hwmon: (pmbus) Add support for Texas Instruments tps53679 device

The below lists of VOUT_MODE command readout with their related VID
protocols, Digital to Analog Converter steps, supported by the device:
VR12.0 mode, 5-mV DAC - 0x21
VR12.5 mode, 10-mV DAC - 0x22
VR13.0 mode, 10-mV DAC - 0x24
IMVP8 mode, 5-mV DAC - 0x25
VR13.0 mode, 5-mV DAC - 0x27

Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/pmbus/Kconfig

@@ -144,6 +144,15 @@ config SENSORS_TPS40422
 	  This driver can also be built as a module. If so, the module will
 	  be called tps40422.
 
+config SENSORS_TPS53679
+	tristate "TI TPS53679"
+	help
+	  If you say yes here you get hardware monitoring support for TI
+	  TPS53679.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called tps53679.
+
 config SENSORS_UCD9000
 	tristate "TI UCD90120, UCD90124, UCD90160, UCD9090, UCD90910"
 	default n

drivers/hwmon/pmbus/Makefile

@@ -15,6 +15,7 @@ obj-$(CONFIG_SENSORS_MAX20751)	+= max20751.o
 obj-$(CONFIG_SENSORS_MAX34440)	+= max34440.o
 obj-$(CONFIG_SENSORS_MAX8688)	+= max8688.o
 obj-$(CONFIG_SENSORS_TPS40422)	+= tps40422.o
+obj-$(CONFIG_SENSORS_TPS53679)	+= tps53679.o
 obj-$(CONFIG_SENSORS_UCD9000)	+= ucd9000.o
 obj-$(CONFIG_SENSORS_UCD9200)	+= ucd9200.o
 obj-$(CONFIG_SENSORS_ZL6100)	+= zl6100.o

drivers/hwmon/pmbus/tps53679.c

@@ -0,0 +1,113 @@
+/*
+ * Hardware monitoring driver for Texas Instruments TPS53679
+ *
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Vadim Pasternak <vadimp@mellanox.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include "pmbus.h"
+
+#define TPS53679_PROT_VR12_5MV		0x01 /* VR12.0 mode, 5-mV DAC */
+#define TPS53679_PROT_VR12_5_10MV	0x02 /* VR12.5 mode, 10-mV DAC */
+#define TPS53679_PROT_VR13_10MV		0x04 /* VR13.0 mode, 10-mV DAC */
+#define TPS53679_PROT_IMVP8_5MV		0x05 /* IMVP8 mode, 5-mV DAC */
+#define TPS53679_PROT_VR13_5MV		0x07 /* VR13.0 mode, 5-mV DAC */
+#define TPS53679_PAGE_NUM		2
+
+static int tps53679_identify(struct i2c_client *client,
+			     struct pmbus_driver_info *info)
+{
+	u8 vout_params;
+	int ret;
+
+	/* Read the register with VOUT scaling value.*/
+	ret = pmbus_read_byte_data(client, 0, PMBUS_VOUT_MODE);
+	if (ret < 0)
+		return ret;
+
+	vout_params = ret & GENMASK(4, 0);
+
+	switch (vout_params) {
+	case TPS53679_PROT_VR13_10MV:
+	case TPS53679_PROT_VR12_5_10MV:
+		info->vrm_version = vr13;
+		break;
+	case TPS53679_PROT_VR13_5MV:
+	case TPS53679_PROT_VR12_5MV:
+	case TPS53679_PROT_IMVP8_5MV:
+		info->vrm_version = vr12;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static struct pmbus_driver_info tps53679_info = {
+	.pages = TPS53679_PAGE_NUM,
+	.format[PSC_VOLTAGE_IN] = linear,
+	.format[PSC_VOLTAGE_OUT] = vid,
+	.format[PSC_TEMPERATURE] = linear,
+	.format[PSC_CURRENT_OUT] = linear,
+	.format[PSC_POWER] = linear,
+	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
+		PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
+		PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP |
+		PMBUS_HAVE_POUT,
+	.func[1] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
+		PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
+		PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP |
+		PMBUS_HAVE_POUT,
+	.identify = tps53679_identify,
+};
+
+static int tps53679_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
+{
+	return pmbus_do_probe(client, id, &tps53679_info);
+}
+
+static const struct i2c_device_id tps53679_id[] = {
+	{"tps53679", 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(i2c, tps53679_id);
+
+static const struct of_device_id tps53679_of_match[] = {
+	{.compatible = "ti,tps53679"},
+	{}
+};
+MODULE_DEVICE_TABLE(of, tps53679_of_match);
+
+static struct i2c_driver tps53679_driver = {
+	.driver = {
+		.name = "tps53679",
+		.of_match_table = of_match_ptr(tps53679_of_match),
+	},
+	.probe = tps53679_probe,
+	.remove = pmbus_do_remove,
+	.id_table = tps53679_id,
+};
+
+module_i2c_driver(tps53679_driver);
+
+MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
+MODULE_DESCRIPTION("PMBus driver for Texas Instruments TPS53679");
+MODULE_LICENSE("GPL");