drivers/w1/masters/omap_hdq.c

   1 /*
   2  * drivers/w1/masters/omap_hdq.c
   3  *
   4  * Copyright (C) 2007 Texas Instruments, Inc.
   5  *
   6  * This file is licensed under the terms of the GNU General Public License
   7  * version 2. This program is licensed "as is" without any warranty of any
   8  * kind, whether express or implied.
   9  *
  10  */
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/err.h>
  16 #include <linux/clk.h>
  17 #include <linux/io.h>
  18
  19 #include <asm/irq.h>
  20 #include <mach/hardware.h>
  21
  22 #include "../w1.h"
  23 #include "../w1_int.h"
  24
  25 #define MOD_NAME        "OMAP_HDQ:"
  26
  27 #define OMAP_HDQ_REVISION                       0x00
  28 #define OMAP_HDQ_TX_DATA                        0x04
  29 #define OMAP_HDQ_RX_DATA                        0x08
  30 #define OMAP_HDQ_CTRL_STATUS                    0x0c
  31 #define OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK      (1<<6)
  32 #define OMAP_HDQ_CTRL_STATUS_CLOCKENABLE        (1<<5)
  33 #define OMAP_HDQ_CTRL_STATUS_GO                 (1<<4)
  34 #define OMAP_HDQ_CTRL_STATUS_INITIALIZATION     (1<<2)
  35 #define OMAP_HDQ_CTRL_STATUS_DIR                (1<<1)
  36 #define OMAP_HDQ_CTRL_STATUS_MODE               (1<<0)
  37 #define OMAP_HDQ_INT_STATUS                     0x10
  38 #define OMAP_HDQ_INT_STATUS_TXCOMPLETE          (1<<2)
  39 #define OMAP_HDQ_INT_STATUS_RXCOMPLETE          (1<<1)
  40 #define OMAP_HDQ_INT_STATUS_TIMEOUT             (1<<0)
  41 #define OMAP_HDQ_SYSCONFIG                      0x14
  42 #define OMAP_HDQ_SYSCONFIG_SOFTRESET            (1<<1)
  43 #define OMAP_HDQ_SYSCONFIG_AUTOIDLE             (1<<0)
  44 #define OMAP_HDQ_SYSSTATUS                      0x18
  45 #define OMAP_HDQ_SYSSTATUS_RESETDONE            (1<<0)
  46
  47 #define OMAP_HDQ_FLAG_CLEAR                     0
  48 #define OMAP_HDQ_FLAG_SET                       1
  49 #define OMAP_HDQ_TIMEOUT                        (HZ/5)
  50
  51 #define OMAP_HDQ_MAX_USER                       4
  52
  53 static DECLARE_WAIT_QUEUE_HEAD(hdq_wait_queue);
  54 static int w1_id;
  55
  56 struct hdq_data {
  57         struct device           *dev;
  58         void __iomem            *hdq_base;
  59         /* lock status update */
  60         struct  mutex           hdq_mutex;
  61         int                     hdq_usecount;
  62         struct  clk             *hdq_ick;
  63         struct  clk             *hdq_fck;
  64         u8                      hdq_irqstatus;
  65         /* device lock */
  66         spinlock_t              hdq_spinlock;
  67         /*
  68          * Used to control the call to omap_hdq_get and omap_hdq_put.
  69          * HDQ Protocol: Write the CMD|REG_address first, followed by
  70          * the data wrire or read.
