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Marc Pignatd42139a2008-08-15 00:40:34 -07001/*
2 * adcxx.c
3 *
4 * The adcxx4s is an AD converter family from National Semiconductor (NS).
5 *
6 * Copyright (c) 2008 Marc Pignat <marc.pignat@hevs.ch>
7 *
8 * The adcxx4s communicates with a host processor via an SPI/Microwire Bus
9 * interface. This driver supports the whole family of devices with name
10 * ADC<bb><c>S<sss>, where
11 * * bb is the resolution in number of bits (8, 10, 12)
12 * * c is the number of channels (1, 2, 4, 8)
13 * * sss is the maximum conversion speed (021 for 200 kSPS, 051 for 500 kSPS
14 * and 101 for 1 MSPS)
15 *
16 * Complete datasheets are available at National's website here:
17 * http://www.national.com/ds/DC/ADC<bb><c>S<sss>.pdf
18 *
19 * Handling of 8, 10 and 12 bits converters are the same, the
20 * unavailable bits are 0 :)
21 *
22 * This program is free software; you can redistribute it and/or modify
23 * it under the terms of the GNU General Public License as published by
24 * the Free Software Foundation; either version 2 of the License, or
25 * (at your option) any later version.
26 *
27 * This program is distributed in the hope that it will be useful,
28 * but WITHOUT ANY WARRANTY; without even the implied warranty of
29 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
30 * GNU General Public License for more details.
31 *
32 * You should have received a copy of the GNU General Public License
33 * along with this program; if not, write to the Free Software
34 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
35 */
36
37#include <linux/init.h>
38#include <linux/module.h>
39#include <linux/kernel.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090040#include <linux/slab.h>
Marc Pignatd42139a2008-08-15 00:40:34 -070041#include <linux/device.h>
42#include <linux/err.h>
43#include <linux/sysfs.h>
44#include <linux/hwmon.h>
45#include <linux/hwmon-sysfs.h>
46#include <linux/mutex.h>
Anton Vorontsovd2a5c102009-09-22 16:46:05 -070047#include <linux/mod_devicetable.h>
Marc Pignatd42139a2008-08-15 00:40:34 -070048#include <linux/spi/spi.h>
49
50#define DRVNAME "adcxx"
51
52struct adcxx {
53 struct device *hwmon_dev;
54 struct mutex lock;
55 u32 channels;
56 u32 reference; /* in millivolts */
57};
58
59/* sysfs hook function */
60static ssize_t adcxx_read(struct device *dev,
61 struct device_attribute *devattr, char *buf)
62{
63 struct spi_device *spi = to_spi_device(dev);
64 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
Jean Delvare95de3b22011-05-25 20:43:31 +020065 struct adcxx *adc = spi_get_drvdata(spi);
José Miguel Gonçalves57481502010-03-05 13:43:58 -080066 u8 tx_buf[2];
Marc Pignatd42139a2008-08-15 00:40:34 -070067 u8 rx_buf[2];
68 int status;
José Miguel Gonçalves57481502010-03-05 13:43:58 -080069 u32 value;
Marc Pignatd42139a2008-08-15 00:40:34 -070070
71 if (mutex_lock_interruptible(&adc->lock))
72 return -ERESTARTSYS;
73
José Miguel Gonçalves57481502010-03-05 13:43:58 -080074 if (adc->channels == 1) {
75 status = spi_read(spi, rx_buf, sizeof(rx_buf));
76 } else {
77 tx_buf[0] = attr->index << 3; /* other bits are don't care */
