1 /* 2 * Copyright 2006,2009 Freescale Semiconductor, Inc. 3 * 4 * 2012, Heiko Schocher, DENX Software Engineering, hs@denx.de. 5 * Changes for multibus/multiadapter I2C support. 6 * 7 * SPDX-License-Identifier: GPL-2.0 8 */ 9 10 #include <common.h> 11 #include <command.h> 12 #include <i2c.h> /* Functional interface */ 13 #include <asm/io.h> 14 #include <asm/fsl_i2c.h> /* HW definitions */ 15 16 /* The maximum number of microseconds we will wait until another master has 17 * released the bus. If not defined in the board header file, then use a 18 * generic value. 19 */ 20 #ifndef CONFIG_I2C_MBB_TIMEOUT 21 #define CONFIG_I2C_MBB_TIMEOUT 100000 22 #endif 23 24 /* The maximum number of microseconds we will wait for a read or write 25 * operation to complete. If not defined in the board header file, then use a 26 * generic value. 27 */ 28 #ifndef CONFIG_I2C_TIMEOUT 29 #define CONFIG_I2C_TIMEOUT 100000 30 #endif 31 32 #define I2C_READ_BIT 1 33 #define I2C_WRITE_BIT 0 34 35 DECLARE_GLOBAL_DATA_PTR; 36 37 static const struct fsl_i2c *i2c_dev[4] = { 38 (struct fsl_i2c *)(CONFIG_SYS_IMMR + CONFIG_SYS_FSL_I2C_OFFSET), 39 #ifdef CONFIG_SYS_FSL_I2C2_OFFSET 40 (struct fsl_i2c *)(CONFIG_SYS_IMMR + CONFIG_SYS_FSL_I2C2_OFFSET), 41 #endif 42 #ifdef CONFIG_SYS_FSL_I2C3_OFFSET 43 (struct fsl_i2c *)(CONFIG_SYS_IMMR + CONFIG_SYS_FSL_I2C3_OFFSET), 44 #endif 45 #ifdef CONFIG_SYS_FSL_I2C4_OFFSET 46 (struct fsl_i2c *)(CONFIG_SYS_IMMR + CONFIG_SYS_FSL_I2C4_OFFSET) 47 #endif 48 }; 49 50 /* I2C speed map for a DFSR value of 1 */ 51 52 /* 53 * Map I2C frequency dividers to FDR and DFSR values 54 * 55 * This structure is used to define the elements of a table that maps I2C 56 * frequency divider (I2C clock rate divided by I2C bus speed) to a value to be 57 * programmed into the Frequency Divider Ratio (FDR) and Digital Filter 58 * Sampling Rate (DFSR) registers. 59 * 60 * The actual table should be defined in the board file, and it must be called 61 * fsl_i2c_speed_map[]. 62 * 63 * The last entry of the table must have a value of {-1, X}, where X is same 64 * FDR/DFSR values as the second-to-last entry. This guarantees that any 65 * search through the array will always find a match. 66 * 67 * The values of the divider must be in increasing numerical order, i.e. 68 * fsl_i2c_speed_map[x+1].divider > fsl_i2c_speed_map[x].divider. 69 * 70 * For this table, the values are based on a value of 1 for the DFSR 71 * register. See the application note AN2919 "Determining the I2C Frequency 72 * Divider Ratio for SCL" 73 * 74 * ColdFire I2C frequency dividers for FDR values are different from 75 * PowerPC. The protocol to use the I2C module is still the same. 76 * A different table is defined and are based on MCF5xxx user manual. 77 * 78 */ 79 static const struct { 80 unsigned short divider; 81 u8 fdr; 82 } fsl_i2c_speed_map[] = { 83 #ifdef __M68K__ 84 {20, 32}, {22, 33}, {24, 34}, {26, 35}, 85 {28, 0}, {28, 36}, {30, 1}, {32, 37}, 86 {34, 2}, {36, 38}, {40, 3}, {40, 39}, 87 {44, 4}, {48, 5}, {48, 40}, {56, 6}, 88 {56, 41}, {64, 42}, {68, 7}, {72, 43}, 89 {80, 8}, {80, 44}, {88, 9}, {96, 41}, 90 {104, 10}, {112, 42}, {128, 11}, {128, 43}, 91 {144, 12}, {160, 13}, {160, 48}, {192, 14}, 92 {192, 49}, {224, 50}, {240, 15}, {256, 