staging:iio::hwmon interface client driver. (e0f8a24e) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/staging/iio/Kconfig

+7 −0

Original line number	Diff line number	Diff line
		@@ -11,6 +11,13 @@ menuconfig IIO
		number of different physical interfaces (i2c, spi, etc). See
		drivers/staging/iio/Documentation for more information.
		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
		bool "Enable buffer support within IIO"

drivers/staging/iio/Makefile

+2 −0

Original line number	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_ST_HWMON) += iio_hwmon.o

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

drivers/staging/iio/iio_hwmon.c

0 → 100644

+232 −0

Original line number	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");