ARM: HWMON: S3C24XX series ADC driver (bff78650) · Commits · e / devices / android_kernel_teracube_2e

arch/arm/plat-s3c/include/plat/hwmon.h

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		/* linux/arch/arm/plat-s3c/include/plat/hwmon.h
		*
		* Copyright 2005 Simtec Electronics
		* Ben Dooks <ben@simtec.co.uk>
		* http://armlinux.simtec.co.uk/
		*
		* S3C - HWMon interface for ADC
		*
		* 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.
		*/

		#ifndef __ASM_ARCH_ADC_HWMON_H
		#define __ASM_ARCH_ADC_HWMON_H __FILE__

		/**
		* s3c_hwmon_chcfg - channel configuration
		* @name: The name to give this channel.
		* @mult: Multiply the ADC value read by this.
		* @div: Divide the value from the ADC by this.
		*
		* The value read from the ADC is converted to a value that
		* hwmon expects (mV) by result = (value_read * @mult) / @div.
		*/
		struct s3c_hwmon_chcfg {
		const char *name;
		unsigned int mult;
		unsigned int div;
		};

		/**
		* s3c_hwmon_pdata - HWMON platform data
		* @in: One configuration for each possible channel used.
		*/
		struct s3c_hwmon_pdata {
		struct s3c_hwmon_chcfg *in[8];
		};

		#endif /* __ASM_ARCH_ADC_HWMON_H */

drivers/hwmon/Kconfig

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		@@ -702,6 +702,23 @@ config SENSORS_SHT15
		This driver can also be built as a module. If so, the module
		will be called sht15.

		config SENSORS_S3C
		tristate "S3C24XX/S3C64XX Inbuilt ADC"
		depends on ARCH_S3C2410 \|\| ARCH_S3C64XX
		help
		If you say yes here you get support for the on-board ADCs of
		the Samsung S3C24XX or S3C64XX series of SoC

		This driver can also be built as a module. If so, the module
		will be called s3c-hwmo.

		config SENSORS_S3C_RAW
		bool "Include raw channel attributes in sysfs"
		depends on SENSORS_S3C
		help
		Say Y here if you want to include raw copies of all the ADC
		channels in sysfs.

		config SENSORS_SIS5595
		tristate "Silicon Integrated Systems Corp. SiS5595"
		depends on PCI

drivers/hwmon/Makefile

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		@@ -76,6 +76,7 @@ obj-$(CONFIG_SENSORS_MAX6650) += max6650.o
		obj-$(CONFIG_SENSORS_PC87360) += pc87360.o
		obj-$(CONFIG_SENSORS_PC87427) += pc87427.o
		obj-$(CONFIG_SENSORS_PCF8591) += pcf8591.o
		obj-$(CONFIG_SENSORS_S3C) += s3c-hwmon.o
		obj-$(CONFIG_SENSORS_SHT15) += sht15.o
		obj-$(CONFIG_SENSORS_SIS5595) += sis5595.o
		obj-$(CONFIG_SENSORS_SMSC47B397)+= smsc47b397.o

drivers/hwmon/s3c-hwmon.c

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		/* linux/drivers/hwmon/s3c-hwmon.c
		*
		* Copyright (C) 2005, 2008, 2009 Simtec Electronics
		* http://armlinux.simtec.co.uk/
		* Ben Dooks <ben@simtec.co.uk>
		*
		* S3C24XX/S3C64XX ADC hwmon support
		*
		* 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.
		*
		* 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.
		*
		* You should have received a copy of the GNU General Public License
		* along with this program; if not, write to the Free Software
		* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
		*/

		#include <linux/module.h>
		#include <linux/slab.h>
		#include <linux/delay.h>
		#include <linux/io.h>
		#include <linux/init.h>
		#include <linux/err.h>
		#include <linux/clk.h>
		#include <linux/interrupt.h>
		#include <linux/platform_device.h>

		#include <linux/hwmon.h>
		#include <linux/hwmon-sysfs.h>

		#include <plat/adc.h>
		#include <plat/hwmon.h>

		struct s3c_hwmon_attr {
		struct sensor_device_attribute in;
		struct sensor_device_attribute label;
		char in_name[12];
		char label_name[12];
		};

