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linux/drivers/hwmon/mc13783-adc.c
Luotao Fu 93ee0a75f6 hwmon: Add Freescale MC13783 ADC driver 
This driver provides support for the ADC integrated into the
Freescale MC13783 PMIC.

Signed-off-by: Luotao Fu <l.fu@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Cc: Eric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-12-09 20:35:58 +01:00

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/*
* Driver for the Freescale Semiconductor MC13783 adc.
*
* Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
* Copyright (C) 2009 Sascha Hauer, Pengutronix
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* 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., 51
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/mfd/mc13783-private.h>
#include <linux/platform_device.h>
#include <linux/hwmon-sysfs.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/hwmon.h>
#include <linux/init.h>
#include <linux/err.h>
#define MC13783_ADC_NAME "mc13783-adc"
struct mc13783_adc_priv {
struct mc13783 *mc13783;
struct device *hwmon_dev;
};
static ssize_t mc13783_adc_show_name(struct device *dev, struct device_attribute
*devattr, char *buf)
{
return sprintf(buf, "mc13783_adc\n");
}
static int mc13783_adc_read(struct device *dev,
struct device_attribute *devattr, unsigned int *val)
{
struct platform_device *pdev = to_platform_device(dev);
struct mc13783_adc_priv *priv = platform_get_drvdata(pdev);
struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
unsigned int channel = attr->index;
unsigned int sample[4];
int ret;
ret = mc13783_adc_do_conversion(priv->mc13783,
MC13783_ADC_MODE_MULT_CHAN,
channel, sample);
if (ret)
return ret;
channel &= 0x7;
*val = (sample[channel % 4] >> (channel > 3 ? 14 : 2)) & 0x3ff;
return 0;
}
static ssize_t mc13783_adc_read_bp(struct device *dev,
struct device_attribute *devattr, char *buf)
{
unsigned val;
int ret = mc13783_adc_read(dev, devattr, &val);
if (ret)
return ret;
/*
* BP (channel 2) reports with offset 2.4V to the actual value to fit
* the input range of the ADC. unit = 2.25mV = 9/4 mV.
*/
val = DIV_ROUND_CLOSEST(val * 9, 4) + 2400;
return sprintf(buf, "%u\n", val);
}
static ssize_t mc13783_adc_read_gp(struct device *dev,
struct device_attribute *devattr, char *buf)
{
unsigned val;
int ret = mc13783_adc_read(dev, devattr, &val);
if (ret)
return ret;
/*
* input range is [0, 2.3V], val has 10 bits, so each bit
* is worth 9/4 mV.
*/
val = DIV_ROUND_CLOSEST(val * 9, 4);
return sprintf(buf, "%u\n", val);
}
static DEVICE_ATTR(name, S_IRUGO, mc13783_adc_show_name, NULL);
static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, mc13783_adc_read_bp, NULL, 2);
static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, mc13783_adc_read_gp, NULL, 5);
static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, mc13783_adc_read_gp, NULL, 6);
static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, mc13783_adc_read_gp, NULL, 7);
static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, mc13783_adc_read_gp, NULL, 8);
static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, mc13783_adc_read_gp, NULL, 9);
static SENSOR_DEVICE_ATTR(in10_input, S_IRUGO, mc13783_adc_read_gp, NULL, 10);
static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, mc13783_adc_read_gp, NULL, 11);
static SENSOR_DEVICE_ATTR(in12_input, S_IRUGO, mc13783_adc_read_gp, NULL, 12);
static SENSOR_DEVICE_ATTR(in13_input, S_IRUGO, mc13783_adc_read_gp, NULL, 13);
static SENSOR_DEVICE_ATTR(in14_input, S_IRUGO, mc13783_adc_read_gp, NULL, 14);
static SENSOR_DEVICE_ATTR(in15_input, S_IRUGO, mc13783_adc_read_gp, NULL, 15);
static struct attribute *mc13783_attr[] = {
&dev_attr_name.attr,
&sensor_dev_attr_in2_input.dev_attr.attr,
&sensor_dev_attr_in5_input.dev_attr.attr,
&sensor_dev_attr_in6_input.dev_attr.attr,
&sensor_dev_attr_in7_input.dev_attr.attr,
&sensor_dev_attr_in8_input.dev_attr.attr,
&sensor_dev_attr_in9_input.dev_attr.attr,
&sensor_dev_attr_in10_input.dev_attr.attr,
&sensor_dev_attr_in11_input.dev_attr.attr,
NULL
};
static const struct attribute_group mc13783_group = {
.attrs = mc13783_attr,
};
/* last four channels may be occupied by the touchscreen */
static struct attribute *mc13783_attr_ts[] = {
&sensor_dev_attr_in12_input.dev_attr.attr,
&sensor_dev_attr_in13_input.dev_attr.attr,
&sensor_dev_attr_in14_input.dev_attr.attr,
&sensor_dev_attr_in15_input.dev_attr.attr,
NULL
};
static const struct attribute_group mc13783_group_ts = {
.attrs = mc13783_attr_ts,
};
static int __init mc13783_adc_probe(struct platform_device *pdev)
{
struct mc13783_adc_priv *priv;
int ret;
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->mc13783 = dev_get_drvdata(pdev->dev.parent);
platform_set_drvdata(pdev, priv);
/* Register sysfs hooks */
ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group);
if (ret)
goto out_err_create1;
if (!(priv->mc13783->flags & MC13783_USE_TOUCHSCREEN))
ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group_ts);
if (ret)
goto out_err_create2;
priv->hwmon_dev = hwmon_device_register(&pdev->dev);
if (IS_ERR(priv->hwmon_dev)) {
ret = PTR_ERR(priv->hwmon_dev);
dev_err(&pdev->dev,
"hwmon_device_register failed with %d.\n", ret);
goto out_err_register;
}
return 0;
out_err_register:
if (!(priv->mc13783->flags & MC13783_USE_TOUCHSCREEN))
sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts);
out_err_create2:
sysfs_remove_group(&pdev->dev.kobj, &mc13783_group);
out_err_create1:
platform_set_drvdata(pdev, NULL);
kfree(priv);
return ret;
}
static int __devexit mc13783_adc_remove(struct platform_device *pdev)
{
struct mc13783_adc_priv *priv = platform_get_drvdata(pdev);
hwmon_device_unregister(priv->hwmon_dev);
if (!(priv->mc13783->flags & MC13783_USE_TOUCHSCREEN))
sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts);
sysfs_remove_group(&pdev->dev.kobj, &mc13783_group);
platform_set_drvdata(pdev, NULL);
kfree(priv);
return 0;
}
static struct platform_driver mc13783_adc_driver = {
.remove = __devexit_p(mc13783_adc_remove),
.driver = {
.owner = THIS_MODULE,
.name = MC13783_ADC_NAME,
},
};
static int __init mc13783_adc_init(void)
{
return platform_driver_probe(&mc13783_adc_driver, mc13783_adc_probe);
}
static void __exit mc13783_adc_exit(void)
{
platform_driver_unregister(&mc13783_adc_driver);
}
module_init(mc13783_adc_init);
module_exit(mc13783_adc_exit);
MODULE_DESCRIPTION("MC13783 ADC driver");
MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" MC13783_ADC_NAME);
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