drivers/bus/mhi/core/init.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
   4  *
   5  */
   6
   7 #include <linux/device.h>
   8 #include <linux/dma-direction.h>
   9 #include <linux/dma-mapping.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/list.h>
  12 #include <linux/mhi.h>
  13 #include <linux/mod_devicetable.h>
  14 #include <linux/module.h>
  15 #include <linux/slab.h>
  16 #include <linux/vmalloc.h>
  17 #include <linux/wait.h>
  18 #include "internal.h"
  19
  20 const char * const mhi_ee_str[MHI_EE_MAX] = {
  21         [MHI_EE_PBL] = "PBL",
  22         [MHI_EE_SBL] = "SBL",
  23         [MHI_EE_AMSS] = "AMSS",
  24         [MHI_EE_RDDM] = "RDDM",
  25         [MHI_EE_WFW] = "WFW",
  26         [MHI_EE_PTHRU] = "PASS THRU",
  27         [MHI_EE_EDL] = "EDL",
  28         [MHI_EE_DISABLE_TRANSITION] = "DISABLE",
  29         [MHI_EE_NOT_SUPPORTED] = "NOT SUPPORTED",
  30 };
  31
  32 const char * const dev_state_tran_str[DEV_ST_TRANSITION_MAX] = {
  33         [DEV_ST_TRANSITION_PBL] = "PBL",
  34         [DEV_ST_TRANSITION_READY] = "READY",
  35         [DEV_ST_TRANSITION_SBL] = "SBL",
  36         [DEV_ST_TRANSITION_MISSION_MODE] = "MISSION_MODE",
  37 };
  38
  39 const char * const mhi_state_str[MHI_STATE_MAX] = {
  40         [MHI_STATE_RESET] = "RESET",
  41         [MHI_STATE_READY] = "READY",
  42         [MHI_STATE_M0] = "M0",
  43         [MHI_STATE_M1] = "M1",
  44         [MHI_STATE_M2] = "M2",
  45         [MHI_STATE_M3] = "M3",
  46         [MHI_STATE_M3_FAST] = "M3_FAST",
  47         [MHI_STATE_BHI] = "BHI",
  48         [MHI_STATE_SYS_ERR] = "SYS_ERR",
  49 };
  50
  51 static const char * const mhi_pm_state_str[] = {
  52         [MHI_PM_STATE_DISABLE] = "DISABLE",
  53         [MHI_PM_STATE_POR] = "POR",
  54         [MHI_PM_STATE_M0] = "M0",
  55         [MHI_PM_STATE_M2] = "M2",
  56         [MHI_PM_STATE_M3_ENTER] = "M?->M3",
  57         [MHI_PM_STATE_M3] = "M3",
  58         [MHI_PM_STATE_M3_EXIT] = "M3->M0",
  59         [MHI_PM_STATE_FW_DL_ERR] = "FW DL Error",
  60         [MHI_PM_STATE_SYS_ERR_DETECT] = "SYS_ERR Detect",
  61         [MHI_PM_STATE_SYS_ERR_PROCESS] = "SYS_ERR Process",
  62         [MHI_PM_STATE_SHUTDOWN_PROCESS] = "SHUTDOWN Process",
  63         [MHI_PM_STATE_LD_ERR_FATAL_DETECT] = "LD or Error Fatal Detect",
  64 };
  65
  66 const char *to_mhi_pm_state_str(enum mhi_pm_state state)
  67 {
  68         int index = find_last_bit((unsigned long *)&state, 32);
  69
  70         if (index >= ARRAY_SIZE(mhi_pm_state_str))
  71                 return "Invalid State";
  72
  73         return mhi_pm_state_str[index];
  74 }
  75
  76 /* MHI protocol requires the transfer ring to be aligned with ring length */
  77 static int mhi_alloc_aligned_ring(struct mhi_controller *mhi_cntrl,
  78                                   struct mhi_ring *ring,
  79                                   u64 len)
  80 {
  81         ring->alloc_size = len + (len - 1);
  82         ring->pre_aligned = mhi_alloc_coherent(mhi_cntrl, ring->alloc_size,
  83                                                &ring->dma_handle, GFP_KERNEL);
  84         if (!ring->pre_aligned)
  85                 return -ENOMEM;
  86
  87         ring->iommu_base = (ring->dma_handle + (len - 1)) & ~(len - 1);
  88         ring->base = ring->pre_aligned + (ring->iommu_base - ring->dma_handle);
  89
  90         return 0;
  91 }
  92
  93 void mhi_deinit_free_irq(struct mhi_controller *mhi_cntrl)
  94 {
  95         int i;
  96         struct mhi_event *mhi_event = mhi_cntrl->mhi_event;
  97
  98         for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
  99                 if (mhi_event->offload_ev)
 100                         continue;
 101
 102                 free_irq(mhi_cntrl->irq[mhi_event->irq], mhi_event);
 103         }
 104
 105         free_irq(mhi_cntrl->irq[0], mhi_cntrl);
 106 }
 107
 108 int mhi_init_irq_setup(struct mhi_controller *mhi_cntrl)
 109 {
 110         struct mhi_event *mhi_event = mhi_cntrl->mhi_event;
 111         struct device *dev = &mhi_cntrl->mhi_dev->dev;
 112         int i, ret;
 113
 114         /* Setup BHI_INTVEC IRQ */
 115         ret = request_threaded_irq(mhi_cntrl->irq[0], mhi_intvec_handler,
 116                                    mhi_intvec_threaded_handler,
 117                                    IRQF_SHARED | IRQF_NO_SUSPEND,
 118                                    "bhi", mhi_cntrl);
 119         if (ret)
 120                 return ret;
 121
 122         for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
 123                 if (mhi_event->offload_ev)
 124                         continue;
 125
 126                 ret = request_irq(mhi_cntrl->irq[mhi_event->irq],
 127                                   mhi_irq_handler,
 128                                   IRQF_SHARED | IRQF_NO_SUSPEND,
 129                                   "mhi", mhi_event);
 130                 if (ret) {
 131                         dev_err(dev, "Error requesting irq:%d for ev:%d\n",
 132                                 mhi_cntrl->irq[mhi_event->irq], i);
 133                         goto error_request;
 134                 }
 135         }
 136
 137         return 0;
 138
 139 error_request:
 140         for (--i, --mhi_event; i >= 0; i--, mhi_event--) {
 141                 if (mhi_event->offload_ev)
 142                         continue;
 143
 144                 free_irq(mhi_cntrl->irq[mhi_event->irq], mhi_event);
 145         }
 146         free_irq(mhi_cntrl->irq[0], mhi_cntrl);
 147
 148         return ret;
 149 }
 150
 151 void mhi_deinit_dev_ctxt(struct mhi_controller *mhi_cntrl)
 152 {
 153         int i;
 154         struct mhi_ctxt *mhi_ctxt = mhi_cntrl->mhi_ctxt;
 155         struct mhi_cmd *mhi_cmd;
 156         struct mhi_event *mhi_event;
 157         struct mhi_ring *ring;
 158
 159         mhi_cmd = mhi_cntrl->mhi_cmd;
 160         for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++) {
 161                 ring = &mhi_cmd->ring;
 162                 mhi_free_coherent(mhi_cntrl, ring->alloc_size,
 163                                   ring->pre_aligned, ring->dma_handle);
 164                 ring->base = NULL;
 165                 ring->iommu_base = 0;
 166         }
 167
 168         mhi_free_coherent(mhi_cntrl,
 169                           sizeof(*mhi_ctxt->cmd_ctxt) * NR_OF_CMD_RINGS,
