174ba9207SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later
2d42139a3SMarc Pignat /*
3d42139a3SMarc Pignat * adcxx.c
4d42139a3SMarc Pignat *
5d42139a3SMarc Pignat * The adcxx4s is an AD converter family from National Semiconductor (NS).
6d42139a3SMarc Pignat *
7d42139a3SMarc Pignat * Copyright (c) 2008 Marc Pignat <marc.pignat@hevs.ch>
8d42139a3SMarc Pignat *
9d42139a3SMarc Pignat * The adcxx4s communicates with a host processor via an SPI/Microwire Bus
10d42139a3SMarc Pignat * interface. This driver supports the whole family of devices with name
11d42139a3SMarc Pignat * ADC<bb><c>S<sss>, where
12d42139a3SMarc Pignat * * bb is the resolution in number of bits (8, 10, 12)
13d42139a3SMarc Pignat * * c is the number of channels (1, 2, 4, 8)
14d42139a3SMarc Pignat * * sss is the maximum conversion speed (021 for 200 kSPS, 051 for 500 kSPS
15d42139a3SMarc Pignat * and 101 for 1 MSPS)
16d42139a3SMarc Pignat *
17d42139a3SMarc Pignat * Complete datasheets are available at National's website here:
18d42139a3SMarc Pignat * http://www.national.com/ds/DC/ADC<bb><c>S<sss>.pdf
19d42139a3SMarc Pignat *
20d42139a3SMarc Pignat * Handling of 8, 10 and 12 bits converters are the same, the
21d42139a3SMarc Pignat * unavailable bits are 0 :)
22d42139a3SMarc Pignat */
23d42139a3SMarc Pignat
24d42139a3SMarc Pignat #include <linux/init.h>
25d42139a3SMarc Pignat #include <linux/module.h>
26d42139a3SMarc Pignat #include <linux/kernel.h>
275a0e3ad6STejun Heo #include <linux/slab.h>
28d42139a3SMarc Pignat #include <linux/device.h>
29d42139a3SMarc Pignat #include <linux/err.h>
30d42139a3SMarc Pignat #include <linux/sysfs.h>
31d42139a3SMarc Pignat #include <linux/hwmon.h>
32d42139a3SMarc Pignat #include <linux/hwmon-sysfs.h>
33d42139a3SMarc Pignat #include <linux/mutex.h>
34d2a5c10fSAnton Vorontsov #include <linux/mod_devicetable.h>
35d42139a3SMarc Pignat #include <linux/spi/spi.h>
36d42139a3SMarc Pignat
37d42139a3SMarc Pignat #define DRVNAME "adcxx"
38d42139a3SMarc Pignat
39d42139a3SMarc Pignat struct adcxx {
40d42139a3SMarc Pignat struct device *hwmon_dev;
41d42139a3SMarc Pignat struct mutex lock;
42d42139a3SMarc Pignat u32 channels;
43d42139a3SMarc Pignat u32 reference; /* in millivolts */
44d42139a3SMarc Pignat };
45d42139a3SMarc Pignat
46d42139a3SMarc Pignat /* sysfs hook function */
adcxx_show(struct device * dev,struct device_attribute * devattr,char * buf)47b0c130fdSGuenter Roeck static ssize_t adcxx_show(struct device *dev,
48d42139a3SMarc Pignat struct device_attribute *devattr, char *buf)
49d42139a3SMarc Pignat {
50d42139a3SMarc Pignat struct spi_device *spi = to_spi_device(dev);
51d42139a3SMarc Pignat struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
5295de3b25SJean Delvare struct adcxx *adc = spi_get_drvdata(spi);
535748150eSJosé Miguel Gonçalves u8 tx_buf[2];
54d42139a3SMarc Pignat u8 rx_buf[2];
55d42139a3SMarc Pignat int status;
