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cf35ad61 | 1 | /* |
35f73967 | 2 | * mcp4725.c - Support for Microchip MCP4725/6 |
cf35ad61 PM |
3 | * |
4 | * Copyright (C) 2012 Peter Meerwald <pmeerw@pmeerw.net> | |
5 | * | |
6 | * Based on max517 by Roland Stigge <stigge@antcom.de> | |
7 | * | |
8 | * This file is subject to the terms and conditions of version 2 of | |
9 | * the GNU General Public License. See the file COPYING in the main | |
10 | * directory of this archive for more details. | |
11 | * | |
12 | * driver for the Microchip I2C 12-bit digital-to-analog converter (DAC) | |
13 | * (7-bit I2C slave address 0x60, the three LSBs can be configured in | |
14 | * hardware) | |
cf35ad61 PM |
15 | */ |
16 | ||
17 | #include <linux/module.h> | |
cf35ad61 PM |
18 | #include <linux/i2c.h> |
19 | #include <linux/err.h> | |
f17b77d6 | 20 | #include <linux/delay.h> |
cf35ad61 PM |
21 | |
22 | #include <linux/iio/iio.h> | |
23 | #include <linux/iio/sysfs.h> | |
24 | ||
25 | #include <linux/iio/dac/mcp4725.h> | |
26 | ||
27 | #define MCP4725_DRV_NAME "mcp4725" | |
28 | ||
29 | struct mcp4725_data { | |
30 | struct i2c_client *client; | |
31 | u16 vref_mv; | |
32 | u16 dac_value; | |
155f1b41 PM |
33 | bool powerdown; |
34 | unsigned powerdown_mode; | |
cf35ad61 PM |
35 | }; |
36 | ||
cf35ad61 PM |
37 | static int mcp4725_suspend(struct device *dev) |
38 | { | |
a97dd069 PM |
39 | struct mcp4725_data *data = iio_priv(i2c_get_clientdata( |
40 | to_i2c_client(dev))); | |
cf35ad61 PM |
41 | u8 outbuf[2]; |
42 | ||
155f1b41 | 43 | outbuf[0] = (data->powerdown_mode + 1) << 4; |
cf35ad61 | 44 | outbuf[1] = 0; |
155f1b41 | 45 | data->powerdown = true; |
cf35ad61 | 46 | |
a97dd069 | 47 | return i2c_master_send(data->client, outbuf, 2); |
cf35ad61 PM |
48 | } |
49 | ||
50 | static int mcp4725_resume(struct device *dev) | |
51 | { | |
a97dd069 PM |
52 | struct mcp4725_data *data = iio_priv(i2c_get_clientdata( |
53 | to_i2c_client(dev))); | |
cf35ad61 PM |
54 | u8 outbuf[2]; |
55 | ||
56 | /* restore previous DAC value */ | |
57 | outbuf[0] = (data->dac_value >> 8) & 0xf; | |
58 | outbuf[1] = data->dac_value & 0xff; | |
155f1b41 | 59 | data->powerdown = false; |
cf35ad61 | 60 | |
a97dd069 | 61 | return i2c_master_send(data->client, outbuf, 2); |
cf35ad61 PM |
62 | } |
63 | ||
155f1b41 | 64 | #ifdef CONFIG_PM_SLEEP |
cf35ad61 PM |
65 | static SIMPLE_DEV_PM_OPS(mcp4725_pm_ops, mcp4725_suspend, mcp4725_resume); |
66 | #define MCP4725_PM_OPS (&mcp4725_pm_ops) | |
67 | #else | |
68 | #define MCP4725_PM_OPS NULL | |
69 | #endif | |
70 | ||
4fd313da | 71 | static ssize_t mcp4725_store_eeprom(struct device *dev, |
f17b77d6 PM |
72 | struct device_attribute *attr, const char *buf, size_t len) |
73 | { | |
74 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); | |
75 | struct mcp4725_data *data = iio_priv(indio_dev); | |
76 | int tries = 20; | |
77 | u8 inoutbuf[3]; | |
78 | bool state; | |
79 | int ret; | |
80 | ||
81 | ret = strtobool(buf, &state); | |
82 | if (ret < 0) | |
83 | return ret; | |
84 | ||
85 | if (!state) | |
86 | return 0; | |
87 | ||
88 | inoutbuf[0] = 0x60; /* write EEPROM */ | |
89 | inoutbuf[1] = data->dac_value >> 4; | |
90 | inoutbuf[2] = (data->dac_value & 0xf) << 4; | |
91 | ||
92 | ret = i2c_master_send(data->client, inoutbuf, 3); | |
93 | if (ret < 0) | |
94 | return ret; | |
