From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756117Ab3FPWQh (ORCPT ); Sun, 16 Jun 2013 18:16:37 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:46416 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755709Ab3FPWJG (ORCPT ); Sun, 16 Jun 2013 18:09:06 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Guenter Roeck" , "Jean Delvare" Date: Sun, 16 Jun 2013 23:01:38 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [63/83] hwmon: (adm1021) Strengthen chip detection for ADM1021, LM84 and MAX1617 In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.101 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.47-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Guenter Roeck commit 591bfcfc334a003ba31c0deff03b22e73349939b upstream. On a system with both MAX1617 and JC42 sensors, JC42 sensors can be misdetected as LM84. Strengthen detection sufficiently enough to avoid this misdetection. Also improve detection for ADM1021. Modeled after chip detection code in sensors-detect command. Signed-off-by: Guenter Roeck Tested-by: Jean Delvare Acked-by: Jean Delvare Signed-off-by: Ben Hutchings --- drivers/hwmon/adm1021.c | 58 ++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 50 insertions(+), 8 deletions(-) --- a/drivers/hwmon/adm1021.c +++ b/drivers/hwmon/adm1021.c @@ -311,26 +311,68 @@ static int adm1021_detect(struct i2c_cli 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 - && (config & 0x7F) == 0x00 - && (status & 0xAB) == 0x00) - type_name = "lm84"; - else - type_name = "max1617"; + 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) { + type_name = "lm84"; + } else { + /* fail if low limits are larger than high limits */ + if ((s8)llo > lhi || (s8)rlo > rhi) + return -ENODEV; + type_name = "max1617"; + } + } pr_debug("adm1021: Detected chip %s at adapter %d, address 0x%02x.\n", type_name, i2c_adapter_id(adapter), client->addr);