staging:iio::hwmon interface client driver. (e0f8a24e) · Commits · 戴 / test

drivers/staging/iio/Kconfig

+7 −0

Original line number	Original line	Diff line number	Diff line
	@@ -11,6 +11,13 @@ menuconfig IIO
	number of different physical interfaces (i2c, spi, etc). See		number of different physical interfaces (i2c, spi, etc). See
	drivers/staging/iio/Documentation for more information.		drivers/staging/iio/Documentation for more information.
	if IIO		if IIO
			config IIO_ST_HWMON
			tristate "Hwmon driver that uses channels specified via iio maps"
			depends on HWMON
			help
			This is a platform driver that in combination with a suitable
			map allows IIO devices to provide basic hwmon functionality
			for those channels specified in the map.

	config IIO_BUFFER		config IIO_BUFFER
	bool "Enable buffer support within IIO"		bool "Enable buffer support within IIO"

drivers/staging/iio/Makefile

+2 −0

Original line number	Original line	Diff line number	Diff line
	@@ -17,6 +17,8 @@ iio_dummy-$(CONFIG_IIO_SIMPLE_DUMMY_BUFFER) += iio_simple_dummy_buffer.o

	obj-$(CONFIG_IIO_DUMMY_EVGEN) += iio_dummy_evgen.o		obj-$(CONFIG_IIO_DUMMY_EVGEN) += iio_dummy_evgen.o

			obj-$(CONFIG_IIO_ST_HWMON) += iio_hwmon.o

	obj-y += accel/		obj-y += accel/
	obj-y += adc/		obj-y += adc/
	obj-y += addac/		obj-y += addac/

drivers/staging/iio/iio_hwmon.c

0 → 100644

+232 −0

Original line number	Original line	Diff line number	Diff line
			/* Hwmon client for industrial I/O devices
			*
			* Copyright (c) 2011 Jonathan Cameron
			*
			* This program is free software; you can redistribute it and/or modify it
			* under the terms of the GNU General Public License version 2 as published by
			* the Free Software Foundation.
			*/

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

			/**
			* struct iio_hwmon_state - device instance state
			* @channels: filled with array of channels from iio
			* @num_channels: number of channels in channels (saves counting twice)
			* @hwmon_dev: associated hwmon device
			* @attr_group: the group of attributes
			* @attrs: null terminated array of attribute pointers.
			*/
			struct iio_hwmon_state {
			struct iio_channel *channels;
			int num_channels;
			struct device *hwmon_dev;
			struct attribute_group attr_group;
			struct attribute **attrs;
			};

			/*
			* Assumes that IIO and hwmon operate in the same base units.
			* This is supposed to be true, but needs verification for
			* new channel types.
			*/
			static ssize_t iio_hwmon_read_val(struct device *dev,
			struct device_attribute *attr,
			char *buf)
			{
			long result;
			int val, ret, scaleint, scalepart;
			struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr);
			struct iio_hwmon_state *state = dev_get_drvdata(dev);

			/*
			* No locking between this pair, so theoretically possible
			* the scale has changed.
			*/
			ret = iio_st_read_channel_raw(&state->channels[sattr->index],
			&val);
			if (ret < 0)
			return ret;

			ret = iio_st_read_channel_scale(&state->channels[sattr->index],
			&scaleint, &scalepart);
			if (ret < 0)
			return ret;
			switch (ret) {
			case IIO_VAL_INT:
			result = val * scaleint;
			break;
			case IIO_VAL_INT_PLUS_MICRO:
			result = (s64)val * (s64)scaleint +
			div_s64((s64)val * (s64)scalepart, 1000000LL);
			break;
			case IIO_VAL_INT_PLUS_NANO:
			result = (s64)val * (s64)scaleint +
			div_s64((s64)val * (s64)scalepart, 1000000000LL);
			break;
			default:
			return -EINVAL;
			}
			return sprintf(buf, "%ld\n", result);
			}

			static void iio_hwmon_free_attrs(struct iio_hwmon_state *st)
			{
			int i;
			struct sensor_device_attribute *a;
			for (i = 0; i < st->num_channels; i++)
			if (st->attrs[i]) {
			a = to_sensor_dev_attr(
			container_of(st->attrs[i],
			struct device_attribute,
			attr));
			kfree(a);
			}
			}

