1 // SPDX-License-Identifier: GPL-2.0-only 2 // Copyright (C) 2014 Broadcom Corporation 3 4 #include <linux/delay.h> 5 #include <linux/i2c.h> 6 #include <linux/interrupt.h> 7 #include <linux/io.h> 8 #include <linux/kernel.h> 9 #include <linux/module.h> 10 #include <linux/of.h> 11 #include <linux/platform_device.h> 12 #include <linux/slab.h> 13 14 #define IDM_CTRL_DIRECT_OFFSET 0x00 15 #define CFG_OFFSET 0x00 16 #define CFG_RESET_SHIFT 31 17 #define CFG_EN_SHIFT 30 18 #define CFG_SLAVE_ADDR_0_SHIFT 28 19 #define CFG_M_RETRY_CNT_SHIFT 16 20 #define CFG_M_RETRY_CNT_MASK 0x0f 21 22 #define TIM_CFG_OFFSET 0x04 23 #define TIM_CFG_MODE_400_SHIFT 31 24 #define TIM_RAND_SLAVE_STRETCH_SHIFT 24 25 #define TIM_RAND_SLAVE_STRETCH_MASK 0x7f 26 #define TIM_PERIODIC_SLAVE_STRETCH_SHIFT 16 27 #define TIM_PERIODIC_SLAVE_STRETCH_MASK 0x7f 28 29 #define S_CFG_SMBUS_ADDR_OFFSET 0x08 30 #define S_CFG_EN_NIC_SMB_ADDR3_SHIFT 31 31 #define S_CFG_NIC_SMB_ADDR3_SHIFT 24 32 #define S_CFG_NIC_SMB_ADDR3_MASK 0x7f 33 #define S_CFG_EN_NIC_SMB_ADDR2_SHIFT 23 34 #define S_CFG_NIC_SMB_ADDR2_SHIFT 16 35 #define S_CFG_NIC_SMB_ADDR2_MASK 0x7f 36 #define S_CFG_EN_NIC_SMB_ADDR1_SHIFT 15 37 #define S_CFG_NIC_SMB_ADDR1_SHIFT 8 38 #define S_CFG_NIC_SMB_ADDR1_MASK 0x7f 39 #define S_CFG_EN_NIC_SMB_ADDR0_SHIFT 7 40 #define S_CFG_NIC_SMB_ADDR0_SHIFT 0 41 #define S_CFG_NIC_SMB_ADDR0_MASK 0x7f 42 43 #define M_FIFO_CTRL_OFFSET 0x0c 44 #define M_FIFO_RX_FLUSH_SHIFT 31 45 #define M_FIFO_TX_FLUSH_SHIFT 30 46 #define M_FIFO_RX_CNT_SHIFT 16 47 #define M_FIFO_RX_CNT_MASK 0x7f 48 #define M_FIFO_RX_THLD_SHIFT 8 49 #define M_FIFO_RX_THLD_MASK 0x3f 50 51 #define S_FIFO_CTRL_OFFSET 0x10 52 #define S_FIFO_RX_FLUSH_SHIFT 31 53 #define S_FIFO_TX_FLUSH_SHIFT 30 54 #define S_FIFO_RX_CNT_SHIFT 16 55 #define S_FIFO_RX_CNT_MASK 0x7f 56 #define S_FIFO_RX_THLD_SHIFT 8 57 #define S_FIFO_RX_THLD_MASK 0x3f 58 59 #define M_CMD_OFFSET 0x30 60 #define M_CMD_START_BUSY_SHIFT 31 61 #define M_CMD_STATUS_SHIFT 25 62 #define M_CMD_STATUS_MASK 0x07 63 #define M_CMD_STATUS_SUCCESS 0x0 64 #define M_CMD_STATUS_LOST_ARB 0x1 65 #define M_CMD_STATUS_NACK_ADDR 0x2 66 #define M_CMD_STATUS_NACK_DATA 0x3 67 #define M_CMD_STATUS_TIMEOUT 0x4 68 #define M_CMD_STATUS_FIFO_UNDERRUN 0x5 69 #define M_CMD_STATUS_RX_FIFO_FULL 0x6 70 #define M_CMD_PROTOCOL_SHIFT 9 71 #define M_CMD_PROTOCOL_MASK 0xf 72 #define M_CMD_PROTOCOL_QUICK 0x0 73 #define M_CMD_PROTOCOL_BLK_WR 0x7 74 #define M_CMD_PROTOCOL_BLK_RD 0x8 75 #define M_CMD_PROTOCOL_PROCESS 0xa 76 #define M_CMD_PEC_SHIFT 8 77 #define M_CMD_RD_CNT_SHIFT 0 78 #define M_CMD_RD_CNT_MASK 0xff 79 80 #define S_CMD_OFFSET 0x34 81 #define S_CMD_START_BUSY_SHIFT 31 82 #define S_CMD_STATUS_SHIFT 23 83 #define S_CMD_STATUS_MASK 0x07 84 #define S_CMD_STATUS_SUCCESS 0x0 85 #define S_CMD_STATUS_TIMEOUT 0x5 86 #define S_CMD_STATUS_MASTER_ABORT 0x7 87 88 #define IE_OFFSET 0x38 89 #define IE_M_RX_FIFO_FULL_SHIFT 31 90 #define IE_M_RX_THLD_SHIFT 30 91 #define IE_M_START_BUSY_SHIFT 28 92 #define IE_M_TX_UNDERRUN_SHIFT 27 93 #define IE_S_RX_FIFO_FULL_SHIFT 26 94 #define IE_S_RX_THLD_SHIFT 25 95 #define IE_S_RX_EVENT_SHIFT 24 96 #define IE_S_START_BUSY_SHIFT 23 97 #define IE_S_TX_UNDERRUN_SHIFT 22 98 #define IE_S_RD_EVENT_SHIFT 21 99 100 #define IS_OFFSET 0x3c 101 #define IS_M_RX_FIFO_FULL_SHIFT 31 102 #define IS_M_RX_THLD_SHIFT 30 103 #define IS_M_START_BUSY_SHIFT 28 104 #define IS_M_TX_UNDERRUN_SHIFT 27 105 #define IS_S_RX_FIFO_FULL_SHIFT 26 106 #define IS_S_RX_THLD_SHIFT 25 107 #define IS_S_RX_EVENT_SHIFT 24 108 #define IS_S_START_BUSY_SHIFT 23 109 #define IS_S_TX_UNDERRUN_SHIFT 22 110 #define IS_S_RD_EVENT_SHIFT 21 111 112 #define M_TX_OFFSET 0x40 113 #define M_TX_WR_STATUS_SHIFT 31 114 #define M_TX_DATA_SHIFT 0 115 #define M_TX_DATA_MASK 0xff 116 117 #define M_RX_OFFSET 0x44 118 #define M_RX_STATUS_SHIFT 30 119 #define M_RX_STATUS_MASK 0x03 120 #define M_RX_PEC_ERR_SHIFT 29 121 #define M_RX_DATA_SHIFT 0 122 #define M_RX_DATA_MASK 0xff 123 124 #define S_TX_OFFSET 0x48 125 #define S_TX_WR_STATUS_SHIFT 31 126 #define S_TX_DATA_SHIFT 0 127 #define S_TX_DATA_MASK 0xff 128 129 #define S_RX_OFFSET 0x4c 130 #define S_RX_STATUS_SHIFT 30 131 #define S_RX_STATUS_MASK 0x03 132 #define S_RX_PEC_ERR_SHIFT 29 133 #define S_RX_DATA_SHIFT 0 134 #define S_RX_DATA_MASK 0xff 135 136 #define I2C_TIMEOUT_MSEC 50000 137 #define M_TX_RX_FIFO_SIZE 64 138 #define M_RX_FIFO_MAX_THLD_VALUE (M_TX_RX_FIFO_SIZE - 1) 139 140 #define M_RX_MAX_READ_LEN 255 141 #define M_RX_FIFO_THLD_VALUE 50 142 143 #define IE_M_ALL_INTERRUPT_SHIFT 27 144 #define IE_M_ALL_INTERRUPT_MASK 0x1e 145 146 #define SLAVE_READ_WRITE_BIT_MASK 0x1 147 #define SLAVE_READ_WRITE_BIT_SHIFT 0x1 148 #define SLAVE_MAX_SIZE_TRANSACTION 64 149 #define SLAVE_CLOCK_STRETCH_TIME 25 150 151 #define IE_S_ALL_INTERRUPT_SHIFT 21 152 #define IE_S_ALL_INTERRUPT_MASK 0x3f 153 /* 154 * It takes ~18us to reading 10bytes of data, hence to keep tasklet 155 * running for less time, max slave read per tasklet is set to 10 bytes. 