xref: /openbmc/linux/drivers/iio/adc/ad4130.c (revision b694e3c604e999343258c49e574abd7be012e726)
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 /*
227  * If you make adaptations in this struct, you most likely also have to adapt
228  * ad4130_setup_info_eq(), too.
229  */
230 struct ad4130_setup_info {
231 	unsigned int			iout0_val;
232 	unsigned int			iout1_val;
233 	unsigned int			burnout;
234 	unsigned int			pga;
235 	unsigned int			fs;
236 	u32				ref_sel;
237 	enum ad4130_filter_mode		filter_mode;
238 	bool				ref_bufp;
239 	bool				ref_bufm;
240 };
241 
242 struct ad4130_slot_info {
243 	struct ad4130_setup_info	setup;
244 	unsigned int			enabled_channels;
245 	unsigned int			channels;
246 };
247 
248 struct ad4130_chan_info {
249 	struct ad4130_setup_info	setup;
250 	u32				iout0;
251 	u32				iout1;
252 	int				slot;
253 	bool				enabled;
254 	bool				initialized;
255 };
256 
257 struct ad4130_filter_config {
258 	enum ad4130_filter_mode		filter_mode;
259 	unsigned int			odr_div;
260 	unsigned int			fs_max;
261 	enum iio_available_type		samp_freq_avail_type;
262 	int				samp_freq_avail_len;
263 	int				samp_freq_avail[3][2];
264 };
265 
266 struct ad4130_state {
267 	struct regmap			*regmap;
268 	struct spi_device		*spi;
269 	struct clk			*mclk;
270 	struct regulator_bulk_data	regulators[4];
271 	u32				irq_trigger;
272 	u32				inv_irq_trigger;
273 
274 	/*
275 	 * Synchronize access to members the of driver state, and ensure
276 	 * atomicity of consecutive regmap operations.
277 	 */
278 	struct mutex			lock;
279 	struct completion		completion;
280 
281 	struct iio_chan_spec		chans[AD4130_MAX_CHANNELS];
282 	struct ad4130_chan_info		chans_info[AD4130_MAX_CHANNELS];
283 	struct ad4130_slot_info		slots_info[AD4130_MAX_SETUPS];
284 	enum ad4130_pin_function	pins_fn[AD4130_MAX_ANALOG_PINS];
285 	u32				vbias_pins[AD4130_MAX_ANALOG_PINS];
286 	u32				num_vbias_pins;
287 	int				scale_tbls[AD4130_REF_SEL_MAX][AD4130_MAX_PGA][2];
288 	struct gpio_chip		gc;
289 	struct clk_hw			int_clk_hw;
290 
291 	u32			int_pin_sel;
292 	u32			int_ref_uv;
293 	u32			mclk_sel;
294 	bool			int_ref_en;
295 	bool			bipolar;
296 
297 	unsigned int		num_enabled_channels;
298 	unsigned int		effective_watermark;
299 	unsigned int		watermark;
300 
301 	struct spi_message	fifo_msg;
302 	struct spi_transfer	fifo_xfer[2];
303 
304 	/*
305 	 * DMA (thus cache coherency maintenance) requires any transfer
306 	 * buffers to live in their own cache lines. As the use of these
307 	 * buffers is synchronous, all of the buffers used for DMA in this
308 	 * driver may share a cache line.
