1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * i2c_adap_pxa.c 4 * 5 * I2C adapter for the PXA I2C bus access. 6 * 7 * Copyright (C) 2002 Intrinsyc Software Inc. 8 * Copyright (C) 2004-2005 Deep Blue Solutions Ltd. 9 * 10 * History: 11 * Apr 2002: Initial version [CS] 12 * Jun 2002: Properly separated algo/adap [FB] 13 * Jan 2003: Fixed several bugs concerning interrupt handling [Kai-Uwe Bloem] 14 * Jan 2003: added limited signal handling [Kai-Uwe Bloem] 15 * Sep 2004: Major rework to ensure efficient bus handling [RMK] 16 * Dec 2004: Added support for PXA27x and slave device probing [Liam Girdwood] 17 * Feb 2005: Rework slave mode handling [RMK] 18 */ 19 #include <linux/clk.h> 20 #include <linux/delay.h> 21 #include <linux/err.h> 22 #include <linux/errno.h> 23 #include <linux/gpio/consumer.h> 24 #include <linux/i2c.h> 25 #include <linux/init.h> 26 #include <linux/interrupt.h> 27 #include <linux/io.h> 28 #include <linux/kernel.h> 29 #include <linux/module.h> 30 #include <linux/of.h> 31 #include <linux/of_device.h> 32 #include <linux/pinctrl/consumer.h> 33 #include <linux/platform_device.h> 34 #include <linux/platform_data/i2c-pxa.h> 35 #include <linux/slab.h> 36 37 /* I2C register field definitions */ 38 #define IBMR_SDAS (1 << 0) 39 #define IBMR_SCLS (1 << 1) 40 41 #define ICR_START (1 << 0) /* start bit */ 42 #define ICR_STOP (1 << 1) /* stop bit */ 43 #define ICR_ACKNAK (1 << 2) /* send ACK(0) or NAK(1) */ 44 #define ICR_TB (1 << 3) /* transfer byte bit */ 45 #define ICR_MA (1 << 4) /* master abort */ 46 #define ICR_SCLE (1 << 5) /* master clock enable */ 47 #define ICR_IUE (1 << 6) /* unit enable */ 48 #define ICR_GCD (1 << 7) /* general call disable */ 49 #define ICR_ITEIE (1 << 8) /* enable tx interrupts */ 50 #define ICR_IRFIE (1 << 9) /* enable rx interrupts */ 51 #define ICR_BEIE (1 << 10) /* enable bus error ints */ 52 #define ICR_SSDIE (1 << 11) /* slave STOP detected int enable */ 53 #define ICR_ALDIE (1 << 12) /* enable arbitration interrupt */ 54 #define ICR_SADIE (1 << 13) /* slave address detected int enable */ 55 #define ICR_UR (1 << 14) /* unit reset */ 56 #define ICR_FM (1 << 15) /* fast mode */ 57 #define ICR_HS (1 << 16) /* High Speed mode */ 58 #define ICR_A3700_FM (1 << 16) /* fast mode for armada-3700 */ 59 #define ICR_A3700_HS (1 << 17) /* high speed mode for armada-3700 */ 60 #define ICR_GPIOEN (1 << 19) /* enable GPIO mode for SCL in HS */ 61 62 #define ISR_RWM (1 << 0) /* read/write mode */ 63 #define ISR_ACKNAK (1 << 1) /* ack/nak status */ 64 #define ISR_UB (1 << 2) /* unit busy */ 65 #define ISR_IBB (1 << 3) /* bus busy */ 66 #define ISR_SSD (1 << 4) /* slave stop detected */ 67 #define ISR_ALD (1 << 5) /* arbitration loss detected */ 68 #define ISR_ITE (1 << 6) /* tx buffer empty */ 69 #define ISR_IRF (1 << 7) /* rx buffer full */ 70 #define ISR_GCAD (1 << 8) /* general call address detected */ 71 #define ISR_SAD (1 << 9) /* slave address detected */ 72 #define ISR_BED (1 << 10) /* bus error no ACK/NAK */ 73 74 #define ILCR_SLV_SHIFT 0 75 #define ILCR_SLV_MASK (0x1FF << ILCR_SLV_SHIFT) 76 #define ILCR_FLV_SHIFT 9 77 #define ILCR_FLV_MASK (0x1FF << ILCR_FLV_SHIFT) 78 #define ILCR_HLVL_SHIFT 18 79 #define ILCR_HLVL_MASK (0x1FF << ILCR_HLVL_SHIFT) 80 #define ILCR_HLVH_SHIFT 27 81 #define ILCR_HLVH_MASK (0x1F << ILCR_HLVH_SHIFT) 82 83 #define IWCR_CNT_SHIFT 0 84 #define IWCR_CNT_MASK (0x1F << IWCR_CNT_SHIFT) 85 #define IWCR_HS_CNT1_SHIFT 5 86 #define IWCR_HS_CNT1_MASK (0x1F << IWCR_HS_CNT1_SHIFT) 87 #define IWCR_HS_CNT2_SHIFT 10 88 #define IWCR_HS_CNT2_MASK (0x1F << IWCR_HS_CNT2_SHIFT) 89 90 /* need a longer timeout if we're dealing with the fact we may well be 91 * looking at a multi-master environment 92 */ 93 #define DEF_TIMEOUT 32 94 95 #define NO_SLAVE (-ENXIO) 96 #define BUS_ERROR (-EREMOTEIO) 97 #define XFER_NAKED (-ECONNREFUSED) 98 #define I2C_RETRY (-2000) /* an error has occurred retry transmit */ 99 100 /* ICR initialize bit values 101 * 102 * 15 FM 0 (100 kHz operation) 103 * 14 UR 0 (No unit reset) 104 * 13 SADIE 0 (Disables the unit from interrupting on slave addresses 105 * matching its slave address) 106 * 12 ALDIE 0 (Disables the unit from interrupt when it loses arbitration 107 * in master mode) 108 * 11 SSDIE 0 (Disables interrupts from a slave stop detected, in slave mode) 109 * 10 BEIE 1 (Enable interrupts from detected bus errors, no ACK sent) 110 * 9 IRFIE 1 (Enable interrupts from full buffer received) 111 * 8 ITEIE 1 (Enables the I2C unit to interrupt when transmit buffer empty) 112 * 7 GCD 1 (Disables i2c unit response to general call messages as a slave) 113 * 6 IUE 0 (Disable unit until we change settings) 114 * 5 SCLE 1 (Enables the i2c clock output for master mode (drives SCL) 115 * 4 MA 0 (Only send stop with the ICR stop bit) 116 * 3 TB 0 (We are not transmitting a byte initially) 117 * 2 ACKNAK 0 (Send an ACK after the unit receives a byte) 118 * 1 STOP 0 (Do not send a STOP) 119 * 0 START 0 (Do not send a START) 120 */ 121 #define I2C_ICR_INIT (ICR_BEIE | ICR_IRFIE | ICR_ITEIE | ICR_GCD | ICR_SCLE) 122 123 /* I2C status register init values 124 * 125 * 10 BED 1 (Clear bus error detected) 126 * 9 SAD 1 (Clear slave address detected) 127 * 7 IRF 1 (Clear IDBR Receive Full) 128 * 