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  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  21  * The full GNU General Public License is included in this distribution
  22  * in the file called LICENSE.GPL.
  23  *
  24  * BSD LICENSE
  25  *
  26  * Redistribution and use in source and binary forms, with or without
  27  * modification, are permitted provided that the following conditions
  28  * are met:
  29  *
  30  *   * Redistributions of source code must retain the above copyright
  31  *     notice, this list of conditions and the following disclaimer.
  32  *   * Redistributions in binary form must reproduce the above copyright
  33  *     notice, this list of conditions and the following disclaimer in
  34  *     the documentation and/or other materials provided with the
  35  *     distribution.
  36  *   * Neither the name of Intel Corporation nor the names of its
  37  *     contributors may be used to endorse or promote products derived
  38  *     from this software without specific prior written permission.
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  41  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  42  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  43  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  44  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  46  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  47  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  48  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  49  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  50  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  51  */
  52
  53 /*
  54  *  Supports the SMBus Message Transport (SMT) in the Intel Atom Processor
  55  *  S12xx Product Family.
  56  *
  57  *  Features supported by this driver:
  58  *  Hardware PEC                     yes
  59  *  Block buffer                     yes
  60  *  Block process call transaction   no
  61  *  Slave mode                       no
  62  */
  63
  64 #include <linux/module.h>
  65 #include <linux/pci.h>
  66 #include <linux/kernel.h>
  67 #include <linux/stddef.h>
  68 #include <linux/completion.h>
  69 #include <linux/dma-mapping.h>
  70 #include <linux/i2c.h>
  71 #include <linux/acpi.h>
  72 #include <linux/interrupt.h>
  73
  74 #include <asm-generic/io-64-nonatomic-lo-hi.h>
  75
  76 /* PCI Address Constants */
  77 #define SMBBAR          0
  78
  79 /* PCI DIDs for the Intel SMBus Message Transport (SMT) Devices */
  80 #define PCI_DEVICE_ID_INTEL_S1200_SMT0  0x0c59
  81 #define PCI_DEVICE_ID_INTEL_S1200_SMT1  0x0c5a
  82 #define PCI_DEVICE_ID_INTEL_AVOTON_SMT  0x1f15
  83
  84 #define ISMT_DESC_ENTRIES       32      /* number of descriptor entries */
  85 #define ISMT_MAX_RETRIES        3       /* number of SMBus retries to attempt */
  86
  87 /* Hardware Descriptor Constants - Control Field */
  88 #define ISMT_DESC_CWRL  0x01    /* Command/Write Length */
  89 #define ISMT_DESC_BLK   0X04    /* Perform Block Transaction */
  90 #define ISMT_DESC_FAIR  0x08    /* Set fairness flag upon successful arbit. */
  91 #define ISMT_DESC_PEC   0x10    /* Packet Error Code */
  92 #define ISMT_DESC_I2C   0x20    /* I2C Enable */
  93 #define ISMT_DESC_INT   0x40    /* Interrupt */
  94 #define ISMT_DESC_SOE   0x80    /* Stop On Error */
  95
  96 /* Hardware Descriptor Constants - Status Field */
  97 #define ISMT_DESC_SCS   0x01    /* Success */
  98 #define ISMT_DESC_DLTO  0x04    /* Data Low Time Out */
  99 #define ISMT_DESC_NAK   0x08    /* NAK Received */
 100 #define ISMT_DESC_CRC   0x10    /* CRC Error */
 101 #define ISMT_DESC_CLTO  0x20    /* Clock Low Time Out */
 102 #define ISMT_DESC_COL   0x40    /* Collisions */
 103 #define ISMT_DESC_LPR   0x80    /* Large Packet Received */
 104
 105 /* Macros */
 106 #define ISMT_DESC_ADDR_RW(addr, rw) (((addr) << 1) | (rw))
 107
 108 /* iSMT General Register address offsets (SMBBAR + <addr>) */
 109 #define ISMT_GR_GCTRL           0x000   /* General Control */
 110 #define ISMT_GR_SMTICL          0x008   /* SMT Interrupt Cause Location */
 111 #define ISMT_GR_ERRINTMSK       0x010   /* Error Interrupt Mask */
 112 #define ISMT_GR_ERRAERMSK       0x014   /* Error AER Mask */
 113 #define ISMT_GR_ERRSTS          0x018   /* Error Status */
 114 #define ISMT_GR_ERRINFO         0x01c   /* Error Information */
 115
 116 /* iSMT Master Registers */
 117 #define ISMT_MSTR_MDBA          0x100   /* Master Descriptor Base Address */
 118 #define ISMT_MSTR_MCTRL         0x108   /* Master Control */
 119 #define ISMT_MSTR_MSTS          0x10c   /* Master Status */
 120 #define ISMT_MSTR_MDS           0x110   /* Master Descriptor Size */