 170                           mhi_ctxt->cmd_ctxt, mhi_ctxt->cmd_ctxt_addr);
 171
 172         mhi_event = mhi_cntrl->mhi_event;
 173         for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
 174                 if (mhi_event->offload_ev)
 175                         continue;
 176
 177                 ring = &mhi_event->ring;
 178                 mhi_free_coherent(mhi_cntrl, ring->alloc_size,
 179                                   ring->pre_aligned, ring->dma_handle);
 180                 ring->base = NULL;
 181                 ring->iommu_base = 0;
 182         }
 183
 184         mhi_free_coherent(mhi_cntrl, sizeof(*mhi_ctxt->er_ctxt) *
 185                           mhi_cntrl->total_ev_rings, mhi_ctxt->er_ctxt,
 186                           mhi_ctxt->er_ctxt_addr);
 187
 188         mhi_free_coherent(mhi_cntrl, sizeof(*mhi_ctxt->chan_ctxt) *
 189                           mhi_cntrl->max_chan, mhi_ctxt->chan_ctxt,
 190                           mhi_ctxt->chan_ctxt_addr);
 191
 192         kfree(mhi_ctxt);
 193         mhi_cntrl->mhi_ctxt = NULL;
 194 }
 195
 196 int mhi_init_dev_ctxt(struct mhi_controller *mhi_cntrl)
 197 {
 198         struct mhi_ctxt *mhi_ctxt;
 199         struct mhi_chan_ctxt *chan_ctxt;
 200         struct mhi_event_ctxt *er_ctxt;
 201         struct mhi_cmd_ctxt *cmd_ctxt;
 202         struct mhi_chan *mhi_chan;
 203         struct mhi_event *mhi_event;
 204         struct mhi_cmd *mhi_cmd;
 205         u32 tmp;
 206         int ret = -ENOMEM, i;
 207
 208         atomic_set(&mhi_cntrl->dev_wake, 0);
 209         atomic_set(&mhi_cntrl->pending_pkts, 0);
 210
 211         mhi_ctxt = kzalloc(sizeof(*mhi_ctxt), GFP_KERNEL);
 212         if (!mhi_ctxt)
 213                 return -ENOMEM;
 214
 215         /* Setup channel ctxt */
 216         mhi_ctxt->chan_ctxt = mhi_alloc_coherent(mhi_cntrl,
 217                                                  sizeof(*mhi_ctxt->chan_ctxt) *
 218                                                  mhi_cntrl->max_chan,
 219                                                  &mhi_ctxt->chan_ctxt_addr,
 220                                                  GFP_KERNEL);
 221         if (!mhi_ctxt->chan_ctxt)
 222                 goto error_alloc_chan_ctxt;
 223
 224         mhi_chan = mhi_cntrl->mhi_chan;
 225         chan_ctxt = mhi_ctxt->chan_ctxt;
 226         for (i = 0; i < mhi_cntrl->max_chan; i++, chan_ctxt++, mhi_chan++) {
 227                 /* Skip if it is an offload channel */
 228                 if (mhi_chan->offload_ch)
 229                         continue;
 230
 231                 tmp = chan_ctxt->chcfg;
 232                 tmp &= ~CHAN_CTX_CHSTATE_MASK;
 233                 tmp |= (MHI_CH_STATE_DISABLED << CHAN_CTX_CHSTATE_SHIFT);
 234                 tmp &= ~CHAN_CTX_BRSTMODE_MASK;
 235                 tmp |= (mhi_chan->db_cfg.brstmode << CHAN_CTX_BRSTMODE_SHIFT);
 236                 tmp &= ~CHAN_CTX_POLLCFG_MASK;
 237                 tmp |= (mhi_chan->db_cfg.pollcfg << CHAN_CTX_POLLCFG_SHIFT);
 238                 chan_ctxt->chcfg = tmp;
 239
 240                 chan_ctxt->chtype = mhi_chan->type;
 241                 chan_ctxt->erindex = mhi_chan->er_index;
 242
 243                 mhi_chan->ch_state = MHI_CH_STATE_DISABLED;
 244                 mhi_chan->tre_ring.db_addr = (void __iomem *)&chan_ctxt->wp;
 245         }
 246
 247         /* Setup event context */
 248         mhi_ctxt->er_ctxt = mhi_alloc_coherent(mhi_cntrl,
 249                                                sizeof(*mhi_ctxt->er_ctxt) *
 250                                                mhi_cntrl->total_ev_rings,
 251                                                &mhi_ctxt->er_ctxt_addr,
 252                                                GFP_KERNEL);
 253         if (!mhi_ctxt->er_ctxt)
 254                 goto error_alloc_er_ctxt;
 255
 256         er_ctxt = mhi_ctxt->er_ctxt;
 257         mhi_event = mhi_cntrl->mhi_event;
 258         for (i = 0; i < mhi_cntrl->total_ev_rings; i++, er_ctxt++,
 259                      mhi_event++) {
 260                 struct mhi_ring *ring = &mhi_event->ring;
 261
 262                 /* Skip if it is an offload event */
 263                 if (mhi_event->offload_ev)
 264                         continue;
 265
 266                 tmp = er_ctxt->intmod;
 267                 tmp &= ~EV_CTX_INTMODC_MASK;
 268                 tmp &= ~EV_CTX_INTMODT_MASK;
 269                 tmp |= (mhi_event->intmod << EV_CTX_INTMODT_SHIFT);
 270                 er_ctxt->intmod = tmp;
 271
 272                 er_ctxt->ertype = MHI_ER_TYPE_VALID;
 273                 er_ctxt->msivec = mhi_event->irq;
 274                 mhi_event->db_cfg.db_mode = true;
 275
 276                 ring->el_size = sizeof(struct mhi_tre);
 277                 ring->len = ring->el_size * ring->elements;
 278                 ret = mhi_alloc_aligned_ring(mhi_cntrl, ring, ring->len);
 279                 if (ret)
 280                         goto error_alloc_er;
 281
 282                 /*
 283                  * If the read pointer equals to the write pointer, then the
 284                  * ring is empty
 285                  */
 286                 ring->rp = ring->wp = ring->base;
 287                 er_ctxt->rbase = ring->iommu_base;
 288                 er_ctxt->rp = er_ctxt->wp = er_ctxt->rbase;
 289                 er_ctxt->rlen = ring->len;
 290                 ring->ctxt_wp = &er_ctxt->wp;
 291         }
 292
 293         /* Setup cmd context */
 294         mhi_ctxt->cmd_ctxt = mhi_alloc_coherent(mhi_cntrl,
 295                                                 sizeof(*mhi_ctxt->cmd_ctxt) *
 296                                                 NR_OF_CMD_RINGS,
 297                                                 &mhi_ctxt->cmd_ctxt_addr,
 298                                                 GFP_KERNEL);
 299         if (!mhi_ctxt->cmd_ctxt)
 300                 goto error_alloc_er;
 301
 302         mhi_cmd = mhi_cntrl->mhi_cmd;
 303         cmd_ctxt = mhi_ctxt->cmd_ctxt;
 304         for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++, cmd_ctxt++) {
 305                 struct mhi_ring *ring = &mhi_cmd->ring;
 306
 307                 ring->el_size = sizeof(struct mhi_tre);
 308                 ring->elements = CMD_EL_PER_RING;
 309                 ring->len = ring->el_size * ring->elements;
 310                 ret = mhi_alloc_aligned_ring(mhi_cntrl, ring, ring->len);
