- 根目录:
- drivers
- hwmon
- s3c-hwmon.c
/* 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/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 <linux/platform_data/hwmon-s3c.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 mutex 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 = mutex_lock_interruptible(&hwmon->lock);
if (ret < 0)
return ret;
dev_dbg(dev, "reading channel %d\n", channel);
ret = s3c_adc_read(hwmon->client, channel);
mutex_unlock(&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);
}
static SENSOR_DEVICE_ATTR(adc0_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 0);
static SENSOR_DEVICE_ATTR(adc1_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 1);
static SENSOR_DEVICE_ATTR(adc2_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 2);
static SENSOR_DEVICE_ATTR(adc3_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 3);
static SENSOR_DEVICE_ATTR(adc4_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 4);
static SENSOR_DEVICE_ATTR(adc5_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 5);
static SENSOR_DEVICE_ATTR(adc6_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 6);
static SENSOR_DEVICE_ATTR(adc7_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 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_get_platdata(dev);
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_get_platdata(dev);
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;
sysfs_attr_init(&attr->dev_attr.attr);
attr->dev_attr.attr.name = attrs->in_name;
attr->dev_attr.attr.mode = S_IRUGO;
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;
sysfs_attr_init(&attr->dev_attr.attr);
attr->dev_attr.attr.name = attrs->label_name;
attr->dev_attr.attr.mode = S_IRUGO;
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 s3c_hwmon_probe(struct platform_device *dev)
{
struct s3c_hwmon_pdata *pdata = dev_get_platdata(&dev->dev);
struct s3c_hwmon *hwmon;
int ret = 0;
int i;
if (!pdata) {
dev_err(&dev->dev, "no platform data supplied\n");
return -EINVAL;
}
hwmon = devm_kzalloc(&dev->dev, sizeof(struct s3c_hwmon), GFP_KERNEL);
if (hwmon == NULL) {
dev_err(&dev->dev, "no memory\n");
return -ENOMEM;
}
platform_set_drvdata(dev, hwmon);
mutex_init(&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");
return PTR_ERR(hwmon->client);
}
/* 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++) {
struct s3c_hwmon_chcfg *cfg = pdata->in[i];
if (!cfg)
continue;
if (cfg->mult >= 0x10000)
dev_warn(&dev->dev,
"channel %d multiplier too large\n",
i);
if (cfg->div == 0) {
dev_err(&dev->dev, "channel %d divider zero\n", i);
continue;
}
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);
return ret;
}
static int 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 = s3c_hwmon_remove,
};
module_platform_driver(s3c_hwmon_driver);
MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
MODULE_DESCRIPTION("S3C ADC HWMon driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:s3c-hwmon");