drivers/acpi/i2c_ec.c

   1 /*
   2  * SMBus driver for ACPI Embedded Controller ($Revision: 1.3 $)
   3  *
   4  * Copyright (c) 2002, 2005 Ducrot Bruno
   5  * Copyright (c) 2005 Rich Townsend (tiny hacks & tweaks)
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation version 2.
  10  */
  11
  12 #include <linux/version.h>
  13 #include <linux/module.h>
  14 #include <linux/slab.h>
  15 #include <linux/kernel.h>
  16 #include <linux/stddef.h>
  17 #include <linux/init.h>
  18 #include <linux/i2c.h>
  19 #include <linux/acpi.h>
  20 #include <linux/delay.h>
  21
  22 #include "i2c_ec.h"
  23
  24 #define xudelay(t)      udelay(t)
  25 #define xmsleep(t)      msleep(t)
  26
  27 #define ACPI_EC_HC_COMPONENT    0x00080000
  28 #define ACPI_EC_HC_CLASS        "ec_hc_smbus"
  29 #define ACPI_EC_HC_HID          "ACPI0001"
  30 #define ACPI_EC_HC_DEVICE_NAME  "EC HC smbus"
  31
  32 #define _COMPONENT              ACPI_EC_HC_COMPONENT
  33
  34 ACPI_MODULE_NAME("i2c_ec");
  35
  36 static int acpi_ec_hc_add(struct acpi_device *device);
  37 static int acpi_ec_hc_remove(struct acpi_device *device, int type);
  38
  39 static struct acpi_driver acpi_ec_hc_driver = {
  40         .name = "i2c_ec",
  41         .class = ACPI_EC_HC_CLASS,
  42         .ids = ACPI_EC_HC_HID,
  43         .ops = {
  44                 .add = acpi_ec_hc_add,
  45                 .remove = acpi_ec_hc_remove,
  46                 },
  47 };
  48
  49 /* Various bit mask for EC_SC (R) */
  50 #define OBF             0x01
  51 #define IBF             0x02
  52 #define CMD             0x08
  53 #define BURST           0x10
  54 #define SCI_EVT         0x20
  55 #define SMI_EVT         0x40
  56
  57 /* Commands for EC_SC (W) */
  58 #define RD_EC           0x80
  59 #define WR_EC           0x81
  60 #define BE_EC           0x82
  61 #define BD_EC           0x83
  62 #define QR_EC           0x84
  63
  64 /*
  65  * ACPI 2.0 chapter 13 SMBus 2.0 EC register model
  66  */
  67
  68 #define ACPI_EC_SMB_PRTCL       0x00    /* protocol, PEC */
  69 #define ACPI_EC_SMB_STS         0x01    /* status */
  70 #define ACPI_EC_SMB_ADDR        0x02    /* address */
  71 #define ACPI_EC_SMB_CMD         0x03    /* command */
  72 #define ACPI_EC_SMB_DATA        0x04    /* 32 data registers */
  73 #define ACPI_EC_SMB_BCNT        0x24    /* number of data bytes */
  74 #define ACPI_EC_SMB_ALRM_A      0x25    /* alarm address */
  75 #define ACPI_EC_SMB_ALRM_D      0x26    /* 2 bytes alarm data */
  76
  77 #define ACPI_EC_SMB_STS_DONE    0x80
  78 #define ACPI_EC_SMB_STS_ALRM    0x40
  79 #define ACPI_EC_SMB_STS_RES     0x20
  80 #define ACPI_EC_SMB_STS_STATUS  0x1f
  81
  82 #define ACPI_EC_SMB_STATUS_OK           0x00
  83 #define ACPI_EC_SMB_STATUS_FAIL         0x07
  84 #define ACPI_EC_SMB_STATUS_DNAK         0x10
  85 #define ACPI_EC_SMB_STATUS_DERR         0x11
  86 #define ACPI_EC_SMB_STATUS_CMD_DENY     0x12
  87 #define ACPI_EC_SMB_STATUS_UNKNOWN      0x13
  88 #define ACPI_EC_SMB_STATUS_ACC_DENY     0x17
  89 #define ACPI_EC_SMB_STATUS_TIMEOUT      0x18
  90 #define ACPI_EC_SMB_STATUS_NOTSUP       0x19
  91 #define ACPI_EC_SMB_STATUS_BUSY         0x1A
  92 #define ACPI_EC_SMB_STATUS_PEC          0x1F
  93
  94 #define ACPI_EC_SMB_PRTCL_WRITE                 0x00
  95 #define ACPI_EC_SMB_PRTCL_READ                  0x01
  96 #define ACPI_EC_SMB_PRTCL_QUICK                 0x02
  97 #define ACPI_EC_SMB_PRTCL_BYTE                  0x04
  98 #define ACPI_EC_SMB_PRTCL_BYTE_DATA             0x06
  99 #define ACPI_EC_SMB_PRTCL_WORD_DATA             0x08
 100 #define ACPI_EC_SMB_PRTCL_BLOCK_DATA            0x0a
 101 #define ACPI_EC_SMB_PRTCL_PROC_CALL             0x0c
 102 #define ACPI_EC_SMB_PRTCL_BLOCK_PROC_CALL       0x0d
 103 #define ACPI_EC_SMB_PRTCL_I2C_BLOCK_DATA        0x4a
 104 #define ACPI_EC_SMB_PRTCL_PEC                   0x80