309 	 */
310 	u8			reset_buf[AD4130_RESET_BUF_SIZE] __aligned(IIO_DMA_MINALIGN);
311 	u8			reg_write_tx_buf[4];
312 	u8			reg_read_tx_buf[1];
313 	u8			reg_read_rx_buf[3];
314 	u8			fifo_tx_buf[2];
315 	u8			fifo_rx_buf[AD4130_FIFO_SIZE *
316 					    AD4130_FIFO_MAX_SAMPLE_SIZE];
317 };
318 
319 static const char * const ad4130_int_pin_names[] = {
320 	[AD4130_INT_PIN_INT] = "int",
321 	[AD4130_INT_PIN_CLK] = "clk",
322 	[AD4130_INT_PIN_P2] = "p2",
323 	[AD4130_INT_PIN_DOUT] = "dout",
324 };
325 
326 static const unsigned int ad4130_iout_current_na_tbl[AD4130_IOUT_MAX] = {
327 	[AD4130_IOUT_OFF] = 0,
328 	[AD4130_IOUT_100NA] = 100,
329 	[AD4130_IOUT_10000NA] = 10000,
330 	[AD4130_IOUT_20000NA] = 20000,
331 	[AD4130_IOUT_50000NA] = 50000,
332 	[AD4130_IOUT_100000NA] = 100000,
333 	[AD4130_IOUT_150000NA] = 150000,
334 	[AD4130_IOUT_200000NA] = 200000,
335 };
336 
337 static const unsigned int ad4130_burnout_current_na_tbl[AD4130_BURNOUT_MAX] = {
338 	[AD4130_BURNOUT_OFF] = 0,
339 	[AD4130_BURNOUT_500NA] = 500,
340 	[AD4130_BURNOUT_2000NA] = 2000,
341 	[AD4130_BURNOUT_4000NA] = 4000,
342 };
343 
344 #define AD4130_VARIABLE_ODR_CONFIG(_filter_mode, _odr_div, _fs_max)	\
345 {									\
346 		.filter_mode = (_filter_mode),				\
347 		.odr_div = (_odr_div),					\
348 		.fs_max = (_fs_max),					\
349 		.samp_freq_avail_type = IIO_AVAIL_RANGE,		\
350 		.samp_freq_avail = {					\
351 			{ AD4130_MAX_ODR, (_odr_div) * (_fs_max) },	\
352 			{ AD4130_MAX_ODR, (_odr_div) * (_fs_max) },	\
353 			{ AD4130_MAX_ODR, (_odr_div) },			\
354 		},							\
355 }
356 
357 #define AD4130_FIXED_ODR_CONFIG(_filter_mode, _odr_div)			\
358 {									\
359 		.filter_mode = (_filter_mode),				\
360 		.odr_div = (_odr_div),					\
361 		.fs_max = AD4130_FILTER_SELECT_MIN,			\
362 		.samp_freq_avail_type = IIO_AVAIL_LIST,			\
363 		.samp_freq_avail_len = 1,				\
364 		.samp_freq_avail = {					\
365 			{ AD4130_MAX_ODR, (_odr_div) },			\
366 		},							\
367 }
368 
369 static const struct ad4130_filter_config ad4130_filter_configs[] = {
370 	AD4130_VARIABLE_ODR_CONFIG(AD4130_FILTER_SINC4,       1,  10),
371 	AD4130_VARIABLE_ODR_CONFIG(AD4130_FILTER_SINC4_SINC1, 11, 10),
372 	AD4130_VARIABLE_ODR_CONFIG(AD4130_FILTER_SINC3,       1,  2047),
373 	AD4130_VARIABLE_ODR_CONFIG(AD4130_FILTER_SINC3_REJ60, 1,  2047),
374 	AD4130_VARIABLE_ODR_CONFIG(AD4130_FILTER_SINC3_SINC1, 10, 2047),
375 	AD4130_FIXED_ODR_CONFIG(AD4130_FILTER_SINC3_PF1,      92),
376 	AD4130_FIXED_ODR_CONFIG(AD4130_FILTER_SINC3_PF2,      100),
377 	AD4130_FIXED_ODR_CONFIG(AD4130_FILTER_SINC3_PF3,      124),
378 	AD4130_FIXED_ODR_CONFIG(AD4130_FILTER_SINC3_PF4,      148),
379 };
380 
381 static const char * const ad4130_filter_modes_str[] = {
382 	[AD4130_FILTER_SINC4] = "sinc4",
383 	[AD4130_FILTER_SINC4_SINC1] = "sinc4+sinc1",
384 	[AD4130_FILTER_SINC3] = "sinc3",
385 	[AD4130_FILTER_SINC3_REJ60] = "sinc3+rej60",
386 	[AD4130_FILTER_SINC3_SINC1] = "sinc3+sinc1",
387 	[AD4130_FILTER_SINC3_PF1] = "sinc3+pf1",
388 	[AD4130_FILTER_SINC3_PF2] = "sinc3+pf2",
389 	[AD4130_FILTER_SINC3_PF3] = "sinc3+pf3",
390 	[AD4130_FILTER_SINC3_PF4] = "sinc3+pf4",
391 };
392 
