1 /* 2 * Copyright (c) 2014 MediaTek Inc. 3 * Author: Xudong Chen <xudong.chen@mediatek.com> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 */ 14 15 #include <linux/clk.h> 16 #include <linux/completion.h> 17 #include <linux/delay.h> 18 #include <linux/device.h> 19 #include <linux/dma-mapping.h> 20 #include <linux/err.h> 21 #include <linux/errno.h> 22 #include <linux/i2c.h> 23 #include <linux/init.h> 24 #include <linux/interrupt.h> 25 #include <linux/io.h> 26 #include <linux/kernel.h> 27 #include <linux/mm.h> 28 #include <linux/module.h> 29 #include <linux/of_address.h> 30 #include <linux/of_irq.h> 31 #include <linux/platform_device.h> 32 #include <linux/scatterlist.h> 33 #include <linux/sched.h> 34 #include <linux/slab.h> 35 36 #define I2C_RS_TRANSFER (1 << 4) 37 #define I2C_HS_NACKERR (1 << 2) 38 #define I2C_ACKERR (1 << 1) 39 #define I2C_TRANSAC_COMP (1 << 0) 40 #define I2C_TRANSAC_START (1 << 0) 41 #define I2C_RS_MUL_CNFG (1 << 15) 42 #define I2C_RS_MUL_TRIG (1 << 14) 43 #define I2C_DCM_DISABLE 0x0000 44 #define I2C_IO_CONFIG_OPEN_DRAIN 0x0003 45 #define I2C_IO_CONFIG_PUSH_PULL 0x0000 46 #define I2C_SOFT_RST 0x0001 47 #define I2C_FIFO_ADDR_CLR 0x0001 48 #define I2C_DELAY_LEN 0x0002 49 #define I2C_ST_START_CON 0x8001 50 #define I2C_FS_START_CON 0x1800 51 #define I2C_TIME_CLR_VALUE 0x0000 52 #define I2C_TIME_DEFAULT_VALUE 0x0003 53 #define I2C_FS_TIME_INIT_VALUE 0x1303 54 #define I2C_WRRD_TRANAC_VALUE 0x0002 55 #define I2C_RD_TRANAC_VALUE 0x0001 56 57 #define I2C_DMA_CON_TX 0x0000 58 #define I2C_DMA_CON_RX 0x0001 59 #define I2C_DMA_START_EN 0x0001 60 #define I2C_DMA_INT_FLAG_NONE 0x0000 61 #define I2C_DMA_CLR_FLAG 0x0000 62 #define I2C_DMA_HARD_RST 0x0002 63 64 #define I2C_DEFAULT_SPEED 100000 /* hz */ 65 #define MAX_FS_MODE_SPEED 400000 66 #define MAX_HS_MODE_SPEED 3400000 67 #define MAX_SAMPLE_CNT_DIV 8 68 #define MAX_STEP_CNT_DIV 64 69 #define MAX_HS_STEP_CNT_DIV 8 70 71 #define I2C_CONTROL_RS (0x1 << 1) 72 #define I2C_CONTROL_DMA_EN (0x1 << 2) 73 #define I2C_CONTROL_CLK_EXT_EN (0x1 << 3) 74 #define I2C_CONTROL_DIR_CHANGE (0x1 << 4) 75 #define I2C_CONTROL_ACKERR_DET_EN (0x1 << 5) 76 #define I2C_CONTROL_TRANSFER_LEN_CHANGE (0x1 << 6) 77 #define I2C_CONTROL_WRAPPER (0x1 << 0) 78 79 #define I2C_DRV_NAME "i2c-mt65xx" 80 81 enum DMA_REGS_OFFSET { 82 OFFSET_INT_FLAG = 0x0, 83 OFFSET_INT_EN = 0x04, 84 OFFSET_EN = 0x08, 85 OFFSET_RST = 0x0c, 86 OFFSET_CON = 0x18, 87 OFFSET_TX_MEM_ADDR = 0x1c, 88 OFFSET_RX_MEM_ADDR = 0x20, 89 OFFSET_TX_LEN = 0x24, 90 OFFSET_RX_LEN = 0x28, 91 }; 92 93 enum i2c_trans_st_rs { 94 I2C_TRANS_STOP = 0, 95 I2C_TRANS_REPEATED_START, 96 }; 97 98 enum mtk_trans_op { 99 I2C_MASTER_WR = 1, 100 I2C_MASTER_RD, 101 I2C_MASTER_WRRD, 102 }; 103 104 enum I2C_REGS_OFFSET { 105 OFFSET_DATA_PORT = 0x0, 106 OFFSET_SLAVE_ADDR = 0x04, 107 OFFSET_INTR_MASK = 0x08, 108 OFFSET_INTR_STAT = 0x0c, 109 OFFSET_CONTROL = 0x10, 110 OFFSET_TRANSFER_LEN = 0x14, 111 OFFSET_TRANSAC_LEN = 0x18, 112 OFFSET_DELAY_LEN = 0x1c, 113 OFFSET_TIMING = 0x20, 114 OFFSET_START = 0x24, 