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/init.h>
  66 #include <linux/pci.h>
  67 #include <linux/kernel.h>
  68 #include <linux/stddef.h>
  69 #include <linux/completion.h>
  70 #include <linux/dma-mapping.h>
  71 #include <linux/i2c.h>
  72 #include <linux/acpi.h>
  73 #include <linux/interrupt.h>
  74
  75 #include <asm-generic/io-64-nonatomic-lo-hi.h>
  76
  77 /* PCI Address Constants */
  78 #define SMBBAR          0
  79
  80 /* PCI DIDs for the Intel SMBus Message Transport (SMT) Devices */
  81 #define PCI_DEVICE_ID_INTEL_S1200_SMT0  0x0c59
  82 #define PCI_DEVICE_ID_INTEL_S1200_SMT1  0x0c5a
  83 #define PCI_DEVICE_ID_INTEL_AVOTON_SMT  0x1f15
  84
  85 #define ISMT_DESC_ENTRIES       32      /* number of descriptor entries */
  86 #define ISMT_MAX_RETRIES        3       /* number of SMBus retries to attempt */
  87
  88 /* Hardware Descriptor Constants - Control Field */
  89 #define ISMT_DESC_CWRL  0x01    /* Command/Write Length */
  90 #define ISMT_DESC_BLK   0X04    /* Perform Block Transaction */
  91 #define ISMT_DESC_FAIR  0x08    /* Set fairness flag upon successful arbit. */
  92 #define ISMT_DESC_PEC   0x10    /* Packet Error Code */
  93 #define ISMT_DESC_I2C   0x20    /* I2C Enable */
  94 #define ISMT_DESC_INT   0x40    /* Interrupt */
  95 #define ISMT_DESC_SOE   0x80    /* Stop On Error */
  96
  97 /* Hardware Descriptor Constants - Status Field */
  98 #define ISMT_DESC_SCS   0x01    /* Success */
  99 #define ISMT_DESC_DLTO  0x04    /* Data Low Time Out */
 100 #define ISMT_DESC_NAK   0x08    /* NAK Received */
 101 #define ISMT_DESC_CRC   0x10    /* CRC Error */
 102 #define ISMT_DESC_CLTO  0x20    /* Clock Low Time Out */
 103 #define ISMT_DESC_COL   0x40    /* Collisions */
 104 #define ISMT_DESC_LPR   0x80    /* Large Packet Received */
 105
 106 /* Macros */
 107 #define ISMT_DESC_ADDR_RW(addr, rw) (((addr) << 1) | (rw))
 108
 109 /* iSMT General Register address offsets (SMBBAR + <addr>) */
 110 #define ISMT_GR_GCTRL           0x000   /* General Control */
 111 #define ISMT_GR_SMTICL          0x008   /* SMT Interrupt Cause Location */
 112 #define ISMT_GR_ERRINTMSK       0x010   /* Error Interrupt Mask */
 113 #define ISMT_GR_ERRAERMSK       0x014   /* Error AER Mask */
 114 #define ISMT_GR_ERRSTS          0x018   /* Error Status */
 115 #define ISMT_GR_ERRINFO         0x01c   /* Error Information */
 116
 117 /* iSMT Master Registers */
 118 #define ISMT_MSTR_MDBA          0x100   /* Master Descriptor Base Address */
 119 #define ISMT_MSTR_MCTRL         0x108   /* Master Control */
 120 #define ISMT_MSTR_MSTS          0x10c   /* Master Status */
 121 #define ISMT_MSTR_MDS           0x110   /* Master Descriptor Size */
 122 #define ISMT_MSTR_RPOLICY       0x114   /* Retry Policy */
 123
 124 /* iSMT Miscellaneous Registers */
 125 #define ISMT_SPGT       0x300   /* SMBus PHY Global Timing */
 126
 127 /* General Control Register (GCTRL) bit definitions */
 128 #define ISMT_GCTRL_TRST 0x04    /* Target Reset */
 129 #define ISMT_GCTRL_KILL 0x08    /* Kill */
 130 #define ISMT_GCTRL_SRST 0x40    /* Soft Reset */
 131
 132 /* Master Control Register (MCTRL) bit definitions */
 133 #define ISMT_MCTRL_SS   0x01            /* Start/Stop */
 134 #define ISMT_MCTRL_MEIE 0x10            /* Master Error Interrupt Enable */
 135 #define ISMT_MCTRL_FMHP 0x00ff0000      /* Firmware Master Head Ptr (FMHP) */
 136
 137 /* Master Status Register (MSTS) bit definitions */
 138 #define ISMT_MSTS_HMTP  0xff0000        /* HW Master Tail Pointer (HMTP) */
