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 acpi_os_wait_events_complete(); 200 return 0; 201 } 202 203 EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback); 204 205 static inline void acpi_smbus_callback(void *context) 206 { 207 struct acpi_smb_hc *hc = context; 208 if (hc->callback) 209 hc->callback(hc->context); 210 } 211 212 static int smbus_alarm(void *context) 213 { 214 struct acpi_smb_hc *hc = context; 215 union acpi_smb_status status; 216 u8 address; 217 if (smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw)) 218 return 0; 219 /* Check if it is only a completion notify */ 220 if (status.fields.done && status.fields.status == SMBUS_OK) { 221 hc->done = true; 222 wake_up(&hc->wait); 223 } 224 if (!status.fields.alarm) 225 return 0; 226 mutex_lock(&hc->lock); 227 smb_hc_read(hc, ACPI_SMB_ALARM_ADDRESS, &address); 228 status.fields.alarm = 0; 229 smb_hc_write(hc, ACPI_SMB_STATUS, status.raw); 230 /* We are only interested in events coming from known devices */ 231 switch (address >> 1) { 232 case ACPI_SBS_CHARGER: 233 case ACPI_SBS_MANAGER: 234 case ACPI_SBS_BATTERY: 235 acpi_os_execute(OSL_NOTIFY_HANDLER, 236 acpi_smbus_callback, hc); 237 default:; 238 } 239 mutex_unlock(&hc->lock); 240 return 0; 241 } 242 243 typedef int (*acpi_ec_query_func) (void *data); 244 245 extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit, 246 acpi_handle handle, acpi_ec_query_func func, 247 void *data); 248 249 static int acpi_smbus_hc_add(struct acpi_device *device) 250 { 251 int status; 252 unsigned long long val; 253 struct acpi_smb_hc *hc; 254 255 if (!device) 256 return -EINVAL; 257 258 status = acpi_evaluate_integer(device->handle, "_EC", NULL, &val); 259 if (ACPI_FAILURE(status)) { 260 printk(KERN_ERR PREFIX "error obtaining _EC.\n"); 261 return -EIO; 262 } 263 264 strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME); 265 strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS); 266 267 hc = kzalloc(sizeof(struct acpi_smb_hc), GFP_KERNEL); 268 if (!hc) 269 return -ENOMEM; 270 mutex_init(&hc->lock); 271 init_waitqueue_head(&hc->wait); 272 273 hc->ec = acpi_driver_data(device->parent); 274 hc->offset = (val >> 8) & 0xff; 275 hc->query_bit = val & 0xff; 276 device->driver_data = hc; 277 278 acpi_ec_add_query_handler(hc->ec, hc->query_bit, NULL, smbus_alarm, hc); 279 dev_info(&device->dev, "SBS HC: offset = 0x%0x, query_bit = 0x%0x\n", 280 hc->offset, hc->query_bit); 281 282 return 0; 283 } 284 285 extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit); 286 287 static int acpi_smbus_hc_remove(struct acpi_device *device) 288 { 289 struct acpi_smb_hc *hc; 290 291 if (!device) 292 return -EINVAL; 293 294 hc = acpi_driver_data(device); 295 acpi_ec_remove_query_handler(hc->ec, hc->query_bit); 296 acpi_os_wait_events_complete(); 297 kfree(hc); 298 device->driver_data = NULL; 299 return 0; 300 } 301 302 module_acpi_driver(acpi_smb_hc_driver); 303 304 MODULE_LICENSE("GPL"); 305 MODULE_AUTHOR("Alexey Starikovskiy"); 306 MODULE_DESCRIPTION("ACPI SMBus HC driver"); 307