51}, 93 {288, 16}, {320, 17}, {320, 52}, {384, 18}, 94 {384, 53}, {448, 54}, {480, 19}, {512, 55}, 95 {576, 20}, {640, 21}, {640, 56}, {768, 22}, 96 {768, 57}, {960, 23}, {896, 58}, {1024, 59}, 97 {1152, 24}, {1280, 25}, {1280, 60}, {1536, 26}, 98 {1536, 61}, {1792, 62}, {1920, 27}, {2048, 63}, 99 {2304, 28}, {2560, 29}, {3072, 30}, {3840, 31}, 100 {-1, 31} 101 #endif 102 }; 103 104 /** 105 * Set the I2C bus speed for a given I2C device 106 * 107 * @param dev: the I2C device 108 * @i2c_clk: I2C bus clock frequency 109 * @speed: the desired speed of the bus 110 * 111 * The I2C device must be stopped before calling this function. 112 * 113 * The return value is the actual bus speed that is set. 114 */ 115 static unsigned int set_i2c_bus_speed(const struct fsl_i2c *dev, 116 unsigned int i2c_clk, unsigned int speed) 117 { 118 unsigned short divider = min(i2c_clk / speed, (unsigned int)USHRT_MAX); 119 120 /* 121 * We want to choose an FDR/DFSR that generates an I2C bus speed that 122 * is equal to or lower than the requested speed. That means that we 123 * want the first divider that is equal to or greater than the 124 * calculated divider. 125 */ 126 #ifdef __PPC__ 127 u8 dfsr, fdr = 0x31; /* Default if no FDR found */ 128 /* a, b and dfsr matches identifiers A,B and C respectively in AN2919 */ 129 unsigned short a, b, ga, gb; 130 unsigned long c_div, est_div; 131 132 #ifdef CONFIG_FSL_I2C_CUSTOM_DFSR 133 dfsr = CONFIG_FSL_I2C_CUSTOM_DFSR; 134 #else 135 /* Condition 1: dfsr <= 50/T */ 136 dfsr = (5 * (i2c_clk / 1000)) / 100000; 137 #endif 138 #ifdef CONFIG_FSL_I2C_CUSTOM_FDR 139 fdr = CONFIG_FSL_I2C_CUSTOM_FDR; 140 speed = i2c_clk / divider; /* Fake something */ 141 #else 142 debug("Requested speed:%d, i2c_clk:%d\n", speed, i2c_clk); 143 if (!dfsr) 144 dfsr = 1; 145 146 est_div = ~0; 147 for (ga = 0x4, a = 10; a <= 30; ga++, a += 2) { 148 for (gb = 0; gb < 8; gb++) { 149 b = 16 << gb; 150 c_div = b * (a + ((3*dfsr)/b)*2); 151 if ((c_div > divider) && (c_div < est_div)) { 152 unsigned short bin_gb, bin_ga; 153 154 est_div = c_div; 155 bin_gb = gb << 2; 156 bin_ga = (ga & 0x3) | ((ga & 0x4) << 3); 157 fdr = bin_gb | bin_ga; 158 speed = i2c_clk / est_div; 159 debug("FDR:0x%.2x, div:%ld, ga:0x%x, gb:0x%x, " 160 "a:%d, b:%d, speed:%d\n", 161 fdr, est_div, ga, gb, a, b, speed); 162 /* Condition 2 not accounted for */ 163 debug("Tr <= %d ns\n", 164 (b - 3 * dfsr) * 1000000 / 165 (i2c_clk / 1000)); 166 } 167 } 168 if (a == 20) 169 a += 2; 170 if (a == 24) 171 a += 4; 172 } 173 debug("divider:%d, est_div:%ld, DFSR:%d\n", divider, est_div, dfsr); 174 debug("FDR:0x%.2x, speed:%d\n", fdr, speed); 175 #endif 176 writeb(dfsr, &dev->dfsrr); /* set default filter */ 177 writeb(fdr, &dev->fdr); /* set bus speed */ 178 #else 179 unsigned int i; 180 181 for (i = 0; i < ARRAY_SIZE(fsl_i2c_speed_map); i++) 182 if (fsl_i2c_speed_map[i].divider >= divider) { 183 u8 fdr; 184 185 fdr = fsl_i2c_speed_map[i].fdr; 186 speed = i2c_clk / fsl_i2c_speed_map[i].divider; 187 writeb(fdr, &dev->fdr); /* set bus speed */ 188 189 break; 190 } 191 #endif 192 return speed; 193 } 194 195 static unsigned int get_i2c_clock(int bus) 196 { 197 if (bus) 198 return gd->arch.i2c2_clk; /* I2C2 clock */ 199 else 200 return