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14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/init.h>
17#include <linux/err.h>
18#include <linux/slab.h>
19#include <linux/mutex.h>
20#include <linux/device.h>
21#include <linux/sysfs.h>
22#include <linux/hwmon.h>
23#include <linux/hwmon-sysfs.h>
24#include <linux/platform_device.h>
25#include <linux/platform_data/max197.h>
26
27#define MAX199_LIMIT 4000
28#define MAX197_LIMIT 10000
29
30#define MAX197_NUM_CH 8
31
32
33#define MAX197_BIP (1 << 3)
34#define MAX197_RNG (1 << 4)
35
36#define MAX197_SCALE 12207
37
38
39enum max197_chips { max197, max199 };
40
41
42
43
44
45
46
47
48
49
50struct max197_data {
51 struct max197_platform_data *pdata;
52 struct device *hwmon_dev;
53 struct mutex lock;
54 int limit;
55 bool scale;
56 u8 ctrl_bytes[MAX197_NUM_CH];
57};
58
59static inline void max197_set_unipolarity(struct max197_data *data, int channel)
60{
61 data->ctrl_bytes[channel] &= ~MAX197_BIP;
62}
63
64static inline void max197_set_bipolarity(struct max197_data *data, int channel)
65{
66 data->ctrl_bytes[channel] |= MAX197_BIP;
67}
68
69static inline void max197_set_half_range(struct max197_data *data, int channel)
70{
71 data->ctrl_bytes[channel] &= ~MAX197_RNG;
72}
73
74static inline void max197_set_full_range(struct max197_data *data, int channel)
75{
76 data->ctrl_bytes[channel] |= MAX197_RNG;
77}
78
79static inline bool max197_is_bipolar(struct max197_data *data, int channel)
80{
81 return data->ctrl_bytes[channel] & MAX197_BIP;
82}
83
84static inline bool max197_is_full_range(struct max197_data *data, int channel)
85{
86 return data->ctrl_bytes[channel] & MAX197_RNG;
87}
88
89
90static ssize_t max197_show_range(struct device *dev,
91 struct device_attribute *devattr, char *buf)
92{
93 struct max197_data *data = dev_get_drvdata(dev);
94 struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
95 int channel = attr->index;
96 bool is_min = attr->nr;
97 int range;
98
99 if (mutex_lock_interruptible(&data->lock))
100 return -ERESTARTSYS;
101
102 range = max197_is_full_range(data, channel) ?
103 data->limit : data->limit / 2;
104 if (is_min) {
105 if (max197_is_bipolar(data, channel))
106 range = -range;
107 else
108 range = 0;
109 }
110
111 mutex_unlock(&data->lock);
112
113 return sprintf(buf, "%d\n", range);
114}
115
116
117static ssize_t max197_store_range(struct device *dev,
118 struct device_attribute *devattr,
119 const char *buf, size_t count)
120{
121 struct max197_data *data = dev_get_drvdata(dev);
122 struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
123 int channel = attr->index;
124 bool is_min = attr->nr;
125 long value;
126 int half = data->limit / 2;
127 int full = data->limit;
128
129 if (kstrtol(buf, 10, &value))
130 return -EINVAL;
131
132 if (is_min) {
133 if (value <= -full)
134 value = -full;
135 else if (value < 0)
136 value = -half;
137 else
138 value = 0;
139 } else {
140 if (value >= full)
141 value = full;
142 else
143 value = half;
144 }
145
146 if (mutex_lock_interruptible(&data->lock))
147 return -ERESTARTSYS;
148
149 if (value == 0) {
150
151 max197_set_unipolarity(data, channel);
152 } else if (value == -half) {
153 max197_set_bipolarity(data, channel);
154 max197_set_half_range(data, channel);
155 } else if (value == -full) {
156 max197_set_bipolarity(data, channel);
157 max197_set_full_range(data, channel);
158 } else if (value == half) {
159
160 max197_set_half_range(data, channel);
161 } else if (value == full) {
162
163 max197_set_full_range(data, channel);
164 }
165
166 mutex_unlock(&data->lock);
167
168 return count;
169}
170
171
172static ssize_t max197_show_input(struct device *dev,
173 struct device_attribute *devattr,
174 char *buf)
175{
176 struct max197_data *data = dev_get_drvdata(dev);
177 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
178 int channel = attr->index;
179 s32 value;
180 int ret;
181
182 if (mutex_lock_interruptible(&data->lock))
183 return -ERESTARTSYS;
184
185 ret = data->pdata->convert(data->ctrl_bytes[channel]);
186 if (ret < 0) {
187 dev_err(dev, "conversion failed\n");
188 goto unlock;
189 }
190 value = ret;
191
192
193
194
195
196 if (data->scale) {
197 value *= MAX197_SCALE;
