xref: /openbmc/linux/drivers/iio/adc/ad4130.c (revision cc698db4)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2022 Analog Devices, Inc.
4  * Author: Cosmin Tanislav <cosmin.tanislav@analog.com>
5  */
6 
7 #include <linux/bitfield.h>
8 #include <linux/bitops.h>
9 #include <linux/clk.h>
10 #include <linux/clk-provider.h>
11 #include <linux/delay.h>
12 #include <linux/device.h>
13 #include <linux/err.h>
14 #include <linux/gpio/driver.h>
15 #include <linux/interrupt.h>
16 #include <linux/irq.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/property.h>
20 #include <linux/regmap.h>
21 #include <linux/regulator/consumer.h>
22 #include <linux/spi/spi.h>
23 #include <linux/units.h>
24 
25 #include <asm/div64.h>
26 #include <asm/unaligned.h>
27 
28 #include <linux/iio/buffer.h>
29 #include <linux/iio/iio.h>
30 #include <linux/iio/kfifo_buf.h>
31 #include <linux/iio/sysfs.h>
32 
33 #define AD4130_NAME				"ad4130"
34 
35 #define AD4130_COMMS_READ_MASK			BIT(6)
36 
37 #define AD4130_STATUS_REG			0x00
38 
39 #define AD4130_ADC_CONTROL_REG			0x01
40 #define AD4130_ADC_CONTROL_BIPOLAR_MASK		BIT(14)
41 #define AD4130_ADC_CONTROL_INT_REF_VAL_MASK	BIT(13)
42 #define AD4130_INT_REF_2_5V			2500000
43 #define AD4130_INT_REF_1_25V			1250000
44 #define AD4130_ADC_CONTROL_CSB_EN_MASK		BIT(9)
45 #define AD4130_ADC_CONTROL_INT_REF_EN_MASK	BIT(8)
46 #define AD4130_ADC_CONTROL_MODE_MASK		GENMASK(5, 2)
47 #define AD4130_ADC_CONTROL_MCLK_SEL_MASK	GENMASK(1, 0)
48 #define AD4130_MCLK_FREQ_76_8KHZ		76800
49 #define AD4130_MCLK_FREQ_153_6KHZ		153600
50 
51 #define AD4130_DATA_REG				0x02
52 
53 #define AD4130_IO_CONTROL_REG			0x03
54 #define AD4130_IO_CONTROL_INT_PIN_SEL_MASK	GENMASK(9, 8)
55 #define AD4130_IO_CONTROL_GPIO_DATA_MASK	GENMASK(7, 4)
56 #define AD4130_IO_CONTROL_GPIO_CTRL_MASK	GENMASK(3, 0)
57 
58 #define AD4130_VBIAS_REG			0x04
59 
60 #define AD4130_ID_REG				0x05
61 
62 #define AD4130_ERROR_REG			0x06
63 
64 #define AD4130_ERROR_EN_REG			0x07
65 
66 #define AD4130_MCLK_COUNT_REG			0x08
67 
68 #define AD4130_CHANNEL_X_REG(x)			(0x09 + (x))
69 #define AD4130_CHANNEL_EN_MASK			BIT(23)
70 #define AD4130_CHANNEL_SETUP_MASK		GENMASK(22, 20)
71 #define AD4130_CHANNEL_AINP_MASK		GENMASK(17, 13)
72 #define AD4130_CHANNEL_AINM_MASK		GENMASK(12, 8)
73 #define AD4130_CHANNEL_IOUT1_MASK		GENMASK(7, 4)
74 #define AD4130_CHANNEL_IOUT2_MASK		GENMASK(3, 0)
75 
76 #define AD4130_CONFIG_X_REG(x)			(0x19 + (x))
77 #define AD4130_CONFIG_IOUT1_VAL_MASK		GENMASK(15, 13)
78 #define AD4130_CONFIG_IOUT2_VAL_MASK		GENMASK(12, 10)
79 #define AD4130_CONFIG_BURNOUT_MASK		GENMASK(9, 8)
80 #define AD4130_CONFIG_REF_BUFP_MASK		BIT(7)
81 #define AD4130_CONFIG_REF_BUFM_MASK		BIT(6)
82 #define AD4130_CONFIG_REF_SEL_MASK		GENMASK(5, 4)
83 #define AD4130_CONFIG_PGA_MASK			GENMASK(3, 1)
84 
85 #define AD4130_FILTER_X_REG(x)			(0x21 + (x))
86 #define AD4130_FILTER_MODE_MASK			GENMASK(15, 12)
87 #define AD4130_FILTER_SELECT_MASK		GENMASK(10, 0)
88 #define AD4130_FILTER_SELECT_MIN		1
89 
90 #define AD4130_OFFSET_X_REG(x)			(0x29 + (x))
91 
92 #define AD4130_GAIN_X_REG(x)			(0x31 + (x))
93 
94 #define AD4130_MISC_REG				0x39
95 
96 #define AD4130_FIFO_CONTROL_REG			0x3a
97 #define AD4130_FIFO_CONTROL_HEADER_MASK		BIT(18)
98 #define AD4130_FIFO_CONTROL_MODE_MASK		GENMASK(17, 16)
99 #define AD4130_FIFO_CONTROL_WM_INT_EN_MASK	BIT(9)
100 #define AD4130_FIFO_CONTROL_WM_MASK		GENMASK(7, 0)
101 #define AD4130_WATERMARK_256			0
102 
103 #define AD4130_FIFO_STATUS_REG			0x3b
104 
105 #define AD4130_FIFO_THRESHOLD_REG		0x3c
106 
107 #define AD4130_FIFO_DATA_REG			0x3d
108 #define AD4130_FIFO_SIZE			256
109 #define AD4130_FIFO_MAX_SAMPLE_SIZE		3
110 
111 #define AD4130_MAX_ANALOG_PINS			16
112 #define AD4130_MAX_CHANNELS			16
113 #define AD4130_MAX_DIFF_INPUTS			30
114 #define AD4130_MAX_GPIOS			4
115 #define AD4130_MAX_ODR				2400
116 #define AD4130_MAX_PGA				8
117 #define AD4130_MAX_SETUPS			8
118 
119 #define AD4130_AIN2_P1				0x2
120 #define AD4130_AIN3_P2				0x3
121 
122 #define AD4130_RESET_BUF_SIZE			8
123 #define AD4130_RESET_SLEEP_US			(160 * MICRO / AD4130_MCLK_FREQ_76_8KHZ)
124 
125 #define AD4130_INVALID_SLOT			-1
126 
127 static const unsigned int ad4130_reg_size[] = {
128 	[AD4130_STATUS_REG] = 1,
129 	[AD4130_ADC_CONTROL_REG] = 2,
130 	[AD4130_DATA_REG] = 3,
131 	[AD4130_IO_CONTROL_REG] = 2,
132 	[AD4130_VBIAS_REG] = 2,
133 	[AD4130_ID_REG] = 1,
134 	[AD4130_ERROR_REG] = 2,
135 	[AD4130_ERROR_EN_REG] = 2,
136 	[AD4130_MCLK_COUNT_REG] = 1,
137 	[AD4130_CHANNEL_X_REG(0) ... AD4130_CHANNEL_X_REG(AD4130_MAX_CHANNELS - 1)] = 3,
138 	[AD4130_CONFIG_X_REG(0) ... AD4130_CONFIG_X_REG(AD4130_MAX_SETUPS - 1)] = 2,
139 	[AD4130_FILTER_X_REG(0) ... AD4130_FILTER_X_REG(AD4130_MAX_SETUPS - 1)] = 3,
140 	[AD4130_OFFSET_X_REG(0) ... AD4130_OFFSET_X_REG(AD4130_MAX_SETUPS - 1)] = 3,
141 	[AD4130_GAIN_X_REG(0) ... AD4130_GAIN_X_REG(AD4130_MAX_SETUPS - 1)] = 3,
142 	[AD4130_MISC_REG] = 2,
143 	[AD4130_FIFO_CONTROL_REG] = 3,
144 	[AD4130_FIFO_STATUS_REG] = 1,
145 	[AD4130_FIFO_THRESHOLD_REG] = 3,
146 	[AD4130_FIFO_DATA_REG] = 3,
147 };
148 
149 enum ad4130_int_ref_val {
150 	AD4130_INT_REF_VAL_2_5V,
151 	AD4130_INT_REF_VAL_1_25V,
152 };
153 
154 enum ad4130_mclk_sel {
155 	AD4130_MCLK_76_8KHZ,
156 	AD4130_MCLK_76_8KHZ_OUT,
157 	AD4130_MCLK_76_8KHZ_EXT,
158 	AD4130_MCLK_153_6KHZ_EXT,
159 };
160 
161 enum ad4130_int_pin_sel {
162 	AD4130_INT_PIN_INT,
163 	AD4130_INT_PIN_CLK,
164 	AD4130_INT_PIN_P2,
165 	AD4130_INT_PIN_DOUT,
166 };
167 
168 enum ad4130_iout {
169 	AD4130_IOUT_OFF,
170 	AD4130_IOUT_10000NA,
171 	AD4130_IOUT_20000NA,
172 	AD4130_IOUT_50000NA,
173 	AD4130_IOUT_100000NA,
174 	AD4130_IOUT_150000NA,
175 	AD4130_IOUT_200000NA,
176 	AD4130_IOUT_100NA,
177 	AD4130_IOUT_MAX
178 };
179 
180 enum ad4130_burnout {
181 	AD4130_BURNOUT_OFF,
182 	AD4130_BURNOUT_500NA,
183 	AD4130_BURNOUT_2000NA,
184 	AD4130_BURNOUT_4000NA,
185 	AD4130_BURNOUT_MAX
186 };
187 
188 enum ad4130_ref_sel {
189 	AD4130_REF_REFIN1,
190 	AD4130_REF_REFIN2,
191 	AD4130_REF_REFOUT_AVSS,
192 	AD4130_REF_AVDD_AVSS,
193 	AD4130_REF_SEL_MAX
194 };
195 
196 enum ad4130_fifo_mode {
197 	AD4130_FIFO_MODE_DISABLED = 0b00,
198 	AD4130_FIFO_MODE_WM = 0b01,
199 };
200 
201 enum ad4130_mode {
202 	AD4130_MODE_CONTINUOUS = 0b0000,
203 	AD4130_MODE_IDLE = 0b0100,
204 };
205 
206 enum ad4130_filter_mode {
207 	AD4130_FILTER_SINC4,
208 	AD4130_FILTER_SINC4_SINC1,
209 	AD4130_FILTER_SINC3,
210 	AD4130_FILTER_SINC3_REJ60,
211 	AD4130_FILTER_SINC3_SINC1,
212 	AD4130_FILTER_SINC3_PF1,
213 	AD4130_FILTER_SINC3_PF2,
214 	AD4130_FILTER_SINC3_PF3,
215 	AD4130_FILTER_SINC3_PF4,
216 };
217 
218 enum ad4130_pin_function {
219 	AD4130_PIN_FN_NONE,
220 	AD4130_PIN_FN_SPECIAL = BIT(0),
221 	AD4130_PIN_FN_DIFF = BIT(1),
222 	AD4130_PIN_FN_EXCITATION = BIT(2),
223 	AD4130_PIN_FN_VBIAS = BIT(3),
224 };
225 
226 struct ad4130_setup_info {
227 	unsigned int			iout0_val;
228 	unsigned int			iout1_val;
229 	unsigned int			burnout;
230 	unsigned int			pga;
231 	unsigned int			fs;
232 	u32				ref_sel;
233 	enum ad4130_filter_mode		filter_mode;
234 	bool				ref_bufp;
235 	bool				ref_bufm;
236 };
237 
238 struct ad4130_slot_info {
239 	struct ad4130_setup_info	setup;
240 	unsigned int			enabled_channels;
241 	unsigned int			channels;
242 };
243 
244 struct ad4130_chan_info {
245 	struct ad4130_setup_info	setup;
246 	u32				iout0;
247 	u32				iout1;
248 	int				slot;
249 	bool				enabled;
250 	bool				initialized;
251 };
252 
253 struct ad4130_filter_config {
254 	enum ad4130_filter_mode		filter_mode;
255 	unsigned int			odr_div;
256 	unsigned int			fs_max;
257 	enum iio_available_type		samp_freq_avail_type;
258 	int				samp_freq_avail_len;
259 	int				samp_freq_avail[3][2];
260 };
261 
262 struct ad4130_state {
263 	struct regmap			*regmap;
264 	struct spi_device		*spi;
265 	struct clk			*mclk;
266 	struct regulator_bulk_data	regulators[4];
267 	u32				irq_trigger;
268 	u32				inv_irq_trigger;
269 
270 	/*
271 	 * Synchronize access to members the of driver state, and ensure
272 	 * atomicity of consecutive regmap operations.
