1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * AD5721, AD5721R, AD5761, AD5761R, Voltage Output Digital to Analog Converter |
4 | * |
5 | * Copyright 2016 Qtechnology A/S |
6 | * 2016 Ricardo Ribalda <ribalda@kernel.org> |
7 | */ |
8 | #include <linux/kernel.h> |
9 | #include <linux/module.h> |
10 | #include <linux/spi/spi.h> |
11 | #include <linux/bitops.h> |
12 | #include <linux/iio/iio.h> |
13 | #include <linux/iio/sysfs.h> |
14 | #include <linux/regulator/consumer.h> |
15 | #include <linux/platform_data/ad5761.h> |
16 | |
17 | #define AD5761_ADDR(addr) ((addr & 0xf) << 16) |
18 | #define AD5761_ADDR_NOOP 0x0 |
19 | #define AD5761_ADDR_DAC_WRITE 0x3 |
20 | #define AD5761_ADDR_CTRL_WRITE_REG 0x4 |
21 | #define AD5761_ADDR_SW_DATA_RESET 0x7 |
22 | #define AD5761_ADDR_DAC_READ 0xb |
23 | #define AD5761_ADDR_CTRL_READ_REG 0xc |
24 | #define AD5761_ADDR_SW_FULL_RESET 0xf |
25 | |
26 | #define AD5761_CTRL_USE_INTVREF BIT(5) |
27 | #define AD5761_CTRL_ETS BIT(6) |
28 | |
29 | /** |
30 | * struct ad5761_chip_info - chip specific information |
31 | * @int_vref: Value of the internal reference voltage in mV - 0 if external |
32 | * reference voltage is used |
33 | * @channel: channel specification |
34 | */ |
35 | |
36 | struct ad5761_chip_info { |
37 | unsigned long int_vref; |
38 | const struct iio_chan_spec channel; |
39 | }; |
40 | |
41 | struct ad5761_range_params { |
42 | int m; |
43 | int c; |
44 | }; |
45 | |
46 | enum ad5761_supported_device_ids { |
47 | ID_AD5721, |
48 | ID_AD5721R, |
49 | ID_AD5761, |
50 | ID_AD5761R, |
51 | }; |
52 | |
53 | /** |
54 | * struct ad5761_state - driver instance specific data |
55 | * @spi: spi_device |
56 | * @vref_reg: reference voltage regulator |
57 | * @use_intref: true when the internal voltage reference is used |
58 | * @vref: actual voltage reference in mVolts |
59 | * @range: output range mode used |
60 | * @lock: lock to protect the data buffer during SPI ops |
61 | * @data: cache aligned spi buffer |
62 | */ |
63 | struct ad5761_state { |
64 | struct spi_device *spi; |
65 | struct regulator *vref_reg; |
66 | struct mutex lock; |
67 | |
68 | bool use_intref; |
69 | int vref; |
70 | enum ad5761_voltage_range range; |
71 | |
72 | /* |
73 | * DMA (thus cache coherency maintenance) may require the |
74 | * transfer buffers to live in their own cache lines. |
75 | */ |
76 | union { |
77 | __be32 d32; |
78 | u8 d8[4]; |
79 | } data[3] __aligned(IIO_DMA_MINALIGN); |
80 | }; |
81 | |
82 | static const struct ad5761_range_params ad5761_range_params[] = { |
83 | [AD5761_VOLTAGE_RANGE_M10V_10V] = { |
84 | .m = 80, |
85 | .c = 40, |
86 | }, |
87 | [AD5761_VOLTAGE_RANGE_0V_10V] = { |
88 | .m = 40, |
89 | .c = 0, |
90 | }, |
91 | [AD5761_VOLTAGE_RANGE_M5V_5V] = { |
92 | .m = 40, |
93 | .c = 20, |
94 | }, |
95 | [AD5761_VOLTAGE_RANGE_0V_5V] = { |
96 | .m = 20, |
97 | .c = 0, |
98 | }, |
99 | [AD5761_VOLTAGE_RANGE_M2V5_7V5] = { |
100 | .m = 40, |
101 | .c = 10, |
102 | }, |
103 | [AD5761_VOLTAGE_RANGE_M3V_3V] = { |
104 | .m = 24, |
105 | .c = 12, |
106 | }, |
107 | [AD5761_VOLTAGE_RANGE_0V_16V] = { |
