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Luotao Fu93ee0a72009-12-09 20:35:58 +01001/*
2 * Driver for the Freescale Semiconductor MC13783 adc.
3 *
4 * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
5 * Copyright (C) 2009 Sascha Hauer, Pengutronix
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2
10 * of the License, or (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License along with
17 * this program; if not, write to the Free Software Foundation, Inc., 51
18 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#include <linux/mfd/mc13783-private.h>
22#include <linux/platform_device.h>
23#include <linux/hwmon-sysfs.h>
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/hwmon.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090027#include <linux/slab.h>
Luotao Fu93ee0a72009-12-09 20:35:58 +010028#include <linux/init.h>
29#include <linux/err.h>
30
31#define MC13783_ADC_NAME "mc13783-adc"
32
33struct mc13783_adc_priv {
34 struct mc13783 *mc13783;
35 struct device *hwmon_dev;
36};
37
38static ssize_t mc13783_adc_show_name(struct device *dev, struct device_attribute
39 *devattr, char *buf)
40{
41 return sprintf(buf, "mc13783_adc\n");
42}
43
44static int mc13783_adc_read(struct device *dev,
45 struct device_attribute *devattr, unsigned int *val)
46{
47 struct platform_device *pdev = to_platform_device(dev);
48 struct mc13783_adc_priv *priv = platform_get_drvdata(pdev);
49 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
50 unsigned int channel = attr->index;
51 unsigned int sample[4];
52 int ret;
53
54 ret = mc13783_adc_do_conversion(priv->mc13783,
55 MC13783_ADC_MODE_MULT_CHAN,
56 channel, sample);
57 if (ret)
58 return ret;
59
60 channel &= 0x7;
61
62 *val = (sample[channel % 4] >> (channel > 3 ? 14 : 2)) & 0x3ff;
63
64 return 0;
65}
66
67static ssize_t mc13783_adc_read_bp(struct device *dev,
68 struct device_attribute *devattr, char *buf)
69{
70 unsigned val;
71 int ret = mc13783_adc_read(dev, devattr, &val);
72
73 if (ret)
74 return ret;
75
76 /*
77 * BP (channel 2) reports with offset 2.4V to the actual value to fit
78 * the input range of the ADC. unit = 2.25mV = 9/4 mV.
79 */
80 val = DIV_ROUND_CLOSEST(val * 9, 4) + 2400;
81
82 return sprintf(buf, "%u\n", val);
83}
84
85static ssize_t mc13783_adc_read_gp(struct device *dev,
86 struct device_attribute *devattr, char *buf)
87{
88 unsigned val;
89 int ret = mc13783_adc_read(dev, devattr, &val);
90
91 if (ret)
92 return ret;
93
94 /*
95 * input range is [0, 2.3V], val has 10 bits, so each bit
96 * is worth 9/4 mV.
97 */
98 val = DIV_ROUND_CLOSEST(val * 9, 4);
99
100 return sprintf(buf, "%u\n", val);
101}
102
103static DEVICE_ATTR(name, S_IRUGO, mc13783_adc_show_name, NULL);
104static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, mc13783_adc_read_bp, NULL, 2);
105static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, mc13783_adc_read_gp, NULL, 5);
106static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, mc13783_adc_read_gp, NULL, 6);
107static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, mc13783_adc_read_gp, NULL, 7);
108static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, mc13783_adc_read_gp, NULL, 8);
109static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, mc13783_adc_read_gp, NULL, 9);
110static SENSOR_DEVICE_ATTR(in10_input, S_IRUGO, mc13783_adc_read_gp, NULL, 10);
111static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, mc13783_adc_read_gp, NULL, 11);
112static SENSOR_DEVICE_ATTR(in12_input, S_IRUGO, mc13783_adc_read_gp, NULL, 12);
