drivers/i2c/busses/i2c-ismt.c

   1 /*
   2  * This file is provided under a dual BSD/GPLv2 license.  When using or
   3  * redistributing this file, you may do so under either license.
   4  *
   5  * Copyright(c) 2012 Intel Corporation. All rights reserved.
   6  *
   7  * GPL LICENSE SUMMARY
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of version 2 of the GNU General Public License as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  * The full GNU General Public License is included in this distribution
  18  * in the file called LICENSE.GPL.
  19  *
  20  * BSD LICENSE
  21  *
  22  * Redistribution and use in source and binary forms, with or without
  23  * modification, are permitted provided that the following conditions
  24  * are met:
  25  *
  26  *   * Redistributions of source code must retain the above copyright
  27  *     notice, this list of conditions and the following disclaimer.
  28  *   * Redistributions in binary form must reproduce the above copyright
  29  *     notice, this list of conditions and the following disclaimer in
  30  *     the documentation and/or other materials provided with the
  31  *     distribution.
  32  *   * Neither the name of Intel Corporation nor the names of its
  33  *     contributors may be used to endorse or promote products derived
  34  *     from this software without specific prior written permission.
  35  *
  36  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  37  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  38  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  39  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  40  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  42  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  43  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  44  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  45  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  46  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  47  */
  48
  49 /*
  50  *  Supports the SMBus Message Transport (SMT) in the Intel Atom Processor
  51  *  S12xx Product Family.
  52  *
  53  *  Features supported by this driver:
  54  *  Hardware PEC                     yes
  55  *  Block buffer                     yes
  56  *  Block process call transaction   no
  57  *  Slave mode                       no
  58  */
  59
  60 #include <linux/module.h>
  61 #include <linux/pci.h>
  62 #include <linux/kernel.h>
  63 #include <linux/stddef.h>
  64 #include <linux/completion.h>
  65 #include <linux/dma-mapping.h>
  66 #include <linux/i2c.h>
  67 #include <linux/acpi.h>
  68 #include <linux/interrupt.h>
  69
  70 #include <linux/io-64-nonatomic-lo-hi.h>
  71
  72 /* PCI Address Constants */
  73 #define SMBBAR          0
  74
  75 /* PCI DIDs for the Intel SMBus Message Transport (SMT) Devices */
  76 #define PCI_DEVICE_ID_INTEL_S1200_SMT0  0x0c59
  77 #define PCI_DEVICE_ID_INTEL_S1200_SMT1  0x0c5a
  78 #define PCI_DEVICE_ID_INTEL_AVOTON_SMT  0x1f15
  79
  80 #define ISMT_DESC_ENTRIES       2       /* number of descriptor entries */
  81 #define ISMT_MAX_RETRIES        3       /* number of SMBus retries to attempt */
  82
  83 /* Hardware Descriptor Constants - Control Field */
  84 #define ISMT_DESC_CWRL  0x01    /* Command/Write Length */
  85 #define ISMT_DESC_BLK   0X04    /* Perform Block Transaction */
  86 #define ISMT_DESC_FAIR  0x08    /* Set fairness flag upon successful arbit. */
  87 #define ISMT_DESC_PEC   0x10    /* Packet Error Code */
  88 #define ISMT_DESC_I2C   0x20    /* I2C Enable */
  89 #define ISMT_DESC_INT   0x40    /* Interrupt */
  90 #define ISMT_DESC_SOE   0x80    /* Stop On Error */
  91
  92 /* Hardware Descriptor Constants - Status Field */
  93 #define ISMT_DESC_SCS   0x01    /* Success */
  94 #define ISMT_DESC_DLTO  0x04    /* Data Low Time Out */
  95 #define ISMT_DESC_NAK   0x08    /* NAK Received */
  96 #define ISMT_DESC_CRC   0x10    /* CRC Error */
  97 #define ISMT_DESC_CLTO  0x20    /* Clock Low Time Out */
  98 #define ISMT_DESC_COL   0x40    /* Collisions */
  99 #define ISMT_DESC_LPR   0x80    /* Large Packet Received */
 100
 101 /* Macros */
 102 #define ISMT_DESC_ADDR_RW(addr, rw) (((addr) << 1) | (rw))
 103
 104 /* iSMT General Register address offsets (SMBBAR + <addr>) */
 105 #define ISMT_GR_GCTRL           0x000   /* General Control */
 106 #define ISMT_GR_SMTICL          0x008   /* SMT Interrupt Cause Location */
 107 #define ISMT_GR_ERRINTMSK       0x010   /* Error Interrupt Mask */
 108 #define ISMT_GR_ERRAERMSK       0x014   /* Error AER Mask */
 109 #define ISMT_GR_ERRSTS          0x018   /* Error Status */
 110 #define ISMT_GR_ERRINFO         0x01c   /* Error Information */
 111
 112 /* iSMT Master Registers */
 113 #define ISMT_MSTR_MDBA          0x100   /* Master Descriptor Base Address */
