1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * IIO driver for MCP356X/MCP356XR and MCP346X/MCP346XR series ADC chip family
4 *
5 * Copyright (C) 2022-2023 Microchip Technology Inc. and its subsidiaries
6 *
7 * Author: Marius Cristea <marius.cristea@microchip.com>
8 *
9 * Datasheet for MCP3561, MCP3562, MCP3564 can be found here:
10 * https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/MCP3561-2-4-Family-Data-Sheet-DS20006181C.pdf
11 * Datasheet for MCP3561R, MCP3562R, MCP3564R can be found here:
12 * https://ww1.microchip.com/downloads/aemDocuments/documents/APID/ProductDocuments/DataSheets/MCP3561_2_4R-Data-Sheet-DS200006391C.pdf
13 * Datasheet for MCP3461, MCP3462, MCP3464 can be found here:
14 * https://ww1.microchip.com/downloads/aemDocuments/documents/APID/ProductDocuments/DataSheets/MCP3461-2-4-Two-Four-Eight-Channel-153.6-ksps-Low-Noise-16-Bit-Delta-Sigma-ADC-Data-Sheet-20006180D.pdf
15 * Datasheet for MCP3461R, MCP3462R, MCP3464R can be found here:
16 * https://ww1.microchip.com/downloads/aemDocuments/documents/APID/ProductDocuments/DataSheets/MCP3461-2-4R-Family-Data-Sheet-DS20006404C.pdf
17 */
18
19#include <linux/bitfield.h>
20#include <linux/iopoll.h>
21#include <linux/regulator/consumer.h>
22#include <linux/spi/spi.h>
23#include <linux/units.h>
24#include <linux/util_macros.h>
25
26#include <linux/iio/iio.h>
27#include <linux/iio/sysfs.h>
28
29#define MCP3564_ADCDATA_REG 0x00
30
31#define MCP3564_CONFIG0_REG 0x01
32#define MCP3564_CONFIG0_ADC_MODE_MASK GENMASK(1, 0)
33/* Current Source/Sink Selection Bits for Sensor Bias */
34#define MCP3564_CONFIG0_CS_SEL_MASK GENMASK(3, 2)
35/* Internal clock is selected and AMCLK is present on the analog master clock output pin */
36#define MCP3564_CONFIG0_USE_INT_CLK_OUTPUT_EN 0x03
37/* Internal clock is selected and no clock output is present on the CLK pin */
38#define MCP3564_CONFIG0_USE_INT_CLK 0x02
39/* External digital clock */
40#define MCP3564_CONFIG0_USE_EXT_CLK 0x01
41/* External digital clock (default) */
42#define MCP3564_CONFIG0_USE_EXT_CLK_DEFAULT 0x00
43#define MCP3564_CONFIG0_CLK_SEL_MASK GENMASK(5, 4)
44#define MCP3456_CONFIG0_BIT6_DEFAULT BIT(6)
45#define MCP3456_CONFIG0_VREF_MASK BIT(7)
46
47#define MCP3564_CONFIG1_REG 0x02
48#define MCP3564_CONFIG1_OVERSPL_RATIO_MASK GENMASK(5, 2)
49
50#define MCP3564_CONFIG2_REG 0x03
51#define MCP3564_CONFIG2_AZ_REF_MASK BIT(1)
52#define MCP3564_CONFIG2_AZ_MUX_MASK BIT(2)
53
54#define MCP3564_CONFIG2_HARDWARE_GAIN_MASK GENMASK(5, 3)
55#define MCP3564_DEFAULT_HARDWARE_GAIN 0x01
56#define MCP3564_CONFIG2_BOOST_CURRENT_MASK GENMASK(7, 6)
57
58#define MCP3564_CONFIG3_REG 0x04
59#define MCP3464_CONFIG3_EN_GAINCAL_MASK BIT(0)
60#define MCP3464_CONFIG3_EN_OFFCAL_MASK BIT(1)
61#define MCP3464_CONFIG3_EN_CRCCOM_MASK BIT(2)
62#define MCP3464_CONFIG3_CRC_FORMAT_MASK BIT(3)
63/*
64 * ADC Output Data Format 32-bit (25-bit right justified data + Channel ID):
65 * CHID[3:0] + SGN extension (4 bits) + 24-bit ADC data.
66 * It allows overrange with the SGN extension.
67 */
68#define MCP3464_CONFIG3_DATA_FMT_32B_WITH_CH_ID 3
69/*
70 * ADC Output Data Format 32-bit (25-bit right justified data):
71 * SGN extension (8-bit) + 24-bit ADC data.
72 * It allows overrange with the SGN extension.
73 */
74#define MCP3464_CONFIG3_DATA_FMT_32B_SGN_EXT 2
75/*
76 * ADC Output Data Format 32-bit (24-bit left justified data):
77 * 24-bit ADC data + 0x00 (8-bit).
78 * It does not allow overrange (ADC code locked to 0xFFFFFF or 0x800000).
79 */
80#define MCP3464_CONFIG3_DATA_FMT_32B_LEFT_JUSTIFIED 1
81/*
82 * ADC Output Data Format 24-bit (default ADC coding):
83 * 24-bit ADC data.
84 * It does not allow overrange (ADC code locked to 0xFFFFFF or 0x800000).
85 */
86#define MCP3464_CONFIG3_DATA_FMT_24B 0
87#define MCP3464_CONFIG3_DATA_FORMAT_MASK GENMASK(5, 4)
88
89/* Continuous Conversion mode or continuous conversion cycle in SCAN mode. */
90#define MCP3464_CONFIG3_CONV_MODE_CONTINUOUS 3
91/*
92 * One-shot conversion or one-shot cycle in SCAN mode. It sets ADC_MODE[1:0] to ‘10’
93 * (standby) at the end of the conversion or at the end of the conversion cycle in SCAN mode.
94 */
95#define MCP3464_CONFIG3_CONV_MODE_ONE_SHOT_STANDBY 2
96/*
97 * One-shot conversion or one-shot cycle in SCAN mode. It sets ADC_MODE[1:0] to ‘0x’ (ADC
98 * Shutdown) at the end of the conversion or at the end of the conversion cycle in SCAN
99 * mode (default).
