v4.19.13 snapshot.
diff --git a/drivers/hwmon/atxp1.c b/drivers/hwmon/atxp1.c
new file mode 100644
index 0000000..b7eadb5
--- /dev/null
+++ b/drivers/hwmon/atxp1.c
@@ -0,0 +1,304 @@
+/*
+ * atxp1.c - kernel module for setting CPU VID and general purpose
+ *	     I/Os using the Attansic ATXP1 chip.
+ *
+ * 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.
+ *
+ * The ATXP1 can reside on I2C addresses 0x37 or 0x4e. The chip is
+ * not auto-detected by the driver and must be instantiated explicitly.
+ * See Documentation/i2c/instantiating-devices for more information.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/jiffies.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-vid.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/sysfs.h>
+#include <linux/slab.h>
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("System voltages control via Attansic ATXP1");
+MODULE_VERSION("0.6.3");
+MODULE_AUTHOR("Sebastian Witt <se.witt@gmx.net>");
+
+#define ATXP1_VID	0x00
+#define ATXP1_CVID	0x01
+#define ATXP1_GPIO1	0x06
+#define ATXP1_GPIO2	0x0a
+#define ATXP1_VIDENA	0x20
+#define ATXP1_VIDMASK	0x1f
+#define ATXP1_GPIO1MASK	0x0f
+
+struct atxp1_data {
+	struct i2c_client *client;
+	struct mutex update_lock;
+	unsigned long last_updated;
+	u8 valid;
+	struct {
+		u8 vid;		/* VID output register */
+		u8 cpu_vid; /* VID input from CPU */
+		u8 gpio1;   /* General purpose I/O register 1 */
+		u8 gpio2;   /* General purpose I/O register 2 */
+	} reg;
+	u8 vrm;			/* Detected CPU VRM */
+};
+
+static struct atxp1_data *atxp1_update_device(struct device *dev)
+{
+	struct atxp1_data *data = dev_get_drvdata(dev);
+	struct i2c_client *client = data->client;
+
+	mutex_lock(&data->update_lock);
+
+	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
+
+		/* Update local register data */
+		data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID);
+		data->reg.cpu_vid = i2c_smbus_read_byte_data(client,
+							     ATXP1_CVID);
+		data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1);
+		data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2);
+
+		data->valid = 1;
+	}
+
+	mutex_unlock(&data->update_lock);
+
+	return data;
+}
+
+/* sys file functions for cpu0_vid */
+static ssize_t cpu0_vid_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	int size;
+	struct atxp1_data *data;
+
+	data = atxp1_update_device(dev);
+
+	size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK,
+						 data->vrm));
+
+	return size;
+}
+
+static ssize_t cpu0_vid_store(struct device *dev,
+			      struct device_attribute *attr, const char *buf,
+			      size_t count)
+{
+	struct atxp1_data *data = atxp1_update_device(dev);
+	struct i2c_client *client = data->client;
+	int vid, cvid;
+	unsigned long vcore;
+	int err;
+
+	err = kstrtoul(buf, 10, &vcore);
+	if (err)
+		return err;
+
+	vcore /= 25;
+	vcore *= 25;
+
+	/* Calculate VID */
+	vid = vid_to_reg(vcore, data->vrm);
+	if (vid < 0) {
+		dev_err(dev, "VID calculation failed.\n");
+		return vid;
+	}
+
+	/*
+	 * If output enabled, use control register value.
