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 pinctrl *pinctrl; 216 struct pinctrl_state *pinctrl_pins_default; 217 struct pinctrl_state *pinctrl_pins_gpio; 218 219 struct imx_i2c_dma *dma; 220 struct i2c_client *slave; 221 enum i2c_slave_event last_slave_event; 222 223 /* For checking slave events. */ 224 spinlock_t slave_lock; 225 struct hrtimer slave_timer; 226 }; 227 228 static const struct imx_i2c_hwdata imx1_i2c_hwdata = { 229 .devtype = IMX1_I2C, 230 .regshift = IMX_I2C_REGSHIFT, 231 .clk_div = imx_i2c_clk_div, 232 .ndivs = ARRAY_SIZE(imx_i2c_clk_div), 233 .i2sr_clr_opcode = I2SR_CLR_OPCODE_W0C, 234 .i2cr_ien_opcode = I2CR_IEN_OPCODE_1, 235 236 }; 237 238 static const struct imx_i2c_hwdata imx21_i2c_hwdata = { 239 .devtype = IMX21_I2C, 240 .regshift = IMX_I2C_REGSHIFT, 241 .clk_div = imx_i2c_clk_div, 242 .ndivs = ARRAY_SIZE(imx_i2c_clk_div), 243 .i2sr_clr_opcode = I2SR_CLR_OPCODE_W0C, 244 .i2cr_ien_opcode = I2CR_IEN_OPCODE_1, 245 246 }; 247 248 static const struct imx_i2c_hwdata imx6_i2c_hwdata = { 249 .devtype = IMX21_I2C, 250 .regshift = IMX_I2C_REGSHIFT, 251 .clk_div = imx_i2c_clk_div, 252 .ndivs = ARRAY_SIZE(imx_i2c_clk_div), 253 .i2sr_clr_opcode = I2SR_CLR_OPCODE_W0C, 254 .i2cr_ien_opcode = I2CR_IEN_OPCODE_1, 255 .has_err007805 = true, 256 }; 257 258 static struct imx_i2c_hwdata vf610_i2c_hwdata = { 259 .devtype = VF610_I2C, 260 .regshift = VF610_I2C_REGSHIFT, 261 .clk_div = vf610_i2c_clk_div, 262 .ndivs = ARRAY_SIZE(vf610_i2c_clk_div), 263 .i2sr_clr_opcode = I2SR_CLR_OPCODE_W1C, 264 .i2cr_ien_opcode = I2CR_IEN_OPCODE_0, 265 266 }; 267 268 static const struct platform_device_id imx_i2c_devtype[] = { 269 { 270 .name = "imx1-i2c", 271 .driver_data = (kernel_ulong_t)&imx1_i2c_hwdata, 272 }, { 273 .name = "imx21-i2c", 274 .driver_data = (kernel_ulong_t)&imx21_i2c_hwdata, 275 }, { 276 /* sentinel */ 277 } 278 }; 279 MODULE_DEVICE_TABLE(platform, imx_i2c_devtype); 280 281 static const struct of_device_id i2c_imx_dt_ids[] = { 282 { .compatible = "fsl,imx1-i2c", .data = &imx1_i2c_hwdata, }, 283 { .compatible = "fsl,imx21-i2c", .data = &imx21_i2c_hwdata, }, 284 { .compatible = "fsl,imx6q-i2c", .data = &imx6_i2c_hwdata, }, 285 { .compatible = "fsl,imx6sl-i2c", .data = &imx6_i2c_hwdata, }, 286 { .compatible = "fsl,imx6sll-i2c", .data = &imx6_i2c_hwdata, }, 287 { .compatible = "fsl,imx6sx-i2c", .data = &imx6_i2c_hwdata, }, 288 { .compatible = "fsl,imx6ul-i2c", .data = &imx6_i2c_hwdata, }, 289 { .compatible = "fsl,imx7s-i2c", .data = &imx6_i2c_hwdata, }, 290 { .compatible = "fsl,imx8mm-i2c", .data = &imx6_i2c_hwdata, }, 291 { .compatible = "fsl,imx8mn-i2c", .data = &imx6_i2c_hwdata, }, 292 { .compatible = "fsl,imx8mp-i2c", .data = &imx6_i2c_hwdata, }, 293 { .compatible = "fsl,imx8mq-i2c", .data = &imx6_i2c_hwdata, }, 294 { .compatible = "fsl,vf610-i2c", .data = &vf610_i2c_hwdata, }, 295 { /* sentinel */ } 296 }; 297 MODULE_DEVICE_TABLE(of, i2c_imx_dt_ids); 298 299 static const struct acpi_device_id i2c_imx_acpi_ids[] = { 300 {"NXP0001", .driver_data = (kernel_ulong_t)&vf610_i2c_hwdata}, 301 { } 302 }; 303 MODULE_DEVICE_TABLE(acpi, i2c_imx_acpi_ids); 304 305 static inline int is_imx1_i2c(struct imx_i2c_struct *i2c_imx) 306 { 307 return i2c_imx->hwdata->devtype == IMX1_I2C; 308 } 309 310 static inline int is_vf610_i2c(struct imx_i2c_struct *i2c_imx) 311 { 312 return i2c_imx->hwdata->devtype == VF610_I2C; 313 } 314 315 static inline void imx_i2c_write_reg(unsigned int val, 316 struct imx_i2c_struct *i2c_imx, unsigned int reg) 317 { 318 writeb(val, i2c_imx->base + (reg << i2c_imx->hwdata->regshift)); 319 } 320 321 static inline unsigned char imx_i2c_read_reg(struct imx_i2c_struct *i2c_imx, 322 unsigned int reg) 323 { 324 return readb(i2c_imx->base + (reg << i2c_imx->hwdata->regshift)); 325 } 326 327 static void i2c_imx_clear_irq(struct imx_i2c_struct *i2c_imx, unsigned int bits) 328 { 329 unsigned int temp; 330 331 /* 332 * i2sr_clr_opcode is the value to clear all interrupts. Here we want to 333 * clear only <bits>, so we write ~i2sr_clr_opcode with just <bits> 334 * toggled. This is required because i.MX needs W0C and Vybrid uses W1C. 335 */ 336 temp = ~i2c_imx->hwdata->i2sr_clr_opcode ^ bits; 337 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR); 338 } 339 340 /* Set up i2c controller register and i2c status register to default value. */ 341 static void i2c_imx_reset_regs(struct imx_i2c_struct *i2c_imx) 342 { 343 imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN, 344 i2c_imx, IMX_I2C_I2CR); 345 i2c_imx_clear_irq(i2c_imx, I2SR_IIF | I2SR_IAL); 346 } 347 348 /* Functions for DMA support */ 349 static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx, 350 dma_addr_t phy_addr) 351 { 352 struct imx_i2c_dma *dma; 353 struct dma_slave_config dma_sconfig; 354 struct device *dev = &i2c_imx->adapter.dev; 355 int ret; 356 357 dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL); 358 if (!dma) 359 return; 360 361 dma->chan_tx = dma_request_chan(dev, "tx"); 362 if (IS_ERR(dma->chan_tx)) { 363 ret = PTR_ERR(dma->chan_tx); 364 if (ret != -ENODEV && ret != -EPROBE_DEFER) 365 dev_err(dev, "can't request DMA tx channel (%d)\n", ret); 366 goto fail_al; 367 } 368 369 dma_sconfig.dst_addr = phy_addr + 370 (IMX_I2C_I2DR << i2c_imx->hwdata->regshift); 371 dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; 372 dma_sconfig.dst_maxburst = 1; 373 dma_sconfig.direction = DMA_MEM_TO_DEV; 374 ret = dmaengine_slave_config(dma->chan_tx, &dma_sconfig); 375 if (ret < 0) { 376 dev_err(dev, "can't configure tx channel (%d)\n", ret); 377 goto fail_tx; 378 } 379 380 dma->chan_rx = dma_request_chan(dev, "rx"); 381 if (IS_ERR(dma->chan_rx)) { 382 ret = PTR_ERR(dma->chan_rx); 383 if (ret != -ENODEV && ret != -EPROBE_DEFER) 384 dev_err(dev, "can't request DMA rx channel (%d)\n", ret); 385 goto fail_tx; 386 } 387 388 dma_sconfig.src_addr = phy_addr + 389 (IMX_I2C_I2DR << i2c_imx->hwdata->regshift); 390 dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; 391 dma_sconfig.src_maxburst = 1; 392 dma_sconfig.direction = DMA_DEV_TO_MEM; 393 ret = dmaengine_slave_config(dma->chan_rx, &dma_sconfig); 394 if (ret < 0) { 395 dev_err(dev, "can't configure rx channel (%d)\n", ret); 396 goto fail_rx; 397 } 398 399 i2c_imx->dma = dma; 400 init_completion(&dma->cmd_complete); 401 dev_info(dev, "using %s (tx) and %s (rx) for DMA transfers\n", 402 dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx)); 403 404 return; 405 406 fail_rx: 407 dma_release_channel(dma->chan_rx); 408 fail_tx: 409 dma_release_channel(dma->chan_tx); 410 fail_al: 411 devm_kfree(dev, dma); 412 } 413 414 static void i2c_imx_dma_callback(void *arg) 415 { 416 struct imx_i2c_struct *i2c_imx = (struct imx_i2c_struct *)arg; 417 struct imx_i2c_dma *dma = i2c_imx->dma; 418 419 dma_unmap_single(dma->chan_using->device->dev, dma->dma_buf, 420 dma->dma_len, dma->dma_data_dir); 421 complete(&dma->cmd_complete); 422 } 423 424 static int i2c_imx_dma_xfer(struct imx_i2c_struct *i2c_imx, 425 struct i2c_msg *msgs) 426 { 427 struct imx_i2c_dma *dma = i2c_imx->dma; 428 struct dma_async_tx_descriptor *txdesc; 429 struct device *dev = &i2c_imx->adapter.dev; 430 struct device *chan_dev = dma->chan_using->device->dev; 431 432 dma->dma_buf = dma_map_single(chan_dev, msgs->buf, 433 dma->dma_len, dma->dma_data_dir); 434 if (dma_mapping_error(chan_dev, dma->dma_buf)) { 435 dev_err(dev, "DMA mapping failed\n"); 436 goto err_map; 437 } 438 439 txdesc = dmaengine_prep_slave_single(dma->chan_using, dma->dma_buf, 440 dma->dma_len, dma->dma_transfer_dir, 441 DMA_PREP_INTERRUPT | DMA_CTRL_ACK); 442 if (!txdesc) { 443 dev_err(dev, "Not able to get desc for DMA xfer\n"); 444 goto err_desc; 445 } 446 447 reinit_completion(&dma->cmd_complete); 448 txdesc->callback = i2c_imx_dma_callback; 449 txdesc->callback_param = i2c_imx; 450 if (dma_submit_error(dmaengine_submit(txdesc))) { 451 dev_err(dev, "DMA submit failed\n"); 452 goto err_submit; 453 } 454 455 dma_async_issue_pending(dma->chan_using); 456 return 0; 457 458 err_submit: 459 dmaengine_terminate_sync(dma->chan_using); 460 err_desc: 461 dma_unmap_single(chan_dev, dma->dma_buf, 462 dma->dma_len, dma->dma_data_dir); 463 err_map: 464 return -EINVAL; 465 } 466 467 static void i2c_imx_dma_free(struct imx_i2c_struct *i2c_imx) 468 { 469 struct imx_i2c_dma *dma = i2c_imx->dma; 470 471 dma->dma_buf = 0; 472 dma->dma_len = 0; 473 474 dma_release_channel(dma->chan_tx); 475 dma->chan_tx = NULL; 476 477 dma_release_channel(dma->chan_rx); 478 dma->chan_rx = NULL; 479 480 dma->chan_using = NULL; 481 } 482 483 static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool atomic) 484 { 485 unsigned long orig_jiffies = jiffies; 486 unsigned int temp; 487 488 while (1) { 489 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); 490 491 /* check for arbitration lost */ 492 if (temp & I2SR_IAL) { 493 i2c_imx_clear_irq(i2c_imx, I2SR_IAL); 494 return -EAGAIN; 495 } 496 497 if (for_busy && (temp & I2SR_IBB)) { 498 i2c_imx->stopped = 0; 499 break; 500 } 501 if (!for_busy && !(temp & I2SR_IBB)) { 502 i2c_imx->stopped = 1; 503 break; 504 } 505 if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) { 506 dev_dbg(&i2c_imx->adapter.dev, 507 "<%s> I2C bus is busy\n", __func__); 508 return -ETIMEDOUT; 509 } 510 if (atomic) 511 udelay(100); 512 else 513 schedule(); 514 } 515 516 return 0; 517 } 518 519 static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx, bool atomic) 520 { 521 if (atomic) { 522 void __iomem *addr = i2c_imx->base + (IMX_I2C_I2SR << i2c_imx->hwdata->regshift); 523 unsigned int regval; 524 525 /* 526 * The formula for the poll timeout is documented in the RM 527 * Rev.5 on page 1878: 528 * T_min = 10/F_scl 529 * Set the value hard as it is done for the non-atomic use-case. 530 * Use 10 kHz for the calculation since this is the minimum 531 * allowed SMBus frequency. Also add an offset of 100us since it 532 * turned out that the I2SR_IIF bit isn't set correctly within 533 * the minimum timeout in polling mode. 534 */ 535 readb_poll_timeout_atomic(addr, regval, regval & I2SR_IIF, 5, 1000 + 100); 536 i2c_imx->i2csr = regval; 537 i2c_imx_clear_irq(i2c_imx, I2SR_IIF | I2SR_IAL); 538 } else { 539 wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10); 540 } 541 542 if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) { 543 dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__); 544 return -ETIMEDOUT; 545 } 546 547 /* check for arbitration lost */ 548 if (i2c_imx->i2csr & I2SR_IAL) { 549 dev_dbg(&i2c_imx->adapter.dev, "<%s> Arbitration lost\n", __func__); 550 i2c_imx_clear_irq(i2c_imx, I2SR_IAL); 551 552 i2c_imx->i2csr = 0; 553 return -EAGAIN; 554 } 555 556 dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__); 557 i2c_imx->i2csr = 0; 558 return 0; 559 } 560 561 static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx) 562 { 563 if (imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR) & I2SR_RXAK) { 564 dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__); 565 return -ENXIO; /* No ACK */ 566 } 567 568 dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__); 569 return 0; 570 } 571 572 static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx, 573 unsigned int i2c_clk_rate) 574 { 575 struct imx_i2c_clk_pair *i2c_clk_div = i2c_imx->hwdata->clk_div; 576 unsigned int div; 577 int i; 578 579 if (i2c_imx->hwdata->has_err007805 && i2c_imx->bitrate > 384000) { 580 dev_dbg(&i2c_imx->adapter.dev, 581 "SoC errata ERR007805 or e7805 applies, bus frequency limited from %d Hz to 384000 Hz.