		/**
		* struct s3c_hwmon - ADC hwmon client information
		* @lock: Access lock to serialise the conversions.
		* @client: The client we registered with the S3C ADC core.
		* @hwmon_dev: The hwmon device we created.
		* @attr: The holders for the channel attributes.
		*/
		struct s3c_hwmon {
		struct semaphore lock;
		struct s3c_adc_client *client;
		struct device *hwmon_dev;

		struct s3c_hwmon_attr attrs[8];
		};

		/**
		* s3c_hwmon_read_ch - read a value from a given adc channel.
		* @dev: The device.
		* @hwmon: Our state.
		* @channel: The channel we're reading from.
		*
		* Read a value from the @channel with the proper locking and sleep until
		* either the read completes or we timeout awaiting the ADC core to get
		* back to us.
		*/
		static int s3c_hwmon_read_ch(struct device *dev,
		struct s3c_hwmon *hwmon, int channel)
		{
		int ret;

		ret = down_interruptible(&hwmon->lock);
		if (ret < 0)
		return ret;

		dev_dbg(dev, "reading channel %d\n", channel);

		ret = s3c_adc_read(hwmon->client, channel);
		up(&hwmon->lock);

		return ret;
		}

		#ifdef CONFIG_SENSORS_S3C_RAW
		/**
		* s3c_hwmon_show_raw - show a conversion from the raw channel number.
		* @dev: The device that the attribute belongs to.
		* @attr: The attribute being read.
		* @buf: The result buffer.
		*
		* This show deals with the raw attribute, registered for each possible
		* ADC channel. This does a conversion and returns the raw (un-scaled)
		* value returned from the hardware.
		*/
		static ssize_t s3c_hwmon_show_raw(struct device *dev,
		struct device_attribute attr, char buf)
		{
		struct s3c_hwmon *adc = platform_get_drvdata(to_platform_device(dev));
		struct sensor_device_attribute *sa = to_sensor_dev_attr(attr);
		int ret;

		ret = s3c_hwmon_read_ch(dev, adc, sa->index);

		return (ret < 0) ? ret : snprintf(buf, PAGE_SIZE, "%d\n", ret);
		}

		#define DEF_ADC_ATTR(x) \
		static SENSOR_DEVICE_ATTR(adc##x##_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, x)

		DEF_ADC_ATTR(0);
		DEF_ADC_ATTR(1);
		DEF_ADC_ATTR(2);
		DEF_ADC_ATTR(3);
		DEF_ADC_ATTR(4);
		DEF_ADC_ATTR(5);
		DEF_ADC_ATTR(6);
		DEF_ADC_ATTR(7);

		static struct attribute *s3c_hwmon_attrs[9] = {
		&sensor_dev_attr_adc0_raw.dev_attr.attr,
		&sensor_dev_attr_adc1_raw.dev_attr.attr,
		&sensor_dev_attr_adc2_raw.dev_attr.attr,
		&sensor_dev_attr_adc3_raw.dev_attr.attr,
		&sensor_dev_attr_adc4_raw.dev_attr.attr,
		&sensor_dev_attr_adc5_raw.dev_attr.attr,
		&sensor_dev_attr_adc6_raw.dev_attr.attr,
		&sensor_dev_attr_adc7_raw.dev_attr.attr,
		NULL,
		};

		static struct attribute_group s3c_hwmon_attrgroup = {
		.attrs = s3c_hwmon_attrs,
		};

		static inline int s3c_hwmon_add_raw(struct device *dev)
		{
		return sysfs_create_group(&dev->kobj, &s3c_hwmon_attrgroup);
		}

		static inline void s3c_hwmon_remove_raw(struct device *dev)
		{
		sysfs_remove_group(&dev->kobj, &s3c_hwmon_attrgroup);
		}

		#else

		static inline int s3c_hwmon_add_raw(struct device *dev) { return 0; }
		static inline void s3c_hwmon_remove_raw(struct device *dev) { }

