linux/drivers/i2c/busses/i2c-cpm.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Freescale CPM1/CPM2 I2C interface.
   4 * Copyright (c) 1999 Dan Malek (dmalek@jlc.net).
   5 *
   6 * moved into proper i2c interface;
   7 * Brad Parker (brad@heeltoe.com)
   8 *
   9 * Parts from dbox2_i2c.c (cvs.tuxbox.org)
  10 * (C) 2000-2001 Felix Domke (tmbinc@gmx.net), Gillem (htoa@gmx.net)
  11 *
  12 * (C) 2007 Montavista Software, Inc.
  13 * Vitaly Bordug <vitb@kernel.crashing.org>
  14 *
  15 * Converted to of_platform_device. Renamed to i2c-cpm.c.
  16 * (C) 2007,2008 Jochen Friedrich <jochen@scram.de>
  17 */
  18
  19#include <linux/kernel.h>
  20#include <linux/module.h>
  21#include <linux/delay.h>
  22#include <linux/slab.h>
  23#include <linux/interrupt.h>
  24#include <linux/errno.h>
  25#include <linux/stddef.h>
  26#include <linux/i2c.h>
  27#include <linux/io.h>
  28#include <linux/dma-mapping.h>
  29#include <linux/of_address.h>
  30#include <linux/of_device.h>
  31#include <linux/of_irq.h>
  32#include <linux/of_platform.h>
  33#include <sysdev/fsl_soc.h>
  34#include <asm/cpm.h>
  35
  36/* Try to define this if you have an older CPU (earlier than rev D4) */
  37/* However, better use a GPIO based bitbang driver in this case :/   */
  38#undef  I2C_CHIP_ERRATA
  39
  40#define CPM_MAX_READ    513
  41#define CPM_MAXBD       4
  42
  43#define I2C_EB                  (0x10) /* Big endian mode */
  44#define I2C_EB_CPM2             (0x30) /* Big endian mode, memory snoop */
  45
  46#define DPRAM_BASE              ((u8 __iomem __force *)cpm_muram_addr(0))
  47
  48/* I2C parameter RAM. */
  49struct i2c_ram {
  50        ushort  rbase;          /* Rx Buffer descriptor base address */
  51        ushort  tbase;          /* Tx Buffer descriptor base address */
  52        u_char  rfcr;           /* Rx function code */
  53        u_char  tfcr;           /* Tx function code */
  54        ushort  mrblr;          /* Max receive buffer length */
  55        uint    rstate;         /* Internal */
  56        uint    rdp;            /* Internal */
  57        ushort  rbptr;          /* Rx Buffer descriptor pointer */
  58        ushort  rbc;            /* Internal */
  59        uint    rxtmp;          /* Internal */
  60        uint    tstate;         /* Internal */
  61        uint    tdp;            /* Internal */
  62        ushort  tbptr;          /* Tx Buffer descriptor pointer */
  63        ushort  tbc;            /* Internal */
  64        uint    txtmp;          /* Internal */
  65        char    res1[4];        /* Reserved */
  66        ushort  rpbase;         /* Relocation pointer */
  67        char    res2[2];        /* Reserved */
  68};
  69
  70#define I2COM_START     0x80
  71#define I2COM_MASTER    0x01
  72#define I2CER_TXE       0x10
  73#define I2CER_BUSY      0x04
  74#define I2CER_TXB       0x02
  75#define I2CER_RXB       0x01
  76#define I2MOD_EN        0x01
  77
  78/* I2C Registers */
  79struct i2c_reg {
  80        u8      i2mod;
  81        u8      res1[3];
  82        u8      i2add;
  83        u8      res2[3];
  84        u8      i2brg;
  85        u8      res3[3];
  86        u8      i2com;
  87        u8      res4[3];
  88        u8      i2cer;
  89        u8      res5[3];
  90        u8      i2cmr;
  91};
  92
  93struct cpm_i2c {
  94        char *base;
  95        struct platform_device *ofdev;
  96        struct i2c_adapter adap;
  97        uint dp_addr;
  98        int version; /* CPM1=1, CPM2=2 */
  99        int irq;
 100        int cp_command;
 101        int freq;
 102        struct i2c_reg __iomem *i2c_reg;
 103        struct i2c_ram __iomem *i2c_ram;
