drivers:hwmon: Add FS1606 driver for SP8 VR

drivers/hwmon/pmbus/Kconfig

@@ -608,4 +608,17 @@ config SENSORS_FAN251030
 	  be called fan251015,fan251030.
 
 
+config SENSORS_FS1606A
+        tristate "TDK FS1606A Digital µPOL"
+        depends on I2C
+        help
+          If you say yes here you get hardware monitoring support for the
+          TDK FS1606A digital micro point-of-load (µPOL) power module.
+
+          The device provides input voltage (PVIN), output voltage (VOUT),
+          output current (IOUT), and temperature measurements via I2C.
+
+          This driver can also be built as a module. If so, the module will
+          be called fs1606a.
+
 endif # PMBUS

drivers/hwmon/pmbus/Makefile

@@ -12,6 +12,7 @@ obj-$(CONFIG_SENSORS_BEL_PFE)	+= bel-pfe.o
 obj-$(CONFIG_SENSORS_BPA_RS600)	+= bpa-rs600.o
 obj-$(CONFIG_SENSORS_DELTA_AHE50DC_FAN) += delta-ahe50dc-fan.o
 obj-$(CONFIG_SENSORS_FSP_3Y)	+= fsp-3y.o
+obj-$(CONFIG_SENSORS_FS1606A)   += fs1606a.o
 obj-$(CONFIG_SENSORS_FAN251030) += fan251030.o
 obj-$(CONFIG_SENSORS_IBM_CFFPS)	+= ibm-cffps.o
 obj-$(CONFIG_SENSORS_DPS920AB)	+= dps920ab.o

drivers/hwmon/pmbus/fs1606a.c

@@ -0,0 +1,164 @@
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+
+/* FS1606A Registers */
+#define FS1606A_REG_PVIN   0x0C
+#define FS1606A_REG_VOUT   0x0D
+#define FS1606A_REG_IOUT   0x0E
+#define FS1606A_REG_TEMP   0x0F
+
+struct fs1606a_data {
+	struct i2c_client *client;
+};
+
+static int fs1606a_read_reg(struct i2c_client *client, u8 reg)
+{
+	u8 buf[1];
+	struct i2c_msg msgs[2] = {
+		{
+			.addr = client->addr,
+			.flags = 0, /* Write register address */
+			.len = 1,
+			.buf = &reg,
+		},
+		{
+			.addr = client->addr,
+			.flags = I2C_M_RD, /* Read 1 byte data */
+			.len = 1,
+			.buf = buf,
+		}
+	};
+	int ret;
+
+	ret = i2c_transfer(client->adapter, msgs, 2);
+	if (ret == 2)
+		return buf[0];
+
+	return ret < 0 ? ret : -EIO;
+}
+
+static int fs1606a_read(struct device *dev, enum hwmon_sensor_types type,
+			u32 attr, int channel, long *val)
+{
+	struct fs1606a_data *data = dev_get_drvdata(dev);
+	int reg_val;
+
+	switch (type) {
+	case hwmon_in:
+		if (channel == 0) { /* PVIN */
+			reg_val = fs1606a_read_reg(data->client, FS1606A_REG_PVIN);
+			if (reg_val < 0)
+				return reg_val;
+			/* Resolution 1/16 V, hwmon wants mV */
+			*val = (reg_val * 1000) / 16;
+		} else if (channel == 1) { /* VOUT */
+			reg_val = fs1606a_read_reg(data->client, FS1606A_REG_VOUT);
+			if (reg_val < 0)
+				return reg_val;
+			/* VOUT = (reg_val * 10) + 300 mV (Standard) */
+			*val = (reg_val * 10) + 300;
+		} else {
+			return -EOPNOTSUPP;
+		}
+		break;
+	case hwmon_curr: /* IOUT */
+		reg_val = fs1606a_read_reg(data->client, FS1606A_REG_IOUT);
+		if (reg_val < 0)
+			return reg_val;
+		/* Resolution 1/32 A, hwmon wants mA */
+		*val = (reg_val * 1000) / 32;
+		break;
+	case hwmon_temp: /* Temperature */
+		reg_val = fs1606a_read_reg(data->client, FS1606A_REG_TEMP);
+		if (reg_val < 0)
+			return reg_val;
+		/* Resolution 1 degC, hwmon wants millidegrees C */
+		*val = reg_val * 1000;
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static umode_t fs1606a_is_visible(const void *data, enum hwmon_sensor_types type,
+				  u32 attr, int channel)
+{
+	switch (type) {
+	case hwmon_in:
+		if (channel == 0 || channel == 1)
+			return 0444;
+		break;
+	case hwmon_curr:
+	case hwmon_temp:
+		return 0444;
+	default:
+		break;
+	}
+	return 0;
+}
+
+static const struct hwmon_channel_info *const fs1606a_info[] = {
+	HWMON_CHANNEL_INFO(in, HWMON_I_INPUT, HWMON_I_INPUT),
+	HWMON_CHANNEL_INFO(curr, HWMON_C_INPUT),
+	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
+	NULL
+};
+
+static const struct hwmon_chip_info fs1606a_chip_info = {
+	.ops = &(const struct hwmon_ops){
+		.is_visible = fs1606a_is_visible,
+		.read = fs1606a_read,
+	},
+	.info = fs1606a_info,
+};
+
+static int fs1606a_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct fs1606a_data *data;
+	struct device *hwmon_dev;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->client = client;
+
+	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
+							 data, &fs1606a_chip_info,
+							 NULL);
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct i2c_device_id fs1606a_id[] = {
+	{ "fs1606a", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, fs1606a_id);
+
+static const struct of_device_id fs1606a_of_match[] = {
+	{ .compatible = "tdk,fs1606a" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, fs1606a_of_match);
+
+static struct i2c_driver fs1606a_driver = {
+	.driver = {
+		.name = "fs1606a",
+		.of_match_table = fs1606a_of_match,
+	},
+	.probe = fs1606a_probe,
+	.id_table = fs1606a_id,
+};
+
+module_i2c_driver(fs1606a_driver);
+
+MODULE_AUTHOR("Bobby");
+MODULE_DESCRIPTION("TDK FS1606A HWMON Driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(PMBUS);