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68b14d7e LPC |
1 | /* |
2 | * Analog devices AD5764, AD5764R, AD5744, AD5744R quad-channel | |
3 | * Digital to Analog Converters driver | |
4 | * | |
5 | * Copyright 2011 Analog Devices Inc. | |
6 | * | |
7 | * Licensed under the GPL-2. | |
8 | */ | |
9 | ||
10 | #include <linux/device.h> | |
11 | #include <linux/err.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/kernel.h> | |
14 | #include <linux/spi/spi.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/sysfs.h> | |
17 | #include <linux/regulator/consumer.h> | |
18 | ||
06458e27 JC |
19 | #include <linux/iio/iio.h> |
20 | #include <linux/iio/sysfs.h> | |
68b14d7e LPC |
21 | |
22 | #define AD5764_REG_SF_NOP 0x0 | |
23 | #define AD5764_REG_SF_CONFIG 0x1 | |
24 | #define AD5764_REG_SF_CLEAR 0x4 | |
25 | #define AD5764_REG_SF_LOAD 0x5 | |
26 | #define AD5764_REG_DATA(x) ((2 << 3) | (x)) | |
27 | #define AD5764_REG_COARSE_GAIN(x) ((3 << 3) | (x)) | |
28 | #define AD5764_REG_FINE_GAIN(x) ((4 << 3) | (x)) | |
29 | #define AD5764_REG_OFFSET(x) ((5 << 3) | (x)) | |
30 | ||
31 | #define AD5764_NUM_CHANNELS 4 | |
32 | ||
33 | /** | |
34 | * struct ad5764_chip_info - chip specific information | |
35 | * @int_vref: Value of the internal reference voltage in uV - 0 if external | |
36 | * reference voltage is used | |
37 | * @channel channel specification | |
38 | */ | |
39 | ||
40 | struct ad5764_chip_info { | |
41 | unsigned long int_vref; | |
42 | const struct iio_chan_spec *channels; | |
43 | }; | |
44 | ||
45 | /** | |
46 | * struct ad5764_state - driver instance specific data | |
47 | * @spi: spi_device | |
48 | * @chip_info: chip info | |
49 | * @vref_reg: vref supply regulators | |
50 | * @data: spi transfer buffers | |
51 | */ | |
52 | ||
53 | struct ad5764_state { | |
54 | struct spi_device *spi; | |
55 | const struct ad5764_chip_info *chip_info; | |
56 | struct regulator_bulk_data vref_reg[2]; | |
57 | ||
58 | /* | |
59 | * DMA (thus cache coherency maintenance) requires the | |
60 | * transfer buffers to live in their own cache lines. | |
61 | */ | |
62 | union { | |
63 | __be32 d32; | |
64 | u8 d8[4]; | |
65 | } data[2] ____cacheline_aligned; | |
66 | }; | |
67 | ||
68 | enum ad5764_type { | |
69 | ID_AD5744, | |
70 | ID_AD5744R, | |
71 | ID_AD5764, | |
72 | ID_AD5764R, | |
73 | }; | |
74 | ||
75 | #define AD5764_CHANNEL(_chan, _bits) { \ | |
76 | .type = IIO_VOLTAGE, \ | |
77 | .indexed = 1, \ | |
78 | .output = 1, \ | |
79 | .channel = (_chan), \ | |
80 | .address = (_chan), \ | |
09f4eb40 JC |
81 | .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \ |
82 | IIO_CHAN_INFO_OFFSET_SHARED_BIT | \ | |
68b14d7e LPC |
83 | IIO_CHAN_INFO_SCALE_SEPARATE_BIT | \ |
84 | IIO_CHAN_INFO_CALIBSCALE_SEPARATE_BIT | \ | |
85 | IIO_CHAN_INFO_CALIBBIAS_SEPARATE_BIT, \ | |
86 | .scan_type = IIO_ST('u', (_bits), 16, 16 - (_bits)) \ | |
87 | } | |
88 | ||
89 | #define DECLARE_AD5764_CHANNELS(_name, _bits) \ | |
90 | const struct iio_chan_spec _name##_channels[] = { \ | |
91 | AD5764_CHANNEL(0, (_bits)), \ | |
92 | AD5764_CHANNEL(1, (_bits)), \ | |
93 | AD5764_CHANNEL(2, (_bits)), \ | |
