1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Driver for I2C adapter in Rockchip RK3xxx SoC 4 * 5 * Max Schwarz <max.schwarz@online.de> 6 * based on the patches by Rockchip Inc. 7 */ 8 9 #include <linux/kernel.h> 10 #include <linux/module.h> 11 #include <linux/i2c.h> 12 #include <linux/interrupt.h> 13 #include <linux/iopoll.h> 14 #include <linux/errno.h> 15 #include <linux/err.h> 16 #include <linux/platform_device.h> 17 #include <linux/io.h> 18 #include <linux/of_address.h> 19 #include <linux/of_irq.h> 20 #include <linux/spinlock.h> 21 #include <linux/clk.h> 22 #include <linux/wait.h> 23 #include <linux/mfd/syscon.h> 24 #include <linux/regmap.h> 25 #include <linux/math64.h> 26 27 28 /* Register Map */ 29 #define REG_CON 0x00 /* control register */ 30 #define REG_CLKDIV 0x04 /* clock divisor register */ 31 #define REG_MRXADDR 0x08 /* slave address for REGISTER_TX */ 32 #define REG_MRXRADDR 0x0c /* slave register address for REGISTER_TX */ 33 #define REG_MTXCNT 0x10 /* number of bytes to be transmitted */ 34 #define REG_MRXCNT 0x14 /* number of bytes to be received */ 35 #define REG_IEN 0x18 /* interrupt enable */ 36 #define REG_IPD 0x1c /* interrupt pending */ 37 #define REG_FCNT 0x20 /* finished count */ 38 39 /* Data buffer offsets */ 40 #define TXBUFFER_BASE 0x100 41 #define RXBUFFER_BASE 0x200 42 43 /* REG_CON bits */ 44 #define REG_CON_EN BIT(0) 45 enum { 46 REG_CON_MOD_TX = 0, /* transmit data */ 47 REG_CON_MOD_REGISTER_TX, /* select register and restart */ 48 REG_CON_MOD_RX, /* receive data */ 49 REG_CON_MOD_REGISTER_RX, /* broken: transmits read addr AND writes 50 * register addr */ 51 }; 52 #define REG_CON_MOD(mod) ((mod) << 1) 53 #define REG_CON_MOD_MASK (BIT(1) | BIT(2)) 54 #define REG_CON_START BIT(3) 55 #define REG_CON_STOP BIT(4) 56 #define REG_CON_LASTACK BIT(5) /* 1: send NACK after last received byte */ 57 #define REG_CON_ACTACK BIT(6) /* 1: stop if NACK is received */ 58 59 #define REG_CON_TUNING_MASK GENMASK_ULL(15, 8) 60 61 #define REG_CON_SDA_CFG(cfg) ((cfg) << 8) 62 #define REG_CON_STA_CFG(cfg) ((cfg) << 12) 63 #define REG_CON_STO_CFG(cfg) ((cfg) << 14) 64 65 /* REG_MRXADDR bits */ 66 #define REG_MRXADDR_VALID(x) BIT(24 + (x)) /* [x*8+7:x*8] of MRX[R]ADDR valid */ 67 68 /* REG_IEN/REG_IPD bits */ 69 #define REG_INT_BTF BIT(0) /* a byte was transmitted */ 70 #define REG_INT_BRF BIT(1) /* a byte was received */ 71 #define REG_INT_MBTF BIT(2) /* master data transmit finished */ 72 #define REG_INT_MBRF BIT(3) /* master data receive finished */ 73 #define REG_INT_START BIT(4) /* START condition generated */ 74 #define REG_INT_STOP BIT(5) /* STOP condition generated */ 75 #define REG_INT_NAKRCV BIT(6) /* NACK received */ 76 #define REG_INT_ALL 0x7f 77 78 /* Constants */ 79 #define WAIT_TIMEOUT 1000 /* ms */ 80 #define DEFAULT_SCL_RATE (100 * 1000) /* Hz */ 81 82 /** 83 * struct i2c_spec_values - I2C specification values for various modes 84 * @min_hold_start_ns: min hold time (repeated) START condition 85 * @min_low_ns: min LOW period of the SCL clock 86 * @min_high_ns: min HIGH period of the SCL cloc 87 * @min_setup_start_ns: min set-up time for a repeated START conditio 88 * @max_data_hold_ns: max data hold time 89 * @min_data_setup_ns: min data set-up time 90 * @min_setup_stop_ns: min set-up time for STOP condition 91 * @min_hold_buffer_ns: min bus free time between a STOP and 92 * START condition 93 */ 94 struct i2c_spec_values { 95 unsigned long min_hold_start_ns; 96 unsigned long min_low_ns; 97 unsigned long min_high_ns; 98 unsigned long min_setup_start_ns; 99 unsigned long max_data_hold_ns; 100 unsigned long min_data_setup_ns; 101 unsigned long min_setup_stop_ns; 102 unsigned long min_hold_buffer_ns; 103 }; 104 105 static const struct i2c_spec_values standard_mode_spec = { 106 .min_hold_start_ns = 4000, 107 .min_low_ns = 4700, 108 .min_high_ns = 4000, 109 .min_setup_start_ns = 4700, 110 .max_data_hold_ns = 3450, 111 .min_data_setup_ns = 250, 112 .min_setup_stop_ns = 4000, 113 .min_hold_buffer_ns = 4700, 114 }; 115 116 static const struct i2c_spec_values fast_mode_spec = { 117 .min_hold_start_ns = 600, 118 .min_low_ns = 1300, 119 .min_high_ns = 600, 120 .min_setup_start_ns = 600, 121 .max_data_hold_ns = 900, 122 .min_data_setup_ns = 100, 123 .min_setup_stop_ns = 600, 124 .min_hold_buffer_ns = 1300, 125 }; 126 127 static const struct i2c_spec_values fast_mode_plus_spec = { 128 .min_hold_start_ns = 260, 129 .min_low_ns = 500, 130 .min_high_ns = 260, 131 .min_setup_start_ns = 260, 132 .max_data_hold_ns = 400, 133 .min_data_setup_ns = 50, 134 .min_setup_stop_ns = 260, 135 .min_hold_buffer_ns = 500, 136 }; 137 138 /** 139 * struct rk3x_i2c_calced_timings - calculated V1 timings 140 * @div_low: Divider output for low 141 * @div_high: Divider output for high 142 * @tuning: Used to adjust setup/hold data time, 143 * setup/hold start time and setup stop time for 144 * v1's calc_timings, the tuning should all be 0 145 * for old hardware anyone using v0's calc_timings. 