273 	 */
274 	struct mutex			lock;
275 	struct completion		completion;
276 
277 	struct iio_chan_spec		chans[AD4130_MAX_CHANNELS];
278 	struct ad4130_chan_info		chans_info[AD4130_MAX_CHANNELS];
279 	struct ad4130_slot_info		slots_info[AD4130_MAX_SETUPS];
280 	enum ad4130_pin_function	pins_fn[AD4130_MAX_ANALOG_PINS];
281 	u32				vbias_pins[AD4130_MAX_ANALOG_PINS];
282 	u32				num_vbias_pins;
283 	int				scale_tbls[AD4130_REF_SEL_MAX][AD4130_MAX_PGA][2];
284 	struct gpio_chip		gc;
285 	struct clk_hw			int_clk_hw;
286 
287 	u32			int_pin_sel;
288 	u32			int_ref_uv;
289 	u32			mclk_sel;
290 	bool			int_ref_en;
291 	bool			bipolar;
292 
293 	unsigned int		num_enabled_channels;
294 	unsigned int		effective_watermark;
295 	unsigned int		watermark;
296 
297 	struct spi_message	fifo_msg;
298 	struct spi_transfer	fifo_xfer[2];
299 
300 	/*
301 	 * DMA (thus cache coherency maintenance) requires any transfer
302 	 * buffers to live in their own cache lines. As the use of these
303 	 * buffers is synchronous, all of the buffers used for DMA in this
304 	 * driver may share a cache line.
305 	 */
306 	u8			reset_buf[AD4130_RESET_BUF_SIZE] __aligned(IIO_DMA_MINALIGN);
307 	u8			reg_write_tx_buf[4];
308 	u8			reg_read_tx_buf[1];
309 	u8			reg_read_rx_buf[3];
310 	u8			fifo_tx_buf[2];
311 	u8			fifo_rx_buf[AD4130_FIFO_SIZE *
312 					    AD4130_FIFO_MAX_SAMPLE_SIZE];
313 };
314 
315 static const char * const ad4130_int_pin_names[] = {
316 	[AD4130_INT_PIN_INT] = "int",
317 	[AD4130_INT_PIN_CLK] = "clk",
318 	[AD4130_INT_PIN_P2] = "p2",
319 	[AD4130_INT_PIN_DOUT] = "dout",
320 };
321 
322 static const unsigned int ad4130_iout_current_na_tbl[AD4130_IOUT_MAX] = {
323 	[AD4130_IOUT_OFF] = 0,
324 	[AD4130_IOUT_100NA] = 100,
325 	[AD4130_IOUT_10000NA] = 10000,
326 	[AD4130_IOUT_20000NA] = 20000,
327 	[AD4130_IOUT_50000NA] = 50000,
328 	[AD4130_IOUT_100000NA] = 100000,
329 	[AD4130_IOUT_150000NA] = 150000,
330 	[AD4130_IOUT_200000NA] = 200000,
331 };
332 
333 static const unsigned int ad4130_burnout_current_na_tbl[AD4130_BURNOUT_MAX] = {
334 	[AD4130_BURNOUT_OFF] = 0,
335 	[AD4130_BURNOUT_500NA] = 500,
336 	[AD4130_BURNOUT_2000NA] = 2000,
337 	[AD4130_BURNOUT_4000NA] = 4000,
338 };
339 
340 #define AD4130_VARIABLE_ODR_CONFIG(_filter_mode, _odr_div, _fs_max)	\
341 {									\
342 		.filter_mode = (_filter_mode),				\
343 		.odr_div = (_odr_div),					\
344 		.fs_max = (_fs_max),					\
345 		.samp_freq_avail_type = IIO_AVAIL_RANGE,		\
346 		.samp_freq_avail = {					\
347 			{ AD4130_MAX_ODR, (_odr_div) * (_fs_max) },	\
348 			{ AD4130_MAX_ODR, (_odr_div) * (_fs_max) },	\
349 			{ AD4130_MAX_ODR, (_odr_div) },			\
350 		},							\
351 }
352 
353 #define AD4130_FIXED_ODR_CONFIG(_filter_mode, _odr_div)			\
354 {									\
355 		.filter_mode = (_filter_mode),				\
356 		.odr_div = (_odr_div),					\
357 		.fs_max = AD4130_FILTER_SELECT_MIN,			\
358 		.samp_freq_avail_type = IIO_AVAIL_LIST,			\
359 		.samp_freq_avail_len = 1,				\
360 		.samp_freq_avail = {					\
361 			{ AD4130_MAX_ODR, (_odr_div) },			\
362 		},							\
363 }
364 
365 static const struct ad4130_filter_config ad4130_filter_configs[] = {
366 	AD4130_VARIABLE_ODR_CONFIG(AD4130_FILTER_SINC4,       1,  10),
367 	AD4130_VARIABLE_ODR_CONFIG(AD4130_FILTER_SINC4_SINC1, 11, 10),
368 	AD4130_VARIABLE_ODR_CONFIG(AD4130_FILTER_SINC3,       1,  2047),
369 	AD4130_VARIABLE_ODR_CONFIG(AD4130_FILTER_SINC3_REJ60, 1,  2047),
370 	AD4130_VARIABLE_ODR_CONFIG(AD4130_FILTER_SINC3_SINC1, 10, 2047),
371 	AD4130_FIXED_ODR_CONFIG(AD4130_FILTER_SINC3_PF1,      92),
372 	AD4130_FIXED_ODR_CONFIG(AD4130_FILTER_SINC3_PF2,      100),
373 	AD4130_FIXED_ODR_CONFIG(AD4130_FILTER_SINC3_PF3,      124),
374 	AD4130_FIXED_ODR_CONFIG(AD4130_FILTER_SINC3_PF4,      148),
375 };
376 
377 static const char * const ad4130_filter_modes_str[] = {
378 	[AD4130_FILTER_SINC4] = "sinc4",
379 	[AD4130_FILTER_SINC4_SINC1] = "sinc4+sinc1",
380 	[AD4130_FILTER_SINC3] = "sinc3",
381 	[AD4130_FILTER_SINC3_REJ60] = "sinc3+rej60",
382 	[AD4130_FILTER_SINC3_SINC1] = "sinc3+sinc1",
383 	[AD4130_FILTER_SINC3_PF1] = "sinc3+pf1",
384 	[AD4130_FILTER_SINC3_PF2] = "sinc3+pf2",
385 	[AD4130_FILTER_SINC3_PF3] = "sinc3+pf3",
386 	[AD4130_FILTER_SINC3_PF4] = "sinc3+pf4",
387 };
388 
389 static int ad4130_get_reg_size(struct ad4130_state *st, unsigned int reg,
390 			       unsigned int *size)
391 {
392 	if (reg >= ARRAY_SIZE(ad4130_reg_size))
393 		return -EINVAL;
394 
395 	*size = ad4130_reg_size[reg];
396 
397 	return 0;
398 }
399 
400 static unsigned int ad4130_data_reg_size(struct ad4130_state *st)
401 {
402 	unsigned int data_reg_size;
403 	int ret;
404 
405 	ret = ad4130_get_reg_size(st, AD4130_DATA_REG, &data_reg_size);
406 	if (ret)
407 		return 0;
408 
409 	return data_reg_size;
410 }
411 
412 static unsigned int ad4130_resolution(struct ad4130_state *st)
413 {
414 	return ad4130_data_reg_size(st) * BITS_PER_BYTE;
415 }
416 
417 static int ad4130_reg_write(void *context, unsigned int reg, unsigned int val)
418 {
419 	struct ad4130_state *st = context;
420 	unsigned int size;
421 	int ret;
422 
423 	ret = ad4130_get_reg_size(st, reg, &size);
424 	if (ret)
425 		return ret;
426 
427 	st->reg_write_tx_buf[0] = reg;
428 
429 	switch (size) {
430 	case 3:
431 		put_unaligned_be24(val, &st->reg_write_tx_buf[1]);
432 		break;
433 	case 2:
434 		put_unaligned_be16(val, &st->reg_write_tx_buf[1]);
435 		break;
436 	case 1:
437 		st->reg_write_tx_buf[1] = val;
438 		break;
439 	default:
440 		return -EINVAL;
441 	}
442 
443 	return spi_write(st->spi, st->reg_write_tx_buf, size + 1);
444 }
445 
446 static int ad4130_reg_read(void *context, unsigned int reg, unsigned int *val)
447 {
448 	struct ad4130_state *st = context;
449 	struct spi_transfer t[] = {
450 		{
451 			.tx_buf = st->reg_read_tx_buf,
452 			.len = sizeof(st->reg_read_tx_buf),
453 		},
454 		{
455 			.rx_buf = st->reg_read_rx_buf,
456 		},
457 	};
458 	unsigned int size;
459 	int ret;
460 
461 	ret = ad4130_get_reg_size(st, reg, &size);
462 	if (ret)
463 		return ret;
464 
465 	st->reg_read_tx_buf[0] = AD4130_COMMS_READ_MASK | reg;
466 	t[1].len = size;
467 
468 	ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
469 	if (ret)
470 		return ret;
471 
472 	switch (size) {
473 	case 3:
474 		*val = get_unaligned_be24(st->reg_read_rx_buf);
475 		break;
476 	case 2:
477 		*val = get_unaligned_be16(st->reg_read_rx_buf);
478 		break;
479 	case 1:
480 		*val = st->reg_read_rx_buf[0];
481 		break;
482 	default:
483 		return -EINVAL;
484 	}
485 
486 	return 0;
487 }
488 
489 static const struct regmap_config ad4130_regmap_config = {
490 	.reg_read = ad4130_reg_read,
491 	.reg_write = ad4130_reg_write,
492 };
493 
494 static int ad4130_gpio_init_valid_mask(struct gpio_chip *gc,
495 				       unsigned long *valid_mask,
496 				       unsigned int ngpios)
497 {
498 	struct ad4130_state *st = gpiochip_get_data(gc);
499 	unsigned int i;
500 
501 	/*
502 	 * Output-only GPIO functionality is available on pins AIN2 through
503 	 * AIN5. If these pins are used for anything else, do not expose them.
