drivers/acpi/sbshc.c

   1 /*
   2  * SMBus driver for ACPI Embedded Controller (v0.1)
   3  *
   4  * Copyright (c) 2007 Alexey Starikovskiy
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation version 2.
   9  */
  10
  11 #include <linux/acpi.h>
  12 #include <linux/wait.h>
  13 #include <linux/slab.h>
  14 #include <linux/delay.h>
  15 #include <linux/module.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/dmi.h>
  18 #include "sbshc.h"
  19
  20 #define PREFIX "ACPI: "
  21
  22 #define ACPI_SMB_HC_CLASS       "smbus_host_ctl"
  23 #define ACPI_SMB_HC_DEVICE_NAME "ACPI SMBus HC"
  24
  25 struct acpi_smb_hc {
  26         struct acpi_ec *ec;
  27         struct mutex lock;
  28         wait_queue_head_t wait;
  29         u8 offset;
  30         u8 query_bit;
  31         smbus_alarm_callback callback;
  32         void *context;
  33 };
  34
  35 static int acpi_smbus_hc_add(struct acpi_device *device);
  36 static int acpi_smbus_hc_remove(struct acpi_device *device);
  37
  38 static const struct acpi_device_id sbs_device_ids[] = {
  39         {"ACPI0001", 0},
  40         {"ACPI0005", 0},
  41         {"", 0},
  42 };
  43
  44 MODULE_DEVICE_TABLE(acpi, sbs_device_ids);
  45
  46 static struct acpi_driver acpi_smb_hc_driver = {
  47         .name = "smbus_hc",
  48         .class = ACPI_SMB_HC_CLASS,
  49         .ids = sbs_device_ids,
  50         .ops = {
  51                 .add = acpi_smbus_hc_add,
  52                 .remove = acpi_smbus_hc_remove,
  53                 },
  54 };
  55
  56 union acpi_smb_status {
  57         u8 raw;
  58         struct {
  59                 u8 status:5;
  60                 u8 reserved:1;
  61                 u8 alarm:1;
  62                 u8 done:1;
  63         } fields;
  64 };
  65
  66 enum acpi_smb_status_codes {
  67         SMBUS_OK = 0,
  68         SMBUS_UNKNOWN_FAILURE = 0x07,
  69         SMBUS_DEVICE_ADDRESS_NACK = 0x10,
  70         SMBUS_DEVICE_ERROR = 0x11,
  71         SMBUS_DEVICE_COMMAND_ACCESS_DENIED = 0x12,
  72         SMBUS_UNKNOWN_ERROR = 0x13,
  73         SMBUS_DEVICE_ACCESS_DENIED = 0x17,
  74         SMBUS_TIMEOUT = 0x18,
  75         SMBUS_HOST_UNSUPPORTED_PROTOCOL = 0x19,
  76         SMBUS_BUSY = 0x1a,
  77         SMBUS_PEC_ERROR = 0x1f,
  78 };
  79
  80 enum acpi_smb_offset {
  81         ACPI_SMB_PROTOCOL = 0,  /* protocol, PEC */
  82         ACPI_SMB_STATUS = 1,    /* status */
  83         ACPI_SMB_ADDRESS = 2,   /* address */
  84         ACPI_SMB_COMMAND = 3,   /* command */
  85         ACPI_SMB_DATA = 4,      /* 32 data registers */
  86         ACPI_SMB_BLOCK_COUNT = 0x24,    /* number of data bytes */
  87         ACPI_SMB_ALARM_ADDRESS = 0x25,  /* alarm address */
  88         ACPI_SMB_ALARM_DATA = 0x26,     /* 2 bytes alarm data */
  89 };
  90
  91 static bool macbook;
  92
  93 static inline int smb_hc_read(struct acpi_smb_hc *hc, u8 address, u8 *data)
  94 {
  95         return ec_read(hc->offset + address, data);
  96 }
  97
  98 static inline int smb_hc_write(struct acpi_smb_hc *hc, u8 address, u8 data)
  99 {
 100         return ec_write(hc->offset + address, data);
 101 }
 102
 103 static inline int smb_check_done(struct acpi_smb_hc *hc)
 104 {
 105         union acpi_smb_status status = {.raw = 0};
 106         smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw);
 107         return status.fields.done && (status.fields.status == SMBUS_OK);
 108 }
 109
 110 static int wait_transaction_complete(struct acpi_smb_hc *hc, int timeout)
 111 {
 112         if (wait_event_timeout(hc->wait, smb_check_done(hc),
 113                                msecs_to_jiffies(timeout)))
 114                 return 0;
 115         /*
 116          * After the timeout happens, OS will try to check the status of SMbus.