 105
 106 /* Length of pre/post transaction sleep (msec) */
 107 #define ACPI_EC_SMB_TRANSACTION_SLEEP           1
 108 #define ACPI_EC_SMB_ACCESS_SLEEP1               1
 109 #define ACPI_EC_SMB_ACCESS_SLEEP2               10
 110
 111 static int acpi_ec_smb_read(struct acpi_ec_smbus *smbus, u8 address, u8 * data)
 112 {
 113         u8 val;
 114         int err;
 115
 116         err = ec_read(smbus->base + address, &val);
 117         if (!err) {
 118                 *data = val;
 119         }
 120         xmsleep(ACPI_EC_SMB_TRANSACTION_SLEEP);
 121         return (err);
 122 }
 123
 124 static int acpi_ec_smb_write(struct acpi_ec_smbus *smbus, u8 address, u8 data)
 125 {
 126         int err;
 127
 128         err = ec_write(smbus->base + address, data);
 129         return (err);
 130 }
 131
 132 static int
 133 acpi_ec_smb_access(struct i2c_adapter *adap, u16 addr, unsigned short flags,
 134                    char read_write, u8 command, int size,
 135                    union i2c_smbus_data *data)
 136 {
 137         struct acpi_ec_smbus *smbus = adap->algo_data;
 138         unsigned char protocol, len = 0, pec, temp[2] = { 0, 0 };
 139         int i;
 140
 141         if (read_write == I2C_SMBUS_READ) {
 142                 protocol = ACPI_EC_SMB_PRTCL_READ;
 143         } else {
 144                 protocol = ACPI_EC_SMB_PRTCL_WRITE;
 145         }
 146         pec = (flags & I2C_CLIENT_PEC) ? ACPI_EC_SMB_PRTCL_PEC : 0;
 147
 148         switch (size) {
 149
 150         case I2C_SMBUS_QUICK:
 151                 protocol |= ACPI_EC_SMB_PRTCL_QUICK;
 152                 read_write = I2C_SMBUS_WRITE;
 153                 break;
 154
 155         case I2C_SMBUS_BYTE:
 156                 if (read_write == I2C_SMBUS_WRITE) {
 157                         acpi_ec_smb_write(smbus, ACPI_EC_SMB_DATA, data->byte);
 158                 }
 159                 protocol |= ACPI_EC_SMB_PRTCL_BYTE;
 160                 break;
 161
 162         case I2C_SMBUS_BYTE_DATA:
 163                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_CMD, command);
 164                 if (read_write == I2C_SMBUS_WRITE) {
 165                         acpi_ec_smb_write(smbus, ACPI_EC_SMB_DATA, data->byte);
 166                 }
 167                 protocol |= ACPI_EC_SMB_PRTCL_BYTE_DATA;
 168                 break;
 169
 170         case I2C_SMBUS_WORD_DATA:
 171                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_CMD, command);
 172                 if (read_write == I2C_SMBUS_WRITE) {
 173                         acpi_ec_smb_write(smbus, ACPI_EC_SMB_DATA, data->word);
 174                         acpi_ec_smb_write(smbus, ACPI_EC_SMB_DATA + 1,
 175                                           data->word >> 8);
 176                 }
 177                 protocol |= ACPI_EC_SMB_PRTCL_WORD_DATA | pec;
 178                 break;
 179
 180         case I2C_SMBUS_BLOCK_DATA:
 181                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_CMD, command);
 182                 if (read_write == I2C_SMBUS_WRITE) {
 183                         len = min_t(u8, data->block[0], 32);
 184                         acpi_ec_smb_write(smbus, ACPI_EC_SMB_BCNT, len);
 185                         for (i = 0; i < len; i++)
 186                                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_DATA + i,
 187                                                   data->block[i + 1]);
 188                 }
 189                 protocol |= ACPI_EC_SMB_PRTCL_BLOCK_DATA | pec;
 190                 break;
 191
 192         case I2C_SMBUS_I2C_BLOCK_DATA:
 193                 len = min_t(u8, data->block[0], 32);
 194                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_CMD, command);
 195                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_BCNT, len);