 114 #define ISMT_MSTR_MCTRL         0x108   /* Master Control */
 115 #define ISMT_MSTR_MSTS          0x10c   /* Master Status */
 116 #define ISMT_MSTR_MDS           0x110   /* Master Descriptor Size */
 117 #define ISMT_MSTR_RPOLICY       0x114   /* Retry Policy */
 118
 119 /* iSMT Miscellaneous Registers */
 120 #define ISMT_SPGT       0x300   /* SMBus PHY Global Timing */
 121
 122 /* General Control Register (GCTRL) bit definitions */
 123 #define ISMT_GCTRL_TRST 0x04    /* Target Reset */
 124 #define ISMT_GCTRL_KILL 0x08    /* Kill */
 125 #define ISMT_GCTRL_SRST 0x40    /* Soft Reset */
 126
 127 /* Master Control Register (MCTRL) bit definitions */
 128 #define ISMT_MCTRL_SS   0x01            /* Start/Stop */
 129 #define ISMT_MCTRL_MEIE 0x10            /* Master Error Interrupt Enable */
 130 #define ISMT_MCTRL_FMHP 0x00ff0000      /* Firmware Master Head Ptr (FMHP) */
 131
 132 /* Master Status Register (MSTS) bit definitions */
 133 #define ISMT_MSTS_HMTP  0xff0000        /* HW Master Tail Pointer (HMTP) */
 134 #define ISMT_MSTS_MIS   0x20            /* Master Interrupt Status (MIS) */
 135 #define ISMT_MSTS_MEIS  0x10            /* Master Error Int Status (MEIS) */
 136 #define ISMT_MSTS_IP    0x01            /* In Progress */
 137
 138 /* Master Descriptor Size (MDS) bit definitions */
 139 #define ISMT_MDS_MASK   0xff    /* Master Descriptor Size mask (MDS) */
 140
 141 /* SMBus PHY Global Timing Register (SPGT) bit definitions */
 142 #define ISMT_SPGT_SPD_MASK      0xc0000000      /* SMBus Speed mask */
 143 #define ISMT_SPGT_SPD_80K       0x00            /* 80 kHz */
 144 #define ISMT_SPGT_SPD_100K      (0x1 << 30)     /* 100 kHz */
 145 #define ISMT_SPGT_SPD_400K      (0x2 << 30)     /* 400 kHz */
 146 #define ISMT_SPGT_SPD_1M        (0x3 << 30)     /* 1 MHz */
 147
 148
 149 /* MSI Control Register (MSICTL) bit definitions */
 150 #define ISMT_MSICTL_MSIE        0x01    /* MSI Enable */
 151
 152 /* iSMT Hardware Descriptor */
 153 struct ismt_desc {
 154         u8 tgtaddr_rw;  /* target address & r/w bit */
 155         u8 wr_len_cmd;  /* write length in bytes or a command */
 156         u8 rd_len;      /* read length */
 157         u8 control;     /* control bits */
 158         u8 status;      /* status bits */
 159         u8 retry;       /* collision retry and retry count */
 160         u8 rxbytes;     /* received bytes */
 161         u8 txbytes;     /* transmitted bytes */
 162         u32 dptr_low;   /* lower 32 bit of the data pointer */
 163         u32 dptr_high;  /* upper 32 bit of the data pointer */
 164 } __packed;
 165
 166 struct ismt_priv {
 167         struct i2c_adapter adapter;
 168         void __iomem *smba;                     /* PCI BAR */
 169         struct pci_dev *pci_dev;
 170         struct ismt_desc *hw;                   /* descriptor virt base addr */
 171         dma_addr_t io_rng_dma;                  /* descriptor HW base addr */
 172         u8 head;                                /* ring buffer head pointer */
 173         struct completion cmp;                  /* interrupt completion */
 174         u8 dma_buffer[I2C_SMBUS_BLOCK_MAX + 1]; /* temp R/W data buffer */
 175 };
 176
 177 /**
 178  * ismt_ids - PCI device IDs supported by this driver
 179  */
 180 static const struct pci_device_id ismt_ids[] = {
 181         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT0) },
 182         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT1) },
 183         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_AVOTON_SMT) },
 184         { 0, }
 185 };
 186
 187 MODULE_DEVICE_TABLE(pci, ismt_ids);
 188
 189 /* Bus speed control bits for slow debuggers - refer to the docs for usage */
 190 static unsigned int bus_speed;
 191 module_param(bus_speed, uint, S_IRUGO);
 192 MODULE_PARM_DESC(bus_speed, "Bus Speed in kHz (0 = BIOS default)");
 193
 194 /**
 195  * __ismt_desc_dump() - dump the contents of a specific descriptor
 196  */
 197 static void __ismt_desc_dump(struct device *dev, const struct ismt_desc *desc)
 198 {
 199
 200         dev_dbg(dev, "Descriptor struct:  %p\n", desc);
 201         dev_dbg(dev, "\ttgtaddr_rw=0x%02X\n", desc->tgtaddr_rw);
 202         dev_dbg(dev, "\twr_len_cmd=0x%02X\n", desc->wr_len_cmd);
 203         dev_dbg(dev, "\trd_len=    0x%02X\n", desc->rd_len);
 204         dev_dbg(dev, "\tcontrol=   0x%02X\n", desc->control);
 205         dev_dbg(dev, "\tstatus=    0x%02X\n", desc->status);
 206         dev_dbg(dev, "\tretry=     0x%02X\n", desc->retry);
 207         dev_dbg(dev, "\trxbytes=   0x%02X\n", desc->rxbytes);
 208         dev_dbg(dev, "\ttxbytes=   0x%02X\n", desc->txbytes);
 209         dev_dbg(dev, "\tdptr_low=  0x%08X\n", desc->dptr_low);
 210         dev_dbg(dev, "\tdptr_high= 0x%08X\n", desc->dptr_high);
 211 }
 212 /**
 213  * ismt_desc_dump() - dump the contents of a descriptor for debug purposes