 121 #define ISMT_MSTR_RPOLICY       0x114   /* Retry Policy */
 122
 123 /* iSMT Miscellaneous Registers */
 124 #define ISMT_SPGT       0x300   /* SMBus PHY Global Timing */
 125
 126 /* General Control Register (GCTRL) bit definitions */
 127 #define ISMT_GCTRL_TRST 0x04    /* Target Reset */
 128 #define ISMT_GCTRL_KILL 0x08    /* Kill */
 129 #define ISMT_GCTRL_SRST 0x40    /* Soft Reset */
 130
 131 /* Master Control Register (MCTRL) bit definitions */
 132 #define ISMT_MCTRL_SS   0x01            /* Start/Stop */
 133 #define ISMT_MCTRL_MEIE 0x10            /* Master Error Interrupt Enable */
 134 #define ISMT_MCTRL_FMHP 0x00ff0000      /* Firmware Master Head Ptr (FMHP) */
 135
 136 /* Master Status Register (MSTS) bit definitions */
 137 #define ISMT_MSTS_HMTP  0xff0000        /* HW Master Tail Pointer (HMTP) */
 138 #define ISMT_MSTS_MIS   0x20            /* Master Interrupt Status (MIS) */
 139 #define ISMT_MSTS_MEIS  0x10            /* Master Error Int Status (MEIS) */
 140 #define ISMT_MSTS_IP    0x01            /* In Progress */
 141
 142 /* Master Descriptor Size (MDS) bit definitions */
 143 #define ISMT_MDS_MASK   0xff    /* Master Descriptor Size mask (MDS) */
 144
 145 /* SMBus PHY Global Timing Register (SPGT) bit definitions */
 146 #define ISMT_SPGT_SPD_MASK      0xc0000000      /* SMBus Speed mask */
 147 #define ISMT_SPGT_SPD_80K       0x00            /* 80 kHz */
 148 #define ISMT_SPGT_SPD_100K      (0x1 << 30)     /* 100 kHz */
 149 #define ISMT_SPGT_SPD_400K      (0x2 << 30)     /* 400 kHz */
 150 #define ISMT_SPGT_SPD_1M        (0x3 << 30)     /* 1 MHz */
 151
 152
 153 /* MSI Control Register (MSICTL) bit definitions */
 154 #define ISMT_MSICTL_MSIE        0x01    /* MSI Enable */
 155
 156 /* iSMT Hardware Descriptor */
 157 struct ismt_desc {
 158         u8 tgtaddr_rw;  /* target address & r/w bit */
 159         u8 wr_len_cmd;  /* write length in bytes or a command */
 160         u8 rd_len;      /* read length */
 161         u8 control;     /* control bits */
 162         u8 status;      /* status bits */
 163         u8 retry;       /* collision retry and retry count */
 164         u8 rxbytes;     /* received bytes */
 165         u8 txbytes;     /* transmitted bytes */
 166         u32 dptr_low;   /* lower 32 bit of the data pointer */
 167         u32 dptr_high;  /* upper 32 bit of the data pointer */
 168 } __packed;
 169
 170 struct ismt_priv {
 171         struct i2c_adapter adapter;
 172         void *smba;                             /* PCI BAR */
 173         struct pci_dev *pci_dev;
 174         struct ismt_desc *hw;                   /* descriptor virt base addr */
 175         dma_addr_t io_rng_dma;                  /* descriptor HW base addr */
 176         u8 head;                                /* ring buffer head pointer */
 177         struct completion cmp;                  /* interrupt completion */
 178         u8 dma_buffer[I2C_SMBUS_BLOCK_MAX + 1]; /* temp R/W data buffer */
 179         bool using_msi;                         /* type of interrupt flag */
 180 };
 181
 182 /**
 183  * ismt_ids - PCI device IDs supported by this driver
 184  */
 185 static DEFINE_PCI_DEVICE_TABLE(ismt_ids) = {
 186         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT0) },
 187         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT1) },
 188         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_AVOTON_SMT) },
 189         { 0, }
 190 };
 191
 192 MODULE_DEVICE_TABLE(pci, ismt_ids);
 193
 194 /* Bus speed control bits for slow debuggers - refer to the docs for usage */
 195 static unsigned int bus_speed;
 196 module_param(bus_speed, uint, S_IRUGO);
 197 MODULE_PARM_DESC(bus_speed, "Bus Speed in kHz (0 = BIOS default)");
 198
 199 /**
 200  * __ismt_desc_dump() - dump the contents of a specific descriptor
 201  */
 202 static void __ismt_desc_dump(struct device *dev, const struct ismt_desc *desc)
 203 {
 204
 205         dev_dbg(dev, "Descriptor struct:  %p\n", desc);
 206         dev_dbg(dev, "\ttgtaddr_rw=0x%02X\n", desc->tgtaddr_rw);
 207         dev_dbg(dev, "\twr_len_cmd=0x%02X\n", desc->wr_len_cmd);
 208         dev_dbg(dev, "\trd_len=    0x%02X\n", desc->rd_len);
 209         dev_dbg(dev, "\tcontrol=   0x%02X\n", desc->control);
 210         dev_dbg(dev, "\tstatus=    0x%02X\n", desc->status);
 211         dev_dbg(dev, "\tretry=     0x%02X\n", desc->retry);
 212         dev_dbg(dev, "\trxbytes=   0x%02X\n", desc->rxbytes);
 213         dev_dbg(dev, "\ttxbytes=   0x%02X\n", desc->txbytes);
 214         dev_dbg(dev, "\tdptr_low=  0x%08X\n", desc->dptr_low);
 215         dev_dbg(dev, "\tdptr_high= 0x%08X\n", desc->dptr_high);
 216 }
 217 /**
 218  * ismt_desc_dump() - dump the contents of a descriptor for debug purposes
