drivers/i2c/busses/i2c-xgene-slimpro.c

   1 /*
   2  * X-Gene SLIMpro I2C Driver
   3  *
   4  * Copyright (c) 2014, Applied Micro Circuits Corporation
   5  * Author: Feng Kan <fkan@apm.com>
   6  * Author: Hieu Le <hnle@apm.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU 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, see <http://www.gnu.org/licenses/>.
  20  *
  21  * This driver provides support for X-Gene SLIMpro I2C device access
  22  * using the APM X-Gene SLIMpro mailbox driver.
  23  *
  24  */
  25 #include <linux/acpi.h>
  26 #include <linux/dma-mapping.h>
  27 #include <linux/i2c.h>
  28 #include <linux/interrupt.h>
  29 #include <linux/mailbox_client.h>
  30 #include <linux/module.h>
  31 #include <linux/of.h>
  32 #include <linux/platform_device.h>
  33 #include <linux/version.h>
  34
  35 #define MAILBOX_OP_TIMEOUT              1000    /* Operation time out in ms */
  36 #define MAILBOX_I2C_INDEX               0
  37 #define SLIMPRO_IIC_BUS                 1       /* Use I2C bus 1 only */
  38
  39 #define SMBUS_CMD_LEN                   1
  40 #define BYTE_DATA                       1
  41 #define WORD_DATA                       2
  42 #define BLOCK_DATA                      3
  43
  44 #define SLIMPRO_IIC_I2C_PROTOCOL        0
  45 #define SLIMPRO_IIC_SMB_PROTOCOL        1
  46
  47 #define SLIMPRO_IIC_READ                0
  48 #define SLIMPRO_IIC_WRITE               1
  49
  50 #define IIC_SMB_WITHOUT_DATA_LEN        0
  51 #define IIC_SMB_WITH_DATA_LEN           1
  52
  53 #define SLIMPRO_DEBUG_MSG               0
  54 #define SLIMPRO_MSG_TYPE_SHIFT          28
  55 #define SLIMPRO_DBG_SUBTYPE_I2C1READ    4
  56 #define SLIMPRO_DBGMSG_TYPE_SHIFT       24
  57 #define SLIMPRO_DBGMSG_TYPE_MASK        0x0F000000U
  58 #define SLIMPRO_IIC_DEV_SHIFT           23
  59 #define SLIMPRO_IIC_DEV_MASK            0x00800000U
  60 #define SLIMPRO_IIC_DEVID_SHIFT         13
  61 #define SLIMPRO_IIC_DEVID_MASK          0x007FE000U
  62 #define SLIMPRO_IIC_RW_SHIFT            12
  63 #define SLIMPRO_IIC_RW_MASK             0x00001000U
  64 #define SLIMPRO_IIC_PROTO_SHIFT         11
  65 #define SLIMPRO_IIC_PROTO_MASK          0x00000800U
  66 #define SLIMPRO_IIC_ADDRLEN_SHIFT       8
  67 #define SLIMPRO_IIC_ADDRLEN_MASK        0x00000700U
  68 #define SLIMPRO_IIC_DATALEN_SHIFT       0
  69 #define SLIMPRO_IIC_DATALEN_MASK        0x000000FFU
  70
  71 /*
  72  * SLIMpro I2C message encode
  73  *
  74  * dev          - Controller number (0-based)
  75  * chip         - I2C chip address
  76  * op           - SLIMPRO_IIC_READ or SLIMPRO_IIC_WRITE
  77  * proto        - SLIMPRO_IIC_SMB_PROTOCOL or SLIMPRO_IIC_I2C_PROTOCOL
  78  * addrlen      - Length of the address field
  79  * datalen      - Length of the data field
  80  */
  81 #define SLIMPRO_IIC_ENCODE_MSG(dev, chip, op, proto, addrlen, datalen) \
  82         ((SLIMPRO_DEBUG_MSG << SLIMPRO_MSG_TYPE_SHIFT) | \
  83         ((SLIMPRO_DBG_SUBTYPE_I2C1READ << SLIMPRO_DBGMSG_TYPE_SHIFT) & \
  84         SLIMPRO_DBGMSG_TYPE_MASK) | \
  85         ((dev << SLIMPRO_IIC_DEV_SHIFT) & SLIMPRO_IIC_DEV_MASK) | \
  86         ((chip << SLIMPRO_IIC_DEVID_SHIFT) & SLIMPRO_IIC_DEVID_MASK) | \
  87         ((op << SLIMPRO_IIC_RW_SHIFT) & SLIMPRO_IIC_RW_MASK) | \
  88         ((proto << SLIMPRO_IIC_PROTO_SHIFT) & SLIMPRO_IIC_PROTO_MASK) | \
  89         ((addrlen << SLIMPRO_IIC_ADDRLEN_SHIFT) & SLIMPRO_IIC_ADDRLEN_MASK) | \
  90         ((datalen << SLIMPRO_IIC_DATALEN_SHIFT) & SLIMPRO_IIC_DATALEN_MASK))
  91
  92 /*
  93  * Encode for upper address for block data
  94  */
  95 #define SLIMPRO_IIC_ENCODE_FLAG_BUFADDR                 0x80000000
  96 #define SLIMPRO_IIC_ENCODE_FLAG_WITH_DATA_LEN(a)        ((u32) (((a) << 30) \
