drivers/i2c/busses/i2c-imx.c

   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  *
  21  */
  22
  23 #include <linux/clk.h>
  24 #include <linux/completion.h>
  25 #include <linux/delay.h>
  26 #include <linux/dma-mapping.h>
  27 #include <linux/dmaengine.h>
  28 #include <linux/dmapool.h>
  29 #include <linux/err.h>
  30 #include <linux/errno.h>
  31 #include <linux/gpio/consumer.h>
  32 #include <linux/i2c.h>
  33 #include <linux/init.h>
  34 #include <linux/interrupt.h>
  35 #include <linux/io.h>
  36 #include <linux/kernel.h>
  37 #include <linux/module.h>
  38 #include <linux/of.h>
  39 #include <linux/of_device.h>
  40 #include <linux/of_dma.h>
  41 #include <linux/pinctrl/consumer.h>
  42 #include <linux/platform_data/i2c-imx.h>
  43 #include <linux/platform_device.h>
  44 #include <linux/pm_runtime.h>
  45 #include <linux/sched.h>
  46 #include <linux/slab.h>
  47
  48 /* This will be the driver name the kernel reports */
  49 #define DRIVER_NAME "imx-i2c"
  50
  51 /* Default value */
  52 #define IMX_I2C_BIT_RATE        100000  /* 100kHz */
  53
  54 /*
  55  * Enable DMA if transfer byte size is bigger than this threshold.
  56  * As the hardware request, it must bigger than 4 bytes.\
  57  * I have set '16' here, maybe it's not the best but I think it's
  58  * the appropriate.
  59  */
  60 #define DMA_THRESHOLD   16
  61 #define DMA_TIMEOUT     1000
  62
  63 /* IMX I2C registers:
  64  * the I2C register offset is different between SoCs,
  65  * to provid support for all these chips, split the
  66  * register offset into a fixed base address and a
  67  * variable shift value, then the full register offset
  68  * will be calculated by
  69  * reg_off = ( reg_base_addr << reg_shift)
  70  */
  71 #define IMX_I2C_IADR    0x00    /* i2c slave address */
  72 #define IMX_I2C_IFDR    0x01    /* i2c frequency divider */
  73 #define IMX_I2C_I2CR    0x02    /* i2c control */
  74 #define IMX_I2C_I2SR    0x03    /* i2c status */
  75 #define IMX_I2C_I2DR    0x04    /* i2c transfer data */
  76
  77 #define IMX_I2C_REGSHIFT        2
  78 #define VF610_I2C_REGSHIFT      0
  79
  80 /* Bits of IMX I2C registers */
  81 #define I2SR_RXAK       0x01
  82 #define I2SR_IIF        0x02
  83 #define I2SR_SRW        0x04
  84 #define I2SR_IAL        0x10
  85 #define I2SR_IBB        0x20
  86 #define I2SR_IAAS       0x40
  87 #define I2SR_ICF        0x80
  88 #define I2CR_DMAEN      0x02
  89 #define I2CR_RSTA       0x04
  90 #define I2CR_TXAK       0x08
  91 #define I2CR_MTX        0x10
  92 #define I2CR_MSTA       0x20
  93 #define I2CR_IIEN       0x40
  94 #define I2CR_IEN        0x80
  95
  96 /* register bits different operating codes definition:
  97  * 1) I2SR: Interrupt flags clear operation differ between SoCs:
  98  * - write zero to clear(w0c) INT flag on i.MX,
  99  * - but write one to clear(w1c) INT flag on Vybrid.
 100  * 2) I2CR: I2C module enable operation also differ between SoCs:
 101  * - set I2CR_IEN bit enable the module on i.MX,
 102  * - but clear I2CR_IEN bit enable the module on Vybrid.
 103  */
 104 #define I2SR_CLR_OPCODE_W0C     0x0
 105 #define I2SR_CLR_OPCODE_W1C     (I2SR_IAL | I2SR_IIF)
 106 #define I2CR_IEN_OPCODE_0       0x0
 107 #define I2CR_IEN_OPCODE_1       I2CR_IEN
 108
 109 #define I2C_PM_TIMEOUT          10 /* ms */
 110
 111 /*
 112  * sorted list of clock divider, register value pairs
 113  * taken from table 26-5, p.26-9, Freescale i.MX
 114  * Integrated Portable System Processor Reference Manual
 115  * Document Number: MC9328MXLRM, Rev. 5.1, 06/2007
 116  *
 117  * Duplicated divider values removed from list
 118  */
 119 struct imx_i2c_clk_pair {
 120         u16     div;
 121         u16     val;
 122 };
 123
 124 static struct imx_i2c_clk_pair imx_i2c_clk_div[] = {
 125         { 22,   0x20 }, { 24,   0x21 }, { 26,   0x22 }, { 28,   0x23 },
 126         { 30,   0x00 }, { 32,   0x24 }, { 36,   0x25 }, { 40,   0x26 },
 127         { 42,   0x03 }, { 44,   0x27 }, { 48,   0x28 }, { 52,   0x05 },
 128         { 56,   0x29 }, { 60,   0x06 }, { 64,   0x2A }, { 72,   0x2B },
 129         { 80,   0x2C }, { 88,   0x09 }, { 96,   0x2D }, { 104,  0x0A },
 130         { 112,  0x2E }, { 128,  0x2F }, { 144,  0x0C }, { 160,  0x30 },
 131         { 192,  0x31 }, { 224,  0x32 }, { 240,  0x0F }, { 256,  0x33 },
 132         { 288,  0x10 }, { 320,  0x34 }, { 384,  0x35 }, { 448,  0x36 },
 133         { 480,  0x13 }, { 512,  0x37 }, { 576,  0x14 }, { 640,  0x38 },
 134         { 768,  0x39 }, { 896,  0x3A }, { 960,  0x17 }, { 1024, 0x3B },
 135         { 1152, 0x18 }, { 1280, 0x3C }, { 1536, 0x3D }, { 1792, 0x3E },
 136         { 1920, 0x1B }, { 2048, 0x3F }, { 2304, 0x1C }, { 2560, 0x1D },
 137         { 3072, 0x1E }, { 3840, 0x1F }
 138 };
 139
 140 /* Vybrid VF610 clock divider, register value pairs */
 141 static struct imx_i2c_clk_pair vf610_i2c_clk_div[] = {
 142         { 20,   0x00 }, { 22,   0x01 }, { 24,   0x02 }, { 26,   0x03 },
 143         { 28,   0x04 }, { 30,   0x05 }, { 32,   0x09 }, { 34,   0x06 },
 144         { 36,   0x0A }, { 40,   0x07 }, { 44,   0x0C }, { 48,   0x0D },
 145         { 52,   0x43 }, { 56,   0x0E }, { 60,   0x45 }, { 64,   0x12 },
 146         { 68,   0x0F }, { 72,   0x13 }, { 80,   0x14 }, { 88,   0x15 },
 147         { 96,   0x19 }, { 104,  0x16 }, { 112,  0x1A }, { 128,  0x17 },
 148         { 136,  0x4F }, { 144,  0x1C }, { 160,  0x1D }, { 176,  0x55 },
 149         { 192,  0x1E }, { 208,  0x56 }, { 224,  0x22 }, { 228,  0x24 },
 150         { 240,  0x1F }, { 256,  0x23 }, { 288,  0x5C }, { 320,  0x25 },
 151         { 384,  0x26 }, { 448,  0x2A }, { 480,  0x27 }, { 512,  0x2B },
 152         { 576,  0x2C }, { 640,  0x2D }, { 768,  0x31 }, { 896,  0x32 },
 153         { 960,  0x2F }, { 1024, 0x33 }, { 1152, 0x34 }, { 1280, 0x35 },
 154         { 1536, 0x36 }, { 1792, 0x3A }, { 1920, 0x37 }, { 2048, 0x3B },
 155         { 2304, 0x3C }, { 2560, 0x3D }, { 3072, 0x3E }, { 3584, 0x7A },
 156         { 3840, 0x3F }, { 4096, 0x7B }, { 5120, 0x7D }, { 6144, 0x7E },
 157 };
 158