100 */
101#define MCP3464_CONFIG3_CONV_MODE_ONE_SHOT_SHUTDOWN 0
102#define MCP3464_CONFIG3_CONV_MODE_MASK GENMASK(7, 6)
103
104#define MCP3564_IRQ_REG 0x05
105#define MCP3464_EN_STP_MASK BIT(0)
106#define MCP3464_EN_FASTCMD_MASK BIT(1)
107#define MCP3464_IRQ_MODE_0_MASK BIT(2)
108#define MCP3464_IRQ_MODE_1_MASK BIT(3)
109#define MCP3564_POR_STATUS_MASK BIT(4)
110#define MCP3564_CRCCFG_STATUS_MASK BIT(5)
111#define MCP3564_DATA_READY_MASK BIT(6)
112
113#define MCP3564_MUX_REG 0x06
114#define MCP3564_MUX_VIN_P_MASK GENMASK(7, 4)
115#define MCP3564_MUX_VIN_N_MASK GENMASK(3, 0)
116#define MCP3564_MUX_SET(x, y) (FIELD_PREP(MCP3564_MUX_VIN_P_MASK, (x)) | \
117 FIELD_PREP(MCP3564_MUX_VIN_N_MASK, (y)))
118
119#define MCP3564_SCAN_REG 0x07
120#define MCP3564_SCAN_CH_SEL_MASK GENMASK(15, 0)
121#define MCP3564_SCAN_CH_SEL_SET(x) FIELD_PREP(MCP3564_SCAN_CH_SEL_MASK, (x))
122#define MCP3564_SCAN_DELAY_TIME_MASK GENMASK(23, 21)
123#define MCP3564_SCAN_DELAY_TIME_SET(x) FIELD_PREP(MCP3564_SCAN_DELAY_TIME_MASK, (x))
124#define MCP3564_SCAN_DEFAULT_VALUE 0
125
126#define MCP3564_TIMER_REG 0x08
127#define MCP3564_TIMER_DEFAULT_VALUE 0
128
129#define MCP3564_OFFSETCAL_REG 0x09
130#define MCP3564_DEFAULT_OFFSETCAL 0
131
132#define MCP3564_GAINCAL_REG 0x0A
133#define MCP3564_DEFAULT_GAINCAL 0x00800000
134
135#define MCP3564_RESERVED_B_REG 0x0B
136
137#define MCP3564_RESERVED_C_REG 0x0C
138#define MCP3564_C_REG_DEFAULT 0x50
139#define MCP3564R_C_REG_DEFAULT 0x30
140
141#define MCP3564_LOCK_REG 0x0D
142#define MCP3564_LOCK_WRITE_ACCESS_PASSWORD 0xA5
143#define MCP3564_RESERVED_E_REG 0x0E
144#define MCP3564_CRCCFG_REG 0x0F
145
146#define MCP3564_CMD_HW_ADDR_MASK GENMASK(7, 6)
147#define MCP3564_CMD_ADDR_MASK GENMASK(5, 2)
148
149#define MCP3564_HW_ADDR_MASK GENMASK(1, 0)
150
151#define MCP3564_FASTCMD_START 0x0A
152#define MCP3564_FASTCMD_RESET 0x0E
153
154#define MCP3461_HW_ID 0x0008
155#define MCP3462_HW_ID 0x0009
156#define MCP3464_HW_ID 0x000B
157
158#define MCP3561_HW_ID 0x000C
159#define MCP3562_HW_ID 0x000D
160#define MCP3564_HW_ID 0x000F
161#define MCP3564_HW_ID_MASK GENMASK(3, 0)
162
163#define MCP3564R_INT_VREF_MV 2400
164
165#define MCP3564_DATA_READY_TIMEOUT_MS 2000
166
167#define MCP3564_MAX_PGA 8
168#define MCP3564_MAX_BURNOUT_IDX 4
169#define MCP3564_MAX_CHANNELS 66
170
171enum mcp3564_ids {
172 mcp3461,
173 mcp3462,
174 mcp3464,
175 mcp3561,
176 mcp3562,
177 mcp3564,
178 mcp3461r,
179 mcp3462r,
180 mcp3464r,
181 mcp3561r,
182 mcp3562r,
183 mcp3564r,
184};
185
186enum mcp3564_delay_time {
187 MCP3564_NO_DELAY,
188 MCP3564_DELAY_8_DMCLK,
189 MCP3564_DELAY_16_DMCLK,
190 MCP3564_DELAY_32_DMCLK,
191 MCP3564_DELAY_64_DMCLK,
192 MCP3564_DELAY_128_DMCLK,
193 MCP3564_DELAY_256_DMCLK,
194 MCP3564_DELAY_512_DMCLK
195};
196
197enum mcp3564_adc_conversion_mode {
198 MCP3564_ADC_MODE_DEFAULT,
199 MCP3564_ADC_MODE_SHUTDOWN,
200 MCP3564_ADC_MODE_STANDBY,
201 MCP3564_ADC_MODE_CONVERSION
202};
203
204enum mcp3564_adc_bias_current {
205 MCP3564_BOOST_CURRENT_x0_50,
206 MCP3564_BOOST_CURRENT_x0_66,
207 MCP3564_BOOST_CURRENT_x1_00,
208 MCP3564_BOOST_CURRENT_x2_00
209};
210
211enum mcp3564_burnout {
212 MCP3564_CONFIG0_CS_SEL_0_0_uA,
213 MCP3564_CONFIG0_CS_SEL_0_9_uA,
214 MCP3564_CONFIG0_CS_SEL_3_7_uA,
215 MCP3564_CONFIG0_CS_SEL_15_uA
216};
217
218enum mcp3564_channel_names {
219 MCP3564_CH0,
220 MCP3564_CH1,
221 MCP3564_CH2,
222 MCP3564_CH3,
223 MCP3564_CH4,
224 MCP3564_CH5,
225 MCP3564_CH6,
226 MCP3564_CH7,
227 MCP3564_AGND,
228 MCP3564_AVDD,
229 MCP3564_RESERVED, /* do not use */
230 MCP3564_REFIN_POZ,
231 MCP3564_REFIN_NEG,
232 MCP3564_TEMP_DIODE_P,
233 MCP3564_TEMP_DIODE_M,
234 MCP3564_INTERNAL_VCM,
235};
236
237enum mcp3564_oversampling {
238 MCP3564_OVERSAMPLING_RATIO_32,
239 MCP3564_OVERSAMPLING_RATIO_64,
240 MCP3564_OVERSAMPLING_RATIO_128,
241 MCP3564_OVERSAMPLING_RATIO_256,
242 MCP3564_OVERSAMPLING_RATIO_512,
243 MCP3564_OVERSAMPLING_RATIO_1024,
244 MCP3564_OVERSAMPLING_RATIO_2048,
245 MCP3564_OVERSAMPLING_RATIO_4096,
246 MCP3564_OVERSAMPLING_RATIO_8192,
247 MCP3564_OVERSAMPLING_RATIO_16384,
248 MCP3564_OVERSAMPLING_RATIO_20480,
249 MCP3564_OVERSAMPLING_RATIO_24576,
250 MCP3564_OVERSAMPLING_RATIO_40960,
251 MCP3564_OVERSAMPLING_RATIO_49152,
252 MCP3564_OVERSAMPLING_RATIO_81920,
253 MCP3564_OVERSAMPLING_RATIO_98304
254};
255
256static const unsigned int mcp3564_oversampling_avail[] = {
257 [MCP3564_OVERSAMPLING_RATIO_32] = 32,
258 [MCP3564_OVERSAMPLING_RATIO_64] = 64,
259 [MCP3564_OVERSAMPLING_RATIO_128] = 128,
260 [MCP3564_OVERSAMPLING_RATIO_256] = 256,
261 [MCP3564_OVERSAMPLING_RATIO_512] = 512,
262 [MCP3564_OVERSAMPLING_RATIO_1024] = 1024,
263 [MCP3564_OVERSAMPLING_RATIO_2048] = 2048,
264 [MCP3564_OVERSAMPLING_RATIO_4096] = 4096,
265 [MCP3564_OVERSAMPLING_RATIO_8192] = 8192,
266 [MCP3564_OVERSAMPLING_RATIO_16384] = 16384,
267 [MCP3564_OVERSAMPLING_RATIO_20480] = 20480,
268 [MCP3564_OVERSAMPLING_RATIO_24576] = 24576,
269 [MCP3564_OVERSAMPLING_RATIO_40960] = 40960,
270 [MCP3564_OVERSAMPLING_RATIO_49152] = 49152,
271 [MCP3564_OVERSAMPLING_RATIO_81920] = 81920,
272 [MCP3564_OVERSAMPLING_RATIO_98304] = 98304
273};
274
275/*
276 * Current Source/Sink Selection Bits for Sensor Bias (source on VIN+/sink on VIN-)
277 */
278static const int mcp3564_burnout_avail[][2] = {
279 [MCP3564_CONFIG0_CS_SEL_0_0_uA] = { 0, 0 },
280 [MCP3564_CONFIG0_CS_SEL_0_9_uA] = { 0, 900 },
281 [MCP3564_CONFIG0_CS_SEL_3_7_uA] = { 0, 3700 },
282 [MCP3564_CONFIG0_CS_SEL_15_uA] = { 0, 15000 }
283};
284
285/*
286 * BOOST[1:0]: ADC Bias Current Selection
287 */
288static const char * const mcp3564_boost_current_avail[] = {
289 [MCP3564_BOOST_CURRENT_x0_50] = "0.5",
290 [MCP3564_BOOST_CURRENT_x0_66] = "0.66",
291 [MCP3564_BOOST_CURRENT_x1_00] = "1",
292 [MCP3564_BOOST_CURRENT_x2_00] = "2",
293};
294
295/*
296 * Calibration bias values
297 */
298static const int mcp3564_calib_bias[] = {
299 -8388608, /* min: -2^23 */
300 1, /* step: 1 */
301 8388607 /* max: 2^23 - 1 */
302};
303
304/*
305 * Calibration scale values
306 * The Gain Error Calibration register (GAINCAL) is an
307 * unsigned 24-bit register that holds the digital gain error
308 * calibration value, GAINCAL which could be calculated by
309 * GAINCAL (V/V) = (GAINCAL[23:0])/8388608
310 * The gain error calibration value range in equivalent voltage is [0; 2-2^(-23)]
311 */
312static const unsigned int mcp3564_calib_scale[] = {
313 0, /* min: 0 */
314 1, /* step: 1/8388608 */
315 16777215 /* max: 2 - 2^(-23) */
316};
317
318/* Programmable hardware gain x1/3, x1, x2, x4, x8, x16, x32, x64 */
319static const int mcp3564_hwgain_frac[] = {
320 3, 10,
321 1, 1,
322 2, 1,
323 4, 1,
324 8, 1,
325 16, 1,
326 32, 1,
327 64, 1
328};
329
330static const char *mcp3564_channel_labels[2] = {
331 "burnout_current", "temperature",
332};
333
334/**
335 * struct mcp3564_chip_info - chip specific data
336 * @name: device name
337 * @num_channels: number of channels
338 * @resolution: ADC resolution
339 * @have_vref: does the hardware have an internal voltage reference?
