xref: /openbmc/linux/drivers/iio/adc/ad9467.c (revision b737eecd)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Analog Devices AD9467 SPI ADC driver
4  *
5  * Copyright 2012-2020 Analog Devices Inc.
6  */
7 
8 #include <linux/module.h>
9 #include <linux/device.h>
10 #include <linux/kernel.h>
11 #include <linux/slab.h>
12 #include <linux/spi/spi.h>
13 #include <linux/err.h>
14 #include <linux/delay.h>
15 #include <linux/gpio/consumer.h>
16 #include <linux/of_device.h>
17 
18 
19 #include <linux/iio/iio.h>
20 #include <linux/iio/sysfs.h>
21 
22 #include <linux/clk.h>
23 
24 #include <linux/iio/adc/adi-axi-adc.h>
25 
26 /*
27  * ADI High-Speed ADC common spi interface registers
28  * See Application-Note AN-877:
29  *   https://www.analog.com/media/en/technical-documentation/application-notes/AN-877.pdf
30  */
31 
32 #define AN877_ADC_REG_CHIP_PORT_CONF		0x00
33 #define AN877_ADC_REG_CHIP_ID			0x01
34 #define AN877_ADC_REG_CHIP_GRADE		0x02
35 #define AN877_ADC_REG_CHAN_INDEX		0x05
36 #define AN877_ADC_REG_TRANSFER			0xFF
37 #define AN877_ADC_REG_MODES			0x08
38 #define AN877_ADC_REG_TEST_IO			0x0D
39 #define AN877_ADC_REG_ADC_INPUT			0x0F
40 #define AN877_ADC_REG_OFFSET			0x10
41 #define AN877_ADC_REG_OUTPUT_MODE		0x14
42 #define AN877_ADC_REG_OUTPUT_ADJUST		0x15
43 #define AN877_ADC_REG_OUTPUT_PHASE		0x16
44 #define AN877_ADC_REG_OUTPUT_DELAY		0x17
45 #define AN877_ADC_REG_VREF			0x18
46 #define AN877_ADC_REG_ANALOG_INPUT		0x2C
47 
48 /* AN877_ADC_REG_TEST_IO */
49 #define AN877_ADC_TESTMODE_OFF			0x0
50 #define AN877_ADC_TESTMODE_MIDSCALE_SHORT	0x1
51 #define AN877_ADC_TESTMODE_POS_FULLSCALE	0x2
52 #define AN877_ADC_TESTMODE_NEG_FULLSCALE	0x3
53 #define AN877_ADC_TESTMODE_ALT_CHECKERBOARD	0x4
54 #define AN877_ADC_TESTMODE_PN23_SEQ		0x5
55 #define AN877_ADC_TESTMODE_PN9_SEQ		0x6
56 #define AN877_ADC_TESTMODE_ONE_ZERO_TOGGLE	0x7
57 #define AN877_ADC_TESTMODE_USER			0x8
58 #define AN877_ADC_TESTMODE_BIT_TOGGLE		0x9
59 #define AN877_ADC_TESTMODE_SYNC			0xA
60 #define AN877_ADC_TESTMODE_ONE_BIT_HIGH		0xB
61 #define AN877_ADC_TESTMODE_MIXED_BIT_FREQUENCY	0xC
62 #define AN877_ADC_TESTMODE_RAMP			0xF
63 
64 /* AN877_ADC_REG_TRANSFER */
65 #define AN877_ADC_TRANSFER_SYNC			0x1
66 
67 /* AN877_ADC_REG_OUTPUT_MODE */
68 #define AN877_ADC_OUTPUT_MODE_OFFSET_BINARY	0x0
69 #define AN877_ADC_OUTPUT_MODE_TWOS_COMPLEMENT	0x1
70 #define AN877_ADC_OUTPUT_MODE_GRAY_CODE		0x2
71 
72 /* AN877_ADC_REG_OUTPUT_PHASE */
73 #define AN877_ADC_OUTPUT_EVEN_ODD_MODE_EN	0x20
74 #define AN877_ADC_INVERT_DCO_CLK		0x80
75 
76 /* AN877_ADC_REG_OUTPUT_DELAY */
77 #define AN877_ADC_DCO_DELAY_ENABLE		0x80
78 
79 /*
80  * Analog Devices AD9265 16-Bit, 125/105/80 MSPS ADC
81  */
82 
83 #define CHIPID_AD9265			0x64
84 #define AD9265_DEF_OUTPUT_MODE		0x40