  71          */
  72         int                     init_trans;
  73 };
  74
  75 static int __init omap_hdq_probe(struct platform_device *pdev);
  76 static int omap_hdq_remove(struct platform_device *pdev);
  77
  78 static struct platform_driver omap_hdq_driver = {
  79         .probe =        omap_hdq_probe,
  80         .remove =       omap_hdq_remove,
  81         .driver =       {
  82                 .name = "omap_hdq",
  83         },
  84 };
  85
  86 static u8 omap_w1_read_byte(void *_hdq);
  87 static void omap_w1_write_byte(void *_hdq, u8 byte);
  88 static u8 omap_w1_reset_bus(void *_hdq);
  89 static void omap_w1_search_bus(void *_hdq, struct w1_master *master_dev,
  90                 u8 search_type, w1_slave_found_callback slave_found);
  91
  92
  93 static struct w1_bus_master omap_w1_master = {
  94         .read_byte      = omap_w1_read_byte,
  95         .write_byte     = omap_w1_write_byte,
  96         .reset_bus      = omap_w1_reset_bus,
  97         .search         = omap_w1_search_bus,
  98 };
  99
 100 /* HDQ register I/O routines */
 101 static inline u8 hdq_reg_in(struct hdq_data *hdq_data, u32 offset)
 102 {
 103         return __raw_readb(hdq_data->hdq_base + offset);
 104 }
 105
 106 static inline void hdq_reg_out(struct hdq_data *hdq_data, u32 offset, u8 val)
 107 {
 108         __raw_writeb(val, hdq_data->hdq_base + offset);
 109 }
 110
 111 static inline u8 hdq_reg_merge(struct hdq_data *hdq_data, u32 offset,
 112                         u8 val, u8 mask)
 113 {
 114         u8 new_val = (__raw_readb(hdq_data->hdq_base + offset) & ~mask)
 115                         | (val & mask);
 116         __raw_writeb(new_val, hdq_data->hdq_base + offset);
 117
 118         return new_val;
 119 }
 120
 121 /*
 122  * Wait for one or more bits in flag change.
 123  * HDQ_FLAG_SET: wait until any bit in the flag is set.
 124  * HDQ_FLAG_CLEAR: wait until all bits in the flag are cleared.
 125  * return 0 on success and -ETIMEDOUT in the case of timeout.
 126  */
 127 static int hdq_wait_for_flag(struct hdq_data *hdq_data, u32 offset,
 128                 u8 flag, u8 flag_set, u8 *status)
 129 {
 130         int ret = 0;
 131         unsigned long timeout = jiffies + OMAP_HDQ_TIMEOUT;
 132
 133         if (flag_set == OMAP_HDQ_FLAG_CLEAR) {
 134                 /* wait for the flag clear */
 135                 while (((*status = hdq_reg_in(hdq_data, offset)) & flag)
 136                         && time_before(jiffies, timeout)) {
 137                         schedule_timeout_uninterruptible(1);
 138                 }
 139                 if (*status & flag)
 140                         ret = -ETIMEDOUT;
 141         } else if (flag_set == OMAP_HDQ_FLAG_SET) {
 142                 /* wait for the flag set */
 143                 while (!((*status = hdq_reg_in(hdq_data, offset)) & flag)
 144                         && time_before(jiffies, timeout)) {
 145                         schedule_timeout_uninterruptible(1);
 146                 }
 147                 if (!(*status & flag))
 148                         ret = -ETIMEDOUT;
 149         } else
 150                 return -EINVAL;
 151
 152         return ret;
 153 }
 154
 155 /* write out a byte and fill *status with HDQ_INT_STATUS */
 156 static int hdq_write_byte(struct hdq_data *hdq_data, u8 val, u8 *status)
 157 {
 158         int ret;
 159         u8 tmp_status;
 160         unsigned long irqflags;
 161
 162         *status = 0;
 163
 164         spin_lock_irqsave(&hdq_data->hdq_spinlock, irqflags);
 165         /* clear interrupt flags via a dummy read */
 166         hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS);
 167         /* ISR loads it with new INT_STATUS */