 104        u16 i2c_addr;
 105        wait_queue_head_t i2c_wait;
 106        cbd_t __iomem *tbase;
 107        cbd_t __iomem *rbase;
 108        u_char *txbuf[CPM_MAXBD];
 109        u_char *rxbuf[CPM_MAXBD];
 110        dma_addr_t txdma[CPM_MAXBD];
 111        dma_addr_t rxdma[CPM_MAXBD];
 112};
 113
 114static irqreturn_t cpm_i2c_interrupt(int irq, void *dev_id)
 115{
 116        struct cpm_i2c *cpm;
 117        struct i2c_reg __iomem *i2c_reg;
 118        struct i2c_adapter *adap = dev_id;
 119        int i;
 120
 121        cpm = i2c_get_adapdata(dev_id);
 122        i2c_reg = cpm->i2c_reg;
 123
 124        /* Clear interrupt. */
 125        i = in_8(&i2c_reg->i2cer);
 126        out_8(&i2c_reg->i2cer, i);
 127
 128        dev_dbg(&adap->dev, "Interrupt: %x\n", i);
 129
 130        wake_up(&cpm->i2c_wait);
 131
 132        return i ? IRQ_HANDLED : IRQ_NONE;
 133}
 134
 135static void cpm_reset_i2c_params(struct cpm_i2c *cpm)
 136{
 137        struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
 138
 139        /* Set up the I2C parameters in the parameter ram. */
 140        out_be16(&i2c_ram->tbase, (u8 __iomem *)cpm->tbase - DPRAM_BASE);
 141        out_be16(&i2c_ram->rbase, (u8 __iomem *)cpm->rbase - DPRAM_BASE);
 142
 143        if (cpm->version == 1) {
 144                out_8(&i2c_ram->tfcr, I2C_EB);
 145                out_8(&i2c_ram->rfcr, I2C_EB);
 146        } else {
 147                out_8(&i2c_ram->tfcr, I2C_EB_CPM2);
 148                out_8(&i2c_ram->rfcr, I2C_EB_CPM2);
 149        }
 150
 151        out_be16(&i2c_ram->mrblr, CPM_MAX_READ);
 152
 153        out_be32(&i2c_ram->rstate, 0);
 154        out_be32(&i2c_ram->rdp, 0);
 155        out_be16(&i2c_ram->rbptr, 0);
 156        out_be16(&i2c_ram->rbc, 0);
 157        out_be32(&i2c_ram->rxtmp, 0);
 158        out_be32(&i2c_ram->tstate, 0);
 159        out_be32(&i2c_ram->tdp, 0);
 160        out_be16(&i2c_ram->tbptr, 0);
 161        out_be16(&i2c_ram->tbc, 0);
 162        out_be32(&i2c_ram->txtmp, 0);
 163}
 164
 165static void cpm_i2c_force_close(struct i2c_adapter *adap)
 166{
 167        struct cpm_i2c *cpm = i2c_get_adapdata(adap);
 168        struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
 169
 170        dev_dbg(&adap->dev, "cpm_i2c_force_close()\n");
 171
 172        cpm_command(cpm->cp_command, CPM_CR_CLOSE_RX_BD);
 173
 174        out_8(&i2c_reg->i2cmr, 0x00);   /* Disable all interrupts */
 175        out_8(&i2c_reg->i2cer, 0xff);
 176}
 177
 178static void cpm_i2c_parse_message(struct i2c_adapter *adap,
 179        struct i2c_msg *pmsg, int num, int tx, int rx)
 180{
 181        cbd_t __iomem *tbdf;
 182        cbd_t __iomem *rbdf;
 183        u_char addr;
 184        u_char *tb;
 185        u_char *rb;
 186        struct cpm_i2c *cpm = i2c_get_adapdata(adap);
 187
 188        tbdf = cpm->tbase + tx;
 189        rbdf = cpm->rbase + rx;
 190
 191        addr = i2c_8bit_addr_from_msg(pmsg);
 192
 193        tb = cpm->txbuf[tx];
 194        rb = cpm->rxbuf[rx];
 195
 196        /* Align read buffer */
 197        rb = (u_char *) (((ulong) rb + 1) & ~1);
 198
 199        tb[0] = addr;           /* Device address byte w/rw flag */
 200
 201        out_be16(&tbdf->cbd_datlen, pmsg->len + 1);
 202        out_be16(&tbdf->cbd_sc, 0);
 203
 204        if (!(pmsg->flags & I2C_M_NOSTART))
 205                setbits16(&tbdf->cbd_sc, BD_I2C_START);
 206
 207        if (tx + 1 == num)
 208                setbits16(&tbdf->cbd_sc, BD_SC_LAST | BD_SC_WRAP);
 209
 210        if (pmsg->flags & I2C_M_RD) {
 211                /*
 212                 * To read, we need an empty buffer of the proper length.