 139 #define ISMT_MSTS_MIS   0x20            /* Master Interrupt Status (MIS) */
 140 #define ISMT_MSTS_MEIS  0x10            /* Master Error Int Status (MEIS) */
 141 #define ISMT_MSTS_IP    0x01            /* In Progress */
 142
 143 /* Master Descriptor Size (MDS) bit definitions */
 144 #define ISMT_MDS_MASK   0xff    /* Master Descriptor Size mask (MDS) */
 145
 146 /* SMBus PHY Global Timing Register (SPGT) bit definitions */
 147 #define ISMT_SPGT_SPD_MASK      0xc0000000      /* SMBus Speed mask */
 148 #define ISMT_SPGT_SPD_80K       0x00            /* 80 kHz */
 149 #define ISMT_SPGT_SPD_100K      (0x1 << 30)     /* 100 kHz */
 150 #define ISMT_SPGT_SPD_400K      (0x2 << 30)     /* 400 kHz */
 151 #define ISMT_SPGT_SPD_1M        (0x3 << 30)     /* 1 MHz */
 152
 153
 154 /* MSI Control Register (MSICTL) bit definitions */
 155 #define ISMT_MSICTL_MSIE        0x01    /* MSI Enable */
 156
 157 /* iSMT Hardware Descriptor */
 158 struct ismt_desc {
 159         u8 tgtaddr_rw;  /* target address & r/w bit */
 160         u8 wr_len_cmd;  /* write length in bytes or a command */
 161         u8 rd_len;      /* read length */
 162         u8 control;     /* control bits */
 163         u8 status;      /* status bits */
 164         u8 retry;       /* collision retry and retry count */
 165         u8 rxbytes;     /* received bytes */
 166         u8 txbytes;     /* transmitted bytes */
 167         u32 dptr_low;   /* lower 32 bit of the data pointer */
 168         u32 dptr_high;  /* upper 32 bit of the data pointer */
 169 } __packed;
 170
 171 struct ismt_priv {
 172         struct i2c_adapter adapter;
 173         void *smba;                             /* PCI BAR */
 174         struct pci_dev *pci_dev;
 175         struct ismt_desc *hw;                   /* descriptor virt base addr */
 176         dma_addr_t io_rng_dma;                  /* descriptor HW base addr */
 177         u8 head;                                /* ring buffer head pointer */
 178         struct completion cmp;                  /* interrupt completion */
 179         u8 dma_buffer[I2C_SMBUS_BLOCK_MAX + 1]; /* temp R/W data buffer */
 180         bool using_msi;                         /* type of interrupt flag */
 181 };
 182
 183 /**
 184  * ismt_ids - PCI device IDs supported by this driver
 185  */
 186 static DEFINE_PCI_DEVICE_TABLE(ismt_ids) = {
 187         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT0) },
 188         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT1) },
 189         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_AVOTON_SMT) },
 190         { 0, }
 191 };
 192
 193 MODULE_DEVICE_TABLE(pci, ismt_ids);
 194
 195 /* Bus speed control bits for slow debuggers - refer to the docs for usage */
 196 static unsigned int bus_speed;
 197 module_param(bus_speed, uint, S_IRUGO);
 198 MODULE_PARM_DESC(bus_speed, "Bus Speed in kHz (0 = BIOS default)");
 199
 200 /**
 201  * __ismt_desc_dump() - dump the contents of a specific descriptor
 202  */
 203 static void __ismt_desc_dump(struct device *dev, const struct ismt_desc *desc)
 204 {
 205
 206         dev_dbg(dev, "Descriptor struct:  %p\n", desc);
 207         dev_dbg(dev, "\ttgtaddr_rw=0x%02X\n", desc->tgtaddr_rw);
 208         dev_dbg(dev, "\twr_len_cmd=0x%02X\n", desc->wr_len_cmd);
 209         dev_dbg(dev, "\trd_len=    0x%02X\n", desc->rd_len);
 210         dev_dbg(dev, "\tcontrol=   0x%02X\n", desc->control);
 211         dev_dbg(dev, "\tstatus=    0x%02X\n", desc->status);
 212         dev_dbg(dev, "\tretry=     0x%02X\n", desc->retry);