\n", 582 i2c_imx->bitrate); 583 i2c_imx->bitrate = 384000; 584 } 585 586 /* Divider value calculation */ 587 if (i2c_imx->cur_clk == i2c_clk_rate) 588 return; 589 590 i2c_imx->cur_clk = i2c_clk_rate; 591 592 div = DIV_ROUND_UP(i2c_clk_rate, i2c_imx->bitrate); 593 if (div < i2c_clk_div[0].div) 594 i = 0; 595 else if (div > i2c_clk_div[i2c_imx->hwdata->ndivs - 1].div) 596 i = i2c_imx->hwdata->ndivs - 1; 597 else 598 for (i = 0; i2c_clk_div[i].div < div; i++) 599 ; 600 601 /* Store divider value */ 602 i2c_imx->ifdr = i2c_clk_div[i].val; 603 604 /* 605 * There dummy delay is calculated. 606 * It should be about one I2C clock period long. 607 * This delay is used in I2C bus disable function 608 * to fix chip hardware bug. 609 */ 610 i2c_imx->disable_delay = DIV_ROUND_UP(500000U * i2c_clk_div[i].div, 611 i2c_clk_rate / 2); 612 613 #ifdef CONFIG_I2C_DEBUG_BUS 614 dev_dbg(&i2c_imx->adapter.dev, "I2C_CLK=%d, REQ DIV=%d\n", 615 i2c_clk_rate, div); 616 dev_dbg(&i2c_imx->adapter.dev, "IFDR[IC]=0x%x, REAL DIV=%d\n", 617 i2c_clk_div[i].val, i2c_clk_div[i].div); 618 #endif 619 } 620 621 static int i2c_imx_clk_notifier_call(struct notifier_block *nb, 622 unsigned long action, void *data) 623 { 624 struct clk_notifier_data *ndata = data; 625 struct imx_i2c_struct *i2c_imx = container_of(nb, 626 struct imx_i2c_struct, 627 clk_change_nb); 628 629 if (action & POST_RATE_CHANGE) 630 i2c_imx_set_clk(i2c_imx, ndata->new_rate); 631 632 return NOTIFY_OK; 633 } 634 635 static int i2c_imx_start(struct imx_i2c_struct *i2c_imx, bool atomic) 636 { 637 unsigned int temp = 0; 638 int result; 639 640 imx_i2c_write_reg(i2c_imx->ifdr, i2c_imx, IMX_I2C_IFDR); 641 /* Enable I2C controller */ 642 imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR); 643 imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode, i2c_imx, IMX_I2C_I2CR); 644 645 /* Wait controller to be stable */ 646 if (atomic) 647 udelay(50); 648 else 649 usleep_range(50, 150); 650 651 /* Start I2C transaction */ 652 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 653 temp |= I2CR_MSTA; 654 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 655 result = i2c_imx_bus_busy(i2c_imx, 1, atomic); 656 if (result) 657 return result; 658 659 temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK; 660 if (atomic) 661 temp &= ~I2CR_IIEN; /* Disable interrupt */ 662 663 temp &= ~I2CR_DMAEN; 664 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 665 return result; 666 } 667 668 static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx, bool atomic) 669 { 670 unsigned int temp = 0; 671 672 if (!i2c_imx->stopped) { 673 /* Stop I2C transaction */ 674 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 675 if (!(temp & I2CR_MSTA)) 676 i2c_imx->stopped = 1; 677 temp &= ~(I2CR_MSTA | I2CR_MTX); 678 if (i2c_imx->dma) 679 temp &= ~I2CR_DMAEN; 680 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 681 } 682 if (is_imx1_i2c(i2c_imx)) { 683 /* 684 * This delay caused by an i.MXL hardware bug. 685 * If no (or too short) delay, no "STOP" bit will be generated. 686 */ 687 udelay(i2c_imx->disable_delay); 688 } 689 690 if (!i2c_imx->stopped) 691 i2c_imx_bus_busy(i2c_imx, 0, atomic); 692 693 /* Disable I2C controller */ 694 temp = i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN, 695 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 696 } 697 698 /* 699 * Enable bus idle interrupts 700 * Note: IBIC register will be cleared after disabled i2c module. 701 * All of layerscape series SoCs support IBIC register. 702 */ 703 static void i2c_imx_enable_bus_idle(struct imx_i2c_struct *i2c_imx) 704 { 705 if (is_vf610_i2c(i2c_imx)) { 706 unsigned int temp; 707 708 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_IBIC); 709 temp |= IBIC_BIIE; 710 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_IBIC); 711 } 712 } 713 714 static void i2c_imx_slave_event(struct imx_i2c_struct *i2c_imx, 715 enum i2c_slave_event event, u8 *val) 716 { 717 i2c_slave_event(i2c_imx->slave, event, val); 718 i2c_imx->last_slave_event = event; 719 } 720 721 static void i2c_imx_slave_finish_op(struct imx_i2c_struct *i2c_imx) 722 { 723 u8 val = 0; 724 725 while (i2c_imx->last_slave_event != I2C_SLAVE_STOP) { 726 switch (i2c_imx->last_slave_event) { 727 case I2C_SLAVE_READ_REQUESTED: 728 i2c_imx_slave_event(i2c_imx, I2C_SLAVE_READ_PROCESSED, 729 &val); 730 break; 731 732 case I2C_SLAVE_WRITE_REQUESTED: 733 case I2C_SLAVE_READ_PROCESSED: 734 case I2C_SLAVE_WRITE_RECEIVED: 735 i2c_imx_slave_event(i2c_imx, I2C_SLAVE_STOP, &val); 736 break; 737 738 case I2C_SLAVE_STOP: 739 break; 740 } 741 } 742 } 743 744 /* Returns true if the timer should be restarted, false if not. */ 745 static irqreturn_t i2c_imx_slave_handle(struct imx_i2c_struct *i2c_imx, 746 unsigned int status, unsigned int ctl) 747 { 748 u8 value = 0; 749 750 if (status & I2SR_IAL) { /* Arbitration lost */ 751 i2c_imx_clear_irq(i2c_imx, I2SR_IAL); 752 if (!(status & I2SR_IAAS)) 753 return IRQ_HANDLED; 754 } 755 756 if (!(status & I2SR_IBB)) { 757 /* No master on the bus, that could mean a stop condition. */ 758 i2c_imx_slave_finish_op(i2c_imx); 759 return IRQ_HANDLED; 760 } 761 762 if (!