Commit 6dbda5bf authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging 

Pull hwmon fix from Guenter Roeck:
 "Improve chip detection in ADM1021 driver to avoid misdetections

  This is not a critical patch, but one we'll want to have applied to
  -stable, since the misdetection especially of LM84 has been causing
  trouble for quite some time."

* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (adm1021) Strengthen chip detection for ADM1021, LM84 and MAX1617
parents 317ddd25 591bfcfc

drivers/hwmon/adm1021.c

+50 −8
Original line number Diff line number Diff line
@@ -331,26 +331,68 @@ static int adm1021_detect(struct i2c_client *client, 
	man_id = i2c_smbus_read_byte_data(client, ADM1021_REG_MAN_ID);

	dev_id = i2c_smbus_read_byte_data(client, ADM1021_REG_DEV_ID);



	if (man_id < 0 || dev_id < 0)

		return -ENODEV;



	if (man_id == 0x4d && dev_id == 0x01)

		type_name = "max1617a";

	else if (man_id == 0x41) {

		if ((dev_id & 0xF0) == 0x30)

			type_name = "adm1023";

		else

		else if ((dev_id & 0xF0) == 0x00)

			type_name = "adm1021";

		else

			return -ENODEV;

	} else if (man_id == 0x49)

		type_name = "thmc10";

	else if (man_id == 0x23)

		type_name = "gl523sm";

	else if (man_id == 0x54)

		type_name = "mc1066";

	/* LM84 Mfr ID in a different place, and it has more unused bits */

	else if (conv_rate == 0x00

	else {

		int lte, rte, lhi, rhi, llo, rlo;



		/* extra checks for LM84 and MAX1617 to avoid misdetections */



		llo = i2c_smbus_read_byte_data(client, ADM1021_REG_THYST_R(0));

		rlo = i2c_smbus_read_byte_data(client, ADM1021_REG_THYST_R(1));



		/* fail if any of the additional register reads failed */

		if (llo < 0 || rlo < 0)

			return -ENODEV;



		lte = i2c_smbus_read_byte_data(client, ADM1021_REG_TEMP(0));

		rte = i2c_smbus_read_byte_data(client, ADM1021_REG_TEMP(1));

		lhi = i2c_smbus_read_byte_data(client, ADM1021_REG_TOS_R(0));

		rhi = i2c_smbus_read_byte_data(client, ADM1021_REG_TOS_R(1));



		/*

		 * Fail for negative temperatures and negative high limits.

		 * This check also catches read errors on the tested registers.

		 */

		if ((s8)lte < 0 || (s8)rte < 0 || (s8)lhi < 0 || (s8)rhi < 0)

			return -ENODEV;



		/* fail if all registers hold the same value */

		if (lte == rte && lte == lhi && lte == rhi && lte == llo

		    && lte == rlo)

			return -ENODEV;



		/*

		 * LM84 Mfr ID is in a different place,

		 * and it has more unused bits.

		 */

		if (conv_rate == 0x00

		    && (config & 0x7F) == 0x00

		 && (status & 0xAB) == 0x00)

		    && (status & 0xAB) == 0x00) {

			type_name = "lm84";

	else

		} else {

			/* fail if low limits are larger than high limits */

			if ((s8)llo > lhi || (s8)rlo > rhi)

				return -ENODEV;

			type_name = "max1617";

		}

	}



	pr_debug("Detected chip %s at adapter %d, address 0x%02x.\n",

		 type_name, i2c_adapter_id(adapter), client->addr);

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