146 */ 147 struct rk3x_i2c_calced_timings { 148 unsigned long div_low; 149 unsigned long div_high; 150 unsigned int tuning; 151 }; 152 153 enum rk3x_i2c_state { 154 STATE_IDLE, 155 STATE_START, 156 STATE_READ, 157 STATE_WRITE, 158 STATE_STOP 159 }; 160 161 /** 162 * struct rk3x_i2c_soc_data - SOC-specific data 163 * @grf_offset: offset inside the grf regmap for setting the i2c type 164 * @calc_timings: Callback function for i2c timing information calculated 165 */ 166 struct rk3x_i2c_soc_data { 167 int grf_offset; 168 int (*calc_timings)(unsigned long, struct i2c_timings *, 169 struct rk3x_i2c_calced_timings *); 170 }; 171 172 /** 173 * struct rk3x_i2c - private data of the controller 174 * @adap: corresponding I2C adapter 175 * @dev: device for this controller 176 * @soc_data: related soc data struct 177 * @regs: virtual memory area 178 * @clk: function clk for rk3399 or function & Bus clks for others 179 * @pclk: Bus clk for rk3399 180 * @clk_rate_nb: i2c clk rate change notify 181 * @irq: irq number 182 * @t: I2C known timing information 183 * @lock: spinlock for the i2c bus 184 * @wait: the waitqueue to wait for i2c transfer 185 * @busy: the condition for the event to wait for 186 * @msg: current i2c message 187 * @addr: addr of i2c slave device 188 * @mode: mode of i2c transfer 189 * @is_last_msg: flag determines whether it is the last msg in this transfer 190 * @state: state of i2c transfer 191 * @processed: byte length which has been send or received 192 * @error: error code for i2c transfer 193 */ 194 struct rk3x_i2c { 195 struct i2c_adapter adap; 196 struct device *dev; 197 const struct rk3x_i2c_soc_data *soc_data; 198 199 /* Hardware resources */ 200 void __iomem *regs; 201 struct clk *clk; 202 struct clk *pclk; 203 struct notifier_block clk_rate_nb; 204 int irq; 205 206 /* Settings */ 207 struct i2c_timings t; 208 209 /* Synchronization & notification */ 210 spinlock_t lock; 211 wait_queue_head_t wait; 212 bool busy; 213 214 /* Current message */ 215 struct i2c_msg *msg; 216 u8 addr; 217 unsigned int mode; 218 bool is_last_msg; 219 220 /* I2C state machine */ 221 enum rk3x_i2c_state state; 222 unsigned int processed; 223 int error; 224 }; 225 226 static inline void i2c_writel(struct rk3x_i2c *i2c, u32 value, 227 unsigned int offset) 228 { 229 writel(value, i2c->regs + offset); 230 } 231 232 static inline u32 i2c_readl(struct rk3x_i2c *i2c, unsigned int offset) 233 { 234 return readl(i2c->regs + offset); 235 } 236 237 /* Reset all interrupt pending bits */ 238 static inline void rk3x_i2c_clean_ipd(struct rk3x_i2c *i2c) 239 { 240 i2c_writel(i2c, REG_INT_ALL, REG_IPD); 241 } 242 243 /** 244 * rk3x_i2c_start - Generate a START condition, which triggers a REG_INT_START interrupt. 245 * @i2c: target controller data 246 */ 247 static void rk3x_i2c_start(struct rk3x_i2c *i2c) 248 { 249 u32 val = i2c_readl(i2c, REG_CON) & REG_CON_TUNING_MASK; 250 251 i2c_writel(i2c, REG_INT_START, REG_IEN); 252 253 /* enable adapter with correct mode, send START condition */ 254 val |= REG_CON_EN | REG_CON_MOD(i2c->mode) | REG_CON_START; 255 256 /* if we want to react to NACK, set ACTACK bit */ 257 if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) 258 val |= REG_CON_ACTACK; 259 260 i2c_writel(i2c, val, REG_CON); 261 } 262 263 /** 264 * rk3x_i2c_stop - Generate a STOP condition, which triggers a REG_INT_STOP interrupt. 265 * @i2c: target controller data 266 * @error: Error code to return in rk3x_i2c_xfer 267 */ 268 static void rk3x_i2c_stop(struct rk3x_i2c *i2c, int error) 269 { 270 unsigned int ctrl; 271 272 i2c->processed = 0; 273 i2c->msg = NULL; 274 i2c->error = error; 275 276 if (i2c->is_last_msg) { 277 /* Enable stop interrupt */ 278 i2c_writel(i2c, REG_INT_STOP, REG_IEN); 279 280 i2c->state = STATE_STOP; 281 282 ctrl = i2c_readl(i2c, REG_CON); 283 ctrl |= REG_CON_STOP; 284 i2c_writel(i2c, ctrl, REG_CON); 285 } else { 286 /* Signal rk3x_i2c_xfer to start the next message. */ 287 i2c->busy = false; 288 i2c->state = STATE_IDLE; 289 290 /* 291 * The HW is actually not capable of REPEATED START. But we can 292 * get the intended effect by resetting its internal state 293 * and issuing an ordinary START. 294 */ 295 ctrl = i2c_readl(i2c, REG_CON) & REG_CON_TUNING_MASK; 296 i2c_writel(i2c, ctrl, REG_CON); 297 298 /* signal that we are finished with the current msg */ 299 wake_up(&i2c->wait); 300 } 301 } 302 303 /** 304 * rk3x_i2c_prepare_read - Setup a read according to i2c->msg 305 * @i2c: target controller data 306 */ 307 static void rk3x_i2c_prepare_read(struct rk3x_i2c *i2c) 308 { 309 unsigned int len = i2c->msg->len - i2c->processed; 310 u32 con; 311 312 con = i2c_readl(i2c, REG_CON); 313 314 /* 315 * The hw can read up to 32 bytes at a time. If we need more than one 316 * chunk, send an ACK after the last byte of the current chunk. 