340 */
341struct mcp3564_chip_info {
342 const char *name;
343 unsigned int num_channels;
344 unsigned int resolution;
345 bool have_vref;
346};
347
348/**
349 * struct mcp3564_state - working data for a ADC device
350 * @chip_info: chip specific data
351 * @spi: SPI device structure
352 * @vref_mv: voltage reference value in miliVolts
353 * @lock: synchronize access to driver's state members
354 * @dev_addr: hardware device address
355 * @oversampling: the index inside oversampling list of the ADC
356 * @hwgain: the index inside hardware gain list of the ADC
357 * @scale_tbls: table with precalculated scale
358 * @calib_bias: calibration bias value
359 * @calib_scale: calibration scale value
360 * @current_boost_mode: the index inside current boost list of the ADC
361 * @burnout_mode: the index inside current bias list of the ADC
362 * @auto_zeroing_mux: set if ADC auto-zeroing algorithm is enabled
363 * @auto_zeroing_ref: set if ADC auto-Zeroing Reference Buffer Setting is enabled
364 * @have_vref: does the ADC have an internal voltage reference?
365 * @labels: table with channels labels
366 */
367struct mcp3564_state {
368 const struct mcp3564_chip_info *chip_info;
369 struct spi_device *spi;
370 unsigned short vref_mv;
371 struct mutex lock; /* Synchronize access to driver's state members */
372 u8 dev_addr;
373 enum mcp3564_oversampling oversampling;
374 unsigned int hwgain;
375 unsigned int scale_tbls[MCP3564_MAX_PGA][2];
376 int calib_bias;
377 int calib_scale;
378 unsigned int current_boost_mode;
379 enum mcp3564_burnout burnout_mode;
380 bool auto_zeroing_mux;
381 bool auto_zeroing_ref;
382 bool have_vref;
383 const char *labels[MCP3564_MAX_CHANNELS];
384};
385
386static inline u8 mcp3564_cmd_write(u8 chip_addr, u8 reg)
387{
388 return FIELD_PREP(MCP3564_CMD_HW_ADDR_MASK, chip_addr) |
389 FIELD_PREP(MCP3564_CMD_ADDR_MASK, reg) |
390 BIT(1);
391}
392
393static inline u8 mcp3564_cmd_read(u8 chip_addr, u8 reg)
394{
395 return FIELD_PREP(MCP3564_CMD_HW_ADDR_MASK, chip_addr) |
396 FIELD_PREP(MCP3564_CMD_ADDR_MASK, reg) |
397 BIT(0);
398}
399
400static int mcp3564_read_8bits(struct mcp3564_state *adc, u8 reg, u8 *val)
401{
402 int ret;
403 u8 tx_buf;
404 u8 rx_buf;
405
406 tx_buf = mcp3564_cmd_read(chip_addr: adc->dev_addr, reg);
407
408 ret = spi_write_then_read(spi: adc->spi, txbuf: &tx_buf, n_tx: sizeof(tx_buf),
409 rxbuf: &rx_buf, n_rx: sizeof(rx_buf));
410 *val = rx_buf;
411
412 return ret;
413}
414
415static int mcp3564_read_16bits(struct mcp3564_state *adc, u8 reg, u16 *val)
416{
417 int ret;
418 u8 tx_buf;
419 __be16 rx_buf;
420
421 tx_buf = mcp3564_cmd_read(chip_addr: adc->dev_addr, reg);
422
423 ret = spi_write_then_read(spi: adc->spi, txbuf: &tx_buf, n_tx: sizeof(tx_buf),
424 rxbuf: &rx_buf, n_rx: sizeof(rx_buf));
425 *val = be16_to_cpu(rx_buf);
426
427 return ret;
428}
429
430static int mcp3564_read_32bits(struct mcp3564_state *adc, u8 reg, u32 *val)
431{
432 int ret;
433 u8 tx_buf;
434 __be32 rx_buf;
435
436 tx_buf = mcp3564_cmd_read(chip_addr: adc->dev_addr, reg);
437
438 ret = spi_write_then_read(spi: adc->spi, txbuf: &tx_buf, n_tx: sizeof(tx_buf),
439 rxbuf: &rx_buf, n_rx: sizeof(rx_buf));
440 *val = be32_to_cpu(rx_buf);
441
442 return ret;
443}
444
445static int mcp3564_write_8bits(struct mcp3564_state *adc, u8 reg, u8 val)
446{
447 u8 tx_buf[2];
448
449 tx_buf[0] = mcp3564_cmd_write(chip_addr: adc->dev_addr, reg);
450 tx_buf[1] = val;
451
452 return spi_write_then_read(spi: adc->spi, txbuf: tx_buf, n_tx: sizeof(tx_buf), NULL, n_rx: 0);
453}
454
455static int mcp3564_write_24bits(struct mcp3564_state *adc, u8 reg, u32 val)
456{
457 __be32 val_be;
458
459 val |= (mcp3564_cmd_write(chip_addr: adc->dev_addr, reg) << 24);
460 val_be = cpu_to_be32(val);
461
462 return spi_write_then_read(spi: adc->spi, txbuf: &val_be, n_tx: sizeof(val_be), NULL, n_rx: 0);
463}
464
465static int mcp3564_fast_cmd(struct mcp3564_state *adc, u8 fast_cmd)
466{
467 u8 val;
468
469 val = FIELD_PREP(MCP3564_CMD_HW_ADDR_MASK, adc->dev_addr) |
470 FIELD_PREP(MCP3564_CMD_ADDR_MASK, fast_cmd);
471
472 return spi_write_then_read(spi: adc->spi, txbuf: &val, n_tx: 1, NULL, n_rx: 0);
473}
474
475static int mcp3564_update_8bits(struct mcp3564_state *adc, u8 reg, u32 mask, u8 val)
476{
477 u8 tmp;
478 int ret;
479
480 val &= mask;
481
482 ret = mcp3564_read_8bits(adc, reg, val: &tmp);
483 if (ret < 0)
484 return ret;
485
486 tmp &= ~mask;
487 tmp |= val;
488
489 return mcp3564_write_8bits(adc, reg, val: tmp);
490}
491
492static int mcp3564_set_current_boost_mode(struct iio_dev *indio_dev,
493 const struct iio_chan_spec *chan,
494 unsigned int mode)
495{
496 struct mcp3564_state *adc = iio_priv(indio_dev);
497 int ret;
498
499 dev_dbg(&indio_dev->dev, "%s: %d\n", __func__, mode);
500
501 mutex_lock(&adc->lock);
502 ret = mcp3564_update_8bits(adc, MCP3564_CONFIG2_REG, MCP3564_CONFIG2_BOOST_CURRENT_MASK,
503 FIELD_PREP(MCP3564_CONFIG2_BOOST_CURRENT_MASK, mode));
504
505 if (ret)
506 dev_err(&indio_dev->dev, "Failed to configure CONFIG2 register\n");
507 else
508 adc->current_boost_mode = mode;
509
510 mutex_unlock(lock: &adc->lock);
511
512 return ret;
513}
514
515static int mcp3564_get_current_boost_mode(struct iio_dev *indio_dev,
516 const struct iio_chan_spec *chan)
517{
518 struct mcp3564_state *adc = iio_priv(indio_dev);
519
520 return adc->current_boost_mode;
521}
522
523static const struct iio_enum mcp3564_current_boost_mode_enum = {
524 .items = mcp3564_boost_current_avail,
525 .num_items = ARRAY_SIZE(mcp3564_boost_current_avail),
526 .set = mcp3564_set_current_boost_mode,
527 .get = mcp3564_get_current_boost_mode,
528};
529
530static const struct iio_chan_spec_ext_info mcp3564_ext_info[] = {
531 IIO_ENUM("boost_current_gain", IIO_SHARED_BY_ALL, &mcp3564_current_boost_mode_enum),
532 {
533 .name = "boost_current_gain_available",
534 .shared = IIO_SHARED_BY_ALL,
535 .read = iio_enum_available_read,
536 .private = (uintptr_t)&mcp3564_current_boost_mode_enum,
537 },
538 { }
539};
540
541static ssize_t mcp3564_auto_zeroing_mux_show(struct device *dev,
542 struct device_attribute *attr,
543 char *buf)
544{
545 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
546 struct mcp3564_state *adc = iio_priv(indio_dev);