6 ITE 1 (Clear IDBR Transmit Empty) 129 * 5 ALD 1 (Clear Arbitration Loss Detected) 130 * 4 SSD 1 (Clear Slave Stop Detected) 131 */ 132 #define I2C_ISR_INIT 0x7FF /* status register init */ 133 134 struct pxa_reg_layout { 135 u32 ibmr; 136 u32 idbr; 137 u32 icr; 138 u32 isr; 139 u32 isar; 140 u32 ilcr; 141 u32 iwcr; 142 u32 fm; 143 u32 hs; 144 }; 145 146 enum pxa_i2c_types { 147 REGS_PXA2XX, 148 REGS_PXA3XX, 149 REGS_CE4100, 150 REGS_PXA910, 151 REGS_A3700, 152 }; 153 154 /* I2C register layout definitions */ 155 static struct pxa_reg_layout pxa_reg_layout[] = { 156 [REGS_PXA2XX] = { 157 .ibmr = 0x00, 158 .idbr = 0x08, 159 .icr = 0x10, 160 .isr = 0x18, 161 .isar = 0x20, 162 .fm = ICR_FM, 163 .hs = ICR_HS, 164 }, 165 [REGS_PXA3XX] = { 166 .ibmr = 0x00, 167 .idbr = 0x04, 168 .icr = 0x08, 169 .isr = 0x0c, 170 .isar = 0x10, 171 .fm = ICR_FM, 172 .hs = ICR_HS, 173 }, 174 [REGS_CE4100] = { 175 .ibmr = 0x14, 176 .idbr = 0x0c, 177 .icr = 0x00, 178 .isr = 0x04, 179 /* no isar register */ 180 .fm = ICR_FM, 181 .hs = ICR_HS, 182 }, 183 [REGS_PXA910] = { 184 .ibmr = 0x00, 185 .idbr = 0x08, 186 .icr = 0x10, 187 .isr = 0x18, 188 .isar = 0x20, 189 .ilcr = 0x28, 190 .iwcr = 0x30, 191 .fm = ICR_FM, 192 .hs = ICR_HS, 193 }, 194 [REGS_A3700] = { 195 .ibmr = 0x00, 196 .idbr = 0x04, 197 .icr = 0x08, 198 .isr = 0x0c, 199 .isar = 0x10, 200 .fm = ICR_A3700_FM, 201 .hs = ICR_A3700_HS, 202 }, 203 }; 204 205 static const struct of_device_id i2c_pxa_dt_ids[] = { 206 { .compatible = "mrvl,pxa-i2c", .data = (void *)REGS_PXA2XX }, 207 { .compatible = "mrvl,pwri2c", .data = (void *)REGS_PXA3XX }, 208 { .compatible = "mrvl,mmp-twsi", .data = (void *)REGS_PXA910 }, 209 { .compatible = "marvell,armada-3700-i2c", .data = (void *)REGS_A3700 }, 210 {} 211 }; 212 MODULE_DEVICE_TABLE(of, i2c_pxa_dt_ids); 213 214 static const struct platform_device_id i2c_pxa_id_table[] = { 215 { "pxa2xx-i2c", REGS_PXA2XX }, 216 { "pxa3xx-pwri2c", REGS_PXA3XX }, 217 { "ce4100-i2c", REGS_CE4100 }, 218 { "pxa910-i2c", REGS_PXA910 }, 219 { "armada-3700-i2c", REGS_A3700 }, 220 { }, 221 }; 222 MODULE_DEVICE_TABLE(platform, i2c_pxa_id_table); 223 224 struct pxa_i2c { 225 spinlock_t lock; 226 wait_queue_head_t wait; 227 struct i2c_msg *msg; 228 unsigned int msg_num; 229 unsigned int msg_idx; 230 unsigned int msg_ptr; 231 unsigned int slave_addr; 232 unsigned int req_slave_addr; 233 234 struct i2c_adapter adap; 235 struct clk *clk; 236 #ifdef CONFIG_I2C_PXA_SLAVE 237 struct i2c_client *slave; 238 #endif 239 240 unsigned int irqlogidx; 241 u32 isrlog[32]; 242 u32 icrlog[32]; 243 244 void __iomem *reg_base; 245 void __iomem *reg_ibmr; 246 void __iomem *reg_idbr; 247 void __iomem *reg_icr; 248 void __iomem *reg_isr; 249 void __iomem *reg_isar; 250 void __iomem *reg_ilcr; 251 void __iomem *reg_iwcr; 252 253 unsigned long iobase; 254 unsigned long iosize; 255 256 int irq; 257 unsigned int use_pio :1; 258 unsigned int fast_mode :1; 259 unsigned int high_mode:1; 260 unsigned char master_code; 261 unsigned long rate; 262 bool highmode_enter; 263 u32 fm_mask; 264 u32 hs_mask; 265 266 struct i2c_bus_recovery_info recovery; 267 }; 268 269 #define _IBMR(i2c) ((i2c)->reg_ibmr) 270 #define _IDBR(i2c) ((i2c)->reg_idbr) 271 #define _ICR(i2c) ((i2c)->reg_icr) 272 #define _ISR(i2c) ((i2c)->reg_isr) 273 #define _ISAR(i2c) ((i2c)->reg_isar) 274 #define _ILCR(i2c) ((i2c)->reg_ilcr) 275 #define _IWCR(i2c) ((i2c)->reg_iwcr) 276 277 /* 278 * I2C Slave mode address 279 */ 280 #define I2C_PXA_SLAVE_ADDR 0x1 281 282 #ifdef DEBUG 283 284 struct bits { 285 u32 mask; 286 const char *set; 287 const char *unset; 288 }; 289 #define PXA_BIT(m, s, u) { .mask = m, .set = s, .unset = u } 290 291 static inline void 292 decode_bits(const char *prefix, const struct bits *bits, int num, u32 val) 293 { 294 printk("%s %08x:", prefix, val); 295 while (num--) { 296 const char *str = val & bits->mask ? bits->set : bits->unset; 297 if (str) 298 pr_cont(" %s", str); 299 bits++; 300 } 301 pr_cont("\n"); 302 } 303 304 static const struct bits isr_bits[] = { 305 PXA_BIT(ISR_RWM, "RX", "TX"), 306 PXA_BIT(ISR_ACKNAK, "NAK", "ACK"), 307 PXA_BIT(ISR_UB, "Bsy", "Rdy"), 308 PXA_BIT(ISR_IBB, "BusBsy", "BusRdy"), 309 PXA_BIT(ISR_SSD, "SlaveStop", NULL), 310 PXA_BIT(ISR_ALD, "ALD", NULL), 311 PXA_BIT(ISR_ITE, "TxEmpty", NULL), 312 PXA_BIT(ISR_IRF, "RxFull", NULL), 313 PXA_BIT(ISR_GCAD, "GenCall", NULL), 314 PXA_BIT(ISR_SAD, "SlaveAddr", NULL), 315 PXA_BIT(ISR_BED, "BusErr", NULL), 316 }; 317 318 static void decode_ISR(unsigned int val) 319 { 320 decode_bits(KERN_DEBUG "ISR", isr_bits, ARRAY_SIZE(isr_bits), val); 321 } 322 323 static const struct bits icr_bits[] = { 324 PXA_BIT(ICR_START, "START", NULL), 325 PXA_BIT(ICR_STOP, "STOP", NULL), 326 PXA_BIT(ICR_ACKNAK, "ACKNAK", NULL), 327 PXA_BIT(ICR_TB, "TB", NULL), 328 PXA_BIT(ICR_MA, "MA", NULL), 329 PXA_BIT(ICR_SCLE, "SCLE", "scle"), 330 PXA_BIT(ICR_IUE, "IUE", "iue"), 331 PXA_BIT(ICR_GCD, "GCD", NULL), 332 PXA_BIT(ICR_ITEIE, "ITEIE", NULL), 333 PXA_BIT(ICR_IRFIE, "IRFIE", NULL), 334 PXA_BIT(ICR_BEIE, "BEIE", NULL), 335 PXA_BIT(ICR_SSDIE, "SSDIE", NULL), 336 PXA_BIT(ICR_ALDIE, "ALDIE", NULL), 337 PXA_BIT(ICR_SADIE, "SADIE", NULL), 338 PXA_BIT(ICR_UR, "UR", "ur"), 339 }; 340 341 #ifdef CONFIG_I2C_PXA_SLAVE 342 static void