 213                 * All that is used is the first byte for address, the remainder
 214                 * is just used for timing (and doesn't really have to exist).
 215                 */
 216
 217                dev_dbg(&adap->dev, "cpm_i2c_read(abyte=0x%x)\n", addr);
 218
 219                out_be16(&rbdf->cbd_datlen, 0);
 220                out_be16(&rbdf->cbd_sc, BD_SC_EMPTY | BD_SC_INTRPT);
 221
 222                if (rx + 1 == CPM_MAXBD)
 223                        setbits16(&rbdf->cbd_sc, BD_SC_WRAP);
 224
 225                eieio();
 226                setbits16(&tbdf->cbd_sc, BD_SC_READY);
 227        } else {
 228                dev_dbg(&adap->dev, "cpm_i2c_write(abyte=0x%x)\n", addr);
 229
 230                memcpy(tb+1, pmsg->buf, pmsg->len);
 231
 232                eieio();
 233                setbits16(&tbdf->cbd_sc, BD_SC_READY | BD_SC_INTRPT);
 234        }
 235}
 236
 237static int cpm_i2c_check_message(struct i2c_adapter *adap,
 238        struct i2c_msg *pmsg, int tx, int rx)
 239{
 240        cbd_t __iomem *tbdf;
 241        cbd_t __iomem *rbdf;
 242        u_char *tb;
 243        u_char *rb;
 244        struct cpm_i2c *cpm = i2c_get_adapdata(adap);
 245
 246        tbdf = cpm->tbase + tx;
 247        rbdf = cpm->rbase + rx;
 248
 249        tb = cpm->txbuf[tx];
 250        rb = cpm->rxbuf[rx];
 251
 252        /* Align read buffer */
 253        rb = (u_char *) (((uint) rb + 1) & ~1);
 254
 255        eieio();
 256        if (pmsg->flags & I2C_M_RD) {
 257                dev_dbg(&adap->dev, "tx sc 0x%04x, rx sc 0x%04x\n",
 258                        in_be16(&tbdf->cbd_sc), in_be16(&rbdf->cbd_sc));
 259
 260                if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
 261                        dev_dbg(&adap->dev, "I2C read; No ack\n");
 262                        return -ENXIO;
 263                }
 264                if (in_be16(&rbdf->cbd_sc) & BD_SC_EMPTY) {
 265                        dev_err(&adap->dev,
 266                                "I2C read; complete but rbuf empty\n");
 267                        return -EREMOTEIO;
 268                }
 269                if (in_be16(&rbdf->cbd_sc) & BD_SC_OV) {
 270                        dev_err(&adap->dev, "I2C read; Overrun\n");
 271                        return -EREMOTEIO;
 272                }
 273                memcpy(pmsg->buf, rb, pmsg->len);
 274        } else {
 275                dev_dbg(&adap->dev, "tx sc %d 0x%04x\n", tx,
 276                        in_be16(&tbdf->cbd_sc));
 277
 278                if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
 279                        dev_dbg(&adap->dev, "I2C write; No ack\n");
 280                        return -ENXIO;
 281                }
 282                if (in_be16(&tbdf->cbd_sc) & BD_SC_UN) {
 283                        dev_err(&adap->dev, "I2C write; Underrun\n");
 284                        return -EIO;
 285                }
 286                if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
 287                        dev_err(&adap->dev, "I2C write; Collision\n");
 288                        return -EIO;
 289                }
 290        }
 291        return 0;
 292}
 293
 294static int cpm_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 295{
 296        struct cpm_i2c *cpm = i2c_get_adapdata(adap);
 297        struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
 298        struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
 299        struct i2c_msg *pmsg;
 300        int ret;
 301        int tptr;
 302        int rptr;
 303        cbd_t __iomem *tbdf;
 304        cbd_t __iomem *rbdf;
 305
 306        /* Reset to use first buffer */
 307        out_be16(&i2c_ram->rbptr, in_be16(&i2c_ram->rbase));
 308        out_be16(&i2c_ram->tbptr, in_be16(&i2c_ram->tbase));
 309
 310        tbdf = cpm->tbase;
 311        rbdf = cpm->rbase;
 312
 313        tptr = 0;
 314        rptr = 0;
 315
 316        /*
 317         * If there was a collision in the last i2c transaction,
 318         * Set I2COM_MASTER as it was cleared during collision.