 159 enum imx_i2c_type {
 160         IMX1_I2C,
 161         IMX21_I2C,
 162         VF610_I2C,
 163 };
 164
 165 struct imx_i2c_hwdata {
 166         enum imx_i2c_type       devtype;
 167         unsigned                regshift;
 168         struct imx_i2c_clk_pair *clk_div;
 169         unsigned                ndivs;
 170         unsigned                i2sr_clr_opcode;
 171         unsigned                i2cr_ien_opcode;
 172 };
 173
 174 struct imx_i2c_dma {
 175         struct dma_chan         *chan_tx;
 176         struct dma_chan         *chan_rx;
 177         struct dma_chan         *chan_using;
 178         struct completion       cmd_complete;
 179         dma_addr_t              dma_buf;
 180         unsigned int            dma_len;
 181         enum dma_transfer_direction dma_transfer_dir;
 182         enum dma_data_direction dma_data_dir;
 183 };
 184
 185 struct imx_i2c_struct {
 186         struct i2c_adapter      adapter;
 187         struct clk              *clk;
 188         struct notifier_block   clk_change_nb;
 189         void __iomem            *base;
 190         wait_queue_head_t       queue;
 191         unsigned long           i2csr;
 192         unsigned int            disable_delay;
 193         int                     stopped;
 194         unsigned int            ifdr; /* IMX_I2C_IFDR */
 195         unsigned int            cur_clk;
 196         unsigned int            bitrate;
 197         const struct imx_i2c_hwdata     *hwdata;
 198         struct i2c_bus_recovery_info rinfo;
 199
 200         struct pinctrl *pinctrl;
 201         struct pinctrl_state *pinctrl_pins_default;
 202         struct pinctrl_state *pinctrl_pins_gpio;
 203
 204         struct imx_i2c_dma      *dma;
 205 };
 206
 207 static const struct imx_i2c_hwdata imx1_i2c_hwdata = {
 208         .devtype                = IMX1_I2C,
 209         .regshift               = IMX_I2C_REGSHIFT,
 210         .clk_div                = imx_i2c_clk_div,
 211         .ndivs                  = ARRAY_SIZE(imx_i2c_clk_div),
 212         .i2sr_clr_opcode        = I2SR_CLR_OPCODE_W0C,
 213         .i2cr_ien_opcode        = I2CR_IEN_OPCODE_1,
 214
 215 };
 216
 217 static const struct imx_i2c_hwdata imx21_i2c_hwdata = {
 218         .devtype                = IMX21_I2C,
 219         .regshift               = IMX_I2C_REGSHIFT,
 220         .clk_div                = imx_i2c_clk_div,
 221         .ndivs                  = ARRAY_SIZE(imx_i2c_clk_div),
 222         .i2sr_clr_opcode        = I2SR_CLR_OPCODE_W0C,
 223         .i2cr_ien_opcode        = I2CR_IEN_OPCODE_1,
 224
 225 };
 226
 227 static struct imx_i2c_hwdata vf610_i2c_hwdata = {
 228         .devtype                = VF610_I2C,
 229         .regshift               = VF610_I2C_REGSHIFT,
 230         .clk_div                = vf610_i2c_clk_div,
 231         .ndivs                  = ARRAY_SIZE(vf610_i2c_clk_div),
 232         .i2sr_clr_opcode        = I2SR_CLR_OPCODE_W1C,
 233         .i2cr_ien_opcode        = I2CR_IEN_OPCODE_0,
 234
 235 };
 236
 237 static const struct platform_device_id imx_i2c_devtype[] = {
 238         {
 239                 .name = "imx1-i2c",
 240                 .driver_data = (kernel_ulong_t)&imx1_i2c_hwdata,
 241         }, {
 242                 .name = "imx21-i2c",
 243                 .driver_data = (kernel_ulong_t)&imx21_i2c_hwdata,
 244         }, {
 245                 /* sentinel */
 246         }
 247 };
 248 MODULE_DEVICE_TABLE(platform, imx_i2c_devtype);
 249
 250 static const struct of_device_id i2c_imx_dt_ids[] = {
 251         { .compatible = "fsl,imx1-i2c", .data = &imx1_i2c_hwdata, },
 252         { .compatible = "fsl,imx21-i2c", .data = &imx21_i2c_hwdata, },
 253         { .compatible = "fsl,vf610-i2c", .data = &vf610_i2c_hwdata, },
 254         { /* sentinel */ }
 255 };
 256 MODULE_DEVICE_TABLE(of, i2c_imx_dt_ids);
 257
 258 static inline int is_imx1_i2c(struct imx_i2c_struct *i2c_imx)
 259 {
 260         return i2c_imx->hwdata->devtype == IMX1_I2C;
 261 }
 262
 263 static inline void imx_i2c_write_reg(unsigned int val,
 264                 struct imx_i2c_struct *i2c_imx, unsigned int reg)
 265 {
 266         writeb(val, i2c_imx->base + (reg << i2c_imx->hwdata->regshift));
 267 }
 268
 269 static inline unsigned char imx_i2c_read_reg(struct imx_i2c_struct *i2c_imx,
 270                 unsigned int reg)
 271 {
 272         return readb(i2c_imx->base + (reg << i2c_imx->hwdata->regshift));
 273 }
 274
 275 /* Functions for DMA support */
 276 static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
 277                                                 dma_addr_t phy_addr)
 278 {
 279         struct imx_i2c_dma *dma;
 280         struct dma_slave_config dma_sconfig;
 281         struct device *dev = &i2c_imx->adapter.dev;
 282         int ret;
 283
 284         dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
 285         if (!dma)
 286                 return;
 287
 288         dma->chan_tx = dma_request_chan(dev, "tx");
 289         if (IS_ERR(dma->chan_tx)) {
 290                 ret = PTR_ERR(dma->chan_tx);
 291                 if (ret != -ENODEV && ret != -EPROBE_DEFER)
 292                         dev_err(dev, "can't request DMA tx channel (%d)\n", ret);
 293                 goto fail_al;
 294         }
 295
 296         dma_sconfig.dst_addr = phy_addr +
 297                                 (IMX_I2C_I2DR << i2c_imx->hwdata->regshift);
 298         dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 299         dma_sconfig.dst_maxburst = 1;
 300         dma_sconfig.direction = DMA_MEM_TO_DEV;
 301         ret = dmaengine_slave_config(dma->chan_tx, &dma_sconfig);
 302         if (ret < 0) {
 303                 dev_err(dev, "can't configure tx channel (%d)\n", ret);
 304                 goto fail_tx;
 305         }
 306
 307         dma->chan_rx = dma_request_chan(dev, "rx");
 308         if (IS_ERR(dma->chan_rx)) {
 309                 ret = PTR_ERR(dma->chan_rx);
 310                 if (ret != -ENODEV && ret != -EPROBE_DEFER)