decode_ICR(unsigned int val) 343 { 344 decode_bits(KERN_DEBUG "ICR", icr_bits, ARRAY_SIZE(icr_bits), val); 345 } 346 #endif 347 348 static unsigned int i2c_debug = DEBUG; 349 350 static void i2c_pxa_show_state(struct pxa_i2c *i2c, int lno, const char *fname) 351 { 352 dev_dbg(&i2c->adap.dev, "state:%s:%d: ISR=%08x, ICR=%08x, IBMR=%02x\n", fname, lno, 353 readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c))); 354 } 355 356 #define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __func__) 357 358 static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why) 359 { 360 unsigned int i; 361 struct device *dev = &i2c->adap.dev; 362 363 dev_err(dev, "slave_0x%x error: %s\n", 364 i2c->req_slave_addr >> 1, why); 365 dev_err(dev, "msg_num: %d msg_idx: %d msg_ptr: %d\n", 366 i2c->msg_num, i2c->msg_idx, i2c->msg_ptr); 367 dev_err(dev, "IBMR: %08x IDBR: %08x ICR: %08x ISR: %08x\n", 368 readl(_IBMR(i2c)), readl(_IDBR(i2c)), readl(_ICR(i2c)), 369 readl(_ISR(i2c))); 370 dev_err(dev, "log:"); 371 for (i = 0; i < i2c->irqlogidx; i++) 372 pr_cont(" [%03x:%05x]", i2c->isrlog[i], i2c->icrlog[i]); 373 pr_cont("\n"); 374 } 375 376 #else /* ifdef DEBUG */ 377 378 #define i2c_debug 0 379 380 #define show_state(i2c) do { } while (0) 381 #define decode_ISR(val) do { } while (0) 382 #define decode_ICR(val) do { } while (0) 383 #define i2c_pxa_scream_blue_murder(i2c, why) do { } while (0) 384 385 #endif /* ifdef DEBUG / else */ 386 387 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret); 388 389 static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c) 390 { 391 return !(readl(_ICR(i2c)) & ICR_SCLE); 392 } 393 394 static void i2c_pxa_abort(struct pxa_i2c *i2c) 395 { 396 int i = 250; 397 398 if (i2c_pxa_is_slavemode(i2c)) { 399 dev_dbg(&i2c->adap.dev, "%s: called in slave mode\n", __func__); 400 return; 401 } 402 403 while ((i > 0) && (readl(_IBMR(i2c)) & IBMR_SDAS) == 0) { 404 unsigned long icr = readl(_ICR(i2c)); 405 406 icr &= ~ICR_START; 407 icr |= ICR_ACKNAK | ICR_STOP | ICR_TB; 408 409 writel(icr, _ICR(i2c)); 410 411 show_state(i2c); 412 413 mdelay(1); 414 i --; 415 } 416 417 writel(readl(_ICR(i2c)) & ~(ICR_MA | ICR_START | ICR_STOP), 418 _ICR(i2c)); 419 } 420 421 static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c) 422 { 423 int timeout = DEF_TIMEOUT; 424 u32 isr; 425 426 while (1) { 427 isr = readl(_ISR(i2c)); 428 if (!(isr & (ISR_IBB | ISR_UB))) 429 return 0; 430 431 if (isr & ISR_SAD) 432 timeout += 4; 433 434 if (!timeout--) 435 break; 436 437 msleep(2); 438 show_state(i2c); 439 } 440 441 show_state(i2c); 442 443 return I2C_RETRY; 444 } 445 446 static int i2c_pxa_wait_master(struct pxa_i2c *i2c) 447 { 448 unsigned long timeout = jiffies + HZ*4; 449 450 while (time_before(jiffies, timeout)) { 451 if (i2c_debug > 1) 452 dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n", 453 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c))); 454 455 if (readl(_ISR(i2c)) & ISR_SAD) { 456 if (i2c_debug > 0) 457 dev_dbg(&i2c->adap.dev, "%s: Slave detected\n", __func__); 458 goto out; 459 } 460 461 /* wait for unit and bus being not busy, and we also do a 462 * quick check of the i2c lines themselves to ensure they've 463 * gone high... 464 */ 465 if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) == 0 && 466 readl(_IBMR(i2c)) == (IBMR_SCLS | IBMR_SDAS)) { 467 if (i2c_debug > 0) 468 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__); 469 return 1; 470 } 471 472 msleep(1); 473 } 474 475 if (i2c_debug > 0) 476 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__); 477 out: 478 return 0; 479 } 480 481 static int i2c_pxa_set_master(struct pxa_i2c *i2c) 482 { 483 if (i2c_debug) 484 dev_dbg(&i2c->adap.dev, "setting to bus master\n"); 485 486 if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) != 0) { 487 dev_dbg(&i2c->adap.dev, "%s: unit is busy\n", __func__); 488 if (!i2c_pxa_wait_master(i2c)) { 489 dev_dbg(&i2c->adap.dev, "%s: error: unit busy\n", __func__); 490 return I2C_RETRY; 491 } 492 } 493 494 writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c)); 495 return 0; 496 } 497 498 #ifdef CONFIG_I2C_PXA_SLAVE 499 static int i2c_pxa_wait_slave(struct pxa_i2c *i2c) 500 { 501 unsigned long timeout = jiffies + HZ*1; 502 503 /* wait for stop */ 504 505 show_state(i2c); 506 507 while (time_before(jiffies, timeout)) { 508 if (i2c_debug > 1) 509 dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n", 510 __func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c))); 511 512 if ((readl(_ISR(i2c)) & (ISR_UB|ISR_IBB)) == 0 || 513 (readl(_ISR(i2c)) & ISR_SAD) != 0 || 514 (readl(_ICR(i2c)) & ICR_SCLE) == 0) { 515 if (i2c_debug > 1) 516 dev_dbg(&i2c->adap.dev, "%s: done\n", __func__); 517 return 1; 518 } 519 520 msleep(1); 521 } 522 523 if (i2c_debug > 0) 524 dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__); 525 return 0; 526 } 527 528 /* 529 * clear the hold on the bus, and take of anything else 530 * that has been configured 531 */ 532 static void i2c_pxa_set_slave(struct pxa_i2c *i2c, int errcode) 533 { 534 show_state(i2c); 535 536 if (errcode < 0) { 537 udelay(100); /* simple delay */ 538 } else { 539 /* we need to wait for the stop condition to end */ 540 541 /* if we where in stop, then clear... */ 542 if (readl(_ICR(i2c)) & ICR_STOP) { 543 udelay(100); 544 writel(readl(_ICR(i2c)) & ~ICR_STOP, _ICR(i2c)); 545 } 546 547 if (!i2c_pxa_wait_slave(i2c)) { 548 dev_err(&i2c->adap.dev, "%s: wait timedout\n", 549 __func__); 550 return; 551 } 552 } 553 554 writel(readl(_ICR(i2c)) & ~(ICR_STOP|ICR_ACKNAK|ICR_MA), _ICR(i2c)); 555 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c)); 556 557 if (i2c_debug) { 558 dev_dbg(&i2c->adap.dev, "ICR now %08x, ISR %08x\n", readl(_ICR(i2c)), readl(_ISR(i2c))); 559 decode_ICR(readl(_ICR(i2c))); 560 } 561 } 562 #else 563 #define i2c_pxa_set_slave(i2c, err) do { } while (0) 564 #endif 565 566 static void i2c_pxa_do_reset(struct pxa_i2c *i2c) 567 { 568 /* reset according to 9.8 */ 569 writel(ICR_UR, _ICR(i2c)); 570 writel(I2C_ISR_INIT, _ISR(i2c)); 571 writel(readl(_ICR(i2c)) & ~ICR_UR, _ICR(i2c)); 572 573 if (i2c->reg_isar && IS_ENABLED(CONFIG_I2C_PXA_SLAVE)) 574 writel(i2c->slave_addr, _ISAR(i2c)); 575 576 /* set control register values */ 577 writel(I2C_ICR_INIT | (i2c->fast_mode ? i2c->fm_mask : 0), _ICR(i2c)); 578 writel(readl(_ICR(i2c)) | (i2c->high_mode ? i2c->hs_mask : 0), _ICR(i2c)); 579 580 #ifdef CONFIG_I2C_PXA_SLAVE 581 dev_info(&i2c->adap.dev, "Enabling slave mode\n"); 582 writel(readl(_ICR(i2c)) | ICR_SADIE | ICR_ALDIE | ICR_SSDIE, _ICR(i2c)); 583 #endif 584 585 i2c_pxa_set_slave(i2c, 0); 586 } 587 588 static void i2c_pxa_enable(struct pxa_i2c *i2c) 589 { 590 /* enable unit */ 591 writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c)); 592 udelay(100); 593 } 594 595 static void i2c_pxa_reset(struct pxa_i2c *i2c) 596 { 597 pr_debug("Resetting I2C Controller Unit\n"); 598 599 /* abort any transfer currently under way */ 600 i2c_pxa_abort(i2c); 601 i2c_pxa_do_reset(i2c); 602 i2c_pxa_enable(i2c); 603 } 604 605 606 #ifdef CONFIG_I2C_PXA_SLAVE 607 /* 608 * PXA I2C Slave mode 609 */ 610 611 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr) 612 { 613 if (isr & ISR_BED) { 614 /* what should we do here? */ 615 } else { 616 u8 byte = 0; 617 618 if (i2c->slave != NULL) 619 i2c_slave_event(i2c->slave, I2C_SLAVE_READ_PROCESSED, 620 &byte); 621 622 writel(byte, _IDBR(i2c)); 623 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c)); /* allow next byte */ 624 } 625 } 626 627 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr) 628 { 629 u8 byte = readl(_IDBR(i2c)); 630 631 if (i2c->slave != NULL) 632 i2c_slave_event(i2c->slave, I2C_SLAVE_WRITE_RECEIVED, &byte); 633 634 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c)); 635 } 636 637 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr) 638 { 639 int timeout; 640 641 if (i2c_debug > 0) 642 dev_dbg(&i2c->adap.dev, "SAD, mode is slave-%cx\n", 643 (isr & ISR_RWM) ? 'r' : 't'); 644 645 if (i2c->slave != NULL) { 646 if (isr & ISR_RWM) { 647 u8 byte = 0; 648 649 i2c_slave_event(i2c->slave, I2C_SLAVE_READ_REQUESTED, 650 &byte); 651 writel(byte, _IDBR(i2c)); 652 } else { 653 i2c_slave_event(i2c->slave, I2C_SLAVE_WRITE_REQUESTED, 654 NULL); 655 } 656 } 657 658 /* 659 * slave could interrupt in the middle of us generating a 660 * start condition... if this happens, we'd better back off 661 * and stop holding the poor thing up 662 */ 663 writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c)); 664 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c)); 665 666 timeout = 0x10000; 667 668 while (1) { 669 if ((readl(_IBMR(i2c)) & IBMR_SCLS) == IBMR_SCLS) 670 break; 671 672 timeout--; 673 674 if (timeout <= 0) { 675 dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n"); 676 break; 677 } 678 } 679 680 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c)); 681 } 682 683 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c) 684 { 685 if (i2c_debug > 2) 686 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop)\n"); 687 688 if (i2c->slave != NULL) 689 i2c_slave_event(i2c->slave, I2C_SLAVE_STOP, NULL); 690 691 if (i2c_debug > 2) 692 dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop) acked\n"); 693 694 /* 695 * If we have a master-mode message waiting, 696 * kick it off now that the slave has completed. 697 */ 698 if (i2c->msg) 699 i2c_pxa_master_complete(i2c, I2C_RETRY); 700 } 701 702 static int i2c_pxa_slave_reg(struct i2c_client *slave) 703 { 704 struct pxa_i2c *i2c = slave->adapter->algo_data; 705 706 if (i2c->slave) 707 return -EBUSY; 708 709 if (!i2c->reg_isar) 710 return -EAFNOSUPPORT; 711 712 i2c->slave = slave; 713 i2c->slave_addr = slave->addr; 714 715 writel(i2c->slave_addr, _ISAR(i2c)); 716 717 return 0; 718 } 719 720 static int i2c_pxa_slave_unreg(struct i2c_client *slave) 721 { 722 struct pxa_i2c *i2c = slave->adapter->algo_data; 723 724 WARN_ON(!i2c->slave); 725 726 i2c->slave_addr = I2C_PXA_SLAVE_ADDR; 727 writel(i2c->slave_addr, _ISAR(i2c)); 728 729 i2c->slave = NULL; 730 731 return 0; 732 } 733 #else 734 static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr) 735 { 736 if (isr & ISR_BED) { 737 /* what should we do here? */ 738 } else { 739 writel(0, _IDBR(i2c)); 740 writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c)); 741 } 742 } 743 744 static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr) 745 { 746 writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c)); 747 } 748 749 static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr) 