 219  * @priv: iSMT private data
 220  */
 221 static void ismt_desc_dump(struct ismt_priv *priv)
 222 {
 223         struct device *dev = &priv->pci_dev->dev;
 224         struct ismt_desc *desc = &priv->hw[priv->head];
 225
 226         dev_dbg(dev, "Dump of the descriptor struct:  0x%X\n", priv->head);
 227         __ismt_desc_dump(dev, desc);
 228 }
 229
 230 /**
 231  * ismt_gen_reg_dump() - dump the iSMT General Registers
 232  * @priv: iSMT private data
 233  */
 234 static void ismt_gen_reg_dump(struct ismt_priv *priv)
 235 {
 236         struct device *dev = &priv->pci_dev->dev;
 237
 238         dev_dbg(dev, "Dump of the iSMT General Registers\n");
 239         dev_dbg(dev, "  GCTRL.... : (0x%p)=0x%X\n",
 240                 priv->smba + ISMT_GR_GCTRL,
 241                 readl(priv->smba + ISMT_GR_GCTRL));
 242         dev_dbg(dev, "  SMTICL... : (0x%p)=0x%016llX\n",
 243                 priv->smba + ISMT_GR_SMTICL,
 244                 (long long unsigned int)readq(priv->smba + ISMT_GR_SMTICL));
 245         dev_dbg(dev, "  ERRINTMSK : (0x%p)=0x%X\n",
 246                 priv->smba + ISMT_GR_ERRINTMSK,
 247                 readl(priv->smba + ISMT_GR_ERRINTMSK));
 248         dev_dbg(dev, "  ERRAERMSK : (0x%p)=0x%X\n",
 249                 priv->smba + ISMT_GR_ERRAERMSK,
 250                 readl(priv->smba + ISMT_GR_ERRAERMSK));
 251         dev_dbg(dev, "  ERRSTS... : (0x%p)=0x%X\n",
 252                 priv->smba + ISMT_GR_ERRSTS,
 253                 readl(priv->smba + ISMT_GR_ERRSTS));
 254         dev_dbg(dev, "  ERRINFO.. : (0x%p)=0x%X\n",
 255                 priv->smba + ISMT_GR_ERRINFO,
 256                 readl(priv->smba + ISMT_GR_ERRINFO));
 257 }
 258
 259 /**
 260  * ismt_mstr_reg_dump() - dump the iSMT Master Registers
 261  * @priv: iSMT private data
 262  */
 263 static void ismt_mstr_reg_dump(struct ismt_priv *priv)
 264 {
 265         struct device *dev = &priv->pci_dev->dev;
 266
 267         dev_dbg(dev, "Dump of the iSMT Master Registers\n");
 268         dev_dbg(dev, "  MDBA..... : (0x%p)=0x%016llX\n",
 269                 priv->smba + ISMT_MSTR_MDBA,
 270                 (long long unsigned int)readq(priv->smba + ISMT_MSTR_MDBA));
 271         dev_dbg(dev, "  MCTRL.... : (0x%p)=0x%X\n",
 272                 priv->smba + ISMT_MSTR_MCTRL,
 273                 readl(priv->smba + ISMT_MSTR_MCTRL));
 274         dev_dbg(dev, "  MSTS..... : (0x%p)=0x%X\n",
 275                 priv->smba + ISMT_MSTR_MSTS,
 276                 readl(priv->smba + ISMT_MSTR_MSTS));
 277         dev_dbg(dev, "  MDS...... : (0x%p)=0x%X\n",
 278                 priv->smba + ISMT_MSTR_MDS,
 279                 readl(priv->smba + ISMT_MSTR_MDS));
 280         dev_dbg(dev, "  RPOLICY.. : (0x%p)=0x%X\n",
 281                 priv->smba + ISMT_MSTR_RPOLICY,
 282                 readl(priv->smba + ISMT_MSTR_RPOLICY));
 283         dev_dbg(dev, "  SPGT..... : (0x%p)=0x%X\n",
 284                 priv->smba + ISMT_SPGT,
 285                 readl(priv->smba + ISMT_SPGT));
 286 }
 287
 288 /**
 289  * ismt_submit_desc() - add a descriptor to the ring
 290  * @priv: iSMT private data
 291  */
 292 static void ismt_submit_desc(struct ismt_priv *priv)
 293 {
 294         uint fmhp;
 295         uint val;
 296
 297         ismt_desc_dump(priv);
 298         ismt_gen_reg_dump(priv);
 299         ismt_mstr_reg_dump(priv);
 300
 301         /* Set the FMHP (Firmware Master Head Pointer)*/
 302         fmhp = ((priv->head + 1) % ISMT_DESC_ENTRIES) << 16;
 303         val = readl(priv->smba + ISMT_MSTR_MCTRL);
 304         writel((val & ~ISMT_MCTRL_FMHP) | fmhp,
 305                priv->smba + ISMT_MSTR_MCTRL);
 306
 307         /* Set the start bit */
 308         val = readl(priv->smba + ISMT_MSTR_MCTRL);
 309         writel(val | ISMT_MCTRL_SS,
 310                priv->smba + ISMT_MSTR_MCTRL);
 311 }
 312
 313 /**
 314  * ismt_process_desc() - handle the completion of the descriptor
 315  * @desc: the iSMT hardware descriptor
 316  * @data: data buffer from the upper layer
 317  * @priv: ismt_priv struct holding our dma buffer
 318  * @size: SMBus transaction type
 319  * @read_write: flag to indicate if this is a read or write
 320  */
 321 static int ismt_process_desc(const struct ismt_desc *desc,
 322                              union i2c_smbus_data *data,
 323                              struct ismt_priv *priv, int size,
 324                              char read_write)
 325 {
 326         u8 *dma_buffer = priv->dma_buffer;
 327
 328         dev_dbg(&priv->pci_dev->dev, "Processing completed descriptor\n");
 329         __ismt_desc_dump(&priv->pci_dev->dev, desc);
 330
 331         if (desc->status & ISMT_DESC_SCS) {