 213         dev_dbg(dev, "\trxbytes=   0x%02X\n", desc->rxbytes);
 214         dev_dbg(dev, "\ttxbytes=   0x%02X\n", desc->txbytes);
 215         dev_dbg(dev, "\tdptr_low=  0x%08X\n", desc->dptr_low);
 216         dev_dbg(dev, "\tdptr_high= 0x%08X\n", desc->dptr_high);
 217 }
 218 /**
 219  * ismt_desc_dump() - dump the contents of a descriptor for debug purposes
 220  * @priv: iSMT private data
 221  */
 222 static void ismt_desc_dump(struct ismt_priv *priv)
 223 {
 224         struct device *dev = &priv->pci_dev->dev;
 225         struct ismt_desc *desc = &priv->hw[priv->head];
 226
 227         dev_dbg(dev, "Dump of the descriptor struct:  0x%X\n", priv->head);
 228         __ismt_desc_dump(dev, desc);
 229 }
 230
 231 /**
 232  * ismt_gen_reg_dump() - dump the iSMT General Registers
 233  * @priv: iSMT private data
 234  */
 235 static void ismt_gen_reg_dump(struct ismt_priv *priv)
 236 {
 237         struct device *dev = &priv->pci_dev->dev;
 238
 239         dev_dbg(dev, "Dump of the iSMT General Registers\n");
 240         dev_dbg(dev, "  GCTRL.... : (0x%p)=0x%X\n",
 241                 priv->smba + ISMT_GR_GCTRL,
 242                 readl(priv->smba + ISMT_GR_GCTRL));
 243         dev_dbg(dev, "  SMTICL... : (0x%p)=0x%016llX\n",
 244                 priv->smba + ISMT_GR_SMTICL,
 245                 (long long unsigned int)readq(priv->smba + ISMT_GR_SMTICL));
 246         dev_dbg(dev, "  ERRINTMSK : (0x%p)=0x%X\n",
 247                 priv->smba + ISMT_GR_ERRINTMSK,
 248                 readl(priv->smba + ISMT_GR_ERRINTMSK));
 249         dev_dbg(dev, "  ERRAERMSK : (0x%p)=0x%X\n",
 250                 priv->smba + ISMT_GR_ERRAERMSK,
 251                 readl(priv->smba + ISMT_GR_ERRAERMSK));
 252         dev_dbg(dev, "  ERRSTS... : (0x%p)=0x%X\n",
 253                 priv->smba + ISMT_GR_ERRSTS,
 254                 readl(priv->smba + ISMT_GR_ERRSTS));
 255         dev_dbg(dev, "  ERRINFO.. : (0x%p)=0x%X\n",
 256                 priv->smba + ISMT_GR_ERRINFO,
 257                 readl(priv->smba + ISMT_GR_ERRINFO));
 258 }
 259
 260 /**
 261  * ismt_mstr_reg_dump() - dump the iSMT Master Registers
 262  * @priv: iSMT private data
 263  */
 264 static void ismt_mstr_reg_dump(struct ismt_priv *priv)
 265 {
 266         struct device *dev = &priv->pci_dev->dev;
 267
 268         dev_dbg(dev, "Dump of the iSMT Master Registers\n");
 269         dev_dbg(dev, "  MDBA..... : (0x%p)=0x%016llX\n",
 270                 priv->smba + ISMT_MSTR_MDBA,
 271                 (long long unsigned int)readq(priv->smba + ISMT_MSTR_MDBA));
 272         dev_dbg(dev, "  MCTRL.... : (0x%p)=0x%X\n",
 273                 priv->smba + ISMT_MSTR_MCTRL,
 274                 readl(priv->smba + ISMT_MSTR_MCTRL));
 275         dev_dbg(dev, "  MSTS..... : (0x%p)=0x%X\n",
 276                 priv->smba + ISMT_MSTR_MSTS,
 277                 readl(priv->smba + ISMT_MSTR_MSTS));
 278         dev_dbg(dev, "  MDS...... : (0x%p)=0x%X\n",
 279                 priv->smba + ISMT_MSTR_MDS,
 280                 readl(priv->smba + ISMT_MSTR_MDS));
 281         dev_dbg(dev, "  RPOLICY.. : (0x%p)=0x%X\n",
 282                 priv->smba + ISMT_MSTR_RPOLICY,
 283                 readl(priv->smba + ISMT_MSTR_RPOLICY));
 284         dev_dbg(dev, "  SPGT..... : (0x%p)=0x%X\n",
 285                 priv->smba + ISMT_SPGT,
 286                 readl(priv->smba + ISMT_SPGT));
 287 }
 288
 289 /**
 290  * ismt_submit_desc() - add a descriptor to the ring
 291  * @priv: iSMT private data
 292  */
 293 static void ismt_submit_desc(struct ismt_priv *priv)