ad4130_get_reg_size(struct ad4130_state * st,unsigned int reg,unsigned int * size)393 static int ad4130_get_reg_size(struct ad4130_state *st, unsigned int reg,
394 			       unsigned int *size)
395 {
396 	if (reg >= ARRAY_SIZE(ad4130_reg_size))
397 		return -EINVAL;
398 
399 	*size = ad4130_reg_size[reg];
400 
401 	return 0;
402 }
403 
ad4130_data_reg_size(struct ad4130_state * st)404 static unsigned int ad4130_data_reg_size(struct ad4130_state *st)
405 {
406 	unsigned int data_reg_size;
407 	int ret;
408 
409 	ret = ad4130_get_reg_size(st, AD4130_DATA_REG, &data_reg_size);
410 	if (ret)
411 		return 0;
412 
413 	return data_reg_size;
414 }
415 
ad4130_resolution(struct ad4130_state * st)416 static unsigned int ad4130_resolution(struct ad4130_state *st)
417 {
418 	return ad4130_data_reg_size(st) * BITS_PER_BYTE;
419 }
420 
ad4130_reg_write(void * context,unsigned int reg,unsigned int val)421 static int ad4130_reg_write(void *context, unsigned int reg, unsigned int val)
422 {
423 	struct ad4130_state *st = context;
424 	unsigned int size;
425 	int ret;
426 
427 	ret = ad4130_get_reg_size(st, reg, &size);
428 	if (ret)
429 		return ret;
430 
431 	st->reg_write_tx_buf[0] = reg;
432 
433 	switch (size) {
434 	case 3:
435 		put_unaligned_be24(val, &st->reg_write_tx_buf[1]);
436 		break;
437 	case 2:
438 		put_unaligned_be16(val, &st->reg_write_tx_buf[1]);
439 		break;
440 	case 1:
441 		st->reg_write_tx_buf[1] = val;
442 		break;
443 	default:
444 		return -EINVAL;
445 	}
446 
447 	return spi_write(st->spi, st->reg_write_tx_buf, size + 1);
448 }
449 
ad4130_reg_read(void * context,unsigned int reg,unsigned int * val)450 static int ad4130_reg_read(void *context, unsigned int reg, unsigned int *val)
451 {
452 	struct ad4130_state *st = context;
453 	struct spi_transfer t[] = {
454 		{
455 			.tx_buf = st->reg_read_tx_buf,
456 			.len = sizeof(st->reg_read_tx_buf),
457 		},
458 		{
459 			.rx_buf = st->reg_read_rx_buf,
460 		},
461 	};
462 	unsigned int size;
463 	int ret;
464 
465 	ret = ad4130_get_reg_size(st, reg, &size);
466 	if (ret)
467 		return ret;
468 
469 	st->reg_read_tx_buf[0] = AD4130_COMMS_READ_MASK | reg;
470 	t[1].len = size;
471 
472 	ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
473 	if (ret)
474 		return ret;
475 
476 	switch (size) {
477 	case 3:
478 		*val = get_unaligned_be24(st->reg_read_rx_buf);
479 		break;
480 	case 2:
481 		*val = get_unaligned_be16(st->reg_read_rx_buf);
482 		break;
483 	case 1:
484 		*val = st->reg_read_rx_buf[0];
485 		break;
486 	default:
487 		return -EINVAL;
488 	}
489 
490 	return 0;
491 }
492 
493 static const struct regmap_config ad4130_regmap_config = {
494 	.reg_read = ad4130_reg_read,
495 	.reg_write = ad4130_reg_write,
496 };
497 
ad4130_gpio_init_valid_mask(struct gpio_chip * gc,unsigned long * valid_mask,unsigned int ngpios)498 static int ad4130_gpio_init_valid_mask(struct gpio_chip *gc,
499 				       unsigned long *valid_mask,
500 				       unsigned int ngpios)
501 {
502 	struct ad4130_state *st = gpiochip_get_data(gc);
503 	unsigned int i;
504 
505 	/*
506 	 * Output-only GPIO functionality is available on pins AIN2 through
507 	 * AIN5. If these pins are used for anything else, do not expose them.
