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_CDF_SMT     0x18ac
  79 #define PCI_DEVICE_ID_INTEL_DNV_SMT     0x19ac
  80 #define PCI_DEVICE_ID_INTEL_AVOTON_SMT  0x1f15
  81
  82 #define ISMT_DESC_ENTRIES       2       /* number of descriptor entries */
  83 #define ISMT_MAX_RETRIES        3       /* number of SMBus retries to attempt */
  84
  85 /* Hardware Descriptor Constants - Control Field */
  86 #define ISMT_DESC_CWRL  0x01    /* Command/Write Length */
  87 #define ISMT_DESC_BLK   0X04    /* Perform Block Transaction */
  88 #define ISMT_DESC_FAIR  0x08    /* Set fairness flag upon successful arbit. */
  89 #define ISMT_DESC_PEC   0x10    /* Packet Error Code */
  90 #define ISMT_DESC_I2C   0x20    /* I2C Enable */
  91 #define ISMT_DESC_INT   0x40    /* Interrupt */
  92 #define ISMT_DESC_SOE   0x80    /* Stop On Error */
  93
  94 /* Hardware Descriptor Constants - Status Field */
  95 #define ISMT_DESC_SCS   0x01    /* Success */
  96 #define ISMT_DESC_DLTO  0x04    /* Data Low Time Out */
  97 #define ISMT_DESC_NAK   0x08    /* NAK Received */
  98 #define ISMT_DESC_CRC   0x10    /* CRC Error */
  99 #define ISMT_DESC_CLTO  0x20    /* Clock Low Time Out */
 100 #define ISMT_DESC_COL   0x40    /* Collisions */
 101 #define ISMT_DESC_LPR   0x80    /* Large Packet Received */
 102
 103 /* Macros */
 104 #define ISMT_DESC_ADDR_RW(addr, rw) (((addr) << 1) | (rw))
 105
 106 /* iSMT General Register address offsets (SMBBAR + <addr>) */
 107 #define ISMT_GR_GCTRL           0x000   /* General Control */
 108 #define ISMT_GR_SMTICL          0x008   /* SMT Interrupt Cause Location */
 109 #define ISMT_GR_ERRINTMSK       0x010   /* Error Interrupt Mask */
 110 #define ISMT_GR_ERRAERMSK       0x014   /* Error AER Mask */
 111 #define ISMT_GR_ERRSTS          0x018   /* Error Status */
 112 #define ISMT_GR_ERRINFO         0x01c   /* Error Information */
 113
 114 /* iSMT Master Registers */
 115 #define ISMT_MSTR_MDBA          0x100   /* Master Descriptor Base Address */
 116 #define ISMT_MSTR_MCTRL         0x108   /* Master Control */
 117 #define ISMT_MSTR_MSTS          0x10c   /* Master Status */
 118 #define ISMT_MSTR_MDS           0x110   /* Master Descriptor Size */
 119 #define ISMT_MSTR_RPOLICY       0x114   /* Retry Policy */
 120
 121 /* iSMT Miscellaneous Registers */
 122 #define ISMT_SPGT       0x300   /* SMBus PHY Global Timing */
 123
 124 /* General Control Register (GCTRL) bit definitions */
 125 #define ISMT_GCTRL_TRST 0x04    /* Target Reset */
 126 #define ISMT_GCTRL_KILL 0x08    /* Kill */
 127 #define ISMT_GCTRL_SRST 0x40    /* Soft Reset */
 128
 129 /* Master Control Register (MCTRL) bit definitions */
 130 #define ISMT_MCTRL_SS   0x01            /* Start/Stop */
 131 #define ISMT_MCTRL_MEIE 0x10            /* Master Error Interrupt Enable */
 132 #define ISMT_MCTRL_FMHP 0x00ff0000      /* Firmware Master Head Ptr (FMHP) */
 133
 134 /* Master Status Register (MSTS) bit definitions */
 135 #define ISMT_MSTS_HMTP  0xff0000        /* HW Master Tail Pointer (HMTP) */
 136 #define ISMT_MSTS_MIS   0x20            /* Master Interrupt Status (MIS) */
 137 #define ISMT_MSTS_MEIS  0x10            /* Master Error Int Status (MEIS) */
 138 #define ISMT_MSTS_IP    0x01            /* In Progress */
 139
 140 /* Master Descriptor Size (MDS) bit definitions */
 141 #define ISMT_MDS_MASK   0xff    /* Master Descriptor Size mask (MDS) */
 142
 143 /* SMBus PHY Global Timing Register (SPGT) bit definitions */
 144 #define ISMT_SPGT_SPD_MASK      0xc0000000      /* SMBus Speed mask */
 145 #define ISMT_SPGT_SPD_80K       0x00            /* 80 kHz */
 146 #define ISMT_SPGT_SPD_100K      (0x1 << 30)     /* 100 kHz */
 147 #define ISMT_SPGT_SPD_400K      (0x2 << 30)     /* 400 kHz */
 148 #define ISMT_SPGT_SPD_1M        (0x3 << 30)     /* 1 MHz */
 149
 150
 151 /* MSI Control Register (MSICTL) bit definitions */
 152 #define ISMT_MSICTL_MSIE        0x01    /* MSI Enable */
 153
 154 /* iSMT Hardware Descriptor */
 155 struct ismt_desc {
 156         u8 tgtaddr_rw;  /* target address & r/w bit */
 157         u8 wr_len_cmd;  /* write length in bytes or a command */
 158         u8 rd_len;      /* read length */
 159         u8 control;     /* control bits */
 160         u8 status;      /* status bits */
 161         u8 retry;       /* collision retry and retry count */
 162         u8 rxbytes;     /* received bytes */