			static int __devinit iio_hwmon_probe(struct platform_device *pdev)
			{
			struct iio_hwmon_state *st;
			struct sensor_device_attribute *a;
			int ret, i;
			int in_i = 1, temp_i = 1, curr_i = 1;
			enum iio_chan_type type;

			st = kzalloc(sizeof(*st), GFP_KERNEL);
			if (st == NULL) {
			ret = -ENOMEM;
			goto error_ret;
			}

			st->channels = iio_st_channel_get_all(dev_name(&pdev->dev));
			if (IS_ERR(st->channels)) {
			ret = PTR_ERR(st->channels);
			goto error_free_state;
			}

			/* count how many attributes we have */
			while (st->channels[st->num_channels].indio_dev)
			st->num_channels++;

			st->attrs = kzalloc(sizeof(st->attrs) * (st->num_channels + 1),
			GFP_KERNEL);
			if (st->attrs == NULL) {
			ret = -ENOMEM;
			goto error_release_channels;
			}
			for (i = 0; i < st->num_channels; i++) {
			a = kzalloc(sizeof(*a), GFP_KERNEL);
			if (a == NULL) {
			ret = -ENOMEM;
			goto error_free_attrs;
			}

			sysfs_attr_init(&a->dev_attr.attr);
			ret = iio_st_get_channel_type(&st->channels[i], &type);
			if (ret < 0) {
			kfree(a);
			goto error_free_attrs;
			}
			switch (type) {
			case IIO_VOLTAGE:
			a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
			"in%d_input",
			in_i++);
			break;
			case IIO_TEMP:
			a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
			"temp%d_input",
			temp_i++);
			break;
			case IIO_CURRENT:
			a->dev_attr.attr.name = kasprintf(GFP_KERNEL,
			"curr%d_input",
			curr_i++);
			break;
			default:
			ret = -EINVAL;
			kfree(a);
			goto error_free_attrs;
			}
			if (a->dev_attr.attr.name == NULL) {
			kfree(a);
			ret = -ENOMEM;
			goto error_free_attrs;
			}
			a->dev_attr.show = iio_hwmon_read_val;
			a->dev_attr.attr.mode = S_IRUGO;
			a->index = i;
			st->attrs[i] = &a->dev_attr.attr;
			}

			st->attr_group.attrs = st->attrs;
			platform_set_drvdata(pdev, st);
			ret = sysfs_create_group(&pdev->dev.kobj, &st->attr_group);
			if (ret < 0)
			goto error_free_attrs;

			st->hwmon_dev = hwmon_device_register(&pdev->dev);
			if (IS_ERR(st->hwmon_dev)) {
			ret = PTR_ERR(st->hwmon_dev);
			goto error_remove_group;
			}
			return 0;

			error_remove_group:
			sysfs_remove_group(&pdev->dev.kobj, &st->attr_group);
			error_free_attrs:
			iio_hwmon_free_attrs(st);
			kfree(st->attrs);
			error_release_channels:
			iio_st_channel_release_all(st->channels);
			error_free_state:
			kfree(st);
			error_ret:
			return ret;
			}

			static int __devexit iio_hwmon_remove(struct platform_device *pdev)
			{
			struct iio_hwmon_state *st = platform_get_drvdata(pdev);

			hwmon_device_unregister(st->hwmon_dev);
			sysfs_remove_group(&pdev->dev.kobj, &st->attr_group);
			iio_hwmon_free_attrs(st);
			kfree(st->attrs);
			iio_st_channel_release_all(st->channels);

			return 0;
			}

			static struct platform_driver __refdata iio_hwmon_driver = {
			.driver = {
			.name = "iio_hwmon",
			.owner = THIS_MODULE,
			},
			.probe = iio_hwmon_probe,
			.remove = __devexit_p(iio_hwmon_remove),
			};

			static int iio_inkern_init(void)
			{
			return platform_driver_register(&iio_hwmon_driver);
			}
			module_init(iio_inkern_init);

			static void iio_inkern_exit(void)
			{
			platform_driver_unregister(&iio_hwmon_driver);
			}
			module_exit(iio_inkern_exit);

			MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
			MODULE_DESCRIPTION("IIO to hwmon driver");
			MODULE_LICENSE("GPL v2");

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