1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Copyright (C) 2002 Motorola GSG-China 4 * 5 * Author: 6 * Darius Augulis, Teltonika Inc. 7 * 8 * Desc.: 9 * Implementation of I2C Adapter/Algorithm Driver 10 * for I2C Bus integrated in Freescale i.MX/MXC processors 11 * 12 * Derived from Motorola GSG China I2C example driver 13 * 14 * Copyright (C) 2005 Torsten Koschorrek <koschorrek at synertronixx.de 15 * Copyright (C) 2005 Matthias Blaschke <blaschke at synertronixx.de 16 * Copyright (C) 2007 RightHand Technologies, Inc. 17 * Copyright (C) 2008 Darius Augulis <darius.augulis at teltonika.lt> 18 * 19 * Copyright 2013 Freescale Semiconductor, Inc. 20 * Copyright 2020 NXP 21 * 22 */ 23 24 #include <linux/acpi.h> 25 #include <linux/clk.h> 26 #include <linux/completion.h> 27 #include <linux/delay.h> 28 #include <linux/dma-mapping.h> 29 #include <linux/dmaengine.h> 30 #include <linux/dmapool.h> 31 #include <linux/err.h> 32 #include <linux/errno.h> 33 #include <linux/gpio/consumer.h> 34 #include <linux/i2c.h> 35 #include <linux/init.h> 36 #include <linux/interrupt.h> 37 #include <linux/io.h> 38 #include <linux/iopoll.h> 39 #include <linux/kernel.h> 40 #include <linux/spinlock.h> 41 #include <linux/hrtimer.h> 42 #include <linux/module.h> 43 #include <linux/of.h> 44 #include <linux/of_dma.h> 45 #include <linux/pinctrl/consumer.h> 46 #include <linux/platform_data/i2c-imx.h> 47 #include <linux/platform_device.h> 48 #include <linux/pm_runtime.h> 49 #include <linux/sched.h> 50 #include <linux/slab.h> 51 52 /* This will be the driver name the kernel reports */ 53 #define DRIVER_NAME "imx-i2c" 54 55 #define I2C_IMX_CHECK_DELAY 30000 /* Time to check for bus idle, in NS */ 56 57 /* 58 * Enable DMA if transfer byte size is bigger than this threshold. 59 * As the hardware request, it must bigger than 4 bytes.\ 60 * I have set '16' here, maybe it's not the best but I think it's 61 * the appropriate. 62 */ 63 #define DMA_THRESHOLD 16 64 #define DMA_TIMEOUT 1000 65 66 /* IMX I2C registers: 67 * the I2C register offset is different between SoCs, 68 * to provide support for all these chips, split the 69 * register offset into a fixed base address and a 70 * variable shift value, then the full register offset 71 * will be calculated by 72 * reg_off = ( reg_base_addr << reg_shift) 73 */ 74 #define IMX_I2C_IADR 0x00 /* i2c slave address */ 75 #define IMX_I2C_IFDR 0x01 /* i2c frequency divider */ 76 #define IMX_I2C_I2CR 0x02 /* i2c control */ 77 #define IMX_I2C_I2SR 0x03 /* i2c status */ 78 #define IMX_I2C_I2DR 0x04 /* i2c transfer data */ 79 80 /* 81 * All of the layerscape series SoCs support IBIC register. 82 */ 83 #define IMX_I2C_IBIC 0x05 /* i2c bus interrupt config */ 84 85 #define IMX_I2C_REGSHIFT 2 86 #define VF610_I2C_REGSHIFT 0 87 88 /* Bits of IMX I2C registers */ 89 #define I2SR_RXAK 0x01 90 #define I2SR_IIF 0x02 91 #define I2SR_SRW 0x04 92 #define I2SR_IAL 0x10 93 #define I2SR_IBB 0x20 94 #define I2SR_IAAS 0x40 95 #define I2SR_ICF 0x80 96 #define I2CR_DMAEN 0x02 97 #define I2CR_RSTA 0x04 98 #define I2CR_TXAK 0x08 99 #define I2CR_MTX 0x10 100 #define I2CR_MSTA 0x20 101 #define I2CR_IIEN 0x40 102 #define I2CR_IEN 0x80 103 #define IBIC_BIIE 0x80 /* Bus idle interrupt enable */ 104 105 /* register bits different operating codes definition: 106 * 1) I2SR: Interrupt flags clear operation differ between SoCs: 107 * - write zero to clear(w0c) INT flag on i.MX, 108 * - but write one to clear(w1c) INT flag on Vybrid. 109 * 2) I2CR: I2C module enable operation also differ between SoCs: 110 * - set I2CR_IEN bit enable the module on i.MX, 111 * - but clear I2CR_IEN bit enable the module on Vybrid. 112 */ 113 #define I2SR_CLR_OPCODE_W0C 0x0 114 #define I2SR_CLR_OPCODE_W1C (I2SR_IAL | I2SR_IIF) 115 #define I2CR_IEN_OPCODE_0 0x0 116 #define I2CR_IEN_OPCODE_1 I2CR_IEN 117 118 #define I2C_PM_TIMEOUT 10 /* ms */ 119 120 /* 121 * sorted list of clock divider, register value pairs 122 * taken from table 26-5, p.26-9, Freescale i.MX 123 * Integrated Portable System Processor Reference Manual 124 * Document Number: MC9328MXLRM, Rev. 5.1, 06/2007 125 * 126 * Duplicated divider values removed from list 127 */ 128 struct imx_i2c_clk_pair { 129 u16 div; 130 u16 val; 131 }; 132 133 static struct imx_i2c_clk_pair imx_i2c_clk_div[] = { 134 { 22, 0x20 }, { 24, 0x21 }, { 26, 0x22 }, { 28, 0x23 }, 135 { 30, 0x00 }, { 32, 0x24 }, { 36, 0x25 }, { 40, 0x26 }, 136 { 42, 0x03 }, { 44, 0x27 }, { 48, 0x28 }, { 52, 0x05 }, 137 { 56, 0x29 }, { 60, 0x06 }, { 64, 0x2A }, { 72, 0x2B }, 138 { 80, 0x2C }, { 88, 0x09 }, { 96, 0x2D }, { 104, 0x0A }, 139 { 112, 0x2E }, { 128, 0x2F }, { 144, 0x0C }, { 160, 0x30 }, 140 { 192, 0x31 }, { 224, 0x32 }, { 240, 0x0F }, { 256, 0x33 }, 141 { 288, 0x10 }, { 320, 0x34 }, { 384, 0x35 }, { 448, 0x36 }, 142 { 480, 0x13 }, { 512, 0x37 }, { 576, 0x14 }, { 640, 0x38 }, 143 { 768, 0x39 }, { 896, 0x3A }, { 960, 0x17 }, { 1024, 0x3B }, 144 { 1152, 0x18 }, { 1280, 0x3C }, { 1536, 0x3D }, { 1792, 0x3E }, 145 { 1920, 0x1B }, { 2048, 0x3F }, { 2304, 0x1C }, { 2560, 0x1D }, 146 { 3072, 0x1E }, { 3840, 0x1F } 147 }; 148 149 /* Vybrid VF610 clock divider, register value pairs */ 150 static struct imx_i2c_clk_pair vf610_i2c_clk_div[] = { 151 { 20, 0x00 }, { 22, 0x01 }, { 24, 0x02 }, { 26, 0x03 }, 152 { 28, 0x04 }, { 30, 0x05 }, { 32, 0x09 }, { 34, 0x06 }, 153 { 36, 0x0A }, { 40, 0x07 }, { 44, 0x0C }, { 48, 0x0D }, 154 { 52, 0x43 }, { 56, 0x0E }, { 60, 0x45 }, { 64, 0x12 }, 155 { 68, 0x0F }, { 72, 0x13 }, { 80, 0x14 }, { 88, 0x15 }, 156 { 96, 0x19 }, { 104, 0x16 }, { 112, 0x1A }, { 128, 0x17 }, 157 { 136, 0x4F }, { 144, 0x1C }, { 160, 0x1D }, { 176, 0x55 }, 158 { 192, 0x1E }, { 208, 0x56 }, { 224, 0x22 }, { 228, 0x24 }, 159 { 240, 0x1F }, { 256, 0x23 }, { 288, 0x5C }, { 320, 0x25 }, 160 { 384, 0x26 }, { 448, 0x2A }, { 480, 0x27 }, { 512, 0x2B }, 161 { 576, 0x2C }, { 640, 0x2D }, { 768, 0x31 }, { 896, 0x32 }, 162 { 960, 0x2F }, { 1024, 0x33 }, { 1152, 0x34 }, { 1280, 0x35 }, 163 { 1536, 0x36 }, { 1792, 0x3A }, { 1920, 0x37 }, { 2048, 0x3B }, 164 { 2304, 0x3C }, { 2560, 0x3D }, { 3072, 0x3E }, { 3584, 0x7A }, 165 { 3840, 0x3F }, { 4096, 0x7B }, { 5120, 0x7D }, { 6144, 0x7E }, 166 }; 167 168 enum imx_i2c_type { 169 IMX1_I2C, 170 IMX21_I2C, 171 VF610_I2C, 172 }; 173 174 struct imx_i2c_hwdata { 175 enum imx_i2c_type devtype; 