115 OFFSET_EXT_CONF = 0x28, 116 OFFSET_FIFO_STAT = 0x30, 117 OFFSET_FIFO_THRESH = 0x34, 118 OFFSET_FIFO_ADDR_CLR = 0x38, 119 OFFSET_IO_CONFIG = 0x40, 120 OFFSET_RSV_DEBUG = 0x44, 121 OFFSET_HS = 0x48, 122 OFFSET_SOFTRESET = 0x50, 123 OFFSET_DCM_EN = 0x54, 124 OFFSET_PATH_DIR = 0x60, 125 OFFSET_DEBUGSTAT = 0x64, 126 OFFSET_DEBUGCTRL = 0x68, 127 OFFSET_TRANSFER_LEN_AUX = 0x6c, 128 }; 129 130 struct mtk_i2c_compatible { 131 const struct i2c_adapter_quirks *quirks; 132 unsigned char pmic_i2c: 1; 133 unsigned char dcm: 1; 134 unsigned char auto_restart: 1; 135 }; 136 137 struct mtk_i2c { 138 struct i2c_adapter adap; /* i2c host adapter */ 139 struct device *dev; 140 struct completion msg_complete; 141 142 /* set in i2c probe */ 143 void __iomem *base; /* i2c base addr */ 144 void __iomem *pdmabase; /* dma base address*/ 145 struct clk *clk_main; /* main clock for i2c bus */ 146 struct clk *clk_dma; /* DMA clock for i2c via DMA */ 147 struct clk *clk_pmic; /* PMIC clock for i2c from PMIC */ 148 bool have_pmic; /* can use i2c pins from PMIC */ 149 bool use_push_pull; /* IO config push-pull mode */ 150 151 u16 irq_stat; /* interrupt status */ 152 unsigned int speed_hz; /* The speed in transfer */ 153 enum mtk_trans_op op; 154 u16 timing_reg; 155 u16 high_speed_reg; 156 const struct mtk_i2c_compatible *dev_comp; 157 }; 158 159 static const struct i2c_adapter_quirks mt6577_i2c_quirks = { 160 .flags = I2C_AQ_COMB_WRITE_THEN_READ, 161 .max_num_msgs = 1, 162 .max_write_len = 255, 163 .max_read_len = 255, 164 .max_comb_1st_msg_len = 255, 165 .max_comb_2nd_msg_len = 31, 166 }; 167 168 static const struct i2c_adapter_quirks mt8173_i2c_quirks = { 169 .max_num_msgs = 65535, 170 .max_write_len = 65535, 171 .max_read_len = 65535, 172 .max_comb_1st_msg_len = 65535, 173 .max_comb_2nd_msg_len = 65535, 174 }; 175 176 static const struct mtk_i2c_compatible mt6577_compat = { 177 .quirks = &mt6577_i2c_quirks, 178 .pmic_i2c = 0, 179 .dcm = 1, 180 .auto_restart = 0, 181 }; 182 183 static const struct mtk_i2c_compatible mt6589_compat = { 184 .quirks = &mt6577_i2c_quirks, 185 .pmic_i2c = 1, 186 .dcm = 0, 187 .auto_restart = 0, 188 }; 189 190 static const struct mtk_i2c_compatible mt8173_compat = { 191 .quirks = &mt8173_i2c_quirks, 192 .pmic_i2c = 0, 193 .dcm = 1, 194 .auto_restart = 1, 195 }; 196 197 static const struct of_device_id mtk_i2c_of_match[] = { 198 { .compatible = "mediatek,mt6577-i2c", .data = &mt6577_compat }, 199 { .compatible = "mediatek,mt6589-i2c", .data = &mt6589_compat }, 200 { .compatible = "mediatek,mt8173-i2c", .data = &mt8173_compat }, 201 {} 202 }; 203 MODULE_DEVICE_TABLE(of, mtk_i2c_of_match); 204 205 static int mtk_i2c_clock_enable(struct mtk_i2c *i2c) 206 { 207 int ret; 208 209 ret = clk_prepare_enable(i2c->clk_dma); 210 if (ret) 211 return ret; 212 213 ret = clk_prepare_enable(i2c->clk_main); 214 if (ret) 215 goto err_main; 216 217 if (i2c->have_pmic) { 218 ret = clk_prepare_enable(i2c->clk_pmic); 219 if (ret) 220 goto err_pmic; 221 } 222 return 0; 223 224 err_pmic: 225 