1 files changed, 132 insertions, 0 deletions
diff --git a/drivers/hwmon/pmbus/hac300s.c b/drivers/hwmon/pmbus/hac300s.c
new file mode 100644
index 000000000000..0a1d52cae91e
--- /dev/null
+++ b/drivers/hwmon/pmbus/hac300s.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// SPDX-FileCopyrightText: 2024 CERN (home.cern)
+/*
+ * Hardware monitoring driver for Hi-Tron HAC300S PSU.
+ *
+ * NOTE: The HAC300S device does not support the PMBUS_VOUT_MODE register.
+ * On top of that, it returns the Voltage output values in Linear11 which is
+ * not adhering to the PMBus specifications. (PMBus Specification Part II,
+ * Section 7.1-7.3). For that reason the PMBUS_VOUT_MODE register is being faked
+ * and returns the exponent value of the READ_VOUT register. The exponent part
+ * of the VOUT_* registers is being cleared in order to return the mantissa to
+ * the pmbus core.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pmbus.h>
+
+#include "pmbus.h"
+
+#define LINEAR11_EXPONENT_MASK GENMASK(15, 11)
+#define LINEAR11_MANTISSA_MASK GENMASK(10, 0)
+
+#define to_hac300s_data(x) container_of(x, struct hac300s_data, info)
+
+struct hac300s_data {
+	struct pmbus_driver_info info;
+	s8 exponent;
+};
+
+static int hac300s_read_byte_data(struct i2c_client *client, int page, int reg)
+{
+	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+	struct hac300s_data *data = to_hac300s_data(info);
+
+	if (reg == PMBUS_VOUT_MODE)
+		return data->exponent;
+
+	return -ENODATA;
+}
+
+static int hac300s_read_word_data(struct i2c_client *client, int page,
+				  int phase, int reg)
+{
+	int rv;
+
+	switch (reg) {
+	case PMBUS_VOUT_OV_WARN_LIMIT:
+	case PMBUS_VOUT_UV_WARN_LIMIT:
+	case PMBUS_VOUT_OV_FAULT_LIMIT:
+	case PMBUS_VOUT_UV_FAULT_LIMIT:
+	case PMBUS_MFR_VOUT_MAX:
+	case PMBUS_MFR_VOUT_MIN:
+	case PMBUS_READ_VOUT:
+		rv = pmbus_read_word_data(client, page, phase, reg);
+		return FIELD_GET(LINEAR11_MANTISSA_MASK, rv);
+	default:
+		return -ENODATA;
+	}
+}
+
+static struct pmbus_driver_info hac300s_info = {
+	.pages = 1,
+	.func[0] = PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 | \
+		   PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | \
+		   PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | \
+		   PMBUS_HAVE_POUT | PMBUS_HAVE_STATUS_TEMP,
+	.read_byte_data = hac300s_read_byte_data,
+	.read_word_data = hac300s_read_word_data,
+	.format[PSC_VOLTAGE_OUT] = linear,
+};
+
+static struct pmbus_platform_data hac300s_pdata = {
+	.flags = PMBUS_NO_CAPABILITY,
+};
+
+static int hac300s_probe(struct i2c_client *client)
+{
+	struct hac300s_data *data;
+	int rv;
+
+	data = devm_kzalloc(&client->dev, sizeof(struct hac300s_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_READ_BYTE_DATA |
+				     I2C_FUNC_SMBUS_READ_WORD_DATA))
+		return -ENODEV;
+
+	rv = i2c_smbus_read_word_data(client, PMBUS_READ_VOUT);
+	if (rv < 0)
+		return dev_err_probe(&client->dev, rv, "Failed to read vout_mode\n");
+
+	data->exponent = FIELD_GET(LINEAR11_EXPONENT_MASK, rv);
+	data->info = hac300s_info;
+	client->dev.platform_data = &hac300s_pdata;
+	return pmbus_do_probe(client, &data->info);
+}
+
+static const struct of_device_id hac300s_of_match[] = {
+	{ .compatible = "hitron,hac300s" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, hac300s_of_match);
+
+static const struct i2c_device_id hac300s_id[] = {
+	{"hac300s", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, hac300s_id);
+
+static struct i2c_driver hac300s_driver = {
+	.driver = {
+		   .name = "hac300s",
+		   .of_match_table = hac300s_of_match,
+	},
+	.probe = hac300s_probe,
+	.id_table = hac300s_id,
+
+};
+module_i2c_driver(hac300s_driver);
+
+MODULE_AUTHOR("Vasileios Amoiridis");
+MODULE_DESCRIPTION("PMBus driver for Hi-Tron HAC300S PSU");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("PMBUS");