 214  * @priv: iSMT private data
 215  */
 216 static void ismt_desc_dump(struct ismt_priv *priv)
 217 {
 218         struct device *dev = &priv->pci_dev->dev;
 219         struct ismt_desc *desc = &priv->hw[priv->head];
 220
 221         dev_dbg(dev, "Dump of the descriptor struct:  0x%X\n", priv->head);
 222         __ismt_desc_dump(dev, desc);
 223 }
 224
 225 /**
 226  * ismt_gen_reg_dump() - dump the iSMT General Registers
 227  * @priv: iSMT private data
 228  */
 229 static void ismt_gen_reg_dump(struct ismt_priv *priv)
 230 {
 231         struct device *dev = &priv->pci_dev->dev;
 232
 233         dev_dbg(dev, "Dump of the iSMT General Registers\n");
 234         dev_dbg(dev, "  GCTRL.... : (0x%p)=0x%X\n",
 235                 priv->smba + ISMT_GR_GCTRL,
 236                 readl(priv->smba + ISMT_GR_GCTRL));
 237         dev_dbg(dev, "  SMTICL... : (0x%p)=0x%016llX\n",
 238                 priv->smba + ISMT_GR_SMTICL,
 239                 (long long unsigned int)readq(priv->smba + ISMT_GR_SMTICL));
 240         dev_dbg(dev, "  ERRINTMSK : (0x%p)=0x%X\n",
 241                 priv->smba + ISMT_GR_ERRINTMSK,
 242                 readl(priv->smba + ISMT_GR_ERRINTMSK));
 243         dev_dbg(dev, "  ERRAERMSK : (0x%p)=0x%X\n",
 244                 priv->smba + ISMT_GR_ERRAERMSK,
 245                 readl(priv->smba + ISMT_GR_ERRAERMSK));
 246         dev_dbg(dev, "  ERRSTS... : (0x%p)=0x%X\n",
 247                 priv->smba + ISMT_GR_ERRSTS,
 248                 readl(priv->smba + ISMT_GR_ERRSTS));
 249         dev_dbg(dev, "  ERRINFO.. : (0x%p)=0x%X\n",
 250                 priv->smba + ISMT_GR_ERRINFO,
 251                 readl(priv->smba + ISMT_GR_ERRINFO));
 252 }
 253
 254 /**
 255  * ismt_mstr_reg_dump() - dump the iSMT Master Registers
 256  * @priv: iSMT private data
 257  */
 258 static void ismt_mstr_reg_dump(struct ismt_priv *priv)
 259 {
 260         struct device *dev = &priv->pci_dev->dev;
 261
 262         dev_dbg(dev, "Dump of the iSMT Master Registers\n");
 263         dev_dbg(dev, "  MDBA..... : (0x%p)=0x%016llX\n",
 264                 priv->smba + ISMT_MSTR_MDBA,
 265                 (long long unsigned int)readq(priv->smba + ISMT_MSTR_MDBA));
 266         dev_dbg(dev, "  MCTRL.... : (0x%p)=0x%X\n",
 267                 priv->smba + ISMT_MSTR_MCTRL,
 268                 readl(priv->smba + ISMT_MSTR_MCTRL));
 269         dev_dbg(dev, "  MSTS..... : (0x%p)=0x%X\n",
 270                 priv->smba + ISMT_MSTR_MSTS,
 271                 readl(priv->smba + ISMT_MSTR_MSTS));
 272         dev_dbg(dev, "  MDS...... : (0x%p)=0x%X\n",
 273                 priv->smba + ISMT_MSTR_MDS,
 274                 readl(priv->smba + ISMT_MSTR_MDS));
 275         dev_dbg(dev, "  RPOLICY.. : (0x%p)=0x%X\n",
 276                 priv->smba + ISMT_MSTR_RPOLICY,
 277                 readl(priv->smba + ISMT_MSTR_RPOLICY));
 278         dev_dbg(dev, "  SPGT..... : (0x%p)=0x%X\n",
 279                 priv->smba + ISMT_SPGT,
 280                 readl(priv->smba + ISMT_SPGT));
 281 }
 282
 283 /**
 284  * ismt_submit_desc() - add a descriptor to the ring
 285  * @priv: iSMT private data
 286  */
 287 static void ismt_submit_desc(struct ismt_priv *priv)
 288 {
 289         uint fmhp;
 290         uint val;
 291
 292         ismt_desc_dump(priv);
 293         ismt_gen_reg_dump(priv);
 294         ismt_mstr_reg_dump(priv);
 295
 296         /* Set the FMHP (Firmware Master Head Pointer)*/
 297         fmhp = ((priv->head + 1) % ISMT_DESC_ENTRIES) << 16;
 298         val = readl(priv->smba + ISMT_MSTR_MCTRL);
 299         writel((val & ~ISMT_MCTRL_FMHP) | fmhp,
 300                priv->smba + ISMT_MSTR_MCTRL);
 301
 302         /* Set the start bit */
 303         val = readl(priv->smba + ISMT_MSTR_MCTRL);
 304         writel(val | ISMT_MCTRL_SS,
 305                priv->smba + ISMT_MSTR_MCTRL);
 306 }
 307
 308 /**
 309  * ismt_process_desc() - handle the completion of the descriptor
 310  * @desc: the iSMT hardware descriptor
 311  * @data: data buffer from the upper layer
 312  * @priv: ismt_priv struct holding our dma buffer
 313  * @size: SMBus transaction type
 314  * @read_write: flag to indicate if this is a read or write
 315  */
 316 static int ismt_process_desc(const struct ismt_desc *desc,
 317                              union i2c_smbus_data *data,
 318                              struct ismt_priv *priv, int size,
 319                              char read_write)
 320 {
 321         u8 *dma_buffer = priv->dma_buffer;
 322
 323         dev_dbg(&priv->pci_dev->dev, "Processing completed descriptor\n");
 324         __ismt_desc_dump(&priv->pci_dev->dev, desc);
 325
 326         if (desc->status & ISMT_DESC_SCS) {
 327                 if (read_write == I2C_SMBUS_WRITE &&
 328                     size != I2C_SMBUS_PROC_CALL)
 329                         return 0;