gd->arch.i2c1_clk; /* I2C1 clock */ 201 } 202 203 static int fsl_i2c_fixup(const struct fsl_i2c *dev) 204 { 205 const unsigned long long timeout = usec2ticks(CONFIG_I2C_MBB_TIMEOUT); 206 unsigned long long timeval = 0; 207 int ret = -1; 208 unsigned int flags = 0; 209 210 #ifdef CONFIG_SYS_FSL_ERRATUM_I2C_A004447 211 unsigned int svr = get_svr(); 212 if ((SVR_SOC_VER(svr) == SVR_8548 && IS_SVR_REV(svr, 3, 1)) || 213 (SVR_REV(svr) <= CONFIG_SYS_FSL_A004447_SVR_REV)) 214 flags = I2C_CR_BIT6; 215 #endif 216 217 writeb(I2C_CR_MEN | I2C_CR_MSTA, &dev->cr); 218 219 timeval = get_ticks(); 220 while (!(readb(&dev->sr) & I2C_SR_MBB)) { 221 if ((get_ticks() - timeval) > timeout) 222 goto err; 223 } 224 225 if (readb(&dev->sr) & I2C_SR_MAL) { 226 /* SDA is stuck low */ 227 writeb(0, &dev->cr); 228 udelay(100); 229 writeb(I2C_CR_MSTA | flags, &dev->cr); 230 writeb(I2C_CR_MEN | I2C_CR_MSTA | flags, &dev->cr); 231 } 232 233 readb(&dev->dr); 234 235 timeval = get_ticks(); 236 while (!(readb(&dev->sr) & I2C_SR_MIF)) { 237 if ((get_ticks() - timeval) > timeout) 238 goto err; 239 } 240 ret = 0; 241 242 err: 243 writeb(I2C_CR_MEN | flags, &dev->cr); 244 writeb(0, &dev->sr); 245 udelay(100); 246 247 return ret; 248 } 249 250 static void fsl_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd) 251 { 252 const struct fsl_i2c *dev; 253 const unsigned long long timeout = usec2ticks(CONFIG_I2C_MBB_TIMEOUT); 254 unsigned long long timeval; 255 256 #ifdef CONFIG_SYS_I2C_INIT_BOARD 257 /* Call board specific i2c bus reset routine before accessing the 258 * environment, which might be in a chip on that bus. For details 259 * about this problem see doc/I2C_Edge_Conditions. 260 */ 261 i2c_init_board(); 262 #endif 263 dev = (struct fsl_i2c *)i2c_dev[adap->hwadapnr]; 264 265 writeb(0, &dev->cr); /* stop I2C controller */ 266 udelay(5); /* let it shutdown in peace */ 267 set_i2c_bus_speed(dev, get_i2c_clock(adap->hwadapnr), speed); 268 writeb(slaveadd << 1, &dev->adr);/* write slave address */ 269 writeb(0x0, &dev->sr); /* clear status register */ 270 writeb(I2C_CR_MEN, &dev->cr); /* start I2C controller */ 271 272 timeval = get_ticks(); 273 while (readb(&dev->sr) & I2C_SR_MBB) { 274 if ((get_ticks() - timeval) < timeout) 275 continue; 276 277 if (fsl_i2c_fixup(dev)) 278 debug("i2c_init: BUS#%d failed to init\n", 279 adap->hwadapnr); 280 281 break; 282 } 283 284 #ifdef CONFIG_SYS_I2C_BOARD_LATE_INIT 285 /* Call board specific i2c bus reset routine AFTER the bus has been 286 * initialized. Use either this callpoint or i2c_init_board; 287 * which is called before i2c_init operations. 288 * For details about this problem see doc/I2C_Edge_Conditions. 289 */ 290 i2c_board_late_init(); 291 #endif 292 } 293 294 static int 295 i2c_wait4bus(struct i2c_adapter *adap) 296 { 297 struct fsl_i2c *dev = (struct fsl_i2c *)i2c_dev[adap->hwadapnr]; 298 unsigned long long timeval = get_ticks(); 299 const unsigned long long timeout = usec2ticks(CONFIG_I2C_MBB_TIMEOUT); 300 301 while (readb(&dev->sr) & I2C_SR_MBB) { 302 if ((get_ticks() - timeval) > timeout) 303 return -1; 304 } 305 306 return 0; 307 } 308 309 static __inline__ int 310 i2c_wait(struct i2c_adapter *adap, int write) 311 { 312 u32 csr; 313 unsigned long long timeval = get_ticks(); 314 const unsigned long long timeout = usec2ticks(CONFIG_I2C_TIMEOUT); 315 struct fsl_i2c *dev = (struct fsl_i2c *)i2c_dev[adap->hwadapnr]; 316 317 do { 318 csr = readb(&dev->sr); 319 if (!