--- /dev/null
+/* 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)
+ 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",
+ },
+ .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");
Code Review / kvmfornfv.git / blobdiff