176 unsigned int regshift; 177 struct imx_i2c_clk_pair *clk_div; 178 unsigned int ndivs; 179 unsigned int i2sr_clr_opcode; 180 unsigned int i2cr_ien_opcode; 181 /* 182 * Errata ERR007805 or e7805: 183 * I2C: When the I2C clock speed is configured for 400 kHz, 184 * the SCL low period violates the I2C spec of 1.3 uS min. 185 */ 186 bool has_err007805; 187 }; 188 189 struct imx_i2c_dma { 190 struct dma_chan *chan_tx; 191 struct dma_chan *chan_rx; 192 struct dma_chan *chan_using; 193 struct completion cmd_complete; 194 dma_addr_t dma_buf; 195 unsigned int dma_len; 196 enum dma_transfer_direction dma_transfer_dir; 197 enum dma_data_direction dma_data_dir; 198 }; 199 200 struct imx_i2c_struct { 201 struct i2c_adapter adapter; 202 struct clk *clk; 203 struct notifier_block clk_change_nb; 204 void __iomem *base; 205 wait_queue_head_t queue; 206 unsigned long i2csr; 207 unsigned int disable_delay; 208 int stopped; 209 unsigned int ifdr; /* IMX_I2C_IFDR */ 210 unsigned int cur_clk; 211 unsigned int bitrate; 212 const struct imx_i2c_hwdata *hwdata; 213 struct i2c_bus_recovery_info rinfo; 214 215 struct imx_i2c_dma *dma; 216 struct i2c_client *slave; 217 enum i2c_slave_event last_slave_event; 218 219 /* For checking slave events. */ 220 spinlock_t slave_lock; 221 struct hrtimer slave_timer; 222 }; 223 224 static const struct imx_i2c_hwdata imx1_i2c_hwdata = { 225 .devtype = IMX1_I2C, 226 .regshift = IMX_I2C_REGSHIFT, 227 .clk_div = imx_i2c_clk_div, 228 .ndivs = ARRAY_SIZE(imx_i2c_clk_div), 229 .i2sr_clr_opcode = I2SR_CLR_OPCODE_W0C, 230 .i2cr_ien_opcode = I2CR_IEN_OPCODE_1, 231 232 }; 233 234 static const struct imx_i2c_hwdata imx21_i2c_hwdata = { 235 .devtype = IMX21_I2C, 236 .regshift = IMX_I2C_REGSHIFT, 237 .clk_div = imx_i2c_clk_div, 238 .ndivs = ARRAY_SIZE(imx_i2c_clk_div), 239 .i2sr_clr_opcode = I2SR_CLR_OPCODE_W0C, 240 .i2cr_ien_opcode = I2CR_IEN_OPCODE_1, 241 242 }; 243 244 static const struct imx_i2c_hwdata imx6_i2c_hwdata = { 245 .devtype = IMX21_I2C, 246 .regshift = IMX_I2C_REGSHIFT, 247 .clk_div = imx_i2c_clk_div, 248 .ndivs = ARRAY_SIZE(imx_i2c_clk_div), 249 .i2sr_clr_opcode = I2SR_CLR_OPCODE_W0C, 250 .i2cr_ien_opcode = I2CR_IEN_OPCODE_1, 251 .has_err007805 = true, 252 }; 253 254 static struct imx_i2c_hwdata vf610_i2c_hwdata = { 255 .devtype = VF610_I2C, 256 .regshift = VF610_I2C_REGSHIFT, 257 .clk_div = vf610_i2c_clk_div, 258 .ndivs = ARRAY_SIZE(vf610_i2c_clk_div), 259 .i2sr_clr_opcode = I2SR_CLR_OPCODE_W1C, 260 .i2cr_ien_opcode = I2CR_IEN_OPCODE_0, 261 262 }; 263 264 static const struct platform_device_id imx_i2c_devtype[] = { 265 { 266 .name = "imx1-i2c", 267 .driver_data = (kernel_ulong_t)&imx1_i2c_hwdata, 268 }, { 269 .name = "imx21-i2c", 270 .driver_data = (kernel_ulong_t)&imx21_i2c_hwdata, 271 }, { 272 /* sentinel */ 273 } 274 }; 275 MODULE_DEVICE_TABLE(platform, imx_i2c_devtype); 276 277 static const struct of_device_id i2c_imx_dt_ids[] = { 278 { .compatible = "fsl,imx1-i2c", .data = &imx1_i2c_hwdata, }, 279 { .compatible = "fsl,imx21-i2c", .data = &imx21_i2c_hwdata, }, 280 { .compatible = "fsl,imx6q-i2c", .data = &imx6_i2c_hwdata, }, 281 { .compatible = "fsl,imx6sl-i2c", .data = &imx6_i2c_hwdata, }, 282 { .compatible = "fsl,imx6sll-i2c", .data = &imx6_i2c_hwdata, }, 283 { .compatible = "fsl,imx6sx-i2c", .data = &imx6_i2c_hwdata, }, 284 { .compatible = "fsl,imx6ul-i2c", .data = &imx6_i2c_hwdata, }, 285 { .compatible = "fsl,imx7s-i2c", .data = &imx6_i2c_hwdata, }, 286 { .compatible = "fsl,imx8mm-i2c", .data = &imx6_i2c_hwdata, }, 287 { .compatible = "fsl,imx8mn-i2c", .data = &imx6_i2c_hwdata, }, 288 { .compatible = "fsl,imx8mp-i2c", .data = &imx6_i2c_hwdata, }, 289 { .compatible = "fsl,imx8mq-i2c", .data = &imx6_i2c_hwdata, }, 290 { .compatible = "fsl,vf610-i2c", .data = &vf610_i2c_hwdata, }, 291 { /* sentinel */ } 292 }; 293 MODULE_DEVICE_TABLE(of, i2c_imx_dt_ids); 294 295 static const struct acpi_device_id i2c_imx_acpi_ids[] = { 296 {"NXP0001", .driver_data = (kernel_ulong_t)&vf610_i2c_hwdata}, 297 { } 298 }; 299 MODULE_DEVICE_TABLE(acpi, i2c_imx_acpi_ids); 300 301 static inline int is_imx1_i2c(struct imx_i2c_struct *i2c_imx) 302 { 303 return i2c_imx->hwdata->devtype == IMX1_I2C; 304 } 305 306 static inline int is_vf610_i2c(struct imx_i2c_struct *i2c_imx) 307 { 308 return i2c_imx->hwdata->devtype == VF610_I2C; 309 } 310 311 static inline void imx_i2c_write_reg(unsigned int val, 312 struct imx_i2c_struct *i2c_imx, unsigned int reg) 313 { 314 writeb(val, i2c_imx->base + (reg << i2c_imx->hwdata->regshift)); 315 } 316 317 static inline unsigned char imx_i2c_read_reg(struct imx_i2c_struct *i2c_imx, 318 unsigned int reg) 319 { 320 return readb(i2c_imx->base + (reg << i2c_imx->hwdata->regshift)); 321 } 322 323 static void i2c_imx_clear_irq(struct imx_i2c_struct *i2c_imx, unsigned int bits) 324 { 325 unsigned int temp; 326 327 /* 328 * i2sr_clr_opcode is the value to clear all interrupts. Here we want to 329 * clear only <bits>, so we write ~i2sr_clr_opcode with just <bits> 330 * toggled. This is required because i.MX needs W0C and Vybrid uses W1C. 331 */ 332 temp = ~i2c_imx->hwdata->i2sr_clr_opcode ^ bits; 333 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR); 334 } 335 336 /* Set up i2c controller register and i2c status register to default value. */ 337 static void i2c_imx_reset_regs(struct imx_i2c_struct *i2c_imx) 338 { 339 imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN, 340 i2c_imx, IMX_I2C_I2CR); 341 i2c_imx_clear_irq(i2c_imx, I2SR_IIF | I2SR_IAL); 342 } 343 344 /* Functions for DMA support */ 345 static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx, 346 dma_addr_t phy_addr) 347 { 348 struct imx_i2c_dma *dma; 349 struct dma_slave_config dma_sconfig; 350 struct device *dev = &i2c_imx->adapter.dev; 351 int ret; 352 353 dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL); 354 if (!dma) 355 return; 356 357 dma->chan_tx = dma_request_chan(dev, "tx"); 358 if (IS_ERR(dma->chan_tx)) { 359 ret = PTR_ERR(dma->chan_tx); 360 if (ret != -ENODEV && ret != -EPROBE_DEFER) 361 dev_err(dev, "can't request DMA tx channel (%d)\n", ret); 362 goto fail_al; 363 } 364 365 dma_sconfig.dst_addr = phy_addr + 366 (IMX_I2C_I2DR << i2c_imx->hwdata->regshift); 367 dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; 368 dma_sconfig.dst_maxburst = 1; 369 dma_sconfig.direction = DMA_MEM_TO_DEV; 370 ret = dmaengine_slave_config(dma->chan_tx, &dma_sconfig); 371 if (ret < 0) { 372 dev_err(dev, "can't configure tx channel (%d)\n", ret); 373 goto fail_tx; 374 } 375 376 dma->chan_rx = dma_request_chan(dev, "rx"); 377 if (IS_ERR(dma->chan_rx)) { 378 ret = PTR_ERR(dma->chan_rx); 379 if (ret != -ENODEV && ret != -EPROBE_DEFER) 380 dev_err(dev, "can't request DMA rx channel (%d)\n", ret); 381 goto fail_tx; 382 } 383 384 dma_sconfig.src_addr = phy_addr + 385 (IMX_I2C_I2DR << i2c_imx->hwdata->regshift); 386 dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; 387 dma_sconfig.src_maxburst = 1; 388 dma_sconfig.direction = DMA_DEV_TO_MEM; 389 ret = dmaengine_slave_config(dma->chan_rx, &dma_sconfig); 390 if (ret < 0) { 391 dev_err(dev, "can't configure rx channel (%d)\n", ret); 392 goto fail_rx; 393 } 394 395 i2c_imx->dma = dma; 396 init_completion(&dma->cmd_complete); 397 dev_info(dev, "using %s (tx) and %s (rx) for DMA transfers\n", 398 dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx)); 399 400 return; 401 402 fail_rx: 403 dma_release_channel(dma->chan_rx); 404 fail_tx: 405 dma_release_channel(dma->chan_tx); 406 fail_al: 407 devm_kfree(dev, dma); 408 } 409 410 static void i2c_imx_dma_callback(void *arg) 411 { 412 struct imx_i2c_struct *i2c_imx = (struct imx_i2c_struct *)arg; 413 struct imx_i2c_dma *dma = i2c_imx->dma; 414 415 dma_unmap_single(dma->chan_using->device->dev, dma->dma_buf, 416 dma->dma_len, dma->dma_data_dir); 417 complete(&dma->cmd_complete); 418 } 419 420 static int i2c_imx_dma_xfer(struct imx_i2c_struct *i2c_imx, 421 struct i2c_msg *msgs) 422 { 423 struct imx_i2c_dma *dma = i2c_imx->dma; 424 struct dma_async_tx_descriptor *txdesc; 425 struct device *dev = &i2c_imx->adapter.dev; 426 struct device *chan_dev = dma->chan_using->device->dev; 427 428 dma->dma_buf = dma_map_single(chan_dev, msgs->buf, 429 dma->dma_len, dma->dma_data_dir); 430 if (dma_mapping_error(chan_dev, dma->dma_buf)) { 431 dev_err(dev, "DMA mapping failed\n"); 432 goto err_map; 433 } 434 435 txdesc = dmaengine_prep_slave_single(dma->chan_using, dma->dma_buf, 436 dma->dma_len, dma->dma_transfer_dir, 437 DMA_PREP_INTERRUPT | DMA_CTRL_ACK); 438 if (!txdesc) { 439 dev_err(dev, "Not able to get desc for DMA xfer\n"); 440 goto err_desc; 441 } 442 443 reinit_completion(&dma->cmd_complete); 444 txdesc->callback = i2c_imx_dma_callback; 445 txdesc->callback_param = i2c_imx; 446 if (dma_submit_error(dmaengine_submit(txdesc))) { 447 dev_err(dev, "DMA submit failed\n"); 448 goto err_submit; 449 } 450 451 dma_async_issue_pending(dma->chan_using); 452 return 0; 453 454 err_submit: 455 dmaengine_terminate_sync(dma->chan_using); 456 err_desc: 457 dma_unmap_single(chan_dev, dma->dma_buf, 458 dma->dma_len, dma->dma_data_dir); 459 err_map: 460 return -EINVAL; 461 } 462 463 static void i2c_imx_dma_free(struct imx_i2c_struct *i2c_imx) 464 { 465 struct imx_i2c_dma *dma = i2c_imx->dma; 466 467 dma->dma_buf = 0; 468 dma->dma_len = 0; 469 470 dma_release_channel(dma->chan_tx); 471 dma->chan_tx = NULL; 472 473 dma_release_channel(dma->chan_rx); 474 dma->chan_rx = NULL; 475 476 dma->chan_using = NULL; 477 } 478 479 static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool atomic) 480 { 481 unsigned long orig_jiffies = jiffies; 482 unsigned int temp; 483 484 while (1) { 485 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); 486 487 /* check for arbitration lost */ 488 if (temp & I2SR_IAL) { 489 i2c_imx_clear_irq(i2c_imx, I2SR_IAL); 490 return -EAGAIN; 491 } 492 493 if (for_busy && (temp & I2SR_IBB)) { 494 i2c_imx->stopped = 0; 495 break; 496 } 497 if (!for_busy && !(temp & I2SR_IBB)) { 498 i2c_imx->stopped = 1; 499 break; 500 } 501 if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) { 502 dev_dbg(&i2c_imx->adapter.dev, 503 "<%s> I2C bus is busy\n", __func__); 504 return -ETIMEDOUT; 505 } 506 if (atomic) 507 udelay(100); 508 else 509 schedule(); 510 } 511 512 return 0; 513 } 514 515 static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx, bool atomic) 516 { 517 if (atomic) { 518 void __iomem *addr = i2c_imx->base + (IMX_I2C_I2SR << i2c_imx->hwdata->regshift); 519 unsigned int regval; 520 521 /* 522 * The formula for the poll timeout is documented in the RM 523 * Rev.5 on page 1878: 524 * T_min = 10/F_scl 525 * Set the value hard as it is done for the non-atomic use-case. 526 * Use 10 kHz for the calculation since this is the minimum 527 * allowed SMBus frequency. Also add an offset of 100us since it 528 * turned out that the I2SR_IIF bit isn't set correctly within 529 * the minimum timeout in polling mode. 530 */ 531 readb_poll_timeout_atomic(addr, regval, regval & I2SR_IIF, 5, 1000 + 100); 532 i2c_imx->i2csr = regval; 533 i2c_imx_clear_irq(i2c_imx, I2SR_IIF | I2SR_IAL); 534 } else { 535 wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10); 536 } 537 538 if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) { 539 dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__); 540 return -ETIMEDOUT; 541 } 542 543 /* check for arbitration lost */ 544 if (i2c_imx->i2csr & I2SR_IAL) { 545 dev_dbg(&i2c_imx->adapter.dev, "<%s> Arbitration lost\n", __func__); 546 i2c_imx_clear_irq(i2c_imx, I2SR_IAL); 547 548 i2c_imx->i2csr = 0; 549 return -EAGAIN; 550 } 551 552 dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__); 553 i2c_imx->i2csr = 0; 554 return 0; 555 } 556 557 static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx) 558 { 559 if (imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR) & I2SR_RXAK) { 560 dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__); 561 return -ENXIO; /* No ACK */ 562 } 563 564 dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__); 565 return 0; 566 } 567 568 static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx, 569 unsigned int i2c_clk_rate) 570 { 571 struct imx_i2c_clk_pair *i2c_clk_div = i2c_imx->hwdata->clk_div; 572 unsigned int div; 573 int i; 574 575 if (i2c_imx->hwdata->has_err007805 && i2c_imx->bitrate > 384000) { 576 dev_dbg(&i2c_imx->adapter.dev, 577 "SoC errata ERR007805 or e7805 applies, bus frequency limited from %d Hz to 384000 Hz.