Исследование драйвера ядра Linux для шины I2C

  597                 "len=%d\n", ret, msgs[ret].flags & I2C_M_RD ?

  598                 'R' : 'W', msgs[ret].addr, msgs[ret].len);

  599         }

  600 #endif

  601

  602         down(&adap->bus_lock);

  603         ret = adap->algo->master_xfer(adap,msgs,num);

  604         up(&adap->bus_lock);

  605

  606         return ret;

  607     } else {

  608         dev_dbg(&adap->dev, "I2C level transfers not supported\n");

  609         return -ENOSYS;

  610     }

  611 }

  612

  613 int i2c_master_send(struct i2c_client *client,const char *buf ,int count)

  614 {

  615     int ret;

  616     struct i2c_adapter *adap=client->adapter;

  617     struct i2c_msg msg;

  618

  619     msg.addr = client->addr;

  620     msg.flags = client->flags & I2C_M_TEN;

  621     msg.len = count;

  622     msg.buf = (char *)buf;

  623

  624     ret = i2c_transfer(adap, &msg, 1);

  625

  626     /* If everything went ok (i.e. 1 msg transmitted), return #bytes

  627        transmitted, else error code. */

  628     return (ret == 1) ? count : ret;

  629 }

  630

  631 int i2c_master_recv(struct i2c_client *client, char *buf ,int count)

  632 {

  633     struct i2c_adapter *adap=client->adapter;

  634     struct i2c_msg msg;

  635     int ret;

  636

  637     msg.addr = client->addr;

  638     msg.flags = client->flags & I2C_M_TEN;

  639     msg.flags |= I2C_M_RD;

  640     msg.len = count;

  641     msg.buf = buf;

  642

  643     ret = i2c_transfer(adap, &msg, 1);

  644

  645     /* If everything went ok (i.e. 1 msg transmitted), return #bytes

  646        transmitted, else error code. */

  647     return (ret == 1) ? count : ret;

  648 }

  649

  650

  651 int i2c_control(struct i2c_client *client,

  652     unsigned int cmd, unsigned long arg)

  653 {

  654     int ret = 0;

  655     struct i2c_adapter *adap = client->adapter;

  656

  657     dev_dbg(&client->adapter->dev, "i2c ioctl, cmd: 0x%x, arg: %#lx\n", cmd,

  658             arg);

  659     switch (cmd) {

  660         case I2C_RETRIES:

  661             adap->retries = arg;

  662             break;

  663         case I2C_TIMEOUT:

  664             adap->timeout = arg;

  665             break;

  666         default:

  667             if (adap->algo->algo_control!=NULL)

  668                 ret = adap->algo->algo_control(adap,cmd,arg);

  669     }

  670     return ret;

  671 }

  672

  673 /* ----------------------------------------------------

  674 * the i2c address scanning function

  675 * Will not work for 10-bit addresses!

  676 * ----------------------------------------------------

  677 */

  678 static int i2c_probe_address(struct i2c_adapter *adapter, int addr, int

  679                              kind,

  680                  int (*found_proc) (struct i2c_adapter *, int, int))

  681 {

  682     int err;

  683

  684     /* Make sure the address is valid */

  685     if (addr < 0x03 || addr > 0x77) {

  686         dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",

  687              addr);

  688         return -EINVAL;

  689     }

  690

  691     /* Skip if already in use */

  692     if (i2c_check_addr(adapter, addr))

  693         return 0;

  694

  695     /* Make sure there is something at this address, unless forced */

  696     if (kind < 0) {

  697         if (i2c_smbus_xfer(adapter, addr, 0, 0, 0,

  698                   I2C_SMBUS_QUICK, NULL) < 0)

  699             return 0;

  700

  701         /* prevent 24RF08 corruption */

  702         if ((addr & ~0x0f) == 0x50)

  703             i2c_smbus_xfer(adapter, addr, 0, 0, 0,

  704                        I2C_SMBUS_QUICK, NULL);

  705     }

  706

  707     /* Finally call the custom detection function */

  708     err = found_proc(adapter, addr, kind);

  709

  710     /* -ENODEV can be returned if there is a chip at the given address

  711        but it isn't supported by this chip driver. We catch it here as

  712        this isn't an error. */

  713     return (err == -ENODEV) ? 0 : err;

  714 }

  715

  716 int i2c_probe(struct i2c_adapter *adapter,

  717           struct i2c_client_address_data *address_data,

  718           int (*found_proc) (struct i2c_adapter *, int, int))

  719 {

  720     int i, err;

  721     int adap_id = i2c_adapter_id(adapter);

  722

  723     /* Force entries are done first, and are not affected by ignore

  724        entries */

  725     if (address_data->forces) {

  726         unsigned short **forces = address_data->forces;

  727         int kind;

  728

  729         for (kind = 0; forces[kind]; kind++) {

  730             for (i = 0; forces[kind][i] != I2C_CLIENT_END;

  731                  i += 2) {

  732                 if (forces[kind][i] == adap_id

  733                  || forces[kind][i] == ANY_I2C_BUS) {

  734                     dev_dbg(&adapter->dev, "found force "

  735                         "parameter for adapter %d, "

  736                         "addr 0x%02x, kind %d\n",

  737                         adap_id, forces[kind][i + 1],

  738                         kind);

  739                     err = i2c_probe_address(adapter,

  740                         forces[kind][i + 1],

  741                         kind, found_proc);

  742                     if (err)

  743                         return err;

  744                 }

  745             }

  746         }

  747     }

  748

  749     /* Stop here if we can't use SMBUS_QUICK */