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        /* The following elements are only for CPM2 */
  69        char    res3[4];        /* Reserved */
  70        uint    sdmatmp;        /* Internal */
  71};
  72
  73#define I2COM_START     0x80
  74#define I2COM_MASTER    0x01
  75#define I2CER_TXE       0x10
  76#define I2CER_BUSY      0x04
  77#define I2CER_TXB       0x02
  78#define I2CER_RXB       0x01
  79#define I2MOD_EN        0x01
  80
  81/* I2C Registers */
  82struct i2c_reg {
  83        u8      i2mod;
  84        u8      res1[3];
  85        u8      i2add;
  86        u8      res2[3];
  87        u8      i2brg;
  88        u8      res3[3];
  89        u8      i2com;
  90        u8      res4[3];
  91        u8      i2cer;
  92        u8      res5[3];
  93        u8      i2cmr;
  94};
  95
  96struct cpm_i2c {
  97        char *base;
  98        struct platform_device *ofdev;
  99        struct i2c_adapter adap;
 100        uint dp_addr;
 101        int version; /* CPM1=1, CPM2=2 */
 102        int irq;
 103        int cp_command;
 104        int freq;
 105        struct i2c_reg __iomem *i2c_reg;
 106        struct i2c_ram __iomem *i2c_ram;
 107        u16 i2c_addr;
 108        wait_queue_head_t i2c_wait;
 109        cbd_t __iomem *tbase;
 110        cbd_t __iomem *rbase;
 111        u_char *txbuf[CPM_MAXBD];
 112        u_char *rxbuf[CPM_MAXBD];
 113        dma_addr_t txdma[CPM_MAXBD];
 114        dma_addr_t rxdma[CPM_MAXBD];
 115};
 116
 117static irqreturn_t cpm_i2c_interrupt(int irq, void *dev_id)
 118{
 119        struct cpm_i2c *cpm;
 120        struct i2c_reg __iomem *i2c_reg;
 121        struct i2c_adapter *adap = dev_id;
 122        int i;
 123
 124        cpm = i2c_get_adapdata(dev_id);
 125        i2c_reg = cpm->i2c_reg;
 126
 127        /* Clear interrupt. */
 128        i = in_8(&i2c_reg->i2cer);
 129        out_8(&i2c_reg->i2cer, i);
 130
 131        dev_dbg(&adap->dev, "Interrupt: %x\n", i);
 132
 133        wake_up(&cpm->i2c_wait);
 134
 135        return i ? IRQ_HANDLED : IRQ_NONE;
 136}
 137
 138static void cpm_reset_i2c_params(struct cpm_i2c *cpm)
 139{
 140        struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
 141
 142        /* Set up the I2C parameters in the parameter ram. */
 143        out_be16(&i2c_ram->tbase, (u8 __iomem *)cpm->tbase - DPRAM_BASE);
 144        out_be16(&i2c_ram->rbase, (u8 __iomem *)cpm->rbase - DPRAM_BASE);
 145
 146        if (cpm->version == 1) {
 147                out_8(&i2c_ram->tfcr, I2C_EB);
 148                out_8(&i2c_ram->rfcr, I2C_EB);
 149        } else {
 150                out_8(&i2c_ram->tfcr, I2C_EB_CPM2);
 151                out_8(&i2c_ram->rfcr, I2C_EB_CPM2);
 152        }
 153
 154        out_be16(&i2c_ram->mrblr, CPM_MAX_READ);
 155
 156        out_be32(&i2c_ram->rstate, 0);
 157        out_be32(&i2c_ram->rdp, 0);
 158        out_be16(&i2c_ram->rbptr, 0);
 159        out_be16(&i2c_ram->rbc, 0);
 160        out_be32(&i2c_ram->rxtmp, 0);
 161        out_be32(&i2c_ram->tstate, 0);
 162        out_be32(&i2c_ram->tdp, 0);
 163        out_be16(&i2c_ram->tbptr, 0);
 164        out_be16(&i2c_ram->tbc, 0);
 165        out_be32(&i2c_ram->txtmp, 0);
 166}
 167
 168static void cpm_i2c_force_close(struct i2c_adapter *adap)
 169{
 170        struct cpm_i2c *cpm = i2c_get_adapdata(adap);
 171        struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
 172
 173        dev_dbg(&adap->dev, "cpm_i2c_force_close()\n");
 174
 175        cpm_command(cpm->cp_command, CPM_CR_CLOSE_RX_BD);
 176
 177        out_8(&i2c_reg->i2cmr, 0x00);   /* Disable all interrupts */
 178        out_8(&i2c_reg->i2cer, 0xff);
 179}
 180
 181static void cpm_i2c_parse_message(struct i2c_adapter *adap,
 182        struct i2c_msg *pmsg, int num, int tx, int rx)
 183{