 294 {
 295         uint fmhp;
 296         uint val;
 297
 298         ismt_desc_dump(priv);
 299         ismt_gen_reg_dump(priv);
 300         ismt_mstr_reg_dump(priv);
 301
 302         /* Set the FMHP (Firmware Master Head Pointer)*/
 303         fmhp = ((priv->head + 1) % ISMT_DESC_ENTRIES) << 16;
 304         val = readl(priv->smba + ISMT_MSTR_MCTRL);
 305         writel((val & ~ISMT_MCTRL_FMHP) | fmhp,
 306                priv->smba + ISMT_MSTR_MCTRL);
 307
 308         /* Set the start bit */
 309         val = readl(priv->smba + ISMT_MSTR_MCTRL);
 310         writel(val | ISMT_MCTRL_SS,
 311                priv->smba + ISMT_MSTR_MCTRL);
 312 }
 313
 314 /**
 315  * ismt_process_desc() - handle the completion of the descriptor
 316  * @desc: the iSMT hardware descriptor
 317  * @data: data buffer from the upper layer
 318  * @priv: ismt_priv struct holding our dma buffer
 319  * @size: SMBus transaction type
 320  * @read_write: flag to indicate if this is a read or write
 321  */
 322 static int ismt_process_desc(const struct ismt_desc *desc,
 323                              union i2c_smbus_data *data,
 324                              struct ismt_priv *priv, int size,
 325                              char read_write)
 326 {
 327         u8 *dma_buffer = priv->dma_buffer;
 328
 329         dev_dbg(&priv->pci_dev->dev, "Processing completed descriptor\n");
 330         __ismt_desc_dump(&priv->pci_dev->dev, desc);
 331
 332         if (desc->status & ISMT_DESC_SCS) {
 333                 if (read_write == I2C_SMBUS_WRITE &&
 334                     size != I2C_SMBUS_PROC_CALL)
 335                         return 0;
 336
 337                 switch (size) {
 338                 case I2C_SMBUS_BYTE:
 339                 case I2C_SMBUS_BYTE_DATA:
 340                         data->byte = dma_buffer[0];
 341                         break;
 342                 case I2C_SMBUS_WORD_DATA:
 343                 case I2C_SMBUS_PROC_CALL:
 344                         data->word = dma_buffer[0] | (dma_buffer[1] << 8);
 345                         break;
 346                 case I2C_SMBUS_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         default:
 513                 dev_err(dev, "Unsupported transaction %d\n",
 514                         size);
 515                 return -EOPNOTSUPP;
 516         }
 517
 518         /* map the data buffer */
 519         if (dma_size != 0) {
 520                 dev_dbg(dev, " dev=%p\n", dev);
 521                 dev_dbg(dev, " data=%p\n", data);
 522                 dev_dbg(dev, " dma_buffer=%p\n", priv->dma_buffer);
 523                 dev_dbg(dev, " dma_size=%d\n", dma_size);
 524                 dev_dbg(dev, " dma_direction=%d\n", dma_direction);
 525
 526                 dma_addr = dma_map_single(dev,
 527                                       priv->dma_buffer,
 528                                       dma_size,
 529                                       dma_direction);
 530
 531                 if (dma_mapping_error(dev, dma_addr)) {
 532                         dev_err(dev, "Error in mapping dma buffer %p\n",
 533                                 priv->dma_buffer);
 534                         return -EIO;
 535                 }
 536
 537                 dev_dbg(dev, " dma_addr = 0x%016llX\n",
 538                         (unsigned long long)dma_addr);
 539
 540                 desc->dptr_low = lower_32_bits(dma_addr);
 541                 desc->dptr_high = upper_32_bits(dma_addr);
 542         }
 543