 311                         dev_err(dev, "can't request DMA rx channel (%d)\n", ret);
 312                 goto fail_tx;
 313         }
 314
 315         dma_sconfig.src_addr = phy_addr +
 316                                 (IMX_I2C_I2DR << i2c_imx->hwdata->regshift);
 317         dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 318         dma_sconfig.src_maxburst = 1;
 319         dma_sconfig.direction = DMA_DEV_TO_MEM;
 320         ret = dmaengine_slave_config(dma->chan_rx, &dma_sconfig);
 321         if (ret < 0) {
 322                 dev_err(dev, "can't configure rx channel (%d)\n", ret);
 323                 goto fail_rx;
 324         }
 325
 326         i2c_imx->dma = dma;
 327         init_completion(&dma->cmd_complete);
 328         dev_info(dev, "using %s (tx) and %s (rx) for DMA transfers\n",
 329                 dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx));
 330
 331         return;
 332
 333 fail_rx:
 334         dma_release_channel(dma->chan_rx);
 335 fail_tx:
 336         dma_release_channel(dma->chan_tx);
 337 fail_al:
 338         devm_kfree(dev, dma);
 339 }
 340
 341 static void i2c_imx_dma_callback(void *arg)
 342 {
 343         struct imx_i2c_struct *i2c_imx = (struct imx_i2c_struct *)arg;
 344         struct imx_i2c_dma *dma = i2c_imx->dma;
 345
 346         dma_unmap_single(dma->chan_using->device->dev, dma->dma_buf,
 347                         dma->dma_len, dma->dma_data_dir);
 348         complete(&dma->cmd_complete);
 349 }
 350
 351 static int i2c_imx_dma_xfer(struct imx_i2c_struct *i2c_imx,
 352                                         struct i2c_msg *msgs)
 353 {
 354         struct imx_i2c_dma *dma = i2c_imx->dma;
 355         struct dma_async_tx_descriptor *txdesc;
 356         struct device *dev = &i2c_imx->adapter.dev;
 357         struct device *chan_dev = dma->chan_using->device->dev;
 358
 359         dma->dma_buf = dma_map_single(chan_dev, msgs->buf,
 360                                         dma->dma_len, dma->dma_data_dir);
 361         if (dma_mapping_error(chan_dev, dma->dma_buf)) {
 362                 dev_err(dev, "DMA mapping failed\n");
 363                 goto err_map;
 364         }
 365
 366         txdesc = dmaengine_prep_slave_single(dma->chan_using, dma->dma_buf,
 367                                         dma->dma_len, dma->dma_transfer_dir,
 368                                         DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 369         if (!txdesc) {
 370                 dev_err(dev, "Not able to get desc for DMA xfer\n");
 371                 goto err_desc;
 372         }
 373
 374         reinit_completion(&dma->cmd_complete);
 375         txdesc->callback = i2c_imx_dma_callback;
 376         txdesc->callback_param = i2c_imx;
 377         if (dma_submit_error(dmaengine_submit(txdesc))) {
 378                 dev_err(dev, "DMA submit failed\n");
 379                 goto err_submit;
 380         }
 381
 382         dma_async_issue_pending(dma->chan_using);
 383         return 0;
 384
 385 err_submit:
 386         dmaengine_terminate_all(dma->chan_using);
 387 err_desc:
 388         dma_unmap_single(chan_dev, dma->dma_buf,
 389                         dma->dma_len, dma->dma_data_dir);
 390 err_map:
 391         return -EINVAL;
 392 }
 393
 394 static void i2c_imx_dma_free(struct imx_i2c_struct *i2c_imx)
 395 {
 396         struct imx_i2c_dma *dma = i2c_imx->dma;
 397
 398         dma->dma_buf = 0;
 399         dma->dma_len = 0;
 400
 401         dma_release_channel(dma->chan_tx);
 402         dma->chan_tx = NULL;
 403
 404         dma_release_channel(dma->chan_rx);
 405         dma->chan_rx = NULL;
 406
 407         dma->chan_using = NULL;
 408 }
 409
 410 static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
 411 {
 412         unsigned long orig_jiffies = jiffies;
 413         unsigned int temp;
 414
 415         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 416
 417         while (1) {
 418                 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
 419
 420                 /* check for arbitration lost */
 421                 if (temp & I2SR_IAL) {
 422                         temp &= ~I2SR_IAL;
 423                         imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
 424                         return -EAGAIN;
 425                 }
 426
 427                 if (for_busy && (temp & I2SR_IBB)) {
 428                         i2c_imx->stopped = 0;
 429                         break;
 430                 }
 431                 if (!for_busy && !(temp & I2SR_IBB)) {
 432                         i2c_imx->stopped = 1;
 433                         break;
 434                 }
 435                 if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
 436                         dev_dbg(&i2c_imx->adapter.dev,
 437                                 "<%s> I2C bus is busy\n", __func__);
 438                         return -ETIMEDOUT;
 439                 }
 440                 schedule();
 441         }
 442
 443         return 0;
 444 }
 445
 446 static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
 447 {
 448         wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10);
 449
 450         if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
 451                 dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
 452                 return -ETIMEDOUT;
 453         }
 454         dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
 455         i2c_imx->i2csr = 0;
 456         return 0;
 457 }
 458
 459 static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
 460 {
 461         if (imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR) & I2SR_RXAK) {
 462                 dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
 463                 return -ENXIO;  /* No ACK */
 464         }
 465
 466         dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
 467         return 0;
 468 }
 469
 470 static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
 471                             unsigned int i2c_clk_rate)
 472 {