\n", 578 i2c_imx->bitrate); 579 i2c_imx->bitrate = 384000; 580 } 581 582 /* Divider value calculation */ 583 if (i2c_imx->cur_clk == i2c_clk_rate) 584 return; 585 586 i2c_imx->cur_clk = i2c_clk_rate; 587 588 div = DIV_ROUND_UP(i2c_clk_rate, i2c_imx->bitrate); 589 if (div < i2c_clk_div[0].div) 590 i = 0; 591 else if (div > i2c_clk_div[i2c_imx->hwdata->ndivs - 1].div) 592 i = i2c_imx->hwdata->ndivs - 1; 593 else 594 for (i = 0; i2c_clk_div[i].div < div; i++) 595 ; 596 597 /* Store divider value */ 598 i2c_imx->ifdr = i2c_clk_div[i].val; 599 600 /* 601 * There dummy delay is calculated. 602 * It should be about one I2C clock period long. 603 * This delay is used in I2C bus disable function 604 * to fix chip hardware bug. 605 */ 606 i2c_imx->disable_delay = DIV_ROUND_UP(500000U * i2c_clk_div[i].div, 607 i2c_clk_rate / 2); 608 609 #ifdef CONFIG_I2C_DEBUG_BUS 610 dev_dbg(&i2c_imx->adapter.dev, "I2C_CLK=%d, REQ DIV=%d\n", 611 i2c_clk_rate, div); 612 dev_dbg(&i2c_imx->adapter.dev, "IFDR[IC]=0x%x, REAL DIV=%d\n", 613 i2c_clk_div[i].val, i2c_clk_div[i].div); 614 #endif 615 } 616 617 static int i2c_imx_clk_notifier_call(struct notifier_block *nb, 618 unsigned long action, void *data) 619 { 620 struct clk_notifier_data *ndata = data; 621 struct imx_i2c_struct *i2c_imx = container_of(nb, 622 struct imx_i2c_struct, 623 clk_change_nb); 624 625 if (action & POST_RATE_CHANGE) 626 i2c_imx_set_clk(i2c_imx, ndata->new_rate); 627 628 return NOTIFY_OK; 629 } 630 631 static int i2c_imx_start(struct imx_i2c_struct *i2c_imx, bool atomic) 632 { 633 unsigned int temp = 0; 634 int result; 635 636 imx_i2c_write_reg(i2c_imx->ifdr, i2c_imx, IMX_I2C_IFDR); 637 /* Enable I2C controller */ 638 imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR); 639 imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode, i2c_imx, IMX_I2C_I2CR); 640 641 /* Wait controller to be stable */ 642 if (atomic) 643 udelay(50); 644 else 645 usleep_range(50, 150); 646 647 /* Start I2C transaction */ 648 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 649 temp |= I2CR_MSTA; 650 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 651 result = i2c_imx_bus_busy(i2c_imx, 1, atomic); 652 if (result) 653 return result; 654 655 temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK; 656 if (atomic) 657 temp &= ~I2CR_IIEN; /* Disable interrupt */ 658 659 temp &= ~I2CR_DMAEN; 660 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 661 return result; 662 } 663 664 static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx, bool atomic) 665 { 666 unsigned int temp = 0; 667 668 if (!i2c_imx->stopped) { 669 /* Stop I2C transaction */ 670 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 671 if (!(temp & I2CR_MSTA)) 672 i2c_imx->stopped = 1; 673 temp &= ~(I2CR_MSTA | I2CR_MTX); 674 if (i2c_imx->dma) 675 temp &= ~I2CR_DMAEN; 676 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 677 } 678 if (is_imx1_i2c(i2c_imx)) { 679 /* 680 * This delay caused by an i.MXL hardware bug. 681 * If no (or too short) delay, no "STOP" bit will be generated. 682 */ 683 udelay(i2c_imx->disable_delay); 684 } 685 686 if (!i2c_imx->stopped) 687 i2c_imx_bus_busy(i2c_imx, 0, atomic); 688 689 /* Disable I2C controller */ 690 temp = i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN, 691 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 692 } 693 694 /* 695 * Enable bus idle interrupts 696 * Note: IBIC register will be cleared after disabled i2c module. 697 * All of layerscape series SoCs support IBIC register. 698 */ 699 static void i2c_imx_enable_bus_idle(struct imx_i2c_struct *i2c_imx) 700 { 701 if (is_vf610_i2c(i2c_imx)) { 702 unsigned int temp; 703 704 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_IBIC); 705 temp |= IBIC_BIIE; 706 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_IBIC); 707 } 708 } 709 710 static void i2c_imx_slave_event(struct imx_i2c_struct *i2c_imx, 711 enum i2c_slave_event event, u8 *val) 712 { 713 i2c_slave_event(i2c_imx->slave, event, val); 714 i2c_imx->last_slave_event = event; 715 } 716 717 static void i2c_imx_slave_finish_op(struct imx_i2c_struct *i2c_imx) 718 { 719 u8 val = 0; 720 721 while (i2c_imx->last_slave_event != I2C_SLAVE_STOP) { 722 switch (i2c_imx->last_slave_event) { 723 case I2C_SLAVE_READ_REQUESTED: 724 i2c_imx_slave_event(i2c_imx, I2C_SLAVE_READ_PROCESSED, 725 &val); 726 break; 727 728 case I2C_SLAVE_WRITE_REQUESTED: 729 case I2C_SLAVE_READ_PROCESSED: 730 case I2C_SLAVE_WRITE_RECEIVED: 731 i2c_imx_slave_event(i2c_imx, I2C_SLAVE_STOP, &val); 732 break; 733 734 case I2C_SLAVE_STOP: 735 break; 736 } 737 } 738 } 739 740 /* Returns true if the timer should be restarted, false if not. */ 741 static irqreturn_t i2c_imx_slave_handle(struct imx_i2c_struct *i2c_imx, 742 unsigned int status, unsigned int ctl) 743 { 744 u8 value = 0; 745 746 if (status & I2SR_IAL) { /* Arbitration lost */ 747 i2c_imx_clear_irq(i2c_imx, I2SR_IAL); 748 if (!(status & I2SR_IAAS)) 749 return IRQ_HANDLED; 750 } 751 752 if (!(status & I2SR_IBB)) { 753 /* No master on the bus, that could mean a stop condition. */ 754 i2c_imx_slave_finish_op(i2c_imx); 755 return IRQ_HANDLED; 756 } 757 758 if (!(status & I2SR_ICF)) 759 /* Data transfer still in progress, ignore this. */ 760 goto out; 761 762 if (status & I2SR_IAAS) { /* Addressed as a slave */ 763 i2c_imx_slave_finish_op(i2c_imx); 764 if (status & I2SR_SRW) { /* Master wants to read from us*/ 765 dev_dbg(&i2c_imx->adapter.dev, "read requested"); 766 i2c_imx_slave_event(i2c_imx, 767 I2C_SLAVE_READ_REQUESTED, &value); 768 769 /* Slave transmit */ 770 ctl |= I2CR_MTX; 771 imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); 772 773 /* Send data */ 774 imx_i2c_write_reg(value, i2c_imx, IMX_I2C_I2DR); 775 } else { /* Master wants to write to us */ 776 dev_dbg(&i2c_imx->adapter.dev, "write requested"); 777 i2c_imx_slave_event(i2c_imx, 778 I2C_SLAVE_WRITE_REQUESTED, &value); 779 780 /* Slave receive */ 781 ctl &= ~I2CR_MTX; 782 imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); 783 /* Dummy read */ 784 imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); 785 } 786 } else if (!(ctl & I2CR_MTX)) { /* Receive mode */ 787 value = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); 788 i2c_imx_slave_event(i2c_imx, 789 I2C_SLAVE_WRITE_RECEIVED, &value); 790 } else if (!