 163         u8 txbytes;     /* transmitted bytes */
 164         u32 dptr_low;   /* lower 32 bit of the data pointer */
 165         u32 dptr_high;  /* upper 32 bit of the data pointer */
 166 } __packed;
 167
 168 struct ismt_priv {
 169         struct i2c_adapter adapter;
 170         void __iomem *smba;                     /* PCI BAR */
 171         struct pci_dev *pci_dev;
 172         struct ismt_desc *hw;                   /* descriptor virt base addr */
 173         dma_addr_t io_rng_dma;                  /* descriptor HW base addr */
 174         u8 head;                                /* ring buffer head pointer */
 175         struct completion cmp;                  /* interrupt completion */
 176         u8 buffer[I2C_SMBUS_BLOCK_MAX + 16];    /* temp R/W data buffer */
 177 };
 178
 179 /**
 180  * ismt_ids - PCI device IDs supported by this driver
 181  */
 182 static const struct pci_device_id ismt_ids[] = {
 183         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT0) },
 184         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT1) },
 185         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_CDF_SMT) },
 186         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_DNV_SMT) },
 187         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_AVOTON_SMT) },
 188         { 0, }
 189 };
 190
 191 MODULE_DEVICE_TABLE(pci, ismt_ids);
 192
 193 /* Bus speed control bits for slow debuggers - refer to the docs for usage */
 194 static unsigned int bus_speed;
 195 module_param(bus_speed, uint, S_IRUGO);
 196 MODULE_PARM_DESC(bus_speed, "Bus Speed in kHz (0 = BIOS default)");
 197
 198 /**
 199  * __ismt_desc_dump() - dump the contents of a specific descriptor
 200  */
 201 static void __ismt_desc_dump(struct device *dev, const struct ismt_desc *desc)
 202 {
 203
 204         dev_dbg(dev, "Descriptor struct:  %p\n", desc);
 205         dev_dbg(dev, "\ttgtaddr_rw=0x%02X\n", desc->tgtaddr_rw);
 206         dev_dbg(dev, "\twr_len_cmd=0x%02X\n", desc->wr_len_cmd);
 207         dev_dbg(dev, "\trd_len=    0x%02X\n", desc->rd_len);
 208         dev_dbg(dev, "\tcontrol=   0x%02X\n", desc->control);
 209         dev_dbg(dev, "\tstatus=    0x%02X\n", desc->status);
 210         dev_dbg(dev, "\tretry=     0x%02X\n", desc->retry);
 211         dev_dbg(dev, "\trxbytes=   0x%02X\n", desc->rxbytes);
 212         dev_dbg(dev, "\ttxbytes=   0x%02X\n", desc->txbytes);
 213         dev_dbg(dev, "\tdptr_low=  0x%08X\n", desc->dptr_low);
 214         dev_dbg(dev, "\tdptr_high= 0x%08X\n", desc->dptr_high);
 215 }
 216 /**
 217  * ismt_desc_dump() - dump the contents of a descriptor for debug purposes
 218  * @priv: iSMT private data
 219  */
 220 static void ismt_desc_dump(struct ismt_priv *priv)
 221 {
 222         struct device *dev = &priv->pci_dev->dev;
 223         struct ismt_desc *desc = &priv->hw[priv->head];
 224
 225         dev_dbg(dev, "Dump of the descriptor struct:  0x%X\n", priv->head);
 226         __ismt_desc_dump(dev, desc);
 227 }
 228
 229 /**
 230  * ismt_gen_reg_dump() - dump the iSMT General Registers
 231  * @priv: iSMT private data
 232  */
 233 static void ismt_gen_reg_dump(struct ismt_priv *priv)
 234 {
 235         struct device *dev = &priv->pci_dev->dev;
 236
 237         dev_dbg(dev, "Dump of the iSMT General Registers\n");
 238         dev_dbg(dev, "  GCTRL.... : (0x%p)=0x%X\n",
 239                 priv->smba + ISMT_GR_GCTRL,
 240                 readl(priv->smba + ISMT_GR_GCTRL));
 241         dev_dbg(dev, "  SMTICL... : (0x%p)=0x%016llX\n",
 242                 priv->smba + ISMT_GR_SMTICL,
 243                 (long long unsigned int)readq(priv->smba + ISMT_GR_SMTICL));
 244         dev_dbg(dev, "  ERRINTMSK : (0x%p)=0x%X\n",
 245                 priv->smba + ISMT_GR_ERRINTMSK,
 246                 readl(priv->smba + ISMT_GR_ERRINTMSK));
 247         dev_dbg(dev, "  ERRAERMSK : (0x%p)=0x%X\n",
 248                 priv->smba + ISMT_GR_ERRAERMSK,
 249                 readl(priv->smba + ISMT_GR_ERRAERMSK));
 250         dev_dbg(dev, "  ERRSTS... : (0x%p)=0x%X\n",
 251                 priv->smba + ISMT_GR_ERRSTS,
 252                 readl(priv->smba + ISMT_GR_ERRSTS));
 253         dev_dbg(dev, "  ERRINFO.. : (0x%p)=0x%X\n",
 254                 priv->smba + ISMT_GR_ERRINFO,
 255                 readl(priv->smba + ISMT_GR_ERRINFO));
 256 }
 257
 258 /**
 259  * ismt_mstr_reg_dump() - dump the iSMT Master Registers
