tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Driver for the ADC on Freescale Semiconductor MC13783 and MC13892 PMICs.
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/mc13xxx.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>
27#include <linux/slab.h>
28#include <linux/init.h>
29#include <linux/err.h>
30
31#define DRIVER_NAME "mc13783-adc"
32
33/* platform device id driver data */
34#define MC13783_ADC_16CHANS 1
35#define MC13783_ADC_BPDIV2 2
36
37struct mc13783_adc_priv {
38 struct mc13xxx *mc13xxx;
39 struct device *hwmon_dev;
40 char name[PLATFORM_NAME_SIZE];
41};
42
43static ssize_t mc13783_adc_show_name(struct device *dev, struct device_attribute
44 *devattr, char *buf)
45{
46 struct mc13783_adc_priv *priv = dev_get_drvdata(dev);
47
48 return sprintf(buf, "%s\n", priv->name);
49}
50
51static int mc13783_adc_read(struct device *dev,
52 struct device_attribute *devattr, unsigned int *val)
53{
54 struct mc13783_adc_priv *priv = dev_get_drvdata(dev);
55 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
56 unsigned int channel = attr->index;
57 unsigned int sample[4];
58 int ret;
59
60 ret = mc13xxx_adc_do_conversion(priv->mc13xxx,
61 MC13XXX_ADC_MODE_MULT_CHAN,
62 channel, 0, 0, sample);
63 if (ret)
64 return ret;
65
66 channel &= 0x7;
67
68 *val = (sample[channel % 4] >> (channel > 3 ? 14 : 2)) & 0x3ff;
69
70 return 0;
71}
72
73static ssize_t mc13783_adc_read_bp(struct device *dev,
74 struct device_attribute *devattr, char *buf)
75{
76 unsigned val;
77 struct platform_device *pdev = to_platform_device(dev);
78 kernel_ulong_t driver_data = platform_get_device_id(pdev)->driver_data;
79 int ret = mc13783_adc_read(dev, devattr, &val);
80
81 if (ret)
82 return ret;
83
84 if (driver_data & MC13783_ADC_BPDIV2)
85 val = DIV_ROUND_CLOSEST(val * 9, 2);
86 else
87 /*
88 * BP (channel 2) reports with offset 2.4V to the actual value
89 * to fit the input range of the ADC. unit = 2.25mV = 9/4 mV.
90 */
91 val = DIV_ROUND_CLOSEST(val * 9, 4) + 2400;
92
93 return sprintf(buf, "%u\n", val);
94}
95
96static ssize_t mc13783_adc_read_gp(struct device *dev,
97 struct device_attribute *devattr, char *buf)
98{
99 unsigned val;
100 int ret = mc13783_adc_read(dev, devattr, &val);
101
102 if (ret)
103 return ret;
104
105 /*
106 * input range is [0, 2.3V], val has 10 bits, so each bit
107 * is worth 9/4 mV.
108 */
109 val = DIV_ROUND_CLOSEST(val * 9, 4);
110
111 return sprintf(buf, "%u\n", val);
112}
113
114static DEVICE_ATTR(name, S_IRUGO, mc13783_adc_show_name, NULL);
115static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, mc13783_adc_read_bp, NULL, 2);
116static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, mc13783_adc_read_gp, NULL, 5);
117static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, mc13783_adc_read_gp, NULL, 6);
118static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, mc13783_adc_read_gp, NULL, 7);
119static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, mc13783_adc_read_gp, NULL, 8);
120static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, mc13783_adc_read_gp, NULL, 9);
121static SENSOR_DEVICE_ATTR(in10_input, S_IRUGO, mc13783_adc_read_gp, NULL, 10);
122static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, mc13783_adc_read_gp, NULL, 11);
123static SENSOR_DEVICE_ATTR(in12_input, S_IRUGO, mc13783_adc_read_gp, NULL, 12);
124static SENSOR_DEVICE_ATTR(in13_input, S_IRUGO, mc13783_adc_read_gp, NULL, 13);
125static SENSOR_DEVICE_ATTR(in14_input, S_IRUGO, mc13783_adc_read_gp, NULL, 14);
126static SENSOR_DEVICE_ATTR(in15_input, S_IRUGO, mc13783_adc_read_gp, NULL, 15);
127
128static struct attribute *mc13783_attr_base[] = {
129 &dev_attr_name.attr,
130 &sensor_dev_attr_in2_input.dev_attr.attr,
131 &sensor_dev_attr_in5_input.dev_attr.attr,
132 &sensor_dev_attr_in6_input.dev_attr.attr,
133 &sensor_dev_attr_in7_input.dev_attr.attr,
134 NULL
135};
136
137static const struct attribute_group mc13783_group_base = {
138 .attrs = mc13783_attr_base,
139};
140
141/* these are only used if MC13783_ADC_16CHANS is provided in driver data */