(status & I2SR_RXAK)) { /* Transmit mode received ACK */ 791 ctl |= I2CR_MTX; 792 imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); 793 794 i2c_imx_slave_event(i2c_imx, 795 I2C_SLAVE_READ_PROCESSED, &value); 796 797 imx_i2c_write_reg(value, i2c_imx, IMX_I2C_I2DR); 798 } else { /* Transmit mode received NAK, operation is done */ 799 ctl &= ~I2CR_MTX; 800 imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); 801 imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); 802 803 /* flag the last byte as processed */ 804 i2c_imx_slave_event(i2c_imx, 805 I2C_SLAVE_READ_PROCESSED, &value); 806 807 i2c_imx_slave_finish_op(i2c_imx); 808 return IRQ_HANDLED; 809 } 810 811 out: 812 /* 813 * No need to check the return value here. If it returns 0 or 814 * 1, then everything is fine. If it returns -1, then the 815 * timer is running in the handler. This will still work, 816 * though it may be redone (or already have been done) by the 817 * timer function. 818 */ 819 hrtimer_try_to_cancel(&i2c_imx->slave_timer); 820 hrtimer_forward_now(&i2c_imx->slave_timer, I2C_IMX_CHECK_DELAY); 821 hrtimer_restart(&i2c_imx->slave_timer); 822 return IRQ_HANDLED; 823 } 824 825 static enum hrtimer_restart i2c_imx_slave_timeout(struct hrtimer *t) 826 { 827 struct imx_i2c_struct *i2c_imx = container_of(t, struct imx_i2c_struct, 828 slave_timer); 829 unsigned int ctl, status; 830 unsigned long flags; 831 832 spin_lock_irqsave(&i2c_imx->slave_lock, flags); 833 status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); 834 ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 835 i2c_imx_slave_handle(i2c_imx, status, ctl); 836 spin_unlock_irqrestore(&i2c_imx->slave_lock, flags); 837 return HRTIMER_NORESTART; 838 } 839 840 static void i2c_imx_slave_init(struct imx_i2c_struct *i2c_imx) 841 { 842 int temp; 843 844 /* Set slave addr. */ 845 imx_i2c_write_reg((i2c_imx->slave->addr << 1), i2c_imx, IMX_I2C_IADR); 846 847 i2c_imx_reset_regs(i2c_imx); 848 849 /* Enable module */ 850 temp = i2c_imx->hwdata->i2cr_ien_opcode; 851 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 852 853 /* Enable interrupt from i2c module */ 854 temp |= I2CR_IIEN; 855 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 856 857 i2c_imx_enable_bus_idle(i2c_imx); 858 } 859 860 static int i2c_imx_reg_slave(struct i2c_client *client) 861 { 862 struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(client->adapter); 863 int ret; 864 865 if (i2c_imx->slave) 866 return -EBUSY; 867 868 i2c_imx->slave = client; 869 i2c_imx->last_slave_event = I2C_SLAVE_STOP; 870 871 /* Resume */ 872 ret = pm_runtime_resume_and_get(i2c_imx->adapter.dev.parent); 873 if (ret < 0) { 874 dev_err(&i2c_imx->adapter.dev, "failed to resume i2c controller"); 875 return ret; 876 } 877 878 i2c_imx_slave_init(i2c_imx); 879 880 return 0; 881 } 882 883 static int i2c_imx_unreg_slave(struct i2c_client *client) 884 { 885 struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(client->adapter); 886 int ret; 887 888 if (!i2c_imx->slave) 889 return -EINVAL; 890 891 /* Reset slave address. */ 892 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IADR); 893 894 i2c_imx_reset_regs(i2c_imx); 895 896 i2c_imx->slave = NULL; 897 898 /* Suspend */ 899 ret = pm_runtime_put_sync(i2c_imx->adapter.dev.parent); 900 if (ret < 0) 901 dev_err(&i2c_imx->adapter.dev, "failed to suspend i2c controller"); 902 903 return ret; 904 } 905 906 static irqreturn_t i2c_imx_master_isr(struct imx_i2c_struct *i2c_imx, unsigned int status) 907 { 908 /* save status register */ 909 i2c_imx->i2csr = status; 910 wake_up(&i2c_imx->queue); 911 912 return IRQ_HANDLED; 913 } 914 915 static irqreturn_t i2c_imx_isr(int irq, void *dev_id) 916 { 917 struct imx_i2c_struct *i2c_imx = dev_id; 918 unsigned int ctl, status; 919 unsigned long flags; 920 921 spin_lock_irqsave(&i2c_imx->slave_lock, flags); 922 status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); 923 ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 924 925 if (status & I2SR_IIF) { 926 i2c_imx_clear_irq(i2c_imx, I2SR_IIF); 927 if (i2c_imx->slave) { 928 if (!(ctl & I2CR_MSTA)) { 929 irqreturn_t ret; 930 931 ret = i2c_imx_slave_handle(i2c_imx, 932 status, ctl); 933 spin_unlock_irqrestore(&i2c_imx->slave_lock, 934 flags); 935 return ret; 936 } 937 i2c_imx_slave_finish_op(i2c_imx); 938 } 939 spin_unlock_irqrestore(&i2c_imx->slave_lock, flags); 940 return i2c_imx_master_isr(i2c_imx, status); 941 } 942 spin_unlock_irqrestore(&i2c_imx->slave_lock, flags); 943 944 return IRQ_NONE; 945 } 946 947 static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx, 948 struct i2c_msg *msgs) 949 { 950 int result; 951 unsigned long time_left; 952 unsigned int temp = 0; 953 unsigned long orig_jiffies = jiffies; 954 struct imx_i2c_dma *dma = i2c_imx->dma; 955 struct device *dev = &i2c_imx->adapter.dev; 956 957 dma->chan_using = dma->chan_tx; 958 dma->dma_transfer_dir = DMA_MEM_TO_DEV; 959 dma->dma_data_dir = DMA_TO_DEVICE; 960 dma->dma_len = msgs->len - 1; 961 result = i2c_imx_dma_xfer(i2c_imx, msgs); 962 if (result) 963 return result; 964 965 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 966 temp |= I2CR_DMAEN; 967 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 968 969 /* 970 * Write slave address. 971 * The first byte must be transmitted by the CPU. 972 */ 973 imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR); 974 time_left = wait_for_completion_timeout( 975 &i2c_imx->dma->cmd_complete, 976 msecs_to_jiffies(DMA_TIMEOUT)); 977 if (time_left == 0) { 978 dmaengine_terminate_sync(dma->chan_using); 979 return -ETIMEDOUT; 980 } 981 982 /* Waiting for transfer complete. */ 983 while (1) { 984 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); 985 if (temp & I2SR_ICF) 986 break; 987 if (time_after(jiffies, orig_jiffies + 988 msecs_to_jiffies(DMA_TIMEOUT))) { 989 dev_dbg(dev, "<%s> Timeout\n", __func__); 990 return -ETIMEDOUT; 991 } 992 schedule(); 993 } 994 995 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 996 temp &= ~I2CR_DMAEN; 997 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 998 999 /* The last data byte must be transferred by the CPU. */ 1000 imx_i2c_write_reg(msgs->buf[msgs->len-1], 1001 i2c_imx, IMX_I2C_I2DR); 1002 result = i2c_imx_trx_complete(i2c_imx, false); 1003 if (result) 1004 return result; 1005 1006 return i2c_imx_acked(i2c_imx); 1007 } 1008 1009 static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx, 1010 struct i2c_msg *msgs, bool is_lastmsg) 1011 { 1012 int result; 1013 unsigned long time_left; 