  97                                                                 & 0x40000000))
  98 #define SLIMPRO_IIC_ENCODE_UPPER_BUFADDR(a)             ((u32) (((a) >> 12) \
  99                                                                 & 0x3FF00000))
 100 #define SLIMPRO_IIC_ENCODE_ADDR(a)                      ((a) & 0x000FFFFF)
 101
 102 struct slimpro_i2c_dev {
 103         struct i2c_adapter adapter;
 104         struct device *dev;
 105         struct mbox_chan *mbox_chan;
 106         struct mbox_client mbox_client;
 107         struct completion rd_complete;
 108         u8 dma_buffer[I2C_SMBUS_BLOCK_MAX + 1]; /* dma_buffer[0] is used for length */
 109         u32 *resp_msg;
 110 };
 111
 112 #define to_slimpro_i2c_dev(cl)  \
 113                 container_of(cl, struct slimpro_i2c_dev, mbox_client)
 114
 115 static void slimpro_i2c_rx_cb(struct mbox_client *cl, void *mssg)
 116 {
 117         struct slimpro_i2c_dev *ctx = to_slimpro_i2c_dev(cl);
 118
 119         /*
 120          * Response message format:
 121          * mssg[0] is the return code of the operation
 122          * mssg[1] is the first data word
 123          * mssg[2] is NOT used
 124          */
 125         if (ctx->resp_msg)
 126                 *ctx->resp_msg = ((u32 *)mssg)[1];
 127
 128         if (ctx->mbox_client.tx_block)
 129                 complete(&ctx->rd_complete);
 130 }
 131
 132 static int start_i2c_msg_xfer(struct slimpro_i2c_dev *ctx)
 133 {
 134         if (ctx->mbox_client.tx_block) {
 135                 if (!wait_for_completion_timeout(&ctx->rd_complete,
 136                                                  msecs_to_jiffies(MAILBOX_OP_TIMEOUT)))
 137                         return -ETIMEDOUT;
 138         }
 139
 140         /* Check of invalid data or no device */
 141         if (*ctx->resp_msg == 0xffffffff)
 142                 return -ENODEV;
 143
 144         return 0;
 145 }
 146
 147 static int slimpro_i2c_rd(struct slimpro_i2c_dev *ctx, u32 chip,
 148                           u32 addr, u32 addrlen, u32 protocol,
 149                           u32 readlen, u32 *data)
 150 {
 151         u32 msg[3];
 152         int rc;
 153
 154         msg[0] = SLIMPRO_IIC_ENCODE_MSG(SLIMPRO_IIC_BUS, chip,
 155                                         SLIMPRO_IIC_READ, protocol, addrlen, readlen);
 156         msg[1] = SLIMPRO_IIC_ENCODE_ADDR(addr);
 157         msg[2] = 0;
 158         ctx->resp_msg = data;
 159         rc = mbox_send_message(ctx->mbox_chan, &msg);
 160         if (rc < 0)
 161                 goto err;
 162
 163         rc = start_i2c_msg_xfer(ctx);
 164 err:
 165         ctx->resp_msg = NULL;
 166         return rc;
 167 }
 168
 169 static int slimpro_i2c_wr(struct slimpro_i2c_dev *ctx, u32 chip,
 170                           u32 addr, u32 addrlen, u32 protocol, u32 writelen,
 171                           u32 data)
 172 {
 173         u32 msg[3];
 174         int rc;
 175
 176         msg[0] = SLIMPRO_IIC_ENCODE_MSG(SLIMPRO_IIC_BUS, chip,
 177                                         SLIMPRO_IIC_WRITE, protocol, addrlen, writelen);
 178         msg[1] = SLIMPRO_IIC_ENCODE_ADDR(addr);
 179         msg[2] = data;
 180         ctx->resp_msg = msg;
 181
 182         rc = mbox_send_message(ctx->mbox_chan, &msg);
 183         if (rc < 0)
 184                 goto err;
 185
 186         rc = start_i2c_msg_xfer(ctx);
 187 err:
 188         ctx->resp_msg = NULL;
 189         return rc;
 190 }
 191
 192 static int slimpro_i2c_blkrd(struct slimpro_i2c_dev *ctx, u32 chip, u32 addr,
 193                              u32 addrlen, u32 protocol, u32 readlen,
 194                              u32 with_data_len, void *data)
 195 {
 196         dma_addr_t paddr;
 197         u32 msg[3];
 198         int rc;
 199
 200         paddr = dma_map_single(ctx->dev, ctx->dma_buffer, readlen, DMA_FROM_DEVICE);