317 */ 318 if (len > 32) { 319 len = 32; 320 con &= ~REG_CON_LASTACK; 321 } else { 322 con |= REG_CON_LASTACK; 323 } 324 325 /* make sure we are in plain RX mode if we read a second chunk */ 326 if (i2c->processed != 0) { 327 con &= ~REG_CON_MOD_MASK; 328 con |= REG_CON_MOD(REG_CON_MOD_RX); 329 } 330 331 i2c_writel(i2c, con, REG_CON); 332 i2c_writel(i2c, len, REG_MRXCNT); 333 } 334 335 /** 336 * rk3x_i2c_fill_transmit_buf - Fill the transmit buffer with data from i2c->msg 337 * @i2c: target controller data 338 */ 339 static void rk3x_i2c_fill_transmit_buf(struct rk3x_i2c *i2c) 340 { 341 unsigned int i, j; 342 u32 cnt = 0; 343 u32 val; 344 u8 byte; 345 346 for (i = 0; i < 8; ++i) { 347 val = 0; 348 for (j = 0; j < 4; ++j) { 349 if ((i2c->processed == i2c->msg->len) && (cnt != 0)) 350 break; 351 352 if (i2c->processed == 0 && cnt == 0) 353 byte = (i2c->addr & 0x7f) << 1; 354 else 355 byte = i2c->msg->buf[i2c->processed++]; 356 357 val |= byte << (j * 8); 358 cnt++; 359 } 360 361 i2c_writel(i2c, val, TXBUFFER_BASE + 4 * i); 362 363 if (i2c->processed == i2c->msg->len) 364 break; 365 } 366 367 i2c_writel(i2c, cnt, REG_MTXCNT); 368 } 369 370 371 /* IRQ handlers for individual states */ 372 373 static void rk3x_i2c_handle_start(struct rk3x_i2c *i2c, unsigned int ipd) 374 { 375 if (!(ipd & REG_INT_START)) { 376 rk3x_i2c_stop(i2c, -EIO); 377 dev_warn(i2c->dev, "unexpected irq in START: 0x%x\n", ipd); 378 rk3x_i2c_clean_ipd(i2c); 379 return; 380 } 381 382 /* ack interrupt */ 383 i2c_writel(i2c, REG_INT_START, REG_IPD); 384 385 /* disable start bit */ 386 i2c_writel(i2c, i2c_readl(i2c, REG_CON) & ~REG_CON_START, REG_CON); 387 388 /* enable appropriate interrupts and transition */ 389 if (i2c->mode == REG_CON_MOD_TX) { 390 i2c_writel(i2c, REG_INT_MBTF | REG_INT_NAKRCV, REG_IEN); 391 i2c->state = STATE_WRITE; 392 rk3x_i2c_fill_transmit_buf(i2c); 393 } else { 394 /* in any other case, we are going to be reading. */ 395 i2c_writel(i2c, REG_INT_MBRF | REG_INT_NAKRCV, REG_IEN); 396 i2c->state = STATE_READ; 397 rk3x_i2c_prepare_read(i2c); 398 } 399 } 400 401 static void rk3x_i2c_handle_write(struct rk3x_i2c *i2c, unsigned int ipd) 402 { 403 if (!(ipd & REG_INT_MBTF)) { 404 rk3x_i2c_stop(i2c, -EIO); 405 dev_err(i2c->dev, "unexpected irq in WRITE: 0x%x\n", ipd); 406 rk3x_i2c_clean_ipd(i2c); 407 return; 408 } 409 410 /* ack interrupt */ 411 i2c_writel(i2c, REG_INT_MBTF, REG_IPD); 412 413 /* are we finished? */ 414 if (i2c->processed == i2c->msg->len) 415 rk3x_i2c_stop(i2c, i2c->error); 416 else 417 rk3x_i2c_fill_transmit_buf(i2c); 418 } 419 420 static void rk3x_i2c_handle_read(struct rk3x_i2c *i2c, unsigned int ipd) 421 { 422 unsigned int i; 423 unsigned int len = i2c->msg->len - i2c->processed; 424 u32 val; 425 u8 byte; 426 427 /* we only care for MBRF here. */ 428 if (!(ipd & REG_INT_MBRF)) 429 return; 430 431 /* ack interrupt (read also produces a spurious START flag, clear it too) */ 432 i2c_writel(i2c, REG_INT_MBRF | REG_INT_START, REG_IPD); 433 434 /* Can only handle a maximum of 32 bytes at a time */ 435 if (len > 32) 436 len = 32; 437 438 /* read the data from receive buffer */ 439 for (i = 0; i < len; ++i) { 440 if (i % 4 == 0) 441 val = i2c_readl(i2c, RXBUFFER_BASE + (i / 4) * 4); 442 443 byte = (val >> ((i % 4) * 8)) & 0xff; 444 i2c->msg->buf[i2c->processed++] = byte; 445 } 446 447 /* are we finished? */ 448 if (i2c->processed == i2c->msg->len) 449 rk3x_i2c_stop(i2c, i2c->error); 450 else 451 rk3x_i2c_prepare_read(i2c); 452 } 453 454 static void rk3x_i2c_handle_stop(struct rk3x_i2c *i2c, unsigned int ipd) 455 { 456 unsigned int con; 457 458 if (!(ipd & REG_INT_STOP)) { 459 rk3x_i2c_stop(i2c, -EIO); 460 dev_err(i2c->dev, "unexpected irq in STOP: 0x%x\n", ipd); 461 rk3x_i2c_clean_ipd(i2c); 462 return; 463 } 464 465 /* ack interrupt */ 466 i2c_writel(i2c, REG_INT_STOP, REG_IPD); 467 468 /* disable STOP bit */ 469 con = i2c_readl(i2c, REG_CON); 470 con &= ~REG_CON_STOP; 471 i2c_writel(i2c, con, REG_CON); 472 473 i2c->busy = false; 474 i2c->state = STATE_IDLE; 475 476 /* signal rk3x_i2c_xfer that we are finished */ 477 wake_up(&i2c->wait); 478 } 479 480 static irqreturn_t rk3x_i2c_irq(int irqno, void *dev_id) 481 { 482 struct rk3x_i2c *i2c = dev_id; 483 unsigned int ipd; 484 485 spin_lock(&i2c->lock); 486 487 ipd = i2c_readl(i2c, REG_IPD); 488 if (i2c->state == STATE_IDLE) { 489 dev_warn(i2c->dev, "irq in STATE_IDLE, ipd = 0x%x\n", ipd); 490 rk3x_i2c_clean_ipd(i2c); 491 goto out; 492 } 493 494 dev_dbg(i2c->dev, "IRQ: state %d, ipd: %x\n", i2c->state, ipd); 495 496 /* Clean interrupt bits we don't care about */ 497 ipd &= ~(REG_INT_BRF | REG_INT_BTF); 498 499 if (ipd & REG_INT_NAKRCV) { 500 /* 501 * We got a NACK in the last operation. Depending on whether 502 * IGNORE_NAK is set, we have to stop the operation and report 503 * an error. 504 */ 505 i2c_writel(i2c, REG_INT_NAKRCV, REG_IPD); 506 507 ipd &= ~REG_INT_NAKRCV; 508 509 if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) 510 rk3x_i2c_stop(i2c, -ENXIO); 511 } 512 513 /* is there anything left to handle? */ 514 if ((ipd & REG_INT_ALL) == 0) 515 goto out; 516 517 switch (i2c->state) { 518 case STATE_START: 519 rk3x_i2c_handle_start(i2c, ipd); 520 break; 521 case STATE_WRITE: 522 rk3x_i2c_handle_write(i2c, ipd); 523 break; 524 case STATE_READ: 525 rk3x_i2c_handle_read(i2c, ipd); 526 break; 527 case STATE_STOP: 528 rk3x_i2c_handle_stop(i2c, ipd); 529 break; 530 case STATE_IDLE: 531 break; 532 } 533 534 out: 535 spin_unlock(&i2c->lock); 536 return IRQ_HANDLED; 537 } 538 539 /** 540 * rk3x_i2c_get_spec - Get timing values of I2C specification 541 * @speed: Desired SCL frequency 542 * 543 * Return: Matched i2c_spec_values. 