95 | else if (ret != 3) | |
96 | return -EIO; | |
97 | ||
98 | /* wait for write complete, takes up to 50ms */ | |
99 | while (tries--) { | |
100 | msleep(20); | |
101 | ret = i2c_master_recv(data->client, inoutbuf, 3); | |
102 | if (ret < 0) | |
103 | return ret; | |
104 | else if (ret != 3) | |
105 | return -EIO; | |
106 | ||
107 | if (inoutbuf[0] & 0x80) | |
108 | break; | |
109 | } | |
110 | ||
111 | if (tries < 0) { | |
112 | dev_err(&data->client->dev, | |
113 | "mcp4725_store_eeprom() failed, incomplete\n"); | |
114 | return -EIO; | |
115 | } | |
116 | ||
117 | return len; | |
118 | } | |
119 | ||
120 | static IIO_DEVICE_ATTR(store_eeprom, S_IWUSR, NULL, mcp4725_store_eeprom, 0); | |
121 | ||
122 | static struct attribute *mcp4725_attributes[] = { | |
123 | &iio_dev_attr_store_eeprom.dev_attr.attr, | |
124 | NULL, | |
125 | }; | |
126 | ||
127 | static const struct attribute_group mcp4725_attribute_group = { | |
128 | .attrs = mcp4725_attributes, | |
129 | }; | |
130 | ||
155f1b41 PM |
131 | static const char * const mcp4725_powerdown_modes[] = { |
132 | "1kohm_to_gnd", | |
133 | "100kohm_to_gnd", | |
134 | "500kohm_to_gnd" | |
135 | }; | |
136 | ||
35f73967 AM |
137 | static const char * const mcp4726_powerdown_modes[] = { |
138 | "1kohm_to_gnd", | |
139 | "125kohm_to_gnd", | |
140 | "640kohm_to_gnd" | |
141 | }; | |
142 | ||
155f1b41 PM |
143 | static int mcp4725_get_powerdown_mode(struct iio_dev *indio_dev, |
144 | const struct iio_chan_spec *chan) | |
145 | { | |
146 | struct mcp4725_data *data = iio_priv(indio_dev); | |
147 | ||
148 | return data->powerdown_mode; | |
149 | } | |
150 | ||
151 | static int mcp4725_set_powerdown_mode(struct iio_dev *indio_dev, | |
152 | const struct iio_chan_spec *chan, unsigned mode) | |
153 | { | |
154 | struct mcp4725_data *data = iio_priv(indio_dev); | |
155 | ||
156 | data->powerdown_mode = mode; | |
157 | ||
158 | return 0; | |
159 | } | |
160 | ||
161 | static ssize_t mcp4725_read_powerdown(struct iio_dev *indio_dev, | |
162 | uintptr_t private, const struct iio_chan_spec *chan, char *buf) | |
163 | { | |
164 | struct mcp4725_data *data = iio_priv(indio_dev); | |
165 | ||
166 | return sprintf(buf, "%d\n", data->powerdown); | |
167 | } | |
168 | ||
169 | static ssize_t mcp4725_write_powerdown(struct iio_dev *indio_dev, | |
170 | uintptr_t private, const struct iio_chan_spec *chan, | |
171 | const char *buf, size_t len) | |
172 | { | |
173 | struct mcp4725_data *data = iio_priv(indio_dev); | |
174 | bool state; | |
175 | int ret; | |
176 | ||
177 | ret = strtobool(buf, &state); | |
178 | if (ret) | |
179 | return ret; | |
180 | ||
181 | if (state) | |
182 | ret = mcp4725_suspend(&data->client->dev); | |
183 | else | |
184 | ret = mcp4725_resume(&data->client->dev); | |
185 | if (ret < 0) | |
186 | return ret; | |
187 | ||
188 | return len; | |
189 | } | |
190 | ||
35f73967 AM |
191 | enum { |
192 | MCP4725, | |
193 | MCP4726, | |
194 | }; | |
195 | ||
196 | static const struct iio_enum mcp472x_powerdown_mode_enum[] = { | |
197 | [MCP4725] = { | |
198 | .items = mcp4725_powerdown_modes, | |
199 | .num_items = ARRAY_SIZE(mcp4725_powerdown_modes), | |
200 | .get = mcp4725_get_powerdown_mode, | |
201 | .set = mcp4725_set_powerdown_mode, | |
202 | }, | |
203 | [MCP4726] = { | |
204 | .items = mcp4726_powerdown_modes, | |
