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1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 | /* i2c-core.c - a device driver for the iic-bus interface */ /* ------------------------------------------------------------------------- */ /* Copyright (C) 1995-99 Simon G. Vogl This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* ------------------------------------------------------------------------- */ /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>. All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl> SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> */ /* $Id: i2c-core.c,v 1.95 2003/01/22 05:25:08 kmalkki Exp $ */ /* #define DEBUG 1 */ /* needed to pick up the dev_dbg() calls */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/errno.h> #include <linux/slab.h> #include <linux/i2c.h> #include <linux/init.h> #include <linux/seq_file.h> #include <asm/uaccess.h> #define DEB(x) if (i2c_debug>=1) x; #define DEB2(x) if (i2c_debug>=2) x; static LIST_HEAD(adapters); static LIST_HEAD(drivers); static DECLARE_MUTEX(core_lists); /**** debug level */ static int i2c_debug; int i2c_device_probe(struct device *dev) { return -ENODEV; } int i2c_device_remove(struct device *dev) { return 0; } static void i2c_adapter_dev_release(struct device *dev) { struct i2c_adapter *adap = dev_to_i2c_adapter(dev); complete(&adap->dev_released); } static struct device_driver i2c_adapter_driver = { .name = "i2c_adapter", .bus = &i2c_bus_type, .probe = i2c_device_probe, .remove = i2c_device_remove, }; static void i2c_adapter_class_dev_release(struct class_device *dev) { struct i2c_adapter *adap = class_dev_to_i2c_adapter(dev); complete(&adap->class_dev_released); } static struct class i2c_adapter_class = { .name = "i2c-adapter", .release = &i2c_adapter_class_dev_release, }; static ssize_t show_adapter_name(struct device *dev, char *buf) { struct i2c_adapter *adap = dev_to_i2c_adapter(dev); return sprintf(buf, "%s\n", adap->name); } static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL); static void i2c_client_release(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); complete(&client->released); } static ssize_t show_client_name(struct device *dev, char *buf) { struct i2c_client *client = to_i2c_client(dev); return sprintf(buf, "%s\n", client->name); } /* * We can't use the DEVICE_ATTR() macro here as we want the same filename for a * different type of a device. So beware if the DEVICE_ATTR() macro ever * changes, this definition will also have to change. */ static struct device_attribute dev_attr_client_name = { .attr = {.name = "name", .mode = S_IRUGO, .owner = THIS_MODULE }, .show = &show_client_name, }; /* --------------------------------------------------- * registering functions * --------------------------------------------------- */ /* ----- * i2c_add_adapter is called from within the algorithm layer, * when a new hw adapter registers. A new device is register to be * available for clients. */ int i2c_add_adapter(struct i2c_adapter *adap) { static int nr = 0; struct list_head *item; struct i2c_driver *driver; down(&core_lists); adap->nr = nr++; init_MUTEX(&adap->bus_lock); init_MUTEX(&adap->clist_lock); list_add_tail(&adap->list,&adapters); INIT_LIST_HEAD(&adap->clients); /* Add the adapter to the driver core. * If the parent pointer is not set up, * we add this adapter to the legacy bus. */ if (adap->dev.parent == NULL) adap->dev.parent = &legacy_bus; sprintf(adap->dev.bus_id, "i2c-%d", adap->nr); adap->dev.driver = &i2c_adapter_driver; adap->dev.release = &i2c_adapter_dev_release; device_register(&adap->dev); device_create_file(&adap->dev, &dev_attr_name); /* Add this adapter to the i2c_adapter class */ memset(&adap->class_dev, 0x00, sizeof(struct class_device)); adap->class_dev.dev = &adap->dev; adap->class_dev.class = &i2c_adapter_class; strlcpy(adap->class_dev.class_id, adap->dev.bus_id, BUS_ID_SIZE); class_device_register(&adap->class_dev); /* inform drivers of new adapters */ list_for_each(item,&drivers) { driver = list_entry(item, struct i2c_driver, list); if (driver->flags & I2C_DF_NOTIFY) /* We ignore the return code; if it fails, too bad */ driver->attach_adapter(adap); } up(&core_lists); DEB(dev_dbg(&adap->dev, "registered as adapter #%d\n", adap->nr)); return 0; } int i2c_del_adapter(struct i2c_adapter *adap) { struct list_head *item, *_n; struct i2c_driver *driver; struct i2c_client *client; int res = 0; down(&core_lists); list_for_each(item,&drivers) { driver = list_entry(item, struct i2c_driver, list); if (driver->detach_adapter) if ((res = driver->detach_adapter(adap))) { dev_warn(&adap->dev, "can't detach adapter" "while detaching driver %s: driver not " "detached!", driver->name); goto out_unlock; } } /* detach any active clients. This must be done first, because * it can fail; in which case we give upp. */ list_for_each_safe(item, _n, &adap->clients) { client = list_entry(item, struct i2c_client, list); /* detaching devices is unconditional of the set notify * flag, as _all_ clients that reside on the adapter * must be deleted, as this would cause invalid states. */ if ((res=client->driver->detach_client(client))) { dev_err(&adap->dev, "adapter not " "unregistered, because client at " "address %02x can't be detached. ", client->addr); goto out_unlock; } } /* clean up the sysfs representation */ init_completion(&adap->dev_released); init_completion(&adap->class_dev_released); class_device_unregister(&adap->class_dev); device_remove_file(&adap->dev, &dev_attr_name); device_unregister(&adap->dev); list_del(&adap->list); /* wait for sysfs to drop all references */ wait_for_completion(&adap->dev_released); wait_for_completion(&adap->class_dev_released); DEB(dev_dbg(&adap->dev, "adapter unregistered\n")); out_unlock: up(&core_lists); return res; } /* ----- * What follows is the "upwards" interface: commands for talking to clients, * which implement the functions to access the physical information of the * chips. */ int i2c_add_driver(struct i2c_driver *driver) { struct list_head *item; struct i2c_adapter *adapter; int res = 0; down(&core_lists); /* add the driver to the list of i2c drivers in the driver core */ driver->driver.name = driver->name; driver->driver.bus = &i2c_bus_type; driver->driver.probe = i2c_device_probe; driver->driver.remove = i2c_device_remove; res = driver_register(&driver->driver); if (res) goto out_unlock; list_add_tail(&driver->list,&drivers); DEB(printk(KERN_DEBUG "i2c-core.o: driver %s registered.\n",driver->name)); /* now look for instances of driver on our adapters */ if (driver->flags & I2C_DF_NOTIFY) { list_for_each(item,&adapters) { adapter = list_entry(item, struct i2c_adapter, list); driver->attach_adapter(adapter); } } out_unlock: up(&core_lists); return res; } int i2c_del_driver(struct i2c_driver *driver) { struct list_head *item1, *item2, *_n; struct i2c_client *client; struct i2c_adapter *adap; int res = 0; down(&core_lists); /* Have a look at each adapter, if clients of this driver are still * attached. If so, detach them to be able to kill the driver * afterwards. */ DEB2(printk(KERN_DEBUG "i2c-core.o: unregister_driver - looking for clients.\n")); /* removing clients does not depend on the notify flag, else * invalid operation might (will!) result, when using stale client * pointers. */ list_for_each(item1,&adapters) { adap = list_entry(item1, struct i2c_adapter, list); DEB2(dev_dbg(&adap->dev, "examining adapter\n")); if (driver->detach_adapter) { if ((res = driver->detach_adapter(adap))) { dev_warn(&adap->dev, "while unregistering " "dummy driver %s, adapter could " "not be detached properly; driver " "not unloaded!",driver->name); goto out_unlock; } } else { list_for_each_safe(item2, _n, &adap->clients) { client = list_entry(item2, struct i2c_client, list); if (client->driver != driver) continue; DEB2(printk(KERN_DEBUG "i2c-core.o: " "detaching client %s:\n", client->name)); if ((res = driver->detach_client(client))) { dev_err(&adap->dev, "while " "unregistering driver " "`%s', the client at " "address %02x of " "adapter could not " "be detached; driver " "not unloaded!", driver->name, client->addr); goto out_unlock; } } } } driver_unregister(&driver->driver); list_del(&driver->list); DEB(printk(KERN_DEBUG "i2c-core.o: driver unregistered: %s\n",driver->name)); out_unlock: up(&core_lists); return 0; } static int __i2c_check_addr(struct i2c_adapter *adapter, unsigned int addr) { struct list_head *item; struct i2c_client *client; list_for_each(item,&adapter->clients) { client = list_entry(item, struct i2c_client, list); if (client->addr == addr) return -EBUSY; } return 0; } int i2c_check_addr(struct i2c_adapter *adapter, int addr) { int rval; down(&adapter->clist_lock); rval = __i2c_check_addr(adapter, addr); up(&adapter->clist_lock); return rval; } int i2c_attach_client(struct i2c_client *client) { struct i2c_adapter *adapter = client->adapter; down(&adapter->clist_lock); if (__i2c_check_addr(client->adapter, client->addr)) { up(&adapter->clist_lock); return -EBUSY; } list_add_tail(&client->list,&adapter->clients); up(&adapter->clist_lock); if (adapter->client_register) { if (adapter->client_register(client)) { dev_warn(&adapter->dev, "warning: client_register " "seems to have failed for client %02x\n", client->addr); } } DEB(dev_dbg(&adapter->dev, "client [%s] registered to adapter\n", client->dev.name)); if (client->flags & I2C_CLIENT_ALLOW_USE) client->usage_count = 0; client->dev.parent = &client->adapter->dev; client->dev.driver = &client->driver->driver; client->dev.bus = &i2c_bus_type; client->dev.release = &i2c_client_release; snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id), "%d-%04x", i2c_adapter_id(adapter), client->addr); printk("registering %s\n", client->dev.bus_id); device_register(&client->dev); device_create_file(&client->dev, &dev_attr_client_name); return 0; } int i2c_detach_client(struct i2c_client *client) { struct i2c_adapter *adapter = client->adapter; int res = 0; if ((client->flags & I2C_CLIENT_ALLOW_USE) && (client->usage_count > 0)) return -EBUSY; if (adapter->client_unregister) { res = adapter->client_unregister(client); if (res) { printk(KERN_ERR "i2c-core.o: client_unregister [%s] failed, " "client not detached", client->name); goto out; } } down(&adapter->clist_lock); list_del(&client->list); init_completion(&client->released); device_remove_file(&client->dev, &dev_attr_client_name); device_unregister(&client->dev); up(&adapter->clist_lock); wait_for_completion(&client->released); out: return res; } static int i2c_inc_use_client(struct i2c_client *client) { if (!try_module_get(client->driver->owner)) return -ENODEV; if (!try_module_get(client->adapter->owner)) { module_put(client->driver->owner); return -ENODEV; } return 0; } static void i2c_dec_use_client(struct i2c_client *client) { module_put(client->driver->owner); module_put(client->adapter->owner); } int i2c_use_client(struct i2c_client *client) { if (!i2c_inc_use_client(client)) return -ENODEV; if (client->flags & I2C_CLIENT_ALLOW_USE) { if (client->flags & I2C_CLIENT_ALLOW_MULTIPLE_USE) client->usage_count++; else if (client->usage_count > 0) goto busy; else client->usage_count++; } return 0; busy: i2c_dec_use_client(client); return -EBUSY; } int i2c_release_client(struct i2c_client *client) { if(client->flags & I2C_CLIENT_ALLOW_USE) { if(client->usage_count>0) client->usage_count--; else { printk(KERN_WARNING " i2c-core.o: dec_use_client used one too many times\n"); return -EPERM; } } i2c_dec_use_client(client); return 0; } void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) { struct list_head *item; struct i2c_client *client; down(&adap->clist_lock); list_for_each(item,&adap->clients) { client = list_entry(item, struct i2c_client, list); if (!try_module_get(client->driver->owner)) continue; if (NULL != client->driver->command) { up(&adap->clist_lock); client->driver->command(client,cmd,arg); down(&adap->clist_lock); } module_put(client->driver->owner); } up(&adap->clist_lock); } /* match