 168         hdq_data->hdq_irqstatus = 0;
 169         spin_unlock_irqrestore(&hdq_data->hdq_spinlock, irqflags);
 170
 171         hdq_reg_out(hdq_data, OMAP_HDQ_TX_DATA, val);
 172
 173         /* set the GO bit */
 174         hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS, OMAP_HDQ_CTRL_STATUS_GO,
 175                 OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_GO);
 176         /* wait for the TXCOMPLETE bit */
 177         ret = wait_event_timeout(hdq_wait_queue,
 178                 hdq_data->hdq_irqstatus, OMAP_HDQ_TIMEOUT);
 179         if (ret == 0) {
 180                 dev_dbg(hdq_data->dev, "TX wait elapsed\n");
 181                 goto out;
 182         }
 183
 184         *status = hdq_data->hdq_irqstatus;
 185         /* check irqstatus */
 186         if (!(*status & OMAP_HDQ_INT_STATUS_TXCOMPLETE)) {
 187                 dev_dbg(hdq_data->dev, "timeout waiting for"
 188                         "TXCOMPLETE/RXCOMPLETE, %x", *status);
 189                 ret = -ETIMEDOUT;
 190                 goto out;
 191         }
 192
 193         /* wait for the GO bit return to zero */
 194         ret = hdq_wait_for_flag(hdq_data, OMAP_HDQ_CTRL_STATUS,
 195                         OMAP_HDQ_CTRL_STATUS_GO,
 196                         OMAP_HDQ_FLAG_CLEAR, &tmp_status);
 197         if (ret) {
 198                 dev_dbg(hdq_data->dev, "timeout waiting GO bit"
 199                         "return to zero, %x", tmp_status);
 200         }
 201
 202 out:
 203         return ret;
 204 }
 205
 206 /* HDQ Interrupt service routine */
 207 static irqreturn_t hdq_isr(int irq, void *_hdq)
 208 {
 209         struct hdq_data *hdq_data = _hdq;
 210         unsigned long irqflags;
 211
 212         spin_lock_irqsave(&hdq_data->hdq_spinlock, irqflags);
 213         hdq_data->hdq_irqstatus = hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS);
 214         spin_unlock_irqrestore(&hdq_data->hdq_spinlock, irqflags);
 215         dev_dbg(hdq_data->dev, "hdq_isr: %x", hdq_data->hdq_irqstatus);
 216
 217         if (hdq_data->hdq_irqstatus &
 218                 (OMAP_HDQ_INT_STATUS_TXCOMPLETE | OMAP_HDQ_INT_STATUS_RXCOMPLETE
 219                 | OMAP_HDQ_INT_STATUS_TIMEOUT)) {
 220                 /* wake up sleeping process */
 221                 wake_up(&hdq_wait_queue);
 222         }
 223
 224         return IRQ_HANDLED;
 225 }
 226
 227 /* HDQ Mode: always return success */
 228 static u8 omap_w1_reset_bus(void *_hdq)
 229 {
 230         return 0;
 231 }
 232
 233 /* W1 search callback function */
 234 static void omap_w1_search_bus(void *_hdq, struct w1_master *master_dev,
 235                 u8 search_type, w1_slave_found_callback slave_found)
 236 {
 237         u64 module_id, rn_le, cs, id;
 238
 239         if (w1_id)
 240                 module_id = w1_id;
 241         else
 242                 module_id = 0x1;
 243
 244         rn_le = cpu_to_le64(module_id);
 245         /*
 246          * HDQ might not obey truly the 1-wire spec.
 247          * So calculate CRC based on module parameter.
 248          */
 249         cs = w1_calc_crc8((u8 *)&rn_le, 7);
 250         id = (cs << 56) | module_id;
 251
 252         slave_found(master_dev, id);
 253 }
 254
 255 static int _omap_hdq_reset(struct hdq_data *hdq_data)
 256 {
 257         int ret;
 258         u8 tmp_status;
 259
 260         hdq_reg_out(hdq_data, OMAP_HDQ_SYSCONFIG, OMAP_HDQ_SYSCONFIG_SOFTRESET);
 261         /*
 262          * Select HDQ mode & enable clocks.
 263          * It is observed that INT flags can't be cleared via a read and GO/INIT
 264          * won't return to zero if interrupt is disabled. So we always enable
 265          * interrupt.