 330
 331                 switch (size) {
 332                 case I2C_SMBUS_BYTE:
 333                 case I2C_SMBUS_BYTE_DATA:
 334                         data->byte = dma_buffer[0];
 335                         break;
 336                 case I2C_SMBUS_WORD_DATA:
 337                 case I2C_SMBUS_PROC_CALL:
 338                         data->word = dma_buffer[0] | (dma_buffer[1] << 8);
 339                         break;
 340                 case I2C_SMBUS_BLOCK_DATA:
 341                         if (desc->rxbytes != dma_buffer[0] + 1)
 342                                 return -EMSGSIZE;
 343
 344                         memcpy(data->block, dma_buffer, desc->rxbytes);
 345                         break;
 346                 case I2C_SMBUS_I2C_BLOCK_DATA:
 347                         memcpy(&data->block[1], dma_buffer, desc->rxbytes);
 348                         data->block[0] = desc->rxbytes;
 349                         break;
 350                 }
 351                 return 0;
 352         }
 353
 354         if (likely(desc->status & ISMT_DESC_NAK))
 355                 return -ENXIO;
 356
 357         if (desc->status & ISMT_DESC_CRC)
 358                 return -EBADMSG;
 359
 360         if (desc->status & ISMT_DESC_COL)
 361                 return -EAGAIN;
 362
 363         if (desc->status & ISMT_DESC_LPR)
 364                 return -EPROTO;
 365
 366         if (desc->status & (ISMT_DESC_DLTO | ISMT_DESC_CLTO))
 367                 return -ETIMEDOUT;
 368
 369         return -EIO;
 370 }
 371
 372 /**
 373  * ismt_access() - process an SMBus command
 374  * @adap: the i2c host adapter
 375  * @addr: address of the i2c/SMBus target
 376  * @flags: command options
 377  * @read_write: read from or write to device
 378  * @command: the i2c/SMBus command to issue
 379  * @size: SMBus transaction type
 380  * @data: read/write data buffer
 381  */
 382 static int ismt_access(struct i2c_adapter *adap, u16 addr,
 383                        unsigned short flags, char read_write, u8 command,
 384                        int size, union i2c_smbus_data *data)
 385 {
 386         int ret;
 387         unsigned long time_left;
 388         dma_addr_t dma_addr = 0; /* address of the data buffer */
 389         u8 dma_size = 0;
 390         enum dma_data_direction dma_direction = 0;
 391         struct ismt_desc *desc;
 392         struct ismt_priv *priv = i2c_get_adapdata(adap);
 393         struct device *dev = &priv->pci_dev->dev;
 394
 395         desc = &priv->hw[priv->head];
 396
 397         /* Initialize the DMA buffer */
 398         memset(priv->dma_buffer, 0, sizeof(priv->dma_buffer));
 399
 400         /* Initialize the descriptor */
 401         memset(desc, 0, sizeof(struct ismt_desc));
 402         desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, read_write);
 403
 404         /* Initialize common control bits */
 405         if (likely(pci_dev_msi_enabled(priv->pci_dev)))
 406                 desc->control = ISMT_DESC_INT | ISMT_DESC_FAIR;
 407         else
 408                 desc->control = ISMT_DESC_FAIR;
 409
 410         if ((flags & I2C_CLIENT_PEC) && (size != I2C_SMBUS_QUICK)
 411             && (size != I2C_SMBUS_I2C_BLOCK_DATA))
 412                 desc->control |= ISMT_DESC_PEC;
 413
 414         switch (size) {
 415         case I2C_SMBUS_QUICK:
 416                 dev_dbg(dev, "I2C_SMBUS_QUICK\n");
 417                 break;
 418
 419         case I2C_SMBUS_BYTE:
 420                 if (read_write == I2C_SMBUS_WRITE) {
 421                         /*
 422                          * Send Byte
 423                          * The command field contains the write data
 424                          */
 425                         dev_dbg(dev, "I2C_SMBUS_BYTE:  WRITE\n");
 426                         desc->control |= ISMT_DESC_CWRL;
 427                         desc->wr_len_cmd = command;
 428                 } else {
 429                         /* Receive Byte */
 430                         dev_dbg(dev, "I2C_SMBUS_BYTE:  READ\n");
 431                         dma_size = 1;
 432                         dma_direction = DMA_FROM_DEVICE;
 433                         desc->rd_len = 1;
 434                 }
 435                 break;
 436
 437         case I2C_SMBUS_BYTE_DATA:
 438                 if (read_write == I2C_SMBUS_WRITE) {
 439                         /*
 440                          * Write Byte
 441                          * Command plus 1 data byte
 442                          */
 443                         dev_dbg(dev, "I2C_SMBUS_BYTE_DATA:  WRITE\n");
 444                         desc->wr_len_cmd = 2;
 445                         dma_size = 2;
 446                         dma_direction = DMA_TO_DEVICE;
 447                         priv->dma_buffer[0] = command;
 448                         priv->dma_buffer[1] = data->byte;