750 { 751 int timeout; 752 753 /* 754 * slave could interrupt in the middle of us generating a 755 * start condition... if this happens, we'd better back off 756 * and stop holding the poor thing up 757 */ 758 writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c)); 759 writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c)); 760 761 timeout = 0x10000; 762 763 while (1) { 764 if ((readl(_IBMR(i2c)) & IBMR_SCLS) == IBMR_SCLS) 765 break; 766 767 timeout--; 768 769 if (timeout <= 0) { 770 dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n"); 771 break; 772 } 773 } 774 775 writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c)); 776 } 777 778 static void i2c_pxa_slave_stop(struct pxa_i2c *i2c) 779 { 780 if (i2c->msg) 781 i2c_pxa_master_complete(i2c, I2C_RETRY); 782 } 783 #endif 784 785 /* 786 * PXA I2C Master mode 787 */ 788 789 static inline void i2c_pxa_start_message(struct pxa_i2c *i2c) 790 { 791 u32 icr; 792 793 /* 794 * Step 1: target slave address into IDBR 795 */ 796 i2c->req_slave_addr = i2c_8bit_addr_from_msg(i2c->msg); 797 writel(i2c->req_slave_addr, _IDBR(i2c)); 798 799 /* 800 * Step 2: initiate the write. 801 */ 802 icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE); 803 writel(icr | ICR_START | ICR_TB, _ICR(i2c)); 804 } 805 806 static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c) 807 { 808 u32 icr; 809 810 /* Clear the START, STOP, ACK, TB and MA flags */ 811 icr = readl(_ICR(i2c)); 812 icr &= ~(ICR_START | ICR_STOP | ICR_ACKNAK | ICR_TB | ICR_MA); 813 writel(icr, _ICR(i2c)); 814 } 815 816 /* 817 * PXA I2C send master code 818 * 1. Load master code to IDBR and send it. 819 * Note for HS mode, set ICR [GPIOEN]. 820 * 2. Wait until win arbitration. 821 */ 822 static int i2c_pxa_send_mastercode(struct pxa_i2c *i2c) 823 { 824 u32 icr; 825 long timeout; 826 827 spin_lock_irq(&i2c->lock); 828 i2c->highmode_enter = true; 829 writel(i2c->master_code, _IDBR(i2c)); 830 831 icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE); 832 icr |= ICR_GPIOEN | ICR_START | ICR_TB | ICR_ITEIE; 833 writel(icr, _ICR(i2c)); 834 835 spin_unlock_irq(&i2c->lock); 836 timeout = wait_event_timeout(i2c->wait, 837 i2c->highmode_enter == false, HZ * 1); 838 839 i2c->highmode_enter = false; 840 841 return (timeout == 0) ? I2C_RETRY : 0; 842 } 843 844 /* 845 * i2c_pxa_master_complete - complete the message and wake up. 846 */ 847 static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret) 848 { 849 i2c->msg_ptr = 0; 850 i2c->msg = NULL; 851 i2c->msg_idx ++; 852 i2c->msg_num = 0; 853 if (ret) 854 i2c->msg_idx = ret; 855 if (!i2c->use_pio) 856 wake_up(&i2c->wait); 857 } 858 859 static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr) 860 { 861 u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB); 862 863 again: 864 /* 865 * If ISR_ALD is set, we lost arbitration. 866 */ 867 if (isr & ISR_ALD) { 868 /* 869 * Do we need to do anything here? The PXA docs 870 * are vague about what happens. 871 */ 872 i2c_pxa_scream_blue_murder(i2c, "ALD set"); 873 874 /* 875 * We ignore this error. We seem to see spurious ALDs 876 * for seemingly no reason. If we handle them as I think 877 * they should, we end up causing an I2C error, which 878 * is painful for some systems. 879 */ 880 return; /* ignore */ 881 } 882 883 if ((isr & ISR_BED) && 884 (!((i2c->msg->flags & I2C_M_IGNORE_NAK) && 885 (isr & ISR_ACKNAK)))) { 886 int ret = BUS_ERROR; 887 888 /* 889 * I2C bus error - either the device NAK'd us, or 890 * something more serious happened. If we were NAK'd 891 * on the initial address phase, we can retry. 892 */ 893 if (isr & ISR_ACKNAK) { 894 if (i2c->msg_ptr == 0 && i2c->msg_idx == 0) 895 ret = NO_SLAVE; 896 else 897 ret = XFER_NAKED; 898 } 899 i2c_pxa_master_complete(i2c, ret); 900 } else if (isr & ISR_RWM) { 901 /* 902 * Read mode. We have just sent the address byte, and 903 * now we must initiate the transfer. 904 */ 905 if (i2c->msg_ptr == i2c->msg->len - 1 && 906 i2c->msg_idx == i2c->msg_num - 1) 907 icr |= ICR_STOP | ICR_ACKNAK; 908 909 icr |= ICR_ALDIE | ICR_TB; 910 } else if (i2c->msg_ptr < i2c->msg->len) { 911 /* 912 * Write mode. Write the next data byte. 913 */ 914 writel(i2c->msg->buf[i2c->msg_ptr++], _IDBR(i2c)); 915 916 icr |= ICR_ALDIE | ICR_TB; 917 918 /* 919 * If this is the last byte of the last message or last byte 920 * of any message with I2C_M_STOP (e.g. SCCB), send a STOP. 921 */ 922 if ((i2c->msg_ptr == i2c->msg->len) && 923 ((i2c->msg->flags & I2C_M_STOP) || 924 (i2c->msg_idx == i2c->msg_num - 1))) 925 icr |= ICR_STOP; 926 927 } else if (i2c->msg_idx < i2c->msg_num - 1) { 928 /* 929 * Next segment of the message. 930 */ 931 i2c->msg_ptr = 0; 932 i2c->msg_idx ++; 933 i2c->msg++; 934 935 /* 936 * If we aren't doing a repeated start and address, 937 * go back and try to send the next byte. Note that 938 * we do not support switching the R/W direction here. 939 */ 940 if (i2c->msg->flags & I2C_M_NOSTART) 941 goto again; 942 943 /* 944 * Write the next address. 