544 */ 545 static const struct i2c_spec_values *rk3x_i2c_get_spec(unsigned int speed) 546 { 547 if (speed <= I2C_MAX_STANDARD_MODE_FREQ) 548 return &standard_mode_spec; 549 else if (speed <= I2C_MAX_FAST_MODE_FREQ) 550 return &fast_mode_spec; 551 else 552 return &fast_mode_plus_spec; 553 } 554 555 /** 556 * rk3x_i2c_v0_calc_timings - Calculate divider values for desired SCL frequency 557 * @clk_rate: I2C input clock rate 558 * @t: Known I2C timing information 559 * @t_calc: Caculated rk3x private timings that would be written into regs 560 * 561 * Return: %0 on success, -%EINVAL if the goal SCL rate is too slow. In that case 562 * a best-effort divider value is returned in divs. If the target rate is 563 * too high, we silently use the highest possible rate. 564 */ 565 static int rk3x_i2c_v0_calc_timings(unsigned long clk_rate, 566 struct i2c_timings *t, 567 struct rk3x_i2c_calced_timings *t_calc) 568 { 569 unsigned long min_low_ns, min_high_ns; 570 unsigned long max_low_ns, min_total_ns; 571 572 unsigned long clk_rate_khz, scl_rate_khz; 573 574 unsigned long min_low_div, min_high_div; 575 unsigned long max_low_div; 576 577 unsigned long min_div_for_hold, min_total_div; 578 unsigned long extra_div, extra_low_div, ideal_low_div; 579 580 unsigned long data_hold_buffer_ns = 50; 581 const struct i2c_spec_values *spec; 582 int ret = 0; 583 584 /* Only support standard-mode and fast-mode */ 585 if (WARN_ON(t->bus_freq_hz > I2C_MAX_FAST_MODE_FREQ)) 586 t->bus_freq_hz = I2C_MAX_FAST_MODE_FREQ; 587 588 /* prevent scl_rate_khz from becoming 0 */ 589 if (WARN_ON(t->bus_freq_hz < 1000)) 590 t->bus_freq_hz = 1000; 591 592 /* 593 * min_low_ns: The minimum number of ns we need to hold low to 594 * meet I2C specification, should include fall time. 595 * min_high_ns: The minimum number of ns we need to hold high to 596 * meet I2C specification, should include rise time. 597 * max_low_ns: The maximum number of ns we can hold low to meet 598 * I2C specification. 599 * 600 * Note: max_low_ns should be (maximum data hold time * 2 - buffer) 601 * This is because the i2c host on Rockchip holds the data line 602 * for half the low time. 603 */ 604 spec = rk3x_i2c_get_spec(t->bus_freq_hz); 605 min_high_ns = t->scl_rise_ns + spec->min_high_ns; 606 607 /* 608 * Timings for repeated start: 609 * - controller appears to drop SDA at .875x (7/8) programmed clk high. 610 * - controller appears to keep SCL high for 2x programmed clk high. 611 * 612 * We need to account for those rules in picking our "high" time so 613 * we meet tSU;STA and tHD;STA times. 614 */ 615 min_high_ns = max(min_high_ns, DIV_ROUND_UP( 616 (t->scl_rise_ns + spec->min_setup_start_ns) * 1000, 875)); 617 min_high_ns = max(min_high_ns, DIV_ROUND_UP( 618 (t->scl_rise_ns + spec->min_setup_start_ns + t->sda_fall_ns + 619 spec->min_high_ns), 2)); 620 621 min_low_ns = t->scl_fall_ns + spec->min_low_ns; 622 max_low_ns = spec->max_data_hold_ns * 2 - data_hold_buffer_ns; 623 min_total_ns = min_low_ns + min_high_ns; 624 625 /* Adjust to avoid overflow */ 626 clk_rate_khz = DIV_ROUND_UP(clk_rate, 1000); 627 scl_rate_khz = t->bus_freq_hz / 1000; 628 629 /* 630 * We need the total div to be >= this number 631 * so we don't clock too fast. 632 */ 633 min_total_div = DIV_ROUND_UP(clk_rate_khz, scl_rate_khz * 8); 634 635 /* These are the min dividers needed for min hold times. */ 636 min_low_div = DIV_ROUND_UP(clk_rate_khz * min_low_ns, 8 * 1000000); 637 min_high_div = DIV_ROUND_UP(clk_rate_khz * min_high_ns, 8 * 1000000); 638 min_div_for_hold = (min_low_div + min_high_div); 639 640 /* 641 * This is the maximum divider so we don't go over the maximum. 642 * We don't round up here (we round down) since this is a maximum. 643 */ 644 max_low_div = clk_rate_khz * max_low_ns / (8 * 1000000); 645 646 if (min_low_div > max_low_div) { 647 WARN_ONCE(true, 648 "Conflicting, min_low_div %lu, max_low_div %lu\n", 649 min_low_div, max_low_div); 650 max_low_div = min_low_div; 651 } 652 653 if (min_div_for_hold > min_total_div) { 654 /* 655 * Time needed to meet hold requirements is important. 656 * Just use that. 657 */ 658 t_calc->div_low = min_low_div; 659 t_calc->div_high = min_high_div; 660 } else { 661 /* 662 * We've got to distribute some time among the low and high 663 * so we don't run too fast. 664 */ 665 extra_div = min_total_div - min_div_for_hold; 666 667 /* 668 * We'll try to split things up perfectly evenly, 669 * biasing slightly towards having a higher div 670 * for low (spend more time low). 671 */ 672 ideal_low_div = DIV_ROUND_UP(clk_rate_khz * min_low_ns, 673 scl_rate_khz * 8 * min_total_ns); 674 675 /* Don't allow it to go over the maximum */ 676 if (ideal_low_div > max_low_div) 677 ideal_low_div = max_low_div; 678 679 /* 680 * Handle when the ideal low div is going to take up 681 * more than we have. 682 */ 683 if (ideal_low_div > min_low_div + extra_div) 684 ideal_low_div = min_low_div + extra_div; 685 686 /* Give low the "ideal" and give high whatever extra is left */ 687 extra_low_div = ideal_low_div - min_low_div; 688 t_calc->div_low = ideal_low_div; 689 t_calc->div_high = min_high_div + (extra_div - extra_low_div); 690 } 691 692 /* 693 * Adjust to the fact that the hardware has an implicit "+1". 