78 status = spi_write_then_read(spi, tx_buf, sizeof(tx_buf),
79 rx_buf, sizeof(rx_buf));
80 }
Marc Pignatd42139a2008-08-15 00:40:34 -070081 if (status < 0) {
José Miguel Gonçalves57481502010-03-05 13:43:58 -080082 dev_warn(dev, "SPI synch. transfer failed with status %d\n",
Marc Pignatd42139a2008-08-15 00:40:34 -070083 status);
84 goto out;
85 }
86
87 value = (rx_buf[0] << 8) + rx_buf[1];
88 dev_dbg(dev, "raw value = 0x%x\n", value);
89
90 value = value * adc->reference >> 12;
91 status = sprintf(buf, "%d\n", value);
92out:
93 mutex_unlock(&adc->lock);
94 return status;
95}
96
97static ssize_t adcxx_show_min(struct device *dev,
98 struct device_attribute *devattr, char *buf)
99{
100 /* The minimum reference is 0 for this chip family */
101 return sprintf(buf, "0\n");
102}
103
104static ssize_t adcxx_show_max(struct device *dev,
105 struct device_attribute *devattr, char *buf)
106{
107 struct spi_device *spi = to_spi_device(dev);
Jean Delvare95de3b22011-05-25 20:43:31 +0200108 struct adcxx *adc = spi_get_drvdata(spi);
Marc Pignatd42139a2008-08-15 00:40:34 -0700109 u32 reference;
110
111 if (mutex_lock_interruptible(&adc->lock))
112 return -ERESTARTSYS;
113
114 reference = adc->reference;
115
116 mutex_unlock(&adc->lock);
117
118 return sprintf(buf, "%d\n", reference);
119}
120
121static ssize_t adcxx_set_max(struct device *dev,
122 struct device_attribute *devattr, const char *buf, size_t count)
123{
124 struct spi_device *spi = to_spi_device(dev);
Jean Delvare95de3b22011-05-25 20:43:31 +0200125 struct adcxx *adc = spi_get_drvdata(spi);
Marc Pignatd42139a2008-08-15 00:40:34 -0700126 unsigned long value;
127
Frans Meulenbroeks179c4fd2012-01-04 20:58:52 +0100128 if (kstrtoul(buf, 10, &value))
Marc Pignatd42139a2008-08-15 00:40:34 -0700129 return -EINVAL;
130
131 if (mutex_lock_interruptible(&adc->lock))
132 return -ERESTARTSYS;
133
134 adc->reference = value;
135
136 mutex_unlock(&adc->lock);
137
138 return count;
139}
140
141static ssize_t adcxx_show_name(struct device *dev, struct device_attribute
142 *devattr, char *buf)
143{
144 struct spi_device *spi = to_spi_device(dev);
Jean Delvare95de3b22011-05-25 20:43:31 +0200145 struct adcxx *adc = spi_get_drvdata(spi);
Marc Pignatd42139a2008-08-15 00:40:34 -0700146
147 return sprintf(buf, "adcxx%ds\n", adc->channels);
148}
149
150static struct sensor_device_attribute ad_input[] = {
151 SENSOR_ATTR(name, S_IRUGO, adcxx_show_name, NULL, 0),
152 SENSOR_ATTR(in_min, S_IRUGO, adcxx_show_min, NULL, 0),
153 SENSOR_ATTR(in_max, S_IWUSR | S_IRUGO, adcxx_show_max,
154 adcxx_set_max, 0),
155 SENSOR_ATTR(in0_input, S_IRUGO, adcxx_read, NULL, 0),
156 SENSOR_ATTR(in1_input, S_IRUGO, adcxx_read, NULL, 1),
157 SENSOR_ATTR(in2_input, S_IRUGO, adcxx_read, NULL, 2),
158 SENSOR_ATTR(in3_input, S_IRUGO, adcxx_read, NULL, 3),
159 SENSOR_ATTR(in4_input, S_IRUGO, adcxx_read, NULL, 4),
160 SENSOR_ATTR(in5_input, S_IRUGO, adcxx_read, NULL, 5),
161 SENSOR_ATTR(in6_input, S_IRUGO, adcxx_read, NULL, 6),
162 SENSOR_ATTR(in7_input, S_IRUGO, adcxx_read, NULL, 7),
163};
164
165/*----------------------------------------------------------------------*/
166
Anton Vorontsovd2a5c102009-09-22 16:46:05 -0700167static int __devinit adcxx_probe(struct spi_device *spi)
