drivers/i2c/busses/i2c-cpm.c

   1 /*
   2  * Freescale CPM1/CPM2 I2C interface.
   3  * Copyright (c) 1999 Dan Malek (dmalek@jlc.net).
   4  *
   5  * moved into proper i2c interface;
   6  * Brad Parker (brad@heeltoe.com)
   7  *
   8  * Parts from dbox2_i2c.c (cvs.tuxbox.org)
   9  * (C) 2000-2001 Felix Domke (tmbinc@gmx.net), Gillem (htoa@gmx.net)
  10  *
  11  * (C) 2007 Montavista Software, Inc.
  12  * Vitaly Bordug <vitb@kernel.crashing.org>
  13  *
  14  * Converted to of_platform_device. Renamed to i2c-cpm.c.
  15  * (C) 2007,2008 Jochen Friedrich <jochen@scram.de>
  16  *
  17  *  This program is free software; you can redistribute it and/or modify
  18  *  it under the terms of the GNU General Public License as published by
  19  *  the Free Software Foundation; either version 2 of the License, or
  20  *  (at your option) any later version.
  21  *
  22  *  This program is distributed in the hope that it will be useful,
  23  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  *  GNU General Public License for more details.
  26  */
  27
  28 #include <linux/kernel.h>
  29 #include <linux/module.h>
  30 #include <linux/delay.h>
  31 #include <linux/slab.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/errno.h>
  34 #include <linux/stddef.h>
  35 #include <linux/i2c.h>
  36 #include <linux/io.h>
  37 #include <linux/dma-mapping.h>
  38 #include <linux/of_address.h>
  39 #include <linux/of_device.h>
  40 #include <linux/of_irq.h>
  41 #include <linux/of_platform.h>
  42 #include <sysdev/fsl_soc.h>
  43 #include <asm/cpm.h>
  44
  45 /* Try to define this if you have an older CPU (earlier than rev D4) */
  46 /* However, better use a GPIO based bitbang driver in this case :/   */
  47 #undef  I2C_CHIP_ERRATA
  48
  49 #define CPM_MAX_READ    513
  50 #define CPM_MAXBD       4
  51
  52 #define I2C_EB                  (0x10) /* Big endian mode */
  53 #define I2C_EB_CPM2             (0x30) /* Big endian mode, memory snoop */
  54
  55 #define DPRAM_BASE              ((u8 __iomem __force *)cpm_muram_addr(0))
  56
  57 /* I2C parameter RAM. */
  58 struct i2c_ram {
  59         ushort  rbase;          /* Rx Buffer descriptor base address */
  60         ushort  tbase;          /* Tx Buffer descriptor base address */
  61         u_char  rfcr;           /* Rx function code */
  62         u_char  tfcr;           /* Tx function code */
  63         ushort  mrblr;          /* Max receive buffer length */
  64         uint    rstate;         /* Internal */
  65         uint    rdp;            /* Internal */
  66         ushort  rbptr;          /* Rx Buffer descriptor pointer */
  67         ushort  rbc;            /* Internal */
  68         uint    rxtmp;          /* Internal */
  69         uint    tstate;         /* Internal */
  70         uint    tdp;            /* Internal */
  71         ushort  tbptr;          /* Tx Buffer descriptor pointer */
  72         ushort  tbc;            /* Internal */
  73         uint    txtmp;          /* Internal */
  74         char    res1[4];        /* Reserved */
  75         ushort  rpbase;         /* Relocation pointer */
  76         char    res2[2];        /* Reserved */
  77         /* The following elements are only for CPM2 */
  78         char    res3[4];        /* Reserved */
  79         uint    sdmatmp;        /* Internal */
  80 };
  81
  82 #define I2COM_START     0x80
  83 #define I2COM_MASTER    0x01
  84 #define I2CER_TXE       0x10
  85 #define I2CER_BUSY      0x04
  86 #define I2CER_TXB       0x02
  87 #define I2CER_RXB       0x01
  88 #define I2MOD_EN        0x01
  89
  90 /* I2C Registers */
  91 struct i2c_reg {
  92         u8      i2mod;
  93         u8      res1[3];
  94         u8      i2add;
  95         u8      res2[3];
  96         u8      i2brg;
  97         u8      res3[3];
  98         u8      i2com;
  99         u8      res4[3];
 100         u8      i2cer;
 101         u8      res5[3];
 102         u8      i2cmr;
 103 };
 104
 105 struct cpm_i2c {
 106         char *base;
 107         struct platform_device *ofdev;