 544         reinit_completion(&priv->cmp);
 545
 546         /* Add the descriptor */
 547         ismt_submit_desc(priv);
 548
 549         /* Now we wait for interrupt completion, 1s */
 550         ret = wait_for_completion_timeout(&priv->cmp, HZ*1);
 551
 552         /* unmap the data buffer */
 553         if (dma_size != 0)
 554                 dma_unmap_single(&adap->dev, dma_addr, dma_size, dma_direction);
 555
 556         if (unlikely(!ret)) {
 557                 dev_err(dev, "completion wait timed out\n");
 558                 ret = -ETIMEDOUT;
 559                 goto out;
 560         }
 561
 562         /* do any post processing of the descriptor here */
 563         ret = ismt_process_desc(desc, data, priv, size, read_write);
 564
 565 out:
 566         /* Update the ring pointer */
 567         priv->head++;
 568         priv->head %= ISMT_DESC_ENTRIES;
 569
 570         return ret;
 571 }
 572
 573 /**
 574  * ismt_func() - report which i2c commands are supported by this adapter
 575  * @adap: the i2c host adapter
 576  */
 577 static u32 ismt_func(struct i2c_adapter *adap)
 578 {
 579         return I2C_FUNC_SMBUS_QUICK             |
 580                I2C_FUNC_SMBUS_BYTE              |
 581                I2C_FUNC_SMBUS_BYTE_DATA         |
 582                I2C_FUNC_SMBUS_WORD_DATA         |
 583                I2C_FUNC_SMBUS_PROC_CALL         |
 584                I2C_FUNC_SMBUS_BLOCK_DATA        |
 585                I2C_FUNC_SMBUS_PEC;
 586 }
 587
 588 /**
 589  * smbus_algorithm - the adapter algorithm and supported functionality
 590  * @smbus_xfer: the adapter algorithm
 591  * @functionality: functionality supported by the adapter
 592  */
 593 static const struct i2c_algorithm smbus_algorithm = {
 594         .smbus_xfer     = ismt_access,
 595         .functionality  = ismt_func,
 596 };
 597
 598 /**
 599  * ismt_handle_isr() - interrupt handler bottom half
 600  * @priv: iSMT private data
 601  */
 602 static irqreturn_t ismt_handle_isr(struct ismt_priv *priv)
 603 {
 604         complete(&priv->cmp);
 605
 606         return IRQ_HANDLED;
 607 }
 608
 609
 610 /**
 611  * ismt_do_interrupt() - IRQ interrupt handler
 612  * @vec: interrupt vector
 613  * @data: iSMT private data
 614  */
 615 static irqreturn_t ismt_do_interrupt(int vec, void *data)
 616 {
 617         u32 val;
 618         struct ismt_priv *priv = data;
 619
 620         /*
 621          * check to see it's our interrupt, return IRQ_NONE if not ours
 622          * since we are sharing interrupt
 623          */
 624         val = readl(priv->smba + ISMT_MSTR_MSTS);
 625
 626         if (!(val & (ISMT_MSTS_MIS | ISMT_MSTS_MEIS)))
 627                 return IRQ_NONE;
 628         else
 629                 writel(val | ISMT_MSTS_MIS | ISMT_MSTS_MEIS,
 630                        priv->smba + ISMT_MSTR_MSTS);
 631
 632         return ismt_handle_isr(priv);
 633 }
 634
 635 /**
 636  * ismt_do_msi_interrupt() - MSI interrupt handler
 637  * @vec: interrupt vector
 638  * @data: iSMT private data
 639  */
 640 static irqreturn_t ismt_do_msi_interrupt(int vec, void *data)
 641 {
 642         return ismt_handle_isr(data);
 643 }
 644
 645 /**
 646  * ismt_hw_init() - initialize the iSMT hardware
 647  * @priv: iSMT private data
 648  */
 649 static void ismt_hw_init(struct ismt_priv *priv)
 650 {
 651         u32 val;
 652         struct device *dev = &priv->pci_dev->dev;
 653
 654         /* initialize the Master Descriptor Base Address (MDBA) */
 655         writeq(priv->io_rng_dma, priv->smba + ISMT_MSTR_MDBA);