 319         */
 320        if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
 321                out_8(&cpm->i2c_reg->i2com, I2COM_MASTER);
 322        }
 323
 324        while (tptr < num) {
 325                pmsg = &msgs[tptr];
 326                dev_dbg(&adap->dev, "R: %d T: %d\n", rptr, tptr);
 327
 328                cpm_i2c_parse_message(adap, pmsg, num, tptr, rptr);
 329                if (pmsg->flags & I2C_M_RD)
 330                        rptr++;
 331                tptr++;
 332        }
 333        /* Start transfer now */
 334        /* Enable RX/TX/Error interupts */
 335        out_8(&i2c_reg->i2cmr, I2CER_TXE | I2CER_TXB | I2CER_RXB);
 336        out_8(&i2c_reg->i2cer, 0xff);   /* Clear interrupt status */
 337        /* Chip bug, set enable here */
 338        setbits8(&i2c_reg->i2mod, I2MOD_EN);    /* Enable */
 339        /* Begin transmission */
 340        setbits8(&i2c_reg->i2com, I2COM_START);
 341
 342        tptr = 0;
 343        rptr = 0;
 344
 345        while (tptr < num) {
 346                /* Check for outstanding messages */
 347                dev_dbg(&adap->dev, "test ready.\n");
 348                pmsg = &msgs[tptr];
 349                if (pmsg->flags & I2C_M_RD)
 350                        ret = wait_event_timeout(cpm->i2c_wait,
 351                                (in_be16(&tbdf[tptr].cbd_sc) & BD_SC_NAK) ||
 352                                !(in_be16(&rbdf[rptr].cbd_sc) & BD_SC_EMPTY),
 353                                1 * HZ);
 354                else
 355                        ret = wait_event_timeout(cpm->i2c_wait,
 356                                !(in_be16(&tbdf[tptr].cbd_sc) & BD_SC_READY),
 357                                1 * HZ);
 358                if (ret == 0) {
 359                        ret = -EREMOTEIO;
 360                        dev_err(&adap->dev, "I2C transfer: timeout\n");
 361                        goto out_err;
 362                }
 363                if (ret > 0) {
 364                        dev_dbg(&adap->dev, "ready.\n");
 365                        ret = cpm_i2c_check_message(adap, pmsg, tptr, rptr);
 366                        tptr++;
 367                        if (pmsg->flags & I2C_M_RD)
 368                                rptr++;
 369                        if (ret)
 370                                goto out_err;
 371                }
 372        }
 373#ifdef I2C_CHIP_ERRATA
 374        /*
 375         * Chip errata, clear enable. This is not needed on rev D4 CPUs.
 376         * Disabling I2C too early may cause too short stop condition
 377         */
 378        udelay(4);
 379        clrbits8(&i2c_reg->i2mod, I2MOD_EN);
 380#endif
 381        return (num);
 382
 383out_err:
 384        cpm_i2c_force_close(adap);
 385#ifdef I2C_CHIP_ERRATA
 386        /*
 387         * Chip errata, clear enable. This is not needed on rev D4 CPUs.