always succeeds, as we want the probe() to tell if we really accept this match */ static int i2c_device_match(struct device *dev, struct device_driver *drv) { return 1; } struct bus_type i2c_bus_type = { .name = "i2c", .match = i2c_device_match, }; static int __init i2c_init(void) { int retval; retval = bus_register(&i2c_bus_type); if (retval) return retval; retval = driver_register(&i2c_adapter_driver); if (retval) return retval; return class_register(&i2c_adapter_class); } static void __exit i2c_exit(void) { class_unregister(&i2c_adapter_class); driver_unregister(&i2c_adapter_driver); bus_unregister(&i2c_bus_type); } subsys_initcall(i2c_init); module_exit(i2c_exit); /* ---------------------------------------------------- * the functional interface to the i2c busses. * ---------------------------------------------------- */ int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg msgs[],int num) { int ret; if (adap->algo->master_xfer) { DEB2(dev_dbg(&adap->dev, "master_xfer: with %d msgs.\n", num)); down(&adap->bus_lock); ret = adap->algo->master_xfer(adap,msgs,num); up(&adap->bus_lock); return ret; } else { DEB2(dev_dbg(&adap->dev, "I2C level transfers not supported\n")); return -ENOSYS; } } int i2c_master_send(struct i2c_client *client,const char *buf ,int count) { int ret; struct i2c_adapter *adap=client->adapter; struct i2c_msg msg; if (client->adapter->algo->master_xfer) { msg.addr = client->addr; msg.flags = client->flags & I2C_M_TEN; msg.len = count; msg.buf = (char *)buf; DEB2(dev_dbg(&client->adapter->dev, "master_send: writing %d bytes.\n", count)); down(&adap->bus_lock); ret = adap->algo->master_xfer(adap,&msg,1); up(&adap->bus_lock); /* if everything went ok (i.e. 1 msg transmitted), return #bytes * transmitted, else error code. */ return (ret == 1 )? count : ret; } else { dev_err(&client->adapter->dev, "I2C level transfers not supported\n"); return -ENOSYS; } } int i2c_master_recv(struct i2c_client *client, char *buf ,int count) { struct i2c_adapter *adap=client->adapter; struct i2c_msg msg; int ret; if (client->adapter->algo->master_xfer) { msg.addr = client->addr; msg.flags = client->flags & I2C_M_TEN; msg.flags |= I2C_M_RD; msg.len = count; msg.buf = buf; DEB2(dev_dbg(&client->adapter->dev, "master_recv: reading %d bytes.\n", count)); down(&adap->bus_lock); ret = adap->algo->master_xfer(adap,&msg,1); up(&adap->bus_lock); DEB2(printk(KERN_DEBUG "i2c-core.o: master_recv: return:%d (count:%d, addr:0x%02x)\n", ret, count, client->addr)); /* if everything went ok (i.e. 1 msg transmitted), return #bytes * transmitted, else error code. */ return (ret == 1 )? count : ret; } else { dev_err(&client->adapter->dev, "I2C level transfers not supported\n"); return -ENOSYS; } } int i2c_control(struct i2c_client *client, unsigned int cmd, unsigned long arg) { int ret = 0; struct i2c_adapter *adap = client->adapter; DEB2(printk(KERN_DEBUG "i2c-core.o: i2c ioctl, cmd: 0x%x, arg: %#lx\n", cmd, arg)); switch ( cmd ) { case I2C_RETRIES: adap->retries = arg; break; case I2C_TIMEOUT: adap->timeout = arg; break; default: if (adap->algo->algo_control!=NULL) ret = adap->algo->algo_control(adap,cmd,arg); } return ret; } /* ---------------------------------------------------- * the i2c address scanning function * Will not work for 10-bit addresses! * ---------------------------------------------------- */ int i2c_probe(struct i2c_adapter *adapter, struct i2c_client_address_data *address_data, int (*found_proc) (struct i2c_adapter *, int, int)) { int addr,i,found,err; int adap_id = i2c_adapter_id(adapter); /* Forget it if we can't probe using SMBUS_QUICK */ if (! i2c_check_functionality(adapter,I2C_FUNC_SMBUS_QUICK)) return -1; for (addr = 0x00; addr <= 0x7f; addr++) { /* Skip if already in use */ if (i2c_check_addr(adapter,addr)) continue; /* If it is in one of the force entries, we don't do any detection at all */ found = 0; for (i = 0; !found && (address_data->force[i] != I2C_CLIENT_END); i += 3) { if (((adap_id == address_data->force[i]) || (address_data->force[i] == ANY_I2C_BUS)) && (addr == address_data->force[i+1])) { DEB2(printk(KERN_DEBUG "i2c-core.o: found force parameter for adapter %d, addr %04x\n", adap_id,addr)); if ((err = found_proc(adapter,addr,0))) return err; found = 1; } } if (found) continue; /* If this address is in one of the ignores, we can forget about it right now */ for (i = 0; !found && (address_data->ignore[i] != I2C_CLIENT_END); i += 2) { if (((adap_id == address_data->ignore[i]) || ((address_data->ignore[i] == ANY_I2C_BUS))) && (addr == address_data->ignore[i+1])) { DEB2(printk(KERN_DEBUG "i2c-core.o: found ignore parameter for adapter %d, " "addr %04x\n", adap_id ,addr)); found = 1; } } for (i = 0; !found && (address_data->ignore_range[i] != I2C_CLIENT_END); i += 3) { if (((adap_id == address_data->ignore_range[i]) || ((address_data->ignore_range[i]==ANY_I2C_BUS))) && (addr >= address_data->ignore_range[i+1]) && (addr <= address_data->ignore_range[i+2])) { DEB2(printk(KERN_DEBUG "i2c-core.o: found ignore_range parameter for adapter %d, " "addr %04x\n", adap_id,addr)); found = 1; } } if (found) continue; /* Now, we will do a detection, but only if it is in the normal or probe entries */ for (i = 0; !found && (address_data->normal_i2c[i] != I2C_CLIENT_END); i += 1) { if (addr == address_data->normal_i2c[i]) { found = 1; DEB2(printk(KERN_DEBUG "i2c-core.o: found normal i2c entry for adapter %d, " "addr %02x", adap_id,addr)); } } for (i = 0; !found && (address_data->normal_i2c_range[i] != I2C_CLIENT_END); i += 2) { if ((addr >= address_data->normal_i2c_range[i]) && (addr <= address_data->normal_i2c_range[i+1])) { found = 1; DEB2(printk(KERN_DEBUG "i2c-core.o: found normal i2c_range entry for adapter %d, " "addr %04x\n", adap_id,addr)); } } for (i = 0; !found && (address_data->probe[i] != I2C_CLIENT_END); i += 2) { if (((adap_id == address_data->probe[i]) || ((address_data->probe[i] == ANY_I2C_BUS))) && (addr == address_data->probe[i+1])) { found = 1; DEB2(printk(KERN_DEBUG "i2c-core.o: found probe parameter for adapter %d, " "addr %04x\n", adap_id,addr)); } } for (i = 0; !found && (address_data->probe_range[i] != I2C_CLIENT_END); i += 3) { if (((adap_id == address_data->probe_range[i]) || (address_data->probe_range[i] == ANY_I2C_BUS)) && (addr >= address_data->probe_range[i+1]) && (addr <= address_data->probe_range[i+2])) { found = 1; DEB2(printk(KERN_DEBUG "i2c-core.o: found probe_range parameter for adapter %d, " "addr %04x\n", adap_id,addr)); } } if (!found) continue; /* OK, so we really should examine this address. First check whether there is some client here at all! */ if (i2c_smbus_xfer(adapter,addr,0,0,0,I2C_SMBUS_QUICK,NULL) >= 0) if ((err = found_proc(adapter,addr,-1))) return err; } return 0; } /* * return id number for a specific adapter */ int i2c_adapter_id(struct i2c_adapter *adap) { return adap->nr; } struct i2c_adapter* i2c_get_adapter(int id) { struct list_head *item; struct i2c_adapter *adapter; down(&core_lists); list_for_each(item,&adapters) { adapter = list_entry(item, struct i2c_adapter, list); if (id == adapter->nr && try_module_get(adapter->owner)) { up(&core_lists); return adapter; } } up(&core_lists); return NULL; } void i2c_put_adapter(struct i2c_adapter *adap) { module_put(adap->owner); } /* The SMBus parts */ #define POLY (0x1070U << 3) static u8 crc8(u16 data) { int i; for(i = 0; i < 8; i++) { if (data & 0x8000) data = data ^ POLY; data = data << 1; } return (u8)(data >> 8); } /* CRC over count bytes in the first array plus the bytes in the rest array if it is non-null. rest[0] is the (length of rest) - 1 and is included. */ u8 i2c_smbus_partial_pec(u8 crc, int count, u8 *first, u8 *rest) { int i; for(i = 0; i < count; i++) crc = crc8((crc ^ first[i]) << 8); if(rest != NULL) for(i = 0; i <= rest[0]; i++) crc = crc8((crc ^ rest[i]) << 8); return crc; } u8 i2c_smbus_pec(int count, u8 *first, u8 *rest) { return i2c_smbus_partial_pec(0, count, first, rest); } /* Returns new "size" (transaction type) Note that we