547
548 return sysfs_emit(buf, fmt: "%d\n", adc->auto_zeroing_mux);
549}
550
551static ssize_t mcp3564_auto_zeroing_mux_store(struct device *dev,
552 struct device_attribute *attr,
553 const char *buf, size_t len)
554{
555 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
556 struct mcp3564_state *adc = iio_priv(indio_dev);
557 bool auto_zero;
558 int ret;
559
560 ret = kstrtobool(s: buf, res: &auto_zero);
561 if (ret)
562 return ret;
563
564 mutex_lock(&adc->lock);
565 ret = mcp3564_update_8bits(adc, MCP3564_CONFIG2_REG, MCP3564_CONFIG2_AZ_MUX_MASK,
566 FIELD_PREP(MCP3564_CONFIG2_AZ_MUX_MASK, auto_zero));
567
568 if (ret)
569 dev_err(&indio_dev->dev, "Failed to update CONFIG2 register\n");
570 else
571 adc->auto_zeroing_mux = auto_zero;
572
573 mutex_unlock(lock: &adc->lock);
574
575 return ret ? ret : len;
576}
577
578static ssize_t mcp3564_auto_zeroing_ref_show(struct device *dev,
579 struct device_attribute *attr,
580 char *buf)
581{
582 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
583 struct mcp3564_state *adc = iio_priv(indio_dev);
584
585 return sysfs_emit(buf, fmt: "%d\n", adc->auto_zeroing_ref);
586}
587
588static ssize_t mcp3564_auto_zeroing_ref_store(struct device *dev,
589 struct device_attribute *attr,
590 const char *buf, size_t len)
591{
592 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
593 struct mcp3564_state *adc = iio_priv(indio_dev);
594 bool auto_zero;
595 int ret;
596
597 ret = kstrtobool(s: buf, res: &auto_zero);
598 if (ret)
599 return ret;
600
601 mutex_lock(&adc->lock);
602 ret = mcp3564_update_8bits(adc, MCP3564_CONFIG2_REG, MCP3564_CONFIG2_AZ_REF_MASK,
603 FIELD_PREP(MCP3564_CONFIG2_AZ_REF_MASK, auto_zero));
604
605 if (ret)
606 dev_err(&indio_dev->dev, "Failed to update CONFIG2 register\n");
607 else
608 adc->auto_zeroing_ref = auto_zero;
609
610 mutex_unlock(lock: &adc->lock);
611
612 return ret ? ret : len;
613}
614
615static const struct iio_chan_spec mcp3564_channel_template = {
616 .type = IIO_VOLTAGE,
617 .indexed = 1,
618 .differential = 1,
619 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
620 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE) |
621 BIT(IIO_CHAN_INFO_CALIBSCALE) |
622 BIT(IIO_CHAN_INFO_CALIBBIAS) |
623 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
624 .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_SCALE) |
625 BIT(IIO_CHAN_INFO_CALIBSCALE) |
626 BIT(IIO_CHAN_INFO_CALIBBIAS) |
627 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
628 .ext_info = mcp3564_ext_info,
629};
630
631static const struct iio_chan_spec mcp3564_temp_channel_template = {
632 .type = IIO_TEMP,
633 .channel = 0,
634 .address = ((MCP3564_TEMP_DIODE_P << 4) | MCP3564_TEMP_DIODE_M),
635 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
636 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SCALE) |
637 BIT(IIO_CHAN_INFO_CALIBSCALE) |
638 BIT(IIO_CHAN_INFO_CALIBBIAS) |
639 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
640 .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_SCALE) |
641 BIT(IIO_CHAN_INFO_CALIBSCALE) |
642 BIT(IIO_CHAN_INFO_CALIBBIAS) |
643 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
644};
645
646static const struct iio_chan_spec mcp3564_burnout_channel_template = {
647 .type = IIO_CURRENT,
648 .output = true,
649 .channel = 0,
650 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
651 .info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW),
652};
653
654/*
655 * Number of channels could be calculated:
656 * num_channels = single_ended_input + differential_input + temperature + burnout
657 * Eg. for MCP3561 (only 2 channels available: CH0 and CH1)
658 * single_ended_input = (CH0 - GND), (CH1 - GND) = 2
659 * differential_input = (CH0 - CH1), (CH0 - CH0) = 2
660 * num_channels = 2 + 2 + 2
661 * Generic formula is:
662 * num_channels = P^R(Number_of_single_ended_channels, 2) + 2 (temperature + burnout channels)
663 * P^R(Number_of_single_ended_channels, 2) is Permutations with Replacement of
664 * Number_of_single_ended_channels taken by 2
665 */
666static const struct mcp3564_chip_info mcp3564_chip_infos_tbl[] = {
667 [mcp3461] = {
668 .name = "mcp3461",
669 .num_channels = 6,
670 .resolution = 16,
671 .have_vref = false,
672 },
673 [mcp3462] = {
674 .name = "mcp3462",
675 .num_channels = 18,
676 .resolution = 16,
677 .have_vref = false,
678 },
679 [mcp3464] = {
680 .name = "mcp3464",
681 .num_channels = 66,
682 .resolution = 16,
683 .have_vref = false,
684 },
685 [mcp3561] = {
686 .name = "mcp3561",
687 .num_channels = 6,
688 .resolution = 24,
689 .have_vref = false,
690 },
691 [mcp3562] = {
692 .name = "mcp3562",
693 .num_channels = 18,
694 .resolution = 24,
695 .have_vref = false,
696 },
697 [mcp3564] = {
698 .name = "mcp3564",
699 .num_channels = 66,
700 .resolution = 24,
701 .have_vref = false,
702 },
703 [mcp3461r] = {
704 .name = "mcp3461r",
705 .num_channels = 6,
706 .resolution = 16,
707 .have_vref = false,
708 },
709 [mcp3462r] = {
710 .name = "mcp3462r",
711 .num_channels = 18,
712 .resolution = 16,
713 .have_vref = true,
714 },
715 [mcp3464r] = {
716 .name = "mcp3464r",
717 .num_channels = 66,
718 .resolution = 16,
719 .have_vref = true,
720 },
721 [mcp3561r] = {
722 .name = "mcp3561r",
723 .num_channels = 6,
724 .resolution = 24,
725 .have_vref = true,
726 },
727 [mcp3562r] = {
728 .name = "mcp3562r",
729 .num_channels = 18,
730 .resolution = 24,
731 .have_vref = true,
732 },
733 [mcp3564r] = {
734 .name = "mcp3564r",
735 .num_channels = 66,
736 .resolution = 24,
737 .have_vref = true,
738 },
739};
740
741static int mcp3564_read_single_value(struct iio_dev *indio_dev,
742 struct iio_chan_spec const *channel,
743 int *val)
744{
745 struct mcp3564_state *adc = iio_priv(indio_dev);
746 int ret;
747 u8 tmp;
748 int ret_read = 0;
749
750 ret = mcp3564_write_8bits(adc, MCP3564_MUX_REG, val: channel->address);
751 if (ret)
752 return ret;
753
754 /* Start ADC Conversion using fast command (overwrites ADC_MODE[1:0] = 11) */
755 ret = mcp3564_fast_cmd(adc, MCP3564_FASTCMD_START);
756 if (ret)
757 return ret;
758
759 /*
760 * Check if the conversion is ready. If not, wait a little bit, and
761 * in case of timeout exit with an error.