 108         struct i2c_adapter adap;
 109         uint dp_addr;
 110         int version; /* CPM1=1, CPM2=2 */
 111         int irq;
 112         int cp_command;
 113         int freq;
 114         struct i2c_reg __iomem *i2c_reg;
 115         struct i2c_ram __iomem *i2c_ram;
 116         u16 i2c_addr;
 117         wait_queue_head_t i2c_wait;
 118         cbd_t __iomem *tbase;
 119         cbd_t __iomem *rbase;
 120         u_char *txbuf[CPM_MAXBD];
 121         u_char *rxbuf[CPM_MAXBD];
 122         dma_addr_t txdma[CPM_MAXBD];
 123         dma_addr_t rxdma[CPM_MAXBD];
 124 };
 125
 126 static irqreturn_t cpm_i2c_interrupt(int irq, void *dev_id)
 127 {
 128         struct cpm_i2c *cpm;
 129         struct i2c_reg __iomem *i2c_reg;
 130         struct i2c_adapter *adap = dev_id;
 131         int i;
 132
 133         cpm = i2c_get_adapdata(dev_id);
 134         i2c_reg = cpm->i2c_reg;
 135
 136         /* Clear interrupt. */
 137         i = in_8(&i2c_reg->i2cer);
 138         out_8(&i2c_reg->i2cer, i);
 139
 140         dev_dbg(&adap->dev, "Interrupt: %x\n", i);
 141
 142         wake_up(&cpm->i2c_wait);
 143
 144         return i ? IRQ_HANDLED : IRQ_NONE;
 145 }
 146
 147 static void cpm_reset_i2c_params(struct cpm_i2c *cpm)
 148 {
 149         struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
 150
 151         /* Set up the I2C parameters in the parameter ram. */
 152         out_be16(&i2c_ram->tbase, (u8 __iomem *)cpm->tbase - DPRAM_BASE);
 153         out_be16(&i2c_ram->rbase, (u8 __iomem *)cpm->rbase - DPRAM_BASE);
 154
 155         if (cpm->version == 1) {
 156                 out_8(&i2c_ram->tfcr, I2C_EB);
 157                 out_8(&i2c_ram->rfcr, I2C_EB);
 158         } else {
 159                 out_8(&i2c_ram->tfcr, I2C_EB_CPM2);
 160                 out_8(&i2c_ram->rfcr, I2C_EB_CPM2);
 161         }
 162
 163         out_be16(&i2c_ram->mrblr, CPM_MAX_READ);
 164
 165         out_be32(&i2c_ram->rstate, 0);
 166         out_be32(&i2c_ram->rdp, 0);
 167         out_be16(&i2c_ram->rbptr, 0);
 168         out_be16(&i2c_ram->rbc, 0);
 169         out_be32(&i2c_ram->rxtmp, 0);
 170         out_be32(&i2c_ram->tstate, 0);
 171         out_be32(&i2c_ram->tdp, 0);
 172         out_be16(&i2c_ram->tbptr, 0);
 173         out_be16(&i2c_ram->tbc, 0);
 174         out_be32(&i2c_ram->txtmp, 0);
 175 }
 176
 177 static void cpm_i2c_force_close(struct i2c_adapter *adap)
 178 {
 179         struct cpm_i2c *cpm = i2c_get_adapdata(adap);
 180         struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
 181
 182         dev_dbg(&adap->dev, "cpm_i2c_force_close()\n");
 183
 184         cpm_command(cpm->cp_command, CPM_CR_CLOSE_RX_BD);
 185
 186         out_8(&i2c_reg->i2cmr, 0x00);   /* Disable all interrupts */
 187         out_8(&i2c_reg->i2cer, 0xff);
 188 }
 189
 190 static void cpm_i2c_parse_message(struct i2c_adapter *adap,
 191         struct i2c_msg *pmsg, int num, int tx, int rx)
 192 {
 193         cbd_t __iomem *tbdf;
 194         cbd_t __iomem *rbdf;
 195         u_char addr;
 196         u_char *tb;
 197         u_char *rb;
 198         struct cpm_i2c *cpm = i2c_get_adapdata(adap);
 199
 200         tbdf = cpm->tbase + tx;
 201         rbdf = cpm->rbase + rx;
 202
 203         addr = pmsg->addr << 1;
 204         if (pmsg->flags & I2C_M_RD)
 205                 addr |= 1;
 206
 207         tb = cpm->txbuf[tx];
 208         rb = cpm->rxbuf[rx];
 209
 210         /* Align read buffer */
 211         rb = (u_char *) (((ulong) rb + 1) & ~1);
 212
 213         tb[0] = addr;           /* Device address byte w/rw flag */
 214
 215         out_be16(&tbdf->cbd_datlen, pmsg->len + 1);
 216         out_be16(&tbdf->cbd_sc, 0);
 217
 218         if (!(pmsg->flags & I2C_M_NOSTART))
 219                 setbits16(&tbdf->cbd_sc, BD_I2C_START);
 220
 221         if (tx + 1 == num)
 222                 setbits16(&tbdf->cbd_sc, BD_SC_LAST | BD_SC_WRAP);
 223
 224         if (pmsg->flags & I2C_M_RD) {
 225                 /*
 226                  * To read, we need an empty buffer of the proper length.
