drivers/i2c/busses/i2c-cpm.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
cpm_i2c_interrupt
cpm_reset_i2c_params
cpm_i2c_force_close
cpm_i2c_parse_message
cpm_i2c_check_message
cpm_i2c_xfer
cpm_i2c_func
cpm_i2c_setup
cpm_i2c_shutdown
cpm_i2c_probe
cpm_i2c_remove
   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. */
  49 struct 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 */
  79 struct 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 
  93 struct 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 
 114 static 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 
 135 static 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 
 165 static 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 
 178 static 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 
 237 static 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 
 294 static 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 
 383 out_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 
 394 static 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 
 401 static 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! */
 407 static 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 
 413 static 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 
 420 static 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 
 578 out_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);
 588 out_reg:
 589         iounmap(cpm->i2c_reg);
 590 out_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);
 595 out_irq:
 596         free_irq(cpm->irq, &cpm->adap);
 597         return ret;
 598 }
 599 
 600 static 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 
 630 static 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;
 668 out_shut:
 669         cpm_i2c_shutdown(cpm);
 670 out_free:
 671         kfree(cpm);
 672 
 673         return result;
 674 }
 675 
 676 static 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 
 689 static 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 
 699 MODULE_DEVICE_TABLE(of, cpm_i2c_match);
 700 
 701 static 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 
 710 module_platform_driver(cpm_i2c_driver);
 711 
 712 MODULE_AUTHOR("Jochen Friedrich <jochen@scram.de>");
 713 MODULE_DESCRIPTION("I2C-Bus adapter routines for CPM boards");
 714 MODULE_LICENSE("GPL");
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/i2c/busses/i2c-cpm.c

DEFINITIONS
