hwmon: (nct6683) Support NCT6687D.

This is found on many MSI motherboards.
Signed-off-by: David Bartley <andareed@gmail.com>
Link: https://lore.kernel.org/r/20201202025057.5492-1-andareed@gmail.comSigned-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/nct6683.rst

@@ -3,7 +3,7 @@ Kernel driver nct6683
 
 Supported chips:
 
-  * Nuvoton NCT6683D
+  * Nuvoton NCT6683D/NCT6687D
 
     Prefix: 'nct6683'
 
@@ -61,4 +61,5 @@ Board		Firmware version
 Intel DH87RL	NCT6683D EC firmware version 1.0 build 04/03/13
 Intel DH87MC	NCT6683D EC firmware version 1.0 build 04/03/13
 Intel DB85FL	NCT6683D EC firmware version 1.0 build 04/03/13
+MSI B550	NCT6687D EC firmware version 1.0 build 05/07/20
 =============== ===============================================

drivers/hwmon/nct6683.c

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * nct6683 - Driver for the hardware monitoring functionality of
- *	     Nuvoton NCT6683D eSIO
+ *	     Nuvoton NCT6683D/NCT6687D eSIO
  *
  * Copyright (C) 2013  Guenter Roeck <linux@roeck-us.net>
  *
@@ -12,6 +12,7 @@
  *
  * Chip        #vin    #fan    #pwm    #temp  chip ID
  * nct6683d     21(1)   16      8       32(1) 0xc730
+ * nct6687d     21(1)   16      8       32(1) 0xd590
  *
  * Notes:
  *	(1) Total number of vin and temp inputs is 32.
@@ -32,7 +33,7 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 
-enum kinds { nct6683 };
+enum kinds { nct6683, nct6687 };
 
 static bool force;
 module_param(force, bool, 0);
@@ -40,10 +41,12 @@ MODULE_PARM_DESC(force, "Set to one to enable support for unknown vendors");
 
 static const char * const nct6683_device_names[] = {
 	"nct6683",
+	"nct6687",
 };
 
 static const char * const nct6683_chip_names[] = {
 	"NCT6683D",
+	"NCT6687D",
 };
 
 #define DRVNAME "nct6683"
@@ -63,6 +66,7 @@ static const char * const nct6683_chip_names[] = {
 
 #define SIO_NCT6681_ID		0xb270	/* for later */
 #define SIO_NCT6683_ID		0xc730
+#define SIO_NCT6687_ID		0xd590
 #define SIO_ID_MASK		0xFFF0
 
 static inline void
@@ -164,6 +168,7 @@ superio_exit(int ioreg)
 #define NCT6683_REG_CUSTOMER_ID		0x602
 #define NCT6683_CUSTOMER_ID_INTEL	0x805
 #define NCT6683_CUSTOMER_ID_MITAC	0xa0e
+#define NCT6683_CUSTOMER_ID_MSI		0x201
 
 #define NCT6683_REG_BUILD_YEAR		0x604
 #define NCT6683_REG_BUILD_MONTH		0x605
@@ -1218,6 +1223,8 @@ static int nct6683_probe(struct platform_device *pdev)
 		break;
 	case NCT6683_CUSTOMER_ID_MITAC:
 		break;
+	case NCT6683_CUSTOMER_ID_MSI:
+		break;
 	default:
 		if (!force)
 			return -ENODEV;
@@ -1352,6 +1359,9 @@ static int __init nct6683_find(int sioaddr, struct nct6683_sio_data *sio_data)
 	case SIO_NCT6683_ID:
 		sio_data->kind = nct6683;
 		break;
+	case SIO_NCT6687_ID:
+		sio_data->kind = nct6687;
+		break;
 	default:
 		if (val != 0xffff)
 			pr_debug("unsupported chip ID: 0x%04x\n", val);