694 * NOTE: Above calculations always produce div_low > 0 and div_high > 0. 695 */ 696 t_calc->div_low--; 697 t_calc->div_high--; 698 699 /* Give the tuning value 0, that would not update con register */ 700 t_calc->tuning = 0; 701 /* Maximum divider supported by hw is 0xffff */ 702 if (t_calc->div_low > 0xffff) { 703 t_calc->div_low = 0xffff; 704 ret = -EINVAL; 705 } 706 707 if (t_calc->div_high > 0xffff) { 708 t_calc->div_high = 0xffff; 709 ret = -EINVAL; 710 } 711 712 return ret; 713 } 714 715 /** 716 * rk3x_i2c_v1_calc_timings - Calculate timing values for desired SCL frequency 717 * @clk_rate: I2C input clock rate 718 * @t: Known I2C timing information 719 * @t_calc: Caculated rk3x private timings that would be written into regs 720 * 721 * Return: %0 on success, -%EINVAL if the goal SCL rate is too slow. In that case 722 * a best-effort divider value is returned in divs. If the target rate is 723 * too high, we silently use the highest possible rate. 724 * The following formulas are v1's method to calculate timings. 725 * 726 * l = divl + 1; 727 * h = divh + 1; 728 * s = sda_update_config + 1; 729 * u = start_setup_config + 1; 730 * p = stop_setup_config + 1; 731 * T = Tclk_i2c; 732 * 733 * tHigh = 8 * h * T; 734 * tLow = 8 * l * T; 735 * 736 * tHD;sda = (l * s + 1) * T; 737 * tSU;sda = [(8 - s) * l + 1] * T; 738 * tI2C = 8 * (l + h) * T; 739 * 740 * tSU;sta = (8h * u + 1) * T; 741 * tHD;sta = [8h * (u + 1) - 1] * T; 742 * tSU;sto = (8h * p + 1) * T; 743 */ 744 static int rk3x_i2c_v1_calc_timings(unsigned long clk_rate, 745 struct i2c_timings *t, 746 struct rk3x_i2c_calced_timings *t_calc) 747 { 748 unsigned long min_low_ns, min_high_ns; 749 unsigned long min_setup_start_ns, min_setup_data_ns; 750 unsigned long min_setup_stop_ns, max_hold_data_ns; 751 752 unsigned long clk_rate_khz, scl_rate_khz; 753 754 unsigned long min_low_div, min_high_div; 755 756 unsigned long min_div_for_hold, min_total_div; 757 unsigned long extra_div, extra_low_div; 758 unsigned long sda_update_cfg, stp_sta_cfg, stp_sto_cfg; 759 760 const struct i2c_spec_values *spec; 761 int ret = 0; 762 763 /* Support standard-mode, fast-mode and fast-mode plus */ 764 if (WARN_ON(t->bus_freq_hz > I2C_MAX_FAST_MODE_PLUS_FREQ)) 765 t->bus_freq_hz = I2C_MAX_FAST_MODE_PLUS_FREQ; 766 767 /* prevent scl_rate_khz from becoming 0 */ 768 if (WARN_ON(t->bus_freq_hz < 1000)) 769 t->bus_freq_hz = 1000; 770 771 /* 772 * min_low_ns: The minimum number of ns we need to hold low to 773 * meet I2C specification, should include fall time. 774 * min_high_ns: The minimum number of ns we need to hold high to 775 * meet I2C specification, should include rise time. 776 */ 777 spec = rk3x_i2c_get_spec(t->bus_freq_hz); 778 779 /* calculate min-divh and min-divl */ 780 clk_rate_khz = DIV_ROUND_UP(clk_rate, 1000); 781 scl_rate_khz = t->bus_freq_hz / 1000; 782 min_total_div = DIV_ROUND_UP(clk_rate_khz, scl_rate_khz * 8); 783 784 min_high_ns = t->scl_rise_ns + spec->min_high_ns; 785 min_high_div = DIV_ROUND_UP(clk_rate_khz * min_high_ns, 8 * 1000000); 786 787 min_low_ns = t->scl_fall_ns + spec->min_low_ns; 788 min_low_div = DIV_ROUND_UP(clk_rate_khz * min_low_ns, 8 * 1000000); 789 790 /* 791 * Final divh and divl must be greater than 0, otherwise the 792 * hardware would not output the i2c clk. 793 */ 794 min_high_div = (min_high_div < 1) ? 2 : min_high_div; 795 min_low_div = (min_low_div < 1) ? 2 : min_low_div; 796 797 /* These are the min dividers needed for min hold times. */ 798 min_div_for_hold = (min_low_div + min_high_div); 799 800 /* 801 * This is the maximum divider so we don't go over the maximum. 802 * We don't round up here (we round down) since this is a maximum. 803 */ 804 if (min_div_for_hold >= min_total_div) { 805 /* 806 * Time needed to meet hold requirements is important. 807 * Just use that. 808 */ 809 t_calc->div_low = min_low_div; 810 t_calc->div_high = min_high_div; 811 } else { 812 /* 813 * We've got to distribute some time among the low and high 814 * so we don't run too fast. 815 * We'll try to split things up by the scale of min_low_div and 816 * min_high_div, biasing slightly towards having a higher div 817 * for low (spend more time low). 818 */ 819 extra_div = min_total_div - min_div_for_hold; 820 extra_low_div = DIV_ROUND_UP(min_low_div * extra_div, 821 min_div_for_hold); 822 823 t_calc->div_low = min_low_div + extra_low_div; 824 t_calc->div_high = min_high_div + (extra_div - extra_low_div); 825 } 826 827 /* 828 * calculate sda data hold count by the rules, data_upd_st:3 829 * is a appropriate value to reduce calculated times. 