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