 266          */
 267         hdq_reg_out(hdq_data, OMAP_HDQ_CTRL_STATUS,
 268                 OMAP_HDQ_CTRL_STATUS_CLOCKENABLE |
 269                 OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK);
 270
 271         /* wait for reset to complete */
 272         ret = hdq_wait_for_flag(hdq_data, OMAP_HDQ_SYSSTATUS,
 273                 OMAP_HDQ_SYSSTATUS_RESETDONE, OMAP_HDQ_FLAG_SET, &tmp_status);
 274         if (ret)
 275                 dev_dbg(hdq_data->dev, "timeout waiting HDQ reset, %x",
 276                                 tmp_status);
 277         else {
 278                 hdq_reg_out(hdq_data, OMAP_HDQ_CTRL_STATUS,
 279                         OMAP_HDQ_CTRL_STATUS_CLOCKENABLE |
 280                         OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK);
 281                 hdq_reg_out(hdq_data, OMAP_HDQ_SYSCONFIG,
 282                         OMAP_HDQ_SYSCONFIG_AUTOIDLE);
 283         }
 284
 285         return ret;
 286 }
 287
 288 /* Issue break pulse to the device */
 289 static int omap_hdq_break(struct hdq_data *hdq_data)
 290 {
 291         int ret = 0;
 292         u8 tmp_status;
 293         unsigned long irqflags;
 294
 295         ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
 296         if (ret < 0) {
 297                 dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
 298                 ret = -EINTR;
 299                 goto rtn;
 300         }
 301
 302         spin_lock_irqsave(&hdq_data->hdq_spinlock, irqflags);
 303         /* clear interrupt flags via a dummy read */
 304         hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS);
 305         /* ISR loads it with new INT_STATUS */
 306         hdq_data->hdq_irqstatus = 0;
 307         spin_unlock_irqrestore(&hdq_data->hdq_spinlock, irqflags);
 308
 309         /* set the INIT and GO bit */
 310         hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS,
 311                 OMAP_HDQ_CTRL_STATUS_INITIALIZATION | OMAP_HDQ_CTRL_STATUS_GO,
 312                 OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_INITIALIZATION |
 313                 OMAP_HDQ_CTRL_STATUS_GO);
 314
 315         /* wait for the TIMEOUT bit */
 316         ret = wait_event_timeout(hdq_wait_queue,
 317                 hdq_data->hdq_irqstatus, OMAP_HDQ_TIMEOUT);
 318         if (ret == 0) {
 319                 dev_dbg(hdq_data->dev, "break wait elapsed\n");
 320                 ret = -EINTR;
 321                 goto out;
 322         }
 323
 324         tmp_status = hdq_data->hdq_irqstatus;
 325         /* check irqstatus */
 326         if (!(tmp_status & OMAP_HDQ_INT_STATUS_TIMEOUT)) {
 327                 dev_dbg(hdq_data->dev, "timeout waiting for TIMEOUT, %x",
 328                                 tmp_status);
 329                 ret = -ETIMEDOUT;
 330                 goto out;
 331         }
 332         /*
 333          * wait for both INIT and GO bits rerurn to zero.
 334          * zero wait time expected for interrupt mode.
 335          */
 336         ret = hdq_wait_for_flag(hdq_data, OMAP_HDQ_CTRL_STATUS,
 337                         OMAP_HDQ_CTRL_STATUS_INITIALIZATION |
 338                         OMAP_HDQ_CTRL_STATUS_GO, OMAP_HDQ_FLAG_CLEAR,
 339                         &tmp_status);
 340         if (ret)
 341                 dev_dbg(hdq_data->dev, "timeout waiting INIT&GO bits"
 342                         "return to zero, %x", tmp_status);
 343
 344 out:
 345         mutex_unlock(&hdq_data->hdq_mutex);
 346 rtn:
 347         return ret;
 348 }
 349
 350 static int hdq_read_byte(struct hdq_data *hdq_data, u8 *val)
 351 {
 352         int ret = 0;
 353         u8 status;
 354         unsigned long timeout = jiffies + OMAP_HDQ_TIMEOUT;
 355
 356         ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
 357         if (ret < 0) {
 358                 ret = -EINTR;
 359                 goto rtn;
 360         }
 361
 362         if (!hdq_data->hdq_usecount) {
 363                 ret = -EINVAL;
 364                 goto out;
 365         }
 366
 367         if (!(hdq_data->hdq_irqstatus & OMAP_HDQ_INT_STATUS_RXCOMPLETE)) {
 368                 hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS,
 369                         OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_GO,
 370                         OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_GO);
 371                 /*
 372                  * The RX comes immediately after TX. It
 373                  * triggers another interrupt before we
 374                  * sleep. So we have to wait for RXCOMPLETE bit.
