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1 | /* linux/drivers/hwmon/s3c-hwmon.c |
2 | * |
3 | * Copyright (C) 2005, 2008, 2009 Simtec Electronics |
4 | * http://armlinux.simtec.co.uk/ |
5 | * Ben Dooks <ben@simtec.co.uk> |
6 | * |
7 | * S3C24XX/S3C64XX ADC hwmon support |
8 | * |
9 | * This program is free software; you can redistribute it and/or modify |
10 | * it under the terms of the GNU General Public License version 2 as |
11 | * published by the Free Software Foundation. |
12 | * |
13 | * This program is distributed in the hope that it will be useful, |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
16 | * GNU General Public License for more details. |
17 | * |
18 | * You should have received a copy of the GNU General Public License |
19 | * along with this program; if not, write to the Free Software |
20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
21 | */ |
22 | |
23 | #include <linux/module.h> |
24 | #include <linux/slab.h> |
25 | #include <linux/delay.h> |
26 | #include <linux/io.h> |
27 | #include <linux/init.h> |
28 | #include <linux/err.h> |
29 | #include <linux/clk.h> |
30 | #include <linux/interrupt.h> |
31 | #include <linux/platform_device.h> |
32 | |
33 | #include <linux/hwmon.h> |
34 | #include <linux/hwmon-sysfs.h> |
35 | |
36 | #include <plat/adc.h> |
37 | #include <plat/hwmon.h> |
38 | |
39 | struct s3c_hwmon_attr { |
40 | struct sensor_device_attribute in; |
41 | struct sensor_device_attribute label; |
42 | char in_name[12]; |
43 | char label_name[12]; |
44 | }; |
45 | |
46 | /** |
47 | * struct s3c_hwmon - ADC hwmon client information |
48 | * @lock: Access lock to serialise the conversions. |
49 | * @client: The client we registered with the S3C ADC core. |
50 | * @hwmon_dev: The hwmon device we created. |
51 | * @attr: The holders for the channel attributes. |
52 | */ |
53 | struct s3c_hwmon { |
54 | struct mutex lock; |
55 | struct s3c_adc_client *client; |
56 | struct device *hwmon_dev; |
57 | |
58 | struct s3c_hwmon_attr attrs[8]; |
59 | }; |
60 | |
61 | /** |
62 | * s3c_hwmon_read_ch - read a value from a given adc channel. |
63 | * @dev: The device. |
64 | * @hwmon: Our state. |
65 | * @channel: The channel we're reading from. |
66 | * |
67 | * Read a value from the @channel with the proper locking and sleep until |
68 | * either the read completes or we timeout awaiting the ADC core to get |
69 | * back to us. |
70 | */ |
71 | static int s3c_hwmon_read_ch(struct device *dev, |
72 | struct s3c_hwmon *hwmon, int channel) |
73 | { |
74 | int ret; |
75 | |
76 | ret = mutex_lock_interruptible(&hwmon->lock); |
77 | if (ret < 0) |
78 | return ret; |
79 | |
80 | dev_dbg(dev, "reading channel %d\n", channel); |
81 | |
82 | ret = s3c_adc_read(hwmon->client, channel); |
83 | mutex_unlock(&hwmon->lock); |
84 | |
85 | return ret; |
86 | } |
87 | |
88 | #ifdef CONFIG_SENSORS_S3C_RAW |
89 | /** |
90 | * s3c_hwmon_show_raw - show a conversion from the raw channel number. |
91 | * @dev: The device that the attribute belongs to. |
92 | * @attr: The attribute being read. |
93 | * @buf: The result buffer. |
94 | * |
95 | * This show deals with the raw attribute, registered for each possible |
96 | * ADC channel. This does a conversion and returns the raw (un-scaled) |
