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 <acpi/acpi_bus.h> 12 #include <acpi/acpi_drivers.h> 13 #include <acpi/actypes.h> 14 #include <linux/wait.h> 15 #include <linux/delay.h> 16 #include <linux/interrupt.h> 17 #include "sbshc.h" 18 19 #define ACPI_SMB_HC_CLASS "smbus_host_controller" 20 #define ACPI_SMB_HC_DEVICE_NAME "ACPI SMBus HC" 21 22 struct acpi_smb_hc { 23 struct acpi_ec *ec; 24 struct mutex lock; 25 wait_queue_head_t wait; 26 u8 offset; 27 u8 query_bit; 28 smbus_alarm_callback callback; 29 void *context; 30 }; 31 32 static int acpi_smbus_hc_add(struct acpi_device *device); 33 static int acpi_smbus_hc_remove(struct acpi_device *device, int type); 34 35 static const struct acpi_device_id sbs_device_ids[] = { 36 {"ACPI0001", 0}, 37 {"ACPI0005", 0}, 38 {"", 0}, 39 }; 40 41 MODULE_DEVICE_TABLE(acpi, sbs_device_ids); 42 43 static struct acpi_driver acpi_smb_hc_driver = { 44 .name = "smbus_hc", 45 .class = ACPI_SMB_HC_CLASS, 46 .ids = sbs_device_ids, 47 .ops = { 48 .add = acpi_smbus_hc_add, 49 .remove = acpi_smbus_hc_remove, 50 }, 51 }; 52 53 union acpi_smb_status { 54 u8 raw; 55 struct { 56 u8 status:5; 57 u8 reserved:1; 58 u8 alarm:1; 59 u8 done:1; 60 } fields; 61 }; 62 63 enum acpi_smb_status_codes { 64 SMBUS_OK = 0, 65 SMBUS_UNKNOWN_FAILURE = 0x07, 66 SMBUS_DEVICE_ADDRESS_NACK = 0x10, 67 SMBUS_DEVICE_ERROR = 0x11, 68 SMBUS_DEVICE_COMMAND_ACCESS_DENIED = 0x12, 69 SMBUS_UNKNOWN_ERROR = 0x13, 70 SMBUS_DEVICE_ACCESS_DENIED = 0x17, 71 SMBUS_TIMEOUT = 0x18, 72 SMBUS_HOST_UNSUPPORTED_PROTOCOL = 0x19, 73 SMBUS_BUSY = 0x1a, 74 SMBUS_PEC_ERROR = 0x1f, 75 }; 76 77 enum acpi_smb_offset { 78 ACPI_SMB_PROTOCOL = 0, /* protocol, PEC */ 79 ACPI_SMB_STATUS = 1, /* status */ 80 ACPI_SMB_ADDRESS = 2, /* address */ 81 ACPI_SMB_COMMAND = 3, /* command */ 82 ACPI_SMB_DATA = 4, /* 32 data registers */ 83 ACPI_SMB_BLOCK_COUNT = 0x24, /* number of data bytes */ 84 ACPI_SMB_ALARM_ADDRESS = 0x25, /* alarm address */ 85 ACPI_SMB_ALARM_DATA = 0x26, /* 2 bytes alarm data */ 86 }; 87 88 static inline int smb_hc_read(struct acpi_smb_hc *hc, u8 address, u8 *data) 89 { 90 return ec_read(hc->offset + address, data); 91 } 92 93 static inline int smb_hc_write(struct acpi_smb_hc *hc, u8 address, u8 data) 94 { 95 return ec_write(hc->offset + address, data); 96 } 97 98 static inline int smb_check_done(struct acpi_smb_hc *hc) 99 { 100 union acpi_smb_status status = {.raw = 0}; 101 smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw); 102 return status.fields.done && (status.fields.status == SMBUS_OK); 103 } 104 105 static int wait_transaction_complete(struct acpi_smb_hc *hc, int timeout) 106 { 107 if (wait_event_timeout(hc->wait, smb_check_done(hc), 108 msecs_to_jiffies(timeout))) 109 return 0; 110 else 111 return -ETIME; 112 } 113 114 static int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol, 115 u8 address, u8 command, u8 *data, u8 length) 116 { 117 int