convert byte to byte_data and byte_data to word_data rather than invent new xxx_PEC transactions. */ int i2c_smbus_add_pec(u16 addr, u8 command, int size, union i2c_smbus_data *data) { u8 buf[3]; buf[0] = addr << 1; buf[1] = command; switch(size) { case I2C_SMBUS_BYTE: data->byte = i2c_smbus_pec(2, buf, NULL); size = I2C_SMBUS_BYTE_DATA; break; case I2C_SMBUS_BYTE_DATA: buf[2] = data->byte; data->word = buf[2] || (i2c_smbus_pec(3, buf, NULL) << 8); size = I2C_SMBUS_WORD_DATA; break; case I2C_SMBUS_WORD_DATA: /* unsupported */ break; case I2C_SMBUS_BLOCK_DATA: data->block[data->block[0] + 1] = i2c_smbus_pec(2, buf, data->block); size = I2C_SMBUS_BLOCK_DATA_PEC; break; } return size; } int i2c_smbus_check_pec(u16 addr, u8 command, int size, u8 partial, union i2c_smbus_data *data) { u8 buf[3], rpec, cpec; buf[1] = command; switch(size) { case I2C_SMBUS_BYTE_DATA: buf[0] = (addr << 1) | 1; cpec = i2c_smbus_pec(2, buf, NULL); rpec = data->byte; break; case I2C_SMBUS_WORD_DATA: buf[0] = (addr << 1) | 1; buf[2] = data->word & 0xff; cpec = i2c_smbus_pec(3, buf, NULL); rpec = data->word >> 8; break; case I2C_SMBUS_WORD_DATA_PEC: /* unsupported */ cpec = rpec = 0; break; case I2C_SMBUS_PROC_CALL_PEC: /* unsupported */ cpec = rpec = 0; break; case I2C_SMBUS_BLOCK_DATA_PEC: buf[0] = (addr << 1); buf[2] = (addr << 1) | 1; cpec = i2c_smbus_pec(3, buf, data->block); rpec = data->block[data->block[0] + 1]; break; case I2C_SMBUS_BLOCK_PROC_CALL_PEC: buf[0] = (addr << 1) | 1; rpec = i2c_smbus_partial_pec(partial, 1, buf, data->block); cpec = data->block[data->block[0] + 1]; break; default: cpec = rpec = 0; break; } if(rpec != cpec) { DEB(printk(KERN_DEBUG "i2c-core.o: Bad PEC 0x%02x vs. 0x%02x\n", rpec, cpec)); return -1; } return 0; } s32 i2c_smbus_write_quick(struct i2c_client *client, u8 value) { return i2c_smbus_xfer(client->adapter,client->addr,client->flags, value,0,I2C_SMBUS_QUICK,NULL); } s32 i2c_smbus_read_byte(struct i2c_client *client) { union i2c_smbus_data data; if (i2c_smbus_xfer(client->adapter,client->addr,client->flags, I2C_SMBUS_READ,0,I2C_SMBUS_BYTE, &data)) return -1; else return 0x0FF & data.byte; } s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value) { union i2c_smbus_data data; /* only for PEC */ return i2c_smbus_xfer(client->adapter,client->addr,client->flags, I2C_SMBUS_WRITE,value, I2C_SMBUS_BYTE,&data); } s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command) { union i2c_smbus_data data; if (i2c_smbus_xfer(client->adapter,client->addr,client->flags, I2C_SMBUS_READ,command, I2C_SMBUS_BYTE_DATA,&data)) return -1; else return 0x0FF & data.byte; } s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value) { union i2c_smbus_data data; data.byte = value; return i2c_smbus_xfer(client->adapter,client->addr,client->flags, I2C_SMBUS_WRITE,command, I2C_SMBUS_BYTE_DATA,&data); } s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command) { union i2c_smbus_data data; if (i2c_smbus_xfer(client->adapter,client->addr,client->flags, I2C_SMBUS_READ,command, I2C_SMBUS_WORD_DATA, &data)) return -1; else return 0x0FFFF & data.word; } s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value) { union i2c_smbus_data data; data.word = value; return i2c_smbus_xfer(client->adapter,client->addr,client->flags, I2C_SMBUS_WRITE,command, I2C_SMBUS_WORD_DATA,&data); } s32 i2c_smbus_process_call(struct i2c_client *client, u8 command, u16 value) { union i2c_smbus_data data; data.word = value; if (i2c_smbus_xfer(client->adapter,client->addr,client->flags, I2C_SMBUS_WRITE,command, I2C_SMBUS_PROC_CALL, &data)) return -1; else return 0x0FFFF & data.word; } /* Returns the number of read bytes */ s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command, u8 *values) { union i2c_smbus_data data; int i; if (i2c_smbus_xfer(client->adapter,client->addr,client->flags, I2C_SMBUS_READ,command, I2C_SMBUS_BLOCK_DATA,&data)) return -1; else { for (i = 1; i <= data.block[0]; i++) values[i-1] = data.block[i]; return