 201         if (dma_mapping_error(ctx->dev, paddr)) {
 202                 dev_err(&ctx->adapter.dev, "Error in mapping dma buffer %p\n",
 203                         ctx->dma_buffer);
 204                 rc = -ENOMEM;
 205                 goto err;
 206         }
 207
 208         msg[0] = SLIMPRO_IIC_ENCODE_MSG(SLIMPRO_IIC_BUS, chip, SLIMPRO_IIC_READ,
 209                                         protocol, addrlen, readlen);
 210         msg[1] = SLIMPRO_IIC_ENCODE_FLAG_BUFADDR |
 211                  SLIMPRO_IIC_ENCODE_FLAG_WITH_DATA_LEN(with_data_len) |
 212                  SLIMPRO_IIC_ENCODE_UPPER_BUFADDR(paddr) |
 213                  SLIMPRO_IIC_ENCODE_ADDR(addr);
 214         msg[2] = (u32)paddr;
 215         ctx->resp_msg = msg;
 216
 217         rc = mbox_send_message(ctx->mbox_chan, &msg);
 218         if (rc < 0)
 219                 goto err_unmap;
 220
 221         rc = start_i2c_msg_xfer(ctx);
 222
 223         /* Copy to destination */
 224         memcpy(data, ctx->dma_buffer, readlen);
 225
 226 err_unmap:
 227         dma_unmap_single(ctx->dev, paddr, readlen, DMA_FROM_DEVICE);
 228 err:
 229         ctx->resp_msg = NULL;
 230         return rc;
 231 }
 232
 233 static int slimpro_i2c_blkwr(struct slimpro_i2c_dev *ctx, u32 chip,
 234                              u32 addr, u32 addrlen, u32 protocol, u32 writelen,
 235                              void *data)
 236 {
 237         dma_addr_t paddr;
 238         u32 msg[3];
 239         int rc;
 240
 241         memcpy(ctx->dma_buffer, data, writelen);
 242         paddr = dma_map_single(ctx->dev, ctx->dma_buffer, writelen,
 243                                DMA_TO_DEVICE);
 244         if (dma_mapping_error(ctx->dev, paddr)) {
 245                 dev_err(&ctx->adapter.dev, "Error in mapping dma buffer %p\n",
 246                         ctx->dma_buffer);
 247                 rc = -ENOMEM;
 248                 goto err;
 249         }
 250
 251         msg[0] = SLIMPRO_IIC_ENCODE_MSG(SLIMPRO_IIC_BUS, chip, SLIMPRO_IIC_WRITE,
 252                                         protocol, addrlen, writelen);
 253         msg[1] = SLIMPRO_IIC_ENCODE_FLAG_BUFADDR |
 254                  SLIMPRO_IIC_ENCODE_UPPER_BUFADDR(paddr) |
 255                  SLIMPRO_IIC_ENCODE_ADDR(addr);
 256         msg[2] = (u32)paddr;
 257         ctx->resp_msg = msg;
 258
 259         if (ctx->mbox_client.tx_block)
 260                 reinit_completion(&ctx->rd_complete);
 261
 262         rc = mbox_send_message(ctx->mbox_chan, &msg);
 263         if (rc < 0)
 264                 goto err_unmap;
 265
 266         rc = start_i2c_msg_xfer(ctx);
 267
 268 err_unmap:
 269         dma_unmap_single(ctx->dev, paddr, writelen, DMA_TO_DEVICE);
 270 err:
 271         ctx->resp_msg = NULL;
 272         return rc;
 273 }
 274
 275 static int xgene_slimpro_i2c_xfer(struct i2c_adapter *adap, u16 addr,
 276                                   unsigned short flags, char read_write,
 277                                   u8 command, int size,
 278                                   union i2c_smbus_data *data)
 279 {
 280         struct slimpro_i2c_dev *ctx = i2c_get_adapdata(adap);
 281         int ret = -EOPNOTSUPP;
 282         u32 val;
 283
 284         switch (size) {
 285         case I2C_SMBUS_BYTE:
 286                 if (read_write == I2C_SMBUS_READ) {
 287                         ret = slimpro_i2c_rd(ctx, addr, 0, 0,
 288                                              SLIMPRO_IIC_SMB_PROTOCOL,
 289                                              BYTE_DATA, &val);
 290                         data->byte = val;
 291                 } else {
 292                         ret = slimpro_i2c_wr(ctx, addr, command, SMBUS_CMD_LEN,
 293                                              SLIMPRO_IIC_SMB_PROTOCOL,