 311                 if (ret)
 312                         goto error_alloc_cmd;
 313
 314                 ring->rp = ring->wp = ring->base;
 315                 cmd_ctxt->rbase = ring->iommu_base;
 316                 cmd_ctxt->rp = cmd_ctxt->wp = cmd_ctxt->rbase;
 317                 cmd_ctxt->rlen = ring->len;
 318                 ring->ctxt_wp = &cmd_ctxt->wp;
 319         }
 320
 321         mhi_cntrl->mhi_ctxt = mhi_ctxt;
 322
 323         return 0;
 324
 325 error_alloc_cmd:
 326         for (--i, --mhi_cmd; i >= 0; i--, mhi_cmd--) {
 327                 struct mhi_ring *ring = &mhi_cmd->ring;
 328
 329                 mhi_free_coherent(mhi_cntrl, ring->alloc_size,
 330                                   ring->pre_aligned, ring->dma_handle);
 331         }
 332         mhi_free_coherent(mhi_cntrl,
 333                           sizeof(*mhi_ctxt->cmd_ctxt) * NR_OF_CMD_RINGS,
 334                           mhi_ctxt->cmd_ctxt, mhi_ctxt->cmd_ctxt_addr);
 335         i = mhi_cntrl->total_ev_rings;
 336         mhi_event = mhi_cntrl->mhi_event + i;
 337
 338 error_alloc_er:
 339         for (--i, --mhi_event; i >= 0; i--, mhi_event--) {
 340                 struct mhi_ring *ring = &mhi_event->ring;
 341
 342                 if (mhi_event->offload_ev)
 343                         continue;
 344
 345                 mhi_free_coherent(mhi_cntrl, ring->alloc_size,
 346                                   ring->pre_aligned, ring->dma_handle);
 347         }
 348         mhi_free_coherent(mhi_cntrl, sizeof(*mhi_ctxt->er_ctxt) *
 349                           mhi_cntrl->total_ev_rings, mhi_ctxt->er_ctxt,
 350                           mhi_ctxt->er_ctxt_addr);
 351
 352 error_alloc_er_ctxt:
 353         mhi_free_coherent(mhi_cntrl, sizeof(*mhi_ctxt->chan_ctxt) *
 354                           mhi_cntrl->max_chan, mhi_ctxt->chan_ctxt,
 355                           mhi_ctxt->chan_ctxt_addr);
 356
 357 error_alloc_chan_ctxt:
 358         kfree(mhi_ctxt);
 359
 360         return ret;
 361 }
 362
 363 int mhi_init_mmio(struct mhi_controller *mhi_cntrl)
 364 {
 365         u32 val;
 366         int i, ret;
 367         struct mhi_chan *mhi_chan;
 368         struct mhi_event *mhi_event;
 369         void __iomem *base = mhi_cntrl->regs;
 370         struct device *dev = &mhi_cntrl->mhi_dev->dev;
 371         struct {
 372                 u32 offset;
 373                 u32 mask;
 374                 u32 shift;
 375                 u32 val;
 376         } reg_info[] = {
 377                 {
 378                         CCABAP_HIGHER, U32_MAX, 0,
 379                         upper_32_bits(mhi_cntrl->mhi_ctxt->chan_ctxt_addr),
 380                 },
 381                 {
 382                         CCABAP_LOWER, U32_MAX, 0,
 383                         lower_32_bits(mhi_cntrl->mhi_ctxt->chan_ctxt_addr),
 384                 },
 385                 {
 386                         ECABAP_HIGHER, U32_MAX, 0,
 387                         upper_32_bits(mhi_cntrl->mhi_ctxt->er_ctxt_addr),
 388                 },
 389                 {
 390                         ECABAP_LOWER, U32_MAX, 0,
 391                         lower_32_bits(mhi_cntrl->mhi_ctxt->er_ctxt_addr),
 392                 },
 393                 {
 394                         CRCBAP_HIGHER, U32_MAX, 0,
 395                         upper_32_bits(mhi_cntrl->mhi_ctxt->cmd_ctxt_addr),
 396                 },
 397                 {
 398                         CRCBAP_LOWER, U32_MAX, 0,
 399                         lower_32_bits(mhi_cntrl->mhi_ctxt->cmd_ctxt_addr),
 400                 },
 401                 {
 402                         MHICFG, MHICFG_NER_MASK, MHICFG_NER_SHIFT,
 403                         mhi_cntrl->total_ev_rings,
 404                 },
 405                 {
 406                         MHICFG, MHICFG_NHWER_MASK, MHICFG_NHWER_SHIFT,
 407                         mhi_cntrl->hw_ev_rings,
 408                 },
 409                 {
 410                         MHICTRLBASE_HIGHER, U32_MAX, 0,
 411                         upper_32_bits(mhi_cntrl->iova_start),
 412                 },
 413                 {
 414                         MHICTRLBASE_LOWER, U32_MAX, 0,
 415                         lower_32_bits(mhi_cntrl->iova_start),
 416                 },
 417                 {
 418                         MHIDATABASE_HIGHER, U32_MAX, 0,
 419                         upper_32_bits(mhi_cntrl->iova_start),
 420                 },
 421                 {
 422                         MHIDATABASE_LOWER, U32_MAX, 0,
 423                         lower_32_bits(mhi_cntrl->iova_start),
 424                 },
 425                 {
 426                         MHICTRLLIMIT_HIGHER, U32_MAX, 0,
 427                         upper_32_bits(mhi_cntrl->iova_stop),
 428                 },
 429                 {
 430                         MHICTRLLIMIT_LOWER, U32_MAX, 0,
 431                         lower_32_bits(mhi_cntrl->iova_stop),
 432                 },
 433                 {
 434                         MHIDATALIMIT_HIGHER, U32_MAX, 0,
 435                         upper_32_bits(mhi_cntrl->iova_stop),
 436                 },
 437                 {
 438                         MHIDATALIMIT_LOWER, U32_MAX, 0,
 439                         lower_32_bits(mhi_cntrl->iova_stop),
 440                 },
 441                 { 0, 0, 0 }
 442         };
 443
 444         dev_dbg(dev, "Initializing MHI registers\n");
 445
 446         /* Read channel db offset */
 447         ret = mhi_read_reg_field(mhi_cntrl, base, CHDBOFF, CHDBOFF_CHDBOFF_MASK,
 448                                  CHDBOFF_CHDBOFF_SHIFT, &val);
 449         if (ret) {
 450                 dev_err(dev, "Unable to read CHDBOFF register\n");
 451                 return -EIO;
 452         }
 453
 454         /* Setup wake db */
 455         mhi_cntrl->wake_db = base + val + (8 * MHI_DEV_WAKE_DB);
 456         mhi_write_reg(mhi_cntrl, mhi_cntrl->wake_db, 4, 0);
 457         mhi_write_reg(mhi_cntrl, mhi_cntrl->wake_db, 0, 0);
 458         mhi_cntrl->wake_set = false;
 459
 460         /* Setup channel db address for each channel in tre_ring */
 461         mhi_chan = mhi_cntrl->mhi_chan;
 462         for (i = 0; i < mhi_cntrl->max_chan; i++, val += 8, mhi_chan++)
 463                 mhi_chan->tre_ring.db_addr = base + val;
 464
 465         /* Read event ring db offset */