 473         struct imx_i2c_clk_pair *i2c_clk_div = i2c_imx->hwdata->clk_div;
 474         unsigned int div;
 475         int i;
 476
 477         /* Divider value calculation */
 478         if (i2c_imx->cur_clk == i2c_clk_rate)
 479                 return;
 480
 481         i2c_imx->cur_clk = i2c_clk_rate;
 482
 483         div = (i2c_clk_rate + i2c_imx->bitrate - 1) / i2c_imx->bitrate;
 484         if (div < i2c_clk_div[0].div)
 485                 i = 0;
 486         else if (div > i2c_clk_div[i2c_imx->hwdata->ndivs - 1].div)
 487                 i = i2c_imx->hwdata->ndivs - 1;
 488         else
 489                 for (i = 0; i2c_clk_div[i].div < div; i++)
 490                         ;
 491
 492         /* Store divider value */
 493         i2c_imx->ifdr = i2c_clk_div[i].val;
 494
 495         /*
 496          * There dummy delay is calculated.
 497          * It should be about one I2C clock period long.
 498          * This delay is used in I2C bus disable function
 499          * to fix chip hardware bug.
 500          */
 501         i2c_imx->disable_delay = (500000U * i2c_clk_div[i].div
 502                 + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
 503
 504 #ifdef CONFIG_I2C_DEBUG_BUS
 505         dev_dbg(&i2c_imx->adapter.dev, "I2C_CLK=%d, REQ DIV=%d\n",
 506                 i2c_clk_rate, div);
 507         dev_dbg(&i2c_imx->adapter.dev, "IFDR[IC]=0x%x, REAL DIV=%d\n",
 508                 i2c_clk_div[i].val, i2c_clk_div[i].div);
 509 #endif
 510 }
 511
 512 static int i2c_imx_clk_notifier_call(struct notifier_block *nb,
 513                                      unsigned long action, void *data)
 514 {
 515         struct clk_notifier_data *ndata = data;
 516         struct imx_i2c_struct *i2c_imx = container_of(nb,
 517                                                       struct imx_i2c_struct,
 518                                                       clk_change_nb);
 519
 520         if (action & POST_RATE_CHANGE)
 521                 i2c_imx_set_clk(i2c_imx, ndata->new_rate);
 522
 523         return NOTIFY_OK;
 524 }
 525
 526 static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
 527 {
 528         unsigned int temp = 0;
 529         int result;
 530
 531         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 532
 533         imx_i2c_write_reg(i2c_imx->ifdr, i2c_imx, IMX_I2C_IFDR);
 534         /* Enable I2C controller */
 535         imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR);
 536         imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode, i2c_imx, IMX_I2C_I2CR);
 537
 538         /* Wait controller to be stable */
 539         usleep_range(50, 150);
 540
 541         /* Start I2C transaction */
 542         temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
 543         temp |= I2CR_MSTA;
 544         imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 545         result = i2c_imx_bus_busy(i2c_imx, 1);
 546         if (result)
 547                 return result;
 548
 549         temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
 550         temp &= ~I2CR_DMAEN;
 551         imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 552         return result;
 553 }
 554
 555 static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
 556 {
 557         unsigned int temp = 0;
 558
 559         if (!i2c_imx->stopped) {
 560                 /* Stop I2C transaction */
 561                 dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 562                 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
 563                 temp &= ~(I2CR_MSTA | I2CR_MTX);
 564                 if (i2c_imx->dma)
 565                         temp &= ~I2CR_DMAEN;
 566                 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 567         }
 568         if (is_imx1_i2c(i2c_imx)) {
 569                 /*
 570                  * This delay caused by an i.MXL hardware bug.
 571                  * If no (or too short) delay, no "STOP" bit will be generated.
 572                  */
 573                 udelay(i2c_imx->disable_delay);
 574         }
 575
 576         if (!i2c_imx->stopped)
 577                 i2c_imx_bus_busy(i2c_imx, 0);
 578
 579         /* Disable I2C controller */
 580         temp = i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN,
 581         imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 582 }
 583
 584 static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
 585 {
 586         struct imx_i2c_struct *i2c_imx = dev_id;
 587         unsigned int temp;
 588
 589         temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
 590         if (temp & I2SR_IIF) {
 591                 /* save status register */
 592                 i2c_imx->i2csr = temp;
 593                 temp &= ~I2SR_IIF;
 594                 temp |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IIF);
 595                 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
 596                 wake_up(&i2c_imx->queue);
 597                 return IRQ_HANDLED;
 598         }
 599
 600         return IRQ_NONE;
 601 }
 602
 603 static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx,
 604                                         struct i2c_msg *msgs)
 605 {
 606         int result;
 607         unsigned long time_left;
 608         unsigned int temp = 0;
 609         unsigned long orig_jiffies = jiffies;
 610         struct imx_i2c_dma *dma = i2c_imx->dma;
 611         struct device *dev = &i2c_imx->adapter.dev;
 612
 613         dma->chan_using = dma->chan_tx;
 614         dma->dma_transfer_dir = DMA_MEM_TO_DEV;
 615         dma->dma_data_dir = DMA_TO_DEVICE;
 616         dma->dma_len = msgs->len - 1;
 617         result = i2c_imx_dma_xfer(i2c_imx, msgs);
 618         if (result)
 619                 return result;
 620
 621         temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
 622         temp |= I2CR_DMAEN;
 623         imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 624
 625         /*
 626          * Write slave address.