 656
 657         /* initialize the Master Control Register (MCTRL) */
 658         writel(ISMT_MCTRL_MEIE, priv->smba + ISMT_MSTR_MCTRL);
 659
 660         /* initialize the Master Status Register (MSTS) */
 661         writel(0, priv->smba + ISMT_MSTR_MSTS);
 662
 663         /* initialize the Master Descriptor Size (MDS) */
 664         val = readl(priv->smba + ISMT_MSTR_MDS);
 665         writel((val & ~ISMT_MDS_MASK) | (ISMT_DESC_ENTRIES - 1),
 666                 priv->smba + ISMT_MSTR_MDS);
 667
 668         /*
 669          * Set the SMBus speed (could use this for slow HW debuggers)
 670          */
 671
 672         val = readl(priv->smba + ISMT_SPGT);
 673
 674         switch (bus_speed) {
 675         case 0:
 676                 break;
 677
 678         case 80:
 679                 dev_dbg(dev, "Setting SMBus clock to 80 kHz\n");
 680                 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_80K),
 681                         priv->smba + ISMT_SPGT);
 682                 break;
 683
 684         case 100:
 685                 dev_dbg(dev, "Setting SMBus clock to 100 kHz\n");
 686                 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_100K),
 687                         priv->smba + ISMT_SPGT);
 688                 break;
 689
 690         case 400:
 691                 dev_dbg(dev, "Setting SMBus clock to 400 kHz\n");
 692                 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_400K),
 693                         priv->smba + ISMT_SPGT);
 694                 break;
 695
 696         case 1000:
 697                 dev_dbg(dev, "Setting SMBus clock to 1000 kHz\n");
 698                 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_1M),
 699                         priv->smba + ISMT_SPGT);
 700                 break;
 701
 702         default:
 703                 dev_warn(dev, "Invalid SMBus clock speed, only 0, 80, 100, 400, and 1000 are valid\n");
 704                 break;
 705         }
 706
 707         val = readl(priv->smba + ISMT_SPGT);
 708
 709         switch (val & ISMT_SPGT_SPD_MASK) {
 710         case ISMT_SPGT_SPD_80K:
 711                 bus_speed = 80;
 712                 break;
 713         case ISMT_SPGT_SPD_100K:
 714                 bus_speed = 100;
 715                 break;
 716         case ISMT_SPGT_SPD_400K:
 717                 bus_speed = 400;
 718                 break;
 719         case ISMT_SPGT_SPD_1M:
 720                 bus_speed = 1000;
 721                 break;
 722         }
 723         dev_dbg(dev, "SMBus clock is running at %d kHz\n", bus_speed);
 724 }
 725
 726 /**
 727  * ismt_dev_init() - initialize the iSMT data structures
 728  * @priv: iSMT private data
 729  */
 730 static int ismt_dev_init(struct ismt_priv *priv)
 731 {
 732         /* allocate memory for the descriptor */
 733         priv->hw = dmam_alloc_coherent(&priv->pci_dev->dev,
 734                                        (ISMT_DESC_ENTRIES
 735                                                * sizeof(struct ismt_desc)),
 736                                        &priv->io_rng_dma,
 737                                        GFP_KERNEL);
 738         if (!priv->hw)
 739                 return -ENOMEM;
 740
 741         memset(priv->hw, 0, (ISMT_DESC_ENTRIES * sizeof(struct ismt_desc)));
 742
 743         priv->head = 0;
 744         init_completion(&priv->cmp);
 745
 746         return 0;
 747 }
 748
 749 /**
 750  * ismt_int_init() - initialize interrupts
 751  * @priv: iSMT private data
 752  */