 260  * @priv: iSMT private data
 261  */
 262 static void ismt_mstr_reg_dump(struct ismt_priv *priv)
 263 {
 264         struct device *dev = &priv->pci_dev->dev;
 265
 266         dev_dbg(dev, "Dump of the iSMT Master Registers\n");
 267         dev_dbg(dev, "  MDBA..... : (0x%p)=0x%016llX\n",
 268                 priv->smba + ISMT_MSTR_MDBA,
 269                 (long long unsigned int)readq(priv->smba + ISMT_MSTR_MDBA));
 270         dev_dbg(dev, "  MCTRL.... : (0x%p)=0x%X\n",
 271                 priv->smba + ISMT_MSTR_MCTRL,
 272                 readl(priv->smba + ISMT_MSTR_MCTRL));
 273         dev_dbg(dev, "  MSTS..... : (0x%p)=0x%X\n",
 274                 priv->smba + ISMT_MSTR_MSTS,
 275                 readl(priv->smba + ISMT_MSTR_MSTS));
 276         dev_dbg(dev, "  MDS...... : (0x%p)=0x%X\n",
 277                 priv->smba + ISMT_MSTR_MDS,
 278                 readl(priv->smba + ISMT_MSTR_MDS));
 279         dev_dbg(dev, "  RPOLICY.. : (0x%p)=0x%X\n",
 280                 priv->smba + ISMT_MSTR_RPOLICY,
 281                 readl(priv->smba + ISMT_MSTR_RPOLICY));
 282         dev_dbg(dev, "  SPGT..... : (0x%p)=0x%X\n",
 283                 priv->smba + ISMT_SPGT,
 284                 readl(priv->smba + ISMT_SPGT));
 285 }
 286
 287 /**
 288  * ismt_submit_desc() - add a descriptor to the ring
 289  * @priv: iSMT private data
 290  */
 291 static void ismt_submit_desc(struct ismt_priv *priv)
 292 {
 293         uint fmhp;
 294         uint val;
 295
 296         ismt_desc_dump(priv);
 297         ismt_gen_reg_dump(priv);
 298         ismt_mstr_reg_dump(priv);
 299
 300         /* Set the FMHP (Firmware Master Head Pointer)*/
 301         fmhp = ((priv->head + 1) % ISMT_DESC_ENTRIES) << 16;
 302         val = readl(priv->smba + ISMT_MSTR_MCTRL);
 303         writel((val & ~ISMT_MCTRL_FMHP) | fmhp,
 304                priv->smba + ISMT_MSTR_MCTRL);
 305
 306         /* Set the start bit */
 307         val = readl(priv->smba + ISMT_MSTR_MCTRL);
 308         writel(val | ISMT_MCTRL_SS,
 309                priv->smba + ISMT_MSTR_MCTRL);
 310 }
 311
 312 /**
 313  * ismt_process_desc() - handle the completion of the descriptor
 314  * @desc: the iSMT hardware descriptor
 315  * @data: data buffer from the upper layer
 316  * @priv: ismt_priv struct holding our dma buffer
 317  * @size: SMBus transaction type
 318  * @read_write: flag to indicate if this is a read or write
 319  */
 320 static int ismt_process_desc(const struct ismt_desc *desc,
 321                              union i2c_smbus_data *data,
 322                              struct ismt_priv *priv, int size,
 323                              char read_write)
 324 {
 325         u8 *dma_buffer = PTR_ALIGN(&priv->buffer[0], 16);
 326
 327         dev_dbg(&priv->pci_dev->dev, "Processing completed descriptor\n");
 328         __ismt_desc_dump(&priv->pci_dev->dev, desc);
 329         ismt_gen_reg_dump(priv);
 330         ismt_mstr_reg_dump(priv);
 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                         if (desc->rxbytes != dma_buffer[0] + 1)
 348                                 return -EMSGSIZE;
 349
 350                         memcpy(data->block, dma_buffer, desc->rxbytes);
 351                         break;
 352                 case I2C_SMBUS_I2C_BLOCK_DATA:
 353                         memcpy(&data->block[1], dma_buffer, desc->rxbytes);
 354                         data->block[0] = desc->rxbytes;
 355                         break;
 356                 }
 357                 return 0;
 358         }
 359
 360         if (likely(desc->status & ISMT_DESC_NAK))
 361                 return -ENXIO;
 362
 363         if (desc->status & ISMT_DESC_CRC)
 364                 return -EBADMSG;
 365
 366         if (desc->status & ISMT_DESC_COL)
 367                 return -EAGAIN;
 368
 369         if (desc->status & ISMT_DESC_LPR)
 370                 return -EPROTO;
 371
 372         if (desc->status & (ISMT_DESC_DLTO | ISMT_DESC_CLTO))
 373                 return -ETIMEDOUT;
 374
 375         return -EIO;
 376 }
 377
 378 /**
 379  * ismt_access() - process an SMBus command
 380  * @adap: the i2c host adapter
 381  * @addr: address of the i2c/SMBus target
 382  * @flags: command options
 383  * @read_write: read from or write to device
 384  * @command: the i2c/SMBus command to issue
 385  * @size: SMBus transaction type
 386  * @data: read/write data buffer
 387  */