945 */ 946 i2c->req_slave_addr = i2c_8bit_addr_from_msg(i2c->msg); 947 writel(i2c->req_slave_addr, _IDBR(i2c)); 948 949 /* 950 * And trigger a repeated start, and send the byte. 951 */ 952 icr &= ~ICR_ALDIE; 953 icr |= ICR_START | ICR_TB; 954 } else { 955 if (i2c->msg->len == 0) 956 icr |= ICR_MA; 957 i2c_pxa_master_complete(i2c, 0); 958 } 959 960 i2c->icrlog[i2c->irqlogidx-1] = icr; 961 962 writel(icr, _ICR(i2c)); 963 show_state(i2c); 964 } 965 966 static void i2c_pxa_irq_rxfull(struct pxa_i2c *i2c, u32 isr) 967 { 968 u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB); 969 970 /* 971 * Read the byte. 972 */ 973 i2c->msg->buf[i2c->msg_ptr++] = readl(_IDBR(i2c)); 974 975 if (i2c->msg_ptr < i2c->msg->len) { 976 /* 977 * If this is the last byte of the last 978 * message, send a STOP. 979 */ 980 if (i2c->msg_ptr == i2c->msg->len - 1) 981 icr |= ICR_STOP | ICR_ACKNAK; 982 983 icr |= ICR_ALDIE | ICR_TB; 984 } else { 985 i2c_pxa_master_complete(i2c, 0); 986 } 987 988 i2c->icrlog[i2c->irqlogidx-1] = icr; 989 990 writel(icr, _ICR(i2c)); 991 } 992 993 #define VALID_INT_SOURCE (ISR_SSD | ISR_ALD | ISR_ITE | ISR_IRF | \ 994 ISR_SAD | ISR_BED) 995 static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id) 996 { 997 struct pxa_i2c *i2c = dev_id; 998 u32 isr = readl(_ISR(i2c)); 999 1000 if (!(isr & VALID_INT_SOURCE)) 1001 return IRQ_NONE; 1002 1003 if (i2c_debug > 2 && 0) { 1004 dev_dbg(&i2c->adap.dev, "%s: ISR=%08x, ICR=%08x, IBMR=%02x\n", 1005 __func__, isr, readl(_ICR(i2c)), readl(_IBMR(i2c))); 1006 decode_ISR(isr); 1007 } 1008 1009 if (i2c->irqlogidx < ARRAY_SIZE(i2c->isrlog)) 1010 i2c->isrlog[i2c->irqlogidx++] = isr; 1011 1012 show_state(i2c); 1013 1014 /* 1015 * Always clear all pending IRQs. 1016 */ 1017 writel(isr & VALID_INT_SOURCE, _ISR(i2c)); 1018 1019 if (isr & ISR_SAD) 1020 i2c_pxa_slave_start(i2c, isr); 1021 if (isr & ISR_SSD) 1022 i2c_pxa_slave_stop(i2c); 1023 1024 if (i2c_pxa_is_slavemode(i2c)) { 1025 if (isr & ISR_ITE) 1026 i2c_pxa_slave_txempty(i2c, isr); 1027 if (isr & ISR_IRF) 1028 i2c_pxa_slave_rxfull(i2c, isr); 1029 } else if (i2c->msg && (!i2c->highmode_enter)) { 1030 if (isr & ISR_ITE) 1031 i2c_pxa_irq_txempty(i2c, isr); 1032 if (isr & ISR_IRF) 1033 i2c_pxa_irq_rxfull(i2c, isr); 1034 } else if ((isr & ISR_ITE) && i2c->highmode_enter) { 1035 i2c->highmode_enter = false; 1036 wake_up(&i2c->wait); 1037 } else { 1038 i2c_pxa_scream_blue_murder(i2c, "spurious irq"); 1039 } 1040 1041 return IRQ_HANDLED; 1042 } 1043 1044 /* 1045 * We are protected by the adapter bus mutex. 1046 */ 1047 static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num) 1048 { 1049 long timeout; 1050 int ret; 1051 1052 /* 1053 * Wait for the bus to become free. 1054 */ 1055 ret = i2c_pxa_wait_bus_not_busy(i2c); 1056 if (ret) { 1057 dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n"); 1058 i2c_recover_bus(&i2c->adap); 1059 goto out; 1060 } 1061 1062 /* 1063 * Set master mode. 1064 */ 1065 ret = i2c_pxa_set_master(i2c); 1066 if (ret) { 1067 dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret); 1068 goto out; 1069 } 1070 1071 if (i2c->high_mode) { 1072 ret = i2c_pxa_send_mastercode(i2c); 1073 if (ret) { 1074 dev_err(&i2c->adap.dev, "i2c_pxa_send_mastercode timeout\n"); 1075 goto out; 1076 } 1077 } 1078 1079 spin_lock_irq(&i2c->lock); 1080 1081 i2c->msg = msg; 1082 i2c->msg_num = num; 1083 i2c->msg_idx = 0; 1084 i2c->msg_ptr = 0; 1085 i2c->irqlogidx = 0; 1086 1087 i2c_pxa_start_message(i2c); 1088 1089 spin_unlock_irq(&i2c->lock); 1090 1091 /* 1092 * The rest of the processing occurs in the interrupt handler. 1093 */ 1094 timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5); 1095 i2c_pxa_stop_message(i2c); 1096 1097 /* 1098 * We place the return code in i2c->msg_idx. 1099 */ 1100 ret = i2c->msg_idx; 1101 1102 if (!timeout && i2c->msg_num) { 1103 i2c_pxa_scream_blue_murder(i2c, "timeout with active message"); 1104 i2c_recover_bus(&i2c->adap); 1105 ret = I2C_RETRY; 1106 } 1107 1108 out: 1109 return ret; 1110 } 1111 1112 static int i2c_pxa_internal_xfer(struct pxa_i2c *i2c, 1113 struct i2c_msg *msgs, int num, 1114 int (*xfer)(struct pxa_i2c *, 1115 struct i2c_msg *, int num)) 1116 { 1117 int ret, i; 1118 1119 for (i = 0; ; ) { 1120 ret = xfer(i2c, msgs, num); 1121 if (ret != I2C_RETRY && ret != NO_SLAVE) 1122 goto out; 1123 if (++i >= i2c->adap.retries) 1124 break; 1125 1126 if (i2c_debug) 1127 dev_dbg(&i2c->adap.dev, "Retrying transmission\n"); 1128 udelay(100); 1129 } 1130 if (ret != NO_SLAVE) 1131 i2c_pxa_scream_blue_murder(i2c, "exhausted retries"); 1132 ret = -EREMOTEIO; 1133 out: 1134 i2c_pxa_set_slave(i2c, ret); 1135 return ret; 1136 } 1137 1138 static int i2c_pxa_xfer(struct i2c_adapter *adap, 1139 struct i2c_msg msgs[], int num) 1140 { 1141 struct pxa_i2c *i2c = adap->algo_data; 1142 1143 return i2c_pxa_internal_xfer(i2c, msgs, num, i2c_pxa_do_xfer); 1144 } 1145 1146 static u32 i2c_pxa_functionality(struct i2c_adapter *adap) 1147 { 1148 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | 1149 I2C_FUNC_PROTOCOL_MANGLING | I2C_FUNC_NOSTART; 1150 } 1151 1152 static const struct i2c_algorithm i2c_pxa_algorithm = { 1153 .master_xfer = i2c_pxa_xfer, 1154 .functionality = i2c_pxa_functionality, 1155 #ifdef CONFIG_I2C_PXA_SLAVE 1156 .reg_slave = i2c_pxa_slave_reg, 1157 .unreg_slave = i2c_pxa_slave_unreg, 1158 #endif 1159 }; 1160 1161 /* Non-interrupt mode support */ 1162 static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c) 1163 { 1164 /* make timeout the same as for