565748150eSJosé Miguel Gonçalves u32 value;
57d42139a3SMarc Pignat
58d42139a3SMarc Pignat if (mutex_lock_interruptible(&adc->lock))
59d42139a3SMarc Pignat return -ERESTARTSYS;
60d42139a3SMarc Pignat
615748150eSJosé Miguel Gonçalves if (adc->channels == 1) {
625748150eSJosé Miguel Gonçalves status = spi_read(spi, rx_buf, sizeof(rx_buf));
635748150eSJosé Miguel Gonçalves } else {
645748150eSJosé Miguel Gonçalves tx_buf[0] = attr->index << 3; /* other bits are don't care */
65d42139a3SMarc Pignat status = spi_write_then_read(spi, tx_buf, sizeof(tx_buf),
66d42139a3SMarc Pignat rx_buf, sizeof(rx_buf));
675748150eSJosé Miguel Gonçalves }
68d42139a3SMarc Pignat if (status < 0) {
695748150eSJosé Miguel Gonçalves dev_warn(dev, "SPI synch. transfer failed with status %d\n",
70d42139a3SMarc Pignat status);
71d42139a3SMarc Pignat goto out;
72d42139a3SMarc Pignat }
73d42139a3SMarc Pignat
74d42139a3SMarc Pignat value = (rx_buf[0] << 8) + rx_buf[1];
75d42139a3SMarc Pignat dev_dbg(dev, "raw value = 0x%x\n", value);
76d42139a3SMarc Pignat
77d42139a3SMarc Pignat value = value * adc->reference >> 12;
78d42139a3SMarc Pignat status = sprintf(buf, "%d\n", value);
79d42139a3SMarc Pignat out:
80d42139a3SMarc Pignat mutex_unlock(&adc->lock);
81d42139a3SMarc Pignat return status;
82d42139a3SMarc Pignat }
83d42139a3SMarc Pignat
adcxx_min_show(struct device * dev,struct device_attribute * devattr,char * buf)84b0c130fdSGuenter Roeck static ssize_t adcxx_min_show(struct device *dev,
85d42139a3SMarc Pignat struct device_attribute *devattr, char *buf)
86d42139a3SMarc Pignat {
87d42139a3SMarc Pignat /* The minimum reference is 0 for this chip family */
88d42139a3SMarc Pignat return sprintf(buf, "0\n");
89d42139a3SMarc Pignat }
90d42139a3SMarc Pignat
adcxx_max_show(struct device * dev,struct device_attribute * devattr,char * buf)91b0c130fdSGuenter Roeck static ssize_t adcxx_max_show(struct device *dev,
92d42139a3SMarc Pignat struct device_attribute *devattr, char *buf)
93d42139a3SMarc Pignat {
94d42139a3SMarc Pignat struct spi_device *spi = to_spi_device(dev);
9595de3b25SJean Delvare struct adcxx *adc = spi_get_drvdata(spi);
96d42139a3SMarc Pignat u32 reference;
97d42139a3SMarc Pignat
98d42139a3SMarc Pignat if (mutex_lock_interruptible(&adc->lock))
99d42139a3SMarc Pignat return -ERESTARTSYS;
100d42139a3SMarc Pignat
101d42139a3SMarc Pignat reference = adc->reference;
102d42139a3SMarc Pignat
103d42139a3SMarc Pignat mutex_unlock(&adc->lock);
104d42139a3SMarc Pignat
105d42139a3SMarc Pignat return sprintf(buf, "%d\n", reference);
106d42139a3SMarc Pignat }
107d42139a3SMarc Pignat
adcxx_max_store(struct device * dev,struct device_attribute * devattr,const char * buf,size_t count)108b0c130fdSGuenter Roeck static ssize_t adcxx_max_store(struct device *dev,
109b0c130fdSGuenter Roeck struct device_attribute *devattr,
110b0c130fdSGuenter Roeck const char *buf, size_t count)
111d42139a3SMarc Pignat {