94 | AD5764_CHANNEL(3, (_bits)), \ | |
95 | }; | |
96 | ||
97 | static DECLARE_AD5764_CHANNELS(ad5764, 16); | |
98 | static DECLARE_AD5764_CHANNELS(ad5744, 14); | |
99 | ||
100 | static const struct ad5764_chip_info ad5764_chip_infos[] = { | |
101 | [ID_AD5744] = { | |
102 | .int_vref = 0, | |
103 | .channels = ad5744_channels, | |
104 | }, | |
105 | [ID_AD5744R] = { | |
106 | .int_vref = 5000000, | |
107 | .channels = ad5744_channels, | |
108 | }, | |
109 | [ID_AD5764] = { | |
110 | .int_vref = 0, | |
111 | .channels = ad5764_channels, | |
112 | }, | |
113 | [ID_AD5764R] = { | |
114 | .int_vref = 5000000, | |
115 | .channels = ad5764_channels, | |
116 | }, | |
117 | }; | |
118 | ||
119 | static int ad5764_write(struct iio_dev *indio_dev, unsigned int reg, | |
120 | unsigned int val) | |
121 | { | |
122 | struct ad5764_state *st = iio_priv(indio_dev); | |
123 | int ret; | |
124 | ||
125 | mutex_lock(&indio_dev->mlock); | |
126 | st->data[0].d32 = cpu_to_be32((reg << 16) | val); | |
127 | ||
128 | ret = spi_write(st->spi, &st->data[0].d8[1], 3); | |
129 | mutex_unlock(&indio_dev->mlock); | |
130 | ||
131 | return ret; | |
132 | } | |
133 | ||
134 | static int ad5764_read(struct iio_dev *indio_dev, unsigned int reg, | |
135 | unsigned int *val) | |
136 | { | |
137 | struct ad5764_state *st = iio_priv(indio_dev); | |
138 | struct spi_message m; | |
139 | int ret; | |
140 | struct spi_transfer t[] = { | |
141 | { | |
142 | .tx_buf = &st->data[0].d8[1], | |
143 | .len = 3, | |
144 | .cs_change = 1, | |
145 | }, { | |
146 | .rx_buf = &st->data[1].d8[1], | |
147 | .len = 3, | |
148 | }, | |
149 | }; | |
150 | ||
151 | spi_message_init(&m); | |
152 | spi_message_add_tail(&t[0], &m); | |
153 | spi_message_add_tail(&t[1], &m); | |
154 | ||
155 | mutex_lock(&indio_dev->mlock); | |
156 | ||
157 | st->data[0].d32 = cpu_to_be32((1 << 23) | (reg << 16)); | |
158 | ||
159 | ret = spi_sync(st->spi, &m); | |
160 | if (ret >= 0) | |
161 | *val = be32_to_cpu(st->data[1].d32) & 0xffff; | |
162 | ||
163 | mutex_unlock(&indio_dev->mlock); | |
164 | ||
165 | return ret; | |
166 | } | |
167 | ||
168 | static int ad5764_chan_info_to_reg(struct iio_chan_spec const *chan, long info) | |
169 | { | |
170 | switch (info) { | |
171 | case 0: | |
172 | return AD5764_REG_DATA(chan->address); | |
173 | case IIO_CHAN_INFO_CALIBBIAS: | |
174 | return AD5764_REG_OFFSET(chan->address); | |
175 | case IIO_CHAN_INFO_CALIBSCALE: | |
176 | return AD5764_REG_FINE_GAIN(chan->address); | |
177 | default: | |
178 | break; | |
179 | } | |
180 | ||
181 | return 0; | |
182 | } | |
183 | ||
184 | static int ad5764_write_raw(struct iio_dev *indio_dev, | |
185 | struct iio_chan_spec const *chan, int val, int val2, long info) | |
186 | { | |
187 | const int max_val = (1 << chan->scan_type.realbits); | |
188 | unsigned int reg; | |
189 | ||
190 | switch (info) { | |
09f4eb40 | 191 | case IIO_CHAN_INFO_RAW: |
68b14d7e LPC |
192 | if (val >= max_val || val < 0) |
193 | return -EINVAL; | |
194 | val <<= chan->scan_type.shift; | |
195 | break; | |
196 | case IIO_CHAN_INFO_CALIBBIAS: | |
197 | if (val >= 128 || val < -128) | |
