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1// SPDX-License-Identifier: GPL-2.0-only
2/* linux/drivers/hwmon/s3c-hwmon.c
3 *
4 * Copyright (C) 2005, 2008, 2009 Simtec Electronics
5 * http://armlinux.simtec.co.uk/
6 * Ben Dooks <ben@simtec.co.uk>
7 *
8 * S3C24XX/S3C64XX ADC hwmon support
9*/
10
11#include <linux/module.h>
12#include <linux/slab.h>
13#include <linux/io.h>
14#include <linux/init.h>
15#include <linux/err.h>
16#include <linux/clk.h>
17#include <linux/interrupt.h>
18#include <linux/platform_device.h>
19
20#include <linux/hwmon.h>
21#include <linux/hwmon-sysfs.h>
22
23#include <linux/soc/samsung/s3c-adc.h>
24#include <linux/platform_data/hwmon-s3c.h>
25
26struct s3c_hwmon_attr {
27 struct sensor_device_attribute in;
28 struct sensor_device_attribute label;
29 char in_name[12];
30 char label_name[12];
31};
32
33/**
34 * struct s3c_hwmon - ADC hwmon client information
35 * @lock: Access lock to serialise the conversions.
36 * @client: The client we registered with the S3C ADC core.
37 * @hwmon_dev: The hwmon device we created.
38 * @attr: The holders for the channel attributes.
39*/
40struct s3c_hwmon {
41 struct mutex lock;
42 struct s3c_adc_client *client;
43 struct device *hwmon_dev;
44
45 struct s3c_hwmon_attr attrs[8];
46};
47
48/**
49 * s3c_hwmon_read_ch - read a value from a given adc channel.
50 * @dev: The device.
51 * @hwmon: Our state.
52 * @channel: The channel we're reading from.
53 *
54 * Read a value from the @channel with the proper locking and sleep until
55 * either the read completes or we timeout awaiting the ADC core to get
56 * back to us.
57 */
58static int s3c_hwmon_read_ch(struct device *dev,
59 struct s3c_hwmon *hwmon, int channel)
60{
61 int ret;
62
63 ret = mutex_lock_interruptible(&hwmon->lock);
64 if (ret < 0)
65 return ret;
66
67 dev_dbg(dev, "reading channel %d\n", channel);
68
69 ret = s3c_adc_read(hwmon->client, channel);
70 mutex_unlock(&hwmon->lock);
71
72 return ret;
73}
74
75#ifdef CONFIG_SENSORS_S3C_RAW
76/**
77 * s3c_hwmon_show_raw - show a conversion from the raw channel number.
78 * @dev: The device that the attribute belongs to.
79 * @attr: The attribute being read.
80 * @buf: The result buffer.
81 *
82 * This show deals with the raw attribute, registered for each possible
83 * ADC channel. This does a conversion and returns the raw (un-scaled)
84 * value returned from the hardware.
85 */
86static ssize_t s3c_hwmon_show_raw(struct device *dev,
87 struct device_attribute *attr, char *buf)
88{
89 struct s3c_hwmon *adc = dev_get_drvdata(dev);
90 struct sensor_device_attribute *sa = to_sensor_dev_attr(attr);
91 int ret;
92
93 ret = s3c_hwmon_read_ch(dev, adc, sa->index);
94
95 return (ret < 0) ? ret : snprintf(buf, PAGE_SIZE, "%d\n", ret);
96}
97
98static SENSOR_DEVICE_ATTR(adc0_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 0);
99static SENSOR_DEVICE_ATTR(adc1_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 1);
100static SENSOR_DEVICE_ATTR(adc2_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 2);
101static SENSOR_DEVICE_ATTR(adc3_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 3);
102static SENSOR_DEVICE_ATTR(adc4_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 4);
103static SENSOR_DEVICE_ATTR(adc5_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 5);
104static SENSOR_DEVICE_ATTR(adc6_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 6);
105static SENSOR_DEVICE_ATTR(adc7_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, 7);
106
107static struct attribute *s3c_hwmon_attrs[9] = {
108 &sensor_dev_attr_adc0_raw.dev_attr.attr,
109 &sensor_dev_attr_adc1_raw.dev_attr.attr,
110 &sensor_dev_attr_adc2_raw.dev_attr.attr,
111 &sensor_dev_attr_adc3_raw.dev_attr.attr,
112 &sensor_dev_attr_adc4_raw.dev_attr.attr,
113 &sensor_dev_attr_adc5_raw.dev_attr.attr,
114 &sensor_dev_attr_adc6_raw.dev_attr.attr,
115 &sensor_dev_attr_adc7_raw.dev_attr.attr,
116 NULL,
117};
118
119static struct attribute_group s3c_hwmon_attrgroup = {
120 .attrs = s3c_hwmon_attrs,
121};
122
123static inline int s3c_hwmon_add_raw(struct device *dev)
124{
125 return sysfs_create_group(&dev->kobj, &s3c_hwmon_attrgroup);
126}
127
128static inline void s3c_hwmon_remove_raw(struct device *dev)
129{
130 sysfs_remove_group(&dev->kobj, &s3c_hwmon_attrgroup);
131}
132
133#else
134
135static inline int s3c_hwmon_add_raw(struct device *dev) { return 0; }
136static inline void s3c_hwmon_remove_raw(struct device *dev) { }
137
138#endif /* CONFIG_SENSORS_S3C_RAW */
139
140/**
141 * s3c_hwmon_ch_show - show value of a given channel
142 * @dev: The device that the attribute belongs to.