 332                 if (read_write == I2C_SMBUS_WRITE &&
 333                     size != I2C_SMBUS_PROC_CALL)
 334                         return 0;
 335
 336                 switch (size) {
 337                 case I2C_SMBUS_BYTE:
 338                 case I2C_SMBUS_BYTE_DATA:
 339                         data->byte = dma_buffer[0];
 340                         break;
 341                 case I2C_SMBUS_WORD_DATA:
 342                 case I2C_SMBUS_PROC_CALL:
 343                         data->word = dma_buffer[0] | (dma_buffer[1] << 8);
 344                         break;
 345                 case I2C_SMBUS_BLOCK_DATA:
 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         dma_addr_t dma_addr = 0; /* address of the data buffer */
 388         u8 dma_size = 0;
 389         enum dma_data_direction dma_direction = 0;
 390         struct ismt_desc *desc;
 391         struct ismt_priv *priv = i2c_get_adapdata(adap);
 392         struct device *dev = &priv->pci_dev->dev;
 393
 394         desc = &priv->hw[priv->head];
 395
 396         /* Initialize the DMA buffer */
 397         memset(priv->dma_buffer, 0, sizeof(priv->dma_buffer));
 398
 399         /* Initialize the descriptor */
 400         memset(desc, 0, sizeof(struct ismt_desc));
 401         desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, read_write);
 402
 403         /* Initialize common control bits */
 404         if (likely(priv->using_msi))
 405                 desc->control = ISMT_DESC_INT | ISMT_DESC_FAIR;
 406         else
 407                 desc->control = ISMT_DESC_FAIR;
 408
 409         if ((flags & I2C_CLIENT_PEC) && (size != I2C_SMBUS_QUICK)
 410             && (size != I2C_SMBUS_I2C_BLOCK_DATA))
 411                 desc->control |= ISMT_DESC_PEC;
 412
 413         switch (size) {
 414         case I2C_SMBUS_QUICK:
 415                 dev_dbg(dev, "I2C_SMBUS_QUICK\n");
 416                 break;
 417
 418         case I2C_SMBUS_BYTE:
 419                 if (read_write == I2C_SMBUS_WRITE) {
 420                         /*
 421                          * Send Byte
 422                          * The command field contains the write data
 423                          */
 424                         dev_dbg(dev, "I2C_SMBUS_BYTE:  WRITE\n");
 425                         desc->control |= ISMT_DESC_CWRL;
 426                         desc->wr_len_cmd = command;
 427                 } else {
 428                         /* Receive Byte */
 429                         dev_dbg(dev, "I2C_SMBUS_BYTE:  READ\n");
 430                         dma_size = 1;
 431                         dma_direction = DMA_FROM_DEVICE;
 432                         desc->rd_len = 1;
 433                 }
 434                 break;
 435
 436         case I2C_SMBUS_BYTE_DATA:
 437                 if (read_write == I2C_SMBUS_WRITE) {
 438                         /*
 439                          * Write Byte
 440                          * Command plus 1 data byte
 441                          */
 442                         dev_dbg(dev, "I2C_SMBUS_BYTE_DATA:  WRITE\n");
 443                         desc->wr_len_cmd = 2;
 444                         dma_size = 2;
 445                         dma_direction = DMA_TO_DEVICE;
 446                         priv->dma_buffer[0] = command;
 447                         priv->dma_buffer[1] = data->byte;
 448                 } else {
 449                         /* Read Byte */
 450                         dev_dbg(dev, "I2C_SMBUS_BYTE_DATA:  READ\n");
 451                         desc->control |= ISMT_DESC_CWRL;
 452                         desc->wr_len_cmd = command;
 453                         desc->rd_len = 1;
 454                         dma_size = 1;
 455                         dma_direction = DMA_FROM_DEVICE;
 456                 }
 457                 break;
 458
 459         case I2C_SMBUS_WORD_DATA:
 460                 if (read_write == I2C_SMBUS_WRITE) {
 461                         /* Write Word */
 462                         dev_dbg(dev, "I2C_SMBUS_WORD_DATA:  WRITE\n");
 463                         desc->wr_len_cmd = 3;
 464                         dma_size = 3;
 465                         dma_direction = DMA_TO_DEVICE;
 466                         priv->dma_buffer[0] = command;
 467                         priv->dma_buffer[1] = data->word & 0xff;
 468                         priv->dma_buffer[2] = data->word >> 8;
 469                 } else {
 470                         /* Read Word */
 471                         dev_dbg(dev, "I2C_SMBUS_WORD_DATA:  READ\n");
 472                         desc->wr_len_cmd = command;
 473                         desc->control |= ISMT_DESC_CWRL;
 474                         desc->rd_len = 2;
