drivers/hwmon/twl4030-madc-hwmon.c

   1 /*
   2  *
   3  * TWL4030 MADC Hwmon driver-This driver monitors the real time
   4  * conversion of analog signals like battery temperature,
   5  * battery type, battery level etc. User can ask for the conversion on a
   6  * particular channel using the sysfs nodes.
   7  *
   8  * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
   9  * J Keerthy <j-keerthy@ti.com>
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * version 2 as published by the Free Software Foundation.
  14  *
  15  * This program is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  23  * 02110-1301 USA
  24  *
  25  */
  26 #include <linux/init.h>
  27 #include <linux/module.h>
  28 #include <linux/kernel.h>
  29 #include <linux/i2c/twl.h>
  30 #include <linux/device.h>
  31 #include <linux/platform_device.h>
  32 #include <linux/i2c/twl4030-madc.h>
  33 #include <linux/hwmon.h>
  34 #include <linux/hwmon-sysfs.h>
  35 #include <linux/stddef.h>
  36 #include <linux/sysfs.h>
  37 #include <linux/err.h>
  38 #include <linux/types.h>
  39
  40 /*
  41  * sysfs hook function
  42  */
  43 static ssize_t madc_read(struct device *dev,
  44                          struct device_attribute *devattr, char *buf)
  45 {
  46         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  47         struct twl4030_madc_request req;
  48         long val;
  49
  50         req.channels = (1 << attr->index);
  51         req.method = TWL4030_MADC_SW2;
  52         req.func_cb = NULL;
  53         val = twl4030_madc_conversion(&req);
  54         if (val < 0)
  55                 return val;
  56
  57         return sprintf(buf, "%d\n", req.rbuf[attr->index]);
  58 }
  59
  60 /* sysfs nodes to read individual channels from user side */
  61 static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, madc_read, NULL, 0);
  62 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, madc_read, NULL, 1);
  63 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, madc_read, NULL, 2);
  64 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, madc_read, NULL, 3);
  65 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, madc_read, NULL, 4);
  66 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, madc_read, NULL, 5);
  67 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, madc_read, NULL, 6);
  68 static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, madc_read, NULL, 7);
  69 static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, madc_read, NULL, 8);
  70 static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, madc_read, NULL, 9);
  71 static SENSOR_DEVICE_ATTR(curr10_input, S_IRUGO, madc_read, NULL, 10);
  72 static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, madc_read, NULL, 11);
  73 static SENSOR_DEVICE_ATTR(in12_input, S_IRUGO, madc_read, NULL, 12);
  74 static SENSOR_DEVICE_ATTR(in15_input, S_IRUGO, madc_read, NULL, 15);
  75
  76 static struct attribute *twl4030_madc_attributes[] = {
  77         &sensor_dev_attr_in0_input.dev_attr.attr,
  78         &sensor_dev_attr_temp1_input.dev_attr.attr,
  79         &sensor_dev_attr_in2_input.dev_attr.attr,
  80         &sensor_dev_attr_in3_input.dev_attr.attr,
  81         &sensor_dev_attr_in4_input.dev_attr.attr,
  82         &sensor_dev_attr_in5_input.dev_attr.attr,
  83         &sensor_dev_attr_in6_input.dev_attr.attr,
  84         &sensor_dev_attr_in7_input.dev_attr.attr,
  85         &sensor_dev_attr_in8_input.dev_attr.attr,
  86         &sensor_dev_attr_in9_input.dev_attr.attr,
  87         &sensor_dev_attr_curr10_input.dev_attr.attr,
  88         &sensor_dev_attr_in11_input.dev_attr.attr,
  89         &sensor_dev_attr_in12_input.dev_attr.attr,
  90         &sensor_dev_attr_in15_input.dev_attr.attr,
  91         NULL
  92 };
  93
  94 static const struct attribute_group twl4030_madc_group = {
  95         .attrs = twl4030_madc_attributes,
  96 };
  97
  98 static int __devinit twl4030_madc_hwmon_probe(struct platform_device *pdev)
  99 {
 100         int ret;
 101         int status;
 102         struct device *hwmon;
 103
 104         ret = sysfs_create_group(&pdev->dev.kobj, &twl4030_madc_group);
 105         if (ret)
 106                 goto err_sysfs;
 107         hwmon = hwmon_device_register(&pdev->dev);
 108         if (IS_ERR(hwmon)) {
 109                 dev_err(&pdev->dev, "hwmon_device_register failed.\n");
 110                 status = PTR_ERR(hwmon);
 111                 goto err_reg;
 112         }
 113
 114         return 0;
 115
 116 err_reg:
 117         sysfs_remove_group(&pdev->dev.kobj, &twl4030_madc_group);
 118 err_sysfs:
 119
 120         return ret;
 121 }
 122
 123 static int __devexit twl4030_madc_hwmon_remove(struct platform_device *pdev)
 124 {
 125         hwmon_device_unregister(&pdev->dev);
 126         sysfs_remove_group(&pdev->dev.kobj, &twl4030_madc_group);
 127
 128         return 0;
 129 }
 130
 131 static struct platform_driver twl4030_madc_hwmon_driver = {
 132         .probe = twl4030_madc_hwmon_probe,
 133         .remove = __exit_p(twl4030_madc_hwmon_remove),
 134         .driver = {
 135                    .name = "twl4030_madc_hwmon",
 136                    .owner = THIS_MODULE,
 137                    },
 138 };
 139
 140 static int __init twl4030_madc_hwmon_init(void)
 141 {
 142         return platform_driver_register(&twl4030_madc_hwmon_driver);
 143 }
 144
 145 module_init(twl4030_madc_hwmon_init);
 146
 147 static void __exit twl4030_madc_hwmon_exit(void)
 148 {
 149         platform_driver_unregister(&twl4030_madc_hwmon_driver);
 150 }
 151
 152 module_exit(twl4030_madc_hwmon_exit);
 153
 154 MODULE_DESCRIPTION("TWL4030 ADC Hwmon driver");
 155 MODULE_LICENSE("GPL");
 156 MODULE_AUTHOR("J Keerthy");
 157 MODULE_ALIAS("platform:twl4030_madc_hwmon");