 627          * The first byte must be transmitted by the CPU.
 628          */
 629         imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR);
 630         time_left = wait_for_completion_timeout(
 631                                 &i2c_imx->dma->cmd_complete,
 632                                 msecs_to_jiffies(DMA_TIMEOUT));
 633         if (time_left == 0) {
 634                 dmaengine_terminate_all(dma->chan_using);
 635                 return -ETIMEDOUT;
 636         }
 637
 638         /* Waiting for transfer complete. */
 639         while (1) {
 640                 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
 641                 if (temp & I2SR_ICF)
 642                         break;
 643                 if (time_after(jiffies, orig_jiffies +
 644                                 msecs_to_jiffies(DMA_TIMEOUT))) {
 645                         dev_dbg(dev, "<%s> Timeout\n", __func__);
 646                         return -ETIMEDOUT;
 647                 }
 648                 schedule();
 649         }
 650
 651         temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
 652         temp &= ~I2CR_DMAEN;
 653         imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 654
 655         /* The last data byte must be transferred by the CPU. */
 656         imx_i2c_write_reg(msgs->buf[msgs->len-1],
 657                                 i2c_imx, IMX_I2C_I2DR);
 658         result = i2c_imx_trx_complete(i2c_imx);
 659         if (result)
 660                 return result;
 661
 662         return i2c_imx_acked(i2c_imx);
 663 }
 664
 665 static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
 666                         struct i2c_msg *msgs, bool is_lastmsg)
 667 {
 668         int result;
 669         unsigned long time_left;
 670         unsigned int temp;
 671         unsigned long orig_jiffies = jiffies;
 672         struct imx_i2c_dma *dma = i2c_imx->dma;
 673         struct device *dev = &i2c_imx->adapter.dev;
 674
 675
 676         dma->chan_using = dma->chan_rx;
 677         dma->dma_transfer_dir = DMA_DEV_TO_MEM;
 678         dma->dma_data_dir = DMA_FROM_DEVICE;
 679         /* The last two data bytes must be transferred by the CPU. */
 680         dma->dma_len = msgs->len - 2;
 681         result = i2c_imx_dma_xfer(i2c_imx, msgs);
 682         if (result)
 683                 return result;
 684
 685         time_left = wait_for_completion_timeout(
 686                                 &i2c_imx->dma->cmd_complete,
 687                                 msecs_to_jiffies(DMA_TIMEOUT));
 688         if (time_left == 0) {
 689                 dmaengine_terminate_all(dma->chan_using);
 690                 return -ETIMEDOUT;
 691         }
 692
 693         /* waiting for transfer complete. */
 694         while (1) {
 695                 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
 696                 if (temp & I2SR_ICF)
 697                         break;
 698                 if (time_after(jiffies, orig_jiffies +
 699                                 msecs_to_jiffies(DMA_TIMEOUT))) {
 700                         dev_dbg(dev, "<%s> Timeout\n", __func__);
 701                         return -ETIMEDOUT;
 702                 }
 703                 schedule();
 704         }
 705
 706         temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
 707         temp &= ~I2CR_DMAEN;
 708         imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 709
 710         /* read n-1 byte data */
 711         temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
 712         temp |= I2CR_TXAK;
 713         imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 714
 715         msgs->buf[msgs->len-2] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
 716         /* read n byte data */
 717         result = i2c_imx_trx_complete(i2c_imx);
 718         if (result)
 719                 return result;
 720
 721         if (is_lastmsg) {
 722                 /*
 723                  * It must generate STOP before read I2DR to prevent
 724                  * controller from generating another clock cycle
 725                  */
 726                 dev_dbg(dev, "<%s> clear MSTA\n", __func__);
 727                 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
 728                 temp &= ~(I2CR_MSTA | I2CR_MTX);
 729                 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 730                 i2c_imx_bus_busy(i2c_imx, 0);
 731         } else {
 732                 /*
 733                  * For i2c master receiver repeat restart operation like:
 734                  * read -> repeat MSTA -> read/write
 735                  * The controller must set MTX before read the last byte in
 736                  * the first read operation, otherwise the first read cost
 737                  * one extra clock cycle.
 738                  */
 739                 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
 740                 temp |= I2CR_MTX;
 741                 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 742         }
 743         msgs->buf[msgs->len-1] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
 744
 745         return 0;
 746 }
 747
 748 static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
 749 {
 750         int i, result;
 751
 752         dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
 753                 __func__, i2c_8bit_addr_from_msg(msgs));
 754
 755         /* write slave address */
 756         imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR);
 757         result = i2c_imx_trx_complete(i2c_imx);
 758         if (result)
 759                 return result;
 760         result = i2c_imx_acked(i2c_imx);
 761         if (result)
 762                 return result;
 763         dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
 764
 765         /* write data */
 766         for (i = 0; i < msgs->len; i++) {
 767                 dev_dbg(&i2c_imx->adapter.dev,
 768                         "<%s> write byte: B%d=0x%X\n",
 769                         __func__, i, msgs->buf[i]);
 770                 imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
 771                 result = i2c_imx_trx_complete(i2c_imx);
 772                 if (result)
 773                         return result;
 774                 result = i2c_imx_acked(i2c_imx);
 775                 if (result)
 776                         return result;
 777         }
 778         return 0;
 779 }
 780
 781 static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bool is_lastmsg)
 782 {
 783         int i, result;
 784         unsigned int temp;
 785         int block_data = msgs->flags & I2C_M_RECV_LEN;
 786         int use_dma = i2c_imx->dma && msgs->len >= DMA_THRESHOLD && !block_data;
 787
 788         dev_dbg(&i2c_imx->adapter.dev,
 789                 "<%s> write slave address: addr=0x%x\n",
 790                 __func__, i2c_8bit_addr_from_msg(msgs));
 791
 792         /* write slave address */
 793         imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR);
 794         result = i2c_imx_trx_complete(i2c_imx);
 795         if (result)
 796                 return result;
 797         result = i2c_imx_acked(i2c_imx);
 798         if (result)
 799                 return result;
 800
 801         dev_dbg(&i2c_imx->adapter.dev, "<%s> setup bus\n", __func__);
 802
 803         /* setup bus to read data */
 804         temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
 805         temp &= ~I2CR_MTX;
 806
 807         /*
 808          * Reset the I2CR_TXAK flag initially for SMBus block read since the
 809          * length is unknown
 810          */
 811         if ((msgs->len - 1) || block_data)
 812                 temp &= ~I2CR_TXAK;
 813         if (use_dma)
 814                 temp |= I2CR_DMAEN;
 815         imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 816         imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); /* dummy read */
 817
 818         dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
 819
 820         if (use_dma)
 821                 return i2c_imx_dma_read(i2c_imx, msgs, is_lastmsg);
 822
 823         /* read data */
 824         for (i = 0; i < msgs->len; i++) {
 825                 u8 len = 0;
 826
 827                 result = i2c_imx_trx_complete(i2c_imx);
 828                 if (result)
 829                         return result;
 830                 /*
 831                  * First byte is the length of remaining packet
 832                  * in the SMBus block data read. Add it to
 833                  * msgs->len.