504 	 */
505 	for (i = 0; i < ngpios; i++) {
506 		unsigned int pin = i + AD4130_AIN2_P1;
507 		bool valid = st->pins_fn[pin] == AD4130_PIN_FN_NONE;
508 
509 		__assign_bit(i, valid_mask, valid);
510 	}
511 
512 	return 0;
513 }
514 
515 static int ad4130_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
516 {
517 	return GPIO_LINE_DIRECTION_OUT;
518 }
519 
520 static void ad4130_gpio_set(struct gpio_chip *gc, unsigned int offset,
521 			    int value)
522 {
523 	struct ad4130_state *st = gpiochip_get_data(gc);
524 	unsigned int mask = FIELD_PREP(AD4130_IO_CONTROL_GPIO_DATA_MASK,
525 				       BIT(offset));
526 
527 	regmap_update_bits(st->regmap, AD4130_IO_CONTROL_REG, mask,
528 			   value ? mask : 0);
529 }
530 
531 static int ad4130_set_mode(struct ad4130_state *st, enum ad4130_mode mode)
532 {
533 	return regmap_update_bits(st->regmap, AD4130_ADC_CONTROL_REG,
534 				  AD4130_ADC_CONTROL_MODE_MASK,
535 				  FIELD_PREP(AD4130_ADC_CONTROL_MODE_MASK, mode));
536 }
537 
538 static int ad4130_set_watermark_interrupt_en(struct ad4130_state *st, bool en)
539 {
540 	return regmap_update_bits(st->regmap, AD4130_FIFO_CONTROL_REG,
541 				  AD4130_FIFO_CONTROL_WM_INT_EN_MASK,
542 				  FIELD_PREP(AD4130_FIFO_CONTROL_WM_INT_EN_MASK, en));
543 }
544 
545 static unsigned int ad4130_watermark_reg_val(unsigned int val)
546 {
547 	if (val == AD4130_FIFO_SIZE)
548 		val = AD4130_WATERMARK_256;
549 
550 	return val;
551 }
552 
553 static int ad4130_set_fifo_mode(struct ad4130_state *st,
554 				enum ad4130_fifo_mode mode)
555 {
556 	return regmap_update_bits(st->regmap, AD4130_FIFO_CONTROL_REG,
557 				  AD4130_FIFO_CONTROL_MODE_MASK,
558 				  FIELD_PREP(AD4130_FIFO_CONTROL_MODE_MASK, mode));
559 }
560 
561 static void ad4130_push_fifo_data(struct iio_dev *indio_dev)
562 {
563 	struct ad4130_state *st = iio_priv(indio_dev);
564 	unsigned int data_reg_size = ad4130_data_reg_size(st);
565 	unsigned int transfer_len = st->effective_watermark * data_reg_size;
566 	unsigned int set_size = st->num_enabled_channels * data_reg_size;
567 	unsigned int i;
568 	int ret;
569 
570 	st->fifo_tx_buf[1] = ad4130_watermark_reg_val(st->effective_watermark);
571 	st->fifo_xfer[1].len = transfer_len;
572 
573 	ret = spi_sync(st->spi, &st->fifo_msg);
574 	if (ret)
575 		return;
576 
577 	for (i = 0; i < transfer_len; i += set_size)
578 		iio_push_to_buffers(indio_dev, &st->fifo_rx_buf[i]);
579 }
580 
581 static irqreturn_t ad4130_irq_handler(int irq, void *private)
582 {
583 	struct iio_dev *indio_dev = private;
584 	struct ad4130_state *st = iio_priv(indio_dev);
585 
586 	if (iio_buffer_enabled(indio_dev))
587 		ad4130_push_fifo_data(indio_dev);
588 	else
589 		complete(&st->completion);
590 
591 	return IRQ_HANDLED;
592 }
593 
594 static int ad4130_find_slot(struct ad4130_state *st,
595 			    struct ad4130_setup_info *target_setup_info,
596 			    unsigned int *slot, bool *overwrite)
597 {
598 	unsigned int i;
599 
600 	*slot = AD4130_INVALID_SLOT;
601 	*overwrite = false;
602 
603 	for (i = 0; i < AD4130_MAX_SETUPS; i++) {
604 		struct ad4130_slot_info *slot_info = &st->slots_info[i];
605 
606 		/* Immediately accept a matching setup info. */
607 		if (!memcmp(target_setup_info, &slot_info->setup,
608 			    sizeof(*target_setup_info))) {
609 			*slot = i;
610 			return 0;
611 		}
612 
613 		/* Ignore all setups which are used by enabled channels. */
614 		if (slot_info->enabled_channels)
615 			continue;
616 
617 		/* Find the least used slot. */
618 		if (*slot == AD4130_INVALID_SLOT ||
619 		    slot_info->channels < st->slots_info[*slot].channels)
620 			*slot = i;
621 	}
622 
623 	if (*slot == AD4130_INVALID_SLOT)
624 		return -EINVAL;
625 
626 	*overwrite = true;
627 
628 	return 0;
629 }
630 
631 static void ad4130_unlink_channel(struct ad4130_state *st, unsigned int channel)
632 {
633 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
634 	struct ad4130_slot_info *slot_info = &st->slots_info[chan_info->slot];
635 
636 	chan_info->slot = AD4130_INVALID_SLOT;
637 	slot_info->channels--;
638 }
639 
640 static int ad4130_unlink_slot(struct ad4130_state *st, unsigned int slot)
641 {
642 	unsigned int i;
643 
644 	for (i = 0; i < AD4130_MAX_CHANNELS; i++) {
645 		struct ad4130_chan_info *chan_info = &st->chans_info[i];
646 
647 		if (!chan_info->initialized || chan_info->slot != slot)
648 			continue;
649 
650 		ad4130_unlink_channel(st, i);
651 	}
652 
653 	return 0;
654 }
655 
656 static int ad4130_link_channel_slot(struct ad4130_state *st,
657 				    unsigned int channel, unsigned int slot)
658 {
659 	struct ad4130_slot_info *slot_info = &st->slots_info[slot];
660 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
661 	int ret;
662 
663 	ret = regmap_update_bits(st->regmap, AD4130_CHANNEL_X_REG(channel),
664 				 AD4130_CHANNEL_SETUP_MASK,
665 				 FIELD_PREP(AD4130_CHANNEL_SETUP_MASK, slot));
666 	if (ret)
667 		return ret;
668 
669 	chan_info->slot = slot;
670 	slot_info->channels++;
671 
672 	return 0;
673 }
674 
675 static int ad4130_write_slot_setup(struct ad4130_state *st,
676 				   unsigned int slot,
677 				   struct ad4130_setup_info *setup_info)
678 {
679 	unsigned int val;
680 	int ret;
681 
682 	val = FIELD_PREP(AD4130_CONFIG_IOUT1_VAL_MASK, setup_info->iout0_val) |
683 	      FIELD_PREP(AD4130_CONFIG_IOUT1_VAL_MASK, setup_info->iout1_val) |
684 	      FIELD_PREP(AD4130_CONFIG_BURNOUT_MASK, setup_info->burnout) |
685 	      FIELD_PREP(AD4130_CONFIG_REF_BUFP_MASK, setup_info->ref_bufp) |
686 	      FIELD_PREP(AD4130_CONFIG_REF_BUFM_MASK, setup_info->ref_bufm) |
687 	      FIELD_PREP(AD4130_CONFIG_REF_SEL_MASK, setup_info->ref_sel) |
688 	      FIELD_PREP(AD4130_CONFIG_PGA_MASK, setup_info->pga);
689 
690 	ret = regmap_write(st->regmap, AD4130_CONFIG_X_REG(slot), val);
691 	if (ret)
692 		return ret;
693 
694 	val = FIELD_PREP(AD4130_FILTER_MODE_MASK, setup_info->filter_mode) |
695 	      FIELD_PREP(AD4130_FILTER_SELECT_MASK, setup_info->fs);
696 
697 	ret = regmap_write(st->regmap, AD4130_FILTER_X_REG(slot), val);
698 	if (ret)
699 		return ret;
700 
701 	memcpy(&st->slots_info[slot].setup, setup_info, sizeof(*setup_info));
702 
703 	return 0;
704 }
705 
706 static int ad4130_write_channel_setup(struct ad4130_state *st,
707 				      unsigned int channel, bool on_enable)
708 {
709 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
710 	struct ad4130_setup_info *setup_info = &chan_info->setup;
711 	bool overwrite;
712 	int slot;
713 	int ret;
714 
715 	/*
716 	 * The following cases need to be handled.
717 	 *
718 	 * 1. Enabled and linked channel with setup changes:
719 	 *    - Find a slot. If not possible, return error.
720 	 *    - Unlink channel from current slot.
721 	 *    - If the slot has channels linked to it, unlink all channels, and
722 	 *      write the new setup to it.
723 	 *    - Link channel to new slot.
724 	 *
725 	 * 2. Soon to be enabled and unlinked channel:
726 	 *    - Find a slot. If not possible, return error.
727 	 *    - If the slot has channels linked to it, unlink all channels, and
728 	 *      write the new setup to it.
729 	 *    - Link channel to the slot.
730 	 *
731 	 * 3. Disabled and linked channel with setup changes:
732 	 *    - Unlink channel from current slot.
733 	 *
734 	 * 4. Soon to be enabled and linked channel:
735 	 * 5. Disabled and unlinked channel with setup changes:
736 	 *    - Do nothing.