508 	 */
509 	for (i = 0; i < ngpios; i++) {
510 		unsigned int pin = i + AD4130_AIN2_P1;
511 		bool valid = st->pins_fn[pin] == AD4130_PIN_FN_NONE;
512 
513 		__assign_bit(i, valid_mask, valid);
514 	}
515 
516 	return 0;
517 }
518 
ad4130_gpio_get_direction(struct gpio_chip * gc,unsigned int offset)519 static int ad4130_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
520 {
521 	return GPIO_LINE_DIRECTION_OUT;
522 }
523 
ad4130_gpio_set(struct gpio_chip * gc,unsigned int offset,int value)524 static void ad4130_gpio_set(struct gpio_chip *gc, unsigned int offset,
525 			    int value)
526 {
527 	struct ad4130_state *st = gpiochip_get_data(gc);
528 	unsigned int mask = FIELD_PREP(AD4130_IO_CONTROL_GPIO_DATA_MASK,
529 				       BIT(offset));
530 
531 	regmap_update_bits(st->regmap, AD4130_IO_CONTROL_REG, mask,
532 			   value ? mask : 0);
533 }
534 
ad4130_set_mode(struct ad4130_state * st,enum ad4130_mode mode)535 static int ad4130_set_mode(struct ad4130_state *st, enum ad4130_mode mode)
536 {
537 	return regmap_update_bits(st->regmap, AD4130_ADC_CONTROL_REG,
538 				  AD4130_ADC_CONTROL_MODE_MASK,
539 				  FIELD_PREP(AD4130_ADC_CONTROL_MODE_MASK, mode));
540 }
541 
ad4130_set_watermark_interrupt_en(struct ad4130_state * st,bool en)542 static int ad4130_set_watermark_interrupt_en(struct ad4130_state *st, bool en)
543 {
544 	return regmap_update_bits(st->regmap, AD4130_FIFO_CONTROL_REG,
545 				  AD4130_FIFO_CONTROL_WM_INT_EN_MASK,
546 				  FIELD_PREP(AD4130_FIFO_CONTROL_WM_INT_EN_MASK, en));
547 }
548 
ad4130_watermark_reg_val(unsigned int val)549 static unsigned int ad4130_watermark_reg_val(unsigned int val)
550 {
551 	if (val == AD4130_FIFO_SIZE)
552 		val = AD4130_WATERMARK_256;
553 
554 	return val;
555 }
556 
ad4130_set_fifo_mode(struct ad4130_state * st,enum ad4130_fifo_mode mode)557 static int ad4130_set_fifo_mode(struct ad4130_state *st,
558 				enum ad4130_fifo_mode mode)
559 {
560 	return regmap_update_bits(st->regmap, AD4130_FIFO_CONTROL_REG,
561 				  AD4130_FIFO_CONTROL_MODE_MASK,
562 				  FIELD_PREP(AD4130_FIFO_CONTROL_MODE_MASK, mode));
563 }
564 
ad4130_push_fifo_data(struct iio_dev * indio_dev)565 static void ad4130_push_fifo_data(struct iio_dev *indio_dev)
566 {
567 	struct ad4130_state *st = iio_priv(indio_dev);
568 	unsigned int data_reg_size = ad4130_data_reg_size(st);
569 	unsigned int transfer_len = st->effective_watermark * data_reg_size;
570 	unsigned int set_size = st->num_enabled_channels * data_reg_size;
571 	unsigned int i;
572 	int ret;
573 
574 	st->fifo_tx_buf[1] = ad4130_watermark_reg_val(st->effective_watermark);
575 	st->fifo_xfer[1].len = transfer_len;
576 
577 	ret = spi_sync(st->spi, &st->fifo_msg);
578 	if (ret)
579 		return;
580 
581 	for (i = 0; i < transfer_len; i += set_size)
582 		iio_push_to_buffers(indio_dev, &st->fifo_rx_buf[i]);
583 }
584 
ad4130_irq_handler(int irq,void * private)585 static irqreturn_t ad4130_irq_handler(int irq, void *private)
586 {
587 	struct iio_dev *indio_dev = private;
588 	struct ad4130_state *st = iio_priv(indio_dev);
589 
590 	if (iio_buffer_enabled(indio_dev))
591 		ad4130_push_fifo_data(indio_dev);
592 	else
593 		complete(&st->completion);
594 
595 	return IRQ_HANDLED;
596 }
597 
ad4130_setup_info_eq(struct ad4130_setup_info * a,struct ad4130_setup_info * b)598 static bool ad4130_setup_info_eq(struct ad4130_setup_info *a,
599 				 struct ad4130_setup_info *b)
600 {
601 	/*
602 	 * This is just to make sure that the comparison is adapted after
603 	 * struct ad4130_setup_info was changed.