 466         ret = mhi_read_reg_field(mhi_cntrl, base, ERDBOFF, ERDBOFF_ERDBOFF_MASK,
 467                                  ERDBOFF_ERDBOFF_SHIFT, &val);
 468         if (ret) {
 469                 dev_err(dev, "Unable to read ERDBOFF register\n");
 470                 return -EIO;
 471         }
 472
 473         /* Setup event db address for each ev_ring */
 474         mhi_event = mhi_cntrl->mhi_event;
 475         for (i = 0; i < mhi_cntrl->total_ev_rings; i++, val += 8, mhi_event++) {
 476                 if (mhi_event->offload_ev)
 477                         continue;
 478
 479                 mhi_event->ring.db_addr = base + val;
 480         }
 481
 482         /* Setup DB register for primary CMD rings */
 483         mhi_cntrl->mhi_cmd[PRIMARY_CMD_RING].ring.db_addr = base + CRDB_LOWER;
 484
 485         /* Write to MMIO registers */
 486         for (i = 0; reg_info[i].offset; i++)
 487                 mhi_write_reg_field(mhi_cntrl, base, reg_info[i].offset,
 488                                     reg_info[i].mask, reg_info[i].shift,
 489                                     reg_info[i].val);
 490
 491         return 0;
 492 }
 493
 494 void mhi_deinit_chan_ctxt(struct mhi_controller *mhi_cntrl,
 495                           struct mhi_chan *mhi_chan)
 496 {
 497         struct mhi_ring *buf_ring;
 498         struct mhi_ring *tre_ring;
 499         struct mhi_chan_ctxt *chan_ctxt;
 500
 501         buf_ring = &mhi_chan->buf_ring;
 502         tre_ring = &mhi_chan->tre_ring;
 503         chan_ctxt = &mhi_cntrl->mhi_ctxt->chan_ctxt[mhi_chan->chan];
 504
 505         mhi_free_coherent(mhi_cntrl, tre_ring->alloc_size,
 506                           tre_ring->pre_aligned, tre_ring->dma_handle);
 507         vfree(buf_ring->base);
 508
 509         buf_ring->base = tre_ring->base = NULL;
 510         chan_ctxt->rbase = 0;
 511 }
 512
 513 int mhi_init_chan_ctxt(struct mhi_controller *mhi_cntrl,
 514                        struct mhi_chan *mhi_chan)
 515 {
 516         struct mhi_ring *buf_ring;
 517         struct mhi_ring *tre_ring;
 518         struct mhi_chan_ctxt *chan_ctxt;
 519         u32 tmp;
 520         int ret;
 521
 522         buf_ring = &mhi_chan->buf_ring;
 523         tre_ring = &mhi_chan->tre_ring;
 524         tre_ring->el_size = sizeof(struct mhi_tre);
 525         tre_ring->len = tre_ring->el_size * tre_ring->elements;
 526         chan_ctxt = &mhi_cntrl->mhi_ctxt->chan_ctxt[mhi_chan->chan];
 527         ret = mhi_alloc_aligned_ring(mhi_cntrl, tre_ring, tre_ring->len);
 528         if (ret)
 529                 return -ENOMEM;
 530
 531         buf_ring->el_size = sizeof(struct mhi_buf_info);
 532         buf_ring->len = buf_ring->el_size * buf_ring->elements;
 533         buf_ring->base = vzalloc(buf_ring->len);
 534
 535         if (!buf_ring->base) {
 536                 mhi_free_coherent(mhi_cntrl, tre_ring->alloc_size,
 537                                   tre_ring->pre_aligned, tre_ring->dma_handle);
 538                 return -ENOMEM;
 539         }
 540
 541         tmp = chan_ctxt->chcfg;
 542         tmp &= ~CHAN_CTX_CHSTATE_MASK;
 543         tmp |= (MHI_CH_STATE_ENABLED << CHAN_CTX_CHSTATE_SHIFT);
 544         chan_ctxt->chcfg = tmp;
 545
 546         chan_ctxt->rbase = tre_ring->iommu_base;
 547         chan_ctxt->rp = chan_ctxt->wp = chan_ctxt->rbase;
 548         chan_ctxt->rlen = tre_ring->len;
 549         tre_ring->ctxt_wp = &chan_ctxt->wp;
 550
 551         tre_ring->rp = tre_ring->wp = tre_ring->base;
 552         buf_ring->rp = buf_ring->wp = buf_ring->base;
 553         mhi_chan->db_cfg.db_mode = 1;
 554
 555         /* Update to all cores */
 556         smp_wmb();
 557
 558         return 0;
 559 }
 560
 561 static int parse_ev_cfg(struct mhi_controller *mhi_cntrl,
 562                         struct mhi_controller_config *config)
 563 {
 564         struct mhi_event *mhi_event;
 565         struct mhi_event_config *event_cfg;
 566         struct device *dev = &mhi_cntrl->mhi_dev->dev;
 567         int i, num;
 568
 569         num = config->num_events;
 570         mhi_cntrl->total_ev_rings = num;
 571         mhi_cntrl->mhi_event = kcalloc(num, sizeof(*mhi_cntrl->mhi_event),
 572                                        GFP_KERNEL);
 573         if (!mhi_cntrl->mhi_event)
 574                 return -ENOMEM;
 575
 576         /* Populate event ring */
 577         mhi_event = mhi_cntrl->mhi_event;
 578         for (i = 0; i < num; i++) {
 579                 event_cfg = &config->event_cfg[i];
 580
 581                 mhi_event->er_index = i;
 582                 mhi_event->ring.elements = event_cfg->num_elements;
 583                 mhi_event->intmod = event_cfg->irq_moderation_ms;
 584                 mhi_event->irq = event_cfg->irq;
 585
 586                 if (event_cfg->channel != U32_MAX) {
 587                         /* This event ring has a dedicated channel */
 588                         mhi_event->chan = event_cfg->channel;
 589                         if (mhi_event->chan >= mhi_cntrl->max_chan) {
 590                                 dev_err(dev,
 591                                         "Event Ring channel not available\n");
 592                                 goto error_ev_cfg;
 593                         }
 594
 595                         mhi_event->mhi_chan =
 596                                 &mhi_cntrl->mhi_chan[mhi_event->chan];
 597                 }
 598
 599                 /* Priority is fixed to 1 for now */
 600                 mhi_event->priority = 1;
 601
 602                 mhi_event->db_cfg.brstmode = event_cfg->mode;
 603                 if (MHI_INVALID_BRSTMODE(mhi_event->db_cfg.brstmode))
 604                         goto error_ev_cfg;
 605
 606                 if (mhi_event->db_cfg.brstmode == MHI_DB_BRST_ENABLE)
 607                         mhi_event->db_cfg.process_db = mhi_db_brstmode;
 608                 else
 609                         mhi_event->db_cfg.process_db = mhi_db_brstmode_disable;
 610
 611                 mhi_event->data_type = event_cfg->data_type;
 612
 613                 switch (mhi_event->data_type) {
 614                 case MHI_ER_DATA:
 615                         mhi_event->process_event = mhi_process_data_event_ring;
 616                         break;
 617                 case MHI_ER_CTRL:
 618                         mhi_event->process_event = mhi_process_ctrl_ev_ring;
