1 files changed, 101 insertions, 0 deletions
diff --git a/drivers/hwmon/pmbus/max15301.c b/drivers/hwmon/pmbus/max15301.c
new file mode 100644
index 000000000000..d5810b88ea8d
--- /dev/null
+++ b/drivers/hwmon/pmbus/max15301.c
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Hardware monitoring driver for Maxim MAX15301
+ *
+ * Copyright (c) 2021 Flextronics International Sweden AB
+ *
+ * Even though the specification does not specifically mention it,
+ * extensive empirical testing has revealed that auto-detection of
+ * limit-registers will fail in a random fashion unless the delay
+ * parameter is set to above about 80us. The default delay is set
+ * to 100us to include some safety margin.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/ktime.h>
+#include <linux/delay.h>
+#include <linux/pmbus.h>
+#include "pmbus.h"
+
+static const struct i2c_device_id max15301_id[] = {
+	{ "bmr461" },
+	{ "max15301" },
+	{ "max15303" },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, max15301_id);
+
+struct max15301_data {
+	int id;
+	struct pmbus_driver_info info;
+};
+
+#define to_max15301_data(x)  container_of(x, struct max15301_data, info)
+
+#define MAX15301_WAIT_TIME		100	/* us	*/
+
+static ushort delay = MAX15301_WAIT_TIME;
+module_param(delay, ushort, 0644);
+MODULE_PARM_DESC(delay, "Delay between chip accesses in us");
+
+static struct max15301_data max15301_data = {
+	.info = {
+		.pages = 1,
+		.func[0] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
+			| PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
+			| PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2
+			| PMBUS_HAVE_STATUS_TEMP
+			| PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT,
+	}
+};
+
+static int max15301_probe(struct i2c_client *client)
+{
+	int status;
+	u8 device_id[I2C_SMBUS_BLOCK_MAX + 1];
+	const struct i2c_device_id *mid;
+	struct pmbus_driver_info *info = &max15301_data.info;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_READ_BYTE_DATA
+				     | I2C_FUNC_SMBUS_BLOCK_DATA))
+		return -ENODEV;
+
+	status = i2c_smbus_read_block_data(client, PMBUS_IC_DEVICE_ID, device_id);
+	if (status < 0) {
+		dev_err(&client->dev, "Failed to read Device Id\n");
+		return status;
+	}
+	for (mid = max15301_id; mid->name[0]; mid++) {
+		if (!strncasecmp(mid->name, device_id, strlen(mid->name)))
+			break;
+	}
+	if (!mid->name[0]) {
+		dev_err(&client->dev, "Unsupported device\n");
+		return -ENODEV;
+	}
+
+	info->access_delay = delay;
+
+	return pmbus_do_probe(client, info);
+}
+
+static struct i2c_driver max15301_driver = {
+	.driver = {
+		   .name = "max15301",
+		   },
+	.probe = max15301_probe,
+	.id_table = max15301_id,
+};
+
+module_i2c_driver(max15301_driver);
+
+MODULE_AUTHOR("Erik Rosen <erik.rosen@metormote.com>");
+MODULE_DESCRIPTION("PMBus driver for Maxim MAX15301");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("PMBUS");