156 */ 157 #define MAX_SLAVE_RX_PER_INT 10 158 159 enum i2c_slave_read_status { 160 I2C_SLAVE_RX_FIFO_EMPTY = 0, 161 I2C_SLAVE_RX_START, 162 I2C_SLAVE_RX_DATA, 163 I2C_SLAVE_RX_END, 164 }; 165 166 enum bus_speed_index { 167 I2C_SPD_100K = 0, 168 I2C_SPD_400K, 169 }; 170 171 enum bcm_iproc_i2c_type { 172 IPROC_I2C, 173 IPROC_I2C_NIC 174 }; 175 176 struct bcm_iproc_i2c_dev { 177 struct device *device; 178 enum bcm_iproc_i2c_type type; 179 int irq; 180 181 void __iomem *base; 182 void __iomem *idm_base; 183 184 u32 ape_addr_mask; 185 186 /* lock for indirect access through IDM */ 187 spinlock_t idm_lock; 188 189 struct i2c_adapter adapter; 190 unsigned int bus_speed; 191 192 struct completion done; 193 int xfer_is_done; 194 195 struct i2c_msg *msg; 196 197 struct i2c_client *slave; 198 199 /* bytes that have been transferred */ 200 unsigned int tx_bytes; 201 /* bytes that have been read */ 202 unsigned int rx_bytes; 203 unsigned int thld_bytes; 204 205 bool slave_rx_only; 206 bool rx_start_rcvd; 207 bool slave_read_complete; 208 u32 tx_underrun; 209 u32 slave_int_mask; 210 struct tasklet_struct slave_rx_tasklet; 211 }; 212 213 /* tasklet to process slave rx data */ 214 static void slave_rx_tasklet_fn(unsigned long); 215 216 /* 217 * Can be expanded in the future if more interrupt status bits are utilized 218 */ 219 #define ISR_MASK (BIT(IS_M_START_BUSY_SHIFT) | BIT(IS_M_TX_UNDERRUN_SHIFT)\ 220 | BIT(IS_M_RX_THLD_SHIFT)) 221 222 #define ISR_MASK_SLAVE (BIT(IS_S_START_BUSY_SHIFT)\ 223 | BIT(IS_S_RX_EVENT_SHIFT) | BIT(IS_S_RD_EVENT_SHIFT)\ 224 | BIT(IS_S_TX_UNDERRUN_SHIFT) | BIT(IS_S_RX_FIFO_FULL_SHIFT)\ 225 | BIT(IS_S_RX_THLD_SHIFT)) 226 227 static int bcm_iproc_i2c_reg_slave(struct i2c_client *slave); 228 static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave); 229 static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c, 230 bool enable); 231 232 static inline u32 iproc_i2c_rd_reg(struct bcm_iproc_i2c_dev *iproc_i2c, 233 u32 offset) 234 { 235 u32 val; 236 unsigned long flags; 237 238 if (iproc_i2c->idm_base) { 239 spin_lock_irqsave(&iproc_i2c->idm_lock, flags); 240 writel(iproc_i2c->ape_addr_mask, 241 iproc_i2c->idm_base + IDM_CTRL_DIRECT_OFFSET); 242 val = readl(iproc_i2c->base + offset); 243 spin_unlock_irqrestore(&iproc_i2c->idm_lock, flags); 244 } else { 245 val = readl(iproc_i2c->base + offset); 246 } 247 248 return val; 249 } 250 251 static inline void iproc_i2c_wr_reg(struct bcm_iproc_i2c_dev *iproc_i2c, 252 u32 offset, u32 val) 253 { 254 unsigned long flags; 255 256 if (iproc_i2c->idm_base) { 257 spin_lock_irqsave(&iproc_i2c->idm_lock, flags); 258 writel(iproc_i2c->ape_addr_mask, 259 iproc_i2c->idm_base + IDM_CTRL_DIRECT_OFFSET); 260 writel(val, iproc_i2c->base + offset); 261 spin_unlock_irqrestore(&iproc_i2c->idm_lock, flags); 262 } else { 263 writel(val, iproc_i2c->base + offset); 264 } 265 } 266 267 static void bcm_iproc_i2c_slave_init( 268 struct bcm_iproc_i2c_dev *iproc_i2c, bool need_reset) 269 { 270 u32 val; 271 272 iproc_i2c->tx_underrun = 0; 273 if (need_reset) { 274 /* put controller in reset */ 275 val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET); 276 val |= BIT(CFG_RESET_SHIFT); 277 iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val); 278 279 /* wait 100 usec per spec */ 280 udelay(100); 281 282 /* bring controller out of reset */ 283 val &= ~(BIT(CFG_RESET_SHIFT)); 284 iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val); 285 } 286 287 /* flush TX/RX FIFOs */ 288 val = (BIT(S_FIFO_RX_FLUSH_SHIFT) | BIT(S_FIFO_TX_FLUSH_SHIFT)); 289 iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, val); 290 291 /* Maximum slave stretch time */ 292 val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET); 293 val &= ~(TIM_RAND_SLAVE_STRETCH_MASK << TIM_RAND_SLAVE_STRETCH_SHIFT); 294 val |= (SLAVE_CLOCK_STRETCH_TIME << TIM_RAND_SLAVE_STRETCH_SHIFT); 295 iproc_i2c_wr_reg(iproc_i2c, TIM_CFG_OFFSET, val); 296 297 /* Configure the slave address */ 298 val = iproc_i2c_rd_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET); 299 val |= BIT(S_CFG_EN_NIC_SMB_ADDR3_SHIFT); 300 val &= ~(S_CFG_NIC_SMB_ADDR3_MASK << S_CFG_NIC_SMB_ADDR3_SHIFT); 301 val |= (iproc_i2c->slave->addr << S_CFG_NIC_SMB_ADDR3_SHIFT); 302 iproc_i2c_wr_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET, val); 303 304 /* clear all pending slave interrupts */ 305 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, ISR_MASK_SLAVE); 306 307 /* Enable interrupt register to indicate a valid byte in receive fifo */ 308 val = BIT(IE_S_RX_EVENT_SHIFT); 309 /* Enable interrupt register to indicate Slave Rx FIFO Full */ 310 val |= BIT(IE_S_RX_FIFO_FULL_SHIFT); 311 /* Enable interrupt register to indicate a Master read transaction */ 312 val |= BIT(IE_S_RD_EVENT_SHIFT); 313 /* Enable interrupt register for the Slave BUSY command */ 314 val |= BIT(IE_S_START_BUSY_SHIFT); 315 iproc_i2c->slave_int_mask = val; 316 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val); 317 } 318 319 static bool bcm_iproc_i2c_check_slave_status 320 (struct bcm_iproc_i2c_dev *iproc_i2c, u32 status) 321 { 322 u32 val; 323 bool recover = false; 324 325 /* check slave transmit status only if slave is transmitting */ 326 if (!iproc_i2c->slave_rx_only) { 327 val = iproc_i2c_rd_reg(iproc_i2c, S_CMD_OFFSET); 328 /* status is valid only when START_BUSY is cleared */ 329 if (!