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 <linux/wait.h> 14 #include <linux/slab.h> 15 #include <linux/delay.h> 16 #include <linux/module.h> 17 #include <linux/interrupt.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, int type); 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 inline int smb_check_done(struct acpi_smb_hc *hc) 102 { 103 union acpi_smb_status status = {.raw = 0}; 104 smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw); 105 return status.fields.done && (status.fields.status == SMBUS_OK); 106 } 107 108 static int wait_transaction_complete(struct acpi_smb_hc *hc, int timeout) 109 { 110 if (wait_event_timeout(hc->wait, smb_check_done(hc), 111 msecs_to_jiffies(timeout))) 112 return 0; 113 /* 114 * After the timeout happens, OS will try to check the status of SMbus. 115 * If the status is what OS expected, it will be regarded as the bogus 116 * timeout. 117 */ 118 if (smb_check_done(hc)) 119 return 0; 120 else 121 return -ETIME; 122 } 123 124 static int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol, 125 u8 address, u8 command, u8 *data, u8 length) 126 { 127 int ret = -EFAULT, i; 128 u8 temp, sz = 0; 129 130 if (!hc) { 131 printk(KERN_ERR PREFIX "host controller is not configured\n"); 132 return ret; 133 } 134 135 mutex_lock(&hc->lock); 136 if (smb_hc_read(hc, ACPI_SMB_PROTOCOL, &temp)) 137 goto end; 138 if (temp) { 139 ret = -EBUSY; 140 goto end; 141 } 142 smb_hc_write(hc, ACPI_SMB_COMMAND, command); 143 if (!(protocol & 0x01)) { 144 smb_hc_write(hc, ACPI_SMB_BLOCK_COUNT, length); 145 for (i = 0; i < length; ++i) 146 smb_hc_write(hc, ACPI_SMB_DATA + i, data[i]); 147 } 148 smb_hc_write(hc, ACPI_SMB_ADDRESS, address << 1); 149 smb_hc_write(hc, ACPI_SMB_PROTOCOL, protocol); 150 /* 151 * Wait for completion. Save the status code, data size, 152 * and data into the return package (if required by the protocol). 153 */ 154 ret = wait_transaction_complete(hc, 1000); 155 if (ret || !(protocol & 0x01)) 156 goto end; 157 switch (protocol) { 158 case SMBUS_RECEIVE_BYTE: 159 case SMBUS_READ_BYTE: 160 sz = 1; 161 break; 162 case SMBUS_READ_WORD: 163 sz = 2; 164 break; 165 case SMBUS_READ_BLOCK: 166 if (smb_hc_read(hc, ACPI_SMB_BLOCK_COUNT, &sz)) { 167 ret = -EFAULT; 168 goto end; 169 } 170 sz &= 0x1f; 171 break; 172 } 173 for (i = 0; i < sz; ++i) 174 smb_hc_read(hc, ACPI_SMB_DATA + i, &data[i]); 175 end: 176 mutex_unlock(&hc->lock); 177 return ret; 178 } 179 180 int acpi_smbus_read(struct acpi_smb_hc *hc, u8 protocol, u8 address, 181 u8 command, u8 *data) 182 { 183 return acpi_smbus_transaction(hc, protocol, address, command, data, 0); 184 } 185 186 EXPORT_SYMBOL_GPL(acpi_smbus_read); 187 188 int acpi_smbus_write(struct acpi_smb_hc *hc, u8 protocol, u8 address, 189 u8 command, u8 *data, u8 length) 190 { 191 return acpi_smbus_transaction(hc, protocol, address, command, data, length); 192 } 193 194 EXPORT_SYMBOL_GPL(acpi_smbus_write); 195 196 int acpi_smbus_register_callback(struct acpi_smb_hc *hc, 197 smbus_alarm_callback callback, void *context) 198 { 199 mutex_lock(&hc->lock); 200 hc->callback = callback; 201 hc->context = context; 202 mutex_unlock(&hc->lock); 