85 #define AD9265_REG_VREF_MASK		0xC0
86 
87 /*
88  * Analog Devices AD9434 12-Bit, 370/500 MSPS ADC
89  */
90 
91 #define CHIPID_AD9434			0x6A
92 #define AD9434_DEF_OUTPUT_MODE		0x00
93 #define AD9434_REG_VREF_MASK		0xC0
94 
95 /*
96  * Analog Devices AD9467 16-Bit, 200/250 MSPS ADC
97  */
98 
99 #define CHIPID_AD9467			0x50
100 #define AD9467_DEF_OUTPUT_MODE		0x08
101 #define AD9467_REG_VREF_MASK		0x0F
102 
103 enum {
104 	ID_AD9265,
105 	ID_AD9434,
106 	ID_AD9467,
107 };
108 
109 struct ad9467_chip_info {
110 	struct adi_axi_adc_chip_info	axi_adc_info;
111 	unsigned int			default_output_mode;
112 	unsigned int			vref_mask;
113 };
114 
115 #define to_ad9467_chip_info(_info)	\
116 	container_of(_info, struct ad9467_chip_info, axi_adc_info)
117 
118 struct ad9467_state {
119 	struct spi_device		*spi;
120 	struct clk			*clk;
121 	unsigned int			output_mode;
122 
123 	struct gpio_desc		*pwrdown_gpio;
124 	struct gpio_desc		*reset_gpio;
125 };
126 
127 static int ad9467_spi_read(struct spi_device *spi, unsigned int reg)
128 {
129 	unsigned char tbuf[2], rbuf[1];
130 	int ret;
131 
132 	tbuf[0] = 0x80 | (reg >> 8);
133 	tbuf[1] = reg & 0xFF;
134 
135 	ret = spi_write_then_read(spi,
136 				  tbuf, ARRAY_SIZE(tbuf),
137 				  rbuf, ARRAY_SIZE(rbuf));
138 
139 	if (ret < 0)
140 		return ret;
141 
142 	return rbuf[0];
143 }
144 
145 static int ad9467_spi_write(struct spi_device *spi, unsigned int reg,
146 			    unsigned int val)
147 {
148 	unsigned char buf[3];
149 
150 	buf[0] = reg >> 8;
151 	buf[1] = reg & 0xFF;
152 	buf[2] = val;
153 
154 	return spi_write(spi, buf, ARRAY_SIZE(buf));
155 }
156 
157 static int ad9467_reg_access(struct adi_axi_adc_conv *conv, unsigned int reg,
158 			     unsigned int writeval, unsigned int *readval)
159 {
160 	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
161 	struct spi_device *spi = st->spi;
162 	int ret;
163 
164 	if (readval == NULL) {
165 		ret = ad9467_spi_write(spi, reg, writeval);
166 		ad9467_spi_write(spi, AN877_ADC_REG_TRANSFER,
167 				 AN877_ADC_TRANSFER_SYNC);
168 		return ret;
169 	}
170 
171 	ret = ad9467_spi_read(spi, reg);
172 	if (ret < 0)
173 		return ret;
174 	*readval = ret;
175 
176 	return 0;
177 }
178 
179 static const unsigned int ad9265_scale_table[][2] = {
180 	{1250, 0x00}, {1500, 0x40}, {1750, 0x80}, {2000, 0xC0},
181 };
182 
183 static const unsigned int ad9434_scale_table[][2] = {
184 	{1600, 0x1C}, {1580, 0x1D}, {1550, 0x1E}, {1520, 0x1F}, {1500, 0x00},
185 	{1470, 0x01}, {1440, 0x02}, {1420, 0x03}, {1390, 0x04}, {1360, 0x05},
186 	{1340, 0x06}, {1310, 0x07}, {1280, 0x08}, {1260, 0x09}, {1230, 0x0A},
187 	{1200, 0x0B}, {1180, 0x0C},
188 };
189 
190 static const unsigned int ad9467_scale_table[][2] = {
191 	{2000, 0}, {2100, 6}, {2200, 7},
192 	{2300, 8}, {2400, 9}, {2500, 10},
193 };