 117          * If the status is what OS expected, it will be regarded as the bogus
 118          * timeout.
 119          */
 120         if (smb_check_done(hc))
 121                 return 0;
 122         else
 123                 return -ETIME;
 124 }
 125
 126 static int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol,
 127                                   u8 address, u8 command, u8 *data, u8 length)
 128 {
 129         int ret = -EFAULT, i;
 130         u8 temp, sz = 0;
 131
 132         if (!hc) {
 133                 printk(KERN_ERR PREFIX "host controller is not configured\n");
 134                 return ret;
 135         }
 136
 137         mutex_lock(&hc->lock);
 138         if (macbook)
 139                 udelay(5);
 140         if (smb_hc_read(hc, ACPI_SMB_PROTOCOL, &temp))
 141                 goto end;
 142         if (temp) {
 143                 ret = -EBUSY;
 144                 goto end;
 145         }
 146         smb_hc_write(hc, ACPI_SMB_COMMAND, command);
 147         if (!(protocol & 0x01)) {
 148                 smb_hc_write(hc, ACPI_SMB_BLOCK_COUNT, length);
 149                 for (i = 0; i < length; ++i)
 150                         smb_hc_write(hc, ACPI_SMB_DATA + i, data[i]);
 151         }
 152         smb_hc_write(hc, ACPI_SMB_ADDRESS, address << 1);
 153         smb_hc_write(hc, ACPI_SMB_PROTOCOL, protocol);
 154         /*
 155          * Wait for completion. Save the status code, data size,
 156          * and data into the return package (if required by the protocol).
 157          */
 158         ret = wait_transaction_complete(hc, 1000);
 159         if (ret || !(protocol & 0x01))
 160                 goto end;
 161         switch (protocol) {
 162         case SMBUS_RECEIVE_BYTE:
 163         case SMBUS_READ_BYTE:
 164                 sz = 1;
 165                 break;
 166         case SMBUS_READ_WORD:
 167                 sz = 2;
 168                 break;
 169         case SMBUS_READ_BLOCK:
 170                 if (smb_hc_read(hc, ACPI_SMB_BLOCK_COUNT, &sz)) {
 171                         ret = -EFAULT;
 172                         goto end;
 173                 }
 174                 sz &= 0x1f;
 175                 break;
 176         }
 177         for (i = 0; i < sz; ++i)
 178                 smb_hc_read(hc, ACPI_SMB_DATA + i, &data[i]);
 179       end:
 180         mutex_unlock(&hc->lock);
 181         return ret;
 182 }
 183
 184 int acpi_smbus_read(struct acpi_smb_hc *hc, u8 protocol, u8 address,
 185                     u8 command, u8 *data)
 186 {
 187         return acpi_smbus_transaction(hc, protocol, address, command, data, 0);
 188 }
 189
 190 EXPORT_SYMBOL_GPL(acpi_smbus_read);
 191
 192 int acpi_smbus_write(struct acpi_smb_hc *hc, u8 protocol, u8 address,
 193                      u8 command, u8 *data, u8 length)
 194 {
 195         return acpi_smbus_transaction(hc, protocol, address, command, data, length);
 196 }
 197
 198 EXPORT_SYMBOL_GPL(acpi_smbus_write);
 199
 200 int acpi_smbus_register_callback(struct acpi_smb_hc *hc,
 201                                  smbus_alarm_callback callback, void *context)
 202 {
 203         mutex_lock(&hc->lock);
 204         hc->callback = callback;
 205         hc->context = context;
 206         mutex_unlock(&hc->lock);
 207         return 0;
 208 }
 209
 210 EXPORT_SYMBOL_GPL(acpi_smbus_register_callback);
 211
 212 int acpi_smbus_unregister_callback(struct acpi_smb_hc *hc)
 213 {
 214         mutex_lock(&hc->lock);
 215         hc->callback = NULL;
 216         hc->context = NULL;
 217         mutex_unlock(&hc->lock);
 218         return 0;
 219 }
 220
 221 EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback);
 222
 223 static inline void acpi_smbus_callback(void *context)
 224 {
 225         struct acpi_smb_hc *hc = context;
 226         if (hc->callback)
 227                 hc->callback(hc->context);
 228 }
 229