 227                  * All that is used is the first byte for address, the remainder
 228                  * is just used for timing (and doesn't really have to exist).
 229                  */
 230
 231                 dev_dbg(&adap->dev, "cpm_i2c_read(abyte=0x%x)\n", addr);
 232
 233                 out_be16(&rbdf->cbd_datlen, 0);
 234                 out_be16(&rbdf->cbd_sc, BD_SC_EMPTY | BD_SC_INTRPT);
 235
 236                 if (rx + 1 == CPM_MAXBD)
 237                         setbits16(&rbdf->cbd_sc, BD_SC_WRAP);
 238
 239                 eieio();
 240                 setbits16(&tbdf->cbd_sc, BD_SC_READY);
 241         } else {
 242                 dev_dbg(&adap->dev, "cpm_i2c_write(abyte=0x%x)\n", addr);
 243
 244                 memcpy(tb+1, pmsg->buf, pmsg->len);
 245
 246                 eieio();
 247                 setbits16(&tbdf->cbd_sc, BD_SC_READY | BD_SC_INTRPT);
 248         }
 249 }
 250
 251 static int cpm_i2c_check_message(struct i2c_adapter *adap,
 252         struct i2c_msg *pmsg, int tx, int rx)
 253 {
 254         cbd_t __iomem *tbdf;
 255         cbd_t __iomem *rbdf;
 256         u_char *tb;
 257         u_char *rb;
 258         struct cpm_i2c *cpm = i2c_get_adapdata(adap);
 259
 260         tbdf = cpm->tbase + tx;
 261         rbdf = cpm->rbase + rx;
 262
 263         tb = cpm->txbuf[tx];
 264         rb = cpm->rxbuf[rx];
 265
 266         /* Align read buffer */
 267         rb = (u_char *) (((uint) rb + 1) & ~1);
 268
 269         eieio();
 270         if (pmsg->flags & I2C_M_RD) {
 271                 dev_dbg(&adap->dev, "tx sc 0x%04x, rx sc 0x%04x\n",
 272                         in_be16(&tbdf->cbd_sc), in_be16(&rbdf->cbd_sc));
 273
 274                 if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
 275                         dev_dbg(&adap->dev, "I2C read; No ack\n");
 276                         return -ENXIO;
 277                 }
 278                 if (in_be16(&rbdf->cbd_sc) & BD_SC_EMPTY) {
 279                         dev_err(&adap->dev,
 280                                 "I2C read; complete but rbuf empty\n");
 281                         return -EREMOTEIO;
 282                 }
 283                 if (in_be16(&rbdf->cbd_sc) & BD_SC_OV) {
 284                         dev_err(&adap->dev, "I2C read; Overrun\n");
 285                         return -EREMOTEIO;
 286                 }
 287                 memcpy(pmsg->buf, rb, pmsg->len);
 288         } else {
 289                 dev_dbg(&adap->dev, "tx sc %d 0x%04x\n", tx,
 290                         in_be16(&tbdf->cbd_sc));
 291
 292                 if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
 293                         dev_dbg(&adap->dev, "I2C write; No ack\n");
 294                         return -ENXIO;
 295                 }
 296                 if (in_be16(&tbdf->cbd_sc) & BD_SC_UN) {
 297                         dev_err(&adap->dev, "I2C write; Underrun\n");
 298                         return -EIO;
 299                 }
 300                 if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
 301                         dev_err(&adap->dev, "I2C write; Collision\n");
 302                         return -EIO;
 303                 }
 304         }
 305         return 0;
 306 }
 307
 308 static int cpm_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 309 {
 310         struct cpm_i2c *cpm = i2c_get_adapdata(adap);
 311         struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
 312         struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
 313         struct i2c_msg *pmsg;
 314         int ret;
 315         int tptr;
 316         int rptr;
 317         cbd_t __iomem *tbdf;
 318         cbd_t __iomem *rbdf;
 319
 320         /* Reset to use first buffer */
 321         out_be16(&i2c_ram->rbptr, in_be16(&i2c_ram->rbase));
 322         out_be16(&i2c_ram->tbptr, in_be16(&i2c_ram->tbase));
 323
 324         tbdf = cpm->tbase;
 325         rbdf = cpm->rbase;
 326
 327         tptr = 0;
 328         rptr = 0;
 329
 330         /*
 331          * If there was a collision in the last i2c transaction,
 332          * Set I2COM_MASTER as it was cleared during collision.
