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