 619                         break;
 620                 default:
 621                         dev_err(dev, "Event Ring type not supported\n");
 622                         goto error_ev_cfg;
 623                 }
 624
 625                 mhi_event->hw_ring = event_cfg->hardware_event;
 626                 if (mhi_event->hw_ring)
 627                         mhi_cntrl->hw_ev_rings++;
 628                 else
 629                         mhi_cntrl->sw_ev_rings++;
 630
 631                 mhi_event->cl_manage = event_cfg->client_managed;
 632                 mhi_event->offload_ev = event_cfg->offload_channel;
 633                 mhi_event++;
 634         }
 635
 636         /* We need IRQ for each event ring + additional one for BHI */
 637         mhi_cntrl->nr_irqs_req = mhi_cntrl->total_ev_rings + 1;
 638
 639         return 0;
 640
 641 error_ev_cfg:
 642
 643         kfree(mhi_cntrl->mhi_event);
 644         return -EINVAL;
 645 }
 646
 647 static int parse_ch_cfg(struct mhi_controller *mhi_cntrl,
 648                         struct mhi_controller_config *config)
 649 {
 650         struct mhi_channel_config *ch_cfg;
 651         struct device *dev = &mhi_cntrl->mhi_dev->dev;
 652         int i;
 653         u32 chan;
 654
 655         mhi_cntrl->max_chan = config->max_channels;
 656
 657         /*
 658          * The allocation of MHI channels can exceed 32KB in some scenarios,
 659          * so to avoid any memory possible allocation failures, vzalloc is
 660          * used here
 661          */
 662         mhi_cntrl->mhi_chan = vzalloc(mhi_cntrl->max_chan *
 663                                       sizeof(*mhi_cntrl->mhi_chan));
 664         if (!mhi_cntrl->mhi_chan)
 665                 return -ENOMEM;
 666
 667         INIT_LIST_HEAD(&mhi_cntrl->lpm_chans);
 668
 669         /* Populate channel configurations */
 670         for (i = 0; i < config->num_channels; i++) {
 671                 struct mhi_chan *mhi_chan;
 672
 673                 ch_cfg = &config->ch_cfg[i];
 674
 675                 chan = ch_cfg->num;
 676                 if (chan >= mhi_cntrl->max_chan) {
 677                         dev_err(dev, "Channel %d not available\n", chan);
 678                         goto error_chan_cfg;
 679                 }
 680
 681                 mhi_chan = &mhi_cntrl->mhi_chan[chan];
 682                 mhi_chan->name = ch_cfg->name;
 683                 mhi_chan->chan = chan;
 684
 685                 mhi_chan->tre_ring.elements = ch_cfg->num_elements;
 686                 if (!mhi_chan->tre_ring.elements)
 687                         goto error_chan_cfg;
 688
 689                 /*
 690                  * For some channels, local ring length should be bigger than
 691                  * the transfer ring length due to internal logical channels
 692                  * in device. So host can queue much more buffers than transfer
 693                  * ring length. Example, RSC channels should have a larger local
 694                  * channel length than transfer ring length.
 695                  */
 696                 mhi_chan->buf_ring.elements = ch_cfg->local_elements;
 697                 if (!mhi_chan->buf_ring.elements)
 698                         mhi_chan->buf_ring.elements = mhi_chan->tre_ring.elements;
 699                 mhi_chan->er_index = ch_cfg->event_ring;
 700                 mhi_chan->dir = ch_cfg->dir;
 701
 702                 /*
 703                  * For most channels, chtype is identical to channel directions.
 704                  * So, if it is not defined then assign channel direction to
 705                  * chtype
 706                  */
 707                 mhi_chan->type = ch_cfg->type;
 708                 if (!mhi_chan->type)
 709                         mhi_chan->type = (enum mhi_ch_type)mhi_chan->dir;
 710
 711                 mhi_chan->ee_mask = ch_cfg->ee_mask;
 712                 mhi_chan->db_cfg.pollcfg = ch_cfg->pollcfg;
 713                 mhi_chan->lpm_notify = ch_cfg->lpm_notify;
 714                 mhi_chan->offload_ch = ch_cfg->offload_channel;
 715                 mhi_chan->db_cfg.reset_req = ch_cfg->doorbell_mode_switch;
 716                 mhi_chan->pre_alloc = ch_cfg->auto_queue;
 717                 mhi_chan->auto_start = ch_cfg->auto_start;
 718
 719                 /*
 720                  * If MHI host allocates buffers, then the channel direction
 721                  * should be DMA_FROM_DEVICE
 722                  */
 723                 if (mhi_chan->pre_alloc && mhi_chan->dir != DMA_FROM_DEVICE) {
 724                         dev_err(dev, "Invalid channel configuration\n");
 725                         goto error_chan_cfg;
 726                 }
 727
 728                 /*
 729                  * Bi-directional and direction less channel must be an
 730                  * offload channel
 731                  */
 732                 if ((mhi_chan->dir == DMA_BIDIRECTIONAL ||
 733                      mhi_chan->dir == DMA_NONE) && !mhi_chan->offload_ch) {
 734                         dev_err(dev, "Invalid channel configuration\n");
 735                         goto error_chan_cfg;
 736                 }
 737
 738                 if (!mhi_chan->offload_ch) {
 739                         mhi_chan->db_cfg.brstmode = ch_cfg->doorbell;
 740                         if (MHI_INVALID_BRSTMODE(mhi_chan->db_cfg.brstmode)) {
 741                                 dev_err(dev, "Invalid Door bell mode\n");
 742                                 goto error_chan_cfg;
 743                         }
 744                 }
 745
 746                 if (mhi_chan->db_cfg.brstmode == MHI_DB_BRST_ENABLE)
 747                         mhi_chan->db_cfg.process_db = mhi_db_brstmode;
 748                 else
 749                         mhi_chan->db_cfg.process_db = mhi_db_brstmode_disable;
 750
 751                 mhi_chan->configured = true;
 752
 753                 if (mhi_chan->lpm_notify)
 754                         list_add_tail(&mhi_chan->node, &mhi_cntrl->lpm_chans);
 755         }
 756
 757         return 0;
 758
 759 error_chan_cfg:
 760         vfree(mhi_cntrl->mhi_chan);
 761
 762         return -EINVAL;
 763 }
 764
 765 static int parse_config(struct mhi_controller *mhi_cntrl,
 766                         struct mhi_controller_config *config)
 767 {
 768         int ret;
 769
 770         /* Parse MHI channel configuration */