112d42139a3SMarc Pignat struct spi_device *spi = to_spi_device(dev);
11395de3b25SJean Delvare struct adcxx *adc = spi_get_drvdata(spi);
114d42139a3SMarc Pignat unsigned long value;
115d42139a3SMarc Pignat
116179c4fdbSFrans Meulenbroeks if (kstrtoul(buf, 10, &value))
117d42139a3SMarc Pignat return -EINVAL;
118d42139a3SMarc Pignat
119d42139a3SMarc Pignat if (mutex_lock_interruptible(&adc->lock))
120d42139a3SMarc Pignat return -ERESTARTSYS;
121d42139a3SMarc Pignat
122d42139a3SMarc Pignat adc->reference = value;
123d42139a3SMarc Pignat
124d42139a3SMarc Pignat mutex_unlock(&adc->lock);
125d42139a3SMarc Pignat
126d42139a3SMarc Pignat return count;
127d42139a3SMarc Pignat }
128d42139a3SMarc Pignat
adcxx_name_show(struct device * dev,struct device_attribute * devattr,char * buf)129b0c130fdSGuenter Roeck static ssize_t adcxx_name_show(struct device *dev,
130b0c130fdSGuenter Roeck struct device_attribute *devattr, char *buf)
131d42139a3SMarc Pignat {
132cc00e4ddSGuenter Roeck return sprintf(buf, "%s\n", to_spi_device(dev)->modalias);
133d42139a3SMarc Pignat }
134d42139a3SMarc Pignat
135d42139a3SMarc Pignat static struct sensor_device_attribute ad_input[] = {
136b0c130fdSGuenter Roeck SENSOR_ATTR_RO(name, adcxx_name, 0),
137b0c130fdSGuenter Roeck SENSOR_ATTR_RO(in_min, adcxx_min, 0),
138b0c130fdSGuenter Roeck SENSOR_ATTR_RW(in_max, adcxx_max, 0),
139b0c130fdSGuenter Roeck SENSOR_ATTR_RO(in0_input, adcxx, 0),
140b0c130fdSGuenter Roeck SENSOR_ATTR_RO(in1_input, adcxx, 1),
141b0c130fdSGuenter Roeck SENSOR_ATTR_RO(in2_input, adcxx, 2),
142b0c130fdSGuenter Roeck SENSOR_ATTR_RO(in3_input, adcxx, 3),
143b0c130fdSGuenter Roeck SENSOR_ATTR_RO(in4_input, adcxx, 4),
144b0c130fdSGuenter Roeck SENSOR_ATTR_RO(in5_input, adcxx, 5),
145b0c130fdSGuenter Roeck SENSOR_ATTR_RO(in6_input, adcxx, 6),
146b0c130fdSGuenter Roeck SENSOR_ATTR_RO(in7_input, adcxx, 7),
147d42139a3SMarc Pignat };
148d42139a3SMarc Pignat
149d42139a3SMarc Pignat /*----------------------------------------------------------------------*/
150d42139a3SMarc Pignat
adcxx_probe(struct spi_device * spi)1516c931ae1SBill Pemberton static int adcxx_probe(struct spi_device *spi)
152d42139a3SMarc Pignat {
153d2a5c10fSAnton Vorontsov int channels = spi_get_device_id(spi)->driver_data;
154d42139a3SMarc Pignat struct adcxx *adc;
155d42139a3SMarc Pignat int status;
156d42139a3SMarc Pignat int i;
157d42139a3SMarc Pignat
158c60da825SGuenter Roeck adc = devm_kzalloc(&spi->dev, sizeof(*adc), GFP_KERNEL);
159d42139a3SMarc Pignat if (!adc)
160d42139a3SMarc Pignat return -ENOMEM;
161d42139a3SMarc Pignat
162d42139a3SMarc Pignat /* set a default value for the reference */
163d42139a3SMarc Pignat adc->reference = 3300;
164d42139a3SMarc Pignat adc->channels = channels;
165d42139a3SMarc Pignat mutex_init(&adc->lock);
166d42139a3SMarc Pignat
167d42139a3SMarc Pignat mutex_lock(&adc->lock);
168d42139a3SMarc Pignat
16995de3b25SJean Delvare spi_set_drvdata(spi, adc);