 294                                              0, 0);
 295                 }
 296                 break;
 297         case I2C_SMBUS_BYTE_DATA:
 298                 if (read_write == I2C_SMBUS_READ) {
 299                         ret = slimpro_i2c_rd(ctx, addr, command, SMBUS_CMD_LEN,
 300                                              SLIMPRO_IIC_SMB_PROTOCOL,
 301                                              BYTE_DATA, &val);
 302                         data->byte = val;
 303                 } else {
 304                         val = data->byte;
 305                         ret = slimpro_i2c_wr(ctx, addr, command, SMBUS_CMD_LEN,
 306                                              SLIMPRO_IIC_SMB_PROTOCOL,
 307                                              BYTE_DATA, val);
 308                 }
 309                 break;
 310         case I2C_SMBUS_WORD_DATA:
 311                 if (read_write == I2C_SMBUS_READ) {
 312                         ret = slimpro_i2c_rd(ctx, addr, command, SMBUS_CMD_LEN,
 313                                              SLIMPRO_IIC_SMB_PROTOCOL,
 314                                              WORD_DATA, &val);
 315                         data->word = val;
 316                 } else {
 317                         val = data->word;
 318                         ret = slimpro_i2c_wr(ctx, addr, command, SMBUS_CMD_LEN,
 319                                              SLIMPRO_IIC_SMB_PROTOCOL,
 320                                              WORD_DATA, val);
 321                 }
 322                 break;
 323         case I2C_SMBUS_BLOCK_DATA:
 324                 if (read_write == I2C_SMBUS_READ) {
 325                         ret = slimpro_i2c_blkrd(ctx, addr, command,
 326                                                 SMBUS_CMD_LEN,
 327                                                 SLIMPRO_IIC_SMB_PROTOCOL,
 328                                                 I2C_SMBUS_BLOCK_MAX + 1,
 329                                                 IIC_SMB_WITH_DATA_LEN,
 330                                                 &data->block[0]);
 331
 332                 } else {
 333                         ret = slimpro_i2c_blkwr(ctx, addr, command,
 334                                                 SMBUS_CMD_LEN,
 335                                                 SLIMPRO_IIC_SMB_PROTOCOL,
 336                                                 data->block[0] + 1,
 337                                                 &data->block[0]);
 338                 }
 339                 break;
 340         case I2C_SMBUS_I2C_BLOCK_DATA:
 341                 if (read_write == I2C_SMBUS_READ) {
 342                         ret = slimpro_i2c_blkrd(ctx, addr,
 343                                                 command,
 344                                                 SMBUS_CMD_LEN,
 345                                                 SLIMPRO_IIC_I2C_PROTOCOL,
 346                                                 I2C_SMBUS_BLOCK_MAX,
 347                                                 IIC_SMB_WITHOUT_DATA_LEN,
 348                                                 &data->block[1]);
 349                 } else {
 350                         ret = slimpro_i2c_blkwr(ctx, addr, command,
 351                                                 SMBUS_CMD_LEN,
 352                                                 SLIMPRO_IIC_I2C_PROTOCOL,
 353                                                 data->block[0],
 354                                                 &data->block[1]);
 355                 }
 356                 break;
 357         default:
 358                 break;
 359         }
 360         return ret;
 361 }
 362
 363 /*
 364 * Return list of supported functionality.
