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Sender: Guenter Roeck <groeck7@gmail.com>
From:   Guenter Roeck <linux@roeck-us.net>
To:     linux-hwmon@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org, Jean Delvare <jdelvare@suse.com>,
        Slawomir Stepien <sst@poczta.fm>,
        Guenter Roeck <linux@roeck-us.net>
Subject: [PATCH 16/40] hwmon: (lm90) Add support for additional chip revision of NCT1008
Date:   Wed, 25 May 2022 06:57:34 -0700
Message-Id: <20220525135758.2944744-17-linux@roeck-us.net>
In-Reply-To: <20220525135758.2944744-1-linux@roeck-us.net>
References: <20220525135758.2944744-1-linux@roeck-us.net>
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The NCT1008 datasheet, Revision 3, states that its chip revision is
0x57. This matches the ADT7461A chip revision, and NCT1008 is therefore
detected as ADT7461A. In revision 6 of the datasheet, the chip revision
register is no longer documented. Multiple samples of NCT1008 were found
to report a chip revision of 0x54. As it turns out, one of the patches
submitted to add NCT1008 support to the lm90 driver already included a
check for chip revision 0x54. Unfortunately, that patch never made it into
the kernel. Remedy the situation and explicitly detect chips with revision
0x54 as NCT1008.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/lm90.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index f676b809c470..17312d173b8a 100644
--- a/drivers/hwmon/lm90.c
+++ b/drivers/hwmon/lm90.c
@@ -1556,7 +1556,12 @@ static const char *lm90_detect_analog(struct i2c_client *client, int chip_id,
 		    convrate <= 0x0a)
 			name = "adt7461";
 		break;
-	case 0x57:	/* ADT7461A, NCT1008 */
+	case 0x54:	/* NCT1008 */
+		if ((address == 0x4c || address == 0x4d) && !(config1 & 0x1b) &&
+		    convrate <= 0x0a)
+			name = "nct1008";
+		break;
+	case 0x57:	/* ADT7461A, NCT1008 (datasheet rev. 3) */
 		if ((address == 0x4c || address == 0x4d) && !(config1 & 0x1b) &&
 		    convrate <= 0x0a)
 			name = "adt7461a";
-- 
2.35.1