830 */ 831 for (sda_update_cfg = 3; sda_update_cfg > 0; sda_update_cfg--) { 832 max_hold_data_ns = DIV_ROUND_UP((sda_update_cfg 833 * (t_calc->div_low) + 1) 834 * 1000000, clk_rate_khz); 835 min_setup_data_ns = DIV_ROUND_UP(((8 - sda_update_cfg) 836 * (t_calc->div_low) + 1) 837 * 1000000, clk_rate_khz); 838 if ((max_hold_data_ns < spec->max_data_hold_ns) && 839 (min_setup_data_ns > spec->min_data_setup_ns)) 840 break; 841 } 842 843 /* calculate setup start config */ 844 min_setup_start_ns = t->scl_rise_ns + spec->min_setup_start_ns; 845 stp_sta_cfg = DIV_ROUND_UP(clk_rate_khz * min_setup_start_ns 846 - 1000000, 8 * 1000000 * (t_calc->div_high)); 847 848 /* calculate setup stop config */ 849 min_setup_stop_ns = t->scl_rise_ns + spec->min_setup_stop_ns; 850 stp_sto_cfg = DIV_ROUND_UP(clk_rate_khz * min_setup_stop_ns 851 - 1000000, 8 * 1000000 * (t_calc->div_high)); 852 853 t_calc->tuning = REG_CON_SDA_CFG(--sda_update_cfg) | 854 REG_CON_STA_CFG(--stp_sta_cfg) | 855 REG_CON_STO_CFG(--stp_sto_cfg); 856 857 t_calc->div_low--; 858 t_calc->div_high--; 859 860 /* Maximum divider supported by hw is 0xffff */ 861 if (t_calc->div_low > 0xffff) { 862 t_calc->div_low = 0xffff; 863 ret = -EINVAL; 864 } 865 866 if (t_calc->div_high > 0xffff) { 867 t_calc->div_high = 0xffff; 868 ret = -EINVAL; 869 } 870 871 return ret; 872 } 873 874 static void rk3x_i2c_adapt_div(struct rk3x_i2c *i2c, unsigned long clk_rate) 875 { 876 struct i2c_timings *t = &i2c->t; 877 struct rk3x_i2c_calced_timings calc; 878 u64 t_low_ns, t_high_ns; 879 unsigned long flags; 880 u32 val; 881 int ret; 882 883 ret = i2c->soc_data->calc_timings(clk_rate, t, &calc); 884 WARN_ONCE(ret != 0, "Could not reach SCL freq %u", t->bus_freq_hz); 885 886 clk_enable(i2c->pclk); 887 888 spin_lock_irqsave(&i2c->lock, flags); 889 val = i2c_readl(i2c, REG_CON); 890 val &= ~REG_CON_TUNING_MASK; 891 val |= calc.tuning; 892 i2c_writel(i2c, val, REG_CON); 893 i2c_writel(i2c, (calc.div_high << 16) | (calc.div_low & 0xffff), 894 REG_CLKDIV); 895 spin_unlock_irqrestore(&i2c->lock, flags); 896 897 clk_disable(i2c->pclk); 898 899 t_low_ns = div_u64(((u64)calc.div_low + 1) * 8 * 1000000000, clk_rate); 900 t_high_ns = div_u64(((u64)calc.div_high + 1) * 8 * 1000000000, 901 clk_rate); 902 dev_dbg(i2c->dev, 903 "CLK %lukhz, Req %uns, Act low %lluns high %lluns\n", 904 clk_rate / 1000, 905 1000000000 / t->bus_freq_hz, 906 t_low_ns, t_high_ns); 907 } 908 909 /** 910 * rk3x_i2c_clk_notifier_cb - Clock rate change callback 911 * @nb: Pointer to notifier block 912 * @event: Notification reason 913 * @data: Pointer to notification data object 914 * 915 * The callback checks whether a valid bus frequency can be generated after the 916 * change. If so, the change is acknowledged, otherwise the change is aborted. 917 * New dividers are written to the HW in the pre- or post change notification 918 * depending on the scaling direction. 919 * 920 * Code adapted from i2c-cadence.c. 921 * 922 * Return: NOTIFY_STOP if the rate change should be aborted, NOTIFY_OK 923 * to acknowledge the change, NOTIFY_DONE if the notification is 924 * considered irrelevant. 925 */ 926 static int rk3x_i2c_clk_notifier_cb(struct notifier_block *nb, unsigned long 927 event, void *data) 928 { 929 struct clk_notifier_data *ndata = data; 930 struct rk3x_i2c *i2c = container_of(nb, struct rk3x_i2c, clk_rate_nb); 931 struct rk3x_i2c_calced_timings calc; 932 933 switch (event) { 934 case PRE_RATE_CHANGE: 935 /* 936 * Try the calculation (but don't store the result) ahead of 937 * time to see if we need to block the clock change. Timings 938 * shouldn't actually take effect until rk3x_i2c_adapt_div(). 939 */ 940 if (i2c->soc_data->calc_timings(ndata->new_rate, &i2c->t, 941 &calc) != 0) 942 return NOTIFY_STOP; 943 944 /* scale up */ 945 if (ndata->new_rate > ndata->old_rate) 946 rk3x_i2c_adapt_div(i2c, ndata->new_rate); 947 948 return NOTIFY_OK; 949 case POST_RATE_CHANGE: 950 /* scale down */ 951 if (ndata->new_rate < ndata->old_rate) 952 rk3x_i2c_adapt_div(i2c, ndata->new_rate); 953 return NOTIFY_OK; 954 case ABORT_RATE_CHANGE: 955 /* scale up */ 956 if (ndata->new_rate > ndata->old_rate) 957 rk3x_i2c_adapt_div(i2c, ndata->old_rate); 958 return NOTIFY_OK; 959 default: 960 return NOTIFY_DONE; 961 } 962 } 963 964 /** 965 * rk3x_i2c_setup - Setup I2C registers for an I2C operation specified by msgs, num. 966 * @i2c: target controller data 967 * @msgs: I2C msgs to process 968 * @num: Number of msgs 969 * 970 * Must be called with i2c->lock held. 971 * 972 * Return: Number of I2C msgs processed or negative in case of error 973 */ 974 static int rk3x_i2c_setup(struct rk3x_i2c *i2c, struct i2c_msg *msgs, int num) 975 { 976 u32 addr = (msgs[0].addr & 0x7f) << 1; 977 int ret = 0; 978 979 /* 980 * The I2C adapter can issue a small (len < 4) write packet before 981 * reading. This speeds up SMBus-style register reads. 982 * The MRXADDR/MRXRADDR hold the slave address and the slave register 983 * address in this case. 984 */ 985 986 if (num >= 2 && msgs[0].len < 4 && 987 !(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD)) { 988 u32 reg_addr = 0; 989 int i; 990 991 dev_dbg(i2c->dev, "Combined write/read from addr 0x%x\n", 992 addr >> 1); 993 994 /* Fill MRXRADDR with the register address(es) */ 995 for (i = 0; i < msgs[0].len; ++i) { 996 reg_addr |= msgs[0].buf[i] << (i * 8); 997 reg_addr |= REG_MRXADDR_VALID(i); 998 } 999 1000 /* msgs[0] is handled by hw. */ 1001 i2c->msg = &msgs[1]; 1002 1003 i2c->mode = REG_CON_MOD_REGISTER_TX; 1004 1005 i2c_writel(i2c, addr | REG_MRXADDR_VALID(0), REG_MRXADDR); 1006 i2c_writel(i2c, reg_addr, REG_MRXRADDR); 1007 1008 ret = 2; 1009 } else { 1010 /* 1011 * We'll have to do it the boring way and process the msgs 1012 * one-by-one. 1013 */ 1014 1015 if (msgs[0].flags & I2C_M_RD) { 1016 addr |= 1; /* set read bit */ 1017 1018 /* 1019 * We have to transmit the slave addr first. Use 1020 * MOD_REGISTER_TX for that purpose. 