 475                         dma_size = 2;
 476                         dma_direction = DMA_FROM_DEVICE;
 477                 }
 478                 break;
 479
 480         case I2C_SMBUS_PROC_CALL:
 481                 dev_dbg(dev, "I2C_SMBUS_PROC_CALL\n");
 482                 desc->wr_len_cmd = 3;
 483                 desc->rd_len = 2;
 484                 dma_size = 3;
 485                 dma_direction = DMA_BIDIRECTIONAL;
 486                 priv->dma_buffer[0] = command;
 487                 priv->dma_buffer[1] = data->word & 0xff;
 488                 priv->dma_buffer[2] = data->word >> 8;
 489                 break;
 490
 491         case I2C_SMBUS_BLOCK_DATA:
 492                 if (read_write == I2C_SMBUS_WRITE) {
 493                         /* Block Write */
 494                         dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA:  WRITE\n");
 495                         dma_size = data->block[0] + 1;
 496                         dma_direction = DMA_TO_DEVICE;
 497                         desc->wr_len_cmd = dma_size;
 498                         desc->control |= ISMT_DESC_BLK;
 499                         priv->dma_buffer[0] = command;
 500                         memcpy(&priv->dma_buffer[1], &data->block[1], dma_size);
 501                 } else {
 502                         /* Block Read */
 503                         dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA:  READ\n");
 504                         dma_size = I2C_SMBUS_BLOCK_MAX;
 505                         dma_direction = DMA_FROM_DEVICE;
 506                         desc->rd_len = dma_size;
 507                         desc->wr_len_cmd = command;
 508                         desc->control |= (ISMT_DESC_BLK | ISMT_DESC_CWRL);
 509                 }
 510                 break;
 511
 512         case I2C_SMBUS_I2C_BLOCK_DATA:
 513                 /* Make sure the length is valid */
 514                 if (data->block[0] < 1)
 515                         data->block[0] = 1;
 516
 517                 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
 518                         data->block[0] = I2C_SMBUS_BLOCK_MAX;
 519
 520                 if (read_write == I2C_SMBUS_WRITE) {
 521                         /* i2c Block Write */
 522                         dev_dbg(dev, "I2C_SMBUS_I2C_BLOCK_DATA:  WRITE\n");
 523                         dma_size = data->block[0] + 1;
 524                         dma_direction = DMA_TO_DEVICE;
 525                         desc->wr_len_cmd = dma_size;
 526                         desc->control |= ISMT_DESC_I2C;
 527                         priv->dma_buffer[0] = command;
 528                         memcpy(&priv->dma_buffer[1], &data->block[1], dma_size);
 529                 } else {
 530                         /* i2c Block Read */
 531                         dev_dbg(dev, "I2C_SMBUS_I2C_BLOCK_DATA:  READ\n");
 532                         dma_size = data->block[0];
 533                         dma_direction = DMA_FROM_DEVICE;
 534                         desc->rd_len = dma_size;
 535                         desc->wr_len_cmd = command;
 536                         desc->control |= (ISMT_DESC_I2C | ISMT_DESC_CWRL);
 537                         /*
 538                          * Per the "Table 15-15. I2C Commands",
 539                          * in the External Design Specification (EDS),
 540                          * (Document Number: 508084, Revision: 2.0),
 541                          * the _rw bit must be 0
 542                          */
 543                         desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, 0);
 544                 }
 545                 break;
 546
 547         default:
 548                 dev_err(dev, "Unsupported transaction %d\n",
 549                         size);
 550                 return -EOPNOTSUPP;
 551         }
 552
 553         /* map the data buffer */
 554         if (dma_size != 0) {
 555                 dev_dbg(dev, " dev=%p\n", dev);
 556                 dev_dbg(dev, " data=%p\n", data);
 557                 dev_dbg(dev, " dma_buffer=%p\n", priv->dma_buffer);
 558                 dev_dbg(dev, " dma_size=%d\n", dma_size);
 559                 dev_dbg(dev, " dma_direction=%d\n", dma_direction);
 560
 561                 dma_addr = dma_map_single(dev,
 562                                       priv->dma_buffer,
 563                                       dma_size,
 564                                       dma_direction);
 565
 566                 if (dma_mapping_error(dev, dma_addr)) {
 567                         dev_err(dev, "Error in mapping dma buffer %p\n",
 568                                 priv->dma_buffer);
 569                         return -EIO;
 570                 }