(csr & I2C_SR_MIF)) 320 continue; 321 /* Read again to allow register to stabilise */ 322 csr = readb(&dev->sr); 323 324 writeb(0x0, &dev->sr); 325 326 if (csr & I2C_SR_MAL) { 327 debug("i2c_wait: MAL\n"); 328 return -1; 329 } 330 331 if (!(csr & I2C_SR_MCF)) { 332 debug("i2c_wait: unfinished\n"); 333 return -1; 334 } 335 336 if (write == I2C_WRITE_BIT && (csr & I2C_SR_RXAK)) { 337 debug("i2c_wait: No RXACK\n"); 338 return -1; 339 } 340 341 return 0; 342 } while ((get_ticks() - timeval) < timeout); 343 344 debug("i2c_wait: timed out\n"); 345 return -1; 346 } 347 348 static __inline__ int 349 i2c_write_addr(struct i2c_adapter *adap, u8 dev, u8 dir, int rsta) 350 { 351 struct fsl_i2c *device = (struct fsl_i2c *)i2c_dev[adap->hwadapnr]; 352 353 writeb(I2C_CR_MEN | I2C_CR_MSTA | I2C_CR_MTX 354 | (rsta ? I2C_CR_RSTA : 0), 355 &device->cr); 356 357 writeb((dev << 1) | dir, &device->dr); 358 359 if (i2c_wait(adap, I2C_WRITE_BIT) < 0) 360 return 0; 361 362 return 1; 363 } 364 365 static __inline__ int 366 __i2c_write(struct i2c_adapter *adap, u8 *data, int length) 367 { 368 struct fsl_i2c *dev = (struct fsl_i2c *)i2c_dev[adap->hwadapnr]; 369 int i; 370 371 for (i = 0; i < length; i++) { 372 writeb(data[i], &dev->dr); 373 374 if (i2c_wait(adap, I2C_WRITE_BIT) < 0) 375 break; 376 } 377 378 return i; 379 } 380 381 static __inline__ int 382 __i2c_read(struct i2c_adapter *adap, u8 *data, int length) 383 { 384 struct fsl_i2c *dev = (struct fsl_i2c *)i2c_dev[adap->hwadapnr]; 385 int i; 386 387 writeb(I2C_CR_MEN | I2C_CR_MSTA | ((length == 1) ? I2C_CR_TXAK : 0), 388 &dev->cr); 389 390 /* dummy read */ 391 readb(&dev->dr); 392 393 for (i = 0; i < length; i++) { 394 if (i2c_wait(adap, I2C_READ_BIT) < 0) 395 break; 396 397 /* Generate ack on last next to last byte */ 398 if (i == length - 2) 399 writeb(I2C_CR_MEN | I2C_CR_MSTA | I2C_CR_TXAK, 400 &dev->cr); 401 402 /* Do not generate stop on last byte */ 403 if (i == length - 1) 404 writeb(I2C_CR_MEN | I2C_CR_MSTA | I2C_CR_MTX, 405 &dev->cr); 406 407 data[i] = readb(&dev->dr); 408 } 409 410 return i; 411 } 412 413 static int 414 fsl_i2c_read(struct i2c_adapter *adap, u8 dev, uint addr, int alen, u8 *data, 415 int length) 416 { 417 struct fsl_i2c *device = (struct fsl_i2c *)i2c_dev[adap->hwadapnr]; 418 int i = -1; /* signal error */ 419 u8 *a = (u8*)&addr; 420 int len = alen * -1; 421 422 if (i2c_wait4bus(adap) < 0) 423 return -1; 424 425 /* To handle the need of I2C devices that require to write few bytes 426 * (more than 4 bytes of address as in the case of else part) 427 * of data before reading, Negative equivalent of length(bytes to write) 428 * is passed, but used the +ve part of len for writing data 429 */ 430 if (alen < 0) { 431 /* Generate a START and send the Address and 432 * the Tx Bytes to the slave. 