737 	 */
738 
739 	/* Case 4 */
740 	if (on_enable && chan_info->slot != AD4130_INVALID_SLOT)
741 		return 0;
742 
743 	if (!on_enable && !chan_info->enabled) {
744 		if (chan_info->slot != AD4130_INVALID_SLOT)
745 			/* Case 3 */
746 			ad4130_unlink_channel(st, channel);
747 
748 		/* Cases 3 & 5 */
749 		return 0;
750 	}
751 
752 	/* Cases 1 & 2 */
753 	ret = ad4130_find_slot(st, setup_info, &slot, &overwrite);
754 	if (ret)
755 		return ret;
756 
757 	if (chan_info->slot != AD4130_INVALID_SLOT)
758 		/* Case 1 */
759 		ad4130_unlink_channel(st, channel);
760 
761 	if (overwrite) {
762 		ret = ad4130_unlink_slot(st, slot);
763 		if (ret)
764 			return ret;
765 
766 		ret = ad4130_write_slot_setup(st, slot, setup_info);
767 		if (ret)
768 			return ret;
769 	}
770 
771 	return ad4130_link_channel_slot(st, channel, slot);
772 }
773 
774 static int ad4130_set_channel_enable(struct ad4130_state *st,
775 				     unsigned int channel, bool status)
776 {
777 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
778 	struct ad4130_slot_info *slot_info;
779 	int ret;
780 
781 	if (chan_info->enabled == status)
782 		return 0;
783 
784 	if (status) {
785 		ret = ad4130_write_channel_setup(st, channel, true);
786 		if (ret)
787 			return ret;
788 	}
789 
790 	slot_info = &st->slots_info[chan_info->slot];
791 
792 	ret = regmap_update_bits(st->regmap, AD4130_CHANNEL_X_REG(channel),
793 				 AD4130_CHANNEL_EN_MASK,
794 				 FIELD_PREP(AD4130_CHANNEL_EN_MASK, status));
795 	if (ret)
796 		return ret;
797 
798 	slot_info->enabled_channels += status ? 1 : -1;
799 	chan_info->enabled = status;
800 
801 	return 0;
802 }
803 
804 /*
805  * Table 58. FILTER_MODE_n bits and Filter Types of the datasheet describes
806  * the relation between filter mode, ODR and FS.
807  *
808  * Notice that the max ODR of each filter mode is not necessarily the
809  * absolute max ODR supported by the chip.
810  *
811  * The ODR divider is not explicitly specified, but it can be deduced based
812  * on the ODR range of each filter mode.
813  *
814  * For example, for Sinc4+Sinc1, max ODR is 218.18. That means that the
815  * absolute max ODR is divided by 11 to achieve the max ODR of this filter
816  * mode.
817  *
818  * The formulas for converting between ODR and FS for a specific filter
819  * mode can be deduced from the same table.
820  *
821  * Notice that FS = 1 actually means max ODR, and that ODR decreases by
822  * (maximum ODR / maximum FS) for each increment of FS.
823  *
824  * odr = MAX_ODR / odr_div * (1 - (fs - 1) / fs_max) <=>
825  * odr = MAX_ODR * (1 - (fs - 1) / fs_max) / odr_div <=>
826  * odr = MAX_ODR * (1 - (fs - 1) / fs_max) / odr_div <=>
827  * odr = MAX_ODR * (fs_max - fs + 1) / (fs_max * odr_div)
828  * (used in ad4130_fs_to_freq)
829  *
830  * For the opposite formula, FS can be extracted from the last one.
831  *
832  * MAX_ODR * (fs_max - fs + 1) = fs_max * odr_div * odr <=>
833  * fs_max - fs + 1 = fs_max * odr_div * odr / MAX_ODR <=>
834  * fs = 1 + fs_max - fs_max * odr_div * odr / MAX_ODR
835  * (used in ad4130_fs_to_freq)
836  */
837 
838 static void ad4130_freq_to_fs(enum ad4130_filter_mode filter_mode,
839 			      int val, int val2, unsigned int *fs)
840 {
841 	const struct ad4130_filter_config *filter_config =
842 		&ad4130_filter_configs[filter_mode];
843 	u64 dividend, divisor;
844 	int temp;
845 
846 	dividend = filter_config->fs_max * filter_config->odr_div *
847 		   ((u64)val * NANO + val2);
848 	divisor = (u64)AD4130_MAX_ODR * NANO;
849 
850 	temp = AD4130_FILTER_SELECT_MIN + filter_config->fs_max -
851 	       DIV64_U64_ROUND_CLOSEST(dividend, divisor);
852 
853 	if (temp < AD4130_FILTER_SELECT_MIN)
854 		temp = AD4130_FILTER_SELECT_MIN;
855 	else if (temp > filter_config->fs_max)
856 		temp = filter_config->fs_max;
857 
858 	*fs = temp;
859 }
860 
861 static void ad4130_fs_to_freq(enum ad4130_filter_mode filter_mode,
862 			      unsigned int fs, int *val, int *val2)
863 {
864 	const struct ad4130_filter_config *filter_config =
865 		&ad4130_filter_configs[filter_mode];
866 	unsigned int dividend, divisor;
867 	u64 temp;
868 
869 	dividend = (filter_config->fs_max - fs + AD4130_FILTER_SELECT_MIN) *
870 		   AD4130_MAX_ODR;
871 	divisor = filter_config->fs_max * filter_config->odr_div;
872 
873 	temp = div_u64((u64)dividend * NANO, divisor);
874 	*val = div_u64_rem(temp, NANO, val2);
875 }
876 
877 static int ad4130_set_filter_mode(struct iio_dev *indio_dev,
878 				  const struct iio_chan_spec *chan,
879 				  unsigned int val)
880 {
881 	struct ad4130_state *st = iio_priv(indio_dev);
882 	unsigned int channel = chan->scan_index;
883 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
884 	struct ad4130_setup_info *setup_info = &chan_info->setup;
885 	enum ad4130_filter_mode old_filter_mode;
886 	int freq_val, freq_val2;
887 	unsigned int old_fs;
888 	int ret = 0;
889 
890 	mutex_lock(&st->lock);
891 	if (setup_info->filter_mode == val)
892 		goto out;
893 
894 	old_fs = setup_info->fs;
895 	old_filter_mode = setup_info->filter_mode;
896 
897 	/*
898 	 * When switching between filter modes, try to match the ODR as
899 	 * close as possible. To do this, convert the current FS into ODR
900 	 * using the old filter mode, then convert it back into FS using
901 	 * the new filter mode.
902 	 */
903 	ad4130_fs_to_freq(setup_info->filter_mode, setup_info->fs,
904 			  &freq_val, &freq_val2);
905 
906 	ad4130_freq_to_fs(val, freq_val, freq_val2, &setup_info->fs);
907 
908 	setup_info->filter_mode = val;
909 
910 	ret = ad4130_write_channel_setup(st, channel, false);
911 	if (ret) {
912 		setup_info->fs = old_fs;
913 		setup_info->filter_mode = old_filter_mode;
914 	}
915 
916  out:
917 	mutex_unlock(&st->lock);
918 
919 	return ret;
920 }
921 
922 static int ad4130_get_filter_mode(struct iio_dev *indio_dev,
923 				  const struct iio_chan_spec *chan)
924 {
925 	struct ad4130_state *st = iio_priv(indio_dev);
926 	unsigned int channel = chan->scan_index;
927 	struct ad4130_setup_info *setup_info = &st->chans_info[channel].setup;
928 	enum ad4130_filter_mode filter_mode;
929 
930 	mutex_lock(&st->lock);
931 	filter_mode = setup_info->filter_mode;
932 	mutex_unlock(&st->lock);
933 
934 	return filter_mode;
935 }
936 
937 static const struct iio_enum ad4130_filter_mode_enum = {
938 	.items = ad4130_filter_modes_str,
939 	.num_items = ARRAY_SIZE(ad4130_filter_modes_str),
940 	.set = ad4130_set_filter_mode,
941 	.get = ad4130_get_filter_mode,
942 };
943 
944 static const struct iio_chan_spec_ext_info ad4130_filter_mode_ext_info[] = {
945 	IIO_ENUM("filter_mode", IIO_SEPARATE, &ad4130_filter_mode_enum),
946 	IIO_ENUM_AVAILABLE("filter_mode", IIO_SHARED_BY_TYPE,
947 			   &ad4130_filter_mode_enum),
948 	{ }
949 };
950 
951 static const struct iio_chan_spec ad4130_channel_template = {
952 	.type = IIO_VOLTAGE,
953 	.indexed = 1,
954 	.differential = 1,
955 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
956 			      BIT(IIO_CHAN_INFO_SCALE) |
957 			      BIT(IIO_CHAN_INFO_OFFSET) |
958 			      BIT(IIO_CHAN_INFO_SAMP_FREQ),
959 	.info_mask_separate_available = BIT(IIO_CHAN_INFO_SCALE) |
960 					BIT(IIO_CHAN_INFO_SAMP_FREQ),
961 	.ext_info = ad4130_filter_mode_ext_info,
962 	.scan_type = {
963 		.sign = 'u',
964 		.endianness = IIO_BE,
965 	},
966 };
967 
968 static int ad4130_set_channel_pga(struct ad4130_state *st, unsigned int channel,
969 				  int val, int val2)
970 {
971 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
972 	struct ad4130_setup_info *setup_info = &chan_info->setup;
973 	unsigned int pga, old_pga;
974 	int ret = 0;
975 
976 	for (pga = 0; pga < AD4130_MAX_PGA; pga++)
977 		if (val == st->scale_tbls[setup_info->ref_sel][pga][0] &&
978 		    val2 == st->scale_tbls[setup_info->ref_sel][pga][1])
979 			break;
980 
981 	if (pga == AD4130_MAX_PGA)
982 		return -EINVAL;
983 
984 	mutex_lock(&st->lock);
985 	if (pga == setup_info->pga)
986 		goto out;
987 
988 	old_pga = setup_info->pga;
989 	setup_info->pga = pga;
990 
991 	ret = ad4130_write_channel_setup(st, channel, false);
992 	if (ret)
993 		setup_info->pga = old_pga;
994 
995 out:
996 	mutex_unlock(&st->lock);
997 
998 	return ret;
999 }
1000 
1001 static int ad4130_set_channel_freq(struct ad4130_state *st,
1002 				   unsigned int channel, int val, int val2)
1003 {
1004 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
1005 	struct ad4130_setup_info *setup_info = &chan_info->setup;
1006 	unsigned int fs, old_fs;
1007 	int ret = 0;
1008 
1009 	mutex_lock(&st->lock);
1010 	old_fs = setup_info->fs;