143 * @attr: The attribute being read.
144 * @buf: The result buffer.
145 *
146 * Read a value from the ADC and scale it before returning it to the
147 * caller. The scale factor is gained from the channel configuration
148 * passed via the platform data when the device was registered.
149 */
150static ssize_t s3c_hwmon_ch_show(struct device *dev,
151 struct device_attribute *attr,
152 char *buf)
153{
154 struct sensor_device_attribute *sen_attr = to_sensor_dev_attr(attr);
155 struct s3c_hwmon *hwmon = dev_get_drvdata(dev);
156 struct s3c_hwmon_pdata *pdata = dev_get_platdata(dev);
157 struct s3c_hwmon_chcfg *cfg;
158 int ret;
159
160 cfg = pdata->in[sen_attr->index];
161
162 ret = s3c_hwmon_read_ch(dev, hwmon, sen_attr->index);
163 if (ret < 0)
164 return ret;
165
166 ret *= cfg->mult;
167 ret = DIV_ROUND_CLOSEST(ret, cfg->div);
168
169 return sysfs_emit(buf, "%d\n", ret);
170}
171
172/**
173 * s3c_hwmon_label_show - show label name of the given channel.
174 * @dev: The device that the attribute belongs to.
175 * @attr: The attribute being read.
176 * @buf: The result buffer.
177 *
178 * Return the label name of a given channel
179 */
180static ssize_t s3c_hwmon_label_show(struct device *dev,
181 struct device_attribute *attr,
182 char *buf)
183{
184 struct sensor_device_attribute *sen_attr = to_sensor_dev_attr(attr);
185 struct s3c_hwmon_pdata *pdata = dev_get_platdata(dev);
186 struct s3c_hwmon_chcfg *cfg;
187
188 cfg = pdata->in[sen_attr->index];
189
190 return sysfs_emit(buf, "%s\n", cfg->name);
191}
192
193/**
194 * s3c_hwmon_create_attr - create hwmon attribute for given channel.
195 * @dev: The device to create the attribute on.
196 * @cfg: The channel configuration passed from the platform data.
197 * @channel: The ADC channel number to process.
198 *
199 * Create the scaled attribute for use with hwmon from the specified
200 * platform data in @pdata. The sysfs entry is handled by the routine
201 * s3c_hwmon_ch_show().
202 *
203 * The attribute name is taken from the configuration data if present
204 * otherwise the name is taken by concatenating in_ with the channel
205 * number.
206 */
207static int s3c_hwmon_create_attr(struct device *dev,
208 struct s3c_hwmon_chcfg *cfg,
209 struct s3c_hwmon_attr *attrs,
210 int channel)
211{
212 struct sensor_device_attribute *attr;
213 int ret;
214
215 snprintf(attrs->in_name, sizeof(attrs->in_name), "in%d_input", channel);
216
217 attr = &attrs->in;
218 attr->index = channel;
219 sysfs_attr_init(&attr->dev_attr.attr);
220 attr->dev_attr.attr.name = attrs->in_name;
221 attr->dev_attr.attr.mode = S_IRUGO;
222 attr->dev_attr.show = s3c_hwmon_ch_show;
223
224 ret = device_create_file(dev, &attr->dev_attr);
225 if (ret < 0) {
226 dev_err(dev, "failed to create input attribute\n");
227 return ret;
228 }
229
230 /* if this has a name, add a label */
231 if (cfg->name) {
232 snprintf(attrs->label_name, sizeof(attrs->label_name),
233 "in%d_label", channel);
234
235 attr = &attrs->label;
236 attr->index = channel;
237 sysfs_attr_init(&attr->dev_attr.attr);
238 attr->dev_attr.attr.name = attrs->label_name;
239 attr->dev_attr.attr.mode = S_IRUGO;
240 attr->dev_attr.show = s3c_hwmon_label_show;
241
242 ret = device_create_file(dev, &attr->dev_attr);
243 if (ret < 0) {
244 device_remove_file(dev, &attrs->in.dev_attr);
245 dev_err(dev, "failed to create label attribute\n");
246 }
247 }
248
249 return ret;
250}
251
252static void s3c_hwmon_remove_attr(struct device *dev,
253 struct s3c_hwmon_attr *attrs)
254{
255 device_remove_file(dev, &attrs->in.dev_attr);
256 device_remove_file(dev, &attrs->label.dev_attr);
257}
258
259/**
260 * s3c_hwmon_probe - device probe entry.