194 
195 static void __ad9467_get_scale(struct adi_axi_adc_conv *conv, int index,
196 			       unsigned int *val, unsigned int *val2)
197 {
198 	const struct adi_axi_adc_chip_info *info = conv->chip_info;
199 	const struct iio_chan_spec *chan = &info->channels[0];
200 	unsigned int tmp;
201 
202 	tmp = (info->scale_table[index][0] * 1000000ULL) >>
203 			chan->scan_type.realbits;
204 	*val = tmp / 1000000;
205 	*val2 = tmp % 1000000;
206 }
207 
208 #define AD9467_CHAN(_chan, _si, _bits, _sign)				\
209 {									\
210 	.type = IIO_VOLTAGE,						\
211 	.indexed = 1,							\
212 	.channel = _chan,						\
213 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |		\
214 		BIT(IIO_CHAN_INFO_SAMP_FREQ),				\
215 	.scan_index = _si,						\
216 	.scan_type = {							\
217 		.sign = _sign,						\
218 		.realbits = _bits,					\
219 		.storagebits = 16,					\
220 	},								\
221 }
222 
223 static const struct iio_chan_spec ad9434_channels[] = {
224 	AD9467_CHAN(0, 0, 12, 'S'),
225 };
226 
227 static const struct iio_chan_spec ad9467_channels[] = {
228 	AD9467_CHAN(0, 0, 16, 'S'),
229 };
230 
231 static const struct ad9467_chip_info ad9467_chip_tbl[] = {
232 	[ID_AD9265] = {
233 		.axi_adc_info = {
234 			.id = CHIPID_AD9265,
235 			.max_rate = 125000000UL,
236 			.scale_table = ad9265_scale_table,
237 			.num_scales = ARRAY_SIZE(ad9265_scale_table),
238 			.channels = ad9467_channels,
239 			.num_channels = ARRAY_SIZE(ad9467_channels),
240 		},
241 		.default_output_mode = AD9265_DEF_OUTPUT_MODE,
242 		.vref_mask = AD9265_REG_VREF_MASK,
243 	},
244 	[ID_AD9434] = {
245 		.axi_adc_info = {
246 			.id = CHIPID_AD9434,
247 			.max_rate = 500000000UL,
248 			.scale_table = ad9434_scale_table,
249 			.num_scales = ARRAY_SIZE(ad9434_scale_table),
250 			.channels = ad9434_channels,
251 			.num_channels = ARRAY_SIZE(ad9434_channels),
252 		},
253 		.default_output_mode = AD9434_DEF_OUTPUT_MODE,
254 		.vref_mask = AD9434_REG_VREF_MASK,
255 	},
256 	[ID_AD9467] = {
257 		.axi_adc_info = {
258 			.id = CHIPID_AD9467,
259 			.max_rate = 250000000UL,
260 			.scale_table = ad9467_scale_table,
261 			.num_scales = ARRAY_SIZE(ad9467_scale_table),
262 			.channels = ad9467_channels,
263 			.num_channels = ARRAY_SIZE(ad9467_channels),
264 		},
265 		.default_output_mode = AD9467_DEF_OUTPUT_MODE,
266 		.vref_mask = AD9467_REG_VREF_MASK,
267 	},
268 };
269 
270 static int ad9467_get_scale(struct adi_axi_adc_conv *conv, int *val, int *val2)
271 {
272 	const struct adi_axi_adc_chip_info *info = conv->chip_info;
273 	const struct ad9467_chip_info *info1 = to_ad9467_chip_info(info);
274 	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
275 	unsigned int i, vref_val;
276 
277 	vref_val = ad9467_spi_read(st->spi, AN877_ADC_REG_VREF);
278 
279 	vref_val &= info1->vref_mask;