1011 
1012 	ad4130_freq_to_fs(setup_info->filter_mode, val, val2, &fs);
1013 
1014 	if (fs == setup_info->fs)
1015 		goto out;
1016 
1017 	setup_info->fs = fs;
1018 
1019 	ret = ad4130_write_channel_setup(st, channel, false);
1020 	if (ret)
1021 		setup_info->fs = old_fs;
1022 
1023 out:
1024 	mutex_unlock(&st->lock);
1025 
1026 	return ret;
1027 }
1028 
1029 static int _ad4130_read_sample(struct iio_dev *indio_dev, unsigned int channel,
1030 			       int *val)
1031 {
1032 	struct ad4130_state *st = iio_priv(indio_dev);
1033 	int ret;
1034 
1035 	ret = ad4130_set_channel_enable(st, channel, true);
1036 	if (ret)
1037 		return ret;
1038 
1039 	reinit_completion(&st->completion);
1040 
1041 	ret = ad4130_set_mode(st, AD4130_MODE_CONTINUOUS);
1042 	if (ret)
1043 		return ret;
1044 
1045 	ret = wait_for_completion_timeout(&st->completion,
1046 					  msecs_to_jiffies(1000));
1047 	if (!ret)
1048 		return -ETIMEDOUT;
1049 
1050 	ret = ad4130_set_mode(st, AD4130_MODE_IDLE);
1051 	if (ret)
1052 		return ret;
1053 
1054 	ret = regmap_read(st->regmap, AD4130_DATA_REG, val);
1055 	if (ret)
1056 		return ret;
1057 
1058 	ret = ad4130_set_channel_enable(st, channel, false);
1059 	if (ret)
1060 		return ret;
1061 
1062 	return IIO_VAL_INT;
1063 }
1064 
1065 static int ad4130_read_sample(struct iio_dev *indio_dev, unsigned int channel,
1066 			      int *val)
1067 {
1068 	struct ad4130_state *st = iio_priv(indio_dev);
1069 	int ret;
1070 
1071 	ret = iio_device_claim_direct_mode(indio_dev);
1072 	if (ret)
1073 		return ret;
1074 
1075 	mutex_lock(&st->lock);
1076 	ret = _ad4130_read_sample(indio_dev, channel, val);
1077 	mutex_unlock(&st->lock);
1078 
1079 	iio_device_release_direct_mode(indio_dev);
1080 
1081 	return ret;
1082 }
1083 
1084 static int ad4130_read_raw(struct iio_dev *indio_dev,
1085 			   struct iio_chan_spec const *chan,
1086 			   int *val, int *val2, long info)
1087 {
1088 	struct ad4130_state *st = iio_priv(indio_dev);
1089 	unsigned int channel = chan->scan_index;
1090 	struct ad4130_setup_info *setup_info = &st->chans_info[channel].setup;
1091 
1092 	switch (info) {
1093 	case IIO_CHAN_INFO_RAW:
1094 		return ad4130_read_sample(indio_dev, channel, val);
1095 	case IIO_CHAN_INFO_SCALE:
1096 		mutex_lock(&st->lock);
1097 		*val = st->scale_tbls[setup_info->ref_sel][setup_info->pga][0];
1098 		*val2 = st->scale_tbls[setup_info->ref_sel][setup_info->pga][1];
1099 		mutex_unlock(&st->lock);
1100 
1101 		return IIO_VAL_INT_PLUS_NANO;
1102 	case IIO_CHAN_INFO_OFFSET:
1103 		*val = st->bipolar ? -BIT(chan->scan_type.realbits - 1) : 0;
1104 
1105 		return IIO_VAL_INT;
1106 	case IIO_CHAN_INFO_SAMP_FREQ:
1107 		mutex_lock(&st->lock);
1108 		ad4130_fs_to_freq(setup_info->filter_mode, setup_info->fs,
1109 				  val, val2);
1110 		mutex_unlock(&st->lock);
1111 
1112 		return IIO_VAL_INT_PLUS_NANO;
1113 	default:
1114 		return -EINVAL;
1115 	}
1116 }
1117 
1118 static int ad4130_read_avail(struct iio_dev *indio_dev,
1119 			     struct iio_chan_spec const *chan,
1120 			     const int **vals, int *type, int *length,
1121 			     long info)
1122 {
1123 	struct ad4130_state *st = iio_priv(indio_dev);
1124 	unsigned int channel = chan->scan_index;
1125 	struct ad4130_setup_info *setup_info = &st->chans_info[channel].setup;
1126 	const struct ad4130_filter_config *filter_config;
1127 
1128 	switch (info) {
1129 	case IIO_CHAN_INFO_SCALE:
1130 		*vals = (int *)st->scale_tbls[setup_info->ref_sel];
1131 		*length = ARRAY_SIZE(st->scale_tbls[setup_info->ref_sel]) * 2;
1132 
1133 		*type = IIO_VAL_INT_PLUS_NANO;
1134 
1135 		return IIO_AVAIL_LIST;
1136 	case IIO_CHAN_INFO_SAMP_FREQ:
1137 		mutex_lock(&st->lock);
1138 		filter_config = &ad4130_filter_configs[setup_info->filter_mode];
1139 		mutex_unlock(&st->lock);
1140 
1141 		*vals = (int *)filter_config->samp_freq_avail;
1142 		*length = filter_config->samp_freq_avail_len * 2;
1143 		*type = IIO_VAL_FRACTIONAL;
1144 
1145 		return filter_config->samp_freq_avail_type;
1146 	default:
1147 		return -EINVAL;
1148 	}
1149 }
1150 
1151 static int ad4130_write_raw_get_fmt(struct iio_dev *indio_dev,
1152 				    struct iio_chan_spec const *chan,
1153 				    long info)
1154 {
1155 	switch (info) {
1156 	case IIO_CHAN_INFO_SCALE:
1157 	case IIO_CHAN_INFO_SAMP_FREQ:
1158 		return IIO_VAL_INT_PLUS_NANO;
1159 	default:
1160 		return -EINVAL;
1161 	}
1162 }
1163 
1164 static int ad4130_write_raw(struct iio_dev *indio_dev,
1165 			    struct iio_chan_spec const *chan,
1166 			    int val, int val2, long info)
1167 {
1168 	struct ad4130_state *st = iio_priv(indio_dev);
1169 	unsigned int channel = chan->scan_index;
1170 
1171 	switch (info) {
1172 	case IIO_CHAN_INFO_SCALE:
1173 		return ad4130_set_channel_pga(st, channel, val, val2);
1174 	case IIO_CHAN_INFO_SAMP_FREQ:
1175 		return ad4130_set_channel_freq(st, channel, val, val2);
1176 	default:
1177 		return -EINVAL;
1178 	}
1179 }
1180 
1181 static int ad4130_reg_access(struct iio_dev *indio_dev, unsigned int reg,
1182 			     unsigned int writeval, unsigned int *readval)
1183 {
1184 	struct ad4130_state *st = iio_priv(indio_dev);
1185 
1186 	if (readval)
1187 		return regmap_read(st->regmap, reg, readval);
1188 
1189 	return regmap_write(st->regmap, reg, writeval);
1190 }
1191 
1192 static int ad4130_update_scan_mode(struct iio_dev *indio_dev,
1193 				   const unsigned long *scan_mask)
1194 {
1195 	struct ad4130_state *st = iio_priv(indio_dev);
1196 	unsigned int channel;
1197 	unsigned int val = 0;
1198 	int ret;
1199 
1200 	mutex_lock(&st->lock);
1201 
1202 	for_each_set_bit(channel, scan_mask, indio_dev->num_channels) {
1203 		ret = ad4130_set_channel_enable(st, channel, true);
1204 		if (ret)
1205 			goto out;
1206 
1207 		val++;
1208 	}
1209 
1210 	st->num_enabled_channels = val;
1211 
1212 out:
1213 	mutex_unlock(&st->lock);
1214 
1215 	return 0;
1216 }
1217 
1218 static int ad4130_set_fifo_watermark(struct iio_dev *indio_dev, unsigned int val)
1219 {
1220 	struct ad4130_state *st = iio_priv(indio_dev);
1221 	unsigned int eff;
1222 	int ret;
1223 
1224 	if (val > AD4130_FIFO_SIZE)
1225 		return -EINVAL;
1226 
1227 	eff = val * st->num_enabled_channels;
1228 	if (eff > AD4130_FIFO_SIZE)
1229 		/*
1230 		 * Always set watermark to a multiple of the number of
1231 		 * enabled channels to avoid making the FIFO unaligned.
1232 		 */
1233 		eff = rounddown(AD4130_FIFO_SIZE, st->num_enabled_channels);
1234 
1235 	mutex_lock(&st->lock);
1236 
1237 	ret = regmap_update_bits(st->regmap, AD4130_FIFO_CONTROL_REG,
1238 				 AD4130_FIFO_CONTROL_WM_MASK,
1239 				 FIELD_PREP(AD4130_FIFO_CONTROL_WM_MASK,
1240 					    ad4130_watermark_reg_val(eff)));
1241 	if (ret)
1242 		goto out;
1243 
1244 	st->effective_watermark = eff;
1245 	st->watermark = val;
1246 
1247 out:
1248 	mutex_unlock(&st->lock);
1249 
1250 	return ret;
1251 }
1252 
1253 static const struct iio_info ad4130_info = {
1254 	.read_raw = ad4130_read_raw,
1255 	.read_avail = ad4130_read_avail,
1256 	.write_raw_get_fmt = ad4130_write_raw_get_fmt,
1257 	.write_raw = ad4130_write_raw,
1258 	.update_scan_mode = ad4130_update_scan_mode,
1259 	.hwfifo_set_watermark = ad4130_set_fifo_watermark,
1260 	.debugfs_reg_access = ad4130_reg_access,
1261 };
1262 
1263 static int ad4130_buffer_postenable(struct iio_dev *indio_dev)
1264 {
1265 	struct ad4130_state *st = iio_priv(indio_dev);
1266 	int ret;
1267 
1268 	mutex_lock(&st->lock);
1269 
1270 	ret = ad4130_set_watermark_interrupt_en(st, true);
1271 	if (ret)
1272 		goto out;
1273 
1274 	ret = irq_set_irq_type(st->spi->irq, st->inv_irq_trigger);
1275 	if (ret)
1276 		goto out;
1277 
1278 	ret = ad4130_set_fifo_mode(st, AD4130_FIFO_MODE_WM);
1279 	if (ret)
1280 		goto out;
1281 
1282 	ret = ad4130_set_mode(st, AD4130_MODE_CONTINUOUS);
1283 
1284 out:
1285 	mutex_unlock(&st->lock);
1286 
1287 	return ret;
1288 }
1289 
1290 static int ad4130_buffer_predisable(struct iio_dev *indio_dev)
1291 {
1292 	struct ad4130_state *st = iio_priv(indio_dev);
1293 	unsigned int i;
1294 	int ret;
1295 
1296 	mutex_lock(&st->lock);
1297 
1298 	ret = ad4130_set_mode(st, AD4130_MODE_IDLE);
1299 	if (ret)
1300 		goto out;
1301 
1302 	ret = irq_set_irq_type(st->spi->irq, st->irq_trigger);
1303 	if (ret)
1304 		goto out;
1305 
1306 	ret = ad4130_set_fifo_mode(st, AD4130_FIFO_MODE_DISABLED);
1307 	if (ret)
1308 		goto out;
1309 
1310 	ret = ad4130_set_watermark_interrupt_en(st, false);
1311 	if (ret)
1312 		goto out;
1313 
1314 	/*
1315 	 * update_scan_mode() is not called in the disable path, disable all
1316 	 * channels here.