198 | return -EINVAL; | |
199 | break; | |
200 | case IIO_CHAN_INFO_CALIBSCALE: | |
201 | if (val >= 32 || val < -32) | |
202 | return -EINVAL; | |
203 | break; | |
204 | default: | |
205 | return -EINVAL; | |
206 | } | |
207 | ||
208 | reg = ad5764_chan_info_to_reg(chan, info); | |
209 | return ad5764_write(indio_dev, reg, (u16)val); | |
210 | } | |
211 | ||
212 | static int ad5764_get_channel_vref(struct ad5764_state *st, | |
213 | unsigned int channel) | |
214 | { | |
215 | if (st->chip_info->int_vref) | |
216 | return st->chip_info->int_vref; | |
217 | else | |
218 | return regulator_get_voltage(st->vref_reg[channel / 2].consumer); | |
219 | } | |
220 | ||
221 | static int ad5764_read_raw(struct iio_dev *indio_dev, | |
222 | struct iio_chan_spec const *chan, int *val, int *val2, long info) | |
223 | { | |
224 | struct ad5764_state *st = iio_priv(indio_dev); | |
225 | unsigned long scale_uv; | |
226 | unsigned int reg; | |
227 | int vref; | |
228 | int ret; | |
229 | ||
230 | switch (info) { | |
09f4eb40 | 231 | case IIO_CHAN_INFO_RAW: |
68b14d7e LPC |
232 | reg = AD5764_REG_DATA(chan->address); |
233 | ret = ad5764_read(indio_dev, reg, val); | |
234 | if (ret < 0) | |
235 | return ret; | |
236 | *val >>= chan->scan_type.shift; | |
237 | return IIO_VAL_INT; | |
238 | case IIO_CHAN_INFO_CALIBBIAS: | |
239 | reg = AD5764_REG_OFFSET(chan->address); | |
240 | ret = ad5764_read(indio_dev, reg, val); | |
241 | if (ret < 0) | |
242 | return ret; | |
243 | *val = sign_extend32(*val, 7); | |
244 | return IIO_VAL_INT; | |
245 | case IIO_CHAN_INFO_CALIBSCALE: | |
246 | reg = AD5764_REG_FINE_GAIN(chan->address); | |
247 | ret = ad5764_read(indio_dev, reg, val); | |
248 | if (ret < 0) | |
249 | return ret; | |
250 | *val = sign_extend32(*val, 5); | |
251 | return IIO_VAL_INT; | |
252 | case IIO_CHAN_INFO_SCALE: | |
253 | /* vout = 4 * vref + ((dac_code / 65535) - 0.5) */ | |
254 | vref = ad5764_get_channel_vref(st, chan->channel); | |
255 | if (vref < 0) | |
256 | return vref; | |
257 | ||
258 | scale_uv = (vref * 4 * 100) >> chan->scan_type.realbits; | |
259 | *val = scale_uv / 100000; | |
260 | *val2 = (scale_uv % 100000) * 10; | |
261 | return IIO_VAL_INT_PLUS_MICRO; | |
262 | case IIO_CHAN_INFO_OFFSET: | |
263 | *val = -(1 << chan->scan_type.realbits) / 2; | |
264 | return IIO_VAL_INT; | |
265 | } | |
266 | ||
267 | return -EINVAL; | |
268 | } | |
269 | ||
270 | static const struct iio_info ad5764_info = { | |
271 | .read_raw = ad5764_read_raw, | |
272 | .write_raw = ad5764_write_raw, | |
273 | .driver_module = THIS_MODULE, | |
274 | }; | |
275 | ||
276 | static int __devinit ad5764_probe(struct spi_device *spi) | |
277 | { | |
278 | enum ad5764_type type = spi_get_device_id(spi)->driver_data; | |
279 | struct iio_dev *indio_dev; | |
280 | struct ad5764_state *st; | |
281 | int ret; | |
282 | ||
7cbb7537 | 283 | indio_dev = iio_device_alloc(sizeof(*st)); |
68b14d7e LPC |
284 | if (indio_dev == NULL) { |
285 | dev_err(&spi->dev, "Failed to allocate iio device\n"); | |
286 | return -ENOMEM; | |
287 | } | |
288 | ||
289 | st = iio_priv(indio_dev); | |
290 | spi_set_drvdata(spi, indio_dev); | |