 753 static int ismt_int_init(struct ismt_priv *priv)
 754 {
 755         int err;
 756
 757         /* Try using MSI interrupts */
 758         err = pci_enable_msi(priv->pci_dev);
 759         if (err) {
 760                 dev_warn(&priv->pci_dev->dev,
 761                          "Unable to use MSI interrupts, falling back to legacy\n");
 762                 goto intx;
 763         }
 764
 765         err = devm_request_irq(&priv->pci_dev->dev,
 766                                priv->pci_dev->irq,
 767                                ismt_do_msi_interrupt,
 768                                0,
 769                                "ismt-msi",
 770                                priv);
 771         if (err) {
 772                 pci_disable_msi(priv->pci_dev);
 773                 goto intx;
 774         }
 775
 776         priv->using_msi = true;
 777         goto done;
 778
 779         /* Try using legacy interrupts */
 780 intx:
 781         err = devm_request_irq(&priv->pci_dev->dev,
 782                                priv->pci_dev->irq,
 783                                ismt_do_interrupt,
 784                                IRQF_SHARED,
 785                                "ismt-intx",
 786                                priv);
 787         if (err) {
 788                 dev_err(&priv->pci_dev->dev, "no usable interrupts\n");
 789                 return -ENODEV;
 790         }
 791
 792         priv->using_msi = false;
 793
 794 done:
 795         return 0;
 796 }
 797
 798 static struct pci_driver ismt_driver;
 799
 800 /**
 801  * ismt_probe() - probe for iSMT devices
 802  * @pdev: PCI-Express device
 803  * @id: PCI-Express device ID
 804  */
 805 static int
 806 ismt_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 807 {
 808         int err;
 809         struct ismt_priv *priv;
 810         unsigned long start, len;
 811
 812         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 813         if (!priv)
 814                 return -ENOMEM;
 815
 816         pci_set_drvdata(pdev, priv);
 817         i2c_set_adapdata(&priv->adapter, priv);
 818         priv->adapter.owner = THIS_MODULE;
 819
 820         priv->adapter.class = I2C_CLASS_HWMON;
 821
 822         priv->adapter.algo = &smbus_algorithm;
 823
 824         /* set up the sysfs linkage to our parent device */
 825         priv->adapter.dev.parent = &pdev->dev;
 826
 827         /* number of retries on lost arbitration */
 828         priv->adapter.retries = ISMT_MAX_RETRIES;
 829
 830         priv->pci_dev = pdev;
 831
 832         err = pcim_enable_device(pdev);
 833         if (err) {
 834                 dev_err(&pdev->dev, "Failed to enable SMBus PCI device (%d)\n",
 835                         err);
 836                 return err;
 837         }
 838
 839         /* enable bus mastering */
 840         pci_set_master(pdev);
 841
 842         /* Determine the address of the SMBus area */
 843         start = pci_resource_start(pdev, SMBBAR);
 844         len = pci_resource_len(pdev, SMBBAR);
 845         if (!start || !len) {
 846                 dev_err(&pdev->dev,
 847                         "SMBus base address uninitialized, upgrade BIOS\n");
 848                 return -ENODEV;
 849         }
 850
 851         snprintf(priv->adapter.name, sizeof(priv->adapter.name),
 852                  "SMBus iSMT adapter at %lx", start);
 853
 854         dev_dbg(&priv->pci_dev->dev, " start=0x%lX\n", start);
 855         dev_dbg(&priv->pci_dev->dev, " len=0x%lX\n", len);
 856
 857         err = acpi_check_resource_conflict(&pdev->resource[SMBBAR]);