 571
 572                 dev_dbg(dev, " dma_addr = 0x%016llX\n",
 573                         (unsigned long long)dma_addr);
 574
 575                 desc->dptr_low = lower_32_bits(dma_addr);
 576                 desc->dptr_high = upper_32_bits(dma_addr);
 577         }
 578
 579         reinit_completion(&priv->cmp);
 580
 581         /* Add the descriptor */
 582         ismt_submit_desc(priv);
 583
 584         /* Now we wait for interrupt completion, 1s */
 585         ret = wait_for_completion_timeout(&priv->cmp, HZ*1);
 586
 587         /* unmap the data buffer */
 588         if (dma_size != 0)
 589                 dma_unmap_single(&adap->dev, dma_addr, dma_size, dma_direction);
 590
 591         if (unlikely(!ret)) {
 592                 dev_err(dev, "completion wait timed out\n");
 593                 ret = -ETIMEDOUT;
 594                 goto out;
 595         }
 596
 597         /* do any post processing of the descriptor here */
 598         ret = ismt_process_desc(desc, data, priv, size, read_write);
 599
 600 out:
 601         /* Update the ring pointer */
 602         priv->head++;
 603         priv->head %= ISMT_DESC_ENTRIES;
 604
 605         return ret;
 606 }
 607
 608 /**
 609  * ismt_func() - report which i2c commands are supported by this adapter
 610  * @adap: the i2c host adapter
 611  */
 612 static u32 ismt_func(struct i2c_adapter *adap)
 613 {
 614         return I2C_FUNC_SMBUS_QUICK             |
 615                I2C_FUNC_SMBUS_BYTE              |
 616                I2C_FUNC_SMBUS_BYTE_DATA         |
 617                I2C_FUNC_SMBUS_WORD_DATA         |
 618                I2C_FUNC_SMBUS_PROC_CALL         |
 619                I2C_FUNC_SMBUS_BLOCK_DATA        |
 620                I2C_FUNC_SMBUS_I2C_BLOCK         |
 621                I2C_FUNC_SMBUS_PEC;
 622 }
 623
 624 /**
 625  * smbus_algorithm - the adapter algorithm and supported functionality
 626  * @smbus_xfer: the adapter algorithm
 627  * @functionality: functionality supported by the adapter
 628  */
 629 static const struct i2c_algorithm smbus_algorithm = {
 630         .smbus_xfer     = ismt_access,
 631         .functionality  = ismt_func,
 632 };
 633
 634 /**
 635  * ismt_handle_isr() - interrupt handler bottom half
 636  * @priv: iSMT private data
 637  */
 638 static irqreturn_t ismt_handle_isr(struct ismt_priv *priv)
 639 {
 640         complete(&priv->cmp);
 641
 642         return IRQ_HANDLED;
 643 }
 644
 645
 646 /**
 647  * ismt_do_interrupt() - IRQ interrupt handler
 648  * @vec: interrupt vector
 649  * @data: iSMT private data
 650  */
 651 static irqreturn_t ismt_do_interrupt(int vec, void *data)
 652 {
 653         u32 val;
 654         struct ismt_priv *priv = data;
 655
 656         /*
 657          * check to see it's our interrupt, return IRQ_NONE if not ours
 658          * since we are sharing interrupt
 659          */
 660         val = readl(priv->smba + ISMT_MSTR_MSTS);
 661
 662         if (!(val & (ISMT_MSTS_MIS | ISMT_MSTS_MEIS)))
 663                 return IRQ_NONE;
 664         else
 665                 writel(val | ISMT_MSTS_MIS | ISMT_MSTS_MEIS,
 666                        priv->smba + ISMT_MSTR_MSTS);
 667
 668         return ismt_handle_isr(priv);
 669 }
 670
 671 /**
 672  * ismt_do_msi_interrupt() - MSI interrupt handler
 673  * @vec: interrupt vector
 674  * @data: iSMT private data
 675  */
 676 static irqreturn_t ismt_do_msi_interrupt(int vec, void *data)
 677 {
 678         return ismt_handle_isr(data);
 679 }
 680
 681 /**
 682  * ismt_hw_init() - initialize the iSMT hardware
 683  * @priv: iSMT private data
 684  */
 685 static void ismt_hw_init(struct ismt_priv *priv)
 686 {
 687         u32 val;
 688         struct device *dev = &priv->pci_dev->dev;
 689
 690         /* initialize the Master Descriptor Base Address (MDBA) */
 691         writeq(priv->io_rng_dma, priv->smba + ISMT_MSTR_MDBA);
 692
 693         /* initialize the Master Control Register (MCTRL) */
 694         writel(ISMT_MCTRL_MEIE, priv->smba + ISMT_MSTR_MCTRL);
 695
 696         /* initialize the Master Status Register (MSTS) */
 697         writel(0, priv->smba + ISMT_MSTR_MSTS);
 698
 699         /* initialize the Master Descriptor Size (MDS) */
 700         val = readl(priv->smba + ISMT_MSTR_MDS);
 701         writel((val & ~ISMT_MDS_MASK) | (ISMT_DESC_ENTRIES - 1),
 702                 priv->smba + ISMT_MSTR_MDS);
 703
 704         /*
 705          * Set the SMBus speed (could use this for slow HW debuggers)
 706          */
 707
 708         val = readl(priv->smba + ISMT_SPGT);
 709
 710         switch (bus_speed) {
 711         case 0:
 712                 break;
 713
 714         case 80:
 715                 dev_dbg(dev, "Setting SMBus clock to 80 kHz\n");