 834                  */
 835                 if ((!i) && block_data) {
 836                         len = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
 837                         if ((len == 0) || (len > I2C_SMBUS_BLOCK_MAX))
 838                                 return -EPROTO;
 839                         dev_dbg(&i2c_imx->adapter.dev,
 840                                 "<%s> read length: 0x%X\n",
 841                                 __func__, len);
 842                         msgs->len += len;
 843                 }
 844                 if (i == (msgs->len - 1)) {
 845                         if (is_lastmsg) {
 846                                 /*
 847                                  * It must generate STOP before read I2DR to prevent
 848                                  * controller from generating another clock cycle
 849                                  */
 850                                 dev_dbg(&i2c_imx->adapter.dev,
 851                                         "<%s> clear MSTA\n", __func__);
 852                                 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
 853                                 temp &= ~(I2CR_MSTA | I2CR_MTX);
 854                                 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 855                                 i2c_imx_bus_busy(i2c_imx, 0);
 856                         } else {
 857                                 /*
 858                                  * For i2c master receiver repeat restart operation like:
 859                                  * read -> repeat MSTA -> read/write
 860                                  * The controller must set MTX before read the last byte in
 861                                  * the first read operation, otherwise the first read cost
 862                                  * one extra clock cycle.
 863                                  */
 864                                 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
 865                                 temp |= I2CR_MTX;
 866                                 imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 867                         }
 868                 } else if (i == (msgs->len - 2)) {
 869                         dev_dbg(&i2c_imx->adapter.dev,
 870                                 "<%s> set TXAK\n", __func__);
 871                         temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
 872                         temp |= I2CR_TXAK;
 873                         imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 874                 }
 875                 if ((!i) && block_data)
 876                         msgs->buf[0] = len;
 877                 else
 878                         msgs->buf[i] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
 879                 dev_dbg(&i2c_imx->adapter.dev,
 880                         "<%s> read byte: B%d=0x%X\n",
 881                         __func__, i, msgs->buf[i]);
 882         }
 883         return 0;
 884 }
 885
 886 static int i2c_imx_xfer(struct i2c_adapter *adapter,
 887                                                 struct i2c_msg *msgs, int num)
 888 {
 889         unsigned int i, temp;
 890         int result;
 891         bool is_lastmsg = false;
 892         struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
 893
 894         dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 895
 896         result = pm_runtime_get_sync(i2c_imx->adapter.dev.parent);
 897         if (result < 0)
 898                 goto out;
 899
 900         /* Start I2C transfer */
 901         result = i2c_imx_start(i2c_imx);
 902         if (result) {
 903                 if (i2c_imx->adapter.bus_recovery_info) {
 904                         i2c_recover_bus(&i2c_imx->adapter);
 905                         result = i2c_imx_start(i2c_imx);
 906                 }
 907         }
 908
 909         if (result)
 910                 goto fail0;
 911
 912         /* read/write data */
 913         for (i = 0; i < num; i++) {
 914                 if (i == num - 1)
 915                         is_lastmsg = true;
 916
 917                 if (i) {
 918                         dev_dbg(&i2c_imx->adapter.dev,
 919                                 "<%s> repeated start\n", __func__);
 920                         temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
 921                         temp |= I2CR_RSTA;
 922                         imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 923                         result = i2c_imx_bus_busy(i2c_imx, 1);
 924                         if (result)
 925                                 goto fail0;
 926                 }
 927                 dev_dbg(&i2c_imx->adapter.dev,
 928                         "<%s> transfer message: %d\n", __func__, i);
 929                 /* write/read data */
 930 #ifdef CONFIG_I2C_DEBUG_BUS
 931                 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
 932                 dev_dbg(&i2c_imx->adapter.dev,
 933                         "<%s> CONTROL: IEN=%d, IIEN=%d, MSTA=%d, MTX=%d, TXAK=%d, RSTA=%d\n",
 934                         __func__,
 935                         (temp & I2CR_IEN ? 1 : 0), (temp & I2CR_IIEN ? 1 : 0),
 936                         (temp & I2CR_MSTA ? 1 : 0), (temp & I2CR_MTX ? 1 : 0),
 937                         (temp & I2CR_TXAK ? 1 : 0), (temp & I2CR_RSTA ? 1 : 0));
 938                 temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
 939                 dev_dbg(&i2c_imx->adapter.dev,
 940                         "<%s> STATUS: ICF=%d, IAAS=%d, IBB=%d, IAL=%d, SRW=%d, IIF=%d, RXAK=%d\n",
 941                         __func__,
 942                         (temp & I2SR_ICF ? 1 : 0), (temp & I2SR_IAAS ? 1 : 0),
 943                         (temp & I2SR_IBB ? 1 : 0), (temp & I2SR_IAL ? 1 : 0),
 944                         (temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
 945                         (temp & I2SR_RXAK ? 1 : 0));
 946 #endif
 947                 if (msgs[i].flags & I2C_M_RD)
 948                         result = i2c_imx_read(i2c_imx, &msgs[i], is_lastmsg);
 949                 else {
 950                         if (i2c_imx->dma && msgs[i].len >= DMA_THRESHOLD)
 951                                 result = i2c_imx_dma_write(i2c_imx, &msgs[i]);
 952                         else
 953                                 result = i2c_imx_write(i2c_imx, &msgs[i]);
 954                 }
 955                 if (result)
 956                         goto fail0;
 957         }
 958
 959 fail0:
 960         /* Stop I2C transfer */
 961         i2c_imx_stop(i2c_imx);
 962
 963         pm_runtime_mark_last_busy(i2c_imx->adapter.dev.parent);
 964         pm_runtime_put_autosuspend(i2c_imx->adapter.dev.parent);
 965
 966 out:
 967         dev_dbg(&i2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
 968                 (result < 0) ? "error" : "success msg",
 969                         (result < 0) ? result : num);
 970         return (result < 0) ? result : num;
 971 }
 972
 973 static void i2c_imx_prepare_recovery(struct i2c_adapter *adap)
 974 {
 975         struct imx_i2c_struct *i2c_imx;
 976
 977         i2c_imx = container_of(adap, struct imx_i2c_struct, adapter);
 978
 979         pinctrl_select_state(i2c_imx->pinctrl, i2c_imx->pinctrl_pins_gpio);
 980 }
 981
 982 static void i2c_imx_unprepare_recovery(struct i2c_adapter *adap)
 983 {
 984         struct imx_i2c_struct *i2c_imx;
 985
 986         i2c_imx = container_of(adap, struct imx_i2c_struct, adapter);
 987
 988         pinctrl_select_state(i2c_imx->pinctrl, i2c_imx->pinctrl_pins_default);
 989 }
 990
 991 /*
 992  * We switch SCL and SDA to their GPIO function and do some bitbanging
 993  * for bus recovery. These alternative pinmux settings can be
 994  * described in the device tree by a separate pinctrl state "gpio". If
 995  * this is missing this is not a big problem, the only implication is
 996  * that we can't do bus recovery.