604 	 */
605 	static_assert(sizeof(*a) ==
606 		      sizeof(struct {
607 				     unsigned int iout0_val;
608 				     unsigned int iout1_val;
609 				     unsigned int burnout;
610 				     unsigned int pga;
611 				     unsigned int fs;
612 				     u32 ref_sel;
613 				     enum ad4130_filter_mode filter_mode;
614 				     bool ref_bufp;
615 				     bool ref_bufm;
616 			     }));
617 
618 	if (a->iout0_val != b->iout0_val ||
619 	    a->iout1_val != b->iout1_val ||
620 	    a->burnout != b->burnout ||
621 	    a->pga != b->pga ||
622 	    a->fs != b->fs ||
623 	    a->ref_sel != b->ref_sel ||
624 	    a->filter_mode != b->filter_mode ||
625 	    a->ref_bufp != b->ref_bufp ||
626 	    a->ref_bufm != b->ref_bufm)
627 		return false;
628 
629 	return true;
630 }
631 
ad4130_find_slot(struct ad4130_state * st,struct ad4130_setup_info * target_setup_info,unsigned int * slot,bool * overwrite)632 static int ad4130_find_slot(struct ad4130_state *st,
633 			    struct ad4130_setup_info *target_setup_info,
634 			    unsigned int *slot, bool *overwrite)
635 {
636 	unsigned int i;
637 
638 	*slot = AD4130_INVALID_SLOT;
639 	*overwrite = false;
640 
641 	for (i = 0; i < AD4130_MAX_SETUPS; i++) {
642 		struct ad4130_slot_info *slot_info = &st->slots_info[i];
643 
644 		/* Immediately accept a matching setup info. */
645 		if (ad4130_setup_info_eq(target_setup_info, &slot_info->setup)) {
646 			*slot = i;
647 			return 0;
648 		}
649 
650 		/* Ignore all setups which are used by enabled channels. */
651 		if (slot_info->enabled_channels)
652 			continue;
653 
654 		/* Find the least used slot. */
655 		if (*slot == AD4130_INVALID_SLOT ||
656 		    slot_info->channels < st->slots_info[*slot].channels)
657 			*slot = i;
658 	}
659 
660 	if (*slot == AD4130_INVALID_SLOT)
661 		return -EINVAL;
662 
663 	*overwrite = true;
664 
665 	return 0;
666 }
667 
ad4130_unlink_channel(struct ad4130_state * st,unsigned int channel)668 static void ad4130_unlink_channel(struct ad4130_state *st, unsigned int channel)
669 {
670 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
671 	struct ad4130_slot_info *slot_info = &st->slots_info[chan_info->slot];
672 
673 	chan_info->slot = AD4130_INVALID_SLOT;
674 	slot_info->channels--;
675 }
676 
ad4130_unlink_slot(struct ad4130_state * st,unsigned int slot)677 static int ad4130_unlink_slot(struct ad4130_state *st, unsigned int slot)
678 {
679 	unsigned int i;
680 
681 	for (i = 0; i < AD4130_MAX_CHANNELS; i++) {
682 		struct ad4130_chan_info *chan_info = &st->chans_info[i];
683 
684 		if (!chan_info->initialized || chan_info->slot != slot)
685 			continue;
686 
687 		ad4130_unlink_channel(st, i);
688 	}
689 
690 	return 0;
691 }
692 
ad4130_link_channel_slot(struct ad4130_state * st,unsigned int channel,unsigned int slot)693 static int ad4130_link_channel_slot(struct ad4130_state *st,
694 				    unsigned int channel, unsigned int slot)