 449                 } else {
 450                         /* Read Byte */
 451                         dev_dbg(dev, "I2C_SMBUS_BYTE_DATA:  READ\n");
 452                         desc->control |= ISMT_DESC_CWRL;
 453                         desc->wr_len_cmd = command;
 454                         desc->rd_len = 1;
 455                         dma_size = 1;
 456                         dma_direction = DMA_FROM_DEVICE;
 457                 }
 458                 break;
 459
 460         case I2C_SMBUS_WORD_DATA:
 461                 if (read_write == I2C_SMBUS_WRITE) {
 462                         /* Write Word */
 463                         dev_dbg(dev, "I2C_SMBUS_WORD_DATA:  WRITE\n");
 464                         desc->wr_len_cmd = 3;
 465                         dma_size = 3;
 466                         dma_direction = DMA_TO_DEVICE;
 467                         priv->dma_buffer[0] = command;
 468                         priv->dma_buffer[1] = data->word & 0xff;
 469                         priv->dma_buffer[2] = data->word >> 8;
 470                 } else {
 471                         /* Read Word */
 472                         dev_dbg(dev, "I2C_SMBUS_WORD_DATA:  READ\n");
 473                         desc->wr_len_cmd = command;
 474                         desc->control |= ISMT_DESC_CWRL;
 475                         desc->rd_len = 2;
 476                         dma_size = 2;
 477                         dma_direction = DMA_FROM_DEVICE;
 478                 }
 479                 break;
 480
 481         case I2C_SMBUS_PROC_CALL:
 482                 dev_dbg(dev, "I2C_SMBUS_PROC_CALL\n");
 483                 desc->wr_len_cmd = 3;
 484                 desc->rd_len = 2;
 485                 dma_size = 3;
 486                 dma_direction = DMA_BIDIRECTIONAL;
 487                 priv->dma_buffer[0] = command;
 488                 priv->dma_buffer[1] = data->word & 0xff;
 489                 priv->dma_buffer[2] = data->word >> 8;
 490                 break;
 491
 492         case I2C_SMBUS_BLOCK_DATA:
 493                 if (read_write == I2C_SMBUS_WRITE) {
 494                         /* Block Write */
 495                         dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA:  WRITE\n");
 496                         dma_size = data->block[0] + 1;
 497                         dma_direction = DMA_TO_DEVICE;
 498                         desc->wr_len_cmd = dma_size;
 499                         desc->control |= ISMT_DESC_BLK;
 500                         priv->dma_buffer[0] = command;
 501                         memcpy(&priv->dma_buffer[1], &data->block[1], dma_size - 1);
 502                 } else {
 503                         /* Block Read */
 504                         dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA:  READ\n");
 505                         dma_size = I2C_SMBUS_BLOCK_MAX;
 506                         dma_direction = DMA_FROM_DEVICE;
 507                         desc->rd_len = dma_size;
 508                         desc->wr_len_cmd = command;
 509                         desc->control |= (ISMT_DESC_BLK | ISMT_DESC_CWRL);
 510                 }
 511                 break;
 512
 513         case I2C_SMBUS_I2C_BLOCK_DATA:
 514                 /* Make sure the length is valid */
 515                 if (data->block[0] < 1)
 516                         data->block[0] = 1;
 517
 518                 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
 519                         data->block[0] = I2C_SMBUS_BLOCK_MAX;
 520
 521                 if (read_write == I2C_SMBUS_WRITE) {
 522                         /* i2c Block Write */
 523                         dev_dbg(dev, "I2C_SMBUS_I2C_BLOCK_DATA:  WRITE\n");
 524                         dma_size = data->block[0] + 1;
 525                         dma_direction = DMA_TO_DEVICE;
 526                         desc->wr_len_cmd = dma_size;
 527                         desc->control |= ISMT_DESC_I2C;
 528                         priv->dma_buffer[0] = command;
 529                         memcpy(&priv->dma_buffer[1], &data->block[1], dma_size - 1);
 530                 } else {
 531                         /* i2c Block Read */
 532                         dev_dbg(dev, "I2C_SMBUS_I2C_BLOCK_DATA:  READ\n");
 533                         dma_size = data->block[0];
 534                         dma_direction = DMA_FROM_DEVICE;
 535                         desc->rd_len = dma_size;
 536                         desc->wr_len_cmd = command;
 537                         desc->control |= (ISMT_DESC_I2C | ISMT_DESC_CWRL);
 538                         /*
 539                          * Per the "Table 15-15. I2C Commands",
 540                          * in the External Design Specification (EDS),
 541                          * (Document Number: 508084, Revision: 2.0),
 542                          * the _rw bit must be 0