interrupt based functions */ 1165 long timeout = 2 * DEF_TIMEOUT; 1166 1167 /* 1168 * Wait for the bus to become free. 1169 */ 1170 while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) 1171 udelay(1000); 1172 1173 if (timeout < 0) { 1174 show_state(i2c); 1175 dev_err(&i2c->adap.dev, 1176 "i2c_pxa: timeout waiting for bus free (set_master)\n"); 1177 return I2C_RETRY; 1178 } 1179 1180 /* 1181 * Set master mode. 1182 */ 1183 writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c)); 1184 1185 return 0; 1186 } 1187 1188 static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c, 1189 struct i2c_msg *msg, int num) 1190 { 1191 unsigned long timeout = 500000; /* 5 seconds */ 1192 int ret = 0; 1193 1194 ret = i2c_pxa_pio_set_master(i2c); 1195 if (ret) 1196 goto out; 1197 1198 i2c->msg = msg; 1199 i2c->msg_num = num; 1200 i2c->msg_idx = 0; 1201 i2c->msg_ptr = 0; 1202 i2c->irqlogidx = 0; 1203 1204 i2c_pxa_start_message(i2c); 1205 1206 while (i2c->msg_num > 0 && --timeout) { 1207 i2c_pxa_handler(0, i2c); 1208 udelay(10); 1209 } 1210 1211 i2c_pxa_stop_message(i2c); 1212 1213 /* 1214 * We place the return code in i2c->msg_idx. 1215 */ 1216 ret = i2c->msg_idx; 1217 1218 out: 1219 if (timeout == 0) { 1220 i2c_pxa_scream_blue_murder(i2c, "timeout (do_pio_xfer)"); 1221 ret = I2C_RETRY; 1222 } 1223 1224 return ret; 1225 } 1226 1227 static int i2c_pxa_pio_xfer(struct i2c_adapter *adap, 1228 struct i2c_msg msgs[], int num) 1229 { 1230 struct pxa_i2c *i2c = adap->algo_data; 1231 1232 /* If the I2C controller is disabled we need to reset it 1233 (probably due to a suspend/resume destroying state). We do 1234 this here as we can then avoid worrying about resuming the 1235 controller before its users. */ 1236 if (!(readl(_ICR(i2c)) & ICR_IUE)) 1237 i2c_pxa_reset(i2c); 1238 1239 return i2c_pxa_internal_xfer(i2c, msgs, num, i2c_pxa_do_pio_xfer); 1240 } 1241 1242 static const struct i2c_algorithm i2c_pxa_pio_algorithm = { 1243 .master_xfer = i2c_pxa_pio_xfer, 1244 .functionality = i2c_pxa_functionality, 1245 #ifdef CONFIG_I2C_PXA_SLAVE 1246 .reg_slave = i2c_pxa_slave_reg, 1247 .unreg_slave = i2c_pxa_slave_unreg, 1248 #endif 1249 }; 1250 1251 static int i2c_pxa_probe_dt(struct platform_device *pdev, struct pxa_i2c *i2c, 1252 enum pxa_i2c_types *i2c_types) 1253 { 1254 struct device_node *np = pdev->dev.of_node; 1255 const struct of_device_id *of_id = 1256 of_match_device(i2c_pxa_dt_ids, &pdev->dev); 1257 1258 if (!of_id) 1259 return 1; 1260 1261 /* For device tree we always use the dynamic or alias-assigned ID */ 1262 i2c->adap.nr = -1; 1263 1264 i2c->use_pio = of_property_read_bool(np, "mrvl,i2c-polling"); 1265 i2c->fast_mode = of_property_read_bool(np, "mrvl,i2c-fast-mode"); 1266 1267 *i2c_types = (enum pxa_i2c_types)(of_id->data); 1268 1269 return 0; 1270 } 1271 1272 static int i2c_pxa_probe_pdata(struct platform_device *pdev, 1273 struct pxa_i2c *i2c, 1274 enum pxa_i2c_types *i2c_types) 1275 { 1276 struct i2c_pxa_platform_data *plat = dev_get_platdata(&pdev->dev); 1277 const struct platform_device_id *id = platform_get_device_id(pdev); 1278 1279 *i2c_types = id->driver_data; 1280 if (plat) { 1281 i2c->use_pio = plat->use_pio; 1282 i2c->fast_mode = plat->fast_mode; 1283 i2c->high_mode = plat->high_mode; 1284 i2c->master_code = plat->master_code; 1285 if (!i2c->master_code) 1286 i2c->master_code = 0xe; 1287 i2c->rate = plat->rate; 1288 } 1289 return 0; 1290 } 1291 1292 static void i2c_pxa_prepare_recovery(struct i2c_adapter *adap) 1293 { 1294 struct pxa_i2c *i2c = adap->algo_data; 1295 u32 ibmr = readl(_IBMR(i2c)); 1296 1297 /* 1298 * Program the GPIOs to reflect the current I2C bus state while 1299 * we transition to recovery; this avoids glitching the bus. 1300 */ 1301 gpiod_set_value(i2c->recovery.scl_gpiod, ibmr & IBMR_SCLS); 1302 gpiod_set_value(i2c->recovery.sda_gpiod, ibmr & IBMR_SDAS); 1303 } 1304 1305 static void i2c_pxa_unprepare_recovery(struct i2c_adapter *adap) 1306 { 1307 struct pxa_i2c *i2c = adap->algo_data; 1308 struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; 1309 u32 isr; 1310 1311 /* 1312 * The bus should now be free. Clear up the I2C controller before 1313 * handing control of the bus back to avoid the bus changing state. 1314 */ 1315 isr = readl(_ISR(i2c)); 1316 if (isr & (ISR_UB | ISR_IBB)) { 1317 dev_dbg(&i2c->adap.dev, 1318 "recovery: resetting controller, ISR=0x%08x\n", isr); 1319 i2c_pxa_do_reset(i2c); 1320 } 1321 1322 WARN_ON(pinctrl_select_state(bri->pinctrl, bri->pins_default)); 1323 1324 dev_dbg(&i2c->adap.dev, "recovery: IBMR 0x%08x ISR 0x%08x\n", 1325 readl(_IBMR(i2c)), readl(_ISR(i2c))); 1326 1327 i2c_pxa_enable(i2c); 1328 } 1329 1330 static int i2c_pxa_init_recovery(struct pxa_i2c *i2c) 1331 { 1332 struct i2c_bus_recovery_info *bri = &i2c->recovery; 1333 struct device *dev = i2c->adap.dev.parent; 1334 1335 /* 1336 * When slave mode is enabled, we are not the only master on the bus. 1337 * Bus recovery can only be performed when we are the master, which 1338 * we can't be certain of. Therefore, when slave mode is enabled, do 1339 * not configure bus recovery. 