 997  */
 998 static int i2c_imx_init_recovery_info(struct imx_i2c_struct *i2c_imx,
 999                 struct platform_device *pdev)
1000 {
1001         struct i2c_bus_recovery_info *rinfo = &i2c_imx->rinfo;
1002
1003         i2c_imx->pinctrl = devm_pinctrl_get(&pdev->dev);
1004         if (!i2c_imx->pinctrl || IS_ERR(i2c_imx->pinctrl)) {
1005                 dev_info(&pdev->dev, "can't get pinctrl, bus recovery not supported\n");
1006                 return PTR_ERR(i2c_imx->pinctrl);
1007         }
1008
1009         i2c_imx->pinctrl_pins_default = pinctrl_lookup_state(i2c_imx->pinctrl,
1010                         PINCTRL_STATE_DEFAULT);
1011         i2c_imx->pinctrl_pins_gpio = pinctrl_lookup_state(i2c_imx->pinctrl,
1012                         "gpio");
1013         rinfo->sda_gpiod = devm_gpiod_get(&pdev->dev, "sda", GPIOD_IN);
1014         rinfo->scl_gpiod = devm_gpiod_get(&pdev->dev, "scl", GPIOD_OUT_HIGH_OPEN_DRAIN);
1015
1016         if (PTR_ERR(rinfo->sda_gpiod) == -EPROBE_DEFER ||
1017             PTR_ERR(rinfo->scl_gpiod) == -EPROBE_DEFER) {
1018                 return -EPROBE_DEFER;
1019         } else if (IS_ERR(rinfo->sda_gpiod) ||
1020                    IS_ERR(rinfo->scl_gpiod) ||
1021                    IS_ERR(i2c_imx->pinctrl_pins_default) ||
1022                    IS_ERR(i2c_imx->pinctrl_pins_gpio)) {
1023                 dev_dbg(&pdev->dev, "recovery information incomplete\n");
1024                 return 0;
1025         }
1026
1027         dev_dbg(&pdev->dev, "using scl%s for recovery\n",
1028                 rinfo->sda_gpiod ? ",sda" : "");
1029
1030         rinfo->prepare_recovery = i2c_imx_prepare_recovery;
1031         rinfo->unprepare_recovery = i2c_imx_unprepare_recovery;
1032         rinfo->recover_bus = i2c_generic_scl_recovery;
1033         i2c_imx->adapter.bus_recovery_info = rinfo;
1034
1035         return 0;
1036 }
1037
1038 static u32 i2c_imx_func(struct i2c_adapter *adapter)
1039 {
1040         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
1041                 | I2C_FUNC_SMBUS_READ_BLOCK_DATA;
1042 }
1043
1044 static const struct i2c_algorithm i2c_imx_algo = {
1045         .master_xfer    = i2c_imx_xfer,
1046         .functionality  = i2c_imx_func,
1047 };
1048
1049 static int i2c_imx_probe(struct platform_device *pdev)
1050 {
1051         const struct of_device_id *of_id = of_match_device(i2c_imx_dt_ids,
1052                                                            &pdev->dev);
1053         struct imx_i2c_struct *i2c_imx;
1054         struct resource *res;
1055         struct imxi2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
1056         void __iomem *base;
1057         int irq, ret;
1058         dma_addr_t phy_addr;
1059
1060         dev_dbg(&pdev->dev, "<%s>\n", __func__);
1061
1062         irq = platform_get_irq(pdev, 0);
1063         if (irq < 0) {
1064                 dev_err(&pdev->dev, "can't get irq number\n");
1065                 return irq;
1066         }
1067
1068         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1069         base = devm_ioremap_resource(&pdev->dev, res);
1070         if (IS_ERR(base))
1071                 return PTR_ERR(base);
1072
1073         phy_addr = (dma_addr_t)res->start;
1074         i2c_imx = devm_kzalloc(&pdev->dev, sizeof(*i2c_imx), GFP_KERNEL);
1075         if (!i2c_imx)
1076                 return -ENOMEM;
1077
1078         if (of_id)
1079                 i2c_imx->hwdata = of_id->data;
1080         else
1081                 i2c_imx->hwdata = (struct imx_i2c_hwdata *)
1082                                 platform_get_device_id(pdev)->driver_data;
1083
1084         /* Setup i2c_imx driver structure */
1085         strlcpy(i2c_imx->adapter.name, pdev->name, sizeof(i2c_imx->adapter.name));
1086         i2c_imx->adapter.owner          = THIS_MODULE;
1087         i2c_imx->adapter.algo           = &i2c_imx_algo;
1088         i2c_imx->adapter.dev.parent     = &pdev->dev;
1089         i2c_imx->adapter.nr             = pdev->id;
1090         i2c_imx->adapter.dev.of_node    = pdev->dev.of_node;
1091         i2c_imx->base                   = base;
1092
1093         /* Get I2C clock */
1094         i2c_imx->clk = devm_clk_get(&pdev->dev, NULL);
1095         if (IS_ERR(i2c_imx->clk)) {
1096                 if (PTR_ERR(i2c_imx->clk) != -EPROBE_DEFER)
1097                         dev_err(&pdev->dev, "can't get I2C clock\n");
1098                 return PTR_ERR(i2c_imx->clk);
1099         }
1100
1101         ret = clk_prepare_enable(i2c_imx->clk);
1102         if (ret) {
1103                 dev_err(&pdev->dev, "can't enable I2C clock, ret=%d\n", ret);
1104                 return ret;
1105         }
1106
1107         /* Request IRQ */
1108         ret = devm_request_irq(&pdev->dev, irq, i2c_imx_isr, IRQF_SHARED,
1109                                 pdev->name, i2c_imx);
1110         if (ret) {
1111                 dev_err(&pdev->dev, "can't claim irq %d\n", irq);
1112                 goto clk_disable;
1113         }
1114
1115         /* Init queue */
1116         init_waitqueue_head(&i2c_imx->queue);
1117
1118         /* Set up adapter data */
1119         i2c_set_adapdata(&i2c_imx->adapter, i2c_imx);
1120
1121         /* Set up platform driver data */
1122         platform_set_drvdata(pdev, i2c_imx);
1123
1124         pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_TIMEOUT);