 375                  */
 376                 while (!(hdq_data->hdq_irqstatus
 377                         & OMAP_HDQ_INT_STATUS_RXCOMPLETE)
 378                         && time_before(jiffies, timeout)) {
 379                         schedule_timeout_uninterruptible(1);
 380                 }
 381                 hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS, 0,
 382                         OMAP_HDQ_CTRL_STATUS_DIR);
 383                 status = hdq_data->hdq_irqstatus;
 384                 /* check irqstatus */
 385                 if (!(status & OMAP_HDQ_INT_STATUS_RXCOMPLETE)) {
 386                         dev_dbg(hdq_data->dev, "timeout waiting for"
 387                                 "RXCOMPLETE, %x", status);
 388                         ret = -ETIMEDOUT;
 389                         goto out;
 390                 }
 391         }
 392         /* the data is ready. Read it in! */
 393         *val = hdq_reg_in(hdq_data, OMAP_HDQ_RX_DATA);
 394 out:
 395         mutex_unlock(&hdq_data->hdq_mutex);
 396 rtn:
 397         return 0;
 398
 399 }
 400
 401 /* Enable clocks and set the controller to HDQ mode */
 402 static int omap_hdq_get(struct hdq_data *hdq_data)
 403 {
 404         int ret = 0;
 405
 406         ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
 407         if (ret < 0) {
 408                 ret = -EINTR;
 409                 goto rtn;
 410         }
 411
 412         if (OMAP_HDQ_MAX_USER == hdq_data->hdq_usecount) {
 413                 dev_dbg(hdq_data->dev, "attempt to exceed the max use count");
 414                 ret = -EINVAL;
 415                 goto out;
 416         } else {
 417                 hdq_data->hdq_usecount++;
 418                 try_module_get(THIS_MODULE);
 419                 if (1 == hdq_data->hdq_usecount) {
 420                         if (clk_enable(hdq_data->hdq_ick)) {
 421                                 dev_dbg(hdq_data->dev, "Can not enable ick\n");
 422                                 ret = -ENODEV;
 423                                 goto clk_err;
 424                         }
 425                         if (clk_enable(hdq_data->hdq_fck)) {
 426                                 dev_dbg(hdq_data->dev, "Can not enable fck\n");
 427                                 clk_disable(hdq_data->hdq_ick);
 428                                 ret = -ENODEV;
 429                                 goto clk_err;
 430                         }
 431
 432                         /* make sure HDQ is out of reset */
 433                         if (!(hdq_reg_in(hdq_data, OMAP_HDQ_SYSSTATUS) &
 434                                 OMAP_HDQ_SYSSTATUS_RESETDONE)) {
 435                                 ret = _omap_hdq_reset(hdq_data);
 436                                 if (ret)
 437                                         /* back up the count */
 438                                         hdq_data->hdq_usecount--;
 439                         } else {
 440                                 /* select HDQ mode & enable clocks */
 441                                 hdq_reg_out(hdq_data, OMAP_HDQ_CTRL_STATUS,
 442                                         OMAP_HDQ_CTRL_STATUS_CLOCKENABLE |
 443                                         OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK);
 444                                 hdq_reg_out(hdq_data, OMAP_HDQ_SYSCONFIG,
 445                                         OMAP_HDQ_SYSCONFIG_AUTOIDLE);
 446                                 hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS);
 447                         }
 448                 }
 449         }
 450
 451 clk_err:
 452         clk_put(hdq_data->hdq_ick);
 453         clk_put(hdq_data->hdq_fck);
 454 out:
 455         mutex_unlock(&hdq_data->hdq_mutex);
 456 rtn:
 457         return ret;
 458 }
 459
 460 /* Disable clocks to the module */
 461 static int omap_hdq_put(struct hdq_data *hdq_data)
 462 {
 463         int ret = 0;
 464
 465         ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
 466         if (ret < 0)
 467                 return -EINTR;
 468
 469         if (0 == hdq_data->hdq_usecount) {
 470                 dev_dbg(hdq_data->dev, "attempt to decrement use count"
 471                         "when it is zero");
 472                 ret = -EINVAL;