 771         ret = parse_ch_cfg(mhi_cntrl, config);
 772         if (ret)
 773                 return ret;
 774
 775         /* Parse MHI event configuration */
 776         ret = parse_ev_cfg(mhi_cntrl, config);
 777         if (ret)
 778                 goto error_ev_cfg;
 779
 780         mhi_cntrl->timeout_ms = config->timeout_ms;
 781         if (!mhi_cntrl->timeout_ms)
 782                 mhi_cntrl->timeout_ms = MHI_TIMEOUT_MS;
 783
 784         mhi_cntrl->bounce_buf = config->use_bounce_buf;
 785         mhi_cntrl->buffer_len = config->buf_len;
 786         if (!mhi_cntrl->buffer_len)
 787                 mhi_cntrl->buffer_len = MHI_MAX_MTU;
 788
 789         /* By default, host is allowed to ring DB in both M0 and M2 states */
 790         mhi_cntrl->db_access = MHI_PM_M0 | MHI_PM_M2;
 791         if (config->m2_no_db)
 792                 mhi_cntrl->db_access &= ~MHI_PM_M2;
 793
 794         return 0;
 795
 796 error_ev_cfg:
 797         vfree(mhi_cntrl->mhi_chan);
 798
 799         return ret;
 800 }
 801
 802 int mhi_register_controller(struct mhi_controller *mhi_cntrl,
 803                             struct mhi_controller_config *config)
 804 {
 805         struct mhi_event *mhi_event;
 806         struct mhi_chan *mhi_chan;
 807         struct mhi_cmd *mhi_cmd;
 808         struct mhi_device *mhi_dev;
 809         u32 soc_info;
 810         int ret, i;
 811
 812         if (!mhi_cntrl)
 813                 return -EINVAL;
 814
 815         if (!mhi_cntrl->runtime_get || !mhi_cntrl->runtime_put ||
 816             !mhi_cntrl->status_cb || !mhi_cntrl->read_reg ||
 817             !mhi_cntrl->write_reg)
 818                 return -EINVAL;
 819
 820         ret = parse_config(mhi_cntrl, config);
 821         if (ret)
 822                 return -EINVAL;
 823
 824         mhi_cntrl->mhi_cmd = kcalloc(NR_OF_CMD_RINGS,
 825                                      sizeof(*mhi_cntrl->mhi_cmd), GFP_KERNEL);
 826         if (!mhi_cntrl->mhi_cmd) {
 827                 ret = -ENOMEM;
 828                 goto error_alloc_cmd;
 829         }
 830
 831         INIT_LIST_HEAD(&mhi_cntrl->transition_list);
 832         mutex_init(&mhi_cntrl->pm_mutex);
 833         rwlock_init(&mhi_cntrl->pm_lock);
 834         spin_lock_init(&mhi_cntrl->transition_lock);
 835         spin_lock_init(&mhi_cntrl->wlock);
 836         INIT_WORK(&mhi_cntrl->st_worker, mhi_pm_st_worker);
 837         INIT_WORK(&mhi_cntrl->syserr_worker, mhi_pm_sys_err_worker);
 838         INIT_WORK(&mhi_cntrl->fw_worker, mhi_fw_load_worker);
 839         init_waitqueue_head(&mhi_cntrl->state_event);
 840
 841         mhi_cmd = mhi_cntrl->mhi_cmd;
 842         for (i = 0; i < NR_OF_CMD_RINGS; i++, mhi_cmd++)
 843                 spin_lock_init(&mhi_cmd->lock);
 844
 845         mhi_event = mhi_cntrl->mhi_event;
 846         for (i = 0; i < mhi_cntrl->total_ev_rings; i++, mhi_event++) {
 847                 /* Skip for offload events */
 848                 if (mhi_event->offload_ev)
 849                         continue;
 850
 851                 mhi_event->mhi_cntrl = mhi_cntrl;
 852                 spin_lock_init(&mhi_event->lock);
 853                 if (mhi_event->data_type == MHI_ER_CTRL)
 854                         tasklet_init(&mhi_event->task, mhi_ctrl_ev_task,
 855                                      (ulong)mhi_event);
 856                 else
 857                         tasklet_init(&mhi_event->task, mhi_ev_task,
 858                                      (ulong)mhi_event);
 859         }
 860
 861         mhi_chan = mhi_cntrl->mhi_chan;
 862         for (i = 0; i < mhi_cntrl->max_chan; i++, mhi_chan++) {
 863                 mutex_init(&mhi_chan->mutex);
 864                 init_completion(&mhi_chan->completion);
 865                 rwlock_init(&mhi_chan->lock);
 866         }
 867
 868         if (mhi_cntrl->bounce_buf) {
 869                 mhi_cntrl->map_single = mhi_map_single_use_bb;
 870                 mhi_cntrl->unmap_single = mhi_unmap_single_use_bb;
 871         } else {
 872                 mhi_cntrl->map_single = mhi_map_single_no_bb;
 873                 mhi_cntrl->unmap_single = mhi_unmap_single_no_bb;
 874         }
 875
 876         /* Read the MHI device info */
 877         ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs,
 878                            SOC_HW_VERSION_OFFS, &soc_info);
 879         if (ret)
 880                 goto error_alloc_dev;
 881
 882         mhi_cntrl->family_number = (soc_info & SOC_HW_VERSION_FAM_NUM_BMSK) >>
 883                                         SOC_HW_VERSION_FAM_NUM_SHFT;
 884         mhi_cntrl->device_number = (soc_info & SOC_HW_VERSION_DEV_NUM_BMSK) >>
 885                                         SOC_HW_VERSION_DEV_NUM_SHFT;
 886         mhi_cntrl->major_version = (soc_info & SOC_HW_VERSION_MAJOR_VER_BMSK) >>
 887                                         SOC_HW_VERSION_MAJOR_VER_SHFT;
 888         mhi_cntrl->minor_version = (soc_info & SOC_HW_VERSION_MINOR_VER_BMSK) >>
 889                                         SOC_HW_VERSION_MINOR_VER_SHFT;
 890
 891         /* Register controller with MHI bus */
 892         mhi_dev = mhi_alloc_device(mhi_cntrl);
 893         if (IS_ERR(mhi_dev)) {
 894                 dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate MHI device\n");
 895                 ret = PTR_ERR(mhi_dev);
 896                 goto error_alloc_dev;
 897         }
 898
 899         mhi_dev->dev_type = MHI_DEVICE_CONTROLLER;
 900         mhi_dev->mhi_cntrl = mhi_cntrl;
 901         dev_set_name(&mhi_dev->dev, "%s", dev_name(mhi_cntrl->cntrl_dev));
 902
 903         /* Init wakeup source */
 904         device_init_wakeup(&mhi_dev->dev, true);
 905
 906         ret = device_add(&mhi_dev->dev);
 907         if (ret)
 908                 goto error_add_dev;
 909
 910         mhi_cntrl->mhi_dev = mhi_dev;
 911
 912         return 0;
 913
 914 error_add_dev:
 915         put_device(&mhi_dev->dev);
 916
 917 error_alloc_dev:
 918         kfree(mhi_cntrl->mhi_cmd);
 919
 920 error_alloc_cmd:
 921         vfree(mhi_cntrl->mhi_chan);
 922         kfree(mhi_cntrl->mhi_event);
 923
 924         return ret;
 925 }
 926 EXPORT_SYMBOL_GPL(mhi_register_controller);
 927
 928 void mhi_unregister_controller(struct mhi_controller *mhi_cntrl)
 929 {
 930         struct mhi_device *mhi_dev = mhi_cntrl->mhi_dev;
 931         struct mhi_chan *mhi_chan = mhi_cntrl->mhi_chan;