+	 * Otherwise original CPU VID
+	 */
+	if (data->reg.vid & ATXP1_VIDENA)
+		cvid = data->reg.vid & ATXP1_VIDMASK;
+	else
+		cvid = data->reg.cpu_vid;
+
+	/* Nothing changed, aborting */
+	if (vid == cvid)
+		return count;
+
+	dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", (int)vcore, vid);
+
+	/* Write every 25 mV step to increase stability */
+	if (cvid > vid) {
+		for (; cvid >= vid; cvid--)
+			i2c_smbus_write_byte_data(client,
+						ATXP1_VID, cvid | ATXP1_VIDENA);
+	} else {
+		for (; cvid <= vid; cvid++)
+			i2c_smbus_write_byte_data(client,
+						ATXP1_VID, cvid | ATXP1_VIDENA);
+	}
+
+	data->valid = 0;
+
+	return count;
+}
+
+/*
+ * CPU core reference voltage
+ * unit: millivolt
+ */
+static DEVICE_ATTR_RW(cpu0_vid);
+
+/* sys file functions for GPIO1 */
+static ssize_t gpio1_show(struct device *dev, struct device_attribute *attr,
+			  char *buf)
+{
+	int size;
+	struct atxp1_data *data;
+
+	data = atxp1_update_device(dev);
+
+	size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK);
+
+	return size;
+}
+
+static ssize_t gpio1_store(struct device *dev, struct device_attribute *attr,
+			   const char *buf, size_t count)
+{
+	struct atxp1_data *data = atxp1_update_device(dev);
+	struct i2c_client *client = data->client;
+	unsigned long value;
+	int err;
+
+	err = kstrtoul(buf, 16, &value);
+	if (err)
+		return err;
+
+	value &= ATXP1_GPIO1MASK;
+
+	if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) {
+		dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value);
+
+		i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value);
+
+		data->valid = 0;
+	}
+
+	return count;
+}
+
+/*
+ * GPIO1 data register
+ * unit: Four bit as hex (e.g. 0x0f)
+ */
+static DEVICE_ATTR_RW(gpio1);
+
+/* sys file functions for GPIO2 */
+static ssize_t gpio2_show(struct device *dev, struct device_attribute *attr,
+			  char *buf)
+{
+	int size;
+	struct atxp1_data *data;
+
+	data = atxp1_update_device(dev);
+
+	size = sprintf(buf, "0x%02x\n", data->reg.gpio2);
+
+	return size;
+}
+
+static ssize_t gpio2_store(struct device *dev, struct device_attribute *attr,
+			   const char *buf, size_t count)
+{
+	struct atxp1_data *data = atxp1_update_device(dev);
+	struct i2c_client *client = data->client;
+	unsigned long value;
+	int err;
+
+	err = kstrtoul(buf, 16, &value);
+	if (err)
+		return err;
+	value &= 0xff;
+
+	if (value != data->reg.gpio2) {
+		dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value);
+
+		i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value);
+
+		data->valid = 0;
+	}
+
+	return count;
+}
+
+/*
+ * GPIO2 data register
+ * unit: Eight bit as hex (e.g. 0xff)
+ */
+static DEVICE_ATTR_RW(gpio2);
+
+static struct attribute *atxp1_attrs[] = {
+	&dev_attr_gpio1.attr,
+	&dev_attr_gpio2.attr,
+	&dev_attr_cpu0_vid.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(atxp1);
+
+static int atxp1_probe(struct i2c_client *client,
+		       const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct atxp1_data *data;
+	struct device *hwmon_dev;
+
+	data = devm_kzalloc(dev, sizeof(struct atxp1_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	/* Get VRM */
+	data->vrm = vid_which_vrm();
+	if (data->vrm != 90 && data->vrm != 91) {
+		dev_err(dev, "atxp1: Not supporting VRM %d.%d\n",
+			data->vrm / 10, data->vrm % 10);
+		return -ENODEV;
+	}
+
+	data->client = client;
+	mutex_init(&data->update_lock);
+
+	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
+							   data,
+							   atxp1_groups);
+	if (IS_ERR(hwmon_dev))
+		return PTR_ERR(hwmon_dev);
+
+	dev_info(dev, "Using VRM: %d.%d\n", data->vrm / 10, data->vrm % 10);
+
+	return 0;
+};
+
+static const struct i2c_device_id atxp1_id[] = {
+	{ "atxp1", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, atxp1_id);
+
+static struct i2c_driver atxp1_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= "atxp1",
+	},
+	.probe		= atxp1_probe,
+	.id_table	= atxp1_id,
+};
+
+module_i2c_driver(atxp1_driver);