 184        cbd_t __iomem *tbdf;
 185        cbd_t __iomem *rbdf;
 186        u_char addr;
 187        u_char *tb;
 188        u_char *rb;
 189        struct cpm_i2c *cpm = i2c_get_adapdata(adap);
 190
 191        tbdf = cpm->tbase + tx;
 192        rbdf = cpm->rbase + rx;
 193
 194        addr = i2c_8bit_addr_from_msg(pmsg);
 195
 196        tb = cpm->txbuf[tx];
 197        rb = cpm->rxbuf[rx];
 198
 199        /* Align read buffer */
 200        rb = (u_char *) (((ulong) rb + 1) & ~1);
 201
 202        tb[0] = addr;           /* Device address byte w/rw flag */
 203
 204        out_be16(&tbdf->cbd_datlen, pmsg->len + 1);
 205        out_be16(&tbdf->cbd_sc, 0);
 206
 207        if (!(pmsg->flags & I2C_M_NOSTART))
 208                setbits16(&tbdf->cbd_sc, BD_I2C_START);
 209
 210        if (tx + 1 == num)
 211                setbits16(&tbdf->cbd_sc, BD_SC_LAST | BD_SC_WRAP);
 212
 213        if (pmsg->flags & I2C_M_RD) {
 214                /*
 215                 * To read, we need an empty buffer of the proper length.
 216                 * All that is used is the first byte for address, the remainder
 217                 * is just used for timing (and doesn't really have to exist).
 218                 */
 219
 220                dev_dbg(&adap->dev, "cpm_i2c_read(abyte=0x%x)\n", addr);
 221
 222                out_be16(&rbdf->cbd_datlen, 0);
 223                out_be16(&rbdf->cbd_sc, BD_SC_EMPTY | BD_SC_INTRPT);
 224
 225                if (rx + 1 == CPM_MAXBD)
 226                        setbits16(&rbdf->cbd_sc, BD_SC_WRAP);
 227
 228                eieio();
 229                setbits16(&tbdf->cbd_sc, BD_SC_READY);
 230        } else {
 231                dev_dbg(&adap->dev, "cpm_i2c_write(abyte=0x%x)\n", addr);
 232
 233                memcpy(tb+1, pmsg->buf, pmsg->len);
 234
 235                eieio();
 236                setbits16(&tbdf->cbd_sc, BD_SC_READY | BD_SC_INTRPT);
 237        }
 238}
 239
 240static int cpm_i2c_check_message(struct i2c_adapter *adap,
 241        struct i2c_msg *pmsg, int tx, int rx)
 242{
 243        cbd_t __iomem *tbdf;
 244        cbd_t __iomem *rbdf;
 245        u_char *tb;
 246        u_char *rb;
 247        struct cpm_i2c *cpm = i2c_get_adapdata(adap);
 248
 249        tbdf = cpm->tbase + tx;
 250        rbdf = cpm->rbase + rx;
 251
 252        tb = cpm->txbuf[tx];
 253        rb = cpm->rxbuf[rx];
 254
 255        /* Align read buffer */
 256        rb = (u_char *) (((uint) rb + 1) & ~1);
 257
 258        eieio();
 259        if (pmsg->flags & I2C_M_RD) {
 260                dev_dbg(&adap->dev, "tx sc 0x%04x, rx sc 0x%04x\n",
 261                        in_be16(&tbdf->cbd_sc), in_be16(&rbdf->cbd_sc));
 262
 263                if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
 264                        dev_dbg(&adap->dev, "I2C read; No ack\n");
 265                        return -ENXIO;
 266                }
 267                if (in_be16(&rbdf->cbd_sc) & BD_SC_EMPTY) {
 268                        dev_err(&adap->dev,
 269                                "I2C read; complete but rbuf empty\n");
 270                        return -EREMOTEIO;
 271                }
 272                if (in_be16(&rbdf->cbd_sc) & BD_SC_OV) {
 273                        dev_err(&adap->dev, "I2C read; Overrun\n");
 274                        return -EREMOTEIO;
 275                }
 276                memcpy(pmsg->buf, rb, pmsg->len);
 277        } else {
 278                dev_dbg(&adap->dev, "tx sc %d 0x%04x\n", tx,
 279                        in_be16(&tbdf->cbd_sc));
 280
 281                if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
 282                        dev_dbg(&adap->dev, "I2C write; No ack\n");
 283                        return -ENXIO;
 284                }
 285                if (in_be16(&tbdf->cbd_sc) & BD_SC_UN) {