(val & BIT(S_CMD_START_BUSY_SHIFT))) { 330 val = (val >> S_CMD_STATUS_SHIFT) & S_CMD_STATUS_MASK; 331 if (val == S_CMD_STATUS_TIMEOUT || 332 val == S_CMD_STATUS_MASTER_ABORT) { 333 dev_warn(iproc_i2c->device, 334 (val == S_CMD_STATUS_TIMEOUT) ? 335 "slave random stretch time timeout\n" : 336 "Master aborted read transaction\n"); 337 recover = true; 338 } 339 } 340 } 341 342 /* RX_EVENT is not valid when START_BUSY is set */ 343 if ((status & BIT(IS_S_RX_EVENT_SHIFT)) && 344 (status & BIT(IS_S_START_BUSY_SHIFT))) { 345 dev_warn(iproc_i2c->device, "Slave aborted read transaction\n"); 346 recover = true; 347 } 348 349 if (recover) { 350 /* re-initialize i2c for recovery */ 351 bcm_iproc_i2c_enable_disable(iproc_i2c, false); 352 bcm_iproc_i2c_slave_init(iproc_i2c, true); 353 bcm_iproc_i2c_enable_disable(iproc_i2c, true); 354 } 355 356 return recover; 357 } 358 359 static void bcm_iproc_i2c_slave_read(struct bcm_iproc_i2c_dev *iproc_i2c) 360 { 361 u8 rx_data, rx_status; 362 u32 rx_bytes = 0; 363 u32 val; 364 365 while (rx_bytes < MAX_SLAVE_RX_PER_INT) { 366 val = iproc_i2c_rd_reg(iproc_i2c, S_RX_OFFSET); 367 rx_status = (val >> S_RX_STATUS_SHIFT) & S_RX_STATUS_MASK; 368 rx_data = ((val >> S_RX_DATA_SHIFT) & S_RX_DATA_MASK); 369 370 if (rx_status == I2C_SLAVE_RX_START) { 371 /* Start of SMBUS Master write */ 372 i2c_slave_event(iproc_i2c->slave, 373 I2C_SLAVE_WRITE_REQUESTED, &rx_data); 374 iproc_i2c->rx_start_rcvd = true; 375 iproc_i2c->slave_read_complete = false; 376 } else if (rx_status == I2C_SLAVE_RX_DATA && 377 iproc_i2c->rx_start_rcvd) { 378 /* Middle of SMBUS Master write */ 379 i2c_slave_event(iproc_i2c->slave, 380 I2C_SLAVE_WRITE_RECEIVED, &rx_data); 381 } else if (rx_status == I2C_SLAVE_RX_END && 382 iproc_i2c->rx_start_rcvd) { 383 /* End of SMBUS Master write */ 384 if (iproc_i2c->slave_rx_only) 385 i2c_slave_event(iproc_i2c->slave, 386 I2C_SLAVE_WRITE_RECEIVED, 387 &rx_data); 388 389 i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP, 390 &rx_data); 391 } else if (rx_status == I2C_SLAVE_RX_FIFO_EMPTY) { 392 iproc_i2c->rx_start_rcvd = false; 393 iproc_i2c->slave_read_complete = true; 394 break; 395 } 396 397 rx_bytes++; 398 } 399 } 400 401 static void slave_rx_tasklet_fn(unsigned long data) 402 { 403 struct bcm_iproc_i2c_dev *iproc_i2c = (struct bcm_iproc_i2c_dev *)data; 404 u32 int_clr; 405 406 bcm_iproc_i2c_slave_read(iproc_i2c); 407 408 /* clear pending IS_S_RX_EVENT_SHIFT interrupt */ 409 int_clr = BIT(IS_S_RX_EVENT_SHIFT); 410 411 if (!iproc_i2c->slave_rx_only && iproc_i2c->slave_read_complete) { 412 /* 413 * In case of single byte master-read request, 414 * IS_S_TX_UNDERRUN_SHIFT event is generated before 415 * IS_S_START_BUSY_SHIFT event. Hence start slave data send 416 * from first IS_S_TX_UNDERRUN_SHIFT event. 417 * 418 * This means don't send any data from slave when 419 * IS_S_RD_EVENT_SHIFT event is generated else it will increment 420 * eeprom or other backend slave driver read pointer twice. 421 */ 422 iproc_i2c->tx_underrun = 0; 423 iproc_i2c->slave_int_mask |= BIT(IE_S_TX_UNDERRUN_SHIFT); 424 425 /* clear IS_S_RD_EVENT_SHIFT interrupt */ 426 int_clr |= BIT(IS_S_RD_EVENT_SHIFT); 427 } 428 429 /* clear slave interrupt */ 430 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, int_clr); 431 /* enable slave interrupts */ 432 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, iproc_i2c->slave_int_mask); 433 } 434 435 static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c, 436 u32 status) 437 { 438 u32 val; 439 u8 value; 440 441 442 if (status & BIT(IS_S_TX_UNDERRUN_SHIFT)) { 443 iproc_i2c->tx_underrun++; 444 if (iproc_i2c->tx_underrun == 1) 445 /* Start of SMBUS for Master Read */ 446 i2c_slave_event(iproc_i2c->slave, 447 I2C_SLAVE_READ_REQUESTED, 448 &value); 449 else 450 /* Master read other than start */ 451 i2c_slave_event(iproc_i2c->slave, 452 I2C_SLAVE_READ_PROCESSED, 453 &value); 454 455 iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, value); 456 /* start transfer */ 457 val = BIT(S_CMD_START_BUSY_SHIFT); 458 iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val); 459 460 /* clear interrupt */ 461 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, 462 BIT(IS_S_TX_UNDERRUN_SHIFT)); 463 } 464 465 /* Stop received from master in case of master read transaction */ 466 if (status & BIT(IS_S_START_BUSY_SHIFT)) { 467 /* 468 * Disable interrupt