1317 	 */
1318 	for (i = 0; i < indio_dev->num_channels; i++) {
1319 		ret = ad4130_set_channel_enable(st, i, false);
1320 		if (ret)
1321 			goto out;
1322 	}
1323 
1324 out:
1325 	mutex_unlock(&st->lock);
1326 
1327 	return ret;
1328 }
1329 
1330 static const struct iio_buffer_setup_ops ad4130_buffer_ops = {
1331 	.postenable = ad4130_buffer_postenable,
1332 	.predisable = ad4130_buffer_predisable,
1333 };
1334 
1335 static ssize_t hwfifo_watermark_show(struct device *dev,
1336 				     struct device_attribute *attr, char *buf)
1337 {
1338 	struct ad4130_state *st = iio_priv(dev_to_iio_dev(dev));
1339 	unsigned int val;
1340 
1341 	mutex_lock(&st->lock);
1342 	val = st->watermark;
1343 	mutex_unlock(&st->lock);
1344 
1345 	return sysfs_emit(buf, "%d\n", val);
1346 }
1347 
1348 static ssize_t hwfifo_enabled_show(struct device *dev,
1349 				   struct device_attribute *attr, char *buf)
1350 {
1351 	struct ad4130_state *st = iio_priv(dev_to_iio_dev(dev));
1352 	unsigned int val;
1353 	int ret;
1354 
1355 	ret = regmap_read(st->regmap, AD4130_FIFO_CONTROL_REG, &val);
1356 	if (ret)
1357 		return ret;
1358 
1359 	val = FIELD_GET(AD4130_FIFO_CONTROL_MODE_MASK, val);
1360 
1361 	return sysfs_emit(buf, "%d\n", val != AD4130_FIFO_MODE_DISABLED);
1362 }
1363 
1364 static ssize_t hwfifo_watermark_min_show(struct device *dev,
1365 					 struct device_attribute *attr,
1366 					 char *buf)
1367 {
1368 	return sysfs_emit(buf, "%s\n", "1");
1369 }
1370 
1371 static ssize_t hwfifo_watermark_max_show(struct device *dev,
1372 					 struct device_attribute *attr,
1373 					 char *buf)
1374 {
1375 	return sysfs_emit(buf, "%s\n", __stringify(AD4130_FIFO_SIZE));
1376 }
1377 
1378 static IIO_DEVICE_ATTR_RO(hwfifo_watermark_min, 0);
1379 static IIO_DEVICE_ATTR_RO(hwfifo_watermark_max, 0);
1380 static IIO_DEVICE_ATTR_RO(hwfifo_watermark, 0);
1381 static IIO_DEVICE_ATTR_RO(hwfifo_enabled, 0);
1382 
1383 static const struct iio_dev_attr *ad4130_fifo_attributes[] = {
1384 	&iio_dev_attr_hwfifo_watermark_min,
1385 	&iio_dev_attr_hwfifo_watermark_max,
1386 	&iio_dev_attr_hwfifo_watermark,
1387 	&iio_dev_attr_hwfifo_enabled,
1388 	NULL
1389 };
1390 
1391 static int _ad4130_find_table_index(const unsigned int *tbl, size_t len,
1392 				    unsigned int val)
1393 {
1394 	unsigned int i;
1395 
1396 	for (i = 0; i < len; i++)
1397 		if (tbl[i] == val)
1398 			return i;
1399 
1400 	return -EINVAL;
1401 }
1402 
1403 #define ad4130_find_table_index(table, val) \
1404 	_ad4130_find_table_index(table, ARRAY_SIZE(table), val)
1405 
1406 static int ad4130_get_ref_voltage(struct ad4130_state *st,
1407 				  enum ad4130_ref_sel ref_sel)
1408 {
1409 	switch (ref_sel) {
1410 	case AD4130_REF_REFIN1:
1411 		return regulator_get_voltage(st->regulators[2].consumer);
1412 	case AD4130_REF_REFIN2:
1413 		return regulator_get_voltage(st->regulators[3].consumer);
1414 	case AD4130_REF_AVDD_AVSS:
1415 		return regulator_get_voltage(st->regulators[0].consumer);
1416 	case AD4130_REF_REFOUT_AVSS:
1417 		return st->int_ref_uv;
1418 	default:
1419 		return -EINVAL;
1420 	}
1421 }
1422 
1423 static int ad4130_parse_fw_setup(struct ad4130_state *st,
1424 				 struct fwnode_handle *child,
1425 				 struct ad4130_setup_info *setup_info)
1426 {
1427 	struct device *dev = &st->spi->dev;
1428 	u32 tmp;
1429 	int ret;
1430 
1431 	tmp = 0;
1432 	fwnode_property_read_u32(child, "adi,excitation-current-0-nanoamp", &tmp);
1433 	ret = ad4130_find_table_index(ad4130_iout_current_na_tbl, tmp);
1434 	if (ret < 0)
1435 		return dev_err_probe(dev, ret,
1436 				     "Invalid excitation current %unA\n", tmp);
1437 	setup_info->iout0_val = ret;
1438 
1439 	tmp = 0;
1440 	fwnode_property_read_u32(child, "adi,excitation-current-1-nanoamp", &tmp);
1441 	ret = ad4130_find_table_index(ad4130_iout_current_na_tbl, tmp);
1442 	if (ret < 0)
1443 		return dev_err_probe(dev, ret,
1444 				     "Invalid excitation current %unA\n", tmp);
1445 	setup_info->iout1_val = ret;
1446 
1447 	tmp = 0;
1448 	fwnode_property_read_u32(child, "adi,burnout-current-nanoamp", &tmp);
1449 	ret = ad4130_find_table_index(ad4130_burnout_current_na_tbl, tmp);
1450 	if (ret < 0)
1451 		return dev_err_probe(dev, ret,
1452 				     "Invalid burnout current %unA\n", tmp);
1453 	setup_info->burnout = ret;
1454 
1455 	setup_info->ref_bufp = fwnode_property_read_bool(child, "adi,buffered-positive");
1456 	setup_info->ref_bufm = fwnode_property_read_bool(child, "adi,buffered-negative");
1457 
1458 	setup_info->ref_sel = AD4130_REF_REFIN1;
1459 	fwnode_property_read_u32(child, "adi,reference-select",
1460 				 &setup_info->ref_sel);
1461 	if (setup_info->ref_sel >= AD4130_REF_SEL_MAX)
1462 		return dev_err_probe(dev, -EINVAL,
1463 				     "Invalid reference selected %u\n",
1464 				     setup_info->ref_sel);
1465 
1466 	if (setup_info->ref_sel == AD4130_REF_REFOUT_AVSS)
1467 		st->int_ref_en = true;
1468 
1469 	ret = ad4130_get_ref_voltage(st, setup_info->ref_sel);
1470 	if (ret < 0)
1471 		return dev_err_probe(dev, ret, "Cannot use reference %u\n",
1472 				     setup_info->ref_sel);
1473 
1474 	return 0;
1475 }
1476 
1477 static int ad4130_validate_diff_channel(struct ad4130_state *st, u32 pin)
1478 {
1479 	struct device *dev = &st->spi->dev;
1480 
1481 	if (pin >= AD4130_MAX_DIFF_INPUTS)
1482 		return dev_err_probe(dev, -EINVAL,
1483 				     "Invalid differential channel %u\n", pin);
1484 
1485 	if (pin >= AD4130_MAX_ANALOG_PINS)
1486 		return 0;
1487 
1488 	if (st->pins_fn[pin] == AD4130_PIN_FN_SPECIAL)
1489 		return dev_err_probe(dev, -EINVAL,
1490 				     "Pin %u already used with fn %u\n", pin,
1491 				     st->pins_fn[pin]);
1492 
1493 	st->pins_fn[pin] |= AD4130_PIN_FN_DIFF;
1494 
1495 	return 0;
1496 }
1497 
1498 static int ad4130_validate_diff_channels(struct ad4130_state *st,
1499 					 u32 *pins, unsigned int len)
1500 {
1501 	unsigned int i;
1502 	int ret;
1503 
1504 	for (i = 0; i < len; i++) {
1505 		ret = ad4130_validate_diff_channel(st, pins[i]);
1506 		if (ret)
1507 			return ret;
1508 	}
1509 
1510 	return 0;
1511 }
1512 
1513 static int ad4130_validate_excitation_pin(struct ad4130_state *st, u32 pin)
1514 {
1515 	struct device *dev = &st->spi->dev;
1516 
1517 	if (pin >= AD4130_MAX_ANALOG_PINS)
1518 		return dev_err_probe(dev, -EINVAL,
1519 				     "Invalid excitation pin %u\n", pin);
1520 
1521 	if (st->pins_fn[pin] == AD4130_PIN_FN_SPECIAL)
1522 		return dev_err_probe(dev, -EINVAL,
1523 				     "Pin %u already used with fn %u\n", pin,
1524 				     st->pins_fn[pin]);
1525 
1526 	st->pins_fn[pin] |= AD4130_PIN_FN_EXCITATION;
1527 
1528 	return 0;
1529 }
1530 
1531 static int ad4130_validate_vbias_pin(struct ad4130_state *st, u32 pin)
1532 {
1533 	struct device *dev = &st->spi->dev;
1534 
1535 	if (pin >= AD4130_MAX_ANALOG_PINS)
1536 		return dev_err_probe(dev, -EINVAL, "Invalid vbias pin %u\n",
1537 				     pin);
1538 
1539 	if (st->pins_fn[pin] == AD4130_PIN_FN_SPECIAL)
1540 		return dev_err_probe(dev, -EINVAL,
1541 				     "Pin %u already used with fn %u\n", pin,
1542 				     st->pins_fn[pin]);
1543 
1544 	st->pins_fn[pin] |= AD4130_PIN_FN_VBIAS;
1545 
1546 	return 0;
1547 }
1548 
1549 static int ad4130_validate_vbias_pins(struct ad4130_state *st,
1550 				      u32 *pins, unsigned int len)
1551 {
1552 	unsigned int i;
1553 	int ret;
1554 
1555 	for (i = 0; i < st->num_vbias_pins; i++) {
1556 		ret = ad4130_validate_vbias_pin(st, pins[i]);
1557 		if (ret)
1558 			return ret;
1559 	}
1560 
1561 	return 0;
1562 }
1563 
1564 static int ad4130_parse_fw_channel(struct iio_dev *indio_dev,
1565 				   struct fwnode_handle *child)
1566 {
1567 	struct ad4130_state *st = iio_priv(indio_dev);
1568 	unsigned int resolution = ad4130_resolution(st);
1569 	unsigned int index = indio_dev->num_channels++;
1570 	struct device *dev = &st->spi->dev;
1571 	struct ad4130_chan_info *chan_info;
1572 	struct iio_chan_spec *chan;
1573 	u32 pins[2];
1574 	int ret;
1575 
1576 	if (index >= AD4130_MAX_CHANNELS)
1577 		return dev_err_probe(dev, -EINVAL, "Too many channels\n");
1578 
1579 	chan = &st->chans[index];
1580 	chan_info = &st->chans_info[index];
1581 
1582 	*chan = ad4130_channel_template;
1583 	chan->scan_type.realbits = resolution;
1584 	chan->scan_type.storagebits = resolution;
1585 	chan->scan_index = index;
1586 
1587 	chan_info->slot = AD4130_INVALID_SLOT;
1588 	chan_info->setup.fs = AD4130_FILTER_SELECT_MIN;
1589 	chan_info->initialized = true;
1590 
1591 	ret = fwnode_property_read_u32_array(child, "diff-channels", pins,
1592 					     ARRAY_SIZE(pins));
1593 	if (ret)
1594 		return ret;
1595 
1596 	ret = ad4130_validate_diff_channels(st, pins, ARRAY_SIZE(pins));
1597 	if (ret)
1598 		return ret;
1599 
1600 	chan->channel = pins[0];
1601 	chan->channel2 = pins[1];
1602 
1603 	ret = ad4130_parse_fw_setup(st, child, &chan_info->setup);
1604 	if (ret)
1605 		return ret;
1606 
1607 	fwnode_property_read_u32(child, "adi,excitation-pin-0",
1608 				 &chan_info->iout0);