clk_disable_unprepare(i2c->clk_main); 226 err_main: 227 clk_disable_unprepare(i2c->clk_dma); 228 229 return ret; 230 } 231 232 static void mtk_i2c_clock_disable(struct mtk_i2c *i2c) 233 { 234 if (i2c->have_pmic) 235 clk_disable_unprepare(i2c->clk_pmic); 236 237 clk_disable_unprepare(i2c->clk_main); 238 clk_disable_unprepare(i2c->clk_dma); 239 } 240 241 static void mtk_i2c_init_hw(struct mtk_i2c *i2c) 242 { 243 u16 control_reg; 244 245 writew(I2C_SOFT_RST, i2c->base + OFFSET_SOFTRESET); 246 247 /* Set ioconfig */ 248 if (i2c->use_push_pull) 249 writew(I2C_IO_CONFIG_PUSH_PULL, i2c->base + OFFSET_IO_CONFIG); 250 else 251 writew(I2C_IO_CONFIG_OPEN_DRAIN, i2c->base + OFFSET_IO_CONFIG); 252 253 if (i2c->dev_comp->dcm) 254 writew(I2C_DCM_DISABLE, i2c->base + OFFSET_DCM_EN); 255 256 writew(i2c->timing_reg, i2c->base + OFFSET_TIMING); 257 writew(i2c->high_speed_reg, i2c->base + OFFSET_HS); 258 259 /* If use i2c pin from PMIC mt6397 side, need set PATH_DIR first */ 260 if (i2c->have_pmic) 261 writew(I2C_CONTROL_WRAPPER, i2c->base + OFFSET_PATH_DIR); 262 263 control_reg = I2C_CONTROL_ACKERR_DET_EN | 264 I2C_CONTROL_CLK_EXT_EN | I2C_CONTROL_DMA_EN; 265 writew(control_reg, i2c->base + OFFSET_CONTROL); 266 writew(I2C_DELAY_LEN, i2c->base + OFFSET_DELAY_LEN); 267 268 writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST); 269 udelay(50); 270 writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST); 271 } 272 273 /* 274 * Calculate i2c port speed 275 * 276 * Hardware design: 277 * i2c_bus_freq = parent_clk / (clock_div * 2 * sample_cnt * step_cnt) 278 * clock_div: fixed in hardware, but may be various in different SoCs 279 * 280 * The calculation want to pick the highest bus frequency that is still 281 * less than or equal to i2c->speed_hz. The calculation try to get 282 * sample_cnt and step_cn 283 */ 284 static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk, 285 unsigned int clock_div) 286 { 287 unsigned int clk_src; 288 unsigned int step_cnt; 289 unsigned int sample_cnt; 290 unsigned int max_step_cnt; 291 unsigned int target_speed; 292 unsigned int base_sample_cnt = MAX_SAMPLE_CNT_DIV; 293 unsigned int base_step_cnt; 294 unsigned int opt_div; 295 unsigned int best_mul; 296 unsigned int cnt_mul; 297 298 clk_src = parent_clk / clock_div; 299 target_speed = i2c->speed_hz; 300 301 if (target_speed > MAX_HS_MODE_SPEED) 302 target_speed = MAX_HS_MODE_SPEED; 303 304 if (target_speed > MAX_FS_MODE_SPEED) 305 max_step_cnt = MAX_HS_STEP_CNT_DIV; 306 else 307 max_step_cnt = MAX_STEP_CNT_DIV; 308 309 base_step_cnt = max_step_cnt; 310 /* Find the best combination */ 311 opt_div = DIV_ROUND_UP(clk_src >> 1, target_speed); 312 best_mul = MAX_SAMPLE_CNT_DIV * max_step_cnt; 313 314 /* Search for the best pair (sample_cnt, step_cnt) with 315 * 0 < sample_cnt < MAX_SAMPLE_CNT_DIV 316 * 0 < step_cnt < max_step_cnt 317 * sample_cnt * step_cnt >= opt_div 318 * optimizing for sample_cnt * step_cnt being minimal 319 */ 320 for (sample_cnt = 1; sample_cnt <= MAX_SAMPLE_CNT_DIV; sample_cnt++) { 