hwmon: (pmbus) Add support for Infineon Multi-phase xdpe122 family controllers

Add support for devices XDPE12254, XDPE12284.

All these device support two pages.
The below lists of VOUT_MODE command readout with their related VID
protocols, Digital to Analog Converter steps, supported by these
devices:
VR12.0 mode, 5-mV DAC - 0x01;
VR12.5 mode, 10-mV DAC - 0x02;
IMVP9 mode, 5-mV DAC - 0x03;
AMD mode 6.25mV - 0x10.

Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Link: https://lore.kernel.org/r/20200113150841.17670-5-vadimp@mellanox.com
[groeck: Added missing break statement]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/pmbus/Kconfig

@@ -237,6 +237,15 @@ config SENSORS_UCD9200
 	  This driver can also be built as a module. If so, the module will
 	  be called ucd9200.
 
+config SENSORS_XDPE122
+	tristate "Infineon XDPE122 family"
+	help
+	  If you say yes here you get hardware monitoring support for Infineon
+	  XDPE12254, XDPE12284, device.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called xdpe12284.
+
 config SENSORS_ZL6100
 	tristate "Intersil ZL6100 and compatibles"
 	help

drivers/hwmon/pmbus/Makefile

@@ -27,4 +27,5 @@ 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-$(CONFIG_SENSORS_XDPE122)	+= xdpe12284.o
 obj-$(CONFIG_SENSORS_ZL6100)	+= zl6100.o

drivers/hwmon/pmbus/xdpe12284.c

@@ -0,0 +1,117 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Hardware monitoring driver for Infineon Multi-phase Digital VR Controllers
+ *
+ * Copyright (c) 2020 Mellanox Technologies. All rights reserved.
+ */
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include "pmbus.h"
+
+#define XDPE122_PROT_VR12_5MV		0x01 /* VR12.0 mode, 5-mV DAC */
+#define XDPE122_PROT_VR12_5_10MV	0x02 /* VR12.5 mode, 10-mV DAC */
+#define XDPE122_PROT_IMVP9_10MV		0x03 /* IMVP9 mode, 10-mV DAC */
+#define XDPE122_AMD_625MV		0x10 /* AMD mode 6.25mV */
+#define XDPE122_PAGE_NUM		2
+
+static int xdpe122_identify(struct i2c_client *client,
+			    struct pmbus_driver_info *info)
+{
+	u8 vout_params;
+	int i, ret;
+
+	for (i = 0; i < XDPE122_PAGE_NUM; i++) {
+		/* Read the register with VOUT scaling value.*/
+		ret = pmbus_read_byte_data(client, i, PMBUS_VOUT_MODE);
+		if (ret < 0)
+			return ret;
+
+		vout_params = ret & GENMASK(4, 0);
+
+		switch (vout_params) {
+		case XDPE122_PROT_VR12_5_10MV:
+			info->vrm_version[i] = vr13;
+			break;
+		case XDPE122_PROT_VR12_5MV:
+			info->vrm_version[i] = vr12;
+			break;
+		case XDPE122_PROT_IMVP9_10MV:
+			info->vrm_version[i] = imvp9;
+			break;
+		case XDPE122_AMD_625MV:
+			info->vrm_version[i] = amd625mv;
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static struct pmbus_driver_info xdpe122_info = {
+	.pages = XDPE122_PAGE_NUM,
+	.format[PSC_VOLTAGE_IN] = linear,
+	.format[PSC_VOLTAGE_OUT] = vid,
+	.format[PSC_TEMPERATURE] = linear,
+	.format[PSC_CURRENT_IN] = linear,
+	.format[PSC_CURRENT_OUT] = linear,
+	.format[PSC_POWER] = linear,
+	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
+		PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
+		PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP |
+		PMBUS_HAVE_POUT | PMBUS_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT,
+	.func[1] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
+		PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
+		PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP |
+		PMBUS_HAVE_POUT | PMBUS_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT,
+	.identify = xdpe122_identify,
+};
+
+static int xdpe122_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct pmbus_driver_info *info;
+
+	info = devm_kmemdup(&client->dev, &xdpe122_info, sizeof(*info),
+			    GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	return pmbus_do_probe(client, id, info);
+}
+
+static const struct i2c_device_id xdpe122_id[] = {
+	{"xdpe12254", 0},
+	{"xdpe12284", 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(i2c, xdpe122_id);
+
+static const struct of_device_id __maybe_unused xdpe122_of_match[] = {
+	{.compatible = "infineon, xdpe12254"},
+	{.compatible = "infineon, xdpe12284"},
+	{}
+};
+MODULE_DEVICE_TABLE(of, xdpe122_of_match);
+
+static struct i2c_driver xdpe122_driver = {
+	.driver = {
+		.name = "xdpe12284",
+		.of_match_table = of_match_ptr(xdpe122_of_match),
+	},
+	.probe = xdpe122_probe,
+	.remove = pmbus_do_remove,
+	.id_table = xdpe122_id,
+};
+
+module_i2c_driver(xdpe122_driver);
+
+MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
+MODULE_DESCRIPTION("PMBus driver for Infineon XDPE122 family");
+MODULE_LICENSE("GPL");