for TX FIFO becomes empty and 469 * less than PKT_LENGTH bytes were output on the SMBUS 470 */ 471 iproc_i2c->slave_int_mask &= ~BIT(IE_S_TX_UNDERRUN_SHIFT); 472 val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); 473 val &= ~BIT(IE_S_TX_UNDERRUN_SHIFT); 474 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val); 475 476 /* End of SMBUS for Master Read */ 477 val = BIT(S_TX_WR_STATUS_SHIFT); 478 iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, val); 479 480 val = BIT(S_CMD_START_BUSY_SHIFT); 481 iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val); 482 483 /* flush TX FIFOs */ 484 val = iproc_i2c_rd_reg(iproc_i2c, S_FIFO_CTRL_OFFSET); 485 val |= (BIT(S_FIFO_TX_FLUSH_SHIFT)); 486 iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, val); 487 488 i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP, &value); 489 490 /* clear interrupt */ 491 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, 492 BIT(IS_S_START_BUSY_SHIFT)); 493 } 494 495 /* if the controller has been reset, immediately return from the ISR */ 496 if (bcm_iproc_i2c_check_slave_status(iproc_i2c, status)) 497 return true; 498 499 /* 500 * Slave events in case of master-write, master-write-read and, 501 * master-read 502 * 503 * Master-write : only IS_S_RX_EVENT_SHIFT event 504 * Master-write-read: both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT 505 * events 506 * Master-read : both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT 507 * events or only IS_S_RD_EVENT_SHIFT 508 * 509 * iproc has a slave rx fifo size of 64 bytes. Rx fifo full interrupt 510 * (IS_S_RX_FIFO_FULL_SHIFT) will be generated when RX fifo becomes 511 * full. This can happen if Master issues write requests of more than 512 * 64 bytes. 513 */ 514 if (status & BIT(IS_S_RX_EVENT_SHIFT) || 515 status & BIT(IS_S_RD_EVENT_SHIFT) || 516 status & BIT(IS_S_RX_FIFO_FULL_SHIFT)) { 517 /* disable slave interrupts */ 518 val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); 519 val &= ~iproc_i2c->slave_int_mask; 520 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val); 521 522 if (status & BIT(IS_S_RD_EVENT_SHIFT)) 523 /* Master-write-read request */ 524 iproc_i2c->slave_rx_only = false; 525 else 526 /* Master-write request only */ 527 iproc_i2c->slave_rx_only = true; 528 529 /* schedule tasklet to read data later */ 530 tasklet_schedule(&iproc_i2c->slave_rx_tasklet); 531 532 /* clear IS_S_RX_FIFO_FULL_SHIFT interrupt */ 533 if (status & BIT(IS_S_RX_FIFO_FULL_SHIFT)) { 534 val = BIT(IS_S_RX_FIFO_FULL_SHIFT); 535 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, val); 536 } 537 } 538 539 return true; 540 } 541 542 static void bcm_iproc_i2c_read_valid_bytes(struct bcm_iproc_i2c_dev *iproc_i2c) 543 { 544 struct i2c_msg *msg = iproc_i2c->msg; 545 uint32_t val; 546 547 /* Read valid data from RX FIFO */ 548 while (iproc_i2c->rx_bytes < msg->len) { 549 val = iproc_i2c_rd_reg(iproc_i2c, M_RX_OFFSET); 550 551 /* rx fifo empty */ 552 if (!((val >> M_RX_STATUS_SHIFT) & M_RX_STATUS_MASK)) 553 break; 554 555 msg->buf[iproc_i2c->rx_bytes] = 556 (val >> M_RX_DATA_SHIFT) & M_RX_DATA_MASK; 557 iproc_i2c->rx_bytes++; 558 } 559 } 560 561 static void bcm_iproc_i2c_send(struct bcm_iproc_i2c_dev *iproc_i2c) 562 { 563 struct i2c_msg *msg = iproc_i2c->msg; 564 unsigned int tx_bytes = msg->len - iproc_i2c->tx_bytes; 565 unsigned int i; 566 u32 val; 567 568 /* can only fill up to the FIFO size */ 569 tx_bytes = min_t(unsigned int, tx_bytes, M_TX_RX_FIFO_SIZE); 570 for (i = 0; i < tx_bytes; i++) { 571 /* start from where we left over */ 572 unsigned int idx = iproc_i2c->tx_bytes + i; 573 574 val = msg->buf[idx]; 575 576 /* mark the last byte */ 577 if (idx == msg->len - 1) { 578 val |= BIT(M_TX_WR_STATUS_SHIFT); 579 580 if (iproc_i2c->irq) { 581 u32 tmp; 582 583 /* 584 * Since this is the last byte, we should now 585 * disable TX FIFO underrun interrupt 586 */ 587 tmp = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); 588 tmp &= ~BIT(IE_M_TX_UNDERRUN_SHIFT); 589 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, 590 tmp); 591 } 592 } 593 594 /* load data into TX FIFO */ 595 iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val); 596 } 597 598 /* update number of transferred bytes */ 599 iproc_i2c->tx_bytes += tx_bytes; 600 } 601 602 static void bcm_iproc_i2c_read(struct bcm_iproc_i2c_dev *iproc_i2c) 603 { 604 struct i2c_msg *msg = iproc_i2c->msg; 605 u32 bytes_left, val; 606 607 bcm_iproc_i2c_read_valid_bytes(iproc_i2c); 608 bytes_left = msg->len - iproc_i2c->rx_bytes; 609 if (bytes_left == 0) { 610 if (iproc_i2c->irq) { 611 /* finished reading all data, disable rx thld event */ 612 val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); 613 val &= ~BIT(IS_M_RX_THLD_SHIFT); 614 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val); 615 } 616 } else if (bytes_left < iproc_i2c->thld_bytes) { 617 /* set bytes left as threshold */ 618 