280 
281 	for (i = 0; i < info->num_scales; i++) {
282 		if (vref_val == info->scale_table[i][1])
283 			break;
284 	}
285 
286 	if (i == info->num_scales)
287 		return -ERANGE;
288 
289 	__ad9467_get_scale(conv, i, val, val2);
290 
291 	return IIO_VAL_INT_PLUS_MICRO;
292 }
293 
294 static int ad9467_set_scale(struct adi_axi_adc_conv *conv, int val, int val2)
295 {
296 	const struct adi_axi_adc_chip_info *info = conv->chip_info;
297 	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
298 	unsigned int scale_val[2];
299 	unsigned int i;
300 
301 	if (val != 0)
302 		return -EINVAL;
303 
304 	for (i = 0; i < info->num_scales; i++) {
305 		__ad9467_get_scale(conv, i, &scale_val[0], &scale_val[1]);
306 		if (scale_val[0] != val || scale_val[1] != val2)
307 			continue;
308 
309 		ad9467_spi_write(st->spi, AN877_ADC_REG_VREF,
310 				 info->scale_table[i][1]);
311 		ad9467_spi_write(st->spi, AN877_ADC_REG_TRANSFER,
312 				 AN877_ADC_TRANSFER_SYNC);
313 		return 0;
314 	}
315 
316 	return -EINVAL;
317 }
318 
319 static int ad9467_read_raw(struct adi_axi_adc_conv *conv,
320 			   struct iio_chan_spec const *chan,
321 			   int *val, int *val2, long m)
322 {
323 	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
324 
325 	switch (m) {
326 	case IIO_CHAN_INFO_SCALE:
327 		return ad9467_get_scale(conv, val, val2);
328 	case IIO_CHAN_INFO_SAMP_FREQ:
329 		*val = clk_get_rate(st->clk);
330 
331 		return IIO_VAL_INT;
332 	default:
333 		return -EINVAL;
334 	}
335 }
336 
337 static int ad9467_write_raw(struct adi_axi_adc_conv *conv,
338 			    struct iio_chan_spec const *chan,
339 			    int val, int val2, long mask)
340 {
341 	const struct adi_axi_adc_chip_info *info = conv->chip_info;
342 	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
343 	long r_clk;
344 
345 	switch (mask) {
346 	case IIO_CHAN_INFO_SCALE:
347 		return ad9467_set_scale(conv, val, val2);
348 	case IIO_CHAN_INFO_SAMP_FREQ:
349 		r_clk = clk_round_rate(st->clk, val);
350 		if (r_clk < 0 || r_clk > info->max_rate) {
351 			dev_warn(&st->spi->dev,
352 				 "Error setting ADC sample rate %ld", r_clk);
353 			return -EINVAL;
354 		}
355 
356 		return clk_set_rate(st->clk, r_clk);
357 	default:
358 		return -EINVAL;
359 	}
360 }
361 
362 static int ad9467_outputmode_set(struct spi_device *spi, unsigned int mode)
363 {
364 	int ret;
365 
366 	ret = ad9467_spi_write(spi, AN877_ADC_REG_OUTPUT_MODE, mode);
367 	if (ret < 0)
368 		return ret;
369 
370 	return ad9467_spi_write(spi, AN877_ADC_REG_TRANSFER,
371 				AN877_ADC_TRANSFER_SYNC);
372 }
373 
374 static int ad9467_preenable_setup(struct adi_axi_adc_conv *conv)
375 {
376 	struct ad9467_state *st = adi_axi_adc_conv_priv(conv);
377 
378 	return ad9467_outputmode_set(st->spi, st->output_mode);
379 }
380 