108 | .m = 64, |
109 | .c = 0, |
110 | }, |
111 | [AD5761_VOLTAGE_RANGE_0V_20V] = { |
112 | .m = 80, |
113 | .c = 0, |
114 | }, |
115 | }; |
116 | |
117 | static int _ad5761_spi_write(struct ad5761_state *st, u8 addr, u16 val) |
118 | { |
119 | st->data[0].d32 = cpu_to_be32(AD5761_ADDR(addr) | val); |
120 | |
121 | return spi_write(spi: st->spi, buf: &st->data[0].d8[1], len: 3); |
122 | } |
123 | |
124 | static int ad5761_spi_write(struct iio_dev *indio_dev, u8 addr, u16 val) |
125 | { |
126 | struct ad5761_state *st = iio_priv(indio_dev); |
127 | int ret; |
128 | |
129 | mutex_lock(&st->lock); |
130 | ret = _ad5761_spi_write(st, addr, val); |
131 | mutex_unlock(lock: &st->lock); |
132 | |
133 | return ret; |
134 | } |
135 | |
136 | static int _ad5761_spi_read(struct ad5761_state *st, u8 addr, u16 *val) |
137 | { |
138 | int ret; |
139 | struct spi_transfer xfers[] = { |
140 | { |
141 | .tx_buf = &st->data[0].d8[1], |
142 | .bits_per_word = 8, |
143 | .len = 3, |
144 | .cs_change = true, |
145 | }, { |
146 | .tx_buf = &st->data[1].d8[1], |
147 | .rx_buf = &st->data[2].d8[1], |
148 | .bits_per_word = 8, |
149 | .len = 3, |
150 | }, |
151 | }; |
152 | |
153 | st->data[0].d32 = cpu_to_be32(AD5761_ADDR(addr)); |
154 | st->data[1].d32 = cpu_to_be32(AD5761_ADDR(AD5761_ADDR_NOOP)); |
155 | |
156 | ret = spi_sync_transfer(spi: st->spi, xfers, ARRAY_SIZE(xfers)); |
157 | |
158 | *val = be32_to_cpu(st->data[2].d32); |
159 | |
160 | return ret; |
161 | } |
162 | |
163 | static int ad5761_spi_read(struct iio_dev *indio_dev, u8 addr, u16 *val) |
164 | { |
165 | struct ad5761_state *st = iio_priv(indio_dev); |
166 | int ret; |
167 | |
168 | mutex_lock(&st->lock); |
169 | ret = _ad5761_spi_read(st, addr, val); |
170 | mutex_unlock(lock: &st->lock); |
171 | |
172 | return ret; |
173 | } |
174 | |
175 | static int ad5761_spi_set_range(struct ad5761_state *st, |
176 | enum ad5761_voltage_range range) |
177 | { |
178 | u16 aux; |
179 | int ret; |
180 | |
181 | aux = (range & 0x7) | AD5761_CTRL_ETS; |
182 | |
183 | if (st->use_intref) |
184 | aux |= AD5761_CTRL_USE_INTVREF; |
185 | |
186 | ret = _ad5761_spi_write(st, AD5761_ADDR_SW_FULL_RESET, val: 0); |
187 | if (ret) |
188 | return ret; |
189 | |
190 | ret = _ad5761_spi_write(st, AD5761_ADDR_CTRL_WRITE_REG, val: aux); |
191 | if (ret) |
192 | return ret; |
193 | |
194 | st->range = range; |
195 | |
196 | return 0; |
197 | } |
198 | |
199 | static int ad5761_read_raw(struct iio_dev *indio_dev, |
200 | struct iio_chan_spec const *chan, |
201 | int *val, |
202 | int *val2, |
203 | long mask) |
204 | { |
205 | struct ad5761_state *st; |
206 | int ret; |
207 | u16 aux; |
208 | |
209 | switch (mask) { |
210 | case IIO_CHAN_INFO_RAW: |
211 | ret = ad5761_spi_read(indio_dev, AD5761_ADDR_DAC_READ, val: &aux); |
212 | if (ret) |
213 | return ret; |
214 | *val = aux >> chan->scan_type.shift; |
215 | return IIO_VAL_INT; |
216 | case IIO_CHAN_INFO_SCALE: |
217 | st = iio_priv(indio_dev); |
218 | *val = st->vref * ad5761_range_params[st->range].m; |
219 | *val /= 10; |
220 | *val2 = chan->scan_type.realbits; |
221 | return IIO_VAL_FRACTIONAL_LOG2; |