1609 	if (chan_info->setup.iout0_val != AD4130_IOUT_OFF) {
1610 		ret = ad4130_validate_excitation_pin(st, chan_info->iout0);
1611 		if (ret)
1612 			return ret;
1613 	}
1614 
1615 	fwnode_property_read_u32(child, "adi,excitation-pin-1",
1616 				 &chan_info->iout1);
1617 	if (chan_info->setup.iout1_val != AD4130_IOUT_OFF) {
1618 		ret = ad4130_validate_excitation_pin(st, chan_info->iout1);
1619 		if (ret)
1620 			return ret;
1621 	}
1622 
1623 	return 0;
1624 }
1625 
1626 static int ad4130_parse_fw_children(struct iio_dev *indio_dev)
1627 {
1628 	struct ad4130_state *st = iio_priv(indio_dev);
1629 	struct device *dev = &st->spi->dev;
1630 	struct fwnode_handle *child;
1631 	int ret;
1632 
1633 	indio_dev->channels = st->chans;
1634 
1635 	device_for_each_child_node(dev, child) {
1636 		ret = ad4130_parse_fw_channel(indio_dev, child);
1637 		if (ret) {
1638 			fwnode_handle_put(child);
1639 			return ret;
1640 		}
1641 	}
1642 
1643 	return 0;
1644 }
1645 
1646 static int ad4310_parse_fw(struct iio_dev *indio_dev)
1647 {
1648 	struct ad4130_state *st = iio_priv(indio_dev);
1649 	struct device *dev = &st->spi->dev;
1650 	u32 ext_clk_freq = AD4130_MCLK_FREQ_76_8KHZ;
1651 	unsigned int i;
1652 	int avdd_uv;
1653 	int irq;
1654 	int ret;
1655 
1656 	st->mclk = devm_clk_get_optional(dev, "mclk");
1657 	if (IS_ERR(st->mclk))
1658 		return dev_err_probe(dev, PTR_ERR(st->mclk),
1659 				     "Failed to get mclk\n");
1660 
1661 	st->int_pin_sel = AD4130_INT_PIN_INT;
1662 
1663 	for (i = 0; i < ARRAY_SIZE(ad4130_int_pin_names); i++) {
1664 		irq = fwnode_irq_get_byname(dev_fwnode(dev),
1665 					    ad4130_int_pin_names[i]);
1666 		if (irq > 0) {
1667 			st->int_pin_sel = i;
1668 			break;
1669 		}
1670 	}
1671 
1672 	if (st->int_pin_sel == AD4130_INT_PIN_DOUT)
1673 		return dev_err_probe(dev, -EINVAL,
1674 				     "Cannot use DOUT as interrupt pin\n");
1675 
1676 	if (st->int_pin_sel == AD4130_INT_PIN_P2)
1677 		st->pins_fn[AD4130_AIN3_P2] = AD4130_PIN_FN_SPECIAL;
1678 
1679 	device_property_read_u32(dev, "adi,ext-clk-freq-hz", &ext_clk_freq);
1680 	if (ext_clk_freq != AD4130_MCLK_FREQ_153_6KHZ &&
1681 	    ext_clk_freq != AD4130_MCLK_FREQ_76_8KHZ)
1682 		return dev_err_probe(dev, -EINVAL,
1683 				     "Invalid external clock frequency %u\n",
1684 				     ext_clk_freq);
1685 
1686 	if (st->mclk && ext_clk_freq == AD4130_MCLK_FREQ_153_6KHZ)
1687 		st->mclk_sel = AD4130_MCLK_153_6KHZ_EXT;
1688 	else if (st->mclk)
1689 		st->mclk_sel = AD4130_MCLK_76_8KHZ_EXT;
1690 	else
1691 		st->mclk_sel = AD4130_MCLK_76_8KHZ;
1692 
1693 	if (st->int_pin_sel == AD4130_INT_PIN_CLK &&
1694 	    st->mclk_sel != AD4130_MCLK_76_8KHZ)
1695 		return dev_err_probe(dev, -EINVAL,
1696 				     "Invalid clock %u for interrupt pin %u\n",
1697 				     st->mclk_sel, st->int_pin_sel);
1698 
1699 	st->int_ref_uv = AD4130_INT_REF_2_5V;
1700 
1701 	/*
1702 	 * When the AVDD supply is set to below 2.5V the internal reference of
1703 	 * 1.25V should be selected.
1704 	 * See datasheet page 37, section ADC REFERENCE.
1705 	 */
1706 	avdd_uv = regulator_get_voltage(st->regulators[0].consumer);
1707 	if (avdd_uv > 0 && avdd_uv < AD4130_INT_REF_2_5V)
1708 		st->int_ref_uv = AD4130_INT_REF_1_25V;
1709 
1710 	st->bipolar = device_property_read_bool(dev, "adi,bipolar");
1711 
1712 	ret = device_property_count_u32(dev, "adi,vbias-pins");
1713 	if (ret > 0) {
1714 		if (ret > AD4130_MAX_ANALOG_PINS)
1715 			return dev_err_probe(dev, -EINVAL,
1716 					     "Too many vbias pins %u\n", ret);
1717 
1718 		st->num_vbias_pins = ret;
1719 
1720 		ret = device_property_read_u32_array(dev, "adi,vbias-pins",
1721 						     st->vbias_pins,
1722 						     st->num_vbias_pins);
1723 		if (ret)
1724 			return dev_err_probe(dev, ret,
1725 					     "Failed to read vbias pins\n");
1726 
1727 		ret = ad4130_validate_vbias_pins(st, st->vbias_pins,
1728 						 st->num_vbias_pins);
1729 		if (ret)
1730 			return ret;
1731 	}
1732 
1733 	ret = ad4130_parse_fw_children(indio_dev);
1734 	if (ret)
1735 		return ret;
1736 
1737 	return 0;
1738 }
1739 
1740 static void ad4130_fill_scale_tbls(struct ad4130_state *st)
1741 {
1742 	unsigned int pow = ad4130_resolution(st) - st->bipolar;
1743 	unsigned int i, j;
1744 
1745 	for (i = 0; i < AD4130_REF_SEL_MAX; i++) {
1746 		int ret;
1747 		u64 nv;
1748 
1749 		ret = ad4130_get_ref_voltage(st, i);
1750 		if (ret < 0)
1751 			continue;
1752 
1753 		nv = (u64)ret * NANO;
1754 
1755 		for (j = 0; j < AD4130_MAX_PGA; j++)
1756 			st->scale_tbls[i][j][1] = div_u64(nv >> (pow + j), MILLI);
1757 	}
1758 }
1759 
1760 static void ad4130_clk_disable_unprepare(void *clk)
1761 {
1762 	clk_disable_unprepare(clk);
1763 }
1764 
1765 static int ad4130_set_mclk_sel(struct ad4130_state *st,
1766 			       enum ad4130_mclk_sel mclk_sel)
1767 {
1768 	return regmap_update_bits(st->regmap, AD4130_ADC_CONTROL_REG,
1769 				 AD4130_ADC_CONTROL_MCLK_SEL_MASK,
1770 				 FIELD_PREP(AD4130_ADC_CONTROL_MCLK_SEL_MASK,
1771 					    mclk_sel));
1772 }
1773 
1774 static unsigned long ad4130_int_clk_recalc_rate(struct clk_hw *hw,
1775 						unsigned long parent_rate)
1776 {
1777 	return AD4130_MCLK_FREQ_76_8KHZ;
1778 }
1779 
1780 static int ad4130_int_clk_is_enabled(struct clk_hw *hw)
1781 {
1782 	struct ad4130_state *st = container_of(hw, struct ad4130_state, int_clk_hw);
1783 
1784 	return st->mclk_sel == AD4130_MCLK_76_8KHZ_OUT;
1785 }
1786 
1787 static int ad4130_int_clk_prepare(struct clk_hw *hw)
1788 {
1789 	struct ad4130_state *st = container_of(hw, struct ad4130_state, int_clk_hw);
1790 	int ret;
1791 
1792 	ret = ad4130_set_mclk_sel(st, AD4130_MCLK_76_8KHZ_OUT);
1793 	if (ret)
1794 		return ret;
1795 
1796 	st->mclk_sel = AD4130_MCLK_76_8KHZ_OUT;
1797 
1798 	return 0;
1799 }
1800 
1801 static void ad4130_int_clk_unprepare(struct clk_hw *hw)
1802 {
1803 	struct ad4130_state *st = container_of(hw, struct ad4130_state, int_clk_hw);
1804 	int ret;
1805 
1806 	ret = ad4130_set_mclk_sel(st, AD4130_MCLK_76_8KHZ);
1807 	if (ret)
1808 		return;
1809 
1810 	st->mclk_sel = AD4130_MCLK_76_8KHZ;
1811 }
1812 
1813 static const struct clk_ops ad4130_int_clk_ops = {
1814 	.recalc_rate = ad4130_int_clk_recalc_rate,
1815 	.is_enabled = ad4130_int_clk_is_enabled,
1816 	.prepare = ad4130_int_clk_prepare,
1817 	.unprepare = ad4130_int_clk_unprepare,
1818 };
1819 
1820 static void ad4130_clk_del_provider(void *of_node)
1821 {
1822 	of_clk_del_provider(of_node);
1823 }
1824 
1825 static int ad4130_setup_int_clk(struct ad4130_state *st)
1826 {
1827 	struct device *dev = &st->spi->dev;
1828 	struct device_node *of_node = dev_of_node(dev);
1829 	struct clk_init_data init = {};
1830 	const char *clk_name;
1831 	struct clk *clk;
1832 	int ret;
1833 
1834 	if (st->int_pin_sel == AD4130_INT_PIN_CLK ||
1835 	    st->mclk_sel != AD4130_MCLK_76_8KHZ)
1836 		return 0;
1837 
1838 	if (!of_node)
1839 		return 0;
1840 
1841 	clk_name = of_node->name;
1842 	of_property_read_string(of_node, "clock-output-names", &clk_name);
1843 
1844 	init.name = clk_name;
1845 	init.ops = &ad4130_int_clk_ops;
1846 
1847 	st->int_clk_hw.init = &init;
1848 	clk = devm_clk_register(dev, &st->int_clk_hw);
1849 	if (IS_ERR(clk))
1850 		return PTR_ERR(clk);
1851 
1852 	ret = of_clk_add_provider(of_node, of_clk_src_simple_get, clk);
1853 	if (ret)
1854 		return ret;
1855 
1856 	return devm_add_action_or_reset(dev, ad4130_clk_del_provider, of_node);
1857 }
1858 
1859 static int ad4130_setup(struct iio_dev *indio_dev)
1860 {
1861 	struct ad4130_state *st = iio_priv(indio_dev);
1862 	struct device *dev = &st->spi->dev;
1863 	unsigned int int_ref_val;
1864 	unsigned long rate = AD4130_MCLK_FREQ_76_8KHZ;
1865 	unsigned int val;
1866 	unsigned int i;
1867 	int ret;
1868 
1869 	if (st->mclk_sel == AD4130_MCLK_153_6KHZ_EXT)
1870 		rate = AD4130_MCLK_FREQ_153_6KHZ;
1871 
1872 	ret = clk_set_rate(st->mclk, rate);
1873 	if (ret)
1874 		return ret;
1875 
1876 	ret = clk_prepare_enable(st->mclk);
1877 	if (ret)
1878 		return ret;
1879 
1880 	ret = devm_add_action_or_reset(dev, ad4130_clk_disable_unprepare,
1881 				       st->mclk);
1882 	if (ret)
1883 		return ret;
1884 
1885 	if (st->int_ref_uv == AD4130_INT_REF_2_5V)
1886 		int_ref_val = AD4130_INT_REF_VAL_2_5V;
1887 	else
1888 		int_ref_val = AD4130_INT_REF_VAL_1_25V;
1889 
1890 	/* Switch to SPI 4-wire mode. */
1891 	val =  FIELD_PREP(AD4130_ADC_CONTROL_CSB_EN_MASK, 1);
1892 	val |= FIELD_PREP(AD4130_ADC_CONTROL_BIPOLAR_MASK, st->bipolar);
1893 	val |= FIELD_PREP(AD4130_ADC_CONTROL_INT_REF_EN_MASK, st->int_ref_en);
1894 	val |= FIELD_PREP(AD4130_ADC_CONTROL_MODE_MASK, AD4130_MODE_IDLE);
1895 	val |= FIELD_PREP(AD4130_ADC_CONTROL_MCLK_SEL_MASK, st->mclk_sel);
1896 	val |= FIELD_PREP(AD4130_ADC_CONTROL_INT_REF_VAL_MASK, int_ref_val);
1897 
1898 	ret = regmap_write(st->regmap, AD4130_ADC_CONTROL_REG, val);
1899 	if (ret)
1900 		return ret;
1901 
1902 	/*
1903 	 * Configure unused GPIOs for output. If configured, the interrupt
1904 	 * function of P2 takes priority over the GPIO out function.