 286                        dev_err(&adap->dev, "I2C write; Underrun\n");
 287                        return -EIO;
 288                }
 289                if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
 290                        dev_err(&adap->dev, "I2C write; Collision\n");
 291                        return -EIO;
 292                }
 293        }
 294        return 0;
 295}
 296
 297static int cpm_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 298{
 299        struct cpm_i2c *cpm = i2c_get_adapdata(adap);
 300        struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
 301        struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
 302        struct i2c_msg *pmsg;
 303        int ret;
 304        int tptr;
 305        int rptr;
 306        cbd_t __iomem *tbdf;
 307        cbd_t __iomem *rbdf;
 308
 309        /* Reset to use first buffer */
 310        out_be16(&i2c_ram->rbptr, in_be16(&i2c_ram->rbase));
 311        out_be16(&i2c_ram->tbptr, in_be16(&i2c_ram->tbase));
 312
 313        tbdf = cpm->tbase;
 314        rbdf = cpm->rbase;
 315
 316        tptr = 0;
 317        rptr = 0;
 318
 319        /*
 320         * If there was a collision in the last i2c transaction,
 321         * Set I2COM_MASTER as it was cleared during collision.
 322         */
 323        if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
 324                out_8(&cpm->i2c_reg->i2com, I2COM_MASTER);
 325        }
 326
 327        while (tptr < num) {
 328                pmsg = &msgs[tptr];
 329                dev_dbg(&adap->dev, "R: %d T: %d\n", rptr, tptr);
 330
 331                cpm_i2c_parse_message(adap, pmsg, num, tptr, rptr);
 332                if (pmsg->flags & I2C_M_RD)
 333                        rptr++;
 334                tptr++;
 335        }
 336        /* Start transfer now */
 337        /* Enable RX/TX/Error interupts */
 338        out_8(&i2c_reg->i2cmr, I2CER_TXE | I2CER_TXB | I2CER_RXB);
 339        out_8(&i2c_reg->i2cer, 0xff);   /* Clear interrupt status */
 340        /* Chip bug, set enable here */
 341        setbits8(&i2c_reg->i2mod, I2MOD_EN);    /* Enable */
 342        /* Begin transmission */
 343        setbits8(&i2c_reg->i2com, I2COM_START);
 344
 345        tptr = 0;
 346        rptr = 0;
 347
 348        while (tptr < num) {
 349                /* Check for outstanding messages */
 350                dev_dbg(&adap->dev, "test ready.\n");
 351                pmsg = &msgs[tptr];
 352                if (pmsg->flags & I2C_M_RD)
 353                        ret = wait_event_timeout(cpm->i2c_wait,
 354                                (in_be16(&tbdf[tptr].cbd_sc) & BD_SC_NAK) ||
 355                                !(in_be16(&rbdf[rptr].cbd_sc) & BD_SC_EMPTY),
 356                                1 * HZ);
 357                else
 358                        ret = wait_event_timeout(cpm->i2c_wait,
 359                                !(in_be16(&tbdf[tptr].cbd_sc) & BD_SC_READY),
 360                                1 * HZ);
 361                if (ret == 0) {
 362                        ret = -EREMOTEIO;
 363                        dev_err(&adap->dev, "I2C transfer: timeout\n");
 364                        goto out_err;
 365                }
 366                if (ret > 0) {
 367                        dev_dbg(&adap->dev, "ready.\n");
 368                        ret = cpm_i2c_check_message(adap, pmsg, tptr, rptr);
 369                        tptr++;
 370                        if (pmsg->flags & I2C_M_RD)
 371                                rptr++;
 372                        if (ret)
 373                                goto out_err;
 374                }
 375        }
 376#ifdef I2C_CHIP_ERRATA
 377        /*
 378         * Chip errata, clear enable. This is not needed on rev D4 CPUs.