1014 unsigned int temp; 1015 unsigned long orig_jiffies = jiffies; 1016 struct imx_i2c_dma *dma = i2c_imx->dma; 1017 struct device *dev = &i2c_imx->adapter.dev; 1018 1019 1020 dma->chan_using = dma->chan_rx; 1021 dma->dma_transfer_dir = DMA_DEV_TO_MEM; 1022 dma->dma_data_dir = DMA_FROM_DEVICE; 1023 /* The last two data bytes must be transferred by the CPU. */ 1024 dma->dma_len = msgs->len - 2; 1025 result = i2c_imx_dma_xfer(i2c_imx, msgs); 1026 if (result) 1027 return result; 1028 1029 time_left = wait_for_completion_timeout( 1030 &i2c_imx->dma->cmd_complete, 1031 msecs_to_jiffies(DMA_TIMEOUT)); 1032 if (time_left == 0) { 1033 dmaengine_terminate_sync(dma->chan_using); 1034 return -ETIMEDOUT; 1035 } 1036 1037 /* waiting for transfer complete. */ 1038 while (1) { 1039 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); 1040 if (temp & I2SR_ICF) 1041 break; 1042 if (time_after(jiffies, orig_jiffies + 1043 msecs_to_jiffies(DMA_TIMEOUT))) { 1044 dev_dbg(dev, "<%s> Timeout\n", __func__); 1045 return -ETIMEDOUT; 1046 } 1047 schedule(); 1048 } 1049 1050 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1051 temp &= ~I2CR_DMAEN; 1052 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 1053 1054 /* read n-1 byte data */ 1055 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1056 temp |= I2CR_TXAK; 1057 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 1058 1059 msgs->buf[msgs->len-2] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); 1060 /* read n byte data */ 1061 result = i2c_imx_trx_complete(i2c_imx, false); 1062 if (result) 1063 return result; 1064 1065 if (is_lastmsg) { 1066 /* 1067 * It must generate STOP before read I2DR to prevent 1068 * controller from generating another clock cycle 1069 */ 1070 dev_dbg(dev, "<%s> clear MSTA\n", __func__); 1071 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1072 if (!(temp & I2CR_MSTA)) 1073 i2c_imx->stopped = 1; 1074 temp &= ~(I2CR_MSTA | I2CR_MTX); 1075 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 1076 if (!i2c_imx->stopped) 1077 i2c_imx_bus_busy(i2c_imx, 0, false); 1078 } else { 1079 /* 1080 * For i2c master receiver repeat restart operation like: 1081 * read -> repeat MSTA -> read/write 1082 * The controller must set MTX before read the last byte in 1083 * the first read operation, otherwise the first read cost 1084 * one extra clock cycle. 1085 */ 1086 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1087 temp |= I2CR_MTX; 1088 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 1089 } 1090 msgs->buf[msgs->len-1] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); 1091 1092 return 0; 1093 } 1094 1095 static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, 1096 bool atomic) 1097 { 1098 int i, result; 1099 1100 dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n", 1101 __func__, i2c_8bit_addr_from_msg(msgs)); 1102 1103 /* write slave address */ 1104 imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR); 1105 result = i2c_imx_trx_complete(i2c_imx, atomic); 1106 if (result) 1107 return result; 1108 result = i2c_imx_acked(i2c_imx); 1109 if (result) 1110 return result; 1111 dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__); 1112 1113 /* write data */ 1114 for (i = 0; i < msgs->len; i++) { 1115 dev_dbg(&i2c_imx->adapter.dev, 1116 "<%s> write byte: B%d=0x%X\n", 1117 __func__, i, msgs->buf[i]); 1118 imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR); 1119 result = i2c_imx_trx_complete(i2c_imx, atomic); 1120 if (result) 1121 return result; 1122 result = i2c_imx_acked(i2c_imx); 1123 if (result) 1124 return result; 1125 } 1126 return 0; 1127 } 1128 1129 static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, 1130 bool is_lastmsg, bool atomic) 1131 { 1132 int i, result; 1133 unsigned int temp; 1134 int block_data = msgs->flags & I2C_M_RECV_LEN; 1135 int use_dma = i2c_imx->dma && msgs->flags & I2C_M_DMA_SAFE && 1136 msgs->len >= DMA_THRESHOLD && !block_data; 1137 1138 dev_dbg(&i2c_imx->adapter.dev, 1139 "<%s> write slave address: addr=0x%x\n", 1140 __func__, i2c_8bit_addr_from_msg(msgs)); 1141 1142 /* write slave address */ 1143 imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR); 1144 result = i2c_imx_trx_complete(i2c_imx, atomic); 1145 if (result) 1146 return result; 1147 result = i2c_imx_acked(i2c_imx); 1148 if (result) 1149 return result; 1150 1151 dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__); 1152 1153 /* setup bus to read data */ 1154 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1155 temp &= ~I2CR_MTX; 1156 1157 /* 1158 * Reset the I2CR_TXAK flag initially for SMBus block read since the 1159 * length is unknown 1160 */ 1161 if ((msgs->len - 1) || block_data) 1162 temp &= ~I2CR_TXAK; 1163 if (use_dma) 1164 temp |= I2CR_DMAEN; 1165 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 1166 imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); /* dummy read */ 1167 1168 dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__); 1169 1170 if (use_dma) 1171 return i2c_imx_dma_read(i2c_imx, msgs, is_lastmsg); 1172 1173 /* read data */ 1174 for (i = 0; i < msgs->len; i++) { 1175 u8 len = 0; 1176 1177 result = i2c_imx_trx_complete(i2c_imx, atomic); 1178 if (result) 1179 return result; 1180 /* 1181 * First byte is the length of remaining packet 1182 * in the SMBus block data read. Add it to 1183 * msgs->len. 1184 */ 1185 if ((!i) && block_data) { 1186 len = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); 1187 if ((len == 0) || (len > I2C_SMBUS_BLOCK_MAX)) 1188 return -EPROTO; 1189 dev_dbg(&i2c_imx->adapter.dev, 1190 "<%s> read length: 0x%X\n", 1191 __func__, len); 1192 msgs->len += len; 1193 } 1194 if (i == (msgs->len - 1)) { 1195 if (is_lastmsg) { 1196 /* 1197 * It must generate STOP before read I2DR to prevent 1198 * controller from generating another clock cycle 1199 */ 1200 dev_dbg(&i2c_imx->adapter.dev, 1201 "<%s> clear MSTA\n", __func__); 1202 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1203 if (!(temp & I2CR_MSTA)) 1204 i2c_imx->stopped = 1; 1205 temp &= ~(I2CR_MSTA | I2CR_MTX); 1206 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 1207 if (!i2c_imx->stopped) 1208 i2c_imx_bus_busy(i2c_imx, 0, atomic); 1209 } else { 1210 /* 1211 * For i2c master receiver repeat restart operation like: 1212 * read -> repeat MSTA -> read/write 1213 * The controller must set MTX before read the last byte in 1214 * the first read operation, otherwise the first read cost 1215 * one extra clock cycle. 