 333          */
 334         if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
 335                 out_8(&cpm->i2c_reg->i2com, I2COM_MASTER);
 336         }
 337
 338         while (tptr < num) {
 339                 pmsg = &msgs[tptr];
 340                 dev_dbg(&adap->dev, "R: %d T: %d\n", rptr, tptr);
 341
 342                 cpm_i2c_parse_message(adap, pmsg, num, tptr, rptr);
 343                 if (pmsg->flags & I2C_M_RD)
 344                         rptr++;
 345                 tptr++;
 346         }
 347         /* Start transfer now */
 348         /* Enable RX/TX/Error interupts */
 349         out_8(&i2c_reg->i2cmr, I2CER_TXE | I2CER_TXB | I2CER_RXB);
 350         out_8(&i2c_reg->i2cer, 0xff);   /* Clear interrupt status */
 351         /* Chip bug, set enable here */
 352         setbits8(&i2c_reg->i2mod, I2MOD_EN);    /* Enable */
 353         /* Begin transmission */
 354         setbits8(&i2c_reg->i2com, I2COM_START);
 355
 356         tptr = 0;
 357         rptr = 0;
 358
 359         while (tptr < num) {
 360                 /* Check for outstanding messages */
 361                 dev_dbg(&adap->dev, "test ready.\n");
 362                 pmsg = &msgs[tptr];
 363                 if (pmsg->flags & I2C_M_RD)
 364                         ret = wait_event_timeout(cpm->i2c_wait,
 365                                 (in_be16(&tbdf[tptr].cbd_sc) & BD_SC_NAK) ||
 366                                 !(in_be16(&rbdf[rptr].cbd_sc) & BD_SC_EMPTY),
 367                                 1 * HZ);
 368                 else
 369                         ret = wait_event_timeout(cpm->i2c_wait,
 370                                 !(in_be16(&tbdf[tptr].cbd_sc) & BD_SC_READY),
 371                                 1 * HZ);
 372                 if (ret == 0) {
 373                         ret = -EREMOTEIO;
 374                         dev_err(&adap->dev, "I2C transfer: timeout\n");
 375                         goto out_err;
 376                 }
 377                 if (ret > 0) {
 378                         dev_dbg(&adap->dev, "ready.\n");
 379                         ret = cpm_i2c_check_message(adap, pmsg, tptr, rptr);
 380                         tptr++;
 381                         if (pmsg->flags & I2C_M_RD)
 382                                 rptr++;
 383                         if (ret)
 384                                 goto out_err;
 385                 }
 386         }
 387 #ifdef I2C_CHIP_ERRATA
 388         /*
 389          * Chip errata, clear enable. This is not needed on rev D4 CPUs.
 390          * Disabling I2C too early may cause too short stop condition
 391          */
 392         udelay(4);
 393         clrbits8(&i2c_reg->i2mod, I2MOD_EN);
 394 #endif
 395         return (num);
 396
 397 out_err:
 398         cpm_i2c_force_close(adap);
 399 #ifdef I2C_CHIP_ERRATA
 400         /*
 401          * Chip errata, clear enable. This is not needed on rev D4 CPUs.