 379         * Disabling I2C too early may cause too short stop condition
 380         */
 381        udelay(4);
 382        clrbits8(&i2c_reg->i2mod, I2MOD_EN);
 383#endif
 384        return (num);
 385
 386out_err:
 387        cpm_i2c_force_close(adap);
 388#ifdef I2C_CHIP_ERRATA
 389        /*
 390         * Chip errata, clear enable. This is not needed on rev D4 CPUs.
 391         */
 392        clrbits8(&i2c_reg->i2mod, I2MOD_EN);
 393#endif
 394        return ret;
 395}
 396
 397static u32 cpm_i2c_func(struct i2c_adapter *adap)
 398{
 399        return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
 400}
 401
 402/* -----exported algorithm data: -------------------------------------  */
 403
 404static const struct i2c_algorithm cpm_i2c_algo = {
 405        .master_xfer = cpm_i2c_xfer,
 406        .functionality = cpm_i2c_func,
 407};
 408
 409/* CPM_MAX_READ is also limiting writes according to the code! */
 410static const struct i2c_adapter_quirks cpm_i2c_quirks = {
 411        .max_num_msgs = CPM_MAXBD,
 412        .max_read_len = CPM_MAX_READ,
 413        .max_write_len = CPM_MAX_READ,
 414};
 415
 416static const struct i2c_adapter cpm_ops = {
 417        .owner          = THIS_MODULE,
 418        .name           = "i2c-cpm",
 419        .algo           = &cpm_i2c_algo,
 420        .quirks         = &cpm_i2c_quirks,
 421};
 422
 423static int cpm_i2c_setup(struct cpm_i2c *cpm)
 424{
 425        struct platform_device *ofdev = cpm->ofdev;
 426        const u32 *data;
 427        int len, ret, i;
 428        void __iomem *i2c_base;
 429        cbd_t __iomem *tbdf;
 430        cbd_t __iomem *rbdf;
 431        unsigned char brg;
 432
 433        dev_dbg(&cpm->ofdev->dev, "cpm_i2c_setup()\n");
 434
 435        init_waitqueue_head(&cpm->i2c_wait);
 436
 437        cpm->irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
 438        if (!cpm->irq)
 439                return -EINVAL;
 440
 441        /* Install interrupt handler. */
 442        ret = request_irq(cpm->irq, cpm_i2c_interrupt, 0, "cpm_i2c",
 443                          &cpm->adap);
 444        if (ret)
 445                return ret;
 446
 447        /* I2C parameter RAM */
 448        i2c_base = of_iomap(ofdev->dev.of_node, 1);
 449        if (i2c_base == NULL) {
 450                ret = -EINVAL;
 451                goto out_irq;
 452        }
 453
 454        if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm1-i2c")) {
 455
 456                /* Check for and use a microcode relocation patch. */
 457                cpm->i2c_ram = i2c_base;
 458                cpm->i2c_addr = in_be16(&cpm->i2c_ram->rpbase);
 459
 460                /*
 461                 * Maybe should use cpm_muram_alloc instead of hardcoding
 462                 * this in micropatch.c
 463                 */
 464                if (cpm->i2c_addr) {
 465                        cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
 466                        iounmap(i2c_base);
 467                }
 468
 469                cpm->version = 1;
 470
 471        } else if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm2-i2c")) {
 472                cpm->i2c_addr = cpm_muram_alloc(sizeof(struct i2c_ram), 64);
 473                cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
 474                out_be16(i2c_base, cpm->i2c_addr);
 475                iounmap(i2c_base);
 476
 477                cpm->version = 2;
 478
 479        } else {
 480                iounmap(i2c_base);
 481                ret = -EINVAL;
 482                goto out_irq;
 483        }
 484
 485        /* I2C control/status registers */
 486        cpm->i2c_reg = of_iomap(ofdev->dev.of_node, 0);
 487        if (cpm->i2c_reg == NULL) {
 488                ret = -EINVAL;
 489                goto out_ram;
 490        }
 491
 492        data = of_get_property(ofdev->dev.of_node, "fsl,cpm-command", &len);
 493        if (!data || len != 4) {
 494                ret = -EINVAL;
 495                goto out_reg;
 496        }
 497        cpm->cp_command = *data;
 498
 499        data = of_get_property(ofdev->dev.of_node, "linux,i2c-class", &len);
 500        if (data && len == 4)
 501                cpm->adap.class = *data;
 502
 503        data = of_get_property(ofdev->dev.of_node, "clock-frequency", &len);
 504        if (data && len == 4)
 505                cpm->freq = *data;
 506        else
 507                cpm->freq = 60000; /* use 60kHz i2c clock by default */
 508
 509        /*
 510         * Allocate space for CPM_MAXBD transmit and receive buffer
 511         * descriptors in the DP ram.