val = iproc_i2c_rd_reg(iproc_i2c, M_FIFO_CTRL_OFFSET); 619 val &= ~(M_FIFO_RX_THLD_MASK << M_FIFO_RX_THLD_SHIFT); 620 val |= (bytes_left << M_FIFO_RX_THLD_SHIFT); 621 iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val); 622 iproc_i2c->thld_bytes = bytes_left; 623 } 624 /* 625 * bytes_left >= iproc_i2c->thld_bytes, 626 * hence no need to change the THRESHOLD SET. 627 * It will remain as iproc_i2c->thld_bytes itself 628 */ 629 } 630 631 static void bcm_iproc_i2c_process_m_event(struct bcm_iproc_i2c_dev *iproc_i2c, 632 u32 status) 633 { 634 /* TX FIFO is empty and we have more data to send */ 635 if (status & BIT(IS_M_TX_UNDERRUN_SHIFT)) 636 bcm_iproc_i2c_send(iproc_i2c); 637 638 /* RX FIFO threshold is reached and data needs to be read out */ 639 if (status & BIT(IS_M_RX_THLD_SHIFT)) 640 bcm_iproc_i2c_read(iproc_i2c); 641 642 /* transfer is done */ 643 if (status & BIT(IS_M_START_BUSY_SHIFT)) { 644 iproc_i2c->xfer_is_done = 1; 645 if (iproc_i2c->irq) 646 complete(&iproc_i2c->done); 647 } 648 } 649 650 static irqreturn_t bcm_iproc_i2c_isr(int irq, void *data) 651 { 652 struct bcm_iproc_i2c_dev *iproc_i2c = data; 653 u32 slave_status; 654 u32 status; 655 bool ret; 656 657 status = iproc_i2c_rd_reg(iproc_i2c, IS_OFFSET); 658 /* process only slave interrupt which are enabled */ 659 slave_status = status & iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET) & 660 ISR_MASK_SLAVE; 661 662 if (slave_status) { 663 ret = bcm_iproc_i2c_slave_isr(iproc_i2c, slave_status); 664 if (ret) 665 return IRQ_HANDLED; 666 else 667 return IRQ_NONE; 668 } 669 670 status &= ISR_MASK; 671 if (!status) 672 return IRQ_NONE; 673 674 /* process all master based events */ 675 bcm_iproc_i2c_process_m_event(iproc_i2c, status); 676 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, status); 677 678 return IRQ_HANDLED; 679 } 680 681 static void bcm_iproc_i2c_init(struct bcm_iproc_i2c_dev *iproc_i2c) 682 { 683 u32 val; 684 685 /* put controller in reset */ 686 val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET); 687 val |= BIT(CFG_RESET_SHIFT); 688 val &= ~(BIT(CFG_EN_SHIFT)); 689 iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val); 690 691 /* wait 100 usec per spec */ 692 udelay(100); 693 694 /* bring controller out of reset */ 695 val &= ~(BIT(CFG_RESET_SHIFT)); 696 iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val); 697 698 /* flush TX/RX FIFOs and set RX FIFO threshold to zero */ 699 val = (BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT)); 700 iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val); 701 /* disable all interrupts */ 702 val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); 703 val &= ~(IE_M_ALL_INTERRUPT_MASK << 704 IE_M_ALL_INTERRUPT_SHIFT); 705 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val); 706 707 /* clear all pending interrupts */ 708 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, 0xffffffff); 709 } 710 711 static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c, 712 bool enable) 713 { 714 u32 val; 715 716 val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET); 717 if (enable) 718 val |= BIT(CFG_EN_SHIFT); 719 else 720 val &= ~BIT(CFG_EN_SHIFT); 721 iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val); 722 } 723 724 static int bcm_iproc_i2c_check_status(struct bcm_iproc_i2c_dev *iproc_i2c, 725 struct i2c_msg *msg) 726 { 727 u32 val; 728 729 val = iproc_i2c_rd_reg(iproc_i2c, M_CMD_OFFSET); 730 val = (val >> M_CMD_STATUS_SHIFT) & M_CMD_STATUS_MASK; 731 732 switch (val) { 733 case M_CMD_STATUS_SUCCESS: 734 return 0; 735 736 case M_CMD_STATUS_LOST_ARB: 737 dev_dbg(iproc_i2c->device, "lost bus arbitration\n"); 738 return -EAGAIN; 739 740 case M_CMD_STATUS_NACK_ADDR: 741 dev_dbg(iproc_i2c->device, "NAK addr:0x%02x\n", msg->addr); 742 return -ENXIO; 743 744 case M_CMD_STATUS_NACK_DATA: 745 dev_dbg(iproc_i2c->device, "NAK data\n"); 746 return -ENXIO; 747 748 case M_CMD_STATUS_TIMEOUT: 749 dev_dbg(iproc_i2c->device, "bus timeout\n"); 750 return -ETIMEDOUT; 751 752 case M_CMD_STATUS_FIFO_UNDERRUN: 753 dev_dbg(iproc_i2c->device, "FIFO under-run\n"); 754 return -ENXIO; 755 756 case M_CMD_STATUS_RX_FIFO_FULL: 757 dev_dbg(iproc_i2c->device, "RX FIFO full\n"); 758 return -ETIMEDOUT; 759 760 default: 761 dev_dbg(iproc_i2c->device, "unknown error code=%d\n", val); 762 763 /* re-initialize i2c for recovery */ 764 bcm_iproc_i2c_enable_disable(iproc_i2c, false); 765 bcm_iproc_i2c_init(iproc_i2c); 766 bcm_iproc_i2c_enable_disable(iproc_i2c, true); 767 768 return -EIO; 769 } 770 } 771 772 static int bcm_iproc_i2c_xfer_wait(struct bcm_iproc_i2c_dev *iproc_i2c, 773 struct i2c_msg *msg, 774 u32 cmd) 775 { 776 unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT_MSEC); 777 u32 val, status; 778 int ret; 779 780 iproc_i2c_wr_reg(iproc_i2c, M_CMD_OFFSET, cmd); 781 782 if (iproc_i2c->irq) { 783 time_left = wait_for_completion_timeout(&iproc_i2c->done, 784 