205 | .num_items = ARRAY_SIZE(mcp4726_powerdown_modes), | |
206 | .get = mcp4725_get_powerdown_mode, | |
207 | .set = mcp4725_set_powerdown_mode, | |
208 | }, | |
155f1b41 PM |
209 | }; |
210 | ||
211 | static const struct iio_chan_spec_ext_info mcp4725_ext_info[] = { | |
212 | { | |
213 | .name = "powerdown", | |
214 | .read = mcp4725_read_powerdown, | |
215 | .write = mcp4725_write_powerdown, | |
3704432f | 216 | .shared = IIO_SEPARATE, |
155f1b41 | 217 | }, |
35f73967 AM |
218 | IIO_ENUM("powerdown_mode", IIO_SEPARATE, |
219 | &mcp472x_powerdown_mode_enum[MCP4725]), | |
220 | IIO_ENUM_AVAILABLE("powerdown_mode", | |
221 | &mcp472x_powerdown_mode_enum[MCP4725]), | |
222 | { }, | |
223 | }; | |
224 | ||
225 | static const struct iio_chan_spec_ext_info mcp4726_ext_info[] = { | |
226 | { | |
227 | .name = "powerdown", | |
228 | .read = mcp4725_read_powerdown, | |
229 | .write = mcp4725_write_powerdown, | |
230 | .shared = IIO_SEPARATE, | |
231 | }, | |
232 | IIO_ENUM("powerdown_mode", IIO_SEPARATE, | |
233 | &mcp472x_powerdown_mode_enum[MCP4726]), | |
234 | IIO_ENUM_AVAILABLE("powerdown_mode", | |
235 | &mcp472x_powerdown_mode_enum[MCP4726]), | |
155f1b41 PM |
236 | { }, |
237 | }; | |
238 | ||
35f73967 AM |
239 | static const struct iio_chan_spec mcp472x_channel[] = { |
240 | [MCP4725] = { | |
241 | .type = IIO_VOLTAGE, | |
242 | .indexed = 1, | |
243 | .output = 1, | |
244 | .channel = 0, | |
245 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), | |
246 | .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), | |
247 | .ext_info = mcp4725_ext_info, | |
248 | }, | |
249 | [MCP4726] = { | |
250 | .type = IIO_VOLTAGE, | |
251 | .indexed = 1, | |
252 | .output = 1, | |
253 | .channel = 0, | |
254 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), | |
255 | .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), | |
256 | .ext_info = mcp4726_ext_info, | |
257 | }, | |
cf35ad61 PM |
258 | }; |
259 | ||
260 | static int mcp4725_set_value(struct iio_dev *indio_dev, int val) | |
261 | { | |
262 | struct mcp4725_data *data = iio_priv(indio_dev); | |
263 | u8 outbuf[2]; | |
264 | int ret; | |
265 | ||
266 | if (val >= (1 << 12) || val < 0) | |
267 | return -EINVAL; | |
268 | ||
269 | outbuf[0] = (val >> 8) & 0xf; | |
270 | outbuf[1] = val & 0xff; | |
271 | ||
272 | ret = i2c_master_send(data->client, outbuf, 2); | |
273 | if (ret < 0) | |
274 | return ret; | |
275 | else if (ret != 2) | |
276 | return -EIO; | |
277 | else | |
278 | return 0; | |
279 | } | |
280 | ||
281 | static int mcp4725_read_raw(struct iio_dev *indio_dev, | |
282 | struct iio_chan_spec const *chan, | |
283 | int *val, int *val2, long mask) | |
284 | { | |
285 | struct mcp4725_data *data = iio_priv(indio_dev); | |
cf35ad61 PM |
286 | |
287 | switch (mask) { | |
288 | case IIO_CHAN_INFO_RAW: | |
289 | *val = data->dac_value; | |
290 | return IIO_VAL_INT; | |
291 | case IIO_CHAN_INFO_SCALE: | |
b117f96f LPC |
292 | *val = data->vref_mv; |
293 | *val2 = 12; | |
294 | return IIO_VAL_FRACTIONAL_LOG2; | |
cf35ad61 PM |
295 | } |
296 | return -EINVAL; | |
297 | } | |
298 | ||
299 | static int mcp4725_write_raw(struct iio_dev *indio_dev, | |
300 | struct iio_chan_spec const *chan, | |
301 | int val, int val2, long mask) | |
302 | { | |
303 | struct mcp4725_data *data = iio_priv(indio_dev); | |
304 | int ret; | |
305 | ||
306 | switch (mask) { | |