 512         */
 513        cpm->dp_addr = cpm_muram_alloc(sizeof(cbd_t) * 2 * CPM_MAXBD, 8);
 514        if (!cpm->dp_addr) {
 515                ret = -ENOMEM;
 516                goto out_reg;
 517        }
 518
 519        cpm->tbase = cpm_muram_addr(cpm->dp_addr);
 520        cpm->rbase = cpm_muram_addr(cpm->dp_addr + sizeof(cbd_t) * CPM_MAXBD);
 521
 522        /* Allocate TX and RX buffers */
 523
 524        tbdf = cpm->tbase;
 525        rbdf = cpm->rbase;
 526
 527        for (i = 0; i < CPM_MAXBD; i++) {
 528                cpm->rxbuf[i] = dma_alloc_coherent(&cpm->ofdev->dev,
 529                                                   CPM_MAX_READ + 1,
 530                                                   &cpm->rxdma[i], GFP_KERNEL);
 531                if (!cpm->rxbuf[i]) {
 532                        ret = -ENOMEM;
 533                        goto out_muram;
 534                }
 535                out_be32(&rbdf[i].cbd_bufaddr, ((cpm->rxdma[i] + 1) & ~1));
 536
 537                cpm->txbuf[i] = dma_alloc_coherent(&cpm->ofdev->dev,
 538                                                   CPM_MAX_READ + 1,
 539                                                   &cpm->txdma[i], GFP_KERNEL);
 540                if (!cpm->txbuf[i]) {
 541                        ret = -ENOMEM;
 542                        goto out_muram;
 543                }
 544                out_be32(&tbdf[i].cbd_bufaddr, cpm->txdma[i]);
 545        }
 546
 547        /* Initialize Tx/Rx parameters. */
 548
 549        cpm_reset_i2c_params(cpm);
 550
 551        dev_dbg(&cpm->ofdev->dev, "i2c_ram 0x%p, i2c_addr 0x%04x, freq %d\n",
 552                cpm->i2c_ram, cpm->i2c_addr, cpm->freq);
 553        dev_dbg(&cpm->ofdev->dev, "tbase 0x%04x, rbase 0x%04x\n",
 554                (u8 __iomem *)cpm->tbase - DPRAM_BASE,
 555                (u8 __iomem *)cpm->rbase - DPRAM_BASE);
 556
 557        cpm_command(cpm->cp_command, CPM_CR_INIT_TRX);
 558
 559        /*
 560         * Select an invalid address. Just make sure we don't use loopback mode
 561         */
 562        out_8(&cpm->i2c_reg->i2add, 0x7f << 1);
 563
 564        /*
 565         * PDIV is set to 00 in i2mod, so brgclk/32 is used as input to the
 566         * i2c baud rate generator. This is divided by 2 x (DIV + 3) to get
 567         * the actual i2c bus frequency.