198 if (max197_is_full_range(data, channel))
199 value *= 2;
200 value /= 10000;
201 }
202
203 ret = sprintf(buf, "%d\n", value);
204
205unlock:
206 mutex_unlock(&data->lock);
207 return ret;
208}
209
210static ssize_t max197_show_name(struct device *dev,
211 struct device_attribute *attr, char *buf)
212{
213 struct platform_device *pdev = to_platform_device(dev);
214 return sprintf(buf, "%s\n", pdev->name);
215}
216
217#define MAX197_SENSOR_DEVICE_ATTR_CH(chan) \
218 static SENSOR_DEVICE_ATTR(in##chan##_input, S_IRUGO, \
219 max197_show_input, NULL, chan); \
220 static SENSOR_DEVICE_ATTR_2(in##chan##_min, S_IRUGO | S_IWUSR, \
221 max197_show_range, \
222 max197_store_range, \
223 true, chan); \
224 static SENSOR_DEVICE_ATTR_2(in##chan##_max, S_IRUGO | S_IWUSR, \
225 max197_show_range, \
226 max197_store_range, \
227 false, chan)
228
229#define MAX197_SENSOR_DEV_ATTR_IN(chan) \
230 &sensor_dev_attr_in##chan##_input.dev_attr.attr, \
231 &sensor_dev_attr_in##chan##_max.dev_attr.attr, \
232 &sensor_dev_attr_in##chan##_min.dev_attr.attr
233
234static DEVICE_ATTR(name, S_IRUGO, max197_show_name, NULL);
235
236MAX197_SENSOR_DEVICE_ATTR_CH(0);
237MAX197_SENSOR_DEVICE_ATTR_CH(1);
238MAX197_SENSOR_DEVICE_ATTR_CH(2);
239MAX197_SENSOR_DEVICE_ATTR_CH(3);
240MAX197_SENSOR_DEVICE_ATTR_CH(4);
241MAX197_SENSOR_DEVICE_ATTR_CH(5);
242MAX197_SENSOR_DEVICE_ATTR_CH(6);
243MAX197_SENSOR_DEVICE_ATTR_CH(7);
244
245static const struct attribute_group max197_sysfs_group = {
246 .attrs = (struct attribute *[]) {
247 &dev_attr_name.attr,
248 MAX197_SENSOR_DEV_ATTR_IN(0),
249 MAX197_SENSOR_DEV_ATTR_IN(1),
250 MAX197_SENSOR_DEV_ATTR_IN(2),
251 MAX197_SENSOR_DEV_ATTR_IN(3),
252 MAX197_SENSOR_DEV_ATTR_IN(4),
253 MAX197_SENSOR_DEV_ATTR_IN(5),
254 MAX197_SENSOR_DEV_ATTR_IN(6),
255 MAX197_SENSOR_DEV_ATTR_IN(7),
256 NULL
257 },
258};
259
260static int max197_probe(struct platform_device *pdev)
261{
262 int ch, ret;
263 struct max197_data *data;
264 struct max197_platform_data *pdata = dev_get_platdata(&pdev->dev);
265 enum max197_chips chip = platform_get_device_id(pdev)->driver_data;
266
267 if (pdata == NULL) {
268 dev_err(&pdev->dev, "no platform data supplied\n");
269 return -EINVAL;
270 }
271
272 if (pdata->convert == NULL) {
273 dev_err(&pdev->dev, "no convert function supplied\n");
274 return -EINVAL;
275 }
276
277 data = devm_kzalloc(&pdev->dev, sizeof(struct max197_data), GFP_KERNEL);
278 if (!data) {
279 dev_err(&pdev->dev, "devm_kzalloc failed\n");
280 return -ENOMEM;
281 }
282
283 data->pdata = pdata;
284 mutex_init(&data->lock);
285
286 if (chip == max197) {
287 data->limit = MAX197_LIMIT;
288 data->scale = true;
289 } else {
290 data->limit = MAX199_LIMIT;
291 data->scale = false;
292 }
293
294 for (ch = 0; ch < MAX197_NUM_CH; ch++)
295 data->ctrl_bytes[ch] = (u8) ch;
296
297 platform_set_drvdata(pdev, data);
298
299 ret = sysfs_create_group(&pdev->dev.kobj, &max197_sysfs_group);
300 if (ret) {
301 dev_err(&pdev->dev, "sysfs create group failed\n");
302 return ret;
303 }
304
305 data->hwmon_dev = hwmon_device_register(&pdev->dev);
306 if (IS_ERR(data->hwmon_dev)) {
307 ret = PTR_ERR(data->hwmon_dev);
308 dev_err(&pdev->dev, "hwmon device register failed\n");
309 goto error;
310 }
311
312 return 0;
313
314error:
315 sysfs_remove_group(&pdev->dev.kobj, &max197_sysfs_group);
316 return ret;
317}
318
319static int max197_remove(struct platform_device *pdev)
320{
321 struct max197_data *data = platform_get_drvdata(pdev);
322
323 hwmon_device_unregister(data->hwmon_dev);
324 sysfs_remove_group(&pdev->dev.kobj, &max197_sysfs_group);
325
326 return 0;
327}
328
329static struct platform_device_id max197_device_ids[] = {
330 { "max197", max197 },
331 { "max199", max199 },
332 { }
333};
334MODULE_DEVICE_TABLE(platform, max197_device_ids);
335
336static struct platform_driver max197_driver = {
337 .driver = {
338 .name = "max197",
339 .owner = THIS_MODULE,
340 },
341 .probe = max197_probe,
342 .remove = max197_remove,
343 .id_table = max197_device_ids,
344};
345module_platform_driver(max197_driver);
346
347MODULE_LICENSE("GPL");
348MODULE_AUTHOR("Savoir-faire Linux Inc. <kernel@savoirfairelinux.com>");
349MODULE_DESCRIPTION("Maxim MAX197 A/D Converter driver");
350