 196                 if (read_write == I2C_SMBUS_WRITE) {
 197                         for (i = 0; i < len; i++) {
 198                                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_DATA + i,
 199                                                   data->block[i + 1]);
 200                         }
 201                 }
 202                 protocol |= ACPI_EC_SMB_PRTCL_I2C_BLOCK_DATA;
 203                 break;
 204
 205         case I2C_SMBUS_PROC_CALL:
 206                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_CMD, command);
 207                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_DATA, data->word);
 208                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_DATA + 1, data->word >> 8);
 209                 protocol = ACPI_EC_SMB_PRTCL_PROC_CALL | pec;
 210                 read_write = I2C_SMBUS_READ;
 211                 break;
 212
 213         case I2C_SMBUS_BLOCK_PROC_CALL:
 214                 protocol |= pec;
 215                 len = min_t(u8, data->block[0], 31);
 216                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_CMD, command);
 217                 acpi_ec_smb_write(smbus, ACPI_EC_SMB_BCNT, len);
 218                 for (i = 0; i < len; i++)
 219                         acpi_ec_smb_write(smbus, ACPI_EC_SMB_DATA + i,
 220                                           data->block[i + 1]);
 221                 protocol = ACPI_EC_SMB_PRTCL_BLOCK_PROC_CALL | pec;
 222                 read_write = I2C_SMBUS_READ;
 223                 break;
 224
 225         default:
 226                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "EC SMBus adapter: "
 227                                   "Unsupported transaction %d\n", size));
 228                 return (-1);
 229         }
 230
 231         acpi_ec_smb_write(smbus, ACPI_EC_SMB_ADDR, addr << 1);
 232         acpi_ec_smb_write(smbus, ACPI_EC_SMB_PRTCL, protocol);
 233
 234         acpi_ec_smb_read(smbus, ACPI_EC_SMB_STS, temp + 0);
 235
 236         if (~temp[0] & ACPI_EC_SMB_STS_DONE) {
 237                 xudelay(500);
 238                 acpi_ec_smb_read(smbus, ACPI_EC_SMB_STS, temp + 0);
 239         }
 240         if (~temp[0] & ACPI_EC_SMB_STS_DONE) {
 241                 xmsleep(ACPI_EC_SMB_ACCESS_SLEEP2);
 242                 acpi_ec_smb_read(smbus, ACPI_EC_SMB_STS, temp + 0);
 243         }
 244         if ((~temp[0] & ACPI_EC_SMB_STS_DONE)
 245             || (temp[0] & ACPI_EC_SMB_STS_STATUS)) {
 246                 return (-1);
 247         }
 248
 249         if (read_write == I2C_SMBUS_WRITE) {
 250                 return (0);
 251         }
 252
 253         switch (size) {
 254
 255         case I2C_SMBUS_BYTE:
 256         case I2C_SMBUS_BYTE_DATA:
 257                 acpi_ec_smb_read(smbus, ACPI_EC_SMB_DATA, &data->byte);
 258                 break;
 259
 260         case I2C_SMBUS_WORD_DATA:
 261         case I2C_SMBUS_PROC_CALL:
 262                 acpi_ec_smb_read(smbus, ACPI_EC_SMB_DATA, temp + 0);
 263                 acpi_ec_smb_read(smbus, ACPI_EC_SMB_DATA + 1, temp + 1);
 264                 data->word = (temp[1] << 8) | temp[0];
 265                 break;
 266
 267         case I2C_SMBUS_BLOCK_DATA:
 268         case I2C_SMBUS_BLOCK_PROC_CALL:
 269                 len = 0;
 270                 acpi_ec_smb_read(smbus, ACPI_EC_SMB_BCNT, &len);
 271                 len = min_t(u8, len, 32);
 272         case I2C_SMBUS_I2C_BLOCK_DATA:
 273                 for (i = 0; i < len; i++)
 274                         acpi_ec_smb_read(smbus, ACPI_EC_SMB_DATA + i,
 275                                          data->block + i + 1);
 276                 data->block[0] = len;
 277                 break;
 278         }
 279
 280         return (0);
 281 }
 282
 283 static u32 acpi_ec_smb_func(struct i2c_adapter *adapter)
 284 {
 285