97 | * value returned from the hardware. |
98 | */ |
99 | static ssize_t s3c_hwmon_show_raw(struct device *dev, |
100 | struct device_attribute *attr, char *buf) |
101 | { |
102 | struct s3c_hwmon *adc = platform_get_drvdata(to_platform_device(dev)); |
103 | struct sensor_device_attribute *sa = to_sensor_dev_attr(attr); |
104 | int ret; |
105 | |
106 | ret = s3c_hwmon_read_ch(dev, adc, sa->index); |
107 | |
108 | return (ret < 0) ? ret : snprintf(buf, PAGE_SIZE, "%d\n", ret); |
109 | } |
110 | |
111 | #define DEF_ADC_ATTR(x) \ |
112 | static SENSOR_DEVICE_ATTR(adc##x##_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, x) |
113 | |
114 | DEF_ADC_ATTR(0); |
115 | DEF_ADC_ATTR(1); |
116 | DEF_ADC_ATTR(2); |
117 | DEF_ADC_ATTR(3); |
118 | DEF_ADC_ATTR(4); |
119 | DEF_ADC_ATTR(5); |
120 | DEF_ADC_ATTR(6); |
121 | DEF_ADC_ATTR(7); |
122 | |
123 | static struct attribute *s3c_hwmon_attrs[9] = { |
124 | &sensor_dev_attr_adc0_raw.dev_attr.attr, |
125 | &sensor_dev_attr_adc1_raw.dev_attr.attr, |
126 | &sensor_dev_attr_adc2_raw.dev_attr.attr, |
127 | &sensor_dev_attr_adc3_raw.dev_attr.attr, |
128 | &sensor_dev_attr_adc4_raw.dev_attr.attr, |
129 | &sensor_dev_attr_adc5_raw.dev_attr.attr, |
130 | &sensor_dev_attr_adc6_raw.dev_attr.attr, |
131 | &sensor_dev_attr_adc7_raw.dev_attr.attr, |
132 | NULL, |
133 | }; |
134 | |
135 | static struct attribute_group s3c_hwmon_attrgroup = { |
136 | .attrs = s3c_hwmon_attrs, |
137 | }; |
138 | |
139 | static inline int s3c_hwmon_add_raw(struct device *dev) |
140 | { |
141 | return sysfs_create_group(&dev->kobj, &s3c_hwmon_attrgroup); |
142 | } |
143 | |
144 | static inline void s3c_hwmon_remove_raw(struct device *dev) |
145 | { |
146 | sysfs_remove_group(&dev->kobj, &s3c_hwmon_attrgroup); |
147 | } |
148 | |
149 | #else |
150 | |
151 | static inline int s3c_hwmon_add_raw(struct device *dev) { return 0; } |
152 | static inline void s3c_hwmon_remove_raw(struct device *dev) { } |
153 | |
154 | #endif /* CONFIG_SENSORS_S3C_RAW */ |
155 | |
156 | /** |
157 | * s3c_hwmon_ch_show - show value of a given channel |
158 | * @dev: The device that the attribute belongs to. |
159 | * @attr: The attribute being read. |
160 | * @buf: The result buffer. |
161 | * |
162 | * Read a value from the ADC and scale it before returning it to the |
163 | * caller. The scale factor is gained from the channel configuration |
164 | * passed via the platform data when the device was registered. |
165 | */ |
166 | static ssize_t s3c_hwmon_ch_show(struct device *dev, |
167 | struct device_attribute *attr, |
168 | char *buf) |
169 | { |
170 | struct sensor_device_attribute *sen_attr = to_sensor_dev_attr(attr); |
171 | struct s3c_hwmon *hwmon = platform_get_drvdata(to_platform_device(dev)); |
172 | struct s3c_hwmon_pdata *pdata = dev->platform_data; |
173 | struct s3c_hwmon_chcfg *cfg; |
174 | int ret; |
175 | |
176 | cfg = pdata->in[sen_attr->index]; |
177 | |
178 | ret = s3c_hwmon_read_ch(dev, hwmon, sen_attr->index); |
179 | if (ret < 0) |
180 | return ret; |
181 | |
182 | ret *= cfg->mult; |
183 | ret = DIV_ROUND_CLOSEST(ret, cfg->div); |
184 | |
185 | return snprintf(buf, PAGE_SIZE, "%d\n", ret); |
186 | } |
187 | |
188 | /** |
189 | * s3c_hwmon_label_show - show label name of the given channel. |
190 | * @dev: The device that the attribute belongs to. |
