The existing driver for the LM75 is unable to identify a compatible DS75 device properly. This patch from http://lists.lm-sensors.org/pipermail/lm-sensors/2007-February/018838.html does fix the problem and I wonder why it did not make it into the kernel yet. Signed-off-by: Alan? Acked-by: Wolfgang Grandegger <wg at grandegger.com> --- drivers/hwmon/lm75.c | 59 +++++++++++++++++++++++++++++++-------------------- 1 file changed, 37 insertions(+), 22 deletions(-) Index: linux-2.6-denx/drivers/hwmon/lm75.c =================================================================== --- linux-2.6-denx.orig/drivers/hwmon/lm75.c +++ linux-2.6-denx/drivers/hwmon/lm75.c @@ -35,7 +35,7 @@ static const unsigned short normal_i2c[] 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; /* Insmod parameters */ -I2C_CLIENT_INSMOD_1(lm75); +I2C_CLIENT_INSMOD_2(lm75, ds75); /* Many LM75 constants specified below */ @@ -157,49 +157,64 @@ static int lm75_detect(struct i2c_adapte new_client->flags = 0; /* Now, we do the remaining detection. There is no identification- - dedicated register so we have to rely on several tricks: - unused bits, registers cycling over 8-address boundaries, - addresses 0x04-0x07 returning the last read value. + dedicated register so we have to rely on several tricks. + The LM75 and DS75 share unused bits. The LM75 has registers + cycling over 8-address boundaries, and addresses 0x04-0x07 + returning the last read value. + The DS75 has addresses 0x04-0x0f returning the last read value, + but does not register cycle. The cycling+unused addresses combination is not tested, since it would significantly slow the detection down and would hardly add any value. */ if (kind < 0) { - int cur, conf, hyst, os; + int cur, conf, hyst, os, addr; /* Unused addresses */ cur = i2c_smbus_read_word_data(new_client, 0); conf = i2c_smbus_read_byte_data(new_client, 1); hyst = i2c_smbus_read_word_data(new_client, 2); - if (i2c_smbus_read_word_data(new_client, 4) != hyst - || i2c_smbus_read_word_data(new_client, 5) != hyst - || i2c_smbus_read_word_data(new_client, 6) != hyst - || i2c_smbus_read_word_data(new_client, 7) != hyst) - goto exit_free; + + for (addr = 0x04; addr <= 0x0f; addr++) + if (i2c_smbus_read_word_data(new_client, addr) != hyst) + break; + + if (addr < 0x08) + goto exit_free; + if (addr == 0x10) + kind = ds75; + else + kind = lm75; + os = i2c_smbus_read_word_data(new_client, 3); - if (i2c_smbus_read_word_data(new_client, 4) != os - || i2c_smbus_read_word_data(new_client, 5) != os - || i2c_smbus_read_word_data(new_client, 6) != os - || i2c_smbus_read_word_data(new_client, 7) != os) - goto exit_free; + for (addr = 0x04; addr <= 0x0f; addr++) + if (i2c_smbus_read_word_data(new_client, addr) != os) + break; + + if (addr < (kind == ds75 ? 0x10 : 0x08)) + goto exit_free; /* Unused bits */ if (conf & 0xe0) goto exit_free; - /* Addresses cycling */ - for (i = 8; i < 0xff; i += 8) - if (i2c_smbus_read_byte_data(new_client, i + 1) != conf - || i2c_smbus_read_word_data(new_client, i + 2) != hyst - || i2c_smbus_read_word_data(new_client, i + 3) != os) - goto exit_free; + /* Addresses cycling - LM75 only */ + if (kind == lm75) { + for (i = 8; i < 0xff; i += 8) + if (i2c_smbus_read_byte_data(new_client, i + 1) != conf + || i2c_smbus_read_word_data(new_client, i + 2) != hyst + || i2c_smbus_read_word_data(new_client, i + 3) != os) + goto exit_free; + } } - /* Determine the chip type - only one kind supported! */ if (kind <= 0) kind = lm75; + /* Determine the chip type */ if (kind == lm75) { name = "lm75"; + } else if (kind == ds75) { + name = "ds75"; } /* Fill in the remaining client fields and put it into the global list */
