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