191 | * @attr: The attribute being read. |
192 | * @buf: The result buffer. |
193 | * |
194 | * Return the label name of a given channel |
195 | */ |
196 | static ssize_t s3c_hwmon_label_show(struct device *dev, |
197 | struct device_attribute *attr, |
198 | char *buf) |
199 | { |
200 | struct sensor_device_attribute *sen_attr = to_sensor_dev_attr(attr); |
201 | struct s3c_hwmon_pdata *pdata = dev->platform_data; |
202 | struct s3c_hwmon_chcfg *cfg; |
203 | |
204 | cfg = pdata->in[sen_attr->index]; |
205 | |
206 | return snprintf(buf, PAGE_SIZE, "%s\n", cfg->name); |
207 | } |
208 | |
209 | /** |
210 | * s3c_hwmon_create_attr - create hwmon attribute for given channel. |
211 | * @dev: The device to create the attribute on. |
212 | * @cfg: The channel configuration passed from the platform data. |
213 | * @channel: The ADC channel number to process. |
214 | * |
215 | * Create the scaled attribute for use with hwmon from the specified |
216 | * platform data in @pdata. The sysfs entry is handled by the routine |
217 | * s3c_hwmon_ch_show(). |
218 | * |
219 | * The attribute name is taken from the configuration data if present |
220 | * otherwise the name is taken by concatenating in_ with the channel |
221 | * number. |
222 | */ |
223 | static int s3c_hwmon_create_attr(struct device *dev, |
224 | struct s3c_hwmon_chcfg *cfg, |
225 | struct s3c_hwmon_attr *attrs, |
226 | int channel) |
227 | { |
228 | struct sensor_device_attribute *attr; |
229 | int ret; |
230 | |
231 | snprintf(attrs->in_name, sizeof(attrs->in_name), "in%d_input", channel); |
232 | |
233 | attr = &attrs->in; |
234 | attr->index = channel; |
235 | sysfs_attr_init(&attr->dev_attr.attr); |
236 | attr->dev_attr.attr.name = attrs->in_name; |
237 | attr->dev_attr.attr.mode = S_IRUGO; |
238 | attr->dev_attr.show = s3c_hwmon_ch_show; |
239 | |
240 | ret = device_create_file(dev, &attr->dev_attr); |
241 | if (ret < 0) { |
242 | dev_err(dev, "failed to create input attribute\n"); |
243 | return ret; |
244 | } |
245 | |
246 | /* if this has a name, add a label */ |
247 | if (cfg->name) { |
248 | snprintf(attrs->label_name, sizeof(attrs->label_name), |
249 | "in%d_label", channel); |
250 | |
251 | attr = &attrs->label; |
252 | attr->index = channel; |
253 | sysfs_attr_init(&attr->dev_attr.attr); |
254 | attr->dev_attr.attr.name = attrs->label_name; |
255 | attr->dev_attr.attr.mode = S_IRUGO; |
256 | attr->dev_attr.show = s3c_hwmon_label_show; |
257 | |
258 | ret = device_create_file(dev, &attr->dev_attr); |
259 | if (ret < 0) { |
260 | device_remove_file(dev, &attrs->in.dev_attr); |
261 | dev_err(dev, "failed to create label attribute\n"); |
262 | } |
263 | } |
264 | |
265 | return ret; |
266 | } |
267 | |
268 | static void s3c_hwmon_remove_attr(struct device *dev, |
269 | struct s3c_hwmon_attr *attrs) |
270 | { |
271 | device_remove_file(dev, &attrs->in.dev_attr); |
272 | device_remove_file(dev, &attrs->label.dev_attr); |
273 | } |
274 | |
275 | /** |
276 | * s3c_hwmon_probe - device probe entry. |
277 | * @dev: The device being probed. |
278 | */ |
279 | static int __devinit s3c_hwmon_probe(struct platform_device *dev) |
280 | { |
281 | struct s3c_hwmon_pdata *pdata = dev->dev.platform_data; |
282 | struct s3c_hwmon *hwmon; |