data.block[0]; } } s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, u8 length, u8 *values) { union i2c_smbus_data data; int i; if (length > I2C_SMBUS_BLOCK_MAX) length = I2C_SMBUS_BLOCK_MAX; for (i = 1; i <= length; i++) data.block[i] = values[i-1]; data.block[0] = length; return i2c_smbus_xfer(client->adapter,client->addr,client->flags, I2C_SMBUS_WRITE,command, I2C_SMBUS_BLOCK_DATA,&data); } /* Returns the number of read bytes */ s32 i2c_smbus_block_process_call(struct i2c_client *client, u8 command, u8 length, u8 *values) { union i2c_smbus_data data; int i; if (length > I2C_SMBUS_BLOCK_MAX - 1) return -1; data.block[0] = length; for (i = 1; i <= length; i++) data.block[i] = values[i-1]; if(i2c_smbus_xfer(client->adapter,client->addr,client->flags, I2C_SMBUS_WRITE, command, I2C_SMBUS_BLOCK_PROC_CALL, &data)) return -1; for (i = 1; i <= data.block[0]; i++) values[i-1] = data.block[i]; return data.block[0]; } /* Returns the number of read bytes */ s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, u8 *values) { union i2c_smbus_data data; int i; if (i2c_smbus_xfer(client->adapter,client->addr,client->flags, I2C_SMBUS_READ,command, I2C_SMBUS_I2C_BLOCK_DATA,&data)) return -1; else { for (i = 1; i <= data.block[0]; i++) values[i-1] = data.block[i]; return data.block[0]; } } s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command, u8 length, u8 *values) { union i2c_smbus_data data; int i; if (length > I2C_SMBUS_I2C_BLOCK_MAX) length = I2C_SMBUS_I2C_BLOCK_MAX; for (i = 1; i <= length; i++) data.block[i] = values[i-1]; data.block[0] = length; return i2c_smbus_xfer(client->adapter,client->addr,client->flags, I2C_SMBUS_WRITE,command, I2C_SMBUS_I2C_BLOCK_DATA,&data); } /* Simulate a SMBus command using the i2c protocol No checking of parameters is done! */ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, unsigned short flags, char read_write, u8 command, int size, union i2c_smbus_data * data) { /* So we need to generate a series of msgs. In the case of writing, we need to use only one message; when reading, we need two. We initialize most things with sane defaults, to keep the code below somewhat simpler. */ unsigned char msgbuf0[34]; unsigned char msgbuf1[34]; int num = read_write == I2C_SMBUS_READ?2:1; struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 }, { addr, flags | I2C_M_RD, 0, msgbuf1 } }; int i; msgbuf0[0] = command; switch(size) { case I2C_SMBUS_QUICK: msg[0].len = 0; /* Special case: The read/write field is used as data */ msg[0].flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0; num = 1; break; case I2C_SMBUS_BYTE: if (read_write == I2C_SMBUS_READ) { /* Special case: only a read! */ msg[0].flags = I2C_M_RD | flags; num = 1; } break; case I2C_SMBUS_BYTE_DATA: if (read_write == I2C_SMBUS_READ) msg[1].len = 1; else { msg[0].len = 2; msgbuf0[1] = data->byte; } break; case I2C_SMBUS_WORD_DATA: if (read_write == I2C_SMBUS_READ) msg[1].len = 2; else { msg[0].len=3; msgbuf0[1] = data->word & 0xff; msgbuf0[2] = (data->word >> 8) & 0xff; } break; case I2C_SMBUS_PROC_CALL: num = 2; /* Special case */ read_write = I2C_SMBUS_READ; msg[0].len = 3; msg[1].len = 2; msgbuf0[1] = data->word & 0xff; msgbuf0[2] = (data->word >> 8) & 0xff; break; case I2C_SMBUS_BLOCK_DATA: case I2C_SMBUS_BLOCK_DATA_PEC: if (read_write == I2C_SMBUS_READ) { printk(KERN_ERR "i2c-core.o: Block read not supported " "under I2C emulation!\n"); return -1; } else { msg[0].len = data->block[0] + 2; if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { printk(KERN_ERR "i2c-core.o: smbus_access called with " "invalid block write size (%d)\n", data->block[0]); return -1; } if(size == I2C_SMBUS_BLOCK_DATA_PEC) (msg[0].len)++; for (i = 1; i <= msg[0].len; i++) msgbuf0[i] = data->block[i-1]; } break; case I2C_SMBUS_BLOCK_PROC_CALL: case I2C_SMBUS_BLOCK_PROC_CALL_PEC: printk(KERN_ERR "i2c-core.o: Block process call not supported " "under I2C emulation!