summaryrefslogtreecommitdiffstats
path: root/drivers/hwmon/mc13783-adc.c
blob: 2a7f331cd3c012a48652fffed43c458482ec2f89 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
/*
 * Driver for the ADC on Freescale Semiconductor MC13783 and MC13892 PMICs.
 *
 * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
 * Copyright (C) 2009 Sascha Hauer, Pengutronix
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 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/mfd/mc13xxx.h>
#include <linux/platform_device.h>
#include <linux/hwmon-sysfs.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/hwmon.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/err.h>

#define DRIVER_NAME	"mc13783-adc"

/* platform device id driver data */
#define MC13783_ADC_16CHANS	1
#define MC13783_ADC_BPDIV2	2

struct mc13783_adc_priv {
	struct mc13xxx *mc13xxx;
	struct device *hwmon_dev;
	char name[10];
};

static ssize_t mc13783_adc_show_name(struct device *dev, struct device_attribute
			      *devattr, char *buf)
{
	struct mc13783_adc_priv *priv = dev_get_drvdata(dev);

	return sprintf(buf, "%s\n", priv->name);
}

static int mc13783_adc_read(struct device *dev,
		struct device_attribute *devattr, unsigned int *val)
{
	struct mc13783_adc_priv *priv = dev_get_drvdata(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	unsigned int channel = attr->index;
	unsigned int sample[4];
	int ret;

	ret = mc13xxx_adc_do_conversion(priv->mc13xxx,
			MC13XXX_ADC_MODE_MULT_CHAN,
			channel, 0, 0, sample);
	if (ret)
		return ret;

	channel &= 0x7;

	*val = (sample[channel % 4] >> (channel > 3 ? 14 : 2)) & 0x3ff;

	return 0;
}

static ssize_t mc13783_adc_read_bp(struct device *dev,
		struct device_attribute *devattr, char *buf)
{
	unsigned val;
	struct platform_device *pdev = to_platform_device(dev);
	kernel_ulong_t driver_data = platform_get_device_id(pdev)->driver_data;
	int ret = mc13783_adc_read(dev, devattr, &val);

	if (ret)
		return ret;

	if (driver_data & MC13783_ADC_BPDIV2)
		val = DIV_ROUND_CLOSEST(val * 9, 2);
	else
		/*
		 * BP (channel 2) reports with offset 2.4V to the actual value
		 * to fit the input range of the ADC.  unit = 2.25mV = 9/4 mV.
		 */
		val = DIV_ROUND_CLOSEST(val * 9, 4) + 2400;

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

static ssize_t mc13783_adc_read_gp(struct device *dev,
		struct device_attribute *devattr, char *buf)
{
	unsigned val;
	int ret = mc13783_adc_read(dev, devattr, &val);

	if (ret)
		return ret;

	/*
	 * input range is [0, 2.3V], val has 10 bits, so each bit
	 * is worth 9/4 mV.
	 */
	val = DIV_ROUND_CLOSEST(val * 9, 4);

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

static DEVICE_ATTR(name, S_IRUGO, mc13783_adc_show_name, NULL);
static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, mc13783_adc_read_bp, NULL, 2);
static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, mc13783_adc_read_gp, NULL, 5);
static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, mc13783_adc_read_gp, NULL, 6);
static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, mc13783_adc_read_gp, NULL, 7);
static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, mc13783_adc_read_gp, NULL, 8);
static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, mc13783_adc_read_gp, NULL, 9);
static SENSOR_DEVICE_ATTR(in10_input, S_IRUGO, mc13783_adc_read_gp, NULL, 10);
static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, mc13783_adc_read_gp, NULL, 11);
static SENSOR_DEVICE_ATTR(in12_input, S_IRUGO, mc13783_adc_read_gp, NULL, 12);
static SENSOR_DEVICE_ATTR(in13_input, S_IRUGO, mc13783_adc_read_gp, NULL, 13);
static SENSOR_DEVICE_ATTR(in14_input, S_IRUGO, mc13783_adc_read_gp, NULL, 14);
static SENSOR_DEVICE_ATTR(in15_input, S_IRUGO, mc13783_adc_read_gp, NULL, 15);

static struct attribute *mc13783_attr_base[] = {
	&dev_attr_name.attr,
	&sensor_dev_attr_in2_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,
	NULL
};

static const struct attribute_group mc13783_group_base = {
	.attrs = mc13783_attr_base,
};