ret = -EFAULT, i; 118 u8 temp, sz = 0; 119 120 if (!hc) { 121 printk(KERN_ERR PREFIX "host controller is not configured\n"); 122 return ret; 123 } 124 125 mutex_lock(&hc->lock); 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) 225 wake_up(&hc->wait); 226 if (!status.fields.alarm) 227 return 0; 228 mutex_lock(&hc->lock); 229 smb_hc_read(hc, ACPI_SMB_ALARM_ADDRESS, &address); 230 status.fields.alarm = 0; 231 smb_hc_write(hc, ACPI_SMB_STATUS, status.raw); 232 /* We are only interested in events coming from known devices */ 233 switch (address >> 1) { 234 case ACPI_SBS_CHARGER: 235 case ACPI_SBS_MANAGER: 236 case ACPI_SBS_BATTERY: 237 acpi_os_execute(OSL_GPE_HANDLER, 238 acpi_smbus_callback, hc); 239 default:; 240 } 241 mutex_unlock(&hc->lock); 242 return 0; 243 } 244 245 typedef int (*acpi_ec_query_func) (void *data); 246 247 extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit, 248 acpi_handle handle, acpi_ec_query_func func, 249 void *data); 250 251 static int acpi_smbus_hc_add(struct acpi_device *device) 252 { 253 int status; 254 unsigned long val; 255 struct acpi_smb_hc *hc; 256 257 if (!device) 258 return -EINVAL; 259 260 status = acpi_evaluate_integer(device->handle, "_EC", NULL, &val); 261 if (ACPI_FAILURE(status)) { 262 printk(KERN_ERR PREFIX "error obtaining _EC.\n"); 263 return -EIO; 264 } 265 266 strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME); 267 strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS); 268 269 hc = kzalloc(sizeof(struct acpi_smb_hc), GFP_KERNEL); 270 if (!hc) 271 return -ENOMEM; 272 mutex_init(&hc->lock); 273 init_waitqueue_head(&hc->wait); 274 275 hc->ec = acpi_driver_data(device->parent); 276 hc->offset = (val >> 8) & 0xff; 277 hc->query_bit = val & 0xff; 278 acpi_driver_data(device) = hc; 279 280 acpi_ec_add_query_handler(hc->ec, hc->query_bit, NULL, smbus_alarm, hc); 281 printk(KERN_INFO PREFIX "SBS HC: EC = 0x%p, offset = 0x%0x, query_bit = 0x%0x\n", 282 hc->ec, hc->offset, hc->query_bit); 283 284 return 0; 285 } 286 287 extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit); 288 289 static int acpi_smbus_hc_remove(struct acpi_device *device, int type) 290 { 291 struct acpi_smb_hc *hc; 292 293 if (!device) 294 return -EINVAL; 295 296 hc = acpi_driver_data(device); 297 acpi_ec_remove_query_handler(hc->ec, hc->query_bit); 298 kfree(hc); 299 acpi_driver_data(device) = NULL; 300 return 0; 301 } 302 303 static int __init acpi_smb_hc_init(void) 304 { 305 int result; 306 307 result = acpi_bus_register_driver(&acpi_smb_hc_driver); 308 if (result < 0) 309 return -ENODEV; 310 return 0; 311 } 312 313 static void __exit acpi_smb_hc_exit(void) 314 { 315 acpi_bus_unregister_driver(&acpi_smb_hc_driver); 316 } 317 318 module_init(acpi_smb_hc_init); 319 module_exit(acpi_smb_hc_exit); 320 321 MODULE_LICENSE("GPL"); 322 MODULE_AUTHOR("Alexey Starikovskiy"); 323 MODULE_DESCRIPTION("ACPI SMBus HC driver"); 324