		#endif /* CONFIG_SENSORS_S3C_RAW */

		/**
		* s3c_hwmon_ch_show - show value of a given channel
		* @dev: The device that the attribute belongs to.
		* @attr: The attribute being read.
		* @buf: The result buffer.
		*
		* Read a value from the ADC and scale it before returning it to the
		* caller. The scale factor is gained from the channel configuration
		* passed via the platform data when the device was registered.
		*/
		static ssize_t s3c_hwmon_ch_show(struct device *dev,
		struct device_attribute *attr,
		char *buf)
		{
		struct sensor_device_attribute *sen_attr = to_sensor_dev_attr(attr);
		struct s3c_hwmon *hwmon = platform_get_drvdata(to_platform_device(dev));
		struct s3c_hwmon_pdata *pdata = dev->platform_data;
		struct s3c_hwmon_chcfg *cfg;
		int ret;

		cfg = pdata->in[sen_attr->index];

		ret = s3c_hwmon_read_ch(dev, hwmon, sen_attr->index);
		if (ret < 0)
		return ret;

		ret *= cfg->mult;
		ret = DIV_ROUND_CLOSEST(ret, cfg->div);

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

		/**
		* s3c_hwmon_label_show - show label name of the given channel.
		* @dev: The device that the attribute belongs to.
		* @attr: The attribute being read.
		* @buf: The result buffer.
		*
		* Return the label name of a given channel
		*/
		static ssize_t s3c_hwmon_label_show(struct device *dev,
		struct device_attribute *attr,
		char *buf)
		{
		struct sensor_device_attribute *sen_attr = to_sensor_dev_attr(attr);
		struct s3c_hwmon_pdata *pdata = dev->platform_data;
		struct s3c_hwmon_chcfg *cfg;

		cfg = pdata->in[sen_attr->index];

		return snprintf(buf, PAGE_SIZE, "%s\n", cfg->name);
		}

		/**
		* s3c_hwmon_create_attr - create hwmon attribute for given channel.
		* @dev: The device to create the attribute on.
		* @cfg: The channel configuration passed from the platform data.
		* @channel: The ADC channel number to process.
		*
		* Create the scaled attribute for use with hwmon from the specified
		* platform data in @pdata. The sysfs entry is handled by the routine
		* s3c_hwmon_ch_show().
		*
		* The attribute name is taken from the configuration data if present
		* otherwise the name is taken by concatenating in_ with the channel
		* number.
		*/
		static int s3c_hwmon_create_attr(struct device *dev,
		struct s3c_hwmon_chcfg *cfg,
		struct s3c_hwmon_attr *attrs,
		int channel)
		{
		struct sensor_device_attribute *attr;
		int ret;

		snprintf(attrs->in_name, sizeof(attrs->in_name), "in%d_input", channel);

		attr = &attrs->in;
		attr->index = channel;
		attr->dev_attr.attr.name = attrs->in_name;
		attr->dev_attr.attr.mode = S_IRUGO;
		attr->dev_attr.attr.owner = THIS_MODULE;
		attr->dev_attr.show = s3c_hwmon_ch_show;

		ret = device_create_file(dev, &attr->dev_attr);
		if (ret < 0) {
		dev_err(dev, "failed to create input attribute\n");
		return ret;
		}

		/* if this has a name, add a label */
		if (cfg->name) {
		snprintf(attrs->label_name, sizeof(attrs->label_name),
		"in%d_label", channel);

		attr = &attrs->label;
		attr->index = channel;
		attr->dev_attr.attr.name = attrs->label_name;
		attr->dev_attr.attr.mode = S_IRUGO;
		attr->dev_attr.attr.owner = THIS_MODULE;
		attr->dev_attr.show = s3c_hwmon_label_show;

		ret = device_create_file(dev, &attr->dev_attr);
		if (ret < 0) {
		device_remove_file(dev, &attrs->in.dev_attr);
		dev_err(dev, "failed to create label attribute\n");
		}
		}

		return ret;
		}

		static void s3c_hwmon_remove_attr(struct device *dev,
		struct s3c_hwmon_attr *attrs)
		{
		device_remove_file(dev, &attrs->in.dev_attr);
		device_remove_file(dev, &attrs->label.dev_attr);
		}