(status & I2SR_ICF)) 763 /* Data transfer still in progress, ignore this. */ 764 goto out; 765 766 if (status & I2SR_IAAS) { /* Addressed as a slave */ 767 i2c_imx_slave_finish_op(i2c_imx); 768 if (status & I2SR_SRW) { /* Master wants to read from us*/ 769 dev_dbg(&i2c_imx->adapter.dev, "read requested"); 770 i2c_imx_slave_event(i2c_imx, 771 I2C_SLAVE_READ_REQUESTED, &value); 772 773 /* Slave transmit */ 774 ctl |= I2CR_MTX; 775 imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); 776 777 /* Send data */ 778 imx_i2c_write_reg(value, i2c_imx, IMX_I2C_I2DR); 779 } else { /* Master wants to write to us */ 780 dev_dbg(&i2c_imx->adapter.dev, "write requested"); 781 i2c_imx_slave_event(i2c_imx, 782 I2C_SLAVE_WRITE_REQUESTED, &value); 783 784 /* Slave receive */ 785 ctl &= ~I2CR_MTX; 786 imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); 787 /* Dummy read */ 788 imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); 789 } 790 } else if (!(ctl & I2CR_MTX)) { /* Receive mode */ 791 value = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); 792 i2c_imx_slave_event(i2c_imx, 793 I2C_SLAVE_WRITE_RECEIVED, &value); 794 } else if (!(status & I2SR_RXAK)) { /* Transmit mode received ACK */ 795 ctl |= I2CR_MTX; 796 imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); 797 798 i2c_imx_slave_event(i2c_imx, 799 I2C_SLAVE_READ_PROCESSED, &value); 800 801 imx_i2c_write_reg(value, i2c_imx, IMX_I2C_I2DR); 802 } else { /* Transmit mode received NAK, operation is done */ 803 ctl &= ~I2CR_MTX; 804 imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR); 805 imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); 806 807 /* flag the last byte as processed */ 808 i2c_imx_slave_event(i2c_imx, 809 I2C_SLAVE_READ_PROCESSED, &value); 810 811 i2c_imx_slave_finish_op(i2c_imx); 812 return IRQ_HANDLED; 813 } 814 815 out: 816 /* 817 * No need to check the return value here. If it returns 0 or 818 * 1, then everything is fine. If it returns -1, then the 819 * timer is running in the handler. This will still work, 820 * though it may be redone (or already have been done) by the 821 * timer function. 822 */ 823 hrtimer_try_to_cancel(&i2c_imx->slave_timer); 824 hrtimer_forward_now(&i2c_imx->slave_timer, I2C_IMX_CHECK_DELAY); 825 hrtimer_restart(&i2c_imx->slave_timer); 826 return IRQ_HANDLED; 827 } 828 829 static enum hrtimer_restart i2c_imx_slave_timeout(struct hrtimer *t) 830 { 831 struct imx_i2c_struct *i2c_imx = container_of(t, struct imx_i2c_struct, 832 slave_timer); 833 unsigned int ctl, status; 834 unsigned long flags; 835 836 spin_lock_irqsave(&i2c_imx->slave_lock, flags); 837 status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); 838 ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 839 i2c_imx_slave_handle(i2c_imx, status, ctl); 840 spin_unlock_irqrestore(&i2c_imx->slave_lock, flags); 841 return HRTIMER_NORESTART; 842 } 843 844 static void i2c_imx_slave_init(struct imx_i2c_struct *i2c_imx) 845 { 846 int temp; 847 848 /* Set slave addr. */ 849 imx_i2c_write_reg((i2c_imx->slave->addr << 1), i2c_imx, IMX_I2C_IADR); 850 851 i2c_imx_reset_regs(i2c_imx); 852 853 /* Enable module */ 854 temp = i2c_imx->hwdata->i2cr_ien_opcode; 855 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 856 857 /* Enable interrupt from i2c module */ 858 temp |= I2CR_IIEN; 859 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 860 861 i2c_imx_enable_bus_idle(i2c_imx); 862 } 863 864 static int i2c_imx_reg_slave(struct i2c_client *client) 865 { 866 struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(client->adapter); 867 int ret; 868 869 if (i2c_imx->slave) 870 return -EBUSY; 871 872 i2c_imx->slave = client; 873 i2c_imx->last_slave_event = I2C_SLAVE_STOP; 874 875 /* Resume */ 876 ret = pm_runtime_resume_and_get(i2c_imx->adapter.dev.parent); 877 if (ret < 0) { 878 dev_err(&i2c_imx->adapter.dev, "failed to resume i2c controller"); 879 return ret; 880 } 881 882 i2c_imx_slave_init(i2c_imx); 883 884 return 0; 885 } 886 887 static int i2c_imx_unreg_slave(struct i2c_client *client) 888 { 889 struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(client->adapter); 890 int ret; 891 892 if (!i2c_imx->slave) 893 return -EINVAL; 894 895 /* Reset slave address. */ 896 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IADR); 897 898 i2c_imx_reset_regs(i2c_imx); 899 900 i2c_imx->slave = NULL; 901 902 /* Suspend */ 903 ret = pm_runtime_put_sync(i2c_imx->adapter.dev.parent); 904 if (ret < 0) 905 dev_err(&i2c_imx->adapter.dev, "failed to suspend i2c controller"); 906 907 return ret; 908 } 909 910 static irqreturn_t i2c_imx_master_isr(struct imx_i2c_struct *i2c_imx, unsigned int status) 911 { 912 /* save status register */ 913 i2c_imx->i2csr = status; 914 wake_up(&i2c_imx->queue); 915 916 return IRQ_HANDLED; 917 } 918 919 static irqreturn_t i2c_imx_isr(int irq, void *dev_id) 920 { 921 struct imx_i2c_struct *i2c_imx = dev_id; 922 unsigned int ctl, status; 923 unsigned long flags; 924 925 spin_lock_irqsave(&i2c_imx->slave_lock, flags); 926 status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); 927 ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 928 929 if (status & I2SR_IIF) { 930 i2c_imx_clear_irq(i2c_imx, I2SR_IIF); 931 if (i2c_imx->slave) { 932 if (!(ctl & I2CR_MSTA)) { 933 irqreturn_t ret; 934 935 ret = i2c_imx_slave_handle(i2c_imx, 936 status, ctl); 937 spin_unlock_irqrestore(&i2c_imx->slave_lock, 938 flags); 939 return ret; 940 } 941 i2c_imx_slave_finish_op(i2c_imx); 942 } 943 spin_unlock_irqrestore(&i2c_imx->slave_lock, flags); 944 return i2c_imx_master_isr(i2c_imx, status); 945 } 946 spin_unlock_irqrestore(&i2c_imx->slave_lock, flags); 947 948 return IRQ_NONE; 949 } 950 951 static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx, 952 struct i2c_msg *msgs) 953 { 954 int result; 955 unsigned long time_left; 956 unsigned int temp = 0; 957 unsigned long orig_jiffies = jiffies; 958 struct imx_i2c_dma *dma = i2c_imx->dma; 959 struct device *dev = &i2c_imx->adapter.dev; 960 961 dma->chan_using = dma->chan_tx; 962 dma->dma_transfer_dir = DMA_MEM_TO_DEV; 963 dma->dma_data_dir = DMA_TO_DEVICE; 964 dma->dma_len = msgs->len - 1; 965 result = i2c_imx_dma_xfer(i2c_imx, msgs); 966 if (result) 967 return result; 968 969 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 970 temp |= I2CR_DMAEN; 971 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 972 973 /* 974 * Write slave address. 