linux/drivers/hwmon/twl4030-madc-hwmon.c

/*
 *
 * TWL4030 MADC Hwmon driver-This driver monitors the real time
 * conversion of analog signals like battery temperature,
 * battery type, battery level etc. User can ask for the conversion on a
 * particular channel using the sysfs nodes.
 *
 * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com/
 * J Keerthy <j-keerthy at ti.com>
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#include <linux/platform_device.h>
#include <linux/i2c/twl.h>
#include <linux/i2c/twl4030-madc.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>

/*
 * sysfs hook function
 */
static ssize_t madc_read(struct device *dev,
            struct device_attribute *devattr, char *buf)
{
   struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
   struct twl4030_madc_request req;
   long val;

   req.channels = (1 << attr->index);
   req.method = TWL4030_MADC_SW2;
   req.func_cb = NULL;
   val = twl4030_madc_conversion(&req);
   if (val >= 0)
       val = req.rbuf[attr->index];
   else
       return val;

   return sprintf(buf, "%ld\n", val);
}

/* sysfs nodes to read individual channels from user side */
static SENSOR_DEVICE_ATTR(in0_battery_type, S_IRUGO, madc_read, NULL, 0);
static SENSOR_DEVICE_ATTR(in1_battery_temp, S_IRUGO, madc_read, NULL, 1);
static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, madc_read, NULL, 2);
static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, madc_read, NULL, 3);
static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, madc_read, NULL, 4);
static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, madc_read, NULL, 5);
static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, madc_read, NULL, 6);
static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, madc_read, NULL, 7);
static SENSOR_DEVICE_ATTR(in8_vbus, S_IRUGO, madc_read, NULL, 8);
static SENSOR_DEVICE_ATTR(in9_vbkp, S_IRUGO, madc_read, NULL, 9);
static SENSOR_DEVICE_ATTR(in10_battery_charger_current,
           S_IRUGO, madc_read, NULL, 10);
static SENSOR_DEVICE_ATTR(in11_battery_charger_voltage,
           S_IRUGO, madc_read, NULL, 11);
static SENSOR_DEVICE_ATTR(in12_main_battery_voltage,
           S_IRUGO, madc_read, NULL, 12);
static SENSOR_DEVICE_ATTR(in15_input, S_IRUGO, madc_read, NULL, 15);

static struct attribute *twl4030_madc_attributes[] = {
   &sensor_dev_attr_in0_battery_type.dev_attr.attr,
   &sensor_dev_attr_in1_battery_temp.dev_attr.attr,
   &sensor_dev_attr_in2_input.dev_attr.attr,
   &sensor_dev_attr_in3_input.dev_attr.attr,
   &sensor_dev_attr_in4_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_vbus.dev_attr.attr,
   &sensor_dev_attr_in9_vbkp.dev_attr.attr,
   &sensor_dev_attr_in10_battery_charger_current.dev_attr.attr,
   &sensor_dev_attr_in11_battery_charger_voltage.dev_attr.attr,
   &sensor_dev_attr_in12_main_battery_voltage.dev_attr.attr,
   &sensor_dev_attr_in15_input.dev_attr.attr,
   NULL
};

static const struct attribute_group twl4030_madc_group = {
   .attrs = twl4030_madc_attributes,
};

static int __devinit twl4030_madc_hwmon_probe(struct platform_device *pdev)
{
   int ret;
   int status;
   struct device *hwmon;

   ret = sysfs_create_group(&pdev->dev.kobj, &twl4030_madc_group);
   if (ret)
       goto err_sysfs;
   hwmon = hwmon_device_register(&pdev->dev);
   if (IS_ERR(hwmon)) {
       dev_err(&pdev->dev, "hwmon_device_register failed.\n");
       status = PTR_ERR(hwmon);
       goto err_reg;
   }

   return 0;

err_reg:
   sysfs_remove_group(&pdev->dev.kobj, &twl4030_madc_group);
err_sysfs:

   return ret;
}

static int __devexit twl4030_madc_hwmon_remove(struct platform_device *pdev)
{
   hwmon_device_unregister(&pdev->dev);
   sysfs_remove_group(&pdev->dev.kobj, &twl4030_madc_group);

   return 0;
}

static struct platform_driver twl4030_madc_hwmon_driver = {
   .probe = twl4030_madc_hwmon_probe,
   .remove = __exit_p(twl4030_madc_hwmon_remove),
   .driver = {
          .name = "twl4030_madc_hwmon",
          .owner = THIS_MODULE,
          },
};

static int __init twl4030_madc_hwmon_init(void)
{
   return platform_driver_register(&twl4030_madc_hwmon_driver);
}

module_init(twl4030_madc_hwmon_init);

static void __exit twl4030_madc_hwmon_exit(void)
{
   platform_driver_unregister(&twl4030_madc_hwmon_driver);
}

module_exit(twl4030_madc_hwmon_exit);

MODULE_DESCRIPTION("TWL4030 ADC Hwmon driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("J Keerthy");
MODULE_ALIAS("twl4030_madc_hwmon");