1125         pm_runtime_use_autosuspend(&pdev->dev);
1126         pm_runtime_set_active(&pdev->dev);
1127         pm_runtime_enable(&pdev->dev);
1128
1129         ret = pm_runtime_get_sync(&pdev->dev);
1130         if (ret < 0)
1131                 goto rpm_disable;
1132
1133         /* Set up clock divider */
1134         i2c_imx->bitrate = IMX_I2C_BIT_RATE;
1135         ret = of_property_read_u32(pdev->dev.of_node,
1136                                    "clock-frequency", &i2c_imx->bitrate);
1137         if (ret < 0 && pdata && pdata->bitrate)
1138                 i2c_imx->bitrate = pdata->bitrate;
1139         i2c_imx->clk_change_nb.notifier_call = i2c_imx_clk_notifier_call;
1140         clk_notifier_register(i2c_imx->clk, &i2c_imx->clk_change_nb);
1141         i2c_imx_set_clk(i2c_imx, clk_get_rate(i2c_imx->clk));
1142
1143         /* Set up chip registers to defaults */
1144         imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN,
1145                         i2c_imx, IMX_I2C_I2CR);
1146         imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR);
1147
1148         /* Init optional bus recovery function */
1149         ret = i2c_imx_init_recovery_info(i2c_imx, pdev);
1150         /* Give it another chance if pinctrl used is not ready yet */
1151         if (ret == -EPROBE_DEFER)
1152                 goto clk_notifier_unregister;
1153
1154         /* Add I2C adapter */
1155         ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
1156         if (ret < 0)
1157                 goto clk_notifier_unregister;
1158
1159         pm_runtime_mark_last_busy(&pdev->dev);
1160         pm_runtime_put_autosuspend(&pdev->dev);
1161
1162         dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", irq);
1163         dev_dbg(&i2c_imx->adapter.dev, "device resources: %pR\n", res);
1164         dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
1165                 i2c_imx->adapter.name);
1166         dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
1167
1168         /* Init DMA config if supported */
1169         i2c_imx_dma_request(i2c_imx, phy_addr);
1170
1171         return 0;   /* Return OK */
1172
1173 clk_notifier_unregister:
1174         clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb);
1175 rpm_disable:
1176         pm_runtime_put_noidle(&pdev->dev);
1177         pm_runtime_disable(&pdev->dev);
1178         pm_runtime_set_suspended(&pdev->dev);
1179         pm_runtime_dont_use_autosuspend(&pdev->dev);
1180
1181 clk_disable:
1182         clk_disable_unprepare(i2c_imx->clk);
1183         return ret;
1184 }
1185
1186 static int i2c_imx_remove(struct platform_device *pdev)
1187 {
1188         struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
1189         int ret;
1190
1191         ret = pm_runtime_get_sync(&pdev->dev);
1192         if (ret < 0)
1193                 return ret;
1194
1195         /* remove adapter */
1196         dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
1197         i2c_del_adapter(&i2c_imx->adapter);
1198
1199         if (i2c_imx->dma)
1200                 i2c_imx_dma_free(i2c_imx);
1201
1202         /* setup chip registers to defaults */
1203         imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IADR);
1204         imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IFDR);
1205         imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2CR);
1206         imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2SR);
1207
1208         clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb);
1209         clk_disable_unprepare(i2c_imx->clk);
1210
1211         pm_runtime_put_noidle(&pdev->dev);
1212         pm_runtime_disable(&pdev->dev);
1213
1214         return 0;
1215 }
1216
1217 static int __maybe_unused i2c_imx_runtime_suspend(struct device *dev)
1218 {
1219         struct imx_i2c_struct *i2c_imx = dev_get_drvdata(dev);
1220
1221         clk_disable(i2c_imx->clk);
1222
1223         return 0;
1224 }
1225
1226 static int __maybe_unused i2c_imx_runtime_resume(struct device *dev)
1227 {
1228         struct imx_i2c_struct *i2c_imx = dev_get_drvdata(dev);
1229         int ret;
1230
1231         ret = clk_enable(i2c_imx->clk);
1232         if (ret)
1233                 dev_err(dev, "can't enable I2C clock, ret=%d\n", ret);
1234
1235         return ret;
1236 }
1237
1238 static const struct dev_pm_ops i2c_imx_pm_ops = {
1239         SET_RUNTIME_PM_OPS(i2c_imx_runtime_suspend,
1240                            i2c_imx_runtime_resume, NULL)
1241 };
1242
1243 static struct platform_driver i2c_imx_driver = {
1244         .probe = i2c_imx_probe,
1245         .remove = i2c_imx_remove,
1246         .driver = {
1247                 .name = DRIVER_NAME,
1248                 .pm = &i2c_imx_pm_ops,
1249                 .of_match_table = i2c_imx_dt_ids,
1250         },
1251         .id_table = imx_i2c_devtype,
1252 };
1253
1254 static int __init i2c_adap_imx_init(void)
1255 {
1256         return platform_driver_register(&i2c_imx_driver);
1257 }
1258 subsys_initcall(i2c_adap_imx_init);
1259
1260 static void __exit i2c_adap_imx_exit(void)
1261 {
1262         platform_driver_unregister(&i2c_imx_driver);
1263 }
1264 module_exit(i2c_adap_imx_exit);
1265
1266 MODULE_LICENSE("GPL");
1267 MODULE_AUTHOR("Darius Augulis");
1268 MODULE_DESCRIPTION("I2C adapter driver for IMX I2C bus");
1269 MODULE_ALIAS("platform:" DRIVER_NAME);