 543                          */
 544                         desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, 0);
 545                 }
 546                 break;
 547
 548         default:
 549                 dev_err(dev, "Unsupported transaction %d\n",
 550                         size);
 551                 return -EOPNOTSUPP;
 552         }
 553
 554         /* map the data buffer */
 555         if (dma_size != 0) {
 556                 dev_dbg(dev, " dev=%p\n", dev);
 557                 dev_dbg(dev, " data=%p\n", data);
 558                 dev_dbg(dev, " dma_buffer=%p\n", priv->dma_buffer);
 559                 dev_dbg(dev, " dma_size=%d\n", dma_size);
 560                 dev_dbg(dev, " dma_direction=%d\n", dma_direction);
 561
 562                 dma_addr = dma_map_single(dev,
 563                                       priv->dma_buffer,
 564                                       dma_size,
 565                                       dma_direction);
 566
 567                 if (dma_mapping_error(dev, dma_addr)) {
 568                         dev_err(dev, "Error in mapping dma buffer %p\n",
 569                                 priv->dma_buffer);
 570                         return -EIO;
 571                 }
 572
 573                 dev_dbg(dev, " dma_addr = 0x%016llX\n",
 574                         (unsigned long long)dma_addr);
 575
 576                 desc->dptr_low = lower_32_bits(dma_addr);
 577                 desc->dptr_high = upper_32_bits(dma_addr);
 578         }
 579
 580         reinit_completion(&priv->cmp);
 581
 582         /* Add the descriptor */
 583         ismt_submit_desc(priv);
 584
 585         /* Now we wait for interrupt completion, 1s */
 586         time_left = wait_for_completion_timeout(&priv->cmp, HZ*1);
 587
 588         /* unmap the data buffer */
 589         if (dma_size != 0)
 590                 dma_unmap_single(dev, dma_addr, dma_size, dma_direction);
 591
 592         if (unlikely(!time_left)) {
 593                 dev_err(dev, "completion wait timed out\n");
 594                 ret = -ETIMEDOUT;
 595                 goto out;
 596         }
 597
 598         /* do any post processing of the descriptor here */
 599         ret = ismt_process_desc(desc, data, priv, size, read_write);
 600
 601 out:
 602         /* Update the ring pointer */
 603         priv->head++;
 604         priv->head %= ISMT_DESC_ENTRIES;
 605
 606         return ret;
 607 }
 608
 609 /**
 610  * ismt_func() - report which i2c commands are supported by this adapter
 611  * @adap: the i2c host adapter
 612  */
 613 static u32 ismt_func(struct i2c_adapter *adap)
 614 {
 615         return I2C_FUNC_SMBUS_QUICK             |
 616                I2C_FUNC_SMBUS_BYTE              |
 617                I2C_FUNC_SMBUS_BYTE_DATA         |
 618                I2C_FUNC_SMBUS_WORD_DATA         |
 619                I2C_FUNC_SMBUS_PROC_CALL         |
 620                I2C_FUNC_SMBUS_BLOCK_DATA        |
 621                I2C_FUNC_SMBUS_I2C_BLOCK         |
 622                I2C_FUNC_SMBUS_PEC;
 623 }
 624
 625 /**
 626  * smbus_algorithm - the adapter algorithm and supported functionality
 627  * @smbus_xfer: the adapter algorithm
 628  * @functionality: functionality supported by the adapter
 629  */
 630 static const struct i2c_algorithm smbus_algorithm = {
 631         .smbus_xfer     = ismt_access,
 632         .functionality  = ismt_func,
 633 };
 634
 635 /**
 636  * ismt_handle_isr() - interrupt handler bottom half
 637  * @priv: iSMT private data
 638  */
 639 static irqreturn_t ismt_handle_isr(struct ismt_priv *priv)
 640 {
 641         complete(&priv->cmp);
 642
 643         return IRQ_HANDLED;
 644 }
 645
 646
 647 /**
 648  * ismt_do_interrupt() - IRQ interrupt handler
 649  * @vec: interrupt vector
 650  * @data: iSMT private data
 651  */
 652 static irqreturn_t ismt_do_interrupt(int vec, void *data)
 653 {
 654         u32 val;
 655         struct ismt_priv *priv = data;
 656
 657         /*
 658          * check to see it's our interrupt, return IRQ_NONE if not ours
 659          * since we are sharing interrupt
 660          */
 661         val = readl(priv->smba + ISMT_MSTR_MSTS);
 662
 663         if (!(val & (ISMT_MSTS_MIS | ISMT_MSTS_MEIS)))
 664                 return IRQ_NONE;
 665         else
 666                 writel(val | ISMT_MSTS_MIS | ISMT_MSTS_MEIS,
 667                        priv->smba + ISMT_MSTR_MSTS);
 668
 669         return ismt_handle_isr(priv);
 670 }
 671
 672 /**
 673  * ismt_do_msi_interrupt() - MSI interrupt handler
 674  * @vec: interrupt vector
 675  * @data: iSMT private data
 676  */
 677 static irqreturn_t ismt_do_msi_interrupt(int vec, void *data)
 678 {
 679         return ismt_handle_isr(data);
 680 }
 681
 682 /**
 683  * ismt_hw_init() - initialize the iSMT hardware