 388 static int ismt_access(struct i2c_adapter *adap, u16 addr,
 389                        unsigned short flags, char read_write, u8 command,
 390                        int size, union i2c_smbus_data *data)
 391 {
 392         int ret;
 393         unsigned long time_left;
 394         dma_addr_t dma_addr = 0; /* address of the data buffer */
 395         u8 dma_size = 0;
 396         enum dma_data_direction dma_direction = 0;
 397         struct ismt_desc *desc;
 398         struct ismt_priv *priv = i2c_get_adapdata(adap);
 399         struct device *dev = &priv->pci_dev->dev;
 400         u8 *dma_buffer = PTR_ALIGN(&priv->buffer[0], 16);
 401
 402         desc = &priv->hw[priv->head];
 403
 404         /* Initialize the DMA buffer */
 405         memset(priv->buffer, 0, sizeof(priv->buffer));
 406
 407         /* Initialize the descriptor */
 408         memset(desc, 0, sizeof(struct ismt_desc));
 409         desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, read_write);
 410
 411         /* Initialize common control bits */
 412         if (likely(pci_dev_msi_enabled(priv->pci_dev)))
 413                 desc->control = ISMT_DESC_INT | ISMT_DESC_FAIR;
 414         else
 415                 desc->control = ISMT_DESC_FAIR;
 416
 417         if ((flags & I2C_CLIENT_PEC) && (size != I2C_SMBUS_QUICK)
 418             && (size != I2C_SMBUS_I2C_BLOCK_DATA))
 419                 desc->control |= ISMT_DESC_PEC;
 420
 421         switch (size) {
 422         case I2C_SMBUS_QUICK:
 423                 dev_dbg(dev, "I2C_SMBUS_QUICK\n");
 424                 break;
 425
 426         case I2C_SMBUS_BYTE:
 427                 if (read_write == I2C_SMBUS_WRITE) {
 428                         /*
 429                          * Send Byte
 430                          * The command field contains the write data
 431                          */
 432                         dev_dbg(dev, "I2C_SMBUS_BYTE:  WRITE\n");
 433                         desc->control |= ISMT_DESC_CWRL;
 434                         desc->wr_len_cmd = command;
 435                 } else {
 436                         /* Receive Byte */
 437                         dev_dbg(dev, "I2C_SMBUS_BYTE:  READ\n");
 438                         dma_size = 1;
 439                         dma_direction = DMA_FROM_DEVICE;
 440                         desc->rd_len = 1;
 441                 }
 442                 break;
 443
 444         case I2C_SMBUS_BYTE_DATA:
 445                 if (read_write == I2C_SMBUS_WRITE) {
 446                         /*
 447                          * Write Byte
 448                          * Command plus 1 data byte
 449                          */
 450                         dev_dbg(dev, "I2C_SMBUS_BYTE_DATA:  WRITE\n");
 451                         desc->wr_len_cmd = 2;
 452                         dma_size = 2;
 453                         dma_direction = DMA_TO_DEVICE;
 454                         dma_buffer[0] = command;
 455                         dma_buffer[1] = data->byte;
 456                 } else {
 457                         /* Read Byte */
 458                         dev_dbg(dev, "I2C_SMBUS_BYTE_DATA:  READ\n");
 459                         desc->control |= ISMT_DESC_CWRL;
 460                         desc->wr_len_cmd = command;
 461                         desc->rd_len = 1;
 462                         dma_size = 1;
 463                         dma_direction = DMA_FROM_DEVICE;
 464                 }
 465                 break;
 466
 467         case I2C_SMBUS_WORD_DATA:
 468                 if (read_write == I2C_SMBUS_WRITE) {
 469                         /* Write Word */
 470                         dev_dbg(dev, "I2C_SMBUS_WORD_DATA:  WRITE\n");
 471                         desc->wr_len_cmd = 3;
 472                         dma_size = 3;
 473                         dma_direction = DMA_TO_DEVICE;
 474                         dma_buffer[0] = command;
 475                         dma_buffer[1] = data->word & 0xff;
 476                         dma_buffer[2] = data->word >> 8;
 477                 } else {
 478                         /* Read Word */
 479                         dev_dbg(dev, "I2C_SMBUS_WORD_DATA:  READ\n");
 480                         desc->wr_len_cmd = command;
 481                         desc->control |= ISMT_DESC_CWRL;
 482                         desc->rd_len = 2;
 483                         dma_size = 2;