time_left); 785 /* disable all interrupts */ 786 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, 0); 787 /* read it back to flush the write */ 788 iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); 789 /* make sure the interrupt handler isn't running */ 790 synchronize_irq(iproc_i2c->irq); 791 792 } else { /* polling mode */ 793 unsigned long timeout = jiffies + time_left; 794 795 do { 796 status = iproc_i2c_rd_reg(iproc_i2c, 797 IS_OFFSET) & ISR_MASK; 798 bcm_iproc_i2c_process_m_event(iproc_i2c, status); 799 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, status); 800 801 if (time_after(jiffies, timeout)) { 802 time_left = 0; 803 break; 804 } 805 806 cpu_relax(); 807 cond_resched(); 808 } while (!iproc_i2c->xfer_is_done); 809 } 810 811 if (!time_left && !iproc_i2c->xfer_is_done) { 812 /* flush both TX/RX FIFOs */ 813 val = BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT); 814 iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val); 815 return -ETIMEDOUT; 816 } 817 818 ret = bcm_iproc_i2c_check_status(iproc_i2c, msg); 819 if (ret) { 820 /* flush both TX/RX FIFOs */ 821 val = BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT); 822 iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val); 823 return ret; 824 } 825 826 return 0; 827 } 828 829 /* 830 * If 'process_call' is true, then this is a multi-msg transfer that requires 831 * a repeated start between the messages. 832 * More specifically, it must be a write (reg) followed by a read (data). 833 * The i2c quirks are set to enforce this rule. 834 */ 835 static int bcm_iproc_i2c_xfer_internal(struct bcm_iproc_i2c_dev *iproc_i2c, 836 struct i2c_msg *msgs, bool process_call) 837 { 838 int i; 839 u8 addr; 840 u32 val, tmp, val_intr_en; 841 unsigned int tx_bytes; 842 struct i2c_msg *msg = &msgs[0]; 843 844 /* check if bus is busy */ 845 if (!!(iproc_i2c_rd_reg(iproc_i2c, 846 M_CMD_OFFSET) & BIT(M_CMD_START_BUSY_SHIFT))) { 847 dev_warn(iproc_i2c->device, "bus is busy\n"); 848 return -EBUSY; 849 } 850 851 iproc_i2c->msg = msg; 852 853 /* format and load slave address into the TX FIFO */ 854 addr = i2c_8bit_addr_from_msg(msg); 855 iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, addr); 856 857 /* 858 * For a write transaction, load data into the TX FIFO. Only allow 859 * loading up to TX FIFO size - 1 bytes of data since the first byte 860 * has been used up by the slave address 861 */ 862 tx_bytes = min_t(unsigned int, msg->len, M_TX_RX_FIFO_SIZE - 1); 863 if (!(msg->flags & I2C_M_RD)) { 864 for (i = 0; i < tx_bytes; i++) { 865 val = msg->buf[i]; 866 867 /* mark the last byte */ 868 if (!process_call && (i == msg->len - 1)) 869 val |= BIT(M_TX_WR_STATUS_SHIFT); 870 871 iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val); 872 } 873 iproc_i2c->tx_bytes = tx_bytes; 874 } 875 876 /* Process the read message if this is process call */ 877 if (process_call) { 878 msg++; 879 iproc_i2c->msg = msg; /* point to second msg */ 880 881 /* 882 * The last byte to be sent out should be a slave 883 * address with read operation 884 */ 885 addr = i2c_8bit_addr_from_msg(msg); 886 /* mark it the last byte out */ 887 val = addr | BIT(M_TX_WR_STATUS_SHIFT); 888 iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val); 889 } 890 891 /* mark as incomplete before starting the transaction */ 892 if (iproc_i2c->irq) 893 reinit_completion(&iproc_i2c->done); 894 895 iproc_i2c->xfer_is_done = 0; 896 897 /* 898 * Enable the "start busy" interrupt, which will be triggered after the 899 * transaction is done, i.e., the internal start_busy bit, transitions 900 * from 1 to 0. 901 */ 902 val_intr_en = BIT(IE_M_START_BUSY_SHIFT); 903 904 /* 905 * If TX data size is larger than the TX FIFO, need to enable TX 906 * underrun interrupt, which will be triggerred when the TX FIFO is 907 * empty. When that happens we can then pump more data into the FIFO 908 */ 909 if (!process_call && !(msg->flags & I2C_M_RD) && 910 msg->len > iproc_i2c->tx_bytes) 911 val_intr_en |= BIT(IE_M_TX_UNDERRUN_SHIFT); 912 913 /* 914 * Now we can activate the transfer. For a read operation, specify the 915 * number of bytes to read 916 */ 917 val = BIT(M_CMD_START_BUSY_SHIFT); 918 919 if (msg->len == 0) { 920 /* SMBUS QUICK Command (Read/Write) */ 921 val |= (M_CMD_PROTOCOL_QUICK << M_CMD_PROTOCOL_SHIFT); 922 } else if (msg->flags & I2C_M_RD) { 923 u32 protocol; 924 925 iproc_i2c->rx_bytes = 0; 926 if (msg->len > M_RX_FIFO_MAX_THLD_VALUE) 927 iproc_i2c->thld_bytes = M_RX_FIFO_THLD_VALUE; 928 else 929 iproc_i2c->thld_bytes = msg->len; 930 931 /* set threshold value */ 932 tmp = iproc_i2c_rd_reg(iproc_i2c, M_FIFO_CTRL_OFFSET); 933 tmp &= ~(M_FIFO_RX_THLD_MASK << M_FIFO_RX_THLD_SHIFT); 934 tmp |= iproc_i2c->thld_bytes << M_FIFO_RX_THLD_SHIFT; 935 iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, tmp); 936 937 /* enable the RX threshold interrupt */ 938 val_intr_en |= BIT(IE_M_RX_THLD_SHIFT); 939 940 protocol = process_call ? 