321 step_cnt = DIV_ROUND_UP(opt_div, sample_cnt); 322 cnt_mul = step_cnt * sample_cnt; 323 if (step_cnt > max_step_cnt) 324 continue; 325 326 if (cnt_mul < best_mul) { 327 best_mul = cnt_mul; 328 base_sample_cnt = sample_cnt; 329 base_step_cnt = step_cnt; 330 if (best_mul == opt_div) 331 break; 332 } 333 } 334 335 sample_cnt = base_sample_cnt; 336 step_cnt = base_step_cnt; 337 338 if ((clk_src / (2 * sample_cnt * step_cnt)) > target_speed) { 339 /* In this case, hardware can't support such 340 * low i2c_bus_freq 341 */ 342 dev_dbg(i2c->dev, "Unsupported speed (%uhz)\n", target_speed); 343 return -EINVAL; 344 } 345 346 step_cnt--; 347 sample_cnt--; 348 349 if (target_speed > MAX_FS_MODE_SPEED) { 350 /* Set the high speed mode register */ 351 i2c->timing_reg = I2C_FS_TIME_INIT_VALUE; 352 i2c->high_speed_reg = I2C_TIME_DEFAULT_VALUE | 353 (sample_cnt << 12) | (step_cnt << 8); 354 } else { 355 i2c->timing_reg = (sample_cnt << 8) | (step_cnt << 0); 356 /* Disable the high speed transaction */ 357 i2c->high_speed_reg = I2C_TIME_CLR_VALUE; 358 } 359 360 return 0; 361 } 362 363 static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, 364 int num, int left_num) 365 { 366 u16 addr_reg; 367 u16 start_reg; 368 u16 control_reg; 369 u16 restart_flag = 0; 370 dma_addr_t rpaddr = 0; 371 dma_addr_t wpaddr = 0; 372 int ret; 373 374 i2c->irq_stat = 0; 375 376 if (i2c->dev_comp->auto_restart) 377 restart_flag = I2C_RS_TRANSFER; 378 379 reinit_completion(&i2c->msg_complete); 380 381 control_reg = readw(i2c->base + OFFSET_CONTROL) & 382 ~(I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS); 383 if ((i2c->speed_hz > 400000) || (left_num >= 1)) 384 control_reg |= I2C_CONTROL_RS; 385 386 if (i2c->op == I2C_MASTER_WRRD) 387 control_reg |= I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS; 388 389 writew(control_reg, i2c->base + OFFSET_CONTROL); 390 391 /* set start condition */ 392 if (i2c->speed_hz <= 100000) 393 writew(I2C_ST_START_CON, i2c->base + OFFSET_EXT_CONF); 394 else 395 writew(I2C_FS_START_CON, i2c->base + OFFSET_EXT_CONF); 396 397 addr_reg = msgs->addr << 1; 398 if (i2c->op == I2C_MASTER_RD) 399 addr_reg |= 0x1; 400 401 writew(addr_reg, i2c->base + OFFSET_SLAVE_ADDR); 402 403 /* Clear interrupt status */ 404 writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR | 405 I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_STAT); 406 writew(I2C_FIFO_ADDR_CLR, i2c->base + OFFSET_FIFO_ADDR_CLR); 407 408 /* Enable interrupt */ 409 writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR | 410 I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_MASK); 411 412 /* Set transfer and transaction len */ 413 if (i2c->op == I2C_MASTER_WRRD) { 414 writew(msgs->len | ((msgs + 1)->len) << 8, 415 i2c->base + OFFSET_TRANSFER_LEN); 416 writew(I2C_WRRD_TRANAC_VALUE, i2c->base + OFFSET_TRANSAC_LEN); 417 } else { 418 writew(msgs->len, i2c->base + OFFSET_TRANSFER_LEN); 419 writew(num, i2c->base + OFFSET_TRANSAC_LEN); 420 } 421 422 /* Prepare buffer data to start transfer */ 423 if (i2c->op == I2C_MASTER_RD) { 424 writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG); 425 writel(I2C_DMA_CON_RX, i2c->pdmabase + OFFSET_CON); 426 rpaddr = dma_map_single(i2c->dev, msgs->buf, 427 msgs->len, DMA_FROM_DEVICE); 428 if (dma_mapping_error(i2c->dev, rpaddr)) 429 return -ENOMEM; 430 writel((u32)rpaddr, i2c->pdmabase + OFFSET_RX_MEM_ADDR); 431 writel(msgs->len, i2c->pdmabase + OFFSET_RX_LEN); 432 } else if (i2c->op == I2C_MASTER_WR) { 433 writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG); 434 writel(I2C_DMA_CON_TX, i2c->pdmabase + OFFSET_CON); 435 wpaddr = dma_map_single(i2c->dev, msgs->buf, 436 msgs->len, DMA_TO_DEVICE); 437 if (dma_mapping_error(i2c->dev, wpaddr)) 438 return -ENOMEM; 439 writel((u32)wpaddr, i2c->pdmabase + OFFSET_TX_MEM_ADDR); 440 writel(msgs->len, i2c->pdmabase + OFFSET_TX_LEN); 441 } else { 442 writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_INT_FLAG); 443 writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_CON); 444 wpaddr = dma_map_single(i2c->dev, msgs->buf, 445 msgs->len, DMA_TO_DEVICE); 446 if (dma_mapping_error(i2c->dev, wpaddr)) 447 return -ENOMEM; 448 rpaddr = dma_map_single(i2c->dev, (msgs + 1)->buf, 449 (msgs + 1)->len, 450 DMA_FROM_DEVICE); 451 if (dma_mapping_error(i2c->dev, rpaddr)) { 452 dma_unmap_single(i2c->dev, wpaddr, 453 msgs->len, DMA_TO_DEVICE); 454 return -ENOMEM; 455 } 456 writel((u32)wpaddr, i2c->pdmabase + OFFSET_TX_MEM_ADDR); 457 writel((u32)rpaddr, i2c->pdmabase + OFFSET_RX_MEM_ADDR); 458 writel(msgs->len, i2c->pdmabase + OFFSET_TX_LEN); 459 writel((msgs + 1)->len, i2c->pdmabase + OFFSET_RX_LEN); 460 } 461 462 writel(I2C_DMA_START_EN, i2c->pdmabase + OFFSET_EN); 463 464 if (!i2c->dev_comp->auto_restart) { 465 start_reg = I2C_TRANSAC_START; 466 } else { 467 start_reg = I2C_TRANSAC_START | I2C_RS_MUL_TRIG; 468 if (left_num >= 1) 469 start_reg |= I2C_RS_MUL_CNFG; 470 } 471 writew(start_reg, i2c->base + OFFSET_START); 472 473 ret = wait_for_completion_timeout(&i2c->msg_complete, 474 i2c->adap.timeout); 475 476 /* Clear interrupt mask */ 477 writew(~(restart_flag | I2C_HS_NACKERR | I2C_ACKERR | 478 I2C_TRANSAC_COMP), i2c->base + OFFSET_INTR_MASK); 479 480 if (i2c->op == I2C_MASTER_WR) { 481 dma_unmap_single(i2c->dev, wpaddr, 482 msgs->len, DMA_TO_DEVICE); 483 } else if (i2c->op == I2C_MASTER_RD) { 484 dma_unmap_single(i2c->dev, rpaddr, 485 msgs->len, DMA_FROM_DEVICE); 486 } else { 487 dma_unmap_single(i2c->dev, wpaddr, msgs->len, 488 DMA_TO_DEVICE); 489 dma_unmap_single(i2c->dev, rpaddr, (msgs + 1)->len, 490 DMA_FROM_DEVICE); 491 } 492 493 if (ret == 0) { 494 dev_dbg(i2c->dev, "addr: %x, transfer timeout\n", msgs->addr); 495 mtk_i2c_init_hw(i2c); 496 return -ETIMEDOUT; 497 } 498 499 completion_done(&i2c->msg_complete); 500 501 if (i2c->irq_stat & (I2C_HS_NACKERR | I2C_ACKERR)) { 502 dev_dbg(i2c->dev, "addr: %x, transfer ACK error\n", msgs->addr); 503 mtk_i2c_init_hw(i2c); 504 return -ENXIO; 505 } 506 507 return 0; 508 } 509 510 static int mtk_i2c_transfer(struct i2c_adapter *adap, 511 struct i2c_msg msgs[], int num) 512 { 513 int ret; 514 int left_num = num; 515 struct mtk_i2c *i2c = i2c_get_adapdata(adap); 516 517 ret = mtk_i2c_clock_enable(i2c); 518 if (ret) 519 return ret; 520 521 while (left_num--) { 522 if (!msgs->buf) { 523 dev_dbg(i2c->dev, "data buffer is NULL.