762 */
763 ret = read_poll_timeout(mcp3564_read_8bits, ret_read,
764 ret_read || !(tmp & MCP3564_DATA_READY_MASK),
765 20000, MCP3564_DATA_READY_TIMEOUT_MS * 1000, true,
766 adc, MCP3564_IRQ_REG, &tmp);
767
768 /* failed to read status register */
769 if (ret_read)
770 return ret_read;
771
772 if (ret)
773 return ret;
774
775 if (tmp & MCP3564_DATA_READY_MASK)
776 /* failing to finish conversion */
777 return -EBUSY;
778
779 return mcp3564_read_32bits(adc, MCP3564_ADCDATA_REG, val);
780}
781
782static int mcp3564_read_avail(struct iio_dev *indio_dev,
783 struct iio_chan_spec const *channel,
784 const int **vals, int *type,
785 int *length, long mask)
786{
787 struct mcp3564_state *adc = iio_priv(indio_dev);
788
789 switch (mask) {
790 case IIO_CHAN_INFO_RAW:
791 if (!channel->output)
792 return -EINVAL;
793
794 *vals = mcp3564_burnout_avail[0];
795 *length = ARRAY_SIZE(mcp3564_burnout_avail) * 2;
796 *type = IIO_VAL_INT_PLUS_MICRO;
797 return IIO_AVAIL_LIST;
798 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
799 *vals = mcp3564_oversampling_avail;
800 *length = ARRAY_SIZE(mcp3564_oversampling_avail);
801 *type = IIO_VAL_INT;
802 return IIO_AVAIL_LIST;
803 case IIO_CHAN_INFO_SCALE:
804 *vals = (int *)adc->scale_tbls;
805 *length = ARRAY_SIZE(adc->scale_tbls) * 2;
806 *type = IIO_VAL_INT_PLUS_NANO;
807 return IIO_AVAIL_LIST;
808 case IIO_CHAN_INFO_CALIBBIAS:
809 *vals = mcp3564_calib_bias;
810 *type = IIO_VAL_INT;
811 return IIO_AVAIL_RANGE;
812 case IIO_CHAN_INFO_CALIBSCALE:
813 *vals = mcp3564_calib_scale;
814 *type = IIO_VAL_INT;
815 return IIO_AVAIL_RANGE;
816 default:
817 return -EINVAL;
818 }
819}
820
821static int mcp3564_read_raw(struct iio_dev *indio_dev,
822 struct iio_chan_spec const *channel,
823 int *val, int *val2, long mask)
824{
825 struct mcp3564_state *adc = iio_priv(indio_dev);
826 int ret;
827
828 switch (mask) {
829 case IIO_CHAN_INFO_RAW:
830 if (channel->output) {
831 mutex_lock(&adc->lock);
832 *val = mcp3564_burnout_avail[adc->burnout_mode][0];
833 *val2 = mcp3564_burnout_avail[adc->burnout_mode][1];
834 mutex_unlock(lock: &adc->lock);
835 return IIO_VAL_INT_PLUS_MICRO;
836 }
837
838 ret = mcp3564_read_single_value(indio_dev, channel, val);
839 if (ret)
840 return -EINVAL;
841 return IIO_VAL_INT;
842 case IIO_CHAN_INFO_SCALE:
843 mutex_lock(&adc->lock);
844 *val = adc->scale_tbls[adc->hwgain][0];
845 *val2 = adc->scale_tbls[adc->hwgain][1];
846 mutex_unlock(lock: &adc->lock);
847 return IIO_VAL_INT_PLUS_NANO;
848 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
849 *val = mcp3564_oversampling_avail[adc->oversampling];
850 return IIO_VAL_INT;
851 case IIO_CHAN_INFO_CALIBBIAS:
852 *val = adc->calib_bias;
853 return IIO_VAL_INT;
854 case IIO_CHAN_INFO_CALIBSCALE:
855 *val = adc->calib_scale;
856 return IIO_VAL_INT;
857 default:
858 return -EINVAL;
859 }
860}
861
862static int mcp3564_write_raw_get_fmt(struct iio_dev *indio_dev,
863 struct iio_chan_spec const *chan,
864 long info)
865{
866 switch (info) {
867 case IIO_CHAN_INFO_RAW:
868 return IIO_VAL_INT_PLUS_MICRO;
869 case IIO_CHAN_INFO_CALIBBIAS:
870 case IIO_CHAN_INFO_CALIBSCALE:
871 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
872 return IIO_VAL_INT;
873 case IIO_CHAN_INFO_SCALE:
874 return IIO_VAL_INT_PLUS_NANO;
875 default:
876 return -EINVAL;
877 }
878}
879
880static int mcp3564_write_raw(struct iio_dev *indio_dev,
881 struct iio_chan_spec const *channel, int val,
882 int val2, long mask)
883{
884 struct mcp3564_state *adc = iio_priv(indio_dev);
885 int tmp;
886 unsigned int hwgain;
887 enum mcp3564_burnout burnout;
888 int ret = 0;
889
890 switch (mask) {
891 case IIO_CHAN_INFO_RAW:
892 if (!channel->output)
893 return -EINVAL;
894
895 for (burnout = 0; burnout < MCP3564_MAX_BURNOUT_IDX; burnout++)
896 if (val == mcp3564_burnout_avail[burnout][0] &&
897 val2 == mcp3564_burnout_avail[burnout][1])
898 break;
899
900 if (burnout == MCP3564_MAX_BURNOUT_IDX)
901 return -EINVAL;
902
903 if (burnout == adc->burnout_mode)
904 return ret;
905
906 mutex_lock(&adc->lock);
907 ret = mcp3564_update_8bits(adc, MCP3564_CONFIG0_REG,
908 MCP3564_CONFIG0_CS_SEL_MASK,
909 FIELD_PREP(MCP3564_CONFIG0_CS_SEL_MASK, burnout));
910
911 if (ret)
912 dev_err(&indio_dev->dev, "Failed to configure burnout current\n");
913 else
914 adc->burnout_mode = burnout;
915 mutex_unlock(lock: &adc->lock);
916 return ret;
917 case IIO_CHAN_INFO_CALIBBIAS:
918 if (val < mcp3564_calib_bias[0] || val > mcp3564_calib_bias[2])
919 return -EINVAL;
920
921 mutex_lock(&adc->lock);
922 ret = mcp3564_write_24bits(adc, MCP3564_OFFSETCAL_REG, val);
923 if (!ret)
924 adc->calib_bias = val;
925 mutex_unlock(lock: &adc->lock);
926 return ret;
927 case IIO_CHAN_INFO_CALIBSCALE:
928 if (val < mcp3564_calib_scale[0] || val > mcp3564_calib_scale[2])
929 return -EINVAL;
930
931 if (adc->calib_scale == val)
932 return ret;
933
934 mutex_lock(&adc->lock);
935 ret = mcp3564_write_24bits(adc, MCP3564_GAINCAL_REG, val);
936 if (!ret)
937 adc->calib_scale = val;
938 mutex_unlock(lock: &adc->lock);
939 return ret;
940 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
941 if (val < 0)
942 return -EINVAL;
943
944 tmp = find_closest(val, mcp3564_oversampling_avail,
945 ARRAY_SIZE(mcp3564_oversampling_avail));
946
947 if (adc->oversampling == tmp)
948 return ret;
949
950 mutex_lock(&adc->lock);
951 ret = mcp3564_update_8bits(adc, MCP3564_CONFIG1_REG,