1340 */ 1341 if (IS_ENABLED(CONFIG_I2C_PXA_SLAVE)) 1342 return 0; 1343 1344 bri->pinctrl = devm_pinctrl_get(dev); 1345 if (PTR_ERR(bri->pinctrl) == -ENODEV) { 1346 bri->pinctrl = NULL; 1347 return 0; 1348 } 1349 if (IS_ERR(bri->pinctrl)) 1350 return PTR_ERR(bri->pinctrl); 1351 1352 bri->prepare_recovery = i2c_pxa_prepare_recovery; 1353 bri->unprepare_recovery = i2c_pxa_unprepare_recovery; 1354 1355 i2c->adap.bus_recovery_info = bri; 1356 1357 return 0; 1358 } 1359 1360 static int i2c_pxa_probe(struct platform_device *dev) 1361 { 1362 struct i2c_pxa_platform_data *plat = dev_get_platdata(&dev->dev); 1363 enum pxa_i2c_types i2c_type; 1364 struct pxa_i2c *i2c; 1365 struct resource *res; 1366 int ret, irq; 1367 1368 i2c = devm_kzalloc(&dev->dev, sizeof(struct pxa_i2c), GFP_KERNEL); 1369 if (!i2c) 1370 return -ENOMEM; 1371 1372 /* Default adapter num to device id; i2c_pxa_probe_dt can override. */ 1373 i2c->adap.nr = dev->id; 1374 i2c->adap.owner = THIS_MODULE; 1375 i2c->adap.retries = 5; 1376 i2c->adap.algo_data = i2c; 1377 i2c->adap.dev.parent = &dev->dev; 1378 #ifdef CONFIG_OF 1379 i2c->adap.dev.of_node = dev->dev.of_node; 1380 #endif 1381 1382 i2c->reg_base = devm_platform_get_and_ioremap_resource(dev, 0, &res); 1383 if (IS_ERR(i2c->reg_base)) 1384 return PTR_ERR(i2c->reg_base); 1385 1386 irq = platform_get_irq(dev, 0); 1387 if (irq < 0) 1388 return irq; 1389 1390 ret = i2c_pxa_init_recovery(i2c); 1391 if (ret) 1392 return ret; 1393 1394 ret = i2c_pxa_probe_dt(dev, i2c, &i2c_type); 1395 if (ret > 0) 1396 ret = i2c_pxa_probe_pdata(dev, i2c, &i2c_type); 1397 if (ret < 0) 1398 return ret; 1399 1400 spin_lock_init(&i2c->lock); 1401 init_waitqueue_head(&i2c->wait); 1402 1403 strscpy(i2c->adap.name, "pxa_i2c-i2c", sizeof(i2c->adap.name)); 1404 1405 i2c->clk = devm_clk_get(&dev->dev, NULL); 1406 if (IS_ERR(i2c->clk)) 1407 return dev_err_probe(&dev->dev, PTR_ERR(i2c->clk), 1408 "failed to get the clk\n"); 1409 1410 i2c->reg_ibmr = i2c->reg_base + pxa_reg_layout[i2c_type].ibmr; 1411 i2c->reg_idbr = i2c->reg_base + pxa_reg_layout[i2c_type].idbr; 1412 i2c->reg_icr = i2c->reg_base + pxa_reg_layout[i2c_type].icr; 1413 i2c->reg_isr = i2c->reg_base + pxa_reg_layout[i2c_type].isr; 1414 i2c->fm_mask = pxa_reg_layout[i2c_type].fm; 1415 i2c->hs_mask = pxa_reg_layout[i2c_type].hs; 1416 1417 if (i2c_type != REGS_CE4100) 1418 i2c->reg_isar = i2c->reg_base + pxa_reg_layout[i2c_type].isar; 1419 1420 if (i2c_type == REGS_PXA910) { 1421 i2c->reg_ilcr = i2c->reg_base + pxa_reg_layout[i2c_type].ilcr; 1422 i2c->reg_iwcr = i2c->reg_base + pxa_reg_layout[i2c_type].iwcr; 1423 } 1424 1425 i2c->iobase = res->start; 1426 i2c->iosize = resource_size(res); 1427 1428 i2c->irq = irq; 1429 1430 i2c->slave_addr = I2C_PXA_SLAVE_ADDR; 1431 i2c->highmode_enter = false; 1432 1433 if (plat) { 1434 i2c->adap.class = plat->class; 1435 } 1436 1437 if (i2c->high_mode) { 1438 if (i2c->rate) { 1439 clk_set_rate(i2c->clk, i2c->rate); 1440 pr_info("i2c: <%s> set rate to %ld\n", 1441 i2c->adap.name, clk_get_rate(i2c->clk)); 1442 } else 1443 pr_warn("i2c: <%s> clock rate not set\n", 1444 i2c->adap.name); 1445 } 1446 1447 clk_prepare_enable(i2c->clk); 1448 1449 if (i2c->use_pio) { 1450 i2c->adap.algo = &i2c_pxa_pio_algorithm; 1451 } else { 1452 i2c->adap.algo = &i2c_pxa_algorithm; 1453 ret = devm_request_irq(&dev->dev, irq, i2c_pxa_handler, 1454 IRQF_SHARED | IRQF_NO_SUSPEND, 1455 dev_name(&dev->dev), i2c); 1456 if (ret) { 1457 dev_err(&dev->dev, "failed to request irq: %d\n", ret); 1458 goto ereqirq; 1459 } 1460 } 1461 1462 i2c_pxa_reset(i2c); 1463 1464 ret = i2c_add_numbered_adapter(&i2c->adap); 1465 if (ret < 0) 1466 goto ereqirq; 1467 1468 platform_set_drvdata(dev, i2c); 1469 1470 #ifdef CONFIG_I2C_PXA_SLAVE 1471 dev_info(&i2c->adap.dev, " PXA I2C adapter, slave address %d\n", 1472 i2c->slave_addr); 1473 #else 1474 dev_info(&i2c->adap.dev, " PXA I2C adapter\n"); 1475 #endif 1476 return 0; 1477 1478 ereqirq: 1479 clk_disable_unprepare(i2c->clk); 1480 return ret; 1481 } 1482 1483 static void i2c_pxa_remove(struct platform_device *dev) 1484 { 1485 struct pxa_i2c *i2c = platform_get_drvdata(dev); 1486 1487 i2c_del_adapter(&i2c->adap); 1488 1489 clk_disable_unprepare(i2c->clk); 1490 } 1491 1492 static int i2c_pxa_suspend_noirq(struct device *dev) 1493 { 1494 struct pxa_i2c *i2c = dev_get_drvdata(dev); 1495 1496 clk_disable(i2c->clk); 1497 1498 return 0; 1499 } 1500 1501 static int i2c_pxa_resume_noirq(struct device *dev) 1502 { 1503 struct pxa_i2c *i2c = dev_get_drvdata(dev); 1504 1505 clk_enable(i2c->clk); 1506 i2c_pxa_reset(i2c); 1507 1508 return 0; 1509 } 1510 1511 static const struct dev_pm_ops i2c_pxa_dev_pm_ops = { 1512 .suspend_noirq = i2c_pxa_suspend_noirq, 1513 .resume_noirq = i2c_pxa_resume_noirq, 1514 }; 1515 1516 static struct platform_driver i2c_pxa_driver = { 1517 .probe = i2c_pxa_probe, 1518 .remove_new = i2c_pxa_remove, 1519 .driver = { 1520 .name = "pxa2xx-i2c", 1521 .pm = pm_sleep_ptr(&i2c_pxa_dev_pm_ops), 1522 .of_match_table = i2c_pxa_dt_ids, 1523 }, 1524 .id_table = i2c_pxa_id_table, 1525 }; 1526 1527 static int __init i2c_adap_pxa_init(void) 1528 { 1529 return platform_driver_register(&i2c_pxa_driver); 1530 } 1531 1532 static void __exit i2c_adap_pxa_exit(void) 1533 { 1534 platform_driver_unregister(&i2c_pxa_driver); 1535 } 1536 1537 MODULE_LICENSE("GPL"); 1538 1539 subsys_initcall(i2c_adap_pxa_init); 1540 module_exit(i2c_adap_pxa_exit); 1541