 932         unsigned int i;
 933
 934         kfree(mhi_cntrl->mhi_cmd);
 935         kfree(mhi_cntrl->mhi_event);
 936
 937         /* Drop the references to MHI devices created for channels */
 938         for (i = 0; i < mhi_cntrl->max_chan; i++, mhi_chan++) {
 939                 if (!mhi_chan->mhi_dev)
 940                         continue;
 941
 942                 put_device(&mhi_chan->mhi_dev->dev);
 943         }
 944         vfree(mhi_cntrl->mhi_chan);
 945
 946         device_del(&mhi_dev->dev);
 947         put_device(&mhi_dev->dev);
 948 }
 949 EXPORT_SYMBOL_GPL(mhi_unregister_controller);
 950
 951 int mhi_prepare_for_power_up(struct mhi_controller *mhi_cntrl)
 952 {
 953         struct device *dev = &mhi_cntrl->mhi_dev->dev;
 954         u32 bhie_off;
 955         int ret;
 956
 957         mutex_lock(&mhi_cntrl->pm_mutex);
 958
 959         ret = mhi_init_dev_ctxt(mhi_cntrl);
 960         if (ret)
 961                 goto error_dev_ctxt;
 962
 963         /*
 964          * Allocate RDDM table if specified, this table is for debugging purpose
 965          */
 966         if (mhi_cntrl->rddm_size) {
 967                 mhi_alloc_bhie_table(mhi_cntrl, &mhi_cntrl->rddm_image,
 968                                      mhi_cntrl->rddm_size);
 969
 970                 /*
 971                  * This controller supports RDDM, so we need to manually clear
 972                  * BHIE RX registers since POR values are undefined.
 973                  */
 974                 ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs, BHIEOFF,
 975                                    &bhie_off);
 976                 if (ret) {
 977                         dev_err(dev, "Error getting BHIE offset\n");
 978                         goto bhie_error;
 979                 }
 980
 981                 mhi_cntrl->bhie = mhi_cntrl->regs + bhie_off;
 982                 memset_io(mhi_cntrl->bhie + BHIE_RXVECADDR_LOW_OFFS,
 983                           0, BHIE_RXVECSTATUS_OFFS - BHIE_RXVECADDR_LOW_OFFS +
 984                           4);
 985
 986                 if (mhi_cntrl->rddm_image)
 987                         mhi_rddm_prepare(mhi_cntrl, mhi_cntrl->rddm_image);
 988         }
 989
 990         mhi_cntrl->pre_init = true;
 991
 992         mutex_unlock(&mhi_cntrl->pm_mutex);
 993
 994         return 0;
 995
 996 bhie_error:
 997         if (mhi_cntrl->rddm_image) {
 998                 mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->rddm_image);
 999                 mhi_cntrl->rddm_image = NULL;
1000         }
1001
1002 error_dev_ctxt:
1003         mutex_unlock(&mhi_cntrl->pm_mutex);
1004
1005         return ret;
1006 }
1007 EXPORT_SYMBOL_GPL(mhi_prepare_for_power_up);
1008
1009 void mhi_unprepare_after_power_down(struct mhi_controller *mhi_cntrl)
1010 {
1011         if (mhi_cntrl->fbc_image) {
1012                 mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->fbc_image);
1013                 mhi_cntrl->fbc_image = NULL;
1014         }
1015
1016         if (mhi_cntrl->rddm_image) {
1017                 mhi_free_bhie_table(mhi_cntrl, mhi_cntrl->rddm_image);
1018                 mhi_cntrl->rddm_image = NULL;
1019         }
1020
1021         mhi_deinit_dev_ctxt(mhi_cntrl);
1022         mhi_cntrl->pre_init = false;
1023 }
1024 EXPORT_SYMBOL_GPL(mhi_unprepare_after_power_down);
1025
1026 static void mhi_release_device(struct device *dev)
1027 {
1028         struct mhi_device *mhi_dev = to_mhi_device(dev);
1029
1030         /*
1031          * We need to set the mhi_chan->mhi_dev to NULL here since the MHI
1032          * devices for the channels will only get created if the mhi_dev
1033          * associated with it is NULL. This scenario will happen during the
1034          * controller suspend and resume.
1035          */
1036         if (mhi_dev->ul_chan)
1037                 mhi_dev->ul_chan->mhi_dev = NULL;
1038
1039         if (mhi_dev->dl_chan)
1040                 mhi_dev->dl_chan->mhi_dev = NULL;
1041
1042         kfree(mhi_dev);
1043 }
1044
1045 struct mhi_device *mhi_alloc_device(struct mhi_controller *mhi_cntrl)
1046 {
1047         struct mhi_device *mhi_dev;
1048         struct device *dev;
1049
1050         mhi_dev = kzalloc(sizeof(*mhi_dev), GFP_KERNEL);
1051         if (!mhi_dev)
1052                 return ERR_PTR(-ENOMEM);
1053
1054         dev = &mhi_dev->dev;
1055         device_initialize(dev);
1056         dev->bus = &mhi_bus_type;
1057         dev->release = mhi_release_device;
1058         dev->parent = mhi_cntrl->cntrl_dev;
1059         mhi_dev->mhi_cntrl = mhi_cntrl;
1060         mhi_dev->dev_wake = 0;
1061
1062         return mhi_dev;
1063 }
1064
1065 static int mhi_driver_probe(struct device *dev)
1066 {
1067         struct mhi_device *mhi_dev = to_mhi_device(dev);
1068         struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
1069         struct device_driver *drv = dev->driver;
1070         struct mhi_driver *mhi_drv = to_mhi_driver(drv);
1071         struct mhi_event *mhi_event;
1072         struct mhi_chan *ul_chan = mhi_dev->ul_chan;
1073         struct mhi_chan *dl_chan = mhi_dev->dl_chan;
1074         int ret;
1075
1076         /* Bring device out of LPM */
1077         ret = mhi_device_get_sync(mhi_dev);
1078         if (ret)
1079                 return ret;
1080
1081         ret = -EINVAL;
1082
1083         if (ul_chan) {
1084                 /*
1085                  * If channel supports LPM notifications then status_cb should
1086                  * be provided
1087                  */
1088                 if (ul_chan->lpm_notify && !mhi_drv->status_cb)
1089                         goto exit_probe;
1090
1091                 /* For non-offload channels then xfer_cb should be provided */
1092                 if (!ul_chan->offload_ch && !mhi_drv->ul_xfer_cb)
1093                         goto exit_probe;
1094
1095                 ul_chan->xfer_cb = mhi_drv->ul_xfer_cb;
1096                 if (ul_chan->auto_start) {
1097                         ret = mhi_prepare_channel(mhi_cntrl, ul_chan);
1098                         if (ret)
1099                                 goto exit_probe;
1100                 }
1101         }
1102
1103         if (dl_chan) {
1104                 /*
1105                  * If channel supports LPM notifications then status_cb should
1106                  * be provided
1107                  */