 402          */
 403         clrbits8(&i2c_reg->i2mod, I2MOD_EN);
 404 #endif
 405         return ret;
 406 }
 407
 408 static u32 cpm_i2c_func(struct i2c_adapter *adap)
 409 {
 410         return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
 411 }
 412
 413 /* -----exported algorithm data: -------------------------------------  */
 414
 415 static const struct i2c_algorithm cpm_i2c_algo = {
 416         .master_xfer = cpm_i2c_xfer,
 417         .functionality = cpm_i2c_func,
 418 };
 419
 420 /* CPM_MAX_READ is also limiting writes according to the code! */
 421 static struct i2c_adapter_quirks cpm_i2c_quirks = {
 422         .max_num_msgs = CPM_MAXBD,
 423         .max_read_len = CPM_MAX_READ,
 424         .max_write_len = CPM_MAX_READ,
 425 };
 426
 427 static const struct i2c_adapter cpm_ops = {
 428         .owner          = THIS_MODULE,
 429         .name           = "i2c-cpm",
 430         .algo           = &cpm_i2c_algo,
 431         .quirks         = &cpm_i2c_quirks,
 432 };
 433
 434 static int cpm_i2c_setup(struct cpm_i2c *cpm)
 435 {
 436         struct platform_device *ofdev = cpm->ofdev;
 437         const u32 *data;
 438         int len, ret, i;
 439         void __iomem *i2c_base;
 440         cbd_t __iomem *tbdf;
 441         cbd_t __iomem *rbdf;
 442         unsigned char brg;
 443
 444         dev_dbg(&cpm->ofdev->dev, "cpm_i2c_setup()\n");
 445
 446         init_waitqueue_head(&cpm->i2c_wait);
 447
 448         cpm->irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
 449         if (!cpm->irq)
 450                 return -EINVAL;
 451
 452         /* Install interrupt handler. */
 453         ret = request_irq(cpm->irq, cpm_i2c_interrupt, 0, "cpm_i2c",
 454                           &cpm->adap);
 455         if (ret)
 456                 return ret;
 457
 458         /* I2C parameter RAM */
 459         i2c_base = of_iomap(ofdev->dev.of_node, 1);
 460         if (i2c_base == NULL) {
 461                 ret = -EINVAL;
 462                 goto out_irq;
 463         }
 464
 465         if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm1-i2c")) {
 466
 467                 /* Check for and use a microcode relocation patch. */
 468                 cpm->i2c_ram = i2c_base;
 469                 cpm->i2c_addr = in_be16(&cpm->i2c_ram->rpbase);
 470
 471                 /*
 472                  * Maybe should use cpm_muram_alloc instead of hardcoding
 473                  * this in micropatch.c
 474                  */
 475                 if (cpm->i2c_addr) {
 476                         cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
 477                         iounmap(i2c_base);
 478                 }
 479
 480                 cpm->version = 1;
 481
 482         } else if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm2-i2c")) {
 483                 cpm->i2c_addr = cpm_muram_alloc(sizeof(struct i2c_ram), 64);
 484                 cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
 485                 out_be16(i2c_base, cpm->i2c_addr);
 486                 iounmap(i2c_base);
 487
 488                 cpm->version = 2;
 489
 490         } else {
 491                 iounmap(i2c_base);
 492                 ret = -EINVAL;
 493                 goto out_irq;
 494         }
 495
 496         /* I2C control/status registers */
 497         cpm->i2c_reg = of_iomap(ofdev->dev.of_node, 0);
 498         if (cpm->i2c_reg == NULL) {
 499                 ret = -EINVAL;
 500                 goto out_ram;
 501         }
 502
 503         data = of_get_property(ofdev->dev.of_node, "fsl,cpm-command", &len);
 504         if (!data || len != 4) {
 505                 ret = -EINVAL;
 506                 goto out_reg;
 507         }
 508         cpm->cp_command = *data;
 509
 510         data = of_get_property(ofdev->dev.of_node, "linux,i2c-class", &len);
 511         if (data && len == 4)
 512                 cpm->adap.class = *data;
 513
 514         data = of_get_property(ofdev->dev.of_node, "clock-frequency", &len);
 515         if (data && len == 4)
 516                 cpm->freq = *data;
 517         else
 518                 cpm->freq = 60000; /* use 60kHz i2c clock by default */
 519
 520         /*
 521          * Allocate space for CPM_MAXBD transmit and receive buffer
 522          * descriptors in the DP ram.