433 * "START: Address: Write bytes data[len]" 434 * IF part supports writing any number of bytes in contrast 435 * to the else part, which supports writing address offset 436 * of upto 4 bytes only. 437 * bytes that need to be written are passed in 438 * "data", which will eventually keep the data READ, 439 * after writing the len bytes out of it 440 */ 441 if (i2c_write_addr(adap, dev, I2C_WRITE_BIT, 0) != 0) 442 i = __i2c_write(adap, data, len); 443 444 if (i != len) 445 return -1; 446 447 if (length && i2c_write_addr(adap, dev, I2C_READ_BIT, 1) != 0) 448 i = __i2c_read(adap, data, length); 449 } else { 450 if ((!length || alen > 0) && 451 i2c_write_addr(adap, dev, I2C_WRITE_BIT, 0) != 0 && 452 __i2c_write(adap, &a[4 - alen], alen) == alen) 453 i = 0; /* No error so far */ 454 455 if (length && 456 i2c_write_addr(adap, dev, I2C_READ_BIT, alen ? 1 : 0) != 0) 457 i = __i2c_read(adap, data, length); 458 } 459 460 writeb(I2C_CR_MEN, &device->cr); 461 462 if (i2c_wait4bus(adap)) /* Wait until STOP */ 463 debug("i2c_read: wait4bus timed out\n"); 464 465 if (i == length) 466 return 0; 467 468 return -1; 469 } 470 471 static int 472 fsl_i2c_write(struct i2c_adapter *adap, u8 dev, uint addr, int alen, 473 u8 *data, int length) 474 { 475 struct fsl_i2c *device = (struct fsl_i2c *)i2c_dev[adap->hwadapnr]; 476 int i = -1; /* signal error */ 477 u8 *a = (u8*)&addr; 478 479 if (i2c_wait4bus(adap) < 0) 480 return -1; 481 482 if (i2c_write_addr(adap, dev, I2C_WRITE_BIT, 0) != 0 && 483 __i2c_write(adap, &a[4 - alen], alen) == alen) { 484 i = __i2c_write(adap, data, length); 485 } 486 487 writeb(I2C_CR_MEN, &device->cr); 488 if (i2c_wait4bus(adap)) /* Wait until STOP */ 489 debug("i2c_write: wait4bus timed out\n"); 490 491 if (i == length) 492 return 0; 493 494 return -1; 495 } 496 497 static int 498 fsl_i2c_probe(struct i2c_adapter *adap, uchar chip) 499 { 500 struct fsl_i2c *dev = (struct fsl_i2c *)i2c_dev[adap->hwadapnr]; 501 /* For unknow reason the controller will ACK when 502 * probing for a slave with the same address, so skip 503 * it. 504 */ 505 if (chip == (readb(&dev->adr) >> 1)) 506 return -1; 507 508 return fsl_i2c_read(adap, chip, 0, 0, NULL, 0); 509 } 510 511 static unsigned int fsl_i2c_set_bus_speed(struct i2c_adapter *adap, 512 unsigned int speed) 513 { 514 struct fsl_i2c *dev = (struct fsl_i2c *)i2c_dev[adap->hwadapnr]; 515 516 writeb(0, &dev->cr); /* stop controller */ 517 set_i2c_bus_speed(dev, get_i2c_clock(adap->hwadapnr), speed); 518 writeb(I2C_CR_MEN, &dev->cr); /* start controller */ 519 520 return 0; 521 } 522 523 /* 524 * Register fsl i2c adapters 525 */ 526 U_BOOT_I2C_ADAP_COMPLETE(fsl_0, fsl_i2c_init, fsl_i2c_probe, fsl_i2c_read, 527 fsl_i2c_write, fsl_i2c_set_bus_speed, 528 CONFIG_SYS_FSL_I2C_SPEED, CONFIG_SYS_FSL_I2C_SLAVE, 529 0) 530 #ifdef CONFIG_SYS_FSL_I2C2_OFFSET 531 U_BOOT_I2C_ADAP_COMPLETE(fsl_1, fsl_i2c_init, fsl_i2c_probe, fsl_i2c_read, 532 fsl_i2c_write, fsl_i2c_set_bus_speed, 533 CONFIG_SYS_FSL_I2C2_SPEED, CONFIG_SYS_FSL_I2C2_SLAVE, 534 1) 535 #endif 536 #ifdef CONFIG_SYS_FSL_I2C3_OFFSET 537 U_BOOT_I2C_ADAP_COMPLETE(fsl_2, fsl_i2c_init, fsl_i2c_probe, fsl_i2c_read, 538 fsl_i2c_write, fsl_i2c_set_bus_speed, 539 CONFIG_SYS_FSL_I2C3_SPEED, CONFIG_SYS_FSL_I2C3_SLAVE, 540 2) 541 #endif 542 #ifdef CONFIG_SYS_FSL_I2C4_OFFSET 543 U_BOOT_I2C_ADAP_COMPLETE(fsl_3, fsl_i2c_init, fsl_i2c_probe, fsl_i2c_read, 544 fsl_i2c_write, fsl_i2c_set_bus_speed, 545 CONFIG_SYS_FSL_I2C4_SPEED, CONFIG_SYS_FSL_I2C4_SLAVE, 546 3) 547 #endif 548