 568         */
 569        brg = get_brgfreq() / (32 * 2 * cpm->freq) - 3;
 570        out_8(&cpm->i2c_reg->i2brg, brg);
 571
 572        out_8(&cpm->i2c_reg->i2mod, 0x00);
 573        out_8(&cpm->i2c_reg->i2com, I2COM_MASTER);      /* Master mode */
 574
 575        /* Disable interrupts. */
 576        out_8(&cpm->i2c_reg->i2cmr, 0);
 577        out_8(&cpm->i2c_reg->i2cer, 0xff);
 578
 579        return 0;
 580
 581out_muram:
 582        for (i = 0; i < CPM_MAXBD; i++) {
 583                if (cpm->rxbuf[i])
 584                        dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
 585                                cpm->rxbuf[i], cpm->rxdma[i]);
 586                if (cpm->txbuf[i])
 587                        dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
 588                                cpm->txbuf[i], cpm->txdma[i]);
 589        }
 590        cpm_muram_free(cpm->dp_addr);
 591out_reg:
 592        iounmap(cpm->i2c_reg);
 593out_ram:
 594        if ((cpm->version == 1) && (!cpm->i2c_addr))
 595                iounmap(cpm->i2c_ram);
 596        if (cpm->version == 2)
 597                cpm_muram_free(cpm->i2c_addr);
 598out_irq:
 599        free_irq(cpm->irq, &cpm->adap);
 600        return ret;
 601}
 602
 603static void cpm_i2c_shutdown(struct cpm_i2c *cpm)
 604{
 605        int i;
 606
 607        /* Shut down I2C. */
 608        clrbits8(&cpm->i2c_reg->i2mod, I2MOD_EN);
 609
 610        /* Disable interrupts */
 611        out_8(&cpm->i2c_reg->i2cmr, 0);
 612        out_8(&cpm->i2c_reg->i2cer, 0xff);
 613
 614        free_irq(cpm->irq, &cpm->adap);
 615
 616        /* Free all memory */
 617        for (i = 0; i < CPM_MAXBD; i++) {
 618                dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
 619                        cpm->rxbuf[i], cpm->rxdma[i]);
 620                dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
 621                        cpm->txbuf[i], cpm->txdma[i]);
 622        }
 623
 624        cpm_muram_free(cpm->dp_addr);
 625        iounmap(cpm->i2c_reg);
 626
 627        if ((cpm->version == 1) && (!cpm->i2c_addr))
 628                iounmap(cpm->i2c_ram);
 629        if (cpm->version == 2)
 630                cpm_muram_free(cpm->i2c_addr);
 631}
 632
 633static int cpm_i2c_probe(struct platform_device *ofdev)
 634{
 635        int result, len;
 636        struct cpm_i2c *cpm;
 637        const u32 *data;
 638
 639        cpm = kzalloc(sizeof(struct cpm_i2c), GFP_KERNEL);
 640        if (!cpm)
 641                return -ENOMEM;
 642
 643        cpm->ofdev = ofdev;
 644
 645        platform_set_drvdata(ofdev, cpm);
 646
 647        cpm->adap = cpm_ops;
 648        i2c_set_adapdata(&cpm->adap, cpm);
 649        cpm->adap.dev.parent = &ofdev->dev;
 650        cpm->adap.dev.of_node = of_node_get(ofdev->dev.of_node);
 651
 652        result = cpm_i2c_setup(cpm);
 653        if (result) {
 654                dev_err(&ofdev->dev, "Unable to init hardware\n");
 655                goto out_free;
 656        }
 657
 658        /* register new adapter to i2c module... */
 659
 660        data = of_get_property(ofdev->dev.of_node, "linux,i2c-index", &len);
 661        cpm->adap.nr = (data && len == 4) ? be32_to_cpup(data) : -1;
 662        result = i2c_add_numbered_adapter(&cpm->adap);
 663
 664        if (result < 0)
 665                goto out_shut;
 666
 667        dev_dbg(&ofdev->dev, "hw routines for %s registered.\n",
 668                cpm->adap.name);
 669
 670        return 0;
 671out_shut:
 672        cpm_i2c_shutdown(cpm);
 673out_free:
 674        kfree(cpm);
 675
 676        return result;
 677}
 678
 679static int cpm_i2c_remove(struct platform_device *ofdev)
 680{
 681        struct cpm_i2c *cpm = platform_get_drvdata(ofdev);
 682
 683        i2c_del_adapter(&cpm->adap);
 684
 685        cpm_i2c_shutdown(cpm);
 686
 687        kfree(cpm);
 688
 689        return 0;
 690}
 691
 692static const struct of_device_id cpm_i2c_match[] = {
 693        {
 694                .compatible = "fsl,cpm1-i2c",
 695        },
 696        {
 697                .compatible = "fsl,cpm2-i2c",
 698        },
 699        {},
 700};
 701
 702MODULE_DEVICE_TABLE(of, cpm_i2c_match);
 703
 704static struct platform_driver cpm_i2c_driver = {
 705        .probe          = cpm_i2c_probe,
 706        .remove         = cpm_i2c_remove,
 707        .driver = {
 708                .name = "fsl-i2c-cpm",
 709                .of_match_table = cpm_i2c_match,
 710        },
 711};
 712
 713module_platform_driver(cpm_i2c_driver);
 714
 715MODULE_AUTHOR("Jochen Friedrich <jochen@scram.de>");
 716MODULE_DESCRIPTION("I2C-Bus adapter routines for CPM boards");
 717MODULE_LICENSE("GPL");
 718