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d42139a3 MP |
1 | /* |
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> | |
5a0e3ad6 | 40 | #include <linux/slab.h> |
d42139a3 MP |
41 | #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> | |
d2a5c10f | 47 | #include <linux/mod_devicetable.h> |
d42139a3 MP |
48 | #include <linux/spi/spi.h> |
49 | ||
50 | #define DRVNAME "adcxx" | |
51 | ||
52 | struct adcxx { | |
53 | struct device *hwmon_dev; | |
54 | struct mutex lock; | |
55 | u32 channels; | |
56 | u32 reference; /* in millivolts */ | |
57 | }; | |
58 | ||
59 | /* sysfs hook function */ | |
60 | static 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); | |
95de3b25 | 65 | struct adcxx *adc = spi_get_drvdata(spi); |
5748150e | 66 | u8 tx_buf[2]; |
d42139a3 MP |
67 | u8 rx_buf[2]; |
68 | int status; | |
5748150e | 69 | u32 value; |
d42139a3 MP |
70 | |
71 | if (mutex_lock_interruptible(&adc->lock)) | |
72 | return -ERESTARTSYS; | |
73 | ||
5748150e JMG |
74 | 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 | } | |
d42139a3 | 81 | if (status < 0) { |
5748150e | 82 | dev_warn(dev, "SPI synch. transfer failed with status %d\n", |
d42139a3 MP |
83 | 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); | |
92 | out: | |
93 | mutex_unlock(&adc->lock); | |
94 | return status; | |
95 | } | |
96 | ||
97 | static 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 | ||
104 | static 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); | |
95de3b25 | 108 | struct adcxx *adc = spi_get_drvdata(spi); |
d42139a3 MP |
109 | 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 | ||
121 | static 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); | |
95de3b25 | 125 | struct adcxx *adc = spi_get_drvdata(spi); |
d42139a3 MP |
126 | unsigned long value; |
127 | ||
128 | if (strict_strtoul(buf, 10, &value)) | |
129 | 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 | ||
141 | static 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); | |
95de3b25 | 145 | struct adcxx *adc = spi_get_drvdata(spi); |
d42139a3 MP |
146 | |
147 | return sprintf(buf, "adcxx%ds\n", adc->channels); | |
148 | } | |
149 | ||
150 | static 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 | ||
d2a5c10f | 167 | static int __devinit adcxx_probe(struct spi_device *spi) |
d42139a3 | 168 | { |
d2a5c10f | 169 | int channels = spi_get_device_id(spi)->driver_data; |
d42139a3 MP |
170 | 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 | ||
95de3b25 | 185 | spi_set_drvdata(spi, adc); |
d42139a3 MP |
186 | |
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 | ||
205 | out_err: | |
206 | for (i--; i >= 0; i--) | |
207 | device_remove_file(&spi->dev, &ad_input[i].dev_attr); | |
208 | ||
95de3b25 | 209 | spi_set_drvdata(spi, NULL); |
d42139a3 MP |
210 | mutex_unlock(&adc->lock); |
211 | kfree(adc); | |
212 | return status; | |
213 | } | |
214 | ||
d42139a3 MP |
215 | static int __devexit adcxx_remove(struct spi_device *spi) |
216 | { | |
95de3b25 | 217 | struct adcxx *adc = spi_get_drvdata(spi); |
d42139a3 MP |
218 | 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 | ||
95de3b25 | 225 | spi_set_drvdata(spi, NULL); |
d42139a3 MP |
226 | mutex_unlock(&adc->lock); |
227 | kfree(adc); | |
228 | ||
229 | return 0; | |
230 | } | |
231 | ||
d2a5c10f AV |
232 | static const struct spi_device_id adcxx_ids[] = { |
233 | { "adcxx1s", 1 }, | |
234 | { "adcxx2s", 2 }, | |
235 | { "adcxx4s", 4 }, | |
236 | { "adcxx8s", 8 }, | |
237 | { }, | |
d42139a3 | 238 | }; |
d2a5c10f | 239 | MODULE_DEVICE_TABLE(spi, adcxx_ids); |
d42139a3 | 240 | |
d2a5c10f | 241 | static struct spi_driver adcxx_driver = { |
d42139a3 | 242 | .driver = { |
d2a5c10f | 243 | .name = "adcxx", |
d42139a3 MP |
244 | .owner = THIS_MODULE, |
245 | }, | |
d2a5c10f AV |
246 | .id_table = adcxx_ids, |
247 | .probe = adcxx_probe, | |
d42139a3 MP |
248 | .remove = __devexit_p(adcxx_remove), |
249 | }; | |
250 | ||
251 | static int __init init_adcxx(void) | |
252 | { | |
d2a5c10f | 253 | return spi_register_driver(&adcxx_driver); |
d42139a3 MP |
254 | } |
255 | ||
256 | static void __exit exit_adcxx(void) | |
257 | { | |
d2a5c10f | 258 | spi_unregister_driver(&adcxx_driver); |
d42139a3 MP |
259 | } |
260 | ||
261 | module_init(init_adcxx); | |
262 | module_exit(exit_adcxx); | |
263 | ||
264 | MODULE_AUTHOR("Marc Pignat"); | |
265 | MODULE_DESCRIPTION("National Semiconductor adcxx8sxxx Linux driver"); | |
266 | MODULE_LICENSE("GPL"); |