 484                         dma_direction = DMA_FROM_DEVICE;
 485                 }
 486                 break;
 487
 488         case I2C_SMBUS_PROC_CALL:
 489                 dev_dbg(dev, "I2C_SMBUS_PROC_CALL\n");
 490                 desc->wr_len_cmd = 3;
 491                 desc->rd_len = 2;
 492                 dma_size = 3;
 493                 dma_direction = DMA_BIDIRECTIONAL;
 494                 dma_buffer[0] = command;
 495                 dma_buffer[1] = data->word & 0xff;
 496                 dma_buffer[2] = data->word >> 8;
 497                 break;
 498
 499         case I2C_SMBUS_BLOCK_DATA:
 500                 if (read_write == I2C_SMBUS_WRITE) {
 501                         /* Block Write */
 502                         dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA:  WRITE\n");
 503                         dma_size = data->block[0] + 1;
 504                         dma_direction = DMA_TO_DEVICE;
 505                         desc->wr_len_cmd = dma_size;
 506                         desc->control |= ISMT_DESC_BLK;
 507                         dma_buffer[0] = command;
 508                         memcpy(&dma_buffer[1], &data->block[1], dma_size - 1);
 509                 } else {
 510                         /* Block Read */
 511                         dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA:  READ\n");
 512                         dma_size = I2C_SMBUS_BLOCK_MAX;
 513                         dma_direction = DMA_FROM_DEVICE;
 514                         desc->rd_len = dma_size;
 515                         desc->wr_len_cmd = command;
 516                         desc->control |= (ISMT_DESC_BLK | ISMT_DESC_CWRL);
 517                 }
 518                 break;
 519
 520         case I2C_SMBUS_I2C_BLOCK_DATA:
 521                 /* Make sure the length is valid */
 522                 if (data->block[0] < 1)
 523                         data->block[0] = 1;
 524
 525                 if (data->block[0] > I2C_SMBUS_BLOCK_MAX)
 526                         data->block[0] = I2C_SMBUS_BLOCK_MAX;
 527
 528                 if (read_write == I2C_SMBUS_WRITE) {
 529                         /* i2c Block Write */
 530                         dev_dbg(dev, "I2C_SMBUS_I2C_BLOCK_DATA:  WRITE\n");
 531                         dma_size = data->block[0] + 1;
 532                         dma_direction = DMA_TO_DEVICE;
 533                         desc->wr_len_cmd = dma_size;
 534                         desc->control |= ISMT_DESC_I2C;
 535                         dma_buffer[0] = command;
 536                         memcpy(&dma_buffer[1], &data->block[1], dma_size - 1);
 537                 } else {
 538                         /* i2c Block Read */
 539                         dev_dbg(dev, "I2C_SMBUS_I2C_BLOCK_DATA:  READ\n");
 540                         dma_size = data->block[0];
 541                         dma_direction = DMA_FROM_DEVICE;
 542                         desc->rd_len = dma_size;
 543                         desc->wr_len_cmd = command;
 544                         desc->control |= (ISMT_DESC_I2C | ISMT_DESC_CWRL);
 545                         /*
 546                          * Per the "Table 15-15. I2C Commands",
 547                          * in the External Design Specification (EDS),
 548                          * (Document Number: 508084, Revision: 2.0),
 549                          * the _rw bit must be 0
 550                          */
 551                         desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, 0);
 552                 }
 553                 break;
 554
 555         default:
 556                 dev_err(dev, "Unsupported transaction %d\n",
 557                         size);
 558                 return -EOPNOTSUPP;
 559         }
 560
 561         /* map the data buffer */
 562         if (dma_size != 0) {
 563                 dev_dbg(dev, " dev=%p\n", dev);
 564                 dev_dbg(dev, " data=%p\n", data);
 565                 dev_dbg(dev, " dma_buffer=%p\n", dma_buffer);
 566                 dev_dbg(dev, " dma_size=%d\n", dma_size);
 567                 dev_dbg(dev, " dma_direction=%d\n", dma_direction);
 568
 569                 dma_addr = dma_map_single(dev,
 570                                       dma_buffer,
 571                                       dma_size,
 572                                       dma_direction);
 573
 574                 if (dma_mapping_error(dev, dma_addr)) {
