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twl4030-madc-hwmon.c
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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 <[email protected]>
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 {
47  struct twl4030_madc_request req = {
48  .channels = 1 << attr->index,
49  .method = TWL4030_MADC_SW2,
50  .type = TWL4030_MADC_WAIT,
51  };
52  long val;
53 
54  val = twl4030_madc_conversion(&req);
55  if (val < 0)
56  return val;
57 
58  return sprintf(buf, "%d\n", req.rbuf[attr->index]);
59 }
60 
61 /* sysfs nodes to read individual channels from user side */
62 static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, madc_read, NULL, 0);
63 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, madc_read, NULL, 1);
64 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, madc_read, NULL, 2);
65 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, madc_read, NULL, 3);
66 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, madc_read, NULL, 4);
67 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, madc_read, NULL, 5);
68 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, madc_read, NULL, 6);
69 static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, madc_read, NULL, 7);
70 static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, madc_read, NULL, 8);
71 static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, madc_read, NULL, 9);
72 static SENSOR_DEVICE_ATTR(curr10_input, S_IRUGO, madc_read, NULL, 10);
73 static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, madc_read, NULL, 11);
74 static SENSOR_DEVICE_ATTR(in12_input, S_IRUGO, madc_read, NULL, 12);
75 static SENSOR_DEVICE_ATTR(in15_input, S_IRUGO, madc_read, NULL, 15);
76 
77 static struct attribute *twl4030_madc_attributes[] = {
78  &sensor_dev_attr_in0_input.dev_attr.attr,
79  &sensor_dev_attr_temp1_input.dev_attr.attr,
80  &sensor_dev_attr_in2_input.dev_attr.attr,
81  &sensor_dev_attr_in3_input.dev_attr.attr,
82  &sensor_dev_attr_in4_input.dev_attr.attr,
83  &sensor_dev_attr_in5_input.dev_attr.attr,
84  &sensor_dev_attr_in6_input.dev_attr.attr,
85  &sensor_dev_attr_in7_input.dev_attr.attr,
86  &sensor_dev_attr_in8_input.dev_attr.attr,
87  &sensor_dev_attr_in9_input.dev_attr.attr,
88  &sensor_dev_attr_curr10_input.dev_attr.attr,
89  &sensor_dev_attr_in11_input.dev_attr.attr,
90  &sensor_dev_attr_in12_input.dev_attr.attr,
91  &sensor_dev_attr_in15_input.dev_attr.attr,
92  NULL
93 };
94 
95 static const struct attribute_group twl4030_madc_group = {
96  .attrs = twl4030_madc_attributes,
97 };
98 
99 static int __devinit twl4030_madc_hwmon_probe(struct platform_device *pdev)
100 {
101  int ret;
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  ret = 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 {
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 module_platform_driver(twl4030_madc_hwmon_driver);
141 
142 MODULE_DESCRIPTION("TWL4030 ADC Hwmon driver");
143 MODULE_LICENSE("GPL");
144 MODULE_AUTHOR("J Keerthy");
145 MODULE_ALIAS("platform:twl4030_madc_hwmon");