142static struct attribute *mc13783_attr_16chans[] = {
143 &sensor_dev_attr_in8_input.dev_attr.attr,
144 &sensor_dev_attr_in9_input.dev_attr.attr,
145 &sensor_dev_attr_in10_input.dev_attr.attr,
146 &sensor_dev_attr_in11_input.dev_attr.attr,
147 NULL
148};
149
150static const struct attribute_group mc13783_group_16chans = {
151 .attrs = mc13783_attr_16chans,
152};
153
154/* last four channels may be occupied by the touchscreen */
155static struct attribute *mc13783_attr_ts[] = {
156 &sensor_dev_attr_in12_input.dev_attr.attr,
157 &sensor_dev_attr_in13_input.dev_attr.attr,
158 &sensor_dev_attr_in14_input.dev_attr.attr,
159 &sensor_dev_attr_in15_input.dev_attr.attr,
160 NULL
161};
162
163static const struct attribute_group mc13783_group_ts = {
164 .attrs = mc13783_attr_ts,
165};
166
167static int mc13783_adc_use_touchscreen(struct platform_device *pdev)
168{
169 struct mc13783_adc_priv *priv = platform_get_drvdata(pdev);
170 unsigned flags = mc13xxx_get_flags(priv->mc13xxx);
171
172 return flags & MC13XXX_USE_TOUCHSCREEN;
173}
174
175static int __init mc13783_adc_probe(struct platform_device *pdev)
176{
177 struct mc13783_adc_priv *priv;
178 int ret;
179 const struct platform_device_id *id = platform_get_device_id(pdev);
180 char *dash;
181
182 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
183 if (!priv)
184 return -ENOMEM;
185
186 priv->mc13xxx = dev_get_drvdata(pdev->dev.parent);
187 snprintf(priv->name, ARRAY_SIZE(priv->name), "%s", id->name);
188 dash = strchr(priv->name, '-');
189 if (dash)
190 *dash = '\0';
191
192 platform_set_drvdata(pdev, priv);
193
194 /* Register sysfs hooks */
195 ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group_base);
196 if (ret)
197 return ret;
198
199 if (id->driver_data & MC13783_ADC_16CHANS) {
200 ret = sysfs_create_group(&pdev->dev.kobj,
201 &mc13783_group_16chans);
202 if (ret)
203 goto out_err_create_16chans;
204 }
205
206 if (!mc13783_adc_use_touchscreen(pdev)) {
207 ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group_ts);
208 if (ret)
209 goto out_err_create_ts;
210 }
211
212 priv->hwmon_dev = hwmon_device_register(&pdev->dev);
213 if (IS_ERR(priv->hwmon_dev)) {
214 ret = PTR_ERR(priv->hwmon_dev);
215 dev_err(&pdev->dev,
216 "hwmon_device_register failed with %d.\n", ret);
217 goto out_err_register;
218 }
219
220 return 0;
221
222out_err_register:
223
224 if (!mc13783_adc_use_touchscreen(pdev))
225 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts);
226out_err_create_ts:
227
228 if (id->driver_data & MC13783_ADC_16CHANS)
229 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_16chans);
230out_err_create_16chans:
231
232 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_base);
233 return ret;
234}
235
236static int mc13783_adc_remove(struct platform_device *pdev)
237{
238 struct mc13783_adc_priv *priv = platform_get_drvdata(pdev);
239 kernel_ulong_t driver_data = platform_get_device_id(pdev)->driver_data;
240
241 hwmon_device_unregister(priv->hwmon_dev);
242
243 if (!mc13783_adc_use_touchscreen(pdev))
244 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts);
245
246 if (driver_data & MC13783_ADC_16CHANS)
247 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_16chans);
248
249 sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_base);
250
251 return 0;
252}
253
254static const struct platform_device_id mc13783_adc_idtable[] = {
255 {
256 .name = "mc13783-adc",
257 .driver_data = MC13783_ADC_16CHANS,
258 }, {
259 .name = "mc13892-adc",
260 .driver_data = MC13783_ADC_BPDIV2,
261 }, {
262 /* sentinel */
263 }
264};
265MODULE_DEVICE_TABLE(platform, mc13783_adc_idtable);
266
267static struct platform_driver mc13783_adc_driver = {
268 .remove = mc13783_adc_remove,
269 .driver = {
270 .name = DRIVER_NAME,
271 },
272 .id_table = mc13783_adc_idtable,
273};
274
275module_platform_driver_probe(mc13783_adc_driver, mc13783_adc_probe);
276
277MODULE_DESCRIPTION("MC13783 ADC driver");
278MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
279MODULE_LICENSE("GPL");