 575                         dev_err(dev, "Error in mapping dma buffer %p\n",
 576                                 dma_buffer);
 577                         return -EIO;
 578                 }
 579
 580                 dev_dbg(dev, " dma_addr = %pad\n", &dma_addr);
 581
 582                 desc->dptr_low = lower_32_bits(dma_addr);
 583                 desc->dptr_high = upper_32_bits(dma_addr);
 584         }
 585
 586         reinit_completion(&priv->cmp);
 587
 588         /* Add the descriptor */
 589         ismt_submit_desc(priv);
 590
 591         /* Now we wait for interrupt completion, 1s */
 592         time_left = wait_for_completion_timeout(&priv->cmp, HZ*1);
 593
 594         /* unmap the data buffer */
 595         if (dma_size != 0)
 596                 dma_unmap_single(dev, dma_addr, dma_size, dma_direction);
 597
 598         if (unlikely(!time_left)) {
 599                 dev_err(dev, "completion wait timed out\n");
 600                 ret = -ETIMEDOUT;
 601                 goto out;
 602         }
 603
 604         /* do any post processing of the descriptor here */
 605         ret = ismt_process_desc(desc, data, priv, size, read_write);
 606
 607 out:
 608         /* Update the ring pointer */
 609         priv->head++;
 610         priv->head %= ISMT_DESC_ENTRIES;
 611
 612         return ret;
 613 }
 614
 615 /**
 616  * ismt_func() - report which i2c commands are supported by this adapter
 617  * @adap: the i2c host adapter
 618  */
 619 static u32 ismt_func(struct i2c_adapter *adap)
 620 {
 621         return I2C_FUNC_SMBUS_QUICK             |
 622                I2C_FUNC_SMBUS_BYTE              |
 623                I2C_FUNC_SMBUS_BYTE_DATA         |
 624                I2C_FUNC_SMBUS_WORD_DATA         |
 625                I2C_FUNC_SMBUS_PROC_CALL         |
 626                I2C_FUNC_SMBUS_BLOCK_DATA        |
 627                I2C_FUNC_SMBUS_I2C_BLOCK         |
 628                I2C_FUNC_SMBUS_PEC;
 629 }
 630
 631 /**
 632  * smbus_algorithm - the adapter algorithm and supported functionality
 633  * @smbus_xfer: the adapter algorithm
 634  * @functionality: functionality supported by the adapter
 635  */
 636 static const struct i2c_algorithm smbus_algorithm = {
 637         .smbus_xfer     = ismt_access,
 638         .functionality  = ismt_func,
 639 };
 640
 641 /**
 642  * ismt_handle_isr() - interrupt handler bottom half
 643  * @priv: iSMT private data
 644  */
 645 static irqreturn_t ismt_handle_isr(struct ismt_priv *priv)
 646 {
 647         complete(&priv->cmp);
 648
 649         return IRQ_HANDLED;
 650 }
 651
 652
 653 /**
 654  * ismt_do_interrupt() - IRQ interrupt handler
 655  * @vec: interrupt vector
 656  * @data: iSMT private data
 657  */
 658 static irqreturn_t ismt_do_interrupt(int vec, void *data)
 659 {
 660         u32 val;
 661         struct ismt_priv *priv = data;
 662
 663         /*
 664          * check to see it's our interrupt, return IRQ_NONE if not ours
 665          * since we are sharing interrupt
 666          */
 667         val = readl(priv->smba + ISMT_MSTR_MSTS);
 668
 669         if (!(val & (ISMT_MSTS_MIS | ISMT_MSTS_MEIS)))
 670                 return IRQ_NONE;
 671         else
 672                 writel(val | ISMT_MSTS_MIS | ISMT_MSTS_MEIS,
 673                        priv->smba + ISMT_MSTR_MSTS);
 674
 675         return ismt_handle_isr(priv);
 676 }
 677
 678 /**
 679  * ismt_do_msi_interrupt() - MSI interrupt handler
 680  * @vec: interrupt vector
 681  * @data: iSMT private data
 682  */
 683 static irqreturn_t ismt_do_msi_interrupt(int vec, void *data)
 684 {
 685         return ismt_handle_isr(data);
 686 }
 687
 688 /**
 689  * ismt_hw_init() - initialize the iSMT hardware
 690  * @priv: iSMT private data
 691  */
 692 static void ismt_hw_init(struct ismt_priv *priv)
 693 {
 694         u32 val;
 695         struct device *dev = &priv->pci_dev->dev;
 696
 697         /* initialize the Master Descriptor Base Address (MDBA) */
 698         writeq(priv->io_rng_dma, priv->smba + ISMT_MSTR_MDBA);
 699
 700         /* initialize the Master Control Register (MCTRL) */
 701         writel(ISMT_MCTRL_MEIE, priv->smba + ISMT_MSTR_MCTRL);
 702
 703         /* initialize the Master Status Register (MSTS) */
 704         writel(0, priv->smba + ISMT_MSTR_MSTS);
 705
 706         /* initialize the Master Descriptor Size (MDS) */
 707         val = readl(priv->smba + ISMT_MSTR_MDS);