Marc Pignatd42139a2008-08-15 00:40:34 -0700168{
Anton Vorontsovd2a5c102009-09-22 16:46:05 -0700169 int channels = spi_get_device_id(spi)->driver_data;
Marc Pignatd42139a2008-08-15 00:40:34 -0700170 struct adcxx *adc;
171 int status;
172 int i;
173
174 adc = kzalloc(sizeof *adc, GFP_KERNEL);
175 if (!adc)
176 return -ENOMEM;
177
178 /* set a default value for the reference */
179 adc->reference = 3300;
180 adc->channels = channels;
181 mutex_init(&adc->lock);
182
183 mutex_lock(&adc->lock);
184
Jean Delvare95de3b22011-05-25 20:43:31 +0200185 spi_set_drvdata(spi, adc);
Marc Pignatd42139a2008-08-15 00:40:34 -0700186
187 for (i = 0; i < 3 + adc->channels; i++) {
188 status = device_create_file(&spi->dev, &ad_input[i].dev_attr);
189 if (status) {
190 dev_err(&spi->dev, "device_create_file failed.\n");
191 goto out_err;
192 }
193 }
194
195 adc->hwmon_dev = hwmon_device_register(&spi->dev);
196 if (IS_ERR(adc->hwmon_dev)) {
197 dev_err(&spi->dev, "hwmon_device_register failed.\n");
198 status = PTR_ERR(adc->hwmon_dev);
199 goto out_err;
200 }
201
202 mutex_unlock(&adc->lock);
203 return 0;
204
205out_err:
206 for (i--; i >= 0; i--)
207 device_remove_file(&spi->dev, &ad_input[i].dev_attr);
208
Jean Delvare95de3b22011-05-25 20:43:31 +0200209 spi_set_drvdata(spi, NULL);
Marc Pignatd42139a2008-08-15 00:40:34 -0700210 mutex_unlock(&adc->lock);
211 kfree(adc);
212 return status;
213}
214
Marc Pignatd42139a2008-08-15 00:40:34 -0700215static int __devexit adcxx_remove(struct spi_device *spi)
216{
Jean Delvare95de3b22011-05-25 20:43:31 +0200217 struct adcxx *adc = spi_get_drvdata(spi);
Marc Pignatd42139a2008-08-15 00:40:34 -0700218 int i;
219
220 mutex_lock(&adc->lock);
221 hwmon_device_unregister(adc->hwmon_dev);
222 for (i = 0; i < 3 + adc->channels; i++)
223 device_remove_file(&spi->dev, &ad_input[i].dev_attr);
224
Jean Delvare95de3b22011-05-25 20:43:31 +0200225 spi_set_drvdata(spi, NULL);
Marc Pignatd42139a2008-08-15 00:40:34 -0700226 mutex_unlock(&adc->lock);
227 kfree(adc);
228
229 return 0;
230}
231
Anton Vorontsovd2a5c102009-09-22 16:46:05 -0700232static const struct spi_device_id adcxx_ids[] = {
233 { "adcxx1s", 1 },
234 { "adcxx2s", 2 },
235 { "adcxx4s", 4 },
236 { "adcxx8s", 8 },
237 { },
Marc Pignatd42139a2008-08-15 00:40:34 -0700238};
Anton Vorontsovd2a5c102009-09-22 16:46:05 -0700239MODULE_DEVICE_TABLE(spi, adcxx_ids);
Marc Pignatd42139a2008-08-15 00:40:34 -0700240
Anton Vorontsovd2a5c102009-09-22 16:46:05 -0700241static struct spi_driver adcxx_driver = {
Marc Pignatd42139a2008-08-15 00:40:34 -0700242 .driver = {
Anton Vorontsovd2a5c102009-09-22 16:46:05 -0700243 .name = "adcxx",
Marc Pignatd42139a2008-08-15 00:40:34 -0700244 .owner = THIS_MODULE,
245 },
Anton Vorontsovd2a5c102009-09-22 16:46:05 -0700246 .id_table = adcxx_ids,
247 .probe = adcxx_probe,
Marc Pignatd42139a2008-08-15 00:40:34 -0700248 .remove = __devexit_p(adcxx_remove),
249};
250
Axel Lin91efffe2012-01-20 15:53:47 +0800251module_spi_driver(adcxx_driver);
Marc Pignatd42139a2008-08-15 00:40:34 -0700252
253MODULE_AUTHOR("Marc Pignat");
254MODULE_DESCRIPTION("National Semiconductor adcxx8sxxx Linux driver");
255MODULE_LICENSE("GPL");