1108                 if (dl_chan->lpm_notify && !mhi_drv->status_cb)
1109                         goto exit_probe;
1110
1111                 /* For non-offload channels then xfer_cb should be provided */
1112                 if (!dl_chan->offload_ch && !mhi_drv->dl_xfer_cb)
1113                         goto exit_probe;
1114
1115                 mhi_event = &mhi_cntrl->mhi_event[dl_chan->er_index];
1116
1117                 /*
1118                  * If the channel event ring is managed by client, then
1119                  * status_cb must be provided so that the framework can
1120                  * notify pending data
1121                  */
1122                 if (mhi_event->cl_manage && !mhi_drv->status_cb)
1123                         goto exit_probe;
1124
1125                 dl_chan->xfer_cb = mhi_drv->dl_xfer_cb;
1126         }
1127
1128         /* Call the user provided probe function */
1129         ret = mhi_drv->probe(mhi_dev, mhi_dev->id);
1130         if (ret)
1131                 goto exit_probe;
1132
1133         if (dl_chan && dl_chan->auto_start)
1134                 mhi_prepare_channel(mhi_cntrl, dl_chan);
1135
1136         mhi_device_put(mhi_dev);
1137
1138         return ret;
1139
1140 exit_probe:
1141         mhi_unprepare_from_transfer(mhi_dev);
1142
1143         mhi_device_put(mhi_dev);
1144
1145         return ret;
1146 }
1147
1148 static int mhi_driver_remove(struct device *dev)
1149 {
1150         struct mhi_device *mhi_dev = to_mhi_device(dev);
1151         struct mhi_driver *mhi_drv = to_mhi_driver(dev->driver);
1152         struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
1153         struct mhi_chan *mhi_chan;
1154         enum mhi_ch_state ch_state[] = {
1155                 MHI_CH_STATE_DISABLED,
1156                 MHI_CH_STATE_DISABLED
1157         };
1158         int dir;
1159
1160         /* Skip if it is a controller device */
1161         if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER)
1162                 return 0;
1163
1164         /* Reset both channels */
1165         for (dir = 0; dir < 2; dir++) {
1166                 mhi_chan = dir ? mhi_dev->ul_chan : mhi_dev->dl_chan;
1167
1168                 if (!mhi_chan)
1169                         continue;
1170
1171                 /* Wake all threads waiting for completion */
1172                 write_lock_irq(&mhi_chan->lock);
1173                 mhi_chan->ccs = MHI_EV_CC_INVALID;
1174                 complete_all(&mhi_chan->completion);
1175                 write_unlock_irq(&mhi_chan->lock);
1176
1177                 /* Set the channel state to disabled */
1178                 mutex_lock(&mhi_chan->mutex);
1179                 write_lock_irq(&mhi_chan->lock);
1180                 ch_state[dir] = mhi_chan->ch_state;
1181                 mhi_chan->ch_state = MHI_CH_STATE_SUSPENDED;
1182                 write_unlock_irq(&mhi_chan->lock);
1183
1184                 /* Reset the non-offload channel */
1185                 if (!mhi_chan->offload_ch)
1186                         mhi_reset_chan(mhi_cntrl, mhi_chan);
1187
1188                 mutex_unlock(&mhi_chan->mutex);
1189         }
1190
1191         mhi_drv->remove(mhi_dev);
1192
1193         /* De-init channel if it was enabled */
1194         for (dir = 0; dir < 2; dir++) {
1195                 mhi_chan = dir ? mhi_dev->ul_chan : mhi_dev->dl_chan;
1196
1197                 if (!mhi_chan)
1198                         continue;
1199
1200                 mutex_lock(&mhi_chan->mutex);
1201
1202                 if (ch_state[dir] == MHI_CH_STATE_ENABLED &&
1203                     !mhi_chan->offload_ch)
1204                         mhi_deinit_chan_ctxt(mhi_cntrl, mhi_chan);
1205
1206                 mhi_chan->ch_state = MHI_CH_STATE_DISABLED;
1207
1208                 mutex_unlock(&mhi_chan->mutex);
1209         }
1210
1211         read_lock_bh(&mhi_cntrl->pm_lock);
1212         while (mhi_dev->dev_wake)
1213                 mhi_device_put(mhi_dev);
1214         read_unlock_bh(&mhi_cntrl->pm_lock);
1215
1216         return 0;
1217 }
1218
1219 int __mhi_driver_register(struct mhi_driver *mhi_drv, struct module *owner)
1220 {
1221         struct device_driver *driver = &mhi_drv->driver;
1222
1223         if (!mhi_drv->probe || !mhi_drv->remove)
1224                 return -EINVAL;
1225
1226         driver->bus = &mhi_bus_type;
1227         driver->owner = owner;
1228         driver->probe = mhi_driver_probe;
1229         driver->remove = mhi_driver_remove;
1230
1231         return driver_register(driver);
1232 }
1233 EXPORT_SYMBOL_GPL(__mhi_driver_register);
1234
1235 void mhi_driver_unregister(struct mhi_driver *mhi_drv)
1236 {
1237         driver_unregister(&mhi_drv->driver);
1238 }
1239 EXPORT_SYMBOL_GPL(mhi_driver_unregister);
1240
1241 static int mhi_uevent(struct device *dev, struct kobj_uevent_env *env)
1242 {
1243         struct mhi_device *mhi_dev = to_mhi_device(dev);
1244
1245         return add_uevent_var(env, "MODALIAS=" MHI_DEVICE_MODALIAS_FMT,
1246                                         mhi_dev->chan_name);
1247 }
1248
1249 static int mhi_match(struct device *dev, struct device_driver *drv)
1250 {
1251         struct mhi_device *mhi_dev = to_mhi_device(dev);
1252         struct mhi_driver *mhi_drv = to_mhi_driver(drv);
1253         const struct mhi_device_id *id;
1254
1255         /*
1256          * If the device is a controller type then there is no client driver
1257          * associated with it
1258          */
1259         if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER)
1260                 return 0;
1261
1262         for (id = mhi_drv->id_table; id->chan[0]; id++)
1263                 if (!strcmp(mhi_dev->chan_name, id->chan)) {
1264                         mhi_dev->id = id;
1265                         return 1;
1266                 }
1267
1268         return 0;
1269 };
1270
1271 struct bus_type mhi_bus_type = {
1272         .name = "mhi",
1273         .dev_name = "mhi",
1274         .match = mhi_match,
1275         .uevent = mhi_uevent,
1276 };
1277
1278 static int __init mhi_init(void)
1279 {
1280         return bus_register(&mhi_bus_type);
1281 }
1282
1283 static void __exit mhi_exit(void)
1284 {
1285         bus_unregister(&mhi_bus_type);
1286 }
1287
1288 postcore_initcall(mhi_init);
1289 module_exit(mhi_exit);
1290
1291 MODULE_LICENSE("GPL v2");
1292 MODULE_DESCRIPTION("MHI Host Interface");