283 | int ret = 0; |
284 | int i; |
285 | |
286 | if (!pdata) { |
287 | dev_err(&dev->dev, "no platform data supplied\n"); |
288 | return -EINVAL; |
289 | } |
290 | |
291 | hwmon = devm_kzalloc(&dev->dev, sizeof(struct s3c_hwmon), GFP_KERNEL); |
292 | if (hwmon == NULL) { |
293 | dev_err(&dev->dev, "no memory\n"); |
294 | return -ENOMEM; |
295 | } |
296 | |
297 | platform_set_drvdata(dev, hwmon); |
298 | |
299 | mutex_init(&hwmon->lock); |
300 | |
301 | /* Register with the core ADC driver. */ |
302 | |
303 | hwmon->client = s3c_adc_register(dev, NULL, NULL, 0); |
304 | if (IS_ERR(hwmon->client)) { |
305 | dev_err(&dev->dev, "cannot register adc\n"); |
306 | return PTR_ERR(hwmon->client); |
307 | } |
308 | |
309 | /* add attributes for our adc devices. */ |
310 | |
311 | ret = s3c_hwmon_add_raw(&dev->dev); |
312 | if (ret) |
313 | goto err_registered; |
314 | |
315 | /* register with the hwmon core */ |
316 | |
317 | hwmon->hwmon_dev = hwmon_device_register(&dev->dev); |
318 | if (IS_ERR(hwmon->hwmon_dev)) { |
319 | dev_err(&dev->dev, "error registering with hwmon\n"); |
320 | ret = PTR_ERR(hwmon->hwmon_dev); |
321 | goto err_raw_attribute; |
322 | } |
323 | |
324 | for (i = 0; i < ARRAY_SIZE(pdata->in); i++) { |
325 | struct s3c_hwmon_chcfg *cfg = pdata->in[i]; |
326 | |
327 | if (!cfg) |
328 | continue; |
329 | |
330 | if (cfg->mult >= 0x10000) |
331 | dev_warn(&dev->dev, |
332 | "channel %d multiplier too large\n", |
333 | i); |
334 | |
335 | if (cfg->div == 0) { |
336 | dev_err(&dev->dev, "channel %d divider zero\n", i); |
337 | continue; |
338 | } |
339 | |
340 | ret = s3c_hwmon_create_attr(&dev->dev, pdata->in[i], |
341 | &hwmon->attrs[i], i); |
342 | if (ret) { |
343 | dev_err(&dev->dev, |
344 | "error creating channel %d\n", i); |
345 | |
346 | for (i--; i >= 0; i--) |
347 | s3c_hwmon_remove_attr(&dev->dev, |
348 | &hwmon->attrs[i]); |
349 | |
350 | goto err_hwmon_register; |
351 | } |
352 | } |
353 | |
354 | return 0; |
355 | |
356 | err_hwmon_register: |
357 | hwmon_device_unregister(hwmon->hwmon_dev); |
358 | |
359 | err_raw_attribute: |
360 | s3c_hwmon_remove_raw(&dev->dev); |
361 | |
362 | err_registered: |
363 | s3c_adc_release(hwmon->client); |
364 | |
365 | return ret; |
366 | } |
367 | |
368 | static int __devexit s3c_hwmon_remove(struct platform_device *dev) |
369 | { |
370 | struct s3c_hwmon *hwmon = platform_get_drvdata(dev); |
371 | int i; |
372 | |
373 | s3c_hwmon_remove_raw(&dev->dev); |
374 | |
375 | for (i = 0; i < ARRAY_SIZE(hwmon->attrs); i++) |
376 | s3c_hwmon_remove_attr(&dev->dev, &hwmon->attrs[i]); |
377 | |
378 | hwmon_device_unregister(hwmon->hwmon_dev); |
379 | s3c_adc_release(hwmon->client); |
380 | |
381 | return 0; |
382 | } |
383 | |
384 | static struct platform_driver s3c_hwmon_driver = { |
385 | .driver = { |
386 | .name = "s3c-hwmon", |
387 | .owner = THIS_MODULE, |
388 | }, |
389 | .probe = s3c_hwmon_probe, |
390 | .remove = __devexit_p(s3c_hwmon_remove), |
391 | }; |
392 | |
393 | module_platform_driver(s3c_hwmon_driver); |
394 | |
395 | MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); |
396 | MODULE_DESCRIPTION("S3C ADC HWMon driver"); |
397 | MODULE_LICENSE("GPL v2"); |
398 | MODULE_ALIAS("platform:s3c-hwmon"); |
399 |
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