291 | ||
292 | st->spi = spi; | |
293 | st->chip_info = &ad5764_chip_infos[type]; | |
294 | ||
295 | indio_dev->dev.parent = &spi->dev; | |
296 | indio_dev->name = spi_get_device_id(spi)->name; | |
297 | indio_dev->info = &ad5764_info; | |
298 | indio_dev->modes = INDIO_DIRECT_MODE; | |
299 | indio_dev->num_channels = AD5764_NUM_CHANNELS; | |
300 | indio_dev->channels = st->chip_info->channels; | |
301 | ||
302 | if (st->chip_info->int_vref == 0) { | |
303 | st->vref_reg[0].supply = "vrefAB"; | |
304 | st->vref_reg[1].supply = "vrefCD"; | |
305 | ||
306 | ret = regulator_bulk_get(&st->spi->dev, | |
307 | ARRAY_SIZE(st->vref_reg), st->vref_reg); | |
308 | if (ret) { | |
309 | dev_err(&spi->dev, "Failed to request vref regulators: %d\n", | |
310 | ret); | |
311 | goto error_free; | |
312 | } | |
313 | ||
314 | ret = regulator_bulk_enable(ARRAY_SIZE(st->vref_reg), | |
315 | st->vref_reg); | |
316 | if (ret) { | |
317 | dev_err(&spi->dev, "Failed to enable vref regulators: %d\n", | |
318 | ret); | |
319 | goto error_free_reg; | |
320 | } | |
321 | } | |
322 | ||
323 | ret = iio_device_register(indio_dev); | |
324 | if (ret) { | |
325 | dev_err(&spi->dev, "Failed to register iio device: %d\n", ret); | |
326 | goto error_disable_reg; | |
327 | } | |
328 | ||
329 | return 0; | |
330 | ||
331 | error_disable_reg: | |
332 | if (st->chip_info->int_vref == 0) | |
333 | regulator_bulk_disable(ARRAY_SIZE(st->vref_reg), st->vref_reg); | |
334 | error_free_reg: | |
335 | if (st->chip_info->int_vref == 0) | |
336 | regulator_bulk_free(ARRAY_SIZE(st->vref_reg), st->vref_reg); | |
337 | error_free: | |
7cbb7537 | 338 | iio_device_free(indio_dev); |
68b14d7e LPC |
339 | |
340 | return ret; | |
341 | } | |
342 | ||
343 | static int __devexit ad5764_remove(struct spi_device *spi) | |
344 | { | |
345 | struct iio_dev *indio_dev = spi_get_drvdata(spi); | |
346 | struct ad5764_state *st = iio_priv(indio_dev); | |
347 | ||
348 | iio_device_unregister(indio_dev); | |
349 | ||
350 | if (st->chip_info->int_vref == 0) { | |
351 | regulator_bulk_disable(ARRAY_SIZE(st->vref_reg), st->vref_reg); | |
352 | regulator_bulk_free(ARRAY_SIZE(st->vref_reg), st->vref_reg); | |
353 | } | |
354 | ||
7cbb7537 | 355 | iio_device_free(indio_dev); |
68b14d7e LPC |
356 | |
357 | return 0; | |
358 | } | |
359 | ||
360 | static const struct spi_device_id ad5764_ids[] = { | |
361 | { "ad5744", ID_AD5744 }, | |
362 | { "ad5744r", ID_AD5744R }, | |
363 | { "ad5764", ID_AD5764 }, | |
364 | { "ad5764r", ID_AD5764R }, | |
365 | { } | |
366 | }; | |
367 | MODULE_DEVICE_TABLE(spi, ad5764_ids); | |
368 | ||
369 | static struct spi_driver ad5764_driver = { | |
370 | .driver = { | |
371 | .name = "ad5764", | |
372 | .owner = THIS_MODULE, | |
373 | }, | |
374 | .probe = ad5764_probe, | |
375 | .remove = __devexit_p(ad5764_remove), | |
376 | .id_table = ad5764_ids, | |
377 | }; | |
519ff1d2 | 378 | module_spi_driver(ad5764_driver); |
68b14d7e LPC |
379 | |
380 | MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); | |
381 | MODULE_DESCRIPTION("Analog Devices AD5744/AD5744R/AD5764/AD5764R DAC"); | |
382 | MODULE_LICENSE("GPL v2"); |