1216 */ 1217 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1218 temp |= I2CR_MTX; 1219 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 1220 } 1221 } else if (i == (msgs->len - 2)) { 1222 dev_dbg(&i2c_imx->adapter.dev, 1223 "<%s> set TXAK\n", __func__); 1224 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1225 temp |= I2CR_TXAK; 1226 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 1227 } 1228 if ((!i) && block_data) 1229 msgs->buf[0] = len; 1230 else 1231 msgs->buf[i] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); 1232 dev_dbg(&i2c_imx->adapter.dev, 1233 "<%s> read byte: B%d=0x%X\n", 1234 __func__, i, msgs->buf[i]); 1235 } 1236 return 0; 1237 } 1238 1239 static int i2c_imx_xfer_common(struct i2c_adapter *adapter, 1240 struct i2c_msg *msgs, int num, bool atomic) 1241 { 1242 unsigned int i, temp; 1243 int result; 1244 bool is_lastmsg = false; 1245 struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter); 1246 1247 /* Start I2C transfer */ 1248 result = i2c_imx_start(i2c_imx, atomic); 1249 if (result) { 1250 /* 1251 * Bus recovery uses gpiod_get_value_cansleep() which is not 1252 * allowed within atomic context. 1253 */ 1254 if (!atomic && i2c_imx->adapter.bus_recovery_info) { 1255 i2c_recover_bus(&i2c_imx->adapter); 1256 result = i2c_imx_start(i2c_imx, atomic); 1257 } 1258 } 1259 1260 if (result) 1261 goto fail0; 1262 1263 /* read/write data */ 1264 for (i = 0; i < num; i++) { 1265 if (i == num - 1) 1266 is_lastmsg = true; 1267 1268 if (i) { 1269 dev_dbg(&i2c_imx->adapter.dev, 1270 "<%s> repeated start\n", __func__); 1271 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1272 temp |= I2CR_RSTA; 1273 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 1274 result = i2c_imx_bus_busy(i2c_imx, 1, atomic); 1275 if (result) 1276 goto fail0; 1277 } 1278 dev_dbg(&i2c_imx->adapter.dev, 1279 "<%s> transfer message: %d\n", __func__, i); 1280 /* write/read data */ 1281 #ifdef CONFIG_I2C_DEBUG_BUS 1282 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1283 dev_dbg(&i2c_imx->adapter.dev, 1284 "<%s> CONTROL: IEN=%d, IIEN=%d, MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n", 1285 __func__, 1286 (temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0), 1287 (temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0), 1288 (temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0)); 1289 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); 1290 dev_dbg(&i2c_imx->adapter.dev, 1291 "<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n", 1292 __func__, 1293 (temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0), 1294 (temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0), 1295 (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0), 1296 (temp & I2SR_RXAK ? 1 : 0)); 1297 #endif 1298 if (msgs[i].flags & I2C_M_RD) { 1299 result = i2c_imx_read(i2c_imx, &msgs[i], is_lastmsg, atomic); 1300 } else { 1301 if (!atomic && 1302 i2c_imx->dma && msgs[i].len >= DMA_THRESHOLD && 1303 msgs[i].flags & I2C_M_DMA_SAFE) 1304 result = i2c_imx_dma_write(i2c_imx, &msgs[i]); 1305 else 1306 result = i2c_imx_write(i2c_imx, &msgs[i], atomic); 1307 } 1308 if (result) 1309 goto fail0; 1310 } 1311 1312 fail0: 1313 /* Stop I2C transfer */ 1314 i2c_imx_stop(i2c_imx, atomic); 1315 1316 dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__, 1317 (result < 0) ? "error" : "success msg", 1318 (result < 0) ? result : num); 1319 /* After data is transferred, switch to slave mode(as a receiver) */ 1320 if (i2c_imx->slave) 1321 i2c_imx_slave_init(i2c_imx); 1322 1323 return (result < 0) ? result : num; 1324 } 1325 1326 static int i2c_imx_xfer(struct i2c_adapter *adapter, 1327 struct i2c_msg *msgs, int num) 1328 { 1329 struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter); 1330 int result; 1331 1332 result = pm_runtime_resume_and_get(i2c_imx->adapter.dev.parent); 1333 if (result < 0) 1334 return result; 1335 1336 result = i2c_imx_xfer_common(adapter, msgs, num, false); 1337 1338 pm_runtime_mark_last_busy(i2c_imx->adapter.dev.parent); 1339 pm_runtime_put_autosuspend(i2c_imx->adapter.dev.parent); 1340 1341 return result; 1342 } 1343 1344 static int i2c_imx_xfer_atomic(struct i2c_adapter *adapter, 1345 struct i2c_msg *msgs, int num) 1346 { 1347 struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter); 1348 int result; 1349 1350 result = clk_enable(i2c_imx->clk); 1351 if (result) 1352 return result; 1353 1354 result = i2c_imx_xfer_common(adapter, msgs, num, true); 1355 1356 clk_disable(i2c_imx->clk); 1357 1358 return result; 1359 } 1360 1361 /* 1362 * We switch SCL and SDA to their GPIO function and do some bitbanging 1363 * for bus recovery. These alternative pinmux settings can be 1364 * described in the device tree by a separate pinctrl state "gpio". If 1365 * this is missing this is not a big problem, the only implication is 1366 * that we can't do bus recovery. 1367 */ 1368 static int i2c_imx_init_recovery_info(struct imx_i2c_struct *i2c_imx, 1369 struct platform_device *pdev) 1370 { 1371 struct i2c_bus_recovery_info *bri = &i2c_imx->rinfo; 1372 1373 bri->pinctrl = devm_pinctrl_get(&pdev->dev); 1374 if (IS_ERR(bri->pinctrl)) 1375 return PTR_ERR(bri->pinctrl); 1376 1377 i2c_imx->adapter.bus_recovery_info = bri; 1378 1379 return 0; 1380 } 1381 1382 static u32 i2c_imx_func(struct i2c_adapter *adapter) 1383 { 1384 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL 1385 | I2C_FUNC_SMBUS_READ_BLOCK_DATA; 1386 } 1387 1388 static const struct i2c_algorithm i2c_imx_algo = { 1389 .master_xfer = i2c_imx_xfer, 1390 .master_xfer_atomic = i2c_imx_xfer_atomic, 1391 .functionality = i2c_imx_func, 1392 .reg_slave = i2c_imx_reg_slave, 1393 .unreg_slave = i2c_imx_unreg_slave, 1394 }; 1395 1396 static int i2c_imx_probe(struct platform_device *pdev) 1397 { 1398 struct imx_i2c_struct *i2c_imx; 1399 struct resource *res; 1400 struct imxi2c_platform_data *pdata = dev_get_platdata(&pdev->dev); 1401 void __iomem *base; 1402 int irq, ret; 1403 dma_addr_t phy_addr; 1404 const struct imx_i2c_hwdata *match; 1405 1406 irq = platform_get_irq(pdev, 0); 1407 if (irq < 0) 1408 return irq; 1409 1410 base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); 