941 M_CMD_PROTOCOL_PROCESS : M_CMD_PROTOCOL_BLK_RD; 942 943 val |= (protocol << M_CMD_PROTOCOL_SHIFT) | 944 (msg->len << M_CMD_RD_CNT_SHIFT); 945 } else { 946 val |= (M_CMD_PROTOCOL_BLK_WR << M_CMD_PROTOCOL_SHIFT); 947 } 948 949 if (iproc_i2c->irq) 950 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val_intr_en); 951 952 return bcm_iproc_i2c_xfer_wait(iproc_i2c, msg, val); 953 } 954 955 static int bcm_iproc_i2c_xfer(struct i2c_adapter *adapter, 956 struct i2c_msg msgs[], int num) 957 { 958 struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(adapter); 959 bool process_call = false; 960 int ret; 961 962 if (num == 2) { 963 /* Repeated start, use process call */ 964 process_call = true; 965 if (msgs[1].flags & I2C_M_NOSTART) { 966 dev_err(iproc_i2c->device, "Invalid repeated start\n"); 967 return -EOPNOTSUPP; 968 } 969 } 970 971 ret = bcm_iproc_i2c_xfer_internal(iproc_i2c, msgs, process_call); 972 if (ret) { 973 dev_dbg(iproc_i2c->device, "xfer failed\n"); 974 return ret; 975 } 976 977 return num; 978 } 979 980 static uint32_t bcm_iproc_i2c_functionality(struct i2c_adapter *adap) 981 { 982 u32 val; 983 984 val = I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; 985 986 if (adap->algo->reg_slave) 987 val |= I2C_FUNC_SLAVE; 988 989 return val; 990 } 991 992 static struct i2c_algorithm bcm_iproc_algo = { 993 .master_xfer = bcm_iproc_i2c_xfer, 994 .functionality = bcm_iproc_i2c_functionality, 995 .reg_slave = bcm_iproc_i2c_reg_slave, 996 .unreg_slave = bcm_iproc_i2c_unreg_slave, 997 }; 998 999 static const struct i2c_adapter_quirks bcm_iproc_i2c_quirks = { 1000 .flags = I2C_AQ_COMB_WRITE_THEN_READ, 1001 .max_comb_1st_msg_len = M_TX_RX_FIFO_SIZE, 1002 .max_read_len = M_RX_MAX_READ_LEN, 1003 }; 1004 1005 static int bcm_iproc_i2c_cfg_speed(struct bcm_iproc_i2c_dev *iproc_i2c) 1006 { 1007 unsigned int bus_speed; 1008 u32 val; 1009 int ret = of_property_read_u32(iproc_i2c->device->of_node, 1010 "clock-frequency", &bus_speed); 1011 if (ret < 0) { 1012 dev_info(iproc_i2c->device, 1013 "unable to interpret clock-frequency DT property\n"); 1014 bus_speed = I2C_MAX_STANDARD_MODE_FREQ; 1015 } 1016 1017 if (bus_speed < I2C_MAX_STANDARD_MODE_FREQ) { 1018 dev_err(iproc_i2c->device, "%d Hz bus speed not supported\n", 1019 bus_speed); 1020 dev_err(iproc_i2c->device, 1021 "valid speeds are 100khz and 400khz\n"); 1022 return -EINVAL; 1023 } else if (bus_speed < I2C_MAX_FAST_MODE_FREQ) { 1024 bus_speed = I2C_MAX_STANDARD_MODE_FREQ; 1025 } else { 1026 bus_speed = I2C_MAX_FAST_MODE_FREQ; 1027 } 1028 1029 iproc_i2c->bus_speed = bus_speed; 1030 val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET); 1031 val &= ~BIT(TIM_CFG_MODE_400_SHIFT); 1032 val |= (bus_speed == I2C_MAX_FAST_MODE_FREQ) << TIM_CFG_MODE_400_SHIFT; 1033 iproc_i2c_wr_reg(iproc_i2c, TIM_CFG_OFFSET, val); 1034 1035 dev_info(iproc_i2c->device, "bus set to %u Hz\n", bus_speed); 1036 1037 return 0; 1038 } 1039 1040 static int bcm_iproc_i2c_probe(struct platform_device *pdev) 1041 { 1042 int irq, ret = 0; 1043 struct bcm_iproc_i2c_dev *iproc_i2c; 1044 struct i2c_adapter *adap; 1045 1046 iproc_i2c = devm_kzalloc(&pdev->dev, sizeof(*iproc_i2c), 1047 GFP_KERNEL); 1048 if (!iproc_i2c) 1049 return -ENOMEM; 1050 1051 platform_set_drvdata(pdev, iproc_i2c); 1052 iproc_i2c->device = &pdev->dev; 1053 iproc_i2c->type = 1054 (enum bcm_iproc_i2c_type)of_device_get_match_data(&pdev->dev); 1055 init_completion(&iproc_i2c->done); 1056 1057 iproc_i2c->base = devm_platform_ioremap_resource(pdev, 0); 1058 if (IS_ERR(iproc_i2c->base)) 1059 return PTR_ERR(iproc_i2c->base); 1060 1061 if (iproc_i2c->type == IPROC_I2C_NIC) { 1062 iproc_i2c->idm_base = devm_platform_ioremap_resource(pdev, 1); 1063 if (IS_ERR(iproc_i2c->idm_base)) 1064 return PTR_ERR(iproc_i2c->idm_base); 1065 1066 ret = of_property_read_u32(iproc_i2c->device->of_node, 1067 "brcm,ape-hsls-addr-mask", 1068 &iproc_i2c->ape_addr_mask); 1069 if (ret < 0) { 1070 dev_err(iproc_i2c->device, 1071 "'brcm,ape-hsls-addr-mask' missing\n"); 1072 return -EINVAL; 1073 } 1074 1075 spin_lock_init(&iproc_i2c->idm_lock); 1076 1077 /* no slave support */ 1078 bcm_iproc_algo.reg_slave = NULL; 1079 bcm_iproc_algo.unreg_slave = NULL; 1080 } 1081 1082 bcm_iproc_i2c_init(iproc_i2c); 1083 1084 ret = bcm_iproc_i2c_cfg_speed(iproc_i2c); 1085 if (ret) 1086 return ret; 1087 1088 irq = platform_get_irq(pdev, 0); 1089 if (irq > 0) { 1090 ret = devm_request_irq(iproc_i2c->device, irq, 1091 bcm_iproc_i2c_isr, 0, pdev->name, 1092 iproc_i2c); 1093 if (ret < 0) { 1094 dev_err(iproc_i2c->device, 1095 "unable to request irq %i\n", irq); 1096 return ret; 1097 } 1098 1099 iproc_i2c->irq = irq; 1100 } else { 1101 dev_warn(iproc_i2c->device, 1102 "no irq resource, falling back to poll mode\n"); 1103 } 1104 1105 bcm_iproc_i2c_enable_disable(iproc_i2c, true); 1106 1107 adap = &iproc_i2c->adapter; 1108 