695 {
696 	struct ad4130_slot_info *slot_info = &st->slots_info[slot];
697 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
698 	int ret;
699 
700 	ret = regmap_update_bits(st->regmap, AD4130_CHANNEL_X_REG(channel),
701 				 AD4130_CHANNEL_SETUP_MASK,
702 				 FIELD_PREP(AD4130_CHANNEL_SETUP_MASK, slot));
703 	if (ret)
704 		return ret;
705 
706 	chan_info->slot = slot;
707 	slot_info->channels++;
708 
709 	return 0;
710 }
711 
ad4130_write_slot_setup(struct ad4130_state * st,unsigned int slot,struct ad4130_setup_info * setup_info)712 static int ad4130_write_slot_setup(struct ad4130_state *st,
713 				   unsigned int slot,
714 				   struct ad4130_setup_info *setup_info)
715 {
716 	unsigned int val;
717 	int ret;
718 
719 	val = FIELD_PREP(AD4130_CONFIG_IOUT1_VAL_MASK, setup_info->iout0_val) |
720 	      FIELD_PREP(AD4130_CONFIG_IOUT1_VAL_MASK, setup_info->iout1_val) |
721 	      FIELD_PREP(AD4130_CONFIG_BURNOUT_MASK, setup_info->burnout) |
722 	      FIELD_PREP(AD4130_CONFIG_REF_BUFP_MASK, setup_info->ref_bufp) |
723 	      FIELD_PREP(AD4130_CONFIG_REF_BUFM_MASK, setup_info->ref_bufm) |
724 	      FIELD_PREP(AD4130_CONFIG_REF_SEL_MASK, setup_info->ref_sel) |
725 	      FIELD_PREP(AD4130_CONFIG_PGA_MASK, setup_info->pga);
726 
727 	ret = regmap_write(st->regmap, AD4130_CONFIG_X_REG(slot), val);
728 	if (ret)
729 		return ret;
730 
731 	val = FIELD_PREP(AD4130_FILTER_MODE_MASK, setup_info->filter_mode) |
732 	      FIELD_PREP(AD4130_FILTER_SELECT_MASK, setup_info->fs);
733 
734 	ret = regmap_write(st->regmap, AD4130_FILTER_X_REG(slot), val);
735 	if (ret)
736 		return ret;
737 
738 	memcpy(&st->slots_info[slot].setup, setup_info, sizeof(*setup_info));
739 
740 	return 0;
741 }
742 
ad4130_write_channel_setup(struct ad4130_state * st,unsigned int channel,bool on_enable)743 static int ad4130_write_channel_setup(struct ad4130_state *st,
744 				      unsigned int channel, bool on_enable)
745 {
746 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
747 	struct ad4130_setup_info *setup_info = &chan_info->setup;
748 	bool overwrite;
749 	int slot;
750 	int ret;
751 
752 	/*
753 	 * The following cases need to be handled.
754 	 *
755 	 * 1. Enabled and linked channel with setup changes:
756 	 *    - Find a slot. If not possible, return error.
757 	 *    - Unlink channel from current slot.
758 	 *    - If the slot has channels linked to it, unlink all channels, and
759 	 *      write the new setup to it.
760 	 *    - Link channel to new slot.
761 	 *
762 	 * 2. Soon to be enabled and unlinked channel:
763 	 *    - Find a slot. If not possible, return error.
764 	 *    - If the slot has channels linked to it, unlink all channels, and
765 	 *      write the new setup to it.
766 	 *    - Link channel to the slot.
767 	 *
768 	 * 3. Disabled and linked channel with setup changes:
769 	 *    - Unlink channel from current slot.