952 MCP3564_CONFIG1_OVERSPL_RATIO_MASK,
953 FIELD_PREP(MCP3564_CONFIG1_OVERSPL_RATIO_MASK,
954 adc->oversampling));
955 if (!ret)
956 adc->oversampling = tmp;
957 mutex_unlock(lock: &adc->lock);
958 return ret;
959 case IIO_CHAN_INFO_SCALE:
960 for (hwgain = 0; hwgain < MCP3564_MAX_PGA; hwgain++)
961 if (val == adc->scale_tbls[hwgain][0] &&
962 val2 == adc->scale_tbls[hwgain][1])
963 break;
964
965 if (hwgain == MCP3564_MAX_PGA)
966 return -EINVAL;
967
968 if (hwgain == adc->hwgain)
969 return ret;
970
971 mutex_lock(&adc->lock);
972 ret = mcp3564_update_8bits(adc, MCP3564_CONFIG2_REG,
973 MCP3564_CONFIG2_HARDWARE_GAIN_MASK,
974 FIELD_PREP(MCP3564_CONFIG2_HARDWARE_GAIN_MASK, hwgain));
975 if (!ret)
976 adc->hwgain = hwgain;
977
978 mutex_unlock(lock: &adc->lock);
979 return ret;
980 default:
981 return -EINVAL;
982 }
983}
984
985static int mcp3564_read_label(struct iio_dev *indio_dev,
986 struct iio_chan_spec const *chan, char *label)
987{
988 struct mcp3564_state *adc = iio_priv(indio_dev);
989
990 return sysfs_emit(buf: label, fmt: "%s\n", adc->labels[chan->scan_index]);
991}
992
993static int mcp3564_parse_fw_children(struct iio_dev *indio_dev)
994{
995 struct mcp3564_state *adc = iio_priv(indio_dev);
996 struct device *dev = &adc->spi->dev;
997 struct iio_chan_spec *channels;
998 struct iio_chan_spec chanspec = mcp3564_channel_template;
999 struct iio_chan_spec temp_chanspec = mcp3564_temp_channel_template;
1000 struct iio_chan_spec burnout_chanspec = mcp3564_burnout_channel_template;
1001 int chan_idx = 0;
1002 unsigned int num_ch;
1003 u32 inputs[2];
1004 const char *node_name;
1005 const char *label;
1006 int ret;
1007
1008 num_ch = device_get_child_node_count(dev);
1009 if (num_ch == 0)
1010 return dev_err_probe(dev: &indio_dev->dev, err: -ENODEV,
1011 fmt: "FW has no channels defined\n");
1012
1013 /* Reserve space for burnout and temperature channel */
1014 num_ch += 2;
1015
1016 if (num_ch > adc->chip_info->num_channels)
1017 return dev_err_probe(dev, err: -EINVAL, fmt: "Too many channels %d > %d\n",
1018 num_ch, adc->chip_info->num_channels);
1019
1020 channels = devm_kcalloc(dev, n: num_ch, size: sizeof(*channels), GFP_KERNEL);
1021 if (!channels)
1022 return -ENOMEM;
1023
1024 device_for_each_child_node_scoped(dev, child) {
1025 node_name = fwnode_get_name(fwnode: child);
1026
1027 if (fwnode_property_present(fwnode: child, propname: "diff-channels")) {
1028 ret = fwnode_property_read_u32_array(fwnode: child,
1029 propname: "diff-channels",
1030 val: inputs,
1031 ARRAY_SIZE(inputs));
1032 if (ret)
1033 return ret;
1034
1035 chanspec.differential = 1;
1036 } else {
1037 ret = fwnode_property_read_u32(fwnode: child, propname: "reg", val: &inputs[0]);
1038 if (ret)
1039 return ret;
1040
1041 chanspec.differential = 0;
1042 inputs[1] = MCP3564_AGND;
1043 }
1044
1045 if (inputs[0] > MCP3564_INTERNAL_VCM ||
1046 inputs[1] > MCP3564_INTERNAL_VCM)
1047 return dev_err_probe(dev: &indio_dev->dev, err: -EINVAL,
1048 fmt: "Channel index > %d, for %s\n",
1049 MCP3564_INTERNAL_VCM + 1,
1050 node_name);
1051
1052 chanspec.address = (inputs[0] << 4) | inputs[1];
1053 chanspec.channel = inputs[0];
1054 chanspec.channel2 = inputs[1];
1055 chanspec.scan_index = chan_idx;
1056
1057 if (fwnode_property_present(fwnode: child, propname: "label")) {
1058 fwnode_property_read_string(fwnode: child, propname: "label", val: &label);
1059 adc->labels[chan_idx] = label;
1060 }
1061
1062 channels[chan_idx] = chanspec;
1063 chan_idx++;
1064 }
1065
1066 /* Add burnout current channel */
1067 burnout_chanspec.scan_index = chan_idx;
1068 channels[chan_idx] = burnout_chanspec;
1069 adc->labels[chan_idx] = mcp3564_channel_labels[0];
1070 chanspec.scan_index = chan_idx;
1071 chan_idx++;
1072
1073 /* Add temperature channel */
1074 temp_chanspec.scan_index = chan_idx;
1075 channels[chan_idx] = temp_chanspec;
1076 adc->labels[chan_idx] = mcp3564_channel_labels[1];
1077 chan_idx++;
1078
1079 indio_dev->num_channels = chan_idx;
1080 indio_dev->channels = channels;
1081
1082 return 0;
1083}
1084
1085static void mcp3564_fill_scale_tbls(struct mcp3564_state *adc)
1086{
1087 unsigned int pow = adc->chip_info->resolution - 1;
1088 int ref;
1089 unsigned int i;
1090 int tmp0;
1091 u64 tmp1;
1092
1093 for (i = 0; i < MCP3564_MAX_PGA; i++) {
1094 ref = adc->vref_mv;
1095 tmp1 = ((u64)ref * NANO) >> pow;
1096 div_u64_rem(dividend: tmp1, NANO, remainder: &tmp0);
1097
1098 tmp1 = tmp1 * mcp3564_hwgain_frac[(2 * i) + 1];
1099 tmp0 = (int)div_u64(dividend: tmp1, divisor: mcp3564_hwgain_frac[2 * i]);
1100
1101 adc->scale_tbls[i][1] = tmp0;
1102 }
1103}
1104
1105static int mcp3564_config(struct iio_dev *indio_dev, bool *use_internal_vref_attr)
1106{
1107 struct mcp3564_state *adc = iio_priv(indio_dev);
1108 struct device *dev = &adc->spi->dev;
1109 u8 tmp_reg;
1110 u16 tmp_u16;
1111 enum mcp3564_ids ids;
1112 int ret = 0;
1113 unsigned int tmp = 0x01;
1114 bool internal_vref;
1115 bool err = false;
1116
1117 /*
1118 * The address is set on a per-device basis by fuses in the factory,
1119 * configured on request. If not requested, the fuses are set for 0x1.
1120 * The device address is part of the device markings to avoid
1121 * potential confusion. This address is coded on two bits, so four possible
1122 * addresses are available when multiple devices are present on the same
1123 * SPI bus with only one Chip Select line for all devices.