1021 */ 1022 i2c->mode = REG_CON_MOD_REGISTER_TX; 1023 i2c_writel(i2c, addr | REG_MRXADDR_VALID(0), 1024 REG_MRXADDR); 1025 i2c_writel(i2c, 0, REG_MRXRADDR); 1026 } else { 1027 i2c->mode = REG_CON_MOD_TX; 1028 } 1029 1030 i2c->msg = &msgs[0]; 1031 1032 ret = 1; 1033 } 1034 1035 i2c->addr = msgs[0].addr; 1036 i2c->busy = true; 1037 i2c->state = STATE_START; 1038 i2c->processed = 0; 1039 i2c->error = 0; 1040 1041 rk3x_i2c_clean_ipd(i2c); 1042 1043 return ret; 1044 } 1045 1046 static int rk3x_i2c_wait_xfer_poll(struct rk3x_i2c *i2c) 1047 { 1048 ktime_t timeout = ktime_add_ms(ktime_get(), WAIT_TIMEOUT); 1049 1050 while (READ_ONCE(i2c->busy) && 1051 ktime_compare(ktime_get(), timeout) < 0) { 1052 udelay(5); 1053 rk3x_i2c_irq(0, i2c); 1054 } 1055 1056 return !i2c->busy; 1057 } 1058 1059 static int rk3x_i2c_xfer_common(struct i2c_adapter *adap, 1060 struct i2c_msg *msgs, int num, bool polling) 1061 { 1062 struct rk3x_i2c *i2c = (struct rk3x_i2c *)adap->algo_data; 1063 unsigned long timeout, flags; 1064 u32 val; 1065 int ret = 0; 1066 int i; 1067 1068 spin_lock_irqsave(&i2c->lock, flags); 1069 1070 clk_enable(i2c->clk); 1071 clk_enable(i2c->pclk); 1072 1073 i2c->is_last_msg = false; 1074 1075 /* 1076 * Process msgs. We can handle more than one message at once (see 1077 * rk3x_i2c_setup()). 1078 */ 1079 for (i = 0; i < num; i += ret) { 1080 ret = rk3x_i2c_setup(i2c, msgs + i, num - i); 1081 1082 if (ret < 0) { 1083 dev_err(i2c->dev, "rk3x_i2c_setup() failed\n"); 1084 break; 1085 } 1086 1087 if (i + ret >= num) 1088 i2c->is_last_msg = true; 1089 1090 spin_unlock_irqrestore(&i2c->lock, flags); 1091 1092 if (!polling) { 1093 rk3x_i2c_start(i2c); 1094 1095 timeout = wait_event_timeout(i2c->wait, !i2c->busy, 1096 msecs_to_jiffies(WAIT_TIMEOUT)); 1097 } else { 1098 disable_irq(i2c->irq); 1099 rk3x_i2c_start(i2c); 1100 1101 timeout = rk3x_i2c_wait_xfer_poll(i2c); 1102 1103 enable_irq(i2c->irq); 1104 } 1105 1106 spin_lock_irqsave(&i2c->lock, flags); 1107 1108 if (timeout == 0) { 1109 dev_err(i2c->dev, "timeout, ipd: 0x%02x, state: %d\n", 1110 i2c_readl(i2c, REG_IPD), i2c->state); 1111 1112 /* Force a STOP condition without interrupt */ 1113 i2c_writel(i2c, 0, REG_IEN); 1114 val = i2c_readl(i2c, REG_CON) & REG_CON_TUNING_MASK; 1115 val |= REG_CON_EN | REG_CON_STOP; 1116 i2c_writel(i2c, val, REG_CON); 1117 1118 i2c->state = STATE_IDLE; 1119 1120 ret = -ETIMEDOUT; 1121 break; 1122 } 1123 1124 if (i2c->error) { 1125 ret = i2c->error; 1126 break; 1127 } 1128 } 1129 1130 clk_disable(i2c->pclk); 1131 clk_disable(i2c->clk); 1132 1133 spin_unlock_irqrestore(&i2c->lock, flags); 1134 1135 return ret < 0 ? ret : num; 1136 } 1137 1138 static int rk3x_i2c_xfer(struct i2c_adapter *adap, 1139 struct i2c_msg *msgs, int num) 1140 { 1141 return rk3x_i2c_xfer_common(adap, msgs, num, false); 1142 } 1143 1144 static int rk3x_i2c_xfer_polling(struct i2c_adapter *adap, 1145 struct i2c_msg *msgs, int num) 1146 { 1147 return rk3x_i2c_xfer_common(adap, msgs, num, true); 1148 } 1149 1150 static __maybe_unused int rk3x_i2c_resume(struct device *dev) 1151 { 1152 struct rk3x_i2c *i2c = dev_get_drvdata(dev); 1153 1154 rk3x_i2c_adapt_div(i2c, clk_get_rate(i2c->clk)); 1155 1156 return 0; 1157 } 1158 1159 static u32 rk3x_i2c_func(struct i2c_adapter *adap) 1160 { 1161 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING; 1162 } 1163 1164 static const struct i2c_algorithm rk3x_i2c_algorithm = { 1165 .master_xfer = rk3x_i2c_xfer, 1166 .master_xfer_atomic = rk3x_i2c_xfer_polling, 1167 .functionality = rk3x_i2c_func, 1168 }; 1169 1170 static const struct rk3x_i2c_soc_data rv1108_soc_data = { 1171 .grf_offset = -1, 1172 .calc_timings = rk3x_i2c_v1_calc_timings, 1173 }; 1174 1175 static const struct rk3x_i2c_soc_data rv1126_soc_data = { 1176 .grf_offset = 0x118, 1177 .calc_timings = rk3x_i2c_v1_calc_timings, 1178 }; 1179 1180 static const struct rk3x_i2c_soc_data rk3066_soc_data = { 1181 .grf_offset = 0x154, 1182 .calc_timings = rk3x_i2c_v0_calc_timings, 1183 }; 1184 1185 static const struct rk3x_i2c_soc_data rk3188_soc_data = { 1186 .grf_offset = 0x0a4, 1187 .calc_timings = rk3x_i2c_v0_calc_timings, 1188 }; 1189 1190 static const struct rk3x_i2c_soc_data rk3228_soc_data = { 1191 .grf_offset = -1, 1192 .calc_timings = rk3x_i2c_v0_calc_timings, 1193 }; 1194 1195 static const struct rk3x_i2c_soc_data rk3288_soc_data = { 1196 .grf_offset = -1, 1197 .calc_timings = rk3x_i2c_v0_calc_timings, 1198 }; 1199 1200 static const struct rk3x_i2c_soc_data rk3399_soc_data = { 1201 .grf_offset = -1, 1202 .calc_timings = rk3x_i2c_v1_calc_timings, 1203 }; 1204 1205 static const struct of_device_id rk3x_i2c_match[] = { 1206 { 1207 .compatible = "rockchip,rv1108-i2c", 1208 .data = &rv1108_soc_data 1209 }, 1210 { 1211 .compatible = "rockchip,rv1126-i2c", 1212 .data = &rv1126_soc_data 1213 }, 1214 { 1215 .compatible = "rockchip,rk3066-i2c", 1216 .data = &rk3066_soc_data 1217 }, 1218 { 1219 .compatible = "rockchip,rk3188-i2c", 1220 .data = &rk3188_soc_data 1221 }, 1222 { 1223 .compatible = "rockchip,rk3228-i2c", 1224 .data = &rk3228_soc_data 1225 }, 1226 { 1227 .compatible = "rockchip,rk3288-i2c", 1228 .data = &rk3288_soc_data 1229 }, 1230 { 1231 .compatible = "rockchip,rk3399-i2c", 1232 .data = &rk3399_soc_data 1233 }, 1234 {}, 1235 }; 1236 MODULE_DEVICE_TABLE(of, rk3x_i2c_match); 1237 1238 static int rk3x_i2c_probe(struct platform_device *pdev) 1239 { 1240 struct device_node *np = pdev->dev.of_node; 1241 const struct of_device_id *match; 1242 struct rk3x_i2c *i2c; 1243 int ret = 0; 1244 int bus_nr; 1245 u32 value; 1246 int irq; 1247 unsigned long clk_rate; 1248 1249 i2c = devm_kzalloc(&pdev->dev, sizeof(struct rk3x_i2c), GFP_KERNEL); 1250 if (!i2c) 1251 return -ENOMEM; 1252 1253 match = of_match_node(rk3x_i2c_match, np); 1254 i2c->soc_data = match->data; 1255 1256 /* use common interface to get I2C timing properties */ 1257 i2c_parse_fw_timings(&pdev->dev, &i2c->t, true); 1258 1259 strscpy(i2c->adap.name, "rk3x-i2c", sizeof(i2c->adap.name)); 1260 i2c->adap.owner = THIS_MODULE; 1261 i2c->adap.algo = &rk3x_i2c_algorithm; 1262 i2c->adap.retries = 3; 1263 i2c->adap.dev.of_node = np; 1264 i2c->adap.algo_data = i2c; 1265 i2c->adap.dev.parent = &pdev->dev; 1266 1267 i2c->dev = &pdev->dev; 1268 1269 spin_lock_init(&i2c->lock); 1270 init_waitqueue_head(&i2c->wait); 1271 1272 i2c->regs = devm_platform_ioremap_resource(pdev, 0); 1273 if (IS_ERR(i2c->regs)) 1274 return PTR_ERR(i2c->regs); 1275 1276 /* Try to set the I2C adapter number from dt */ 1277 bus_nr = of_alias_get_id(np, "i2c"); 1278 1279 /* 1280 * Switch to new interface if the SoC also offers the old one. 1281 * The control bit is located in the GRF register space. 1282 */ 1283 if (i2c->soc_data->grf_offset >= 0) { 1284 struct regmap *grf; 1285 1286 grf = syscon_regmap_lookup_by_phandle(np, "rockchip,grf"); 1287 if (IS_ERR(grf)) { 1288 dev_err(&pdev->dev, 1289 "rk3x-i2c needs 'rockchip,grf' property\n"); 1290 return PTR_ERR(grf); 1291 } 1292 1293 if (bus_nr < 0) { 1294 dev_err(&pdev->dev, "rk3x-i2c needs i2cX alias"); 1295 return -EINVAL; 1296 } 1297 1298 /* 27+i: write mask, 11+i: value */ 1299 value = BIT(27 + bus_nr) | BIT(11 + bus_nr); 1300 1301 ret = regmap_write(grf, i2c->soc_data->grf_offset, value); 1302 if (ret != 0) { 1303 dev_err(i2c->dev, "Could not write to GRF: %d\n", ret); 1304 return ret; 1305 } 1306 } 1307 1308 /* IRQ setup */ 1309 irq = platform_get_irq(pdev, 0); 1310 if (irq < 0) 1311 return irq; 1312 1313 ret = devm_request_irq(&pdev->dev, irq, rk3x_i2c_irq, 1314 0, dev_name(&pdev->dev), i2c); 1315 if (ret < 0) { 1316 dev_err(&pdev->dev, "cannot request IRQ\n"); 1317 return ret; 1318 } 1319 1320 i2c->irq = irq; 1321 1322 platform_set_drvdata(pdev, i2c); 1323 1324 if (i2c->soc_data->calc_timings == rk3x_i2c_v0_calc_timings) { 1325 /* Only one clock to use for bus clock and peripheral clock */ 1326 i2c->clk = devm_clk_get(&pdev->dev, NULL); 1327 i2c->pclk = i2c->clk; 1328 } else { 1329 i2c->clk = devm_clk_get(&pdev->dev, "i2c"); 1330 i2c->pclk = devm_clk_get(&pdev->dev, "pclk"); 1331 } 1332 1333 if (IS_ERR(i2c->clk)) 1334 return dev_err_probe(&pdev->dev, PTR_ERR(i2c->clk), 1335 "Can't get bus clk\n"); 1336 1337 if (IS_ERR(i2c->pclk)) 1338 return dev_err_probe(&pdev->dev, PTR_ERR(i2c->pclk), 1339 "Can't get periph clk\n"); 1340 1341 ret = clk_prepare(i2c->clk); 1342 if (ret < 0) { 1343 dev_err(&pdev->dev, "Can't prepare bus clk: %d\n", ret); 1344 return ret; 1345 } 1346 ret = clk_prepare(i2c->pclk); 1347 if (ret < 0) { 1348 dev_err(&pdev->dev, "Can't prepare periph clock: %d\n", ret); 1349 goto err_clk; 1350 } 1351 1352 i2c->clk_rate_nb.notifier_call = rk3x_i2c_clk_notifier_cb; 1353 ret = clk_notifier_register(i2c->clk, &i2c->clk_rate_nb); 1354 if (ret != 0) { 1355 dev_err(&pdev->dev, "Unable to register clock notifier\n"); 1356 goto err_pclk; 1357 } 1358 1359 ret = clk_enable(i2c->clk); 1360 if (ret < 0) { 1361 dev_err(&pdev->dev, "Can't enable bus clk: %d\n", ret); 1362 goto err_clk_notifier; 1363 } 1364 1365 clk_rate = clk_get_rate(i2c->clk); 1366 rk3x_i2c_adapt_div(i2c, clk_rate); 1367 clk_disable(i2c->clk); 1368 1369 ret = i2c_add_adapter(&i2c->adap); 1370 if (ret < 0) 1371 goto err_clk_notifier; 1372 1373 return 0; 1374 1375 err_clk_notifier: 1376 clk_notifier_unregister(i2c->clk, &i2c->clk_rate_nb); 1377 err_pclk: 1378 clk_unprepare(i2c->pclk); 1379 err_clk: 1380 clk_unprepare(i2c->clk); 1381 return ret; 1382 } 1383 1384 static void rk3x_i2c_remove(struct platform_device *pdev) 1385 { 1386 struct rk3x_i2c *i2c = platform_get_drvdata(pdev); 1387 1388 i2c_del_adapter(&i2c->adap); 1389 1390 clk_notifier_unregister(i2c->clk, &i2c->clk_rate_nb); 1391 clk_unprepare(i2c->pclk); 1392 clk_unprepare(i2c->clk); 1393 } 1394 1395 static SIMPLE_DEV_PM_OPS(rk3x_i2c_pm_ops, NULL, rk3x_i2c_resume); 1396 1397 static struct platform_driver rk3x_i2c_driver = { 1398 .probe = rk3x_i2c_probe, 1399 .remove_new = rk3x_i2c_remove, 1400 .driver = { 1401 .name = "rk3x-i2c", 1402 .of_match_table = rk3x_i2c_match, 1403 .pm = &rk3x_i2c_pm_ops, 1404 }, 1405 }; 1406 1407 module_platform_driver(rk3x_i2c_driver); 1408 1409 MODULE_DESCRIPTION("Rockchip RK3xxx I2C Bus driver"); 1410 MODULE_AUTHOR("Max Schwarz <max.schwarz@online.de>"); 1411 MODULE_LICENSE("GPL v2"); 1412