381 static void ad9467_clk_disable(void *data)
382 {
383 	struct ad9467_state *st = data;
384 
385 	clk_disable_unprepare(st->clk);
386 }
387 
388 static int ad9467_probe(struct spi_device *spi)
389 {
390 	const struct ad9467_chip_info *info;
391 	struct adi_axi_adc_conv *conv;
392 	struct ad9467_state *st;
393 	unsigned int id;
394 	int ret;
395 
396 	info = of_device_get_match_data(&spi->dev);
397 	if (!info)
398 		return -ENODEV;
399 
400 	conv = devm_adi_axi_adc_conv_register(&spi->dev, sizeof(*st));
401 	if (IS_ERR(conv))
402 		return PTR_ERR(conv);
403 
404 	st = adi_axi_adc_conv_priv(conv);
405 	st->spi = spi;
406 
407 	st->clk = devm_clk_get(&spi->dev, "adc-clk");
408 	if (IS_ERR(st->clk))
409 		return PTR_ERR(st->clk);
410 
411 	ret = clk_prepare_enable(st->clk);
412 	if (ret < 0)
413 		return ret;
414 
415 	ret = devm_add_action_or_reset(&spi->dev, ad9467_clk_disable, st);
416 	if (ret)
417 		return ret;
418 
419 	st->pwrdown_gpio = devm_gpiod_get_optional(&spi->dev, "powerdown",
420 						   GPIOD_OUT_LOW);
421 	if (IS_ERR(st->pwrdown_gpio))
422 		return PTR_ERR(st->pwrdown_gpio);
423 
424 	st->reset_gpio = devm_gpiod_get_optional(&spi->dev, "reset",
425 						 GPIOD_OUT_LOW);
426 	if (IS_ERR(st->reset_gpio))
427 		return PTR_ERR(st->reset_gpio);
428 
429 	if (st->reset_gpio) {
430 		udelay(1);
431 		ret = gpiod_direction_output(st->reset_gpio, 1);
432 		if (ret)
433 			return ret;
434 		mdelay(10);
435 	}
436 
437 	spi_set_drvdata(spi, st);
438 
439 	conv->chip_info = &info->axi_adc_info;
440 
441 	id = ad9467_spi_read(spi, AN877_ADC_REG_CHIP_ID);
442 	if (id != conv->chip_info->id) {
443 		dev_err(&spi->dev, "Mismatch CHIP_ID, got 0x%X, expected 0x%X\n",
444 			id, conv->chip_info->id);
445 		return -ENODEV;
446 	}
447 
448 	conv->reg_access = ad9467_reg_access;
449 	conv->write_raw = ad9467_write_raw;
450 	conv->read_raw = ad9467_read_raw;
451 	conv->preenable_setup = ad9467_preenable_setup;
452 
453 	st->output_mode = info->default_output_mode |
454 			  AN877_ADC_OUTPUT_MODE_TWOS_COMPLEMENT;
455 
456 	return 0;
457 }
458 
459 static const struct of_device_id ad9467_of_match[] = {
460 	{ .compatible = "adi,ad9265", .data = &ad9467_chip_tbl[ID_AD9265], },
461 	{ .compatible = "adi,ad9434", .data = &ad9467_chip_tbl[ID_AD9434], },
462 	{ .compatible = "adi,ad9467", .data = &ad9467_chip_tbl[ID_AD9467], },
463 	{}
464 };
465 MODULE_DEVICE_TABLE(of, ad9467_of_match);
466 
467 static struct spi_driver ad9467_driver = {
468 	.driver = {
469 		.name = "ad9467",
470 		.of_match_table = ad9467_of_match,
471 	},
472 	.probe = ad9467_probe,
473 };
474 module_spi_driver(ad9467_driver);
475 
476 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
477 MODULE_DESCRIPTION("Analog Devices AD9467 ADC driver");
478 MODULE_LICENSE("GPL v2");
479