1124 */
1125 device_property_read_u32(dev, propname: "microchip,hw-device-address", val: &tmp);
1126
1127 if (tmp > 3) {
1128 dev_err_probe(dev, err: tmp,
1129 fmt: "invalid device address. Must be in range 0-3.\n");
1130 return -EINVAL;
1131 }
1132
1133 adc->dev_addr = FIELD_GET(MCP3564_HW_ADDR_MASK, tmp);
1134
1135 dev_dbg(dev, "use HW device address %i\n", adc->dev_addr);
1136
1137 ret = mcp3564_read_8bits(adc, MCP3564_RESERVED_C_REG, val: &tmp_reg);
1138 if (ret < 0)
1139 return ret;
1140
1141 switch (tmp_reg) {
1142 case MCP3564_C_REG_DEFAULT:
1143 adc->have_vref = false;
1144 break;
1145 case MCP3564R_C_REG_DEFAULT:
1146 adc->have_vref = true;
1147 break;
1148 default:
1149 dev_info(dev, "Unknown chip found: %d\n", tmp_reg);
1150 err = true;
1151 }
1152
1153 if (!err) {
1154 ret = mcp3564_read_16bits(adc, MCP3564_RESERVED_E_REG, val: &tmp_u16);
1155 if (ret < 0)
1156 return ret;
1157
1158 switch (tmp_u16 & MCP3564_HW_ID_MASK) {
1159 case MCP3461_HW_ID:
1160 if (adc->have_vref)
1161 ids = mcp3461r;
1162 else
1163 ids = mcp3461;
1164 break;
1165 case MCP3462_HW_ID:
1166 if (adc->have_vref)
1167 ids = mcp3462r;
1168 else
1169 ids = mcp3462;
1170 break;
1171 case MCP3464_HW_ID:
1172 if (adc->have_vref)
1173 ids = mcp3464r;
1174 else
1175 ids = mcp3464;
1176 break;
1177 case MCP3561_HW_ID:
1178 if (adc->have_vref)
1179 ids = mcp3561r;
1180 else
1181 ids = mcp3561;
1182 break;
1183 case MCP3562_HW_ID:
1184 if (adc->have_vref)
1185 ids = mcp3562r;
1186 else
1187 ids = mcp3562;
1188 break;
1189 case MCP3564_HW_ID:
1190 if (adc->have_vref)
1191 ids = mcp3564r;
1192 else
1193 ids = mcp3564;
1194 break;
1195 default:
1196 dev_info(dev, "Unknown chip found: %d\n", tmp_u16);
1197 err = true;
1198 }
1199 }
1200
1201 if (err) {
1202 /*
1203 * If failed to identify the hardware based on internal registers,
1204 * try using fallback compatible in device tree to deal with some newer part number.
1205 */
1206 adc->chip_info = spi_get_device_match_data(sdev: adc->spi);
1207 adc->have_vref = adc->chip_info->have_vref;
1208 } else {
1209 adc->chip_info = &mcp3564_chip_infos_tbl[ids];
1210 }
1211
1212 dev_dbg(dev, "Found %s chip\n", adc->chip_info->name);
1213
1214 ret = devm_regulator_get_enable_read_voltage(dev, id: "vref");
1215 if (ret < 0 && ret != -ENODEV)
1216 return dev_err_probe(dev, err: ret, fmt: "Failed to get vref voltage\n");
1217
1218 internal_vref = ret == -ENODEV;
1219 adc->vref_mv = internal_vref ? MCP3564R_INT_VREF_MV : ret / MILLI;
1220 *use_internal_vref_attr = internal_vref;
1221
1222 if (internal_vref) {
1223 /* Check if chip has internal vref */
1224 if (!adc->have_vref)
1225 return dev_err_probe(dev, err: -ENODEV, fmt: "Unknown Vref\n");
1226
1227 dev_dbg(dev, "%s: Using internal Vref\n", __func__);
1228 } else {
1229 dev_dbg(dev, "%s: Using External Vref\n", __func__);
1230 }
1231
1232 ret = mcp3564_parse_fw_children(indio_dev);
1233 if (ret)
1234 return ret;
1235
1236 /*
1237 * Command sequence that ensures a recovery with the desired settings
1238 * in any cases of loss-of-power scenario (Full Chip Reset):
1239 * - Write LOCK register to 0xA5
1240 * - Write IRQ register to 0x03
1241 * - Send "Device Full Reset" fast command
1242 * - Wait 1ms for "Full Reset" to complete
1243 */
1244 ret = mcp3564_write_8bits(adc, MCP3564_LOCK_REG, MCP3564_LOCK_WRITE_ACCESS_PASSWORD);
1245 if (ret)
1246 return ret;
1247
1248 ret = mcp3564_write_8bits(adc, MCP3564_IRQ_REG, val: 0x03);
1249 if (ret)
1250 return ret;
1251
1252 ret = mcp3564_fast_cmd(adc, MCP3564_FASTCMD_RESET);
1253 if (ret)
1254 return ret;
1255
1256 /*
1257 * After Full reset wait some time to be able to fully reset the part and place
1258 * it back in a default configuration.
1259 * From datasheet: POR (Power On Reset Time) is ~1us
1260 * 1ms should be enough.
1261 */
1262 mdelay(1);
1263
1264 /* set a gain of 1x for GAINCAL */
1265 ret = mcp3564_write_24bits(adc, MCP3564_GAINCAL_REG, MCP3564_DEFAULT_GAINCAL);
1266 if (ret)
1267 return ret;
1268
1269 adc->calib_scale = MCP3564_DEFAULT_GAINCAL;
1270
1271 ret = mcp3564_write_24bits(adc, MCP3564_OFFSETCAL_REG, MCP3564_DEFAULT_OFFSETCAL);
1272 if (ret)
1273 return ret;
1274
1275 ret = mcp3564_write_24bits(adc, MCP3564_TIMER_REG, MCP3564_TIMER_DEFAULT_VALUE);
1276 if (ret)
1277 return ret;
1278
1279 ret = mcp3564_write_24bits(adc, MCP3564_SCAN_REG,
1280 MCP3564_SCAN_DELAY_TIME_SET(MCP3564_NO_DELAY) |
1281 MCP3564_SCAN_CH_SEL_SET(MCP3564_SCAN_DEFAULT_VALUE));
1282 if (ret)
1283 return ret;
1284
1285 ret = mcp3564_write_8bits(adc, MCP3564_MUX_REG, MCP3564_MUX_SET(MCP3564_CH0, MCP3564_CH1));
1286 if (ret)
1287 return ret;
1288
1289 ret = mcp3564_write_8bits(adc, MCP3564_IRQ_REG,
1290 FIELD_PREP(MCP3464_EN_FASTCMD_MASK, 1) |
1291 FIELD_PREP(MCP3464_EN_STP_MASK, 1));
1292 if (ret)
1293 return ret;
1294
1295 tmp_reg = FIELD_PREP(MCP3464_CONFIG3_CONV_MODE_MASK,
1296 MCP3464_CONFIG3_CONV_MODE_ONE_SHOT_STANDBY);
1297 tmp_reg |= FIELD_PREP(MCP3464_CONFIG3_DATA_FORMAT_MASK,
1298 MCP3464_CONFIG3_DATA_FMT_32B_SGN_EXT);
1299 tmp_reg |= MCP3464_CONFIG3_EN_OFFCAL_MASK;
1300 tmp_reg |= MCP3464_CONFIG3_EN_GAINCAL_MASK;
1301
1302 ret = mcp3564_write_8bits(adc, MCP3564_CONFIG3_REG, val: tmp_reg);
1303 if (ret)
1304 return ret;
1305
1306 tmp_reg = FIELD_PREP(MCP3564_CONFIG2_BOOST_CURRENT_MASK, MCP3564_BOOST_CURRENT_x1_00);
1307 tmp_reg |= FIELD_PREP(MCP3564_CONFIG2_HARDWARE_GAIN_MASK, 0x01);
1308 tmp_reg |= FIELD_PREP(MCP3564_CONFIG2_AZ_MUX_MASK, 1);
1309
1310 ret = mcp3564_write_8bits(adc, MCP3564_CONFIG2_REG, val: tmp_reg);
1311 if (ret)
1312 return ret;
1313
1314 adc->hwgain = 0x01;
1315 adc->auto_zeroing_mux = true;
1316 adc->auto_zeroing_ref = false;
1317 adc->current_boost_mode = MCP3564_BOOST_CURRENT_x1_00;
1318
1319 tmp_reg = FIELD_PREP(MCP3564_CONFIG1_OVERSPL_RATIO_MASK, MCP3564_OVERSAMPLING_RATIO_98304);
1320
1321 ret = mcp3564_write_8bits(adc, MCP3564_CONFIG1_REG, val: tmp_reg);
1322 if (ret)
1323 return ret;
1324
1325 adc->oversampling = MCP3564_OVERSAMPLING_RATIO_98304;
1326
1327 tmp_reg = FIELD_PREP(MCP3564_CONFIG0_ADC_MODE_MASK, MCP3564_ADC_MODE_STANDBY);