 684  * @priv: iSMT private data
 685  */
 686 static void ismt_hw_init(struct ismt_priv *priv)
 687 {
 688         u32 val;
 689         struct device *dev = &priv->pci_dev->dev;
 690
 691         /* initialize the Master Descriptor Base Address (MDBA) */
 692         writeq(priv->io_rng_dma, priv->smba + ISMT_MSTR_MDBA);
 693
 694         /* initialize the Master Control Register (MCTRL) */
 695         writel(ISMT_MCTRL_MEIE, priv->smba + ISMT_MSTR_MCTRL);
 696
 697         /* initialize the Master Status Register (MSTS) */
 698         writel(0, priv->smba + ISMT_MSTR_MSTS);
 699
 700         /* initialize the Master Descriptor Size (MDS) */
 701         val = readl(priv->smba + ISMT_MSTR_MDS);
 702         writel((val & ~ISMT_MDS_MASK) | (ISMT_DESC_ENTRIES - 1),
 703                 priv->smba + ISMT_MSTR_MDS);
 704
 705         /*
 706          * Set the SMBus speed (could use this for slow HW debuggers)
 707          */
 708
 709         val = readl(priv->smba + ISMT_SPGT);
 710
 711         switch (bus_speed) {
 712         case 0:
 713                 break;
 714
 715         case 80:
 716                 dev_dbg(dev, "Setting SMBus clock to 80 kHz\n");
 717                 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_80K),
 718                         priv->smba + ISMT_SPGT);
 719                 break;
 720
 721         case 100:
 722                 dev_dbg(dev, "Setting SMBus clock to 100 kHz\n");
 723                 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_100K),
 724                         priv->smba + ISMT_SPGT);
 725                 break;
 726
 727         case 400:
 728                 dev_dbg(dev, "Setting SMBus clock to 400 kHz\n");
 729                 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_400K),
 730                         priv->smba + ISMT_SPGT);
 731                 break;
 732
 733         case 1000:
 734                 dev_dbg(dev, "Setting SMBus clock to 1000 kHz\n");
 735                 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_1M),
 736                         priv->smba + ISMT_SPGT);
 737                 break;
 738
 739         default:
 740                 dev_warn(dev, "Invalid SMBus clock speed, only 0, 80, 100, 400, and 1000 are valid\n");
 741                 break;
 742         }
 743
 744         val = readl(priv->smba + ISMT_SPGT);
 745
 746         switch (val & ISMT_SPGT_SPD_MASK) {
 747         case ISMT_SPGT_SPD_80K:
 748                 bus_speed = 80;
 749                 break;
 750         case ISMT_SPGT_SPD_100K:
 751                 bus_speed = 100;
 752                 break;
 753         case ISMT_SPGT_SPD_400K:
 754                 bus_speed = 400;
 755                 break;
 756         case ISMT_SPGT_SPD_1M:
 757                 bus_speed = 1000;
 758                 break;
 759         }
 760         dev_dbg(dev, "SMBus clock is running at %d kHz\n", bus_speed);
 761 }
 762
 763 /**
 764  * ismt_dev_init() - initialize the iSMT data structures
 765  * @priv: iSMT private data
 766  */
 767 static int ismt_dev_init(struct ismt_priv *priv)
 768 {
 769         /* allocate memory for the descriptor */
 770         priv->hw = dmam_alloc_coherent(&priv->pci_dev->dev,
 771                                        (ISMT_DESC_ENTRIES
 772                                                * sizeof(struct ismt_desc)),
 773                                        &priv->io_rng_dma,
 774                                        GFP_KERNEL);
 775         if (!priv->hw)
 776                 return -ENOMEM;
 777
 778         memset(priv->hw, 0, (ISMT_DESC_ENTRIES * sizeof(struct ismt_desc)));
 779
 780         priv->head = 0;
 781         init_completion(&priv->cmp);
 782
 783         return 0;
 784 }
 785
 786 /**
 787  * ismt_int_init() - initialize interrupts
 788  * @priv: iSMT private data
 789  */
 790 static int ismt_int_init(struct ismt_priv *priv)
 791 {
 792         int err;
 793
 794         /* Try using MSI interrupts */
 795         err = pci_enable_msi(priv->pci_dev);
 796         if (err)
 797                 goto intx;
 798
 799         err = devm_request_irq(&priv->pci_dev->dev,
 800                                priv->pci_dev->irq,
 801                                ismt_do_msi_interrupt,
 802                                0,
 803                                "ismt-msi",
 804                                priv);
 805         if (err) {
 806                 pci_disable_msi(priv->pci_dev);
 807                 goto intx;
 808         }
 809
 810         return 0;
 811
 812         /* Try using legacy interrupts */
 813 intx:
 814         dev_warn(&priv->pci_dev->dev,
 815                  "Unable to use MSI interrupts, falling back to legacy\n");
 816
 817         err = devm_request_irq(&priv->pci_dev->dev,
 818                                priv->pci_dev->irq,