 286         return (I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 287                 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 288                 I2C_FUNC_SMBUS_BLOCK_DATA |
 289                 I2C_FUNC_SMBUS_PROC_CALL |
 290                 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
 291                 I2C_FUNC_SMBUS_I2C_BLOCK | I2C_FUNC_SMBUS_HWPEC_CALC);
 292 }
 293
 294 static const struct i2c_algorithm acpi_ec_smbus_algorithm = {
 295         .smbus_xfer = acpi_ec_smb_access,
 296         .functionality = acpi_ec_smb_func,
 297 };
 298
 299 static int acpi_ec_hc_add(struct acpi_device *device)
 300 {
 301         int status;
 302         unsigned long val;
 303         struct acpi_ec_hc *ec_hc;
 304         struct acpi_ec_smbus *smbus;
 305
 306         if (!device) {
 307                 return -EINVAL;
 308         }
 309
 310         ec_hc = kzalloc(sizeof(struct acpi_ec_hc), GFP_KERNEL);
 311         if (!ec_hc) {
 312                 return -ENOMEM;
 313         }
 314
 315         smbus = kzalloc(sizeof(struct acpi_ec_smbus), GFP_KERNEL);
 316         if (!smbus) {
 317                 kfree(ec_hc);
 318                 return -ENOMEM;
 319         }
 320
 321         ec_hc->handle = device->handle;
 322         strcpy(acpi_device_name(device), ACPI_EC_HC_DEVICE_NAME);
 323         strcpy(acpi_device_class(device), ACPI_EC_HC_CLASS);
 324         acpi_driver_data(device) = ec_hc;
 325
 326         status = acpi_evaluate_integer(ec_hc->handle, "_EC", NULL, &val);
 327         if (ACPI_FAILURE(status)) {
 328                 ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Error obtaining _EC\n"));
 329                 kfree(ec_hc);
 330                 kfree(smbus);
 331                 return -EIO;
 332         }
 333
 334         smbus->ec = acpi_driver_data(device->parent);
 335         smbus->base = (val & 0xff00ull) >> 8;
 336         smbus->alert = val & 0xffull;
 337
 338         smbus->adapter.owner = THIS_MODULE;
 339         smbus->adapter.algo = &acpi_ec_smbus_algorithm;
 340         smbus->adapter.algo_data = smbus;
 341         smbus->adapter.dev.parent = &device->dev;
 342
 343         if (i2c_add_adapter(&smbus->adapter)) {
 344                 ACPI_DEBUG_PRINT((ACPI_DB_WARN,
 345                                   "EC SMBus adapter: Failed to register adapter\n"));
 346                 kfree(smbus);
 347                 kfree(ec_hc);
 348                 return -EIO;
 349         }
 350
 351         ec_hc->smbus = smbus;
 352
 353         printk(KERN_INFO PREFIX "%s [%s]\n",
 354                acpi_device_name(device), acpi_device_bid(device));
 355
 356         return AE_OK;
 357 }
 358
 359 static int acpi_ec_hc_remove(struct acpi_device *device, int type)
 360 {
 361         struct acpi_ec_hc *ec_hc;
 362
 363         if (!device) {
 364                 return -EINVAL;
 365         }
 366         ec_hc = acpi_driver_data(device);
 367
 368         i2c_del_adapter(&ec_hc->smbus->adapter);
 369         kfree(ec_hc->smbus);
 370         kfree(ec_hc);
 371
 372         return AE_OK;
 373 }
 374
 375 static int __init acpi_ec_hc_init(void)
 376 {
 377         int result;
 378
 379         result = acpi_bus_register_driver(&acpi_ec_hc_driver);
 380         if (result < 0) {
 381                 return -ENODEV;
 382         }
 383         return 0;
 384 }
 385
 386 static void __exit acpi_ec_hc_exit(void)
 387 {
 388         acpi_bus_unregister_driver(&acpi_ec_hc_driver);
 389 }
 390
 391 struct acpi_ec_hc *acpi_get_ec_hc(struct acpi_device *device)
 392 {
 393         return acpi_driver_data(device->parent);
 394 }
 395
 396 EXPORT_SYMBOL(acpi_get_ec_hc);
 397
 398 module_init(acpi_ec_hc_init);
 399 module_exit(acpi_ec_hc_exit);
 400
 401 MODULE_LICENSE("GPL");
 402 MODULE_AUTHOR("Ducrot Bruno");
 403 MODULE_DESCRIPTION("ACPI EC SMBus driver");