 708         writel((val & ~ISMT_MDS_MASK) | (ISMT_DESC_ENTRIES - 1),
 709                 priv->smba + ISMT_MSTR_MDS);
 710
 711         /*
 712          * Set the SMBus speed (could use this for slow HW debuggers)
 713          */
 714
 715         val = readl(priv->smba + ISMT_SPGT);
 716
 717         switch (bus_speed) {
 718         case 0:
 719                 break;
 720
 721         case 80:
 722                 dev_dbg(dev, "Setting SMBus clock to 80 kHz\n");
 723                 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_80K),
 724                         priv->smba + ISMT_SPGT);
 725                 break;
 726
 727         case 100:
 728                 dev_dbg(dev, "Setting SMBus clock to 100 kHz\n");
 729                 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_100K),
 730                         priv->smba + ISMT_SPGT);
 731                 break;
 732
 733         case 400:
 734                 dev_dbg(dev, "Setting SMBus clock to 400 kHz\n");
 735                 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_400K),
 736                         priv->smba + ISMT_SPGT);
 737                 break;
 738
 739         case 1000:
 740                 dev_dbg(dev, "Setting SMBus clock to 1000 kHz\n");
 741                 writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_1M),
 742                         priv->smba + ISMT_SPGT);
 743                 break;
 744
 745         default:
 746                 dev_warn(dev, "Invalid SMBus clock speed, only 0, 80, 100, 400, and 1000 are valid\n");
 747                 break;
 748         }
 749
 750         val = readl(priv->smba + ISMT_SPGT);
 751
 752         switch (val & ISMT_SPGT_SPD_MASK) {
 753         case ISMT_SPGT_SPD_80K:
 754                 bus_speed = 80;
 755                 break;
 756         case ISMT_SPGT_SPD_100K:
 757                 bus_speed = 100;
 758                 break;
 759         case ISMT_SPGT_SPD_400K:
 760                 bus_speed = 400;
 761                 break;
 762         case ISMT_SPGT_SPD_1M:
 763                 bus_speed = 1000;
 764                 break;
 765         }
 766         dev_dbg(dev, "SMBus clock is running at %d kHz\n", bus_speed);
 767 }
 768
 769 /**
 770  * ismt_dev_init() - initialize the iSMT data structures
 771  * @priv: iSMT private data
 772  */
 773 static int ismt_dev_init(struct ismt_priv *priv)
 774 {
 775         /* allocate memory for the descriptor */
 776         priv->hw = dmam_alloc_coherent(&priv->pci_dev->dev,
 777                                        (ISMT_DESC_ENTRIES
 778                                                * sizeof(struct ismt_desc)),
 779                                        &priv->io_rng_dma,
 780                                        GFP_KERNEL);
 781         if (!priv->hw)
 782                 return -ENOMEM;
 783
 784         priv->head = 0;
 785         init_completion(&priv->cmp);
 786
 787         return 0;
 788 }
 789
 790 /**
 791  * ismt_int_init() - initialize interrupts
 792  * @priv: iSMT private data
 793  */
 794 static int ismt_int_init(struct ismt_priv *priv)
 795 {
 796         int err;
 797
 798         /* Try using MSI interrupts */
 799         err = pci_enable_msi(priv->pci_dev);
 800         if (err)
 801                 goto intx;
 802
 803         err = devm_request_irq(&priv->pci_dev->dev,
 804                                priv->pci_dev->irq,
 805                                ismt_do_msi_interrupt,
 806                                0,
 807                                "ismt-msi",
 808                                priv);
 809         if (err) {
 810                 pci_disable_msi(priv->pci_dev);
 811                 goto intx;
 812         }
 813
 814         return 0;
 815
 816         /* Try using legacy interrupts */
 817 intx:
 818         dev_warn(&priv->pci_dev->dev,
 819                  "Unable to use MSI interrupts, falling back to legacy\n");
 820
 821         err = devm_request_irq(&priv->pci_dev->dev,
 822                                priv->pci_dev->irq,
 823                                ismt_do_interrupt,
 824                                IRQF_SHARED,
 825                                "ismt-intx",
 826                                priv);
 827         if (err) {
 828                 dev_err(&priv->pci_dev->dev, "no usable interrupts\n");
 829                 return err;
 830         }
 831
 832         return 0;