		/**
		* s3c_hwmon_probe - device probe entry.
		* @dev: The device being probed.
		*/
		static int __devinit s3c_hwmon_probe(struct platform_device *dev)
		{
		struct s3c_hwmon_pdata *pdata = dev->dev.platform_data;
		struct s3c_hwmon *hwmon;
		int ret = 0;
		int i;

		if (!pdata) {
		dev_err(&dev->dev, "no platform data supplied\n");
		return -EINVAL;
		}

		hwmon = kzalloc(sizeof(struct s3c_hwmon), GFP_KERNEL);
		if (hwmon == NULL) {
		dev_err(&dev->dev, "no memory\n");
		return -ENOMEM;
		}

		platform_set_drvdata(dev, hwmon);

		init_MUTEX(&hwmon->lock);

		/* Register with the core ADC driver. */

		hwmon->client = s3c_adc_register(dev, NULL, NULL, 0);
		if (IS_ERR(hwmon->client)) {
		dev_err(&dev->dev, "cannot register adc\n");
		ret = PTR_ERR(hwmon->client);
		goto err_mem;
		}

		/* add attributes for our adc devices. */

		ret = s3c_hwmon_add_raw(&dev->dev);
		if (ret)
		goto err_registered;

		/* register with the hwmon core */

		hwmon->hwmon_dev = hwmon_device_register(&dev->dev);
		if (IS_ERR(hwmon->hwmon_dev)) {
		dev_err(&dev->dev, "error registering with hwmon\n");
		ret = PTR_ERR(hwmon->hwmon_dev);
		goto err_raw_attribute;
		}

		for (i = 0; i < ARRAY_SIZE(pdata->in); i++) {
		if (!pdata->in[i])
		continue;

		if (pdata->in[i]->mult >= 0x10000)
		dev_warn(&dev->dev,
		"channel %d multiplier too large\n",
		i);

		ret = s3c_hwmon_create_attr(&dev->dev, pdata->in[i],
		&hwmon->attrs[i], i);
		if (ret) {
		dev_err(&dev->dev,
		"error creating channel %d\n", i);

		for (i--; i >= 0; i--)
		s3c_hwmon_remove_attr(&dev->dev,
		&hwmon->attrs[i]);

		goto err_hwmon_register;
		}
		}

		return 0;

		err_hwmon_register:
		hwmon_device_unregister(hwmon->hwmon_dev);

		err_raw_attribute:
		s3c_hwmon_remove_raw(&dev->dev);

		err_registered:
		s3c_adc_release(hwmon->client);

		err_mem:
		kfree(hwmon);
		return ret;
		}

		static int __devexit s3c_hwmon_remove(struct platform_device *dev)
		{
		struct s3c_hwmon *hwmon = platform_get_drvdata(dev);
		int i;

		s3c_hwmon_remove_raw(&dev->dev);

		for (i = 0; i < ARRAY_SIZE(hwmon->attrs); i++)
		s3c_hwmon_remove_attr(&dev->dev, &hwmon->attrs[i]);

		hwmon_device_unregister(hwmon->hwmon_dev);
		s3c_adc_release(hwmon->client);

		return 0;
		}

		static struct platform_driver s3c_hwmon_driver = {
		.driver = {
		.name = "s3c-hwmon",
		.owner = THIS_MODULE,
		},
		.probe = s3c_hwmon_probe,
		.remove = __devexit_p(s3c_hwmon_remove),
		};

		static int __init s3c_hwmon_init(void)
		{
		return platform_driver_register(&s3c_hwmon_driver);
		}

		static void __exit s3c_hwmon_exit(void)
		{
		platform_driver_unregister(&s3c_hwmon_driver);
		}

		module_init(s3c_hwmon_init);
		module_exit(s3c_hwmon_exit);

		MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
		MODULE_DESCRIPTION("S3C ADC HWMon driver");
		MODULE_LICENSE("GPL v2");
		MODULE_ALIAS("platform:s3c-hwmon");