 388         */
 389        clrbits8(&i2c_reg->i2mod, I2MOD_EN);
 390#endif
 391        return ret;
 392}
 393
 394static u32 cpm_i2c_func(struct i2c_adapter *adap)
 395{
 396        return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
 397}
 398
 399/* -----exported algorithm data: -------------------------------------  */
 400
 401static const struct i2c_algorithm cpm_i2c_algo = {
 402        .master_xfer = cpm_i2c_xfer,
 403        .functionality = cpm_i2c_func,
 404};
 405
 406/* CPM_MAX_READ is also limiting writes according to the code! */
 407static const struct i2c_adapter_quirks cpm_i2c_quirks = {
 408        .max_num_msgs = CPM_MAXBD,
 409        .max_read_len = CPM_MAX_READ,
 410        .max_write_len = CPM_MAX_READ,
 411};
 412
 413static const struct i2c_adapter cpm_ops = {
 414        .owner          = THIS_MODULE,
 415        .name           = "i2c-cpm",
 416        .algo           = &cpm_i2c_algo,
 417        .quirks         = &cpm_i2c_quirks,
 418};
 419
 420static int cpm_i2c_setup(struct cpm_i2c *cpm)
 421{
 422        struct platform_device *ofdev = cpm->ofdev;
 423        const u32 *data;
 424        int len, ret, i;
 425        void __iomem *i2c_base;
 426        cbd_t __iomem *tbdf;
 427        cbd_t __iomem *rbdf;
 428        unsigned char brg;
 429
 430        dev_dbg(&cpm->ofdev->dev, "cpm_i2c_setup()\n");
 431
 432        init_waitqueue_head(&cpm->i2c_wait);
 433
 434        cpm->irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
 435        if (!cpm->irq)
 436                return -EINVAL;
 437
 438        /* Install interrupt handler. */
 439        ret = request_irq(cpm->irq, cpm_i2c_interrupt, 0, "cpm_i2c",
 440                          &cpm->adap);
 441        if (ret)
 442                return ret;
 443
 444        /* I2C parameter RAM */
 445        i2c_base = of_iomap(ofdev->dev.of_node, 1);
 446        if (i2c_base == NULL) {
 447                ret = -EINVAL;
 448                goto out_irq;
 449        }
 450
 451        if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm1-i2c")) {
 452
 453                /* Check for and use a microcode relocation patch. */
 454                cpm->i2c_ram = i2c_base;
 455                cpm->i2c_addr = in_be16(&cpm->i2c_ram->rpbase);
 456
 457                /*
 458                 * Maybe should use cpm_muram_alloc instead of hardcoding
 459                 * this in micropatch.c
 460                 */
 461                if (cpm->i2c_addr) {
 462                        cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
 463                        iounmap(i2c_base);
 464                }
 465
 466                cpm->version = 1;
 467
 468        } else if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm2-i2c")) {
 469                cpm->i2c_addr = cpm_muram_alloc(sizeof(struct i2c_ram), 64);
 470                cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
 471                out_be16(i2c_base, cpm->i2c_addr);
 472                iounmap(i2c_base);
 473
 474                cpm->version = 2;
 475
 476        } else {
 477                iounmap(i2c_base);
 478                ret = -EINVAL;
 479                goto out_irq;
 480        }
 481
 482        /* I2C control/status registers */
 483        cpm->i2c_reg = of_iomap(ofdev->dev.of_node, 0);
 484        if (cpm->i2c_reg == NULL) {
 485                ret = -EINVAL;
 486                goto out_ram;
 487        }
 488
 489        data = of_get_property(ofdev->dev.of_node, "fsl,cpm-command", &len);
 490        if (!data || len != 4) {
 491                ret = -EINVAL;
 492                goto out_reg;
 493        }
 494        cpm->cp_command = *data;
 495
 496        data = of_get_property(ofdev->dev.of_node, "linux,i2c-class", &len);
 497        if (data && len == 4)
 498                cpm->adap.class = *data;
 499
 500        data = of_get_property(ofdev->dev.of_node, "clock-frequency", &len);
 501        if (data && len == 4)
 502                cpm->freq = *data;
 503        else
 504                cpm->freq = 60000; /* use 60kHz i2c clock by default */
 505
 506        /*
 507         * Allocate space for CPM_MAXBD transmit and receive buffer
 508         * descriptors in the DP ram.