i2c_set_adapdata(adap, iproc_i2c); 1109 snprintf(adap->name, sizeof(adap->name), 1110 "Broadcom iProc (%s)", 1111 of_node_full_name(iproc_i2c->device->of_node)); 1112 adap->algo = &bcm_iproc_algo; 1113 adap->quirks = &bcm_iproc_i2c_quirks; 1114 adap->dev.parent = &pdev->dev; 1115 adap->dev.of_node = pdev->dev.of_node; 1116 1117 return i2c_add_adapter(adap); 1118 } 1119 1120 static void bcm_iproc_i2c_remove(struct platform_device *pdev) 1121 { 1122 struct bcm_iproc_i2c_dev *iproc_i2c = platform_get_drvdata(pdev); 1123 1124 if (iproc_i2c->irq) { 1125 /* 1126 * Make sure there's no pending interrupt when we remove the 1127 * adapter 1128 */ 1129 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, 0); 1130 iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); 1131 synchronize_irq(iproc_i2c->irq); 1132 } 1133 1134 i2c_del_adapter(&iproc_i2c->adapter); 1135 bcm_iproc_i2c_enable_disable(iproc_i2c, false); 1136 } 1137 1138 static int bcm_iproc_i2c_suspend(struct device *dev) 1139 { 1140 struct bcm_iproc_i2c_dev *iproc_i2c = dev_get_drvdata(dev); 1141 1142 if (iproc_i2c->irq) { 1143 /* 1144 * Make sure there's no pending interrupt when we go into 1145 * suspend 1146 */ 1147 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, 0); 1148 iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); 1149 synchronize_irq(iproc_i2c->irq); 1150 } 1151 1152 /* now disable the controller */ 1153 bcm_iproc_i2c_enable_disable(iproc_i2c, false); 1154 1155 return 0; 1156 } 1157 1158 static int bcm_iproc_i2c_resume(struct device *dev) 1159 { 1160 struct bcm_iproc_i2c_dev *iproc_i2c = dev_get_drvdata(dev); 1161 u32 val; 1162 1163 /* 1164 * Power domain could have been shut off completely in system deep 1165 * sleep, so re-initialize the block here 1166 */ 1167 bcm_iproc_i2c_init(iproc_i2c); 1168 1169 /* configure to the desired bus speed */ 1170 val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET); 1171 val &= ~BIT(TIM_CFG_MODE_400_SHIFT); 1172 val |= (iproc_i2c->bus_speed == I2C_MAX_FAST_MODE_FREQ) << TIM_CFG_MODE_400_SHIFT; 1173 iproc_i2c_wr_reg(iproc_i2c, TIM_CFG_OFFSET, val); 1174 1175 bcm_iproc_i2c_enable_disable(iproc_i2c, true); 1176 1177 return 0; 1178 } 1179 1180 static const struct dev_pm_ops bcm_iproc_i2c_pm_ops = { 1181 .suspend_late = &bcm_iproc_i2c_suspend, 1182 .resume_early = &bcm_iproc_i2c_resume 1183 }; 1184 1185 static int bcm_iproc_i2c_reg_slave(struct i2c_client *slave) 1186 { 1187 struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(slave->adapter); 1188 1189 if (iproc_i2c->slave) 1190 return -EBUSY; 1191 1192 if (slave->flags & I2C_CLIENT_TEN) 1193 return -EAFNOSUPPORT; 1194 1195 iproc_i2c->slave = slave; 1196 1197 tasklet_init(&iproc_i2c->slave_rx_tasklet, slave_rx_tasklet_fn, 1198 (unsigned long)iproc_i2c); 1199 1200 bcm_iproc_i2c_slave_init(iproc_i2c, false); 1201 return 0; 1202 } 1203 1204 static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave) 1205 { 1206 u32 tmp; 1207 struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(slave->adapter); 1208 1209 if (!iproc_i2c->slave) 1210 return -EINVAL; 1211 1212 disable_irq(iproc_i2c->irq); 1213 1214 tasklet_kill(&iproc_i2c->slave_rx_tasklet); 1215 1216 /* disable all slave interrupts */ 1217 tmp = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); 1218 tmp &= ~(IE_S_ALL_INTERRUPT_MASK << 1219 IE_S_ALL_INTERRUPT_SHIFT); 1220 iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, tmp); 1221 1222 /* Erase the slave address programmed */ 1223 tmp = iproc_i2c_rd_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET); 1224 tmp &= ~BIT(S_CFG_EN_NIC_SMB_ADDR3_SHIFT); 1225 iproc_i2c_wr_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET, tmp); 1226 1227 /* flush TX/RX FIFOs */ 1228 tmp = (BIT(S_FIFO_RX_FLUSH_SHIFT) | BIT(S_FIFO_TX_FLUSH_SHIFT)); 1229 iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, tmp); 1230 1231 /* clear all pending slave interrupts */ 1232 iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, ISR_MASK_SLAVE); 1233 1234 iproc_i2c->slave = NULL; 1235 1236 enable_irq(iproc_i2c->irq); 1237 1238 return 0; 1239 } 1240 1241 static const struct of_device_id bcm_iproc_i2c_of_match[] = { 1242 { 1243 .compatible = "brcm,iproc-i2c", 1244 .data = (int *)IPROC_I2C, 1245 }, { 1246 .compatible = "brcm,iproc-nic-i2c", 1247 .data = (int *)IPROC_I2C_NIC, 1248 }, 1249 { /* sentinel */ } 1250 }; 1251 MODULE_DEVICE_TABLE(of, bcm_iproc_i2c_of_match); 1252 1253 static struct platform_driver bcm_iproc_i2c_driver = { 1254 .driver = { 1255 .name = "bcm-iproc-i2c", 1256 .of_match_table = bcm_iproc_i2c_of_match, 1257 .pm = pm_sleep_ptr(&bcm_iproc_i2c_pm_ops), 1258 }, 1259 .probe = bcm_iproc_i2c_probe, 1260 .remove = bcm_iproc_i2c_remove, 1261 }; 1262 module_platform_driver(bcm_iproc_i2c_driver); 1263 1264 MODULE_AUTHOR("Ray Jui <rjui@broadcom.com>"); 1265 MODULE_DESCRIPTION("Broadcom iProc I2C Driver"); 1266 MODULE_LICENSE("GPL v2"); 1267