 716                 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_80K),
 717                         priv->smba + ISMT_SPGT);
 718                 break;
 719
 720         case 100:
 721                 dev_dbg(dev, "Setting SMBus clock to 100 kHz\n");
 722                 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_100K),
 723                         priv->smba + ISMT_SPGT);
 724                 break;
 725
 726         case 400:
 727                 dev_dbg(dev, "Setting SMBus clock to 400 kHz\n");
 728                 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_400K),
 729                         priv->smba + ISMT_SPGT);
 730                 break;
 731
 732         case 1000:
 733                 dev_dbg(dev, "Setting SMBus clock to 1000 kHz\n");
 734                 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_1M),
 735                         priv->smba + ISMT_SPGT);
 736                 break;
 737
 738         default:
 739                 dev_warn(dev, "Invalid SMBus clock speed, only 0, 80, 100, 400, and 1000 are valid\n");
 740                 break;
 741         }
 742
 743         val = readl(priv->smba + ISMT_SPGT);
 744
 745         switch (val & ISMT_SPGT_SPD_MASK) {
 746         case ISMT_SPGT_SPD_80K:
 747                 bus_speed = 80;
 748                 break;
 749         case ISMT_SPGT_SPD_100K:
 750                 bus_speed = 100;
 751                 break;
 752         case ISMT_SPGT_SPD_400K:
 753                 bus_speed = 400;
 754                 break;
 755         case ISMT_SPGT_SPD_1M:
 756                 bus_speed = 1000;
 757                 break;
 758         }
 759         dev_dbg(dev, "SMBus clock is running at %d kHz\n", bus_speed);
 760 }
 761
 762 /**
 763  * ismt_dev_init() - initialize the iSMT data structures
 764  * @priv: iSMT private data
 765  */
 766 static int ismt_dev_init(struct ismt_priv *priv)
 767 {
 768         /* allocate memory for the descriptor */
 769         priv->hw = dmam_alloc_coherent(&priv->pci_dev->dev,
 770                                        (ISMT_DESC_ENTRIES
 771                                                * sizeof(struct ismt_desc)),
 772                                        &priv->io_rng_dma,
 773                                        GFP_KERNEL);
 774         if (!priv->hw)
 775                 return -ENOMEM;
 776
 777         memset(priv->hw, 0, (ISMT_DESC_ENTRIES * sizeof(struct ismt_desc)));
 778
 779         priv->head = 0;
 780         init_completion(&priv->cmp);
 781
 782         return 0;
 783 }
 784
 785 /**
 786  * ismt_int_init() - initialize interrupts
 787  * @priv: iSMT private data
 788  */
 789 static int ismt_int_init(struct ismt_priv *priv)
 790 {
 791         int err;
 792
 793         /* Try using MSI interrupts */
 794         err = pci_enable_msi(priv->pci_dev);
 795         if (err) {
 796                 dev_warn(&priv->pci_dev->dev,
 797                          "Unable to use MSI interrupts, falling back to legacy\n");
 798                 goto intx;
 799         }
 800
 801         err = devm_request_irq(&priv->pci_dev->dev,
 802                                priv->pci_dev->irq,
 803                                ismt_do_msi_interrupt,
 804                                0,
 805                                "ismt-msi",
 806                                priv);
 807         if (err) {
 808                 pci_disable_msi(priv->pci_dev);
 809                 goto intx;
 810         }
 811
 812         priv->using_msi = true;
 813         goto done;
 814
 815         /* Try using legacy interrupts */
 816 intx:
 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 -ENODEV;
 826         }
 827
 828         priv->using_msi = false;
 829
 830 done:
 831         return 0;
 832 }
 833
 834 static struct pci_driver ismt_driver;
 835
 836 /**
 837  * ismt_probe() - probe for iSMT devices
 838  * @pdev: PCI-Express device
 839  * @id: PCI-Express device ID
 840  */
 841 static int
 842 ismt_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 843 {
 844         int err;
 845         struct ismt_priv *priv;
 846         unsigned long start, len;
 847
 848         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 849         if (!priv)
 850                 return -ENOMEM;
 851
 852         pci_set_drvdata(pdev, priv);
 853         i2c_set_adapdata(&priv->adapter, priv);
 854         priv->adapter.owner = THIS_MODULE;
 855
 856         priv->adapter.class = I2C_CLASS_HWMON;
 857
 858         priv->adapter.algo = &smbus_algorithm;
 859
 860         /* set up the sysfs linkage to our parent device */
 861         priv->adapter.dev.parent = &pdev->dev;
 862