1905 	 */
1906 	val = 0;
1907 	for (i = 0; i < AD4130_MAX_GPIOS; i++)
1908 		if (st->pins_fn[i + AD4130_AIN2_P1] == AD4130_PIN_FN_NONE)
1909 			val |= FIELD_PREP(AD4130_IO_CONTROL_GPIO_CTRL_MASK, BIT(i));
1910 
1911 	val |= FIELD_PREP(AD4130_IO_CONTROL_INT_PIN_SEL_MASK, st->int_pin_sel);
1912 
1913 	ret = regmap_write(st->regmap, AD4130_IO_CONTROL_REG, val);
1914 	if (ret)
1915 		return ret;
1916 
1917 	val = 0;
1918 	for (i = 0; i < st->num_vbias_pins; i++)
1919 		val |= BIT(st->vbias_pins[i]);
1920 
1921 	ret = regmap_write(st->regmap, AD4130_VBIAS_REG, val);
1922 	if (ret)
1923 		return ret;
1924 
1925 	ret = regmap_update_bits(st->regmap, AD4130_FIFO_CONTROL_REG,
1926 				 AD4130_FIFO_CONTROL_HEADER_MASK, 0);
1927 	if (ret)
1928 		return ret;
1929 
1930 	/* FIFO watermark interrupt starts out as enabled, disable it. */
1931 	ret = ad4130_set_watermark_interrupt_en(st, false);
1932 	if (ret)
1933 		return ret;
1934 
1935 	/* Setup channels. */
1936 	for (i = 0; i < indio_dev->num_channels; i++) {
1937 		struct ad4130_chan_info *chan_info = &st->chans_info[i];
1938 		struct iio_chan_spec *chan = &st->chans[i];
1939 		unsigned int val;
1940 
1941 		val = FIELD_PREP(AD4130_CHANNEL_AINP_MASK, chan->channel) |
1942 		      FIELD_PREP(AD4130_CHANNEL_AINM_MASK, chan->channel2) |
1943 		      FIELD_PREP(AD4130_CHANNEL_IOUT1_MASK, chan_info->iout0) |
1944 		      FIELD_PREP(AD4130_CHANNEL_IOUT2_MASK, chan_info->iout1);
1945 
1946 		ret = regmap_write(st->regmap, AD4130_CHANNEL_X_REG(i), val);
1947 		if (ret)
1948 			return ret;
1949 	}
1950 
1951 	return 0;
1952 }
1953 
1954 static int ad4130_soft_reset(struct ad4130_state *st)
1955 {
1956 	int ret;
1957 
1958 	ret = spi_write(st->spi, st->reset_buf, sizeof(st->reset_buf));
1959 	if (ret)
1960 		return ret;
1961 
1962 	fsleep(AD4130_RESET_SLEEP_US);
1963 
1964 	return 0;
1965 }
1966 
1967 static void ad4130_disable_regulators(void *data)
1968 {
1969 	struct ad4130_state *st = data;
1970 
1971 	regulator_bulk_disable(ARRAY_SIZE(st->regulators), st->regulators);
1972 }
1973 
1974 static int ad4130_probe(struct spi_device *spi)
1975 {
1976 	struct device *dev = &spi->dev;
1977 	struct iio_dev *indio_dev;
1978 	struct ad4130_state *st;
1979 	int ret;
1980 
1981 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
1982 	if (!indio_dev)
1983 		return -ENOMEM;
1984 
1985 	st = iio_priv(indio_dev);
1986 
1987 	memset(st->reset_buf, 0xff, sizeof(st->reset_buf));
1988 	init_completion(&st->completion);
1989 	mutex_init(&st->lock);
1990 	st->spi = spi;
1991 
1992 	/*
1993 	 * Xfer:   [ XFR1 ] [         XFR2         ]
1994 	 * Master:  0x7D N   ......................
1995 	 * Slave:   ......   DATA1 DATA2 ... DATAN
1996 	 */
1997 	st->fifo_tx_buf[0] = AD4130_COMMS_READ_MASK | AD4130_FIFO_DATA_REG;
1998 	st->fifo_xfer[0].tx_buf = st->fifo_tx_buf;
1999 	st->fifo_xfer[0].len = sizeof(st->fifo_tx_buf);
2000 	st->fifo_xfer[1].rx_buf = st->fifo_rx_buf;
2001 	spi_message_init_with_transfers(&st->fifo_msg, st->fifo_xfer,
2002 					ARRAY_SIZE(st->fifo_xfer));
2003 
2004 	indio_dev->name = AD4130_NAME;
2005 	indio_dev->modes = INDIO_DIRECT_MODE;
2006 	indio_dev->info = &ad4130_info;
2007 
2008 	st->regmap = devm_regmap_init(dev, NULL, st, &ad4130_regmap_config);
2009 	if (IS_ERR(st->regmap))
2010 		return PTR_ERR(st->regmap);
2011 
2012 	st->regulators[0].supply = "avdd";
2013 	st->regulators[1].supply = "iovdd";
2014 	st->regulators[2].supply = "refin1";
2015 	st->regulators[3].supply = "refin2";
2016 
2017 	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(st->regulators),
2018 				      st->regulators);
2019 	if (ret)
2020 		return dev_err_probe(dev, ret, "Failed to get regulators\n");
2021 
2022 	ret = regulator_bulk_enable(ARRAY_SIZE(st->regulators), st->regulators);
2023 	if (ret)
2024 		return dev_err_probe(dev, ret, "Failed to enable regulators\n");
2025 
2026 	ret = devm_add_action_or_reset(dev, ad4130_disable_regulators, st);
2027 	if (ret)
2028 		return dev_err_probe(dev, ret,
2029 				     "Failed to add regulators disable action\n");
2030 
2031 	ret = ad4130_soft_reset(st);
2032 	if (ret)
2033 		return ret;
2034 
2035 	ret = ad4310_parse_fw(indio_dev);
2036 	if (ret)
2037 		return ret;
2038 
2039 	ret = ad4130_setup(indio_dev);
2040 	if (ret)
2041 		return ret;
2042 
2043 	ret = ad4130_setup_int_clk(st);
2044 	if (ret)
2045 		return ret;
2046 
2047 	ad4130_fill_scale_tbls(st);
2048 
2049 	st->gc.owner = THIS_MODULE;
2050 	st->gc.label = AD4130_NAME;
2051 	st->gc.base = -1;
2052 	st->gc.ngpio = AD4130_MAX_GPIOS;
2053 	st->gc.parent = dev;
2054 	st->gc.can_sleep = true;
2055 	st->gc.init_valid_mask = ad4130_gpio_init_valid_mask;
2056 	st->gc.get_direction = ad4130_gpio_get_direction;
2057 	st->gc.set = ad4130_gpio_set;
2058 
2059 	ret = devm_gpiochip_add_data(dev, &st->gc, st);
2060 	if (ret)
2061 		return ret;
2062 
2063 	ret = devm_iio_kfifo_buffer_setup_ext(dev, indio_dev,
2064 					      &ad4130_buffer_ops,
2065 					      ad4130_fifo_attributes);
2066 	if (ret)
2067 		return ret;
2068 
2069 	ret = devm_request_threaded_irq(dev, spi->irq, NULL,
2070 					ad4130_irq_handler, IRQF_ONESHOT,
2071 					indio_dev->name, indio_dev);
2072 	if (ret)
2073 		return dev_err_probe(dev, ret, "Failed to request irq\n");
2074 
2075 	/*
2076 	 * When the chip enters FIFO mode, IRQ polarity is inverted.
2077 	 * When the chip exits FIFO mode, IRQ polarity returns to normal.
2078 	 * See datasheet pages: 65, FIFO Watermark Interrupt section,
2079 	 * and 71, Bit Descriptions for STATUS Register, RDYB.
2080 	 * Cache the normal and inverted IRQ triggers to set them when
2081 	 * entering and exiting FIFO mode.
2082 	 */
2083 	st->irq_trigger = irq_get_trigger_type(spi->irq);
2084 	if (st->irq_trigger & IRQF_TRIGGER_RISING)
2085 		st->inv_irq_trigger = IRQF_TRIGGER_FALLING;
2086 	else if (st->irq_trigger & IRQF_TRIGGER_FALLING)
2087 		st->inv_irq_trigger = IRQF_TRIGGER_RISING;
2088 	else
2089 		return dev_err_probe(dev, -EINVAL, "Invalid irq flags: %u\n",
2090 				     st->irq_trigger);
2091 
2092 	return devm_iio_device_register(dev, indio_dev);
2093 }
2094 
2095 static const struct of_device_id ad4130_of_match[] = {
2096 	{
2097 		.compatible = "adi,ad4130",
2098 	},
2099 	{ }
2100 };
2101 MODULE_DEVICE_TABLE(of, ad4130_of_match);
2102 
2103 static struct spi_driver ad4130_driver = {
2104 	.driver = {
2105 		.name = AD4130_NAME,
2106 		.of_match_table = ad4130_of_match,
2107 	},
2108 	.probe = ad4130_probe,
2109 };
2110 module_spi_driver(ad4130_driver);
2111 
2112 MODULE_AUTHOR("Cosmin Tanislav <cosmin.tanislav@analog.com>");
2113 MODULE_DESCRIPTION("Analog Devices AD4130 SPI driver");
2114 MODULE_LICENSE("GPL");
2115