drivers/hwmon/wm831x-hwmon.c

Source file repositories/reference/linux-study-clean/drivers/hwmon/wm831x-hwmon.c

File Facts

System
Linux kernel
Corpus path
drivers/hwmon/wm831x-hwmon.c
Extension
.c
Size
4455 bytes
Lines
154
Domain
Driver Families
Bucket
drivers/hwmon
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 * drivers/hwmon/wm831x-hwmon.c - Wolfson Microelectronics WM831x PMIC
 *                                hardware monitoring features.
 *
 * Copyright (C) 2009 Wolfson Microelectronics plc
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/slab.h>

#include <linux/mfd/wm831x/core.h>
#include <linux/mfd/wm831x/auxadc.h>

static const char * const input_names[] = {
	[WM831X_AUX_SYSVDD]    = "SYSVDD",
	[WM831X_AUX_USB]       = "USB",
	[WM831X_AUX_BKUP_BATT] = "Backup battery",
	[WM831X_AUX_BATT]      = "Battery",
	[WM831X_AUX_WALL]      = "WALL",
	[WM831X_AUX_CHIP_TEMP] = "PMIC",
	[WM831X_AUX_BATT_TEMP] = "Battery",
};

static ssize_t show_voltage(struct device *dev,
			    struct device_attribute *attr, char *buf)
{
	struct wm831x *wm831x = dev_get_drvdata(dev);
	int channel = to_sensor_dev_attr(attr)->index;
	int ret;

	ret = wm831x_auxadc_read_uv(wm831x, channel);
	if (ret < 0)
		return ret;

	return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(ret, 1000));
}

static ssize_t show_chip_temp(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
	struct wm831x *wm831x = dev_get_drvdata(dev);
	int channel = to_sensor_dev_attr(attr)->index;
	int ret;

	ret = wm831x_auxadc_read(wm831x, channel);
	if (ret < 0)
		return ret;

	/* Degrees celsius = (512.18-ret) / 1.0983 */
	ret = 512180 - (ret * 1000);
	ret = DIV_ROUND_CLOSEST(ret * 10000, 10983);

	return sprintf(buf, "%d\n", ret);
}

static ssize_t show_label(struct device *dev,
			  struct device_attribute *attr, char *buf)
{
	int channel = to_sensor_dev_attr(attr)->index;

	return sprintf(buf, "%s\n", input_names[channel]);
}

#define WM831X_VOLTAGE(id, name) \
	static SENSOR_DEVICE_ATTR(in##id##_input, S_IRUGO, show_voltage, \
				  NULL, name)

#define WM831X_NAMED_VOLTAGE(id, name) \
	WM831X_VOLTAGE(id, name); \
	static SENSOR_DEVICE_ATTR(in##id##_label, S_IRUGO, show_label,	\
				  NULL, name)

WM831X_VOLTAGE(0, WM831X_AUX_AUX1);
WM831X_VOLTAGE(1, WM831X_AUX_AUX2);
WM831X_VOLTAGE(2, WM831X_AUX_AUX3);
WM831X_VOLTAGE(3, WM831X_AUX_AUX4);

WM831X_NAMED_VOLTAGE(4, WM831X_AUX_SYSVDD);
WM831X_NAMED_VOLTAGE(5, WM831X_AUX_USB);
WM831X_NAMED_VOLTAGE(6, WM831X_AUX_BATT);
WM831X_NAMED_VOLTAGE(7, WM831X_AUX_WALL);
WM831X_NAMED_VOLTAGE(8, WM831X_AUX_BKUP_BATT);

static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_chip_temp, NULL,

Annotation

Implementation Notes