 509         */
 510        cpm->dp_addr = cpm_muram_alloc(sizeof(cbd_t) * 2 * CPM_MAXBD, 8);
 511        if (!cpm->dp_addr) {
 512                ret = -ENOMEM;
 513                goto out_reg;
 514        }
 515
 516        cpm->tbase = cpm_muram_addr(cpm->dp_addr);
 517        cpm->rbase = cpm_muram_addr(cpm->dp_addr + sizeof(cbd_t) * CPM_MAXBD);
 518
 519        /* Allocate TX and RX buffers */
 520
 521        tbdf = cpm->tbase;
 522        rbdf = cpm->rbase;
 523
 524        for (i = 0; i < CPM_MAXBD; i++) {
 525                cpm->rxbuf[i] = dma_alloc_coherent(&cpm->ofdev->dev,
 526                                                   CPM_MAX_READ + 1,
 527                                                   &cpm->rxdma[i], GFP_KERNEL);
 528                if (!cpm->rxbuf[i]) {
 529                        ret = -ENOMEM;
 530                        goto out_muram;
 531                }
 532                out_be32(&rbdf[i].cbd_bufaddr, ((cpm->rxdma[i] + 1) & ~1));
 533
 534                cpm->txbuf[i] = dma_alloc_coherent(&cpm->ofdev->dev,
 535                                                   CPM_MAX_READ + 1,
 536                                                   &cpm->txdma[i], GFP_KERNEL);
 537                if (!cpm->txbuf[i]) {
 538                        ret = -ENOMEM;
 539                        goto out_muram;
 540                }
 541                out_be32(&tbdf[i].cbd_bufaddr, cpm->txdma[i]);
 542        }
 543
 544        /* Initialize Tx/Rx parameters. */
 545
 546        cpm_reset_i2c_params(cpm);
 547
 548        dev_dbg(&cpm->ofdev->dev, "i2c_ram 0x%p, i2c_addr 0x%04x, freq %d\n",
 549                cpm->i2c_ram, cpm->i2c_addr, cpm->freq);
 550        dev_dbg(&cpm->ofdev->dev, "tbase 0x%04x, rbase 0x%04x\n",
 551                (u8 __iomem *)cpm->tbase - DPRAM_BASE,
 552                (u8 __iomem *)cpm->rbase - DPRAM_BASE);
 553
 554        cpm_command(cpm->cp_command, CPM_CR_INIT_TRX);
 555
 556        /*
 557         * Select an invalid address. Just make sure we don't use loopback mode
 558         */
 559        out_8(&cpm->i2c_reg->i2add, 0x7f << 1);
 560
 561        /*
 562         * PDIV is set to 00 in i2mod, so brgclk/32 is used as input to the
 563         * i2c baud rate generator. This is divided by 2 x (DIV + 3) to get
 564         * the actual i2c bus frequency.
 565         */
 566        brg = get_brgfreq() / (32 * 2 * cpm->freq) - 3;
 567        out_8(&cpm->i2c_reg->i2brg, brg);
 568
 569        out_8(&cpm->i2c_reg->i2mod, 0x00);
 570        out_8(&cpm->i2c_reg->i2com, I2COM_MASTER);      /* Master mode */
 571
 572        /* Disable interrupts. */
 573        out_8(&cpm->i2c_reg->i2cmr, 0);
 574        out_8(&cpm->i2c_reg->i2cer, 0xff);
 575
 576        return 0;
 577
 578out_muram:
 579        for (i = 0; i < CPM_MAXBD; i++) {
 580                if (cpm->rxbuf[i])
 581                        dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
 582                                cpm->rxbuf[i], cpm->rxdma[i]);
 583                if (cpm->txbuf[i])
 584                        dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
 585                                cpm->txbuf[i], cpm->txdma[i]);
 586        }
 587        cpm_muram_free(cpm->dp_addr);
 588out_reg:
 589        iounmap(cpm->i2c_reg);
 590out_ram:
 591        if ((cpm->version == 1) && (!cpm->i2c_addr))
 592                iounmap(cpm->i2c_ram);
 593        if (cpm->version == 2)
 594                cpm_muram_free(cpm->i2c_addr);
 595out_irq:
 596        free_irq(cpm->irq, &cpm->adap);
 597        return ret;
 598}
 599
 600static void cpm_i2c_shutdown(struct cpm_i2c *cpm)
 601{
 602        int i;
 603
 604        /* Shut down I2C. */
 605        clrbits8(&cpm->i2c_reg->i2mod, I2MOD_EN);
 606
 607        /* Disable interrupts */
 608        out_8(&cpm->i2c_reg->i2cmr, 0);
 609        out_8(&cpm->i2c_reg->i2cer, 0xff);
 610
 611        free_irq(cpm->irq, &cpm->adap);
 612
 613        /* Free all memory */
 614        for (i = 0; i < CPM_MAXBD; i++) {
 615                dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
 616                        cpm->rxbuf[i], cpm->rxdma[i]);
 617                dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
 618                        cpm->txbuf[i], cpm->txdma[i]);
 619        }
 620
 621        cpm_muram_free(cpm->dp_addr);
 622        iounmap(cpm->i2c_reg);
 623
 624        if ((cpm->version == 1) && (!cpm->i2c_addr))
 625                iounmap(cpm->i2c_ram);
 626        if (cpm->version == 2)
 627                cpm_muram_free(cpm->i2c_addr);
 628}
 629
 630static int cpm_i2c_probe(struct platform_device *ofdev)
 631{
 632        int result, len;
 633        struct cpm_i2c *cpm;
 634        const u32 *data;
 635
 636        cpm = kzalloc(sizeof(struct cpm_i2c), GFP_KERNEL);
 637        if (!cpm)
 638                return -ENOMEM;
 639
 640        cpm->ofdev = ofdev;
 641
 642        platform_set_drvdata(ofdev, cpm);
 643
 644        cpm->adap = cpm_ops;
 645        i2c_set_adapdata(&cpm->adap, cpm);
 646        cpm->adap.dev.parent = &ofdev->dev;
 647        cpm->adap.dev.of_node = of_node_get(ofdev->dev.of_node);
 648
 649        result = cpm_i2c_setup(cpm);
 650        if (result) {
 651                dev_err(&ofdev->dev, "Unable to init hardware\n");
 652                goto out_free;
 653        }
 654
 655        /* register new adapter to i2c module... */
 656
 657        data = of_get_property(ofdev->dev.of_node, "linux,i2c-index", &len);
 658        cpm->adap.nr = (data && len == 4) ? be32_to_cpup(data) : -1;
 659        result = i2c_add_numbered_adapter(&cpm->adap);
 660
 661        if (result < 0)
 662                goto out_shut;
 663
 664        dev_dbg(&ofdev->dev, "hw routines for %s registered.\n",
 665                cpm->adap.name);
 666
 667        return 0;
 668out_shut:
 669        cpm_i2c_shutdown(cpm);
 670out_free:
 671        kfree(cpm);
 672
 673        return result;
 674}
 675
 676static int cpm_i2c_remove(struct platform_device *ofdev)
 677{
 678        struct cpm_i2c *cpm = platform_get_drvdata(ofdev);
 679
 680        i2c_del_adapter(&cpm->adap);
 681
 682        cpm_i2c_shutdown(cpm);
 683
 684        kfree(cpm);
 685
 686        return 0;
 687}
 688
 689static const struct of_device_id cpm_i2c_match[] = {
 690        {
 691                .compatible = "fsl,cpm1-i2c",
 692        },
 693        {
 694                .compatible = "fsl,cpm2-i2c",
 695        },
 696        {},
 697};
 698
 699MODULE_DEVICE_TABLE(of, cpm_i2c_match);
 700
 701static struct platform_driver cpm_i2c_driver = {
 702        .probe          = cpm_i2c_probe,
 703        .remove         = cpm_i2c_remove,
 704        .driver = {
 705                .name = "fsl-i2c-cpm",
 706                .of_match_table = cpm_i2c_match,
 707        },
 708};
 709
 710module_platform_driver(cpm_i2c_driver);
 711
 712MODULE_AUTHOR("Jochen Friedrich <jochen@scram.de>");
 713MODULE_DESCRIPTION("I2C-Bus adapter routines for CPM boards");
 714MODULE_LICENSE("GPL");
 715