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 "sbshc.h"
  18
  19 #define PREFIX "ACPI: "
  20
  21 #define ACPI_SMB_HC_CLASS       "smbus_host_ctl"
  22 #define ACPI_SMB_HC_DEVICE_NAME "ACPI SMBus HC"
  23
  24 struct acpi_smb_hc {
  25         struct acpi_ec *ec;
  26         struct mutex lock;
  27         wait_queue_head_t wait;
  28         u8 offset;
  29         u8 query_bit;
  30         smbus_alarm_callback callback;
  31         void *context;
  32         bool done;
  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 inline int smb_hc_read(struct acpi_smb_hc *hc, u8 address, u8 *data)
  92 {
  93         return ec_read(hc->offset + address, data);
  94 }
  95
  96 static inline int smb_hc_write(struct acpi_smb_hc *hc, u8 address, u8 data)
  97 {
  98         return ec_write(hc->offset + address, data);
  99 }
 100
 101 static int wait_transaction_complete(struct acpi_smb_hc *hc, int timeout)
 102 {
 103         if (wait_event_timeout(hc->wait, hc->done, msecs_to_jiffies(timeout)))
 104                 return 0;
 105         return -ETIME;
 106 }
 107
 108 static int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol,
 109                                   u8 address, u8 command, u8 *data, u8 length)
 110 {
 111         int ret = -EFAULT, i;
 112         u8 temp, sz = 0;
 113
 114         if (!hc) {
 115                 printk(KERN_ERR PREFIX "host controller is not configured\n");
 116                 return ret;
 117         }
 118
 119         mutex_lock(&hc->lock);
 120         hc->done = false;
 121         if (smb_hc_read(hc, ACPI_SMB_PROTOCOL, &temp))
 122                 goto end;
 123         if (temp) {
 124                 ret = -EBUSY;
 125                 goto end;
 126         }
 127         smb_hc_write(hc, ACPI_SMB_COMMAND, command);
 128         if (!(protocol & 0x01)) {
 129                 smb_hc_write(hc, ACPI_SMB_BLOCK_COUNT, length);
 130                 for (i = 0; i < length; ++i)
 131                         smb_hc_write(hc, ACPI_SMB_DATA + i, data[i]);
 132         }
 133         smb_hc_write(hc, ACPI_SMB_ADDRESS, address << 1);
 134         smb_hc_write(hc, ACPI_SMB_PROTOCOL, protocol);
 135         /*
 136          * Wait for completion. Save the status code, data size,
 137          * and data into the return package (if required by the protocol).
 138          */
 139         ret = wait_transaction_complete(hc, 1000);
 140         if (ret || !(protocol & 0x01))
 141                 goto end;
 142         switch (protocol) {
 143         case SMBUS_RECEIVE_BYTE:
 144         case SMBUS_READ_BYTE:
 145                 sz = 1;
 146                 break;
 147         case SMBUS_READ_WORD:
 148                 sz = 2;
 149                 break;
 150         case SMBUS_READ_BLOCK:
 151                 if (smb_hc_read(hc, ACPI_SMB_BLOCK_COUNT, &sz)) {
 152                         ret = -EFAULT;
 153                         goto end;
 154                 }
 155                 sz &= 0x1f;
 156                 break;
 157         }
 158         for (i = 0; i < sz; ++i)
 159                 smb_hc_read(hc, ACPI_SMB_DATA + i, &data[i]);
 160       end:
 161         mutex_unlock(&hc->lock);
 162         return ret;
 163 }
 164
 165 int acpi_smbus_read(struct acpi_smb_hc *hc, u8 protocol, u8 address,
 166                     u8 command, u8 *data)
 167 {
 168         return acpi_smbus_transaction(hc, protocol, address, command, data, 0);
 169 }
 170
 171 EXPORT_SYMBOL_GPL(acpi_smbus_read);
 172
 173 int acpi_smbus_write(struct acpi_smb_hc *hc, u8 protocol, u8 address,
 174                      u8 command, u8 *data, u8 length)
 175 {
 176         return acpi_smbus_transaction(hc, protocol, address, command, data, length);
 177 }
 178
 179 EXPORT_SYMBOL_GPL(acpi_smbus_write);
 180
 181 int acpi_smbus_register_callback(struct acpi_smb_hc *hc,
 182                                  smbus_alarm_callback callback, void *context)
 183 {
 184         mutex_lock(&hc->lock);
 185         hc->callback = callback;
 186         hc->context = context;
 187         mutex_unlock(&hc->lock);