222 | case IIO_CHAN_INFO_OFFSET: |
223 | st = iio_priv(indio_dev); |
224 | *val = -(1 << chan->scan_type.realbits); |
225 | *val *= ad5761_range_params[st->range].c; |
226 | *val /= ad5761_range_params[st->range].m; |
227 | return IIO_VAL_INT; |
228 | default: |
229 | return -EINVAL; |
230 | } |
231 | } |
232 | |
233 | static int ad5761_write_raw(struct iio_dev *indio_dev, |
234 | struct iio_chan_spec const *chan, |
235 | int val, |
236 | int val2, |
237 | long mask) |
238 | { |
239 | u16 aux; |
240 | |
241 | if (mask != IIO_CHAN_INFO_RAW) |
242 | return -EINVAL; |
243 | |
244 | if (val2 || (val << chan->scan_type.shift) > 0xffff || val < 0) |
245 | return -EINVAL; |
246 | |
247 | aux = val << chan->scan_type.shift; |
248 | |
249 | return ad5761_spi_write(indio_dev, AD5761_ADDR_DAC_WRITE, val: aux); |
250 | } |
251 | |
252 | static const struct iio_info ad5761_info = { |
253 | .read_raw = &ad5761_read_raw, |
254 | .write_raw = &ad5761_write_raw, |
255 | }; |
256 | |
257 | #define AD5761_CHAN(_bits) { \ |
258 | .type = IIO_VOLTAGE, \ |
259 | .output = 1, \ |
260 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
261 | .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ |
262 | BIT(IIO_CHAN_INFO_OFFSET), \ |
263 | .scan_type = { \ |
264 | .sign = 'u', \ |
265 | .realbits = (_bits), \ |
266 | .storagebits = 16, \ |
267 | .shift = 16 - (_bits), \ |
268 | }, \ |
269 | } |
270 | |
271 | static const struct ad5761_chip_info ad5761_chip_infos[] = { |
272 | [ID_AD5721] = { |
273 | .int_vref = 0, |
274 | .channel = AD5761_CHAN(12), |
275 | }, |
276 | [ID_AD5721R] = { |
277 | .int_vref = 2500, |
278 | .channel = AD5761_CHAN(12), |
279 | }, |
280 | [ID_AD5761] = { |
281 | .int_vref = 0, |
282 | .channel = AD5761_CHAN(16), |
283 | }, |
284 | [ID_AD5761R] = { |
285 | .int_vref = 2500, |
286 | .channel = AD5761_CHAN(16), |
287 | }, |
288 | }; |
289 | |
290 | static int ad5761_get_vref(struct ad5761_state *st, |
291 | const struct ad5761_chip_info *chip_info) |
292 | { |
293 | int ret; |
294 | |
295 | st->vref_reg = devm_regulator_get_optional(dev: &st->spi->dev, id: "vref" ); |
296 | if (PTR_ERR(ptr: st->vref_reg) == -ENODEV) { |
297 | /* Use Internal regulator */ |
298 | if (!chip_info->int_vref) { |
299 | dev_err(&st->spi->dev, |
300 | "Voltage reference not found\n" ); |
301 | return -EIO; |
302 | } |
303 | |
304 | st->use_intref = true; |
305 | st->vref = chip_info->int_vref; |
306 | return 0; |
307 | } |
308 | |
309 | if (IS_ERR(ptr: st->vref_reg)) { |
310 | dev_err(&st->spi->dev, |
311 | "Error getting voltage reference regulator\n" ); |
312 | return PTR_ERR(ptr: st->vref_reg); |
313 | } |
314 | |
315 | ret = regulator_enable(regulator: st->vref_reg); |
316 | if (ret) { |
317 | dev_err(&st->spi->dev, |
318 | "Failed to enable voltage reference\n" ); |
319 | return ret; |
320 | } |
321 | |
322 | ret = regulator_get_voltage(regulator: st->vref_reg); |
323 | if (ret < 0) { |
324 | dev_err(&st->spi->dev, |
325 | "Failed to get voltage reference value\n" ); |
326 | goto disable_regulator_vref; |
327 | } |
328 | |
329 | if (ret < 2000000 || ret > 3000000) { |