 863         /* number of retries on lost arbitration */
 864         priv->adapter.retries = ISMT_MAX_RETRIES;
 865
 866         priv->pci_dev = pdev;
 867
 868         err = pcim_enable_device(pdev);
 869         if (err) {
 870                 dev_err(&pdev->dev, "Failed to enable SMBus PCI device (%d)\n",
 871                         err);
 872                 return err;
 873         }
 874
 875         /* enable bus mastering */
 876         pci_set_master(pdev);
 877
 878         /* Determine the address of the SMBus area */
 879         start = pci_resource_start(pdev, SMBBAR);
 880         len = pci_resource_len(pdev, SMBBAR);
 881         if (!start || !len) {
 882                 dev_err(&pdev->dev,
 883                         "SMBus base address uninitialized, upgrade BIOS\n");
 884                 return -ENODEV;
 885         }
 886
 887         snprintf(priv->adapter.name, sizeof(priv->adapter.name),
 888                  "SMBus iSMT adapter at %lx", start);
 889
 890         dev_dbg(&priv->pci_dev->dev, " start=0x%lX\n", start);
 891         dev_dbg(&priv->pci_dev->dev, " len=0x%lX\n", len);
 892
 893         err = acpi_check_resource_conflict(&pdev->resource[SMBBAR]);
 894         if (err) {
 895                 dev_err(&pdev->dev, "ACPI resource conflict!\n");
 896                 return err;
 897         }
 898
 899         err = pci_request_region(pdev, SMBBAR, ismt_driver.name);
 900         if (err) {
 901                 dev_err(&pdev->dev,
 902                         "Failed to request SMBus region 0x%lx-0x%lx\n",
 903                         start, start + len);
 904                 return err;
 905         }
 906
 907         priv->smba = pcim_iomap(pdev, SMBBAR, len);
 908         if (!priv->smba) {
 909                 dev_err(&pdev->dev, "Unable to ioremap SMBus BAR\n");
 910                 err = -ENODEV;
 911                 goto fail;
 912         }
 913
 914         if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(64)) != 0) ||
 915             (pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64)) != 0)) {
 916                 if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(32)) != 0) ||
 917                     (pci_set_consistent_dma_mask(pdev,
 918                                                  DMA_BIT_MASK(32)) != 0)) {
 919                         dev_err(&pdev->dev, "pci_set_dma_mask fail %p\n",
 920                                 pdev);
 921                         err = -ENODEV;
 922                         goto fail;
 923                 }
 924         }
 925
 926         err = ismt_dev_init(priv);
 927         if (err)
 928                 goto fail;
 929
 930         ismt_hw_init(priv);
 931
 932         err = ismt_int_init(priv);
 933         if (err)
 934                 goto fail;
 935
 936         err = i2c_add_adapter(&priv->adapter);
 937         if (err) {
 938                 dev_err(&pdev->dev, "Failed to add SMBus iSMT adapter\n");
 939                 err = -ENODEV;
 940                 goto fail;
 941         }
 942         return 0;
 943
 944 fail:
 945         pci_release_region(pdev, SMBBAR);
 946         return err;
 947 }
 948
 949 /**
 950  * ismt_remove() - release driver resources
 951  * @pdev: PCI-Express device
 952  */
 953 static void ismt_remove(struct pci_dev *pdev)
 954 {
 955         struct ismt_priv *priv = pci_get_drvdata(pdev);
 956
 957         i2c_del_adapter(&priv->adapter);
 958         pci_release_region(pdev, SMBBAR);
 959 }
 960
 961 /**
 962  * ismt_suspend() - place the device in suspend
 963  * @pdev: PCI-Express device
 964  * @mesg: PM message
 965  */
 966 #ifdef CONFIG_PM
 967 static int ismt_suspend(struct pci_dev *pdev, pm_message_t mesg)
 968 {
 969         pci_save_state(pdev);
 970         pci_set_power_state(pdev, pci_choose_state(pdev, mesg));
 971         return 0;
 972 }
 973
 974 /**
 975  * ismt_resume() - PCI resume code
 976  * @pdev: PCI-Express device
 977  */
 978 static int ismt_resume(struct pci_dev *pdev)
 979 {
 980         pci_set_power_state(pdev, PCI_D0);
 981         pci_restore_state(pdev);
 982         return pci_enable_device(pdev);
 983 }
 984
 985 #else
 986
 987 #define ismt_suspend NULL
 988 #define ismt_resume NULL
 989
 990 #endif
 991
 992 static struct pci_driver ismt_driver = {
 993         .name = "ismt_smbus",
 994         .id_table = ismt_ids,
 995         .probe = ismt_probe,
 996         .remove = ismt_remove,
 997         .suspend = ismt_suspend,
 998         .resume = ismt_resume,
 999 };
1000
1001 module_pci_driver(ismt_driver);
1002
1003 MODULE_LICENSE("Dual BSD/GPL");
1004 MODULE_AUTHOR("Bill E. Brown <bill.e.brown@intel.com>");
1005 MODULE_DESCRIPTION("Intel SMBus Message Transport (iSMT) driver");