 523          */
 524         cpm->dp_addr = cpm_muram_alloc(sizeof(cbd_t) * 2 * CPM_MAXBD, 8);
 525         if (!cpm->dp_addr) {
 526                 ret = -ENOMEM;
 527                 goto out_reg;
 528         }
 529
 530         cpm->tbase = cpm_muram_addr(cpm->dp_addr);
 531         cpm->rbase = cpm_muram_addr(cpm->dp_addr + sizeof(cbd_t) * CPM_MAXBD);
 532
 533         /* Allocate TX and RX buffers */
 534
 535         tbdf = cpm->tbase;
 536         rbdf = cpm->rbase;
 537
 538         for (i = 0; i < CPM_MAXBD; i++) {
 539                 cpm->rxbuf[i] = dma_alloc_coherent(&cpm->ofdev->dev,
 540                                                    CPM_MAX_READ + 1,
 541                                                    &cpm->rxdma[i], GFP_KERNEL);
 542                 if (!cpm->rxbuf[i]) {
 543                         ret = -ENOMEM;
 544                         goto out_muram;
 545                 }
 546                 out_be32(&rbdf[i].cbd_bufaddr, ((cpm->rxdma[i] + 1) & ~1));
 547
 548                 cpm->txbuf[i] = (unsigned char *)dma_alloc_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1, &cpm->txdma[i], GFP_KERNEL);
 549                 if (!cpm->txbuf[i]) {
 550                         ret = -ENOMEM;
 551                         goto out_muram;
 552                 }
 553                 out_be32(&tbdf[i].cbd_bufaddr, cpm->txdma[i]);
 554         }
 555
 556         /* Initialize Tx/Rx parameters. */
 557
 558         cpm_reset_i2c_params(cpm);
 559
 560         dev_dbg(&cpm->ofdev->dev, "i2c_ram 0x%p, i2c_addr 0x%04x, freq %d\n",
 561                 cpm->i2c_ram, cpm->i2c_addr, cpm->freq);
 562         dev_dbg(&cpm->ofdev->dev, "tbase 0x%04x, rbase 0x%04x\n",
 563                 (u8 __iomem *)cpm->tbase - DPRAM_BASE,
 564                 (u8 __iomem *)cpm->rbase - DPRAM_BASE);
 565
 566         cpm_command(cpm->cp_command, CPM_CR_INIT_TRX);
 567
 568         /*
 569          * Select an invalid address. Just make sure we don't use loopback mode
 570          */
 571         out_8(&cpm->i2c_reg->i2add, 0x7f << 1);
 572
 573         /*
 574          * PDIV is set to 00 in i2mod, so brgclk/32 is used as input to the
 575          * i2c baud rate generator. This is divided by 2 x (DIV + 3) to get
 576          * the actual i2c bus frequency.
 577          */
 578         brg = get_brgfreq() / (32 * 2 * cpm->freq) - 3;
 579         out_8(&cpm->i2c_reg->i2brg, brg);
 580
 581         out_8(&cpm->i2c_reg->i2mod, 0x00);
 582         out_8(&cpm->i2c_reg->i2com, I2COM_MASTER);      /* Master mode */
 583
 584         /* Disable interrupts. */
 585         out_8(&cpm->i2c_reg->i2cmr, 0);
 586         out_8(&cpm->i2c_reg->i2cer, 0xff);
 587
 588         return 0;
 589
 590 out_muram:
 591         for (i = 0; i < CPM_MAXBD; i++) {
 592                 if (cpm->rxbuf[i])
 593                         dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
 594                                 cpm->rxbuf[i], cpm->rxdma[i]);
 595                 if (cpm->txbuf[i])
 596                         dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
 597                                 cpm->txbuf[i], cpm->txdma[i]);
 598         }
 599         cpm_muram_free(cpm->dp_addr);
 600 out_reg:
 601         iounmap(cpm->i2c_reg);
 602 out_ram:
 603         if ((cpm->version == 1) && (!cpm->i2c_addr))
 604                 iounmap(cpm->i2c_ram);
 605         if (cpm->version == 2)
 606                 cpm_muram_free(cpm->i2c_addr);
 607 out_irq:
 608         free_irq(cpm->irq, &cpm->adap);
 609         return ret;
 610 }
 611