 188         return 0;
 189 }
 190
 191 EXPORT_SYMBOL_GPL(acpi_smbus_register_callback);
 192
 193 int acpi_smbus_unregister_callback(struct acpi_smb_hc *hc)
 194 {
 195         mutex_lock(&hc->lock);
 196         hc->callback = NULL;
 197         hc->context = NULL;
 198         mutex_unlock(&hc->lock);
 199         return 0;
 200 }
 201
 202 EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback);
 203
 204 static inline void acpi_smbus_callback(void *context)
 205 {
 206         struct acpi_smb_hc *hc = context;
 207         if (hc->callback)
 208                 hc->callback(hc->context);
 209 }
 210
 211 static int smbus_alarm(void *context)
 212 {
 213         struct acpi_smb_hc *hc = context;
 214         union acpi_smb_status status;
 215         u8 address;
 216         if (smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw))
 217                 return 0;
 218         /* Check if it is only a completion notify */
 219         if (status.fields.done && status.fields.status == SMBUS_OK) {
 220                 hc->done = true;
 221                 wake_up(&hc->wait);
 222         }
 223         if (!status.fields.alarm)
 224                 return 0;
 225         mutex_lock(&hc->lock);
 226         smb_hc_read(hc, ACPI_SMB_ALARM_ADDRESS, &address);
 227         status.fields.alarm = 0;
 228         smb_hc_write(hc, ACPI_SMB_STATUS, status.raw);
 229         /* We are only interested in events coming from known devices */
 230         switch (address >> 1) {
 231                 case ACPI_SBS_CHARGER:
 232                 case ACPI_SBS_MANAGER:
 233                 case ACPI_SBS_BATTERY:
 234                         acpi_os_execute(OSL_NOTIFY_HANDLER,
 235                                         acpi_smbus_callback, hc);
 236                 default:;
 237         }
 238         mutex_unlock(&hc->lock);
 239         return 0;
 240 }
 241
 242 typedef int (*acpi_ec_query_func) (void *data);
 243
 244 extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
 245                               acpi_handle handle, acpi_ec_query_func func,
 246                               void *data);
 247
 248 static int acpi_smbus_hc_add(struct acpi_device *device)
 249 {
 250         int status;
 251         unsigned long long val;
 252         struct acpi_smb_hc *hc;
 253
 254         if (!device)
 255                 return -EINVAL;
 256
 257         status = acpi_evaluate_integer(device->handle, "_EC", NULL, &val);
 258         if (ACPI_FAILURE(status)) {
 259                 printk(KERN_ERR PREFIX "error obtaining _EC.\n");
 260                 return -EIO;
 261         }
 262
 263         strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME);
 264         strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS);
 265
 266         hc = kzalloc(sizeof(struct acpi_smb_hc), GFP_KERNEL);
 267         if (!hc)
 268                 return -ENOMEM;
 269         mutex_init(&hc->lock);
 270         init_waitqueue_head(&hc->wait);
 271
 272         hc->ec = acpi_driver_data(device->parent);
 273         hc->offset = (val >> 8) & 0xff;
 274         hc->query_bit = val & 0xff;
 275         device->driver_data = hc;
 276
 277         acpi_ec_add_query_handler(hc->ec, hc->query_bit, NULL, smbus_alarm, hc);
 278         printk(KERN_INFO PREFIX "SBS HC: EC = 0x%p, offset = 0x%0x, query_bit = 0x%0x\n",
 279                 hc->ec, hc->offset, hc->query_bit);
 280
 281         return 0;
 282 }
 283
 284 extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);
 285
 286 static int acpi_smbus_hc_remove(struct acpi_device *device)
 287 {
 288         struct acpi_smb_hc *hc;
 289
 290         if (!device)
 291                 return -EINVAL;
 292
 293         hc = acpi_driver_data(device);
 294         acpi_ec_remove_query_handler(hc->ec, hc->query_bit);
 295         kfree(hc);
 296         device->driver_data = NULL;
 297         return 0;
 298 }
 299
 300 module_acpi_driver(acpi_smb_hc_driver);
 301
 302 MODULE_LICENSE("GPL");
 303 MODULE_AUTHOR("Alexey Starikovskiy");
 304 MODULE_DESCRIPTION("ACPI SMBus HC driver");