/* these are only used if MC13783_ADC_16CHANS is provided in driver data */
static struct attribute *mc13783_attr_16chans[] = {
	&sensor_dev_attr_in8_input.dev_attr.attr,
	&sensor_dev_attr_in9_input.dev_attr.attr,
	&sensor_dev_attr_in10_input.dev_attr.attr,
	&sensor_dev_attr_in11_input.dev_attr.attr,
	NULL
};

static const struct attribute_group mc13783_group_16chans = {
	.attrs = mc13783_attr_16chans,
};

/* last four channels may be occupied by the touchscreen */
static struct attribute *mc13783_attr_ts[] = {
	&sensor_dev_attr_in12_input.dev_attr.attr,
	&sensor_dev_attr_in13_input.dev_attr.attr,
	&sensor_dev_attr_in14_input.dev_attr.attr,
	&sensor_dev_attr_in15_input.dev_attr.attr,
	NULL
};

static const struct attribute_group mc13783_group_ts = {
	.attrs = mc13783_attr_ts,
};

static int mc13783_adc_use_touchscreen(struct platform_device *pdev)
{
	struct mc13783_adc_priv *priv = platform_get_drvdata(pdev);
	unsigned flags = mc13xxx_get_flags(priv->mc13xxx);

	return flags & MC13XXX_USE_TOUCHSCREEN;
}

static int __init mc13783_adc_probe(struct platform_device *pdev)
{
	struct mc13783_adc_priv *priv;
	int ret;
	const struct platform_device_id *id = platform_get_device_id(pdev);
	char *dash;

	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	priv->mc13xxx = dev_get_drvdata(pdev->dev.parent);
	snprintf(priv->name, ARRAY_SIZE(priv->name), "%s", id->name);
	dash = strchr(priv->name, '-');
	if (dash)
		*dash = '\0';

	platform_set_drvdata(pdev, priv);

	/* Register sysfs hooks */
	ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group_base);
	if (ret)
		return ret;

	if (id->driver_data & MC13783_ADC_16CHANS) {
		ret = sysfs_create_group(&pdev->dev.kobj,
				&mc13783_group_16chans);
		if (ret)
			goto out_err_create_16chans;
	}

	if (!mc13783_adc_use_touchscreen(pdev)) {
		ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group_ts);
		if (ret)
			goto out_err_create_ts;
	}

	priv->hwmon_dev = hwmon_device_register(&pdev->dev);
	if (IS_ERR(priv->hwmon_dev)) {
		ret = PTR_ERR(priv->hwmon_dev);
		dev_err(&pdev->dev,
				"hwmon_device_register failed with %d.\n", ret);
		goto out_err_register;
	}

	return 0;

out_err_register:

	if (!mc13783_adc_use_touchscreen(pdev))
		sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts);
out_err_create_ts:

	if (id->driver_data & MC13783_ADC_16CHANS)
		sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_16chans);
out_err_create_16chans:

	sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_base);
	return ret;
}

static int mc13783_adc_remove(struct platform_device *pdev)
{
	struct mc13783_adc_priv *priv = platform_get_drvdata(pdev);
	kernel_ulong_t driver_data = platform_get_device_id(pdev)->driver_data;

	hwmon_device_unregister(priv->hwmon_dev);

	if (!mc13783_adc_use_touchscreen(pdev))
		sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts);

	if (driver_data & MC13783_ADC_16CHANS)
		sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_16chans);

	sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_base);

	return 0;
}

static const struct platform_device_id mc13783_adc_idtable[] = {
	{
		.name = "mc13783-adc",
		.driver_data = MC13783_ADC_16CHANS,
	}, {
		.name = "mc13892-adc",
		.driver_data = MC13783_ADC_BPDIV2,
	}, {
		/* sentinel */
	}
};
MODULE_DEVICE_TABLE(platform, mc13783_adc_idtable);

static struct platform_driver mc13783_adc_driver = {
	.remove		= mc13783_adc_remove,
	.driver		= {
		.owner	= THIS_MODULE,
		.name	= DRIVER_NAME,
	},
	.id_table	= mc13783_adc_idtable,
};

static int __init mc13783_adc_init(void)
{
	return platform_driver_probe(&mc13783_adc_driver, mc13783_adc_probe);
}

static void __exit mc13783_adc_exit(void)
{
	platform_driver_unregister(&mc13783_adc_driver);
}

module_init(mc13783_adc_init);
module_exit(mc13783_adc_exit);

MODULE_DESCRIPTION("MC13783 ADC driver");
MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
MODULE_LICENSE("GPL");
OpenPOWER on IntegriCloud