 473         } else {
 474                 hdq_data->hdq_usecount--;
 475                 module_put(THIS_MODULE);
 476                 if (0 == hdq_data->hdq_usecount) {
 477                         clk_disable(hdq_data->hdq_ick);
 478                         clk_disable(hdq_data->hdq_fck);
 479                 }
 480         }
 481         mutex_unlock(&hdq_data->hdq_mutex);
 482
 483         return ret;
 484 }
 485
 486 /* Read a byte of data from the device */
 487 static u8 omap_w1_read_byte(void *_hdq)
 488 {
 489         struct hdq_data *hdq_data = _hdq;
 490         u8 val = 0;
 491         int ret;
 492
 493         ret = hdq_read_byte(hdq_data, &val);
 494         if (ret) {
 495                 ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
 496                 if (ret < 0) {
 497                         dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
 498                         return -EINTR;
 499                 }
 500                 hdq_data->init_trans = 0;
 501                 mutex_unlock(&hdq_data->hdq_mutex);
 502                 omap_hdq_put(hdq_data);
 503                 return -1;
 504         }
 505
 506         /* Write followed by a read, release the module */
 507         if (hdq_data->init_trans) {
 508                 ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
 509                 if (ret < 0) {
 510                         dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
 511                         return -EINTR;
 512                 }
 513                 hdq_data->init_trans = 0;
 514                 mutex_unlock(&hdq_data->hdq_mutex);
 515                 omap_hdq_put(hdq_data);
 516         }
 517
 518         return val;
 519 }
 520
 521 /* Write a byte of data to the device */
 522 static void omap_w1_write_byte(void *_hdq, u8 byte)
 523 {
 524         struct hdq_data *hdq_data = _hdq;
 525         int ret;
 526         u8 status;
 527
 528         /* First write to initialize the transfer */
 529         if (hdq_data->init_trans == 0)
 530                 omap_hdq_get(hdq_data);
 531
 532         ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
 533         if (ret < 0) {
 534                 dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
 535                 return;
 536         }
 537         hdq_data->init_trans++;
 538         mutex_unlock(&hdq_data->hdq_mutex);
 539
 540         ret = hdq_write_byte(hdq_data, byte, &status);
 541         if (ret == 0) {
 542                 dev_dbg(hdq_data->dev, "TX failure:Ctrl status %x\n", status);
 543                 return;
 544         }
 545
 546         /* Second write, data transfered. Release the module */
 547         if (hdq_data->init_trans > 1) {
 548                 omap_hdq_put(hdq_data);
 549                 ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
 550                 if (ret < 0) {
 551                         dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
 552                         return;
 553                 }
 554                 hdq_data->init_trans = 0;
 555                 mutex_unlock(&hdq_data->hdq_mutex);
 556         }
 557
 558         return;
 559 }
 560
 561 static int __init omap_hdq_probe(struct platform_device *pdev)
 562 {
 563         struct hdq_data *hdq_data;
 564         struct resource *res;
 565         int ret, irq;
 566         u8 rev;
 567
 568         hdq_data = kmalloc(sizeof(*hdq_data), GFP_KERNEL);
 569         if (!hdq_data) {
 570                 dev_dbg(&pdev->dev, "unable to allocate memory\n");
 571                 ret = -ENOMEM;
 572                 goto err_kmalloc;
 573         }
 574
 575         hdq_data->dev = &pdev->dev;
 576         platform_set_drvdata(pdev, hdq_data);
 577
 578         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 579         if (!res) {
 580                 dev_dbg(&pdev->dev, "unable to get resource\n");
 581                 ret = -ENXIO;
 582                 goto err_resource;
 583         }
 584
 585         hdq_data->hdq_base = ioremap(res->start, SZ_4K);
 586         if (!hdq_data->hdq_base) {
 587                 dev_dbg(&pdev->dev, "ioremap failed\n");
 588                 ret = -EINVAL;
 589                 goto err_ioremap;
 590         }
 591