\n"); 524 ret = -EINVAL; 525 goto err_exit; 526 } 527 528 if (msgs->flags & I2C_M_RD) 529 i2c->op = I2C_MASTER_RD; 530 else 531 i2c->op = I2C_MASTER_WR; 532 533 if (!i2c->dev_comp->auto_restart) { 534 if (num > 1) { 535 /* combined two messages into one transaction */ 536 i2c->op = I2C_MASTER_WRRD; 537 left_num--; 538 } 539 } 540 541 /* always use DMA mode. */ 542 ret = mtk_i2c_do_transfer(i2c, msgs, num, left_num); 543 if (ret < 0) 544 goto err_exit; 545 546 msgs++; 547 } 548 /* the return value is number of executed messages */ 549 ret = num; 550 551 err_exit: 552 mtk_i2c_clock_disable(i2c); 553 return ret; 554 } 555 556 static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id) 557 { 558 struct mtk_i2c *i2c = dev_id; 559 u16 restart_flag = 0; 560 u16 intr_stat; 561 562 if (i2c->dev_comp->auto_restart) 563 restart_flag = I2C_RS_TRANSFER; 564 565 intr_stat = readw(i2c->base + OFFSET_INTR_STAT); 566 writew(intr_stat, i2c->base + OFFSET_INTR_STAT); 567 568 /* 569 * when occurs ack error, i2c controller generate two interrupts 570 * first is the ack error interrupt, then the complete interrupt 571 * i2c->irq_stat need keep the two interrupt value. 572 */ 573 i2c->irq_stat |= intr_stat; 574 if (i2c->irq_stat & (I2C_TRANSAC_COMP | restart_flag)) 575 complete(&i2c->msg_complete); 576 577 return IRQ_HANDLED; 578 } 579 580 static u32 mtk_i2c_functionality(struct i2c_adapter *adap) 581 { 582 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; 583 } 584 585 static const struct i2c_algorithm mtk_i2c_algorithm = { 586 .master_xfer = mtk_i2c_transfer, 587 .functionality = mtk_i2c_functionality, 588 }; 589 590 static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c, 591 unsigned int *clk_src_div) 592 { 593 int ret; 594 595 ret = of_property_read_u32(np, "clock-frequency", &i2c->speed_hz); 596 if (ret < 0) 597 i2c->speed_hz = I2C_DEFAULT_SPEED; 598 599 ret = of_property_read_u32(np, "clock-div", clk_src_div); 600 if (ret < 0) 601 return ret; 602 603 if (*clk_src_div == 0) 604 return -EINVAL; 605 606 i2c->have_pmic = of_property_read_bool(np, "mediatek,have-pmic"); 607 i2c->use_push_pull = 608 of_property_read_bool(np, "mediatek,use-push-pull"); 609 610 return 0; 611 } 612 613 static int mtk_i2c_probe(struct platform_device *pdev) 614 { 615 const struct of_device_id *of_id; 616 int ret = 0; 617 struct mtk_i2c *i2c; 618 struct clk *clk; 619 unsigned int clk_src_div; 620 struct resource *res; 621 int irq; 622 623 i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL); 624 if (!i2c) 625 return -ENOMEM; 626 627 ret = mtk_i2c_parse_dt(pdev->dev.of_node, i2c, &clk_src_div); 628 if (ret) 629 return -EINVAL; 630 631 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 632 i2c->base = devm_ioremap_resource(&pdev->dev, res); 633 if (IS_ERR(i2c->base)) 634 return PTR_ERR(i2c->base); 635 636 res = platform_get_resource(pdev, IORESOURCE_MEM, 1); 637 i2c->pdmabase = devm_ioremap_resource(&pdev->dev, res); 638 if (IS_ERR(i2c->pdmabase)) 639 return PTR_ERR(i2c->pdmabase); 640 641 irq = platform_get_irq(pdev, 0); 642 if (irq <= 0) 643 return irq; 644 645 init_completion(&i2c->msg_complete); 646 647 of_id = of_match_node(mtk_i2c_of_match, pdev->dev.of_node); 648 if (!of_id) 649 return -EINVAL; 650 651 i2c->dev_comp = of_id->data; 652 i2c->adap.dev.of_node = pdev->dev.of_node; 653 i2c->dev = &pdev->dev; 654 i2c->adap.dev.parent = &pdev->dev; 655 i2c->adap.owner = THIS_MODULE; 656 i2c->adap.algo = &mtk_i2c_algorithm; 657 i2c->adap.quirks = i2c->dev_comp->quirks; 658 i2c->adap.timeout = 2 * HZ; 659 i2c->adap.retries = 1; 660 661 if (i2c->have_pmic && !i2c->dev_comp->pmic_i2c) 662 return -EINVAL; 663 664 i2c->clk_main = devm_clk_get(&pdev->dev, "main"); 665 if (IS_ERR(i2c->clk_main)) { 666 dev_err(&pdev->dev, "cannot get main clock\n"); 667 return PTR_ERR(i2c->clk_main); 668 } 669 670 i2c->clk_dma = devm_clk_get(&pdev->dev, "dma"); 671 if (IS_ERR(i2c->clk_dma)) { 672 dev_err(&pdev->dev, "cannot get dma clock\n"); 673 return PTR_ERR(i2c->clk_dma); 674 } 675 676 clk = i2c->clk_main; 677 if (i2c->have_pmic) { 678 i2c->clk_pmic = devm_clk_get(&pdev->dev, "pmic"); 679 if (IS_ERR(i2c->clk_pmic)) { 680 dev_err(&pdev->dev, "cannot get pmic clock\n"); 681 return PTR_ERR(i2c->clk_pmic); 682 } 683 clk = i2c->clk_pmic; 684 } 685 686 strlcpy(i2c->adap.name, I2C_DRV_NAME, sizeof(i2c->adap.name)); 687 688 ret = mtk_i2c_set_speed(i2c, clk_get_rate(clk), clk_src_div); 689 if (ret) { 690 dev_err(&pdev->dev, "Failed to set the speed.\n"); 691 return -EINVAL; 692 } 693 694 ret = mtk_i2c_clock_enable(i2c); 695 if (ret) { 696 dev_err(&pdev->dev, "clock enable failed!\n"); 697 return ret; 698 } 699 mtk_i2c_init_hw(i2c); 700 mtk_i2c_clock_disable(i2c); 701 702 ret = devm_request_irq(&pdev->dev, irq, mtk_i2c_irq, 703 IRQF_TRIGGER_NONE, I2C_DRV_NAME, i2c); 704 if (ret < 0) { 705 dev_err(&pdev->dev, 706 "Request I2C IRQ %d fail\n", irq); 707 return ret; 708 } 709 710 i2c_set_adapdata(&i2c->adap, i2c); 711 ret = i2c_add_adapter(&i2c->adap); 712 if (ret) { 713 dev_err(&pdev->dev, "Failed to add i2c bus to i2c core\n"); 714 return ret; 715 } 716 717 platform_set_drvdata(pdev, i2c); 718 719 return 0; 720 } 721 722 static int mtk_i2c_remove(struct platform_device *pdev) 723 { 724 struct mtk_i2c *i2c = platform_get_drvdata(pdev); 725 726 i2c_del_adapter(&i2c->adap); 727 728 return 0; 729 } 730 731 static struct platform_driver mtk_i2c_driver = { 732 .probe = mtk_i2c_probe, 733 .remove = mtk_i2c_remove, 734 .driver = { 735 .name = I2C_DRV_NAME, 736 .of_match_table = of_match_ptr(mtk_i2c_of_match), 737 }, 738 }; 739 740 module_platform_driver(mtk_i2c_driver); 741 742 MODULE_LICENSE("GPL v2"); 743 MODULE_DESCRIPTION("MediaTek I2C Bus Driver"); 744 MODULE_AUTHOR("Xudong Chen <xudong.chen@mediatek.com>"); 745