 612 static void cpm_i2c_shutdown(struct cpm_i2c *cpm)
 613 {
 614         int i;
 615
 616         /* Shut down I2C. */
 617         clrbits8(&cpm->i2c_reg->i2mod, I2MOD_EN);
 618
 619         /* Disable interrupts */
 620         out_8(&cpm->i2c_reg->i2cmr, 0);
 621         out_8(&cpm->i2c_reg->i2cer, 0xff);
 622
 623         free_irq(cpm->irq, &cpm->adap);
 624
 625         /* Free all memory */
 626         for (i = 0; i < CPM_MAXBD; i++) {
 627                 dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
 628                         cpm->rxbuf[i], cpm->rxdma[i]);
 629                 dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
 630                         cpm->txbuf[i], cpm->txdma[i]);
 631         }
 632
 633         cpm_muram_free(cpm->dp_addr);
 634         iounmap(cpm->i2c_reg);
 635
 636         if ((cpm->version == 1) && (!cpm->i2c_addr))
 637                 iounmap(cpm->i2c_ram);
 638         if (cpm->version == 2)
 639                 cpm_muram_free(cpm->i2c_addr);
 640 }
 641
 642 static int cpm_i2c_probe(struct platform_device *ofdev)
 643 {
 644         int result, len;
 645         struct cpm_i2c *cpm;
 646         const u32 *data;
 647
 648         cpm = kzalloc(sizeof(struct cpm_i2c), GFP_KERNEL);
 649         if (!cpm)
 650                 return -ENOMEM;
 651
 652         cpm->ofdev = ofdev;
 653
 654         platform_set_drvdata(ofdev, cpm);
 655
 656         cpm->adap = cpm_ops;
 657         i2c_set_adapdata(&cpm->adap, cpm);
 658         cpm->adap.dev.parent = &ofdev->dev;
 659         cpm->adap.dev.of_node = of_node_get(ofdev->dev.of_node);
 660
 661         result = cpm_i2c_setup(cpm);
 662         if (result) {
 663                 dev_err(&ofdev->dev, "Unable to init hardware\n");
 664                 goto out_free;
 665         }
 666
 667         /* register new adapter to i2c module... */
 668
 669         data = of_get_property(ofdev->dev.of_node, "linux,i2c-index", &len);
 670         cpm->adap.nr = (data && len == 4) ? be32_to_cpup(data) : -1;
 671         result = i2c_add_numbered_adapter(&cpm->adap);
 672
 673         if (result < 0) {
 674                 dev_err(&ofdev->dev, "Unable to register with I2C\n");
 675                 goto out_shut;
 676         }
 677
 678         dev_dbg(&ofdev->dev, "hw routines for %s registered.\n",
 679                 cpm->adap.name);
 680
 681         return 0;
 682 out_shut:
 683         cpm_i2c_shutdown(cpm);
 684 out_free:
 685         kfree(cpm);
 686
 687         return result;
 688 }
 689
 690 static int cpm_i2c_remove(struct platform_device *ofdev)
 691 {
 692         struct cpm_i2c *cpm = platform_get_drvdata(ofdev);
 693
 694         i2c_del_adapter(&cpm->adap);
 695
 696         cpm_i2c_shutdown(cpm);
 697
 698         kfree(cpm);
 699
 700         return 0;
 701 }
 702
 703 static const struct of_device_id cpm_i2c_match[] = {
 704         {
 705                 .compatible = "fsl,cpm1-i2c",
 706         },
 707         {
 708                 .compatible = "fsl,cpm2-i2c",
 709         },
 710         {},
 711 };
 712
 713 MODULE_DEVICE_TABLE(of, cpm_i2c_match);
 714
 715 static struct platform_driver cpm_i2c_driver = {
 716         .probe          = cpm_i2c_probe,
 717         .remove         = cpm_i2c_remove,
 718         .driver = {
 719                 .name = "fsl-i2c-cpm",
 720                 .of_match_table = cpm_i2c_match,
 721         },
 722 };
 723
 724 module_platform_driver(cpm_i2c_driver);
 725
 726 MODULE_AUTHOR("Jochen Friedrich <jochen@scram.de>");
 727 MODULE_DESCRIPTION("I2C-Bus adapter routines for CPM boards");
 728 MODULE_LICENSE("GPL");