 858         if (err) {
 859                 dev_err(&pdev->dev, "ACPI resource conflict!\n");
 860                 return err;
 861         }
 862
 863         err = pci_request_region(pdev, SMBBAR, ismt_driver.name);
 864         if (err) {
 865                 dev_err(&pdev->dev,
 866                         "Failed to request SMBus region 0x%lx-0x%lx\n",
 867                         start, start + len);
 868                 return err;
 869         }
 870
 871         priv->smba = pcim_iomap(pdev, SMBBAR, len);
 872         if (!priv->smba) {
 873                 dev_err(&pdev->dev, "Unable to ioremap SMBus BAR\n");
 874                 err = -ENODEV;
 875                 goto fail;
 876         }
 877
 878         if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(64)) != 0) ||
 879             (pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64)) != 0)) {
 880                 if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(32)) != 0) ||
 881                     (pci_set_consistent_dma_mask(pdev,
 882                                                  DMA_BIT_MASK(32)) != 0)) {
 883                         dev_err(&pdev->dev, "pci_set_dma_mask fail %p\n",
 884                                 pdev);
 885                         err = -ENODEV;
 886                         goto fail;
 887                 }
 888         }
 889
 890         err = ismt_dev_init(priv);
 891         if (err)
 892                 goto fail;
 893
 894         ismt_hw_init(priv);
 895
 896         err = ismt_int_init(priv);
 897         if (err)
 898                 goto fail;
 899
 900         err = i2c_add_adapter(&priv->adapter);
 901         if (err) {
 902                 dev_err(&pdev->dev, "Failed to add SMBus iSMT adapter\n");
 903                 err = -ENODEV;
 904                 goto fail;
 905         }
 906         return 0;
 907
 908 fail:
 909         pci_release_region(pdev, SMBBAR);
 910         return err;
 911 }
 912
 913 /**
 914  * ismt_remove() - release driver resources
 915  * @pdev: PCI-Express device
 916  */
 917 static void ismt_remove(struct pci_dev *pdev)
 918 {
 919         struct ismt_priv *priv = pci_get_drvdata(pdev);
 920
 921         i2c_del_adapter(&priv->adapter);
 922         pci_release_region(pdev, SMBBAR);
 923 }
 924
 925 /**
 926  * ismt_suspend() - place the device in suspend
 927  * @pdev: PCI-Express device
 928  * @mesg: PM message
 929  */
 930 #ifdef CONFIG_PM
 931 static int ismt_suspend(struct pci_dev *pdev, pm_message_t mesg)
 932 {
 933         pci_save_state(pdev);
 934         pci_set_power_state(pdev, pci_choose_state(pdev, mesg));
 935         return 0;
 936 }
 937
 938 /**
 939  * ismt_resume() - PCI resume code
 940  * @pdev: PCI-Express device
 941  */
 942 static int ismt_resume(struct pci_dev *pdev)
 943 {
 944         pci_set_power_state(pdev, PCI_D0);
 945         pci_restore_state(pdev);
 946         return pci_enable_device(pdev);
 947 }
 948
 949 #else
 950
 951 #define ismt_suspend NULL
 952 #define ismt_resume NULL
 953
 954 #endif
 955
 956 static struct pci_driver ismt_driver = {
 957         .name = "ismt_smbus",
 958         .id_table = ismt_ids,
 959         .probe = ismt_probe,
 960         .remove = ismt_remove,
 961         .suspend = ismt_suspend,
 962         .resume = ismt_resume,
 963 };
 964
 965 module_pci_driver(ismt_driver);
 966
 967 MODULE_LICENSE("Dual BSD/GPL");
 968 MODULE_AUTHOR("Bill E. Brown <bill.e.brown@intel.com>");
 969 MODULE_DESCRIPTION("Intel SMBus Message Transport (iSMT) driver");