261 * @dev: The device being probed.
262*/
263static int s3c_hwmon_probe(struct platform_device *dev)
264{
265 struct s3c_hwmon_pdata *pdata = dev_get_platdata(&dev->dev);
266 struct s3c_hwmon *hwmon;
267 int ret = 0;
268 int i;
269
270 if (!pdata) {
271 dev_err(&dev->dev, "no platform data supplied\n");
272 return -EINVAL;
273 }
274
275 hwmon = devm_kzalloc(&dev->dev, sizeof(struct s3c_hwmon), GFP_KERNEL);
276 if (hwmon == NULL)
277 return -ENOMEM;
278
279 platform_set_drvdata(dev, hwmon);
280
281 mutex_init(&hwmon->lock);
282
283 /* Register with the core ADC driver. */
284
285 hwmon->client = s3c_adc_register(dev, NULL, NULL, 0);
286 if (IS_ERR(hwmon->client)) {
287 dev_err(&dev->dev, "cannot register adc\n");
288 return PTR_ERR(hwmon->client);
289 }
290
291 /* add attributes for our adc devices. */
292
293 ret = s3c_hwmon_add_raw(&dev->dev);
294 if (ret)
295 goto err_registered;
296
297 /* register with the hwmon core */
298
299 hwmon->hwmon_dev = hwmon_device_register(&dev->dev);
300 if (IS_ERR(hwmon->hwmon_dev)) {
301 dev_err(&dev->dev, "error registering with hwmon\n");
302 ret = PTR_ERR(hwmon->hwmon_dev);
303 goto err_raw_attribute;
304 }
305
306 for (i = 0; i < ARRAY_SIZE(pdata->in); i++) {
307 struct s3c_hwmon_chcfg *cfg = pdata->in[i];
308
309 if (!cfg)
310 continue;
311
312 if (cfg->mult >= 0x10000)
313 dev_warn(&dev->dev,
314 "channel %d multiplier too large\n",
315 i);
316
317 if (cfg->div == 0) {
318 dev_err(&dev->dev, "channel %d divider zero\n", i);
319 continue;
320 }
321
322 ret = s3c_hwmon_create_attr(&dev->dev, pdata->in[i],
323 &hwmon->attrs[i], i);
324 if (ret) {
325 dev_err(&dev->dev,
326 "error creating channel %d\n", i);
327
328 for (i--; i >= 0; i--)
329 s3c_hwmon_remove_attr(&dev->dev,
330 &hwmon->attrs[i]);
331
332 goto err_hwmon_register;
333 }
334 }
335
336 return 0;
337
338 err_hwmon_register:
339 hwmon_device_unregister(hwmon->hwmon_dev);
340
341 err_raw_attribute:
342 s3c_hwmon_remove_raw(&dev->dev);
343
344 err_registered:
345 s3c_adc_release(hwmon->client);
346
347 return ret;
348}
349
350static int s3c_hwmon_remove(struct platform_device *dev)
351{
352 struct s3c_hwmon *hwmon = platform_get_drvdata(dev);
353 int i;
354
355 s3c_hwmon_remove_raw(&dev->dev);
356
357 for (i = 0; i < ARRAY_SIZE(hwmon->attrs); i++)
358 s3c_hwmon_remove_attr(&dev->dev, &hwmon->attrs[i]);
359
360 hwmon_device_unregister(hwmon->hwmon_dev);
361 s3c_adc_release(hwmon->client);
362
363 return 0;
364}
365
366static struct platform_driver s3c_hwmon_driver = {
367 .driver = {
368 .name = "s3c-hwmon",
369 },
370 .probe = s3c_hwmon_probe,
371 .remove = s3c_hwmon_remove,
372};
373
374module_platform_driver(s3c_hwmon_driver);
375
376MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
377MODULE_DESCRIPTION("S3C ADC HWMon driver");
378MODULE_LICENSE("GPL v2");
379MODULE_ALIAS("platform:s3c-hwmon");