975 * The first byte must be transmitted by the CPU. 976 */ 977 imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR); 978 time_left = wait_for_completion_timeout( 979 &i2c_imx->dma->cmd_complete, 980 msecs_to_jiffies(DMA_TIMEOUT)); 981 if (time_left == 0) { 982 dmaengine_terminate_sync(dma->chan_using); 983 return -ETIMEDOUT; 984 } 985 986 /* Waiting for transfer complete. */ 987 while (1) { 988 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); 989 if (temp & I2SR_ICF) 990 break; 991 if (time_after(jiffies, orig_jiffies + 992 msecs_to_jiffies(DMA_TIMEOUT))) { 993 dev_dbg(dev, "<%s> Timeout\n", __func__); 994 return -ETIMEDOUT; 995 } 996 schedule(); 997 } 998 999 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1000 temp &= ~I2CR_DMAEN; 1001 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 1002 1003 /* The last data byte must be transferred by the CPU. */ 1004 imx_i2c_write_reg(msgs->buf[msgs->len-1], 1005 i2c_imx, IMX_I2C_I2DR); 1006 result = i2c_imx_trx_complete(i2c_imx, false); 1007 if (result) 1008 return result; 1009 1010 return i2c_imx_acked(i2c_imx); 1011 } 1012 1013 static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx, 1014 struct i2c_msg *msgs, bool is_lastmsg) 1015 { 1016 int result; 1017 unsigned long time_left; 1018 unsigned int temp; 1019 unsigned long orig_jiffies = jiffies; 1020 struct imx_i2c_dma *dma = i2c_imx->dma; 1021 struct device *dev = &i2c_imx->adapter.dev; 1022 1023 1024 dma->chan_using = dma->chan_rx; 1025 dma->dma_transfer_dir = DMA_DEV_TO_MEM; 1026 dma->dma_data_dir = DMA_FROM_DEVICE; 1027 /* The last two data bytes must be transferred by the CPU. */ 1028 dma->dma_len = msgs->len - 2; 1029 result = i2c_imx_dma_xfer(i2c_imx, msgs); 1030 if (result) 1031 return result; 1032 1033 time_left = wait_for_completion_timeout( 1034 &i2c_imx->dma->cmd_complete, 1035 msecs_to_jiffies(DMA_TIMEOUT)); 1036 if (time_left == 0) { 1037 dmaengine_terminate_sync(dma->chan_using); 1038 return -ETIMEDOUT; 1039 } 1040 1041 /* waiting for transfer complete. */ 1042 while (1) { 1043 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); 1044 if (temp & I2SR_ICF) 1045 break; 1046 if (time_after(jiffies, orig_jiffies + 1047 msecs_to_jiffies(DMA_TIMEOUT))) { 1048 dev_dbg(dev, "<%s> Timeout\n", __func__); 1049 return -ETIMEDOUT; 1050 } 1051 schedule(); 1052 } 1053 1054 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1055 temp &= ~I2CR_DMAEN; 1056 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 1057 1058 /* read n-1 byte data */ 1059 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1060 temp |= I2CR_TXAK; 1061 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 1062 1063 msgs->buf[msgs->len-2] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); 1064 /* read n byte data */ 1065 result = i2c_imx_trx_complete(i2c_imx, false); 1066 if (result) 1067 return result; 1068 1069 if (is_lastmsg) { 1070 /* 1071 * It must generate STOP before read I2DR to prevent 1072 * controller from generating another clock cycle 1073 */ 1074 dev_dbg(dev, "<%s> clear MSTA\n", __func__); 1075 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1076 if (!(temp & I2CR_MSTA)) 1077 i2c_imx->stopped = 1; 1078 temp &= ~(I2CR_MSTA | I2CR_MTX); 1079 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 1080 if (!i2c_imx->stopped) 1081 i2c_imx_bus_busy(i2c_imx, 0, false); 1082 } else { 1083 /* 1084 * For i2c master receiver repeat restart operation like: 1085 * read -> repeat MSTA -> read/write 1086 * The controller must set MTX before read the last byte in 1087 * the first read operation, otherwise the first read cost 1088 * one extra clock cycle. 1089 */ 1090 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1091 temp |= I2CR_MTX; 1092 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 1093 } 1094 msgs->buf[msgs->len-1] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); 1095 1096 return 0; 1097 } 1098 1099 static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, 1100 bool atomic) 1101 { 1102 int i, result; 1103 1104 dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n", 1105 __func__, i2c_8bit_addr_from_msg(msgs)); 1106 1107 /* write slave address */ 1108 imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR); 1109 result = i2c_imx_trx_complete(i2c_imx, atomic); 1110 if (result) 1111 return result; 1112 result = i2c_imx_acked(i2c_imx); 1113 if (result) 1114 return result; 1115 dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__); 1116 1117 /* write data */ 1118 for (i = 0; i < msgs->len; i++) { 1119 dev_dbg(&i2c_imx->adapter.dev, 1120 "<%s> write byte: B%d=0x%X\n", 1121 __func__, i, msgs->buf[i]); 1122 imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR); 1123 result = i2c_imx_trx_complete(i2c_imx, atomic); 1124 if (result) 1125 return result; 1126 result = i2c_imx_acked(i2c_imx); 1127 if (result) 1128 return result; 1129 } 1130 return 0; 1131 } 1132 1133 static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, 1134 bool is_lastmsg, bool atomic) 1135 { 1136 int i, result; 1137 unsigned int temp; 1138 int block_data = msgs->flags & I2C_M_RECV_LEN; 1139 int use_dma = i2c_imx->dma && msgs->flags & I2C_M_DMA_SAFE && 1140 msgs->len >= DMA_THRESHOLD && !block_data; 1141 1142 dev_dbg(&i2c_imx->adapter.dev, 1143 "<%s> write slave address: addr=0x%x\n", 1144 __func__, i2c_8bit_addr_from_msg(msgs)); 1145 1146 /* write slave address */ 1147 imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR); 1148 result = i2c_imx_trx_complete(i2c_imx, atomic); 1149 if (result) 1150 return result; 1151 result = i2c_imx_acked(i2c_imx); 1152 if (result) 1153 return result; 1154 1155 dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__); 1156 1157 /* setup bus to read data */ 1158 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1159 temp &= ~I2CR_MTX; 1160 1161 /* 1162 * Reset the I2CR_TXAK flag initially for SMBus block read since the 1163 * length is unknown 1164 */ 1165 if ((msgs->len - 1) || block_data) 1166 temp &= ~I2CR_TXAK; 1167 if (use_dma) 1168 temp |= I2CR_DMAEN; 1169 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 1170 imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); /* dummy read */ 1171 1172 dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__); 1173 1174 if (use_dma) 1175 return i2c_imx_dma_read(i2c_imx, msgs, is_lastmsg); 1176 1177 /* read data */ 1178 for (i = 0; i < msgs->len; i++) { 1179 u8 len = 0; 1180 1181 result = i2c_imx_trx_complete(i2c_imx, atomic); 1182 if (result) 1183 return result; 1184 /* 1185 * First byte is the length of remaining packet 1186 * in the SMBus block data read. Add it to 1187 * msgs->len. 1188 */ 1189 if ((!i) && block_data) { 1190 len = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); 1191 if ((len == 0) || (len > I2C_SMBUS_BLOCK_MAX)) 1192 return -EPROTO; 1193 dev_dbg(&i2c_imx->adapter.dev, 1194 "<%s> read length: 0x%X\n", 1195 __func__, len); 1196 msgs->len += len; 1197 } 1198 if (i == (msgs->len - 1)) { 1199 if (is_lastmsg) { 1200 /* 1201 * It must generate STOP before read I2DR to prevent 1202 * controller from generating another clock cycle 1203 */ 1204 dev_dbg(&i2c_imx->adapter.dev, 1205 "<%s> clear MSTA\n", __func__); 1206 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1207 if (!(temp & I2CR_MSTA)) 1208 i2c_imx->stopped = 1; 1209 temp &= ~(I2CR_MSTA | I2CR_MTX); 1210 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 1211 if (!i2c_imx->stopped) 1212 i2c_imx_bus_busy(i2c_imx, 0, atomic); 1213 } else { 1214 /* 1215 * For i2c master receiver repeat restart operation like: 1216 * read -> repeat MSTA -> read/write 1217 * The controller must set MTX before read the last byte in 1218 * the first read operation, otherwise the first read cost 1219 * one extra clock cycle. 1220 */ 1221 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1222 temp |= I2CR_MTX; 1223 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 1224 } 1225 } else if (i == (msgs->len - 2)) { 1226 dev_dbg(&i2c_imx->adapter.dev, 1227 "<%s> set TXAK\n", __func__); 1228 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1229 temp |= I2CR_TXAK; 1230 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 1231 } 1232 if ((!i) && block_data) 1233 msgs->buf[0] = len; 1234 else 1235 msgs->buf[i] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); 1236 dev_dbg(&i2c_imx->adapter.dev, 1237 "<%s> read byte: B%d=0x%X\n", 1238 __func__, i, msgs->buf[i]); 1239 } 1240 return 0; 1241 } 1242 1243 static int i2c_imx_xfer_common(struct i2c_adapter *adapter, 1244 struct i2c_msg *msgs, int num, bool atomic) 1245 { 1246 unsigned int i, temp; 1247 int result; 1248 bool is_lastmsg = false; 1249 struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter); 1250 1251 /* Start I2C transfer */ 1252 result = i2c_imx_start(i2c_imx, atomic); 1253 if (result) { 1254 /* 1255 * Bus recovery uses gpiod_get_value_cansleep() which is not 1256 * allowed within atomic context. 1257 */ 1258 if (!atomic && i2c_imx->adapter.bus_recovery_info) { 1259 i2c_recover_bus(&i2c_imx->adapter); 1260 result = i2c_imx_start(i2c_imx, atomic); 1261 } 1262 } 1263 1264 if (result) 1265 goto fail0; 1266 1267 /* read/write data */ 1268 for (i = 0; i < num; i++) { 1269 if (i == num - 1) 1270 is_lastmsg = true; 1271 1272 if (i) { 1273 dev_dbg(&i2c_imx->adapter.dev, 1274 "<%s> repeated start\n", __func__); 1275 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1276 temp |= I2CR_RSTA; 1277 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); 1278 result = i2c_imx_bus_busy(i2c_imx, 1, atomic); 1279 if (result) 1280 goto fail0; 1281 } 1282 dev_dbg(&i2c_imx->adapter.dev, 1283 "<%s> transfer message: %d\n", __func__, i); 1284 /* write/read data */ 1285 #ifdef CONFIG_I2C_DEBUG_BUS 1286 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR); 1287 dev_dbg(&i2c_imx->adapter.dev, 1288 "<%s> CONTROL: IEN=%d, IIEN=%d, MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n", 1289 __func__, 1290 (temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0), 1291 (temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0), 1292 (temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0)); 1293 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); 1294 dev_dbg(&i2c_imx->adapter.dev, 1295 "<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n", 1296 __func__, 1297 (temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0), 1298 (temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0), 1299 (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0), 1300 (temp & I2SR_RXAK ? 