 819                                ismt_do_interrupt,
 820                                IRQF_SHARED,
 821                                "ismt-intx",
 822                                priv);
 823         if (err) {
 824                 dev_err(&priv->pci_dev->dev, "no usable interrupts\n");
 825                 return err;
 826         }
 827
 828         return 0;
 829 }
 830
 831 static struct pci_driver ismt_driver;
 832
 833 /**
 834  * ismt_probe() - probe for iSMT devices
 835  * @pdev: PCI-Express device
 836  * @id: PCI-Express device ID
 837  */
 838 static int
 839 ismt_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 840 {
 841         int err;
 842         struct ismt_priv *priv;
 843         unsigned long start, len;
 844
 845         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 846         if (!priv)
 847                 return -ENOMEM;
 848
 849         pci_set_drvdata(pdev, priv);
 850
 851         i2c_set_adapdata(&priv->adapter, priv);
 852         priv->adapter.owner = THIS_MODULE;
 853         priv->adapter.class = I2C_CLASS_HWMON;
 854         priv->adapter.algo = &smbus_algorithm;
 855         priv->adapter.dev.parent = &pdev->dev;
 856         ACPI_COMPANION_SET(&priv->adapter.dev, ACPI_COMPANION(&pdev->dev));
 857         priv->adapter.retries = ISMT_MAX_RETRIES;
 858
 859         priv->pci_dev = pdev;
 860
 861         err = pcim_enable_device(pdev);
 862         if (err) {
 863                 dev_err(&pdev->dev, "Failed to enable SMBus PCI device (%d)\n",
 864                         err);
 865                 return err;
 866         }
 867
 868         /* enable bus mastering */
 869         pci_set_master(pdev);
 870
 871         /* Determine the address of the SMBus area */
 872         start = pci_resource_start(pdev, SMBBAR);
 873         len = pci_resource_len(pdev, SMBBAR);
 874         if (!start || !len) {
 875                 dev_err(&pdev->dev,
 876                         "SMBus base address uninitialized, upgrade BIOS\n");
 877                 return -ENODEV;
 878         }
 879
 880         snprintf(priv->adapter.name, sizeof(priv->adapter.name),
 881                  "SMBus iSMT adapter at %lx", start);
 882
 883         dev_dbg(&priv->pci_dev->dev, " start=0x%lX\n", start);
 884         dev_dbg(&priv->pci_dev->dev, " len=0x%lX\n", len);
 885
 886         err = acpi_check_resource_conflict(&pdev->resource[SMBBAR]);
 887         if (err) {
 888                 dev_err(&pdev->dev, "ACPI resource conflict!\n");
 889                 return err;
 890         }
 891
 892         err = pci_request_region(pdev, SMBBAR, ismt_driver.name);
 893         if (err) {
 894                 dev_err(&pdev->dev,
 895                         "Failed to request SMBus region 0x%lx-0x%lx\n",
 896                         start, start + len);
 897                 return err;
 898         }
 899
 900         priv->smba = pcim_iomap(pdev, SMBBAR, len);
 901         if (!priv->smba) {
 902                 dev_err(&pdev->dev, "Unable to ioremap SMBus BAR\n");
 903                 return -ENODEV;
 904         }
 905
 906         if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(64)) != 0) ||
 907             (pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64)) != 0)) {
 908                 if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(32)) != 0) ||
 909                     (pci_set_consistent_dma_mask(pdev,
 910                                                  DMA_BIT_MASK(32)) != 0)) {
 911                         dev_err(&pdev->dev, "pci_set_dma_mask fail %p\n",
 912                                 pdev);
 913                         return -ENODEV;
 914                 }
 915         }
 916
 917         err = ismt_dev_init(priv);
 918         if (err)
 919                 return err;
 920
 921         ismt_hw_init(priv);
 922
 923         err = ismt_int_init(priv);
 924         if (err)
 925                 return err;
 926
 927         err = i2c_add_adapter(&priv->adapter);
 928         if (err) {
 929                 dev_err(&pdev->dev, "Failed to add SMBus iSMT adapter\n");
 930                 return -ENODEV;
 931         }
 932         return 0;
 933 }
 934
 935 /**
 936  * ismt_remove() - release driver resources
 937  * @pdev: PCI-Express device
 938  */
 939 static void ismt_remove(struct pci_dev *pdev)
 940 {
 941         struct ismt_priv *priv = pci_get_drvdata(pdev);
 942
 943         i2c_del_adapter(&priv->adapter);
 944 }
 945
 946 static struct pci_driver ismt_driver = {
 947         .name = "ismt_smbus",
 948         .id_table = ismt_ids,
 949         .probe = ismt_probe,
 950         .remove = ismt_remove,
 951 };
 952
 953 module_pci_driver(ismt_driver);
 954
 955 MODULE_LICENSE("Dual BSD/GPL");
 956 MODULE_AUTHOR("Bill E. Brown <bill.e.brown@intel.com>");
 957 MODULE_DESCRIPTION("Intel SMBus Message Transport (iSMT) driver");