 230 static int smbus_alarm(void *context)
 231 {
 232         struct acpi_smb_hc *hc = context;
 233         union acpi_smb_status status;
 234         u8 address;
 235         if (smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw))
 236                 return 0;
 237         /* Check if it is only a completion notify */
 238         if (status.fields.done)
 239                 wake_up(&hc->wait);
 240         if (!status.fields.alarm)
 241                 return 0;
 242         mutex_lock(&hc->lock);
 243         smb_hc_read(hc, ACPI_SMB_ALARM_ADDRESS, &address);
 244         status.fields.alarm = 0;
 245         smb_hc_write(hc, ACPI_SMB_STATUS, status.raw);
 246         /* We are only interested in events coming from known devices */
 247         switch (address >> 1) {
 248                 case ACPI_SBS_CHARGER:
 249                 case ACPI_SBS_MANAGER:
 250                 case ACPI_SBS_BATTERY:
 251                         acpi_os_execute(OSL_NOTIFY_HANDLER,
 252                                         acpi_smbus_callback, hc);
 253                 default:;
 254         }
 255         mutex_unlock(&hc->lock);
 256         return 0;
 257 }
 258
 259 typedef int (*acpi_ec_query_func) (void *data);
 260
 261 extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 262                               acpi_handle handle, acpi_ec_query_func func,
 263                               void *data);
 264
 265 static int macbook_dmi_match(const struct dmi_system_id *d)
 266 {
 267         pr_debug("Detected MacBook, enabling workaround\n");
 268         macbook = true;
 269         return 0;
 270 }
 271
 272 static struct dmi_system_id acpi_smbus_dmi_table[] = {
 273         { macbook_dmi_match, "Apple MacBook", {
 274           DMI_MATCH(DMI_BOARD_VENDOR, "Apple"),
 275           DMI_MATCH(DMI_PRODUCT_NAME, "MacBook") },
 276         },
 277         { },
 278 };
 279
 280 static int acpi_smbus_hc_add(struct acpi_device *device)
 281 {
 282         int status;
 283         unsigned long long val;
 284         struct acpi_smb_hc *hc;
 285
 286         dmi_check_system(acpi_smbus_dmi_table);
 287
 288         if (!device)
 289                 return -EINVAL;
 290
 291         status = acpi_evaluate_integer(device->handle, "_EC", NULL, &val);
 292         if (ACPI_FAILURE(status)) {
 293                 printk(KERN_ERR PREFIX "error obtaining _EC.\n");
 294                 return -EIO;
 295         }
 296
 297         strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME);
 298         strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS);
 299
 300         hc = kzalloc(sizeof(struct acpi_smb_hc), GFP_KERNEL);
 301         if (!hc)
 302                 return -ENOMEM;
 303         mutex_init(&hc->lock);
 304         init_waitqueue_head(&hc->wait);
 305
 306         hc->ec = acpi_driver_data(device->parent);
 307         hc->offset = (val >> 8) & 0xff;
 308         hc->query_bit = val & 0xff;
 309         device->driver_data = hc;
 310
 311         acpi_ec_add_query_handler(hc->ec, hc->query_bit, NULL, smbus_alarm, hc);
 312         printk(KERN_INFO PREFIX "SBS HC: EC = 0x%p, offset = 0x%0x, query_bit = 0x%0x\n",
 313                 hc->ec, hc->offset, hc->query_bit);
 314
 315         return 0;
 316 }
 317
 318 extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);
 319
 320 static int acpi_smbus_hc_remove(struct acpi_device *device)
 321 {
 322         struct acpi_smb_hc *hc;
 323
 324         if (!device)
 325                 return -EINVAL;
 326
 327         hc = acpi_driver_data(device);
 328         acpi_ec_remove_query_handler(hc->ec, hc->query_bit);
 329         kfree(hc);
 330         device->driver_data = NULL;
 331         return 0;
 332 }
 333
 334 module_acpi_driver(acpi_smb_hc_driver);
 335
 336 MODULE_LICENSE("GPL");
 337 MODULE_AUTHOR("Alexey Starikovskiy");
 338 MODULE_DESCRIPTION("ACPI SMBus HC driver");