1328 tmp_reg |= FIELD_PREP(MCP3564_CONFIG0_CS_SEL_MASK, MCP3564_CONFIG0_CS_SEL_0_0_uA);
1329 tmp_reg |= FIELD_PREP(MCP3564_CONFIG0_CLK_SEL_MASK, MCP3564_CONFIG0_USE_INT_CLK);
1330 tmp_reg |= MCP3456_CONFIG0_BIT6_DEFAULT;
1331
1332 if (internal_vref)
1333 tmp_reg |= FIELD_PREP(MCP3456_CONFIG0_VREF_MASK, 1);
1334
1335 ret = mcp3564_write_8bits(adc, MCP3564_CONFIG0_REG, val: tmp_reg);
1336
1337 adc->burnout_mode = MCP3564_CONFIG0_CS_SEL_0_0_uA;
1338
1339 return ret;
1340}
1341
1342static IIO_DEVICE_ATTR(auto_zeroing_ref_enable, 0644,
1343 mcp3564_auto_zeroing_ref_show,
1344 mcp3564_auto_zeroing_ref_store, 0);
1345
1346static IIO_DEVICE_ATTR(auto_zeroing_mux_enable, 0644,
1347 mcp3564_auto_zeroing_mux_show,
1348 mcp3564_auto_zeroing_mux_store, 0);
1349
1350static struct attribute *mcp3564_attributes[] = {
1351 &iio_dev_attr_auto_zeroing_mux_enable.dev_attr.attr,
1352 NULL
1353};
1354
1355static struct attribute *mcp3564r_attributes[] = {
1356 &iio_dev_attr_auto_zeroing_mux_enable.dev_attr.attr,
1357 &iio_dev_attr_auto_zeroing_ref_enable.dev_attr.attr,
1358 NULL
1359};
1360
1361static struct attribute_group mcp3564_attribute_group = {
1362 .attrs = mcp3564_attributes,
1363};
1364
1365static struct attribute_group mcp3564r_attribute_group = {
1366 .attrs = mcp3564r_attributes,
1367};
1368
1369static const struct iio_info mcp3564_info = {
1370 .read_raw = mcp3564_read_raw,
1371 .read_avail = mcp3564_read_avail,
1372 .write_raw = mcp3564_write_raw,
1373 .write_raw_get_fmt = mcp3564_write_raw_get_fmt,
1374 .read_label = mcp3564_read_label,
1375 .attrs = &mcp3564_attribute_group,
1376};
1377
1378static const struct iio_info mcp3564r_info = {
1379 .read_raw = mcp3564_read_raw,
1380 .read_avail = mcp3564_read_avail,
1381 .write_raw = mcp3564_write_raw,
1382 .write_raw_get_fmt = mcp3564_write_raw_get_fmt,
1383 .read_label = mcp3564_read_label,
1384 .attrs = &mcp3564r_attribute_group,
1385};
1386
1387static int mcp3564_probe(struct spi_device *spi)
1388{
1389 int ret;
1390 struct iio_dev *indio_dev;
1391 struct mcp3564_state *adc;
1392 bool use_internal_vref_attr;
1393
1394 indio_dev = devm_iio_device_alloc(parent: &spi->dev, sizeof_priv: sizeof(*adc));
1395 if (!indio_dev)
1396 return -ENOMEM;
1397
1398 adc = iio_priv(indio_dev);
1399 adc->spi = spi;
1400
1401 dev_dbg(&spi->dev, "%s: probe(spi = 0x%p)\n", __func__, spi);
1402
1403 /*
1404 * Do any chip specific initialization, e.g:
1405 * read/write some registers
1406 * enable/disable certain channels
1407 * change the sampling rate to the requested value
1408 */
1409 ret = mcp3564_config(indio_dev, use_internal_vref_attr: &use_internal_vref_attr);
1410 if (ret)
1411 return dev_err_probe(dev: &spi->dev, err: ret,
1412 fmt: "Can't configure MCP356X device\n");
1413
1414 dev_dbg(&spi->dev, "%s: Vref (mV): %d\n", __func__, adc->vref_mv);
1415
1416 mcp3564_fill_scale_tbls(adc);
1417
1418 indio_dev->name = adc->chip_info->name;
1419 indio_dev->modes = INDIO_DIRECT_MODE;
1420
1421 if (use_internal_vref_attr)
1422 indio_dev->info = &mcp3564r_info;
1423 else
1424 indio_dev->info = &mcp3564_info;
1425
1426 mutex_init(&adc->lock);
1427
1428 ret = devm_iio_device_register(&spi->dev, indio_dev);
1429 if (ret)
1430 return dev_err_probe(dev: &spi->dev, err: ret,
1431 fmt: "Can't register IIO device\n");
1432
1433 return 0;
1434}
1435
1436static const struct of_device_id mcp3564_dt_ids[] = {
1437 { .compatible = "microchip,mcp3461", .data = &mcp3564_chip_infos_tbl[mcp3461] },
1438 { .compatible = "microchip,mcp3462", .data = &mcp3564_chip_infos_tbl[mcp3462] },
1439 { .compatible = "microchip,mcp3464", .data = &mcp3564_chip_infos_tbl[mcp3464] },
1440 { .compatible = "microchip,mcp3561", .data = &mcp3564_chip_infos_tbl[mcp3561] },
1441 { .compatible = "microchip,mcp3562", .data = &mcp3564_chip_infos_tbl[mcp3562] },
1442 { .compatible = "microchip,mcp3564", .data = &mcp3564_chip_infos_tbl[mcp3564] },
1443 { .compatible = "microchip,mcp3461r", .data = &mcp3564_chip_infos_tbl[mcp3461r] },
1444 { .compatible = "microchip,mcp3462r", .data = &mcp3564_chip_infos_tbl[mcp3462r] },
1445 { .compatible = "microchip,mcp3464r", .data = &mcp3564_chip_infos_tbl[mcp3464r] },
1446 { .compatible = "microchip,mcp3561r", .data = &mcp3564_chip_infos_tbl[mcp3561r] },
1447 { .compatible = "microchip,mcp3562r", .data = &mcp3564_chip_infos_tbl[mcp3562r] },
1448 { .compatible = "microchip,mcp3564r", .data = &mcp3564_chip_infos_tbl[mcp3564r] },
1449 { }
1450};
1451MODULE_DEVICE_TABLE(of, mcp3564_dt_ids);
1452
1453static const struct spi_device_id mcp3564_id[] = {
1454 { "mcp3461", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3461] },
1455 { "mcp3462", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3462] },
1456 { "mcp3464", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3464] },
1457 { "mcp3561", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3561] },
1458 { "mcp3562", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3562] },
1459 { "mcp3564", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3564] },
1460 { "mcp3461r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3461r] },
1461 { "mcp3462r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3462r] },
1462 { "mcp3464r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3464r] },
1463 { "mcp3561r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3561r] },
1464 { "mcp3562r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3562r] },
1465 { "mcp3564r", (kernel_ulong_t)&mcp3564_chip_infos_tbl[mcp3564r] },
1466 { }
1467};
1468MODULE_DEVICE_TABLE(spi, mcp3564_id);
1469
1470static struct spi_driver mcp3564_driver = {
1471 .driver = {
1472 .name = "mcp3564",
1473 .of_match_table = mcp3564_dt_ids,
1474 },
1475 .probe = mcp3564_probe,
1476 .id_table = mcp3564_id,
1477};
1478
1479module_spi_driver(mcp3564_driver);
1480
1481MODULE_AUTHOR("Marius Cristea <marius.cristea@microchip.com>");
1482MODULE_DESCRIPTION("Microchip MCP346x/MCP346xR and MCP356x/MCP356xR ADCs");
1483MODULE_LICENSE("GPL v2");
1484

source code of linux/drivers/iio/adc/mcp3564.c