113static SENSOR_DEVICE_ATTR(in13_input, S_IRUGO, mc13783_adc_read_gp, NULL, 13);
114static SENSOR_DEVICE_ATTR(in14_input, S_IRUGO, mc13783_adc_read_gp, NULL, 14);
115static SENSOR_DEVICE_ATTR(in15_input, S_IRUGO, mc13783_adc_read_gp, NULL, 15);
116
117static struct attribute *mc13783_attr[] = {
118 &dev_attr_name.attr,
119 &sensor_dev_attr_in2_input.dev_attr.attr,
120 &sensor_dev_attr_in5_input.dev_attr.attr,
121 &sensor_dev_attr_in6_input.dev_attr.attr,
122 &sensor_dev_attr_in7_input.dev_attr.attr,
123 &sensor_dev_attr_in8_input.dev_attr.attr,
124 &sensor_dev_attr_in9_input.dev_attr.attr,
125 &sensor_dev_attr_in10_input.dev_attr.attr,
126 &sensor_dev_attr_in11_input.dev_attr.attr,
127 NULL
128};
129
130static const struct attribute_group mc13783_group = {
131 .attrs = mc13783_attr,
132};
133
134/* last four channels may be occupied by the touchscreen */
135static struct attribute *mc13783_attr_ts[] = {
136 &sensor_dev_attr_in12_input.dev_attr.attr,
137 &sensor_dev_attr_in13_input.dev_attr.attr,
138 &sensor_dev_attr_in14_input.dev_attr.attr,
139 &sensor_dev_attr_in15_input.dev_attr.attr,
140 NULL
141};
142
143static const struct attribute_group mc13783_group_ts = {
144 .attrs = mc13783_attr_ts,
145};
146
147static int __init mc13783_adc_probe(struct platform_device *pdev)
148{
149 struct mc13783_adc_priv *priv;
150 int ret;
151
152 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
153 if (!priv)
154 return -ENOMEM;
155
156 priv->mc13783 = dev_get_drvdata(pdev->dev.parent);
157
158 platform_set_drvdata(pdev, priv);
159
160 /* Register sysfs hooks */
161 ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group);
162 if (ret)
163 goto out_err_create1;
164
165 if (!(priv->mc13783->flags & MC13783_USE_TOUCHSCREEN))
166 ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group_ts);
167 if (ret)
168 goto out_err_create2;
169
170 priv->hwmon_dev = hwmon_device_register(&pdev->dev);
171 if (IS_ERR(priv->hwmon_dev)) {
172 ret = PTR_ERR(priv->hwmon_dev);
173 dev_err(&pdev->dev,
174 "hwmon_device_register failed with %d.\n", ret);
175 goto out_err_register;
176 }
177
178
179 return 0;
180
181out_err_register:
182
183 if (!(priv->mc13783->flags & MC13783_USE_TOUCHSCREEN))
184 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts);
185out_err_create2:
186
187 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group);
188out_err_create1:
189
190 platform_set_drvdata(pdev, NULL);
191 kfree(priv);
192
193 return ret;
194}
195
196static int __devexit mc13783_adc_remove(struct platform_device *pdev)
197{
198 struct mc13783_adc_priv *priv = platform_get_drvdata(pdev);
199
200 hwmon_device_unregister(priv->hwmon_dev);
201
202 if (!(priv->mc13783->flags & MC13783_USE_TOUCHSCREEN))
203 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts);
204
205 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group);
206
207 platform_set_drvdata(pdev, NULL);
208 kfree(priv);
209
210 return 0;
211}
212
213static struct platform_driver mc13783_adc_driver = {
214 .remove = __devexit_p(mc13783_adc_remove),
215 .driver = {
216 .owner = THIS_MODULE,
217 .name = MC13783_ADC_NAME,
218 },
219};
220
221static int __init mc13783_adc_init(void)
222{
223 return platform_driver_probe(&mc13783_adc_driver, mc13783_adc_probe);
224}
225
226static void __exit mc13783_adc_exit(void)
227{
228 platform_driver_unregister(&mc13783_adc_driver);
229}
230
231module_init(mc13783_adc_init);
232module_exit(mc13783_adc_exit);
233
234MODULE_DESCRIPTION("MC13783 ADC driver");
235MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
236MODULE_LICENSE("GPL");
237MODULE_ALIAS("platform:" MC13783_ADC_NAME);