diff --git a/Documentation/i2c/writing-clients b/Documentation/i2c/writing-clients index 97e138cbb2a9..077275722a7c 100644 --- a/Documentation/i2c/writing-clients +++ b/Documentation/i2c/writing-clients @@ -241,9 +241,10 @@ Below, some things are only needed if this is a `sensors' driver. Those parts are between /* SENSORS ONLY START */ and /* SENSORS ONLY END */ markers. -This function should only return an error (any value != 0) if there is -some reason why no more detection should be done anymore. If the -detection just fails for this address, return 0. +Returning an error different from -ENODEV in a detect function will cause +the detection to stop: other addresses and adapters won't be scanned. +This should only be done on fatal or internal errors, such as a memory +shortage or i2c_attach_client failing. For now, you can ignore the `flags' parameter. It is there for future use. diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 372b5996d045..bee0148dfab8 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -662,107 +662,120 @@ int i2c_control(struct i2c_client *client, * Will not work for 10-bit addresses! * ---------------------------------------------------- */ -/* Return: kind (>= 0) if force found, -1 if not found */ -static inline int i2c_probe_forces(struct i2c_adapter *adapter, int addr, - unsigned short **forces) +static int i2c_probe_address(struct i2c_adapter *adapter, int addr, int kind, + int (*found_proc) (struct i2c_adapter *, int, int)) { - unsigned short kind; - int j, adap_id = i2c_adapter_id(adapter); + int err; - for (kind = 0; forces[kind]; kind++) { - for (j = 0; forces[kind][j] != I2C_CLIENT_END; j += 2) { - if ((forces[kind][j] == adap_id || - forces[kind][j] == ANY_I2C_BUS) - && forces[kind][j + 1] == addr) { - dev_dbg(&adapter->dev, "found force parameter, " - "addr 0x%02x, kind %u\n", addr, kind); - return kind; - } - } + /* Make sure the address is valid */ + if (addr < 0x03 || addr > 0x77) { + dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", + addr); + return -EINVAL; } - return -1; + /* Skip if already in use */ + if (i2c_check_addr(adapter, addr)) + return 0; + + /* Make sure there is something at this address, unless forced */ + if (kind < 0 + && i2c_smbus_xfer(adapter, addr, 0, 0, 0, I2C_SMBUS_QUICK, NULL) < 0) + return 0; + + /* Finally call the custom detection function */ + err = found_proc(adapter, addr, kind); + + /* -ENODEV can be returned if there is a chip at the given address + but it isn't supported by this chip driver. We catch it here as + this isn't an error. */ + return (err == -ENODEV) ? 0 : err; } 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 i, 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++) { + /* Force entries are done first, and are not affected by ignore + entries */ + if (address_data->forces) { + unsigned short **forces = address_data->forces; + int kind; - /* 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; - - if (address_data->forces) { - int kind = i2c_probe_forces(adapter, addr, - address_data->forces); - if (kind >= 0) { /* force found */ - if ((err = found_proc(adapter, addr, kind))) - return err; - continue; + for (kind = 0; forces[kind]; kind++) { + for (i = 0; forces[kind][i] != I2C_CLIENT_END; + i += 2) { + if (forces[kind][i] == adap_id + || forces[kind][i] == ANY_I2C_BUS) { + dev_dbg(&adapter->dev, "found force " + "parameter for adapter %d, " + "addr 0x%02x, kind %d\n", + adap_id, forces[kind][i + 1], + kind); + err = i2c_probe_address(adapter, + forces[kind][i + 1], + kind, found_proc); + if (err) + return err; + } } } - - /* 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])) { - dev_dbg(&adapter->dev, "found ignore 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; - dev_dbg(&adapter->dev, "found normal i2c entry for adapter %d, " - "addr %02x\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; - dev_dbg(&adapter->dev, "found probe 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; } + + /* Probe entries are done second, and are not affected by ignore + entries either */ + for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) { + if (address_data->probe[i] == adap_id + || address_data->probe[i] == ANY_I2C_BUS) { + dev_dbg(&adapter->dev, "found probe parameter for " + "adapter %d, addr 0x%02x\n", adap_id, + address_data->probe[i + 1]); + err = i2c_probe_address(adapter, + address_data->probe[i + 1], + -1, found_proc); + if (err) + return err; + } + } + + /* Normal entries are done last, unless shadowed by an ignore entry */ + for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) { + int j, ignore; + + ignore = 0; + for (j = 0; address_data->ignore[j] != I2C_CLIENT_END; + j += 2) { + if ((address_data->ignore[j] == adap_id || + address_data->ignore[j] == ANY_I2C_BUS) + && address_data->ignore[j + 1] + == address_data->normal_i2c[i]) { + dev_dbg(&adapter->dev, "found ignore " + "parameter for adapter %d, " + "addr 0x%02x\n", adap_id, + address_data->ignore[j + 1]); + } + ignore = 1; + break; + } + if (ignore) + continue; + + dev_dbg(&adapter->dev, "found normal entry for adapter %d, " + "addr 0x%02x\n", adap_id, + address_data->normal_i2c[i]); + err = i2c_probe_address(adapter, address_data->normal_i2c[i], + -1, found_proc); + if (err) + return err; + } + return 0; }