203 return 0; 204 } 205 206 EXPORT_SYMBOL_GPL(acpi_smbus_register_callback); 207 208 int acpi_smbus_unregister_callback(struct acpi_smb_hc *hc) 209 { 210 mutex_lock(&hc->lock); 211 hc->callback = NULL; 212 hc->context = NULL; 213 mutex_unlock(&hc->lock); 214 return 0; 215 } 216 217 EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback); 218 219 static inline void acpi_smbus_callback(void *context) 220 { 221 struct acpi_smb_hc *hc = context; 222 if (hc->callback) 223 hc->callback(hc->context); 224 } 225 226 static int smbus_alarm(void *context) 227 { 228 struct acpi_smb_hc *hc = context; 229 union acpi_smb_status status; 230 u8 address; 231 if (smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw)) 232 return 0; 233 /* Check if it is only a completion notify */ 234 if (status.fields.done) 235 wake_up(&hc->wait); 236 if (!status.fields.alarm) 237 return 0; 238 mutex_lock(&hc->lock); 239 smb_hc_read(hc, ACPI_SMB_ALARM_ADDRESS, &address); 240 status.fields.alarm = 0; 241 smb_hc_write(hc, ACPI_SMB_STATUS, status.raw); 242 /* We are only interested in events coming from known devices */ 243 switch (address >> 1) { 244 case ACPI_SBS_CHARGER: 245 case ACPI_SBS_MANAGER: 246 case ACPI_SBS_BATTERY: 247 acpi_os_execute(OSL_NOTIFY_HANDLER, 248 acpi_smbus_callback, hc); 249 default:; 250 } 251 mutex_unlock(&hc->lock); 252 return 0; 253 } 254 255 typedef int (*acpi_ec_query_func) (void *data); 256 257 extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit, 258 acpi_handle handle, acpi_ec_query_func func, 259 void *data); 260 261 static int acpi_smbus_hc_add(struct acpi_device *device) 262 { 263 int status; 264 unsigned long long val; 265 struct acpi_smb_hc *hc; 266 267 if (!device) 268 return -EINVAL; 269 270 status = acpi_evaluate_integer(device->handle, "_EC", NULL, &val); 271 if (ACPI_FAILURE(status)) { 272 printk(KERN_ERR PREFIX "error obtaining _EC.\n"); 273 return -EIO; 274 } 275 276 strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME); 277 strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS); 278 279 hc = kzalloc(sizeof(struct acpi_smb_hc), GFP_KERNEL); 280 if (!hc) 281 return -ENOMEM; 282 mutex_init(&hc->lock); 283 init_waitqueue_head(&hc->wait); 284 285 hc->ec = acpi_driver_data(device->parent); 286 hc->offset = (val >> 8) & 0xff; 287 hc->query_bit = val & 0xff; 288 device->driver_data = hc; 289 290 acpi_ec_add_query_handler(hc->ec, hc->query_bit, NULL, smbus_alarm, hc); 291 printk(KERN_INFO PREFIX "SBS HC: EC = 0x%p, offset = 0x%0x, query_bit = 0x%0x\n", 292 hc->ec, hc->offset, hc->query_bit); 293 294 return 0; 295 } 296 297 extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit); 298 299 static int acpi_smbus_hc_remove(struct acpi_device *device, int type) 300 { 301 struct acpi_smb_hc *hc; 302 303 if (!device) 304 return -EINVAL; 305 306 hc = acpi_driver_data(device); 307 acpi_ec_remove_query_handler(hc->ec, hc->query_bit); 308 kfree(hc); 309 device->driver_data = NULL; 310 return 0; 311 } 312 313 module_acpi_driver(acpi_smb_hc_driver); 314 315 MODULE_LICENSE("GPL"); 316 MODULE_AUTHOR("Alexey Starikovskiy"); 317 MODULE_DESCRIPTION("ACPI SMBus HC driver"); 318