307 | case IIO_CHAN_INFO_RAW: | |
308 | ret = mcp4725_set_value(indio_dev, val); | |
309 | data->dac_value = val; | |
310 | break; | |
311 | default: | |
312 | ret = -EINVAL; | |
313 | break; | |
314 | } | |
315 | ||
316 | return ret; | |
317 | } | |
318 | ||
319 | static const struct iio_info mcp4725_info = { | |
320 | .read_raw = mcp4725_read_raw, | |
321 | .write_raw = mcp4725_write_raw, | |
f17b77d6 | 322 | .attrs = &mcp4725_attribute_group, |
cf35ad61 PM |
323 | .driver_module = THIS_MODULE, |
324 | }; | |
325 | ||
fc52692c GKH |
326 | static int mcp4725_probe(struct i2c_client *client, |
327 | const struct i2c_device_id *id) | |
cf35ad61 PM |
328 | { |
329 | struct mcp4725_data *data; | |
330 | struct iio_dev *indio_dev; | |
331 | struct mcp4725_platform_data *platform_data = client->dev.platform_data; | |
332 | u8 inbuf[3]; | |
155f1b41 | 333 | u8 pd; |
cf35ad61 PM |
334 | int err; |
335 | ||
336 | if (!platform_data || !platform_data->vref_mv) { | |
337 | dev_err(&client->dev, "invalid platform data"); | |
b6ff86f3 | 338 | return -EINVAL; |
cf35ad61 PM |
339 | } |
340 | ||
b6ff86f3 PM |
341 | indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); |
342 | if (indio_dev == NULL) | |
343 | return -ENOMEM; | |
cf35ad61 PM |
344 | data = iio_priv(indio_dev); |
345 | i2c_set_clientdata(client, indio_dev); | |
346 | data->client = client; | |
347 | ||
348 | indio_dev->dev.parent = &client->dev; | |
97a249e9 | 349 | indio_dev->name = id->name; |
cf35ad61 | 350 | indio_dev->info = &mcp4725_info; |
35f73967 | 351 | indio_dev->channels = &mcp472x_channel[id->driver_data]; |
cf35ad61 PM |
352 | indio_dev->num_channels = 1; |
353 | indio_dev->modes = INDIO_DIRECT_MODE; | |
354 | ||
355 | data->vref_mv = platform_data->vref_mv; | |
356 | ||
357 | /* read current DAC value */ | |
358 | err = i2c_master_recv(client, inbuf, 3); | |
359 | if (err < 0) { | |
360 | dev_err(&client->dev, "failed to read DAC value"); | |
b6ff86f3 | 361 | return err; |
cf35ad61 | 362 | } |
155f1b41 PM |
363 | pd = (inbuf[0] >> 1) & 0x3; |
364 | data->powerdown = pd > 0 ? true : false; | |
35f73967 | 365 | data->powerdown_mode = pd ? pd - 1 : 2; /* largest register to gnd */ |
cf35ad61 PM |
366 | data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4); |
367 | ||
a9b68511 | 368 | return iio_device_register(indio_dev); |
cf35ad61 PM |
369 | } |
370 | ||
fc52692c | 371 | static int mcp4725_remove(struct i2c_client *client) |
cf35ad61 | 372 | { |
b6ff86f3 | 373 | iio_device_unregister(i2c_get_clientdata(client)); |
cf35ad61 PM |
374 | return 0; |
375 | } | |
376 | ||
377 | static const struct i2c_device_id mcp4725_id[] = { | |
35f73967 AM |
378 | { "mcp4725", MCP4725 }, |
379 | { "mcp4726", MCP4726 }, | |
cf35ad61 PM |
380 | { } |
381 | }; | |
382 | MODULE_DEVICE_TABLE(i2c, mcp4725_id); | |
383 | ||
384 | static struct i2c_driver mcp4725_driver = { | |
385 | .driver = { | |
386 | .name = MCP4725_DRV_NAME, | |
387 | .pm = MCP4725_PM_OPS, | |
388 | }, | |
389 | .probe = mcp4725_probe, | |
fc52692c | 390 | .remove = mcp4725_remove, |
cf35ad61 PM |
391 | .id_table = mcp4725_id, |
392 | }; | |
393 | module_i2c_driver(mcp4725_driver); | |
394 | ||
395 | MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>"); | |
35f73967 | 396 | MODULE_DESCRIPTION("MCP4725/6 12-bit DAC"); |
cf35ad61 | 397 | MODULE_LICENSE("GPL"); |