1 : 0)); 1301 #endif 1302 if (msgs[i].flags & I2C_M_RD) { 1303 result = i2c_imx_read(i2c_imx, &msgs[i], is_lastmsg, atomic); 1304 } else { 1305 if (!atomic && 1306 i2c_imx->dma && msgs[i].len >= DMA_THRESHOLD && 1307 msgs[i].flags & I2C_M_DMA_SAFE) 1308 result = i2c_imx_dma_write(i2c_imx, &msgs[i]); 1309 else 1310 result = i2c_imx_write(i2c_imx, &msgs[i], atomic); 1311 } 1312 if (result) 1313 goto fail0; 1314 } 1315 1316 fail0: 1317 /* Stop I2C transfer */ 1318 i2c_imx_stop(i2c_imx, atomic); 1319 1320 dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__, 1321 (result < 0) ? "error" : "success msg", 1322 (result < 0) ? result : num); 1323 /* After data is transferred, switch to slave mode(as a receiver) */ 1324 if (i2c_imx->slave) 1325 i2c_imx_slave_init(i2c_imx); 1326 1327 return (result < 0) ? result : num; 1328 } 1329 1330 static int i2c_imx_xfer(struct i2c_adapter *adapter, 1331 struct i2c_msg *msgs, int num) 1332 { 1333 struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter); 1334 int result; 1335 1336 result = pm_runtime_resume_and_get(i2c_imx->adapter.dev.parent); 1337 if (result < 0) 1338 return result; 1339 1340 result = i2c_imx_xfer_common(adapter, msgs, num, false); 1341 1342 pm_runtime_mark_last_busy(i2c_imx->adapter.dev.parent); 1343 pm_runtime_put_autosuspend(i2c_imx->adapter.dev.parent); 1344 1345 return result; 1346 } 1347 1348 static int i2c_imx_xfer_atomic(struct i2c_adapter *adapter, 1349 struct i2c_msg *msgs, int num) 1350 { 1351 struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter); 1352 int result; 1353 1354 result = clk_enable(i2c_imx->clk); 1355 if (result) 1356 return result; 1357 1358 result = i2c_imx_xfer_common(adapter, msgs, num, true); 1359 1360 clk_disable(i2c_imx->clk); 1361 1362 return result; 1363 } 1364 1365 static void i2c_imx_prepare_recovery(struct i2c_adapter *adap) 1366 { 1367 struct imx_i2c_struct *i2c_imx; 1368 1369 i2c_imx = container_of(adap, struct imx_i2c_struct, adapter); 1370 1371 pinctrl_select_state(i2c_imx->pinctrl, i2c_imx->pinctrl_pins_gpio); 1372 } 1373 1374 static void i2c_imx_unprepare_recovery(struct i2c_adapter *adap) 1375 { 1376 struct imx_i2c_struct *i2c_imx; 1377 1378 i2c_imx = container_of(adap, struct imx_i2c_struct, adapter); 1379 1380 pinctrl_select_state(i2c_imx->pinctrl, i2c_imx->pinctrl_pins_default); 1381 } 1382 1383 /* 1384 * We switch SCL and SDA to their GPIO function and do some bitbanging 1385 * for bus recovery. These alternative pinmux settings can be 1386 * described in the device tree by a separate pinctrl state "gpio". If 1387 * this is missing this is not a big problem, the only implication is 1388 * that we can't do bus recovery. 1389 */ 1390 static int i2c_imx_init_recovery_info(struct imx_i2c_struct *i2c_imx, 1391 struct platform_device *pdev) 1392 { 1393 struct i2c_bus_recovery_info *rinfo = &i2c_imx->rinfo; 1394 1395 i2c_imx->pinctrl = devm_pinctrl_get(&pdev->dev); 1396 if (!i2c_imx->pinctrl) { 1397 dev_info(&pdev->dev, "pinctrl unavailable, bus recovery not supported\n"); 1398 return 0; 1399 } 1400 if (IS_ERR(i2c_imx->pinctrl)) { 1401 dev_info(&pdev->dev, "can't get pinctrl, bus recovery not supported\n"); 1402 return PTR_ERR(i2c_imx->pinctrl); 1403 } 1404 1405 i2c_imx->pinctrl_pins_default = pinctrl_lookup_state(i2c_imx->pinctrl, 1406 PINCTRL_STATE_DEFAULT); 1407 i2c_imx->pinctrl_pins_gpio = pinctrl_lookup_state(i2c_imx->pinctrl, 1408 "gpio"); 1409 rinfo->sda_gpiod = devm_gpiod_get_optional(&pdev->dev, "sda", GPIOD_IN); 1410 rinfo->scl_gpiod = devm_gpiod_get(&pdev->dev, "scl", GPIOD_OUT_HIGH_OPEN_DRAIN); 1411 1412 if (PTR_ERR(rinfo->sda_gpiod) == -EPROBE_DEFER || 1413 PTR_ERR(rinfo->scl_gpiod) == -EPROBE_DEFER) { 1414 return -EPROBE_DEFER; 1415 } else if (IS_ERR(rinfo->sda_gpiod) || 1416 IS_ERR(rinfo->scl_gpiod) || 1417 IS_ERR(i2c_imx->pinctrl_pins_default) || 1418 IS_ERR(i2c_imx->pinctrl_pins_gpio)) { 1419 dev_dbg(&pdev->dev, "recovery information incomplete\n"); 1420 return 0; 1421 } 1422 1423 dev_dbg(&pdev->dev, "using scl%s for recovery\n", 1424 rinfo->sda_gpiod ? ",sda" : ""); 1425 1426 rinfo->prepare_recovery = i2c_imx_prepare_recovery; 1427 rinfo->unprepare_recovery = i2c_imx_unprepare_recovery; 1428 rinfo->recover_bus = i2c_generic_scl_recovery; 1429 i2c_imx->adapter.bus_recovery_info = rinfo; 1430 1431 return 0; 1432 } 1433 1434 static u32 i2c_imx_func(struct i2c_adapter *adapter) 1435 { 1436 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL 1437 | I2C_FUNC_SMBUS_READ_BLOCK_DATA; 1438 } 1439 1440 static const struct i2c_algorithm i2c_imx_algo = { 1441 .master_xfer = i2c_imx_xfer, 1442 .master_xfer_atomic = i2c_imx_xfer_atomic, 1443 .functionality = i2c_imx_func, 1444 .reg_slave = i2c_imx_reg_slave, 1445 .unreg_slave = i2c_imx_unreg_slave, 1446 }; 1447 1448 static int i2c_imx_probe(struct platform_device *pdev) 1449 { 1450 struct imx_i2c_struct *i2c_imx; 1451 struct resource *res; 1452 struct imxi2c_platform_data *pdata = dev_get_platdata(&pdev->dev); 1453 void __iomem *base; 1454 int irq, ret; 1455 dma_addr_t phy_addr; 1456 const struct imx_i2c_hwdata *match; 1457 1458 irq = platform_get_irq(pdev, 0); 1459 if (irq < 0) 1460 return irq; 1461 1462 base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); 1463 if (IS_ERR(base)) 1464 return PTR_ERR(base); 1465 1466 phy_addr = (dma_addr_t)res->start; 1467 i2c_imx = devm_kzalloc(&pdev->dev, sizeof(*i2c_imx), GFP_KERNEL); 1468 if (!i2c_imx) 1469 return -ENOMEM; 1470 1471 spin_lock_init(&i2c_imx->slave_lock); 1472 hrtimer_init(&i2c_imx->slave_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); 1473 i2c_imx->slave_timer.function = i2c_imx_slave_timeout; 1474 1475 match = device_get_match_data(&pdev->dev); 1476 if (match) 1477 i2c_imx->hwdata = match; 1478 else 1479 i2c_imx->hwdata = (struct imx_i2c_hwdata *) 1480 platform_get_device_id(pdev)->driver_data; 1481 1482 /* Setup i2c_imx driver structure */ 