874 } else if ((rc = i2c_add_numbered_adapter(&drv_data->adapter)) != 0) { 875 dev_err(&drv_data->adapter.dev, 876 "mv64xxx: Can't add i2c adapter, rc: %d\n", -rc); 877 goto exit_free_irq; 878 } 879 880 return 0; 881 882 exit_free_irq: 883 free_irq(drv_data->irq, drv_data); 884 exit_clk: 885 #if defined(CONFIG_HAVE_CLK) 886 /* Not all platforms have a clk */ 887 if (!IS_ERR(drv_data->clk)) { 888 clk_disable(drv_data->clk); 889 clk_unprepare(drv_data->clk); 890 } 891 #endif 892 return rc; 893 } 894 895 static int 896 mv64xxx_i2c_remove(struct platform_device *dev) 897 { 898 struct mv64xxx_i2c_data *drv_data = platform_get_drvdata(dev); 899 900 i2c_del_adapter(&drv_data->adapter); 901 free_irq(drv_data->irq, drv_data); 902 #if defined(CONFIG_HAVE_CLK) 903 /* Not all platforms have a clk */ 904 if (!IS_ERR(drv_data->clk)) { 905 clk_disable(drv_data->clk); 906 clk_unprepare(drv_data->clk); 907 } 908 #endif 909 910 return 0; 911 } 912 913 static struct platform_driver mv64xxx_i2c_driver = { 914 .probe = mv64xxx_i2c_probe, 915 .remove = mv64xxx_i2c_remove, 916 .driver = { 917 .owner = THIS_MODULE, 918 .name = MV64XXX_I2C_CTLR_NAME, 919 .of_match_table = mv64xxx_i2c_of_match_table, 920 }, 921 }; 922 923 module_platform_driver(mv64xxx_i2c_driver); 924 925 MODULE_AUTHOR("Mark A. Greer <mgreer@mvista.com>"); 926 MODULE_DESCRIPTION("Marvell mv64xxx host bridge i2c ctlr driver"); 927 MODULE_LICENSE("GPL"); 928