170d42139a3SMarc Pignat
171d42139a3SMarc Pignat for (i = 0; i < 3 + adc->channels; i++) {
172d42139a3SMarc Pignat status = device_create_file(&spi->dev, &ad_input[i].dev_attr);
173d42139a3SMarc Pignat if (status) {
174d42139a3SMarc Pignat dev_err(&spi->dev, "device_create_file failed.\n");
175d42139a3SMarc Pignat goto out_err;
176d42139a3SMarc Pignat }
177d42139a3SMarc Pignat }
178d42139a3SMarc Pignat
179d42139a3SMarc Pignat adc->hwmon_dev = hwmon_device_register(&spi->dev);
180d42139a3SMarc Pignat if (IS_ERR(adc->hwmon_dev)) {
181d42139a3SMarc Pignat dev_err(&spi->dev, "hwmon_device_register failed.\n");
182d42139a3SMarc Pignat status = PTR_ERR(adc->hwmon_dev);
183d42139a3SMarc Pignat goto out_err;
184d42139a3SMarc Pignat }
185d42139a3SMarc Pignat
186d42139a3SMarc Pignat mutex_unlock(&adc->lock);
187d42139a3SMarc Pignat return 0;
188d42139a3SMarc Pignat
189d42139a3SMarc Pignat out_err:
190d42139a3SMarc Pignat for (i--; i >= 0; i--)
191d42139a3SMarc Pignat device_remove_file(&spi->dev, &ad_input[i].dev_attr);
192d42139a3SMarc Pignat
193d42139a3SMarc Pignat mutex_unlock(&adc->lock);
194d42139a3SMarc Pignat return status;
195d42139a3SMarc Pignat }
196d42139a3SMarc Pignat
adcxx_remove(struct spi_device * spi)197*a0386bbaSUwe Kleine-König static void adcxx_remove(struct spi_device *spi)
198d42139a3SMarc Pignat {
19995de3b25SJean Delvare struct adcxx *adc = spi_get_drvdata(spi);
200d42139a3SMarc Pignat int i;
201d42139a3SMarc Pignat
202d42139a3SMarc Pignat mutex_lock(&adc->lock);
203d42139a3SMarc Pignat hwmon_device_unregister(adc->hwmon_dev);
204d42139a3SMarc Pignat for (i = 0; i < 3 + adc->channels; i++)
205d42139a3SMarc Pignat device_remove_file(&spi->dev, &ad_input[i].dev_attr);
206d42139a3SMarc Pignat
207d42139a3SMarc Pignat mutex_unlock(&adc->lock);
208d42139a3SMarc Pignat }
209d42139a3SMarc Pignat
210d2a5c10fSAnton Vorontsov static const struct spi_device_id adcxx_ids[] = {
211d2a5c10fSAnton Vorontsov { "adcxx1s", 1 },
212d2a5c10fSAnton Vorontsov { "adcxx2s", 2 },
213d2a5c10fSAnton Vorontsov { "adcxx4s", 4 },
214d2a5c10fSAnton Vorontsov { "adcxx8s", 8 },
215d2a5c10fSAnton Vorontsov { },
216d42139a3SMarc Pignat };
217d2a5c10fSAnton Vorontsov MODULE_DEVICE_TABLE(spi, adcxx_ids);
218d42139a3SMarc Pignat
219d2a5c10fSAnton Vorontsov static struct spi_driver adcxx_driver = {
220d42139a3SMarc Pignat .driver = {
221d2a5c10fSAnton Vorontsov .name = "adcxx",
222d42139a3SMarc Pignat },
223d2a5c10fSAnton Vorontsov .id_table = adcxx_ids,
224d2a5c10fSAnton Vorontsov .probe = adcxx_probe,
2259e5e9b7aSBill Pemberton .remove = adcxx_remove,
226d42139a3SMarc Pignat };
227d42139a3SMarc Pignat
22891efffe2SAxel Lin module_spi_driver(adcxx_driver);
229d42139a3SMarc Pignat
230d42139a3SMarc Pignat MODULE_AUTHOR("Marc Pignat");
231d42139a3SMarc Pignat MODULE_DESCRIPTION("National Semiconductor adcxx8sxxx Linux driver");
232d42139a3SMarc Pignat MODULE_LICENSE("GPL");
233