1483 strscpy(i2c_imx->adapter.name, pdev->name, sizeof(i2c_imx->adapter.name)); 1484 i2c_imx->adapter.owner = THIS_MODULE; 1485 i2c_imx->adapter.algo = &i2c_imx_algo; 1486 i2c_imx->adapter.dev.parent = &pdev->dev; 1487 i2c_imx->adapter.nr = pdev->id; 1488 i2c_imx->adapter.dev.of_node = pdev->dev.of_node; 1489 i2c_imx->base = base; 1490 ACPI_COMPANION_SET(&i2c_imx->adapter.dev, ACPI_COMPANION(&pdev->dev)); 1491 1492 /* Get I2C clock */ 1493 i2c_imx->clk = devm_clk_get_enabled(&pdev->dev, NULL); 1494 if (IS_ERR(i2c_imx->clk)) 1495 return dev_err_probe(&pdev->dev, PTR_ERR(i2c_imx->clk), 1496 "can't get I2C clock\n"); 1497 1498 /* Init queue */ 1499 init_waitqueue_head(&i2c_imx->queue); 1500 1501 /* Set up adapter data */ 1502 i2c_set_adapdata(&i2c_imx->adapter, i2c_imx); 1503 1504 /* Set up platform driver data */ 1505 platform_set_drvdata(pdev, i2c_imx); 1506 1507 pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_TIMEOUT); 1508 pm_runtime_use_autosuspend(&pdev->dev); 1509 pm_runtime_set_active(&pdev->dev); 1510 pm_runtime_enable(&pdev->dev); 1511 1512 ret = pm_runtime_get_sync(&pdev->dev); 1513 if (ret < 0) 1514 goto rpm_disable; 1515 1516 /* Request IRQ */ 1517 ret = request_irq(irq, i2c_imx_isr, IRQF_SHARED, pdev->name, i2c_imx); 1518 if (ret) { 1519 dev_err(&pdev->dev, "can't claim irq %d\n", irq); 1520 goto rpm_disable; 1521 } 1522 1523 /* Set up clock divider */ 1524 i2c_imx->bitrate = I2C_MAX_STANDARD_MODE_FREQ; 1525 ret = of_property_read_u32(pdev->dev.of_node, 1526 "clock-frequency", &i2c_imx->bitrate); 1527 if (ret < 0 && pdata && pdata->bitrate) 1528 i2c_imx->bitrate = pdata->bitrate; 1529 i2c_imx->clk_change_nb.notifier_call = i2c_imx_clk_notifier_call; 1530 clk_notifier_register(i2c_imx->clk, &i2c_imx->clk_change_nb); 1531 i2c_imx_set_clk(i2c_imx, clk_get_rate(i2c_imx->clk)); 1532 1533 i2c_imx_reset_regs(i2c_imx); 1534 1535 /* Init optional bus recovery function */ 1536 ret = i2c_imx_init_recovery_info(i2c_imx, pdev); 1537 /* Give it another chance if pinctrl used is not ready yet */ 1538 if (ret == -EPROBE_DEFER) 1539 goto clk_notifier_unregister; 1540 1541 /* Add I2C adapter */ 1542 ret = i2c_add_numbered_adapter(&i2c_imx->adapter); 1543 if (ret < 0) 1544 goto clk_notifier_unregister; 1545 1546 pm_runtime_mark_last_busy(&pdev->dev); 1547 pm_runtime_put_autosuspend(&pdev->dev); 1548 1549 dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", irq); 1550 dev_dbg(&i2c_imx->adapter.dev, "device resources: %pR\n", res); 1551 dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n", 1552 i2c_imx->adapter.name); 1553 dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n"); 1554 1555 /* Init DMA config if supported */ 1556 i2c_imx_dma_request(i2c_imx, phy_addr); 1557 1558 return 0; /* Return OK */ 1559 1560 clk_notifier_unregister: 1561 clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb); 1562 free_irq(irq, i2c_imx); 1563 rpm_disable: 1564 pm_runtime_put_noidle(&pdev->dev); 1565 pm_runtime_disable(&pdev->dev); 1566 pm_runtime_set_suspended(&pdev->dev); 1567 pm_runtime_dont_use_autosuspend(&pdev->dev); 1568 return ret; 1569 } 1570 1571 static void i2c_imx_remove(struct platform_device *pdev) 1572 { 1573 struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev); 1574 int irq, ret; 1575 1576 ret = pm_runtime_get_sync(&pdev->dev); 1577 1578 hrtimer_cancel(&i2c_imx->slave_timer); 1579 1580 /* remove adapter */ 1581 dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n"); 1582 i2c_del_adapter(&i2c_imx->adapter); 1583 1584 if (i2c_imx->dma) 1585 i2c_imx_dma_free(i2c_imx); 1586 1587 if (ret >= 0) { 1588 /* setup chip registers to defaults */ 1589 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IADR); 1590 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IFDR); 1591 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2CR); 1592 imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2SR); 1593 } 1594 1595 clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb); 1596 irq = platform_get_irq(pdev, 0); 1597 if (irq >= 0) 1598 free_irq(irq, i2c_imx); 1599 1600 pm_runtime_put_noidle(&pdev->dev); 1601 pm_runtime_disable(&pdev->dev); 1602 } 1603 1604 static int __maybe_unused i2c_imx_runtime_suspend(struct device *dev) 1605 { 1606 struct imx_i2c_struct *i2c_imx = dev_get_drvdata(dev); 1607 1608 clk_disable(i2c_imx->clk); 1609 1610 return 0; 1611 } 1612 1613 static int __maybe_unused i2c_imx_runtime_resume(struct device *dev) 1614 { 1615 struct imx_i2c_struct *i2c_imx = dev_get_drvdata(dev); 1616 int ret; 1617 1618 ret = clk_enable(i2c_imx->clk); 1619 if (ret) 1620 dev_err(dev, "can't enable I2C clock, ret=%d\n", ret); 1621 1622 return ret; 1623 } 1624 1625 static const struct dev_pm_ops i2c_imx_pm_ops = { 1626 SET_RUNTIME_PM_OPS(i2c_imx_runtime_suspend, 1627 i2c_imx_runtime_resume, NULL) 1628 }; 1629 1630 static struct platform_driver i2c_imx_driver = { 1631 .probe = i2c_imx_probe, 1632 .remove_new = i2c_imx_remove, 1633 .driver = { 1634 .name = DRIVER_NAME, 1635 .pm = &i2c_imx_pm_ops, 1636 .of_match_table = i2c_imx_dt_ids, 1637 .acpi_match_table = i2c_imx_acpi_ids, 1638 }, 1639 .id_table = imx_i2c_devtype, 1640 }; 1641 1642 static int __init i2c_adap_imx_init(void) 1643 { 1644 return platform_driver_register(&i2c_imx_driver); 1645 } 1646 subsys_initcall(i2c_adap_imx_init); 1647 1648 static void __exit i2c_adap_imx_exit(void) 1649 { 1650 platform_driver_unregister(&i2c_imx_driver); 1651 } 1652 module_exit(i2c_adap_imx_exit); 1653 1654 MODULE_LICENSE("GPL"); 1655 MODULE_AUTHOR("Darius Augulis"); 1656 MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus"); 1657 MODULE_ALIAS("platform:" DRIVER_NAME); 1658