linux/drivers/hwmon/atxp1.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * atxp1.c - kernel module for setting CPU VID and general purpose
 *	     I/Os using the Attansic ATXP1 chip.
 *
 * 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.rst 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/kstrtox.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
#include <linux/slab.h>

MODULE_LICENSE(…) …;
MODULE_DESCRIPTION(…) …;
MODULE_VERSION(…) …;
MODULE_AUTHOR(…) …;

#define ATXP1_VID …
#define ATXP1_CVID …
#define ATXP1_GPIO1 …
#define ATXP1_GPIO2 …
#define ATXP1_VIDENA …
#define ATXP1_VIDMASK …
#define ATXP1_GPIO1MASK …

struct atxp1_data { … };

static struct atxp1_data *atxp1_update_device(struct device *dev)
{ … }

/* sys file functions for cpu0_vid */
static ssize_t cpu0_vid_show(struct device *dev,
			     struct device_attribute *attr, char *buf)
{ … }

static ssize_t cpu0_vid_store(struct device *dev,
			      struct device_attribute *attr, const char *buf,
			      size_t 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)
{ … }

static ssize_t gpio1_store(struct device *dev, struct device_attribute *attr,
			   const char *buf, size_t 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)
{ … }

static ssize_t gpio2_store(struct device *dev, struct device_attribute *attr,
			   const char *buf, size_t count)
{ … }

/*
 * GPIO2 data register
 * unit: Eight bit as hex (e.g. 0xff)
 */
static DEVICE_ATTR_RW(gpio2);

static struct attribute *atxp1_attrs[] = …;
ATTRIBUTE_GROUPS(…);

static int atxp1_probe(struct i2c_client *client)
{
	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[] = …;
MODULE_DEVICE_TABLE(i2c, atxp1_id);

static struct i2c_driver atxp1_driver = …;

module_i2c_driver(…) …;