 365 */
 366 static u32 xgene_slimpro_i2c_func(struct i2c_adapter *adapter)
 367 {
 368         return I2C_FUNC_SMBUS_BYTE |
 369                 I2C_FUNC_SMBUS_BYTE_DATA |
 370                 I2C_FUNC_SMBUS_WORD_DATA |
 371                 I2C_FUNC_SMBUS_BLOCK_DATA |
 372                 I2C_FUNC_SMBUS_I2C_BLOCK;
 373 }
 374
 375 static struct i2c_algorithm xgene_slimpro_i2c_algorithm = {
 376         .smbus_xfer = xgene_slimpro_i2c_xfer,
 377         .functionality = xgene_slimpro_i2c_func,
 378 };
 379
 380 static int xgene_slimpro_i2c_probe(struct platform_device *pdev)
 381 {
 382         struct slimpro_i2c_dev *ctx;
 383         struct i2c_adapter *adapter;
 384         struct mbox_client *cl;
 385         int rc;
 386
 387         ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
 388         if (!ctx)
 389                 return -ENOMEM;
 390
 391         ctx->dev = &pdev->dev;
 392         platform_set_drvdata(pdev, ctx);
 393         cl = &ctx->mbox_client;
 394
 395         /* Request mailbox channel */
 396         cl->dev = &pdev->dev;
 397         cl->rx_callback = slimpro_i2c_rx_cb;
 398         cl->tx_block = true;
 399         init_completion(&ctx->rd_complete);
 400         cl->tx_tout = MAILBOX_OP_TIMEOUT;
 401         cl->knows_txdone = false;
 402         ctx->mbox_chan = mbox_request_channel(cl, MAILBOX_I2C_INDEX);
 403         if (IS_ERR(ctx->mbox_chan)) {
 404                 dev_err(&pdev->dev, "i2c mailbox channel request failed\n");
 405                 return PTR_ERR(ctx->mbox_chan);
 406         }
 407
 408         rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
 409         if (rc)
 410                 dev_warn(&pdev->dev, "Unable to set dma mask\n");
 411
 412         /* Setup I2C adapter */
 413         adapter = &ctx->adapter;
 414         snprintf(adapter->name, sizeof(adapter->name), "MAILBOX I2C");
 415         adapter->algo = &xgene_slimpro_i2c_algorithm;
 416         adapter->class = I2C_CLASS_HWMON;
 417         adapter->dev.parent = &pdev->dev;
 418         i2c_set_adapdata(adapter, ctx);
 419         rc = i2c_add_adapter(adapter);
 420         if (rc) {
 421                 dev_err(&pdev->dev, "Adapter registeration failed\n");
 422                 mbox_free_channel(ctx->mbox_chan);
 423                 return rc;
 424         }
 425
 426         dev_info(&pdev->dev, "Mailbox I2C Adapter registered\n");
 427         return 0;
 428 }
 429
 430 static int xgene_slimpro_i2c_remove(struct platform_device *pdev)
 431 {
 432         struct slimpro_i2c_dev *ctx = platform_get_drvdata(pdev);
 433
 434         i2c_del_adapter(&ctx->adapter);
 435
 436         mbox_free_channel(ctx->mbox_chan);
 437
 438         return 0;
 439 }
 440
 441 static const struct of_device_id xgene_slimpro_i2c_dt_ids[] = {
 442         {.compatible = "apm,xgene-slimpro-i2c" },
 443         {},
 444 };
 445 MODULE_DEVICE_TABLE(of, xgene_slimpro_i2c_dt_ids);
 446
 447 #ifdef CONFIG_ACPI
 448 static const struct acpi_device_id xgene_slimpro_i2c_acpi_ids[] = {
 449         {"APMC0D40", 0},
 450         {}
 451 };
 452 MODULE_DEVICE_TABLE(acpi, xgene_slimpro_i2c_acpi_ids);
 453 #endif
 454
 455 static struct platform_driver xgene_slimpro_i2c_driver = {
 456         .probe  = xgene_slimpro_i2c_probe,
 457         .remove = xgene_slimpro_i2c_remove,
 458         .driver = {
 459                 .name   = "xgene-slimpro-i2c",
 460                 .of_match_table = of_match_ptr(xgene_slimpro_i2c_dt_ids),
 461                 .acpi_match_table = ACPI_PTR(xgene_slimpro_i2c_acpi_ids)
 462         },
 463 };
 464
 465 module_platform_driver(xgene_slimpro_i2c_driver);
 466
 467 MODULE_DESCRIPTION("APM X-Gene SLIMpro I2C driver");
 468 MODULE_AUTHOR("Feng Kan <fkan@apm.com>");
 469 MODULE_AUTHOR("Hieu Le <hnle@apm.com>");
 470 MODULE_LICENSE("GPL");