 592         /* get interface & functional clock objects */
 593         hdq_data->hdq_ick = clk_get(&pdev->dev, "ick");
 594         hdq_data->hdq_fck = clk_get(&pdev->dev, "fck");
 595
 596         if (IS_ERR(hdq_data->hdq_ick) || IS_ERR(hdq_data->hdq_fck)) {
 597                 dev_dbg(&pdev->dev, "Can't get HDQ clock objects\n");
 598                 if (IS_ERR(hdq_data->hdq_ick)) {
 599                         ret = PTR_ERR(hdq_data->hdq_ick);
 600                         goto err_clk;
 601                 }
 602                 if (IS_ERR(hdq_data->hdq_fck)) {
 603                         ret = PTR_ERR(hdq_data->hdq_fck);
 604                         clk_put(hdq_data->hdq_ick);
 605                         goto err_clk;
 606                 }
 607         }
 608
 609         hdq_data->hdq_usecount = 0;
 610         mutex_init(&hdq_data->hdq_mutex);
 611
 612         if (clk_enable(hdq_data->hdq_ick)) {
 613                 dev_dbg(&pdev->dev, "Can not enable ick\n");
 614                 ret = -ENODEV;
 615                 goto err_intfclk;
 616         }
 617
 618         if (clk_enable(hdq_data->hdq_fck)) {
 619                 dev_dbg(&pdev->dev, "Can not enable fck\n");
 620                 ret = -ENODEV;
 621                 goto err_fnclk;
 622         }
 623
 624         rev = hdq_reg_in(hdq_data, OMAP_HDQ_REVISION);
 625         dev_info(&pdev->dev, "OMAP HDQ Hardware Rev %c.%c. Driver in %s mode\n",
 626                 (rev >> 4) + '0', (rev & 0x0f) + '0', "Interrupt");
 627
 628         spin_lock_init(&hdq_data->hdq_spinlock);
 629
 630         irq = platform_get_irq(pdev, 0);
 631         if (irq < 0) {
 632                 ret = -ENXIO;
 633                 goto err_irq;
 634         }
 635
 636         ret = request_irq(irq, hdq_isr, IRQF_DISABLED, "omap_hdq", hdq_data);
 637         if (ret < 0) {
 638                 dev_dbg(&pdev->dev, "could not request irq\n");
 639                 goto err_irq;
 640         }
 641
 642         omap_hdq_break(hdq_data);
 643
 644         /* don't clock the HDQ until it is needed */
 645         clk_disable(hdq_data->hdq_ick);
 646         clk_disable(hdq_data->hdq_fck);
 647
 648         omap_w1_master.data = hdq_data;
 649
 650         ret = w1_add_master_device(&omap_w1_master);
 651         if (ret) {
 652                 dev_dbg(&pdev->dev, "Failure in registering w1 master\n");
 653                 goto err_w1;
 654         }
 655
 656         return 0;
 657
 658 err_w1:
 659 err_irq:
 660         clk_disable(hdq_data->hdq_fck);
 661
 662 err_fnclk:
 663         clk_disable(hdq_data->hdq_ick);
 664
 665 err_intfclk:
 666         clk_put(hdq_data->hdq_ick);
 667         clk_put(hdq_data->hdq_fck);
 668
 669 err_clk:
 670         iounmap(hdq_data->hdq_base);
 671
 672 err_ioremap:
 673 err_resource:
 674         platform_set_drvdata(pdev, NULL);
 675         kfree(hdq_data);
 676
 677 err_kmalloc:
 678         return ret;
 679
 680 }
 681
 682 static int omap_hdq_remove(struct platform_device *pdev)
 683 {
 684         struct hdq_data *hdq_data = platform_get_drvdata(pdev);
 685
 686         mutex_lock(&hdq_data->hdq_mutex);
 687
 688         if (hdq_data->hdq_usecount) {
 689                 dev_dbg(&pdev->dev, "removed when use count is not zero\n");
 690                 mutex_unlock(&hdq_data->hdq_mutex);
 691                 return -EBUSY;
 692         }
 693
 694         mutex_unlock(&hdq_data->hdq_mutex);
 695
 696         /* remove module dependency */
 697         clk_put(hdq_data->hdq_ick);
 698         clk_put(hdq_data->hdq_fck);
 699         free_irq(INT_24XX_HDQ_IRQ, hdq_data);
 700         platform_set_drvdata(pdev, NULL);
 701         iounmap(hdq_data->hdq_base);
 702         kfree(hdq_data);
 703
 704         return 0;
 705 }
 706
 707 static int __init
 708 omap_hdq_init(void)
 709 {
 710         return platform_driver_register(&omap_hdq_driver);
 711 }
 712 module_init(omap_hdq_init);
 713
 714 static void __exit
 715 omap_hdq_exit(void)
 716 {
 717         platform_driver_unregister(&omap_hdq_driver);
 718 }
 719 module_exit(omap_hdq_exit);
 720
 721 module_param(w1_id, int, S_IRUSR);
 722 MODULE_PARM_DESC(w1_id, "1-wire id for the slave detection");
 723
 724 MODULE_AUTHOR("Texas Instruments");
 725 MODULE_DESCRIPTION("HDQ driver Library");
 726 MODULE_LICENSE("GPL");