\n"); return -1; case I2C_SMBUS_I2C_BLOCK_DATA: if (read_write == I2C_SMBUS_READ) { msg[1].len = I2C_SMBUS_I2C_BLOCK_MAX; } else { msg[0].len = data->block[0] + 1; if (msg[0].len > I2C_SMBUS_I2C_BLOCK_MAX + 1) { printk("i2c-core.o: i2c_smbus_xfer_emulated called with " "invalid block write size (%d)\n", data->block[0]); return -1; } for (i = 1; i <= data->block[0]; i++) msgbuf0[i] = data->block[i]; } break; default: printk(KERN_ERR "i2c-core.o: smbus_access called with invalid size (%d)\n", size); return -1; } if (i2c_transfer(adapter, msg, num) < 0) return -1; if (read_write == I2C_SMBUS_READ) switch(size) { case I2C_SMBUS_BYTE: data->byte = msgbuf0[0]; break; case I2C_SMBUS_BYTE_DATA: data->byte = msgbuf1[0]; break; case I2C_SMBUS_WORD_DATA: case I2C_SMBUS_PROC_CALL: data->word = msgbuf1[0] | (msgbuf1[1] << 8); break; case I2C_SMBUS_I2C_BLOCK_DATA: /* fixed at 32 for now */ data->block[0] = I2C_SMBUS_I2C_BLOCK_MAX; for (i = 0; i < I2C_SMBUS_I2C_BLOCK_MAX; i++) data->block[i+1] = msgbuf1[i]; break; } return 0; } s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags, char read_write, u8 command, int size, union i2c_smbus_data * data) { s32 res; int swpec = 0; u8 partial = 0; flags &= I2C_M_TEN | I2C_CLIENT_PEC; if((flags & I2C_CLIENT_PEC) && !(i2c_check_functionality(adapter, I2C_FUNC_SMBUS_HWPEC_CALC))) { swpec = 1; if(read_write == I2C_SMBUS_READ && size == I2C_SMBUS_BLOCK_DATA) size = I2C_SMBUS_BLOCK_DATA_PEC; else if(size == I2C_SMBUS_PROC_CALL) size = I2C_SMBUS_PROC_CALL_PEC; else if(size == I2C_SMBUS_BLOCK_PROC_CALL) { i2c_smbus_add_pec(addr, command, I2C_SMBUS_BLOCK_DATA, data); partial = data->block[data->block[0] + 1]; size = I2C_SMBUS_BLOCK_PROC_CALL_PEC; } else if(read_write == I2C_SMBUS_WRITE && size != I2C_SMBUS_QUICK && size != I2C_SMBUS_I2C_BLOCK_DATA) size = i2c_smbus_add_pec(addr, command, size, data); } if (adapter->algo->smbus_xfer) { down(&adapter->bus_lock); res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write, command,size,data); up(&adapter->bus_lock); } else res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write, command,size,data); if(res >= 0 && swpec && size != I2C_SMBUS_QUICK && size != I2C_SMBUS_I2C_BLOCK_DATA && (read_write == I2C_SMBUS_READ || size == I2C_SMBUS_PROC_CALL_PEC || size == I2C_SMBUS_BLOCK_PROC_CALL_PEC)) { if(i2c_smbus_check_pec(addr, command, size, partial, data)) return -1; } return res; } /* You should always define `functionality'; the 'else' is just for backward compatibility. */ u32 i2c_get_functionality (struct i2c_adapter *adap) { if (adap->algo->functionality) return adap->algo->functionality(adap); else return 0xffffffff; } int i2c_check_functionality (struct i2c_adapter *adap, u32 func) { u32 adap_func = i2c_get_functionality (adap); return (func & adap_func) == func; } EXPORT_SYMBOL(i2c_add_adapter); EXPORT_SYMBOL(i2c_del_adapter); EXPORT_SYMBOL(i2c_add_driver); EXPORT_SYMBOL(i2c_del_driver); EXPORT_SYMBOL(i2c_attach_client); EXPORT_SYMBOL(i2c_detach_client); EXPORT_SYMBOL(i2c_use_client); EXPORT_SYMBOL(i2c_release_client); EXPORT_SYMBOL(i2c_clients_command); EXPORT_SYMBOL(i2c_check_addr); EXPORT_SYMBOL(i2c_master_send); EXPORT_SYMBOL(i2c_master_recv); EXPORT_SYMBOL(i2c_control); EXPORT_SYMBOL(i2c_transfer); EXPORT_SYMBOL(i2c_adapter_id); EXPORT_SYMBOL(i2c_get_adapter); EXPORT_SYMBOL(i2c_put_adapter); EXPORT_SYMBOL(i2c_probe); EXPORT_SYMBOL(i2c_smbus_xfer); EXPORT_SYMBOL(i2c_smbus_write_quick); EXPORT_SYMBOL(i2c_smbus_read_byte); EXPORT_SYMBOL(i2c_smbus_write_byte); EXPORT_SYMBOL(i2c_smbus_read_byte_data); EXPORT_SYMBOL(i2c_smbus_write_byte_data); EXPORT_SYMBOL(i2c_smbus_read_word_data); EXPORT_SYMBOL(i2c_smbus_write_word_data); EXPORT_SYMBOL(i2c_smbus_process_call); EXPORT_SYMBOL(i2c_smbus_read_block_data); EXPORT_SYMBOL(i2c_smbus_write_block_data); EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); EXPORT_SYMBOL(i2c_get_functionality); EXPORT_SYMBOL(i2c_check_functionality); MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); MODULE_DESCRIPTION("I2C-Bus main module"); MODULE_LICENSE("GPL"); MODULE_PARM(i2c_debug, "i"); MODULE_PARM_DESC(i2c_debug,"debug level"); |