 833 }
 834
 835 static struct pci_driver ismt_driver;
 836
 837 /**
 838  * ismt_probe() - probe for iSMT devices
 839  * @pdev: PCI-Express device
 840  * @id: PCI-Express device ID
 841  */
 842 static int
 843 ismt_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 844 {
 845         int err;
 846         struct ismt_priv *priv;
 847         unsigned long start, len;
 848
 849         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 850         if (!priv)
 851                 return -ENOMEM;
 852
 853         pci_set_drvdata(pdev, priv);
 854
 855         i2c_set_adapdata(&priv->adapter, priv);
 856         priv->adapter.owner = THIS_MODULE;
 857         priv->adapter.class = I2C_CLASS_HWMON;
 858         priv->adapter.algo = &smbus_algorithm;
 859         priv->adapter.dev.parent = &pdev->dev;
 860         ACPI_COMPANION_SET(&priv->adapter.dev, ACPI_COMPANION(&pdev->dev));
 861         priv->adapter.retries = ISMT_MAX_RETRIES;
 862
 863         priv->pci_dev = pdev;
 864
 865         err = pcim_enable_device(pdev);
 866         if (err) {
 867                 dev_err(&pdev->dev, "Failed to enable SMBus PCI device (%d)\n",
 868                         err);
 869                 return err;
 870         }
 871
 872         /* enable bus mastering */
 873         pci_set_master(pdev);
 874
 875         /* Determine the address of the SMBus area */
 876         start = pci_resource_start(pdev, SMBBAR);
 877         len = pci_resource_len(pdev, SMBBAR);
 878         if (!start || !len) {
 879                 dev_err(&pdev->dev,
 880                         "SMBus base address uninitialized, upgrade BIOS\n");
 881                 return -ENODEV;
 882         }
 883
 884         snprintf(priv->adapter.name, sizeof(priv->adapter.name),
 885                  "SMBus iSMT adapter at %lx", start);
 886
 887         dev_dbg(&priv->pci_dev->dev, " start=0x%lX\n", start);
 888         dev_dbg(&priv->pci_dev->dev, " len=0x%lX\n", len);
 889
 890         err = acpi_check_resource_conflict(&pdev->resource[SMBBAR]);
 891         if (err) {
 892                 dev_err(&pdev->dev, "ACPI resource conflict!\n");
 893                 return err;
 894         }
 895
 896         err = pci_request_region(pdev, SMBBAR, ismt_driver.name);
 897         if (err) {
 898                 dev_err(&pdev->dev,
 899                         "Failed to request SMBus region 0x%lx-0x%lx\n",
 900                         start, start + len);
 901                 return err;
 902         }
 903
 904         priv->smba = pcim_iomap(pdev, SMBBAR, len);
 905         if (!priv->smba) {
 906                 dev_err(&pdev->dev, "Unable to ioremap SMBus BAR\n");
 907                 return -ENODEV;
 908         }
 909
 910         if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(64)) != 0) ||
 911             (pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64)) != 0)) {
 912                 if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(32)) != 0) ||
 913                     (pci_set_consistent_dma_mask(pdev,
 914                                                  DMA_BIT_MASK(32)) != 0)) {
 915                         dev_err(&pdev->dev, "pci_set_dma_mask fail %p\n",
 916                                 pdev);
 917                         return -ENODEV;
 918                 }
 919         }
 920
 921         err = ismt_dev_init(priv);
 922         if (err)
 923                 return err;
 924
 925         ismt_hw_init(priv);
 926
 927         err = ismt_int_init(priv);
 928         if (err)
 929                 return err;
 930
 931         err = i2c_add_adapter(&priv->adapter);
 932         if (err)
 933                 return -ENODEV;
 934         return 0;
 935 }
 936
 937 /**
 938  * ismt_remove() - release driver resources
 939  * @pdev: PCI-Express device
 940  */
 941 static void ismt_remove(struct pci_dev *pdev)
 942 {
 943         struct ismt_priv *priv = pci_get_drvdata(pdev);
 944
 945         i2c_del_adapter(&priv->adapter);
 946 }
 947
 948 static struct pci_driver ismt_driver = {
 949         .name = "ismt_smbus",
 950         .id_table = ismt_ids,
 951         .probe = ismt_probe,
 952         .remove = ismt_remove,
 953 };
 954
 955 module_pci_driver(ismt_driver);
 956
 957 MODULE_LICENSE("Dual BSD/GPL");
 958 MODULE_AUTHOR("Bill E. Brown <bill.e.brown@intel.com>");
 959 MODULE_DESCRIPTION("Intel SMBus Message Transport (iSMT) driver");