330 | dev_warn(&st->spi->dev, |
331 | "Invalid external voltage ref. value %d uV\n" , ret); |
332 | ret = -EIO; |
333 | goto disable_regulator_vref; |
334 | } |
335 | |
336 | st->vref = ret / 1000; |
337 | st->use_intref = false; |
338 | |
339 | return 0; |
340 | |
341 | disable_regulator_vref: |
342 | regulator_disable(regulator: st->vref_reg); |
343 | st->vref_reg = NULL; |
344 | return ret; |
345 | } |
346 | |
347 | static int ad5761_probe(struct spi_device *spi) |
348 | { |
349 | struct iio_dev *iio_dev; |
350 | struct ad5761_state *st; |
351 | int ret; |
352 | const struct ad5761_chip_info *chip_info = |
353 | &ad5761_chip_infos[spi_get_device_id(sdev: spi)->driver_data]; |
354 | enum ad5761_voltage_range voltage_range = AD5761_VOLTAGE_RANGE_0V_5V; |
355 | struct ad5761_platform_data *pdata = dev_get_platdata(dev: &spi->dev); |
356 | |
357 | iio_dev = devm_iio_device_alloc(parent: &spi->dev, sizeof_priv: sizeof(*st)); |
358 | if (!iio_dev) |
359 | return -ENOMEM; |
360 | |
361 | st = iio_priv(indio_dev: iio_dev); |
362 | |
363 | st->spi = spi; |
364 | spi_set_drvdata(spi, data: iio_dev); |
365 | |
366 | ret = ad5761_get_vref(st, chip_info); |
367 | if (ret) |
368 | return ret; |
369 | |
370 | if (pdata) |
371 | voltage_range = pdata->voltage_range; |
372 | |
373 | mutex_init(&st->lock); |
374 | |
375 | ret = ad5761_spi_set_range(st, range: voltage_range); |
376 | if (ret) |
377 | goto disable_regulator_err; |
378 | |
379 | iio_dev->info = &ad5761_info; |
380 | iio_dev->modes = INDIO_DIRECT_MODE; |
381 | iio_dev->channels = &chip_info->channel; |
382 | iio_dev->num_channels = 1; |
383 | iio_dev->name = spi_get_device_id(sdev: st->spi)->name; |
384 | ret = iio_device_register(iio_dev); |
385 | if (ret) |
386 | goto disable_regulator_err; |
387 | |
388 | return 0; |
389 | |
390 | disable_regulator_err: |
391 | if (!IS_ERR_OR_NULL(ptr: st->vref_reg)) |
392 | regulator_disable(regulator: st->vref_reg); |
393 | |
394 | return ret; |
395 | } |
396 | |
397 | static void ad5761_remove(struct spi_device *spi) |
398 | { |
399 | struct iio_dev *iio_dev = spi_get_drvdata(spi); |
400 | struct ad5761_state *st = iio_priv(indio_dev: iio_dev); |
401 | |
402 | iio_device_unregister(indio_dev: iio_dev); |
403 | |
404 | if (!IS_ERR_OR_NULL(ptr: st->vref_reg)) |
405 | regulator_disable(regulator: st->vref_reg); |
406 | } |
407 | |
408 | static const struct spi_device_id ad5761_id[] = { |
409 | {"ad5721" , ID_AD5721}, |
410 | {"ad5721r" , ID_AD5721R}, |
411 | {"ad5761" , ID_AD5761}, |
412 | {"ad5761r" , ID_AD5761R}, |
413 | {} |
414 | }; |
415 | MODULE_DEVICE_TABLE(spi, ad5761_id); |
416 | |
417 | static struct spi_driver ad5761_driver = { |
418 | .driver = { |
419 | .name = "ad5761" , |
420 | }, |
421 | .probe = ad5761_probe, |
422 | .remove = ad5761_remove, |
423 | .id_table = ad5761_id, |
424 | }; |
425 | module_spi_driver(ad5761_driver); |
426 | |
427 | MODULE_AUTHOR("Ricardo Ribalda <ribalda@kernel.org>" ); |
428 | MODULE_DESCRIPTION("Analog Devices AD5721, AD5721R, AD5761, AD5761R driver" ); |
429 | MODULE_LICENSE("GPL v2" ); |
430 | |