1411 if (IS_ERR(base)) 1412 return PTR_ERR(base); 1413 1414 phy_addr = (dma_addr_t)res->start; 1415 i2c_imx = devm_kzalloc(&pdev->dev, sizeof(*i2c_imx), GFP_KERNEL); 1416 if (!i2c_imx) 1417 return -ENOMEM; 1418 1419 spin_lock_init(&i2c_imx->slave_lock); 1420 hrtimer_init(&i2c_imx->slave_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); 1421 i2c_imx->slave_timer.function = i2c_imx_slave_timeout; 1422 1423 match = device_get_match_data(&pdev->dev); 1424 if (match) 1425 i2c_imx->hwdata = match; 1426 else 1427 i2c_imx->hwdata = (struct imx_i2c_hwdata *) 1428 platform_get_device_id(pdev)->driver_data; 1429 1430 /* Setup i2c_imx driver structure */ 1431 strscpy(i2c_imx->adapter.name, pdev->name, sizeof(i2c_imx->adapter.name)); 1432 i2c_imx->adapter.owner = THIS_MODULE; 1433 i2c_imx->adapter.algo = &i2c_imx_algo; 1434 i2c_imx->adapter.dev.parent = &pdev->dev; 1435 i2c_imx->adapter.nr = pdev->id; 1436 i2c_imx->adapter.dev.of_node = pdev->dev.of_node; 1437 i2c_imx->base = base; 1438 ACPI_COMPANION_SET(&i2c_imx->adapter.dev, ACPI_COMPANION(&pdev->dev)); 1439 1440 /* Get I2C clock */ 1441 i2c_imx->clk = devm_clk_get_enabled(&pdev->dev, NULL); 1442 if (IS_ERR(i2c_imx->clk)) 1443 return dev_err_probe(&pdev->dev, PTR_ERR(i2c_imx->clk), 1444 "can't get I2C clock\n"); 1445 1446 /* Init queue */ 1447 init_waitqueue_head(&i2c_imx->queue); 1448 1449 /* Set up adapter data */ 1450 i2c_set_adapdata(&i2c_imx->adapter, i2c_imx); 1451 1452 /* Set up platform driver data */ 1453 platform_set_drvdata(pdev, i2c_imx); 1454 1455 pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_TIMEOUT); 1456 pm_runtime_use_autosuspend(&pdev->dev); 1457 pm_runtime_set_active(&pdev->dev); 1458 pm_runtime_enable(&pdev->dev); 1459 1460 ret = pm_runtime_get_sync(&pdev->dev); 1461 if (ret < 0) 1462 goto rpm_disable; 1463 1464 /* Request IRQ */ 1465 ret = request_irq(irq, i2c_imx_isr, IRQF_SHARED, pdev->name, i2c_imx); 1466 if (ret) { 1467 dev_err(&pdev->dev, "can't claim irq %d\n", irq); 1468 goto rpm_disable; 1469 } 1470 1471 /* Set up clock divider */ 1472 i2c_imx->bitrate = I2C_MAX_STANDARD_MODE_FREQ; 1473 ret = of_property_read_u32(pdev->dev.of_node, 1474 "clock-frequency", &i2c_imx->bitrate); 1475 if (ret < 0 && pdata && pdata->bitrate) 1476 i2c_imx->bitrate = pdata->bitrate; 1477 i2c_imx->clk_change_nb.notifier_call = i2c_imx_clk_notifier_call; 1478 clk_notifier_register(i2c_imx->clk, &i2c_imx->clk_change_nb); 1479 i2c_imx_set_clk(i2c_imx, clk_get_rate(i2c_imx->clk)); 1480 1481 i2c_imx_reset_regs(i2c_imx); 1482 1483 /* Init optional bus recovery function */ 1484 ret = i2c_imx_init_recovery_info(i2c_imx, pdev); 1485 /* Give it another chance if pinctrl used is not ready yet */ 1486 if (ret == -EPROBE_DEFER) 1487 goto clk_notifier_unregister; 1488 1489 /* Add I2C adapter */ 1490 ret = i2c_add_numbered_adapter(&i2c_imx->adapter); 1491 if (ret < 0) 1492 goto clk_notifier_unregister; 1493 1494 pm_runtime_mark_last_busy(&pdev->dev); 1495 pm_runtime_put_autosuspend(&pdev->dev); 1496 1497 dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", irq); 1498 dev_dbg(&i2c_imx->adapter.dev, "device resources: %pR\n", res); 1499 dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n", 1500 i2c_imx->adapter.name); 1501 dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n"); 1502 1503 /* Init DMA config if supported */ 1504 i2c_imx_dma_request(i2c_imx, phy_addr); 1505 1506 return 0; /* Return OK */ 1507 1508 clk_notifier_unregister: 1509 clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb); 1510 free_irq(irq, i2c_imx); 1511 rpm_disable: 1512 pm_runtime_put_noidle(&pdev->dev); 1513 pm_runtime_disable(&pdev->dev); 1514 pm_runtime_set_suspended(&pdev->dev); 1515 pm_runtime_dont_use_autosuspend(&pdev->dev); 1516 return ret; 1517 } 1518 1519 static void i2c_imx_remove(struct platform_device *pdev) 1520 { 1521 struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev); 1522 int irq, ret; 1523 1524 ret = pm_runtime_get_sync(&pdev->dev); 1525 1526 hrtimer_cancel(&i2c_imx->slave_timer); 1527 1528 /* remove adapter */ 1529 dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n"); 1530 i2c_del_adapter(&i2c_imx->adapter); 1531 1532 if (i2c_imx->dma) 1533 i2c_imx_dma_free(i2c_imx); 1534 1535 if (ret >= 0) { 1536 /* setup chip registers to defaults */ 1537 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IADR); 1538 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IFDR); 1539 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2CR); 1540 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2SR); 1541 } 1542 1543 clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb); 1544 irq = platform_get_irq(pdev, 0); 1545 if (irq >= 0) 1546 free_irq(irq, i2c_imx); 1547 1548 pm_runtime_put_noidle(&pdev->dev); 1549 pm_runtime_disable(&pdev->dev); 1550 } 1551 1552 static int __maybe_unused i2c_imx_runtime_suspend(struct device *dev) 1553 { 1554 struct imx_i2c_struct *i2c_imx = dev_get_drvdata(dev); 1555 1556 clk_disable(i2c_imx->clk); 1557 1558 return 0; 1559 } 1560 1561 static int __maybe_unused i2c_imx_runtime_resume(struct device *dev) 1562 { 1563 struct imx_i2c_struct *i2c_imx = dev_get_drvdata(dev); 1564 int ret; 1565 1566 ret = clk_enable(i2c_imx->clk); 1567 if (ret) 1568 dev_err(dev, "can't enable I2C clock, ret=%d\n", ret); 1569 1570 return ret; 1571 } 1572 1573 static const struct dev_pm_ops i2c_imx_pm_ops = { 1574 SET_RUNTIME_PM_OPS(i2c_imx_runtime_suspend, 1575 i2c_imx_runtime_resume, NULL) 1576 }; 1577 1578 static struct platform_driver i2c_imx_driver = { 1579 .probe = i2c_imx_probe, 1580 .remove_new = i2c_imx_remove, 1581 .driver = { 1582 .name = DRIVER_NAME, 1583 .pm = &i2c_imx_pm_ops, 1584 .of_match_table = i2c_imx_dt_ids, 1585 .acpi_match_table = i2c_imx_acpi_ids, 1586 }, 1587 .id_table = imx_i2c_devtype, 1588 }; 1589 1590 static int __init i2c_adap_imx_init(void) 1591 { 1592 return platform_driver_register(&i2c_imx_driver); 1593 } 1594 subsys_initcall(i2c_adap_imx_init); 1595 1596 static void __exit i2c_adap_imx_exit(void) 1597 { 1598 platform_driver_unregister(&i2c_imx_driver); 1599 } 1600 module_exit(i2c_adap_imx_exit); 1601 1602 MODULE_LICENSE("GPL"); 1603 MODULE_AUTHOR("Darius Augulis"); 1604 MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus"); 1605 MODULE_ALIAS("platform:" DRIVER_NAME); 1606