770 	 *
771 	 * 4. Soon to be enabled and linked channel:
772 	 * 5. Disabled and unlinked channel with setup changes:
773 	 *    - Do nothing.
774 	 */
775 
776 	/* Case 4 */
777 	if (on_enable && chan_info->slot != AD4130_INVALID_SLOT)
778 		return 0;
779 
780 	if (!on_enable && !chan_info->enabled) {
781 		if (chan_info->slot != AD4130_INVALID_SLOT)
782 			/* Case 3 */
783 			ad4130_unlink_channel(st, channel);
784 
785 		/* Cases 3 & 5 */
786 		return 0;
787 	}
788 
789 	/* Cases 1 & 2 */
790 	ret = ad4130_find_slot(st, setup_info, &slot, &overwrite);
791 	if (ret)
792 		return ret;
793 
794 	if (chan_info->slot != AD4130_INVALID_SLOT)
795 		/* Case 1 */
796 		ad4130_unlink_channel(st, channel);
797 
798 	if (overwrite) {
799 		ret = ad4130_unlink_slot(st, slot);
800 		if (ret)
801 			return ret;
802 
803 		ret = ad4130_write_slot_setup(st, slot, setup_info);
804 		if (ret)
805 			return ret;
806 	}
807 
808 	return ad4130_link_channel_slot(st, channel, slot);
809 }
810 
ad4130_set_channel_enable(struct ad4130_state * st,unsigned int channel,bool status)811 static int ad4130_set_channel_enable(struct ad4130_state *st,
812 				     unsigned int channel, bool status)
813 {
814 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
815 	struct ad4130_slot_info *slot_info;
816 	int ret;
817 
818 	if (chan_info->enabled == status)
819 		return 0;
820 
821 	if (status) {
822 		ret = ad4130_write_channel_setup(st, channel, true);
823 		if (ret)
824 			return ret;
825 	}
826 
827 	slot_info = &st->slots_info[chan_info->slot];
828 
829 	ret = regmap_update_bits(st->regmap, AD4130_CHANNEL_X_REG(channel),
830 				 AD4130_CHANNEL_EN_MASK,
831 				 FIELD_PREP(AD4130_CHANNEL_EN_MASK, status));
832 	if (ret)
833 		return ret;
834 
835 	slot_info->enabled_channels += status ? 1 : -1;
836 	chan_info->enabled = status;
837 
838 	return 0;
839 }
840 
841 /*
842  * Table 58. FILTER_MODE_n bits and Filter Types of the datasheet describes
843  * the relation between filter mode, ODR and FS.
844  *
845  * Notice that the max ODR of each filter mode is not necessarily the
846  * absolute max ODR supported by the chip.
847  *
848  * The ODR divider is not explicitly specified, but it can be deduced based
849  * on the ODR range of each filter mode.
850  *
851  * For example, for Sinc4+Sinc1, max ODR is 218.18. That means that the
852  * absolute max ODR is divided by 11 to achieve the max ODR of this filter
853  * mode.
854  *
855  * The formulas for converting between ODR and FS for a specific filter
856  * mode can be deduced from the same table.
857  *
858  * Notice that FS = 1 actually means max ODR, and that ODR decreases by
859  * (maximum ODR / maximum FS) for each increment of FS.
860  *
861  * odr = MAX_ODR / odr_div * (1 - (fs - 1) / fs_max) <=>
862  * odr = MAX_ODR * (1 - (fs - 1) / fs_max) / odr_div <=>
863  * odr = MAX_ODR * (1 - (fs - 1) / fs_max) / odr_div <=>
864  * odr = MAX_ODR * (fs_max - fs + 1) / (fs_max * odr_div)
865  * (used in ad4130_fs_to_freq)
866  *
867  * For the opposite formula, FS can be extracted from the last one.
868  *
869  * MAX_ODR * (fs_max - fs + 1) = fs_max * odr_div * odr <=>
870  * fs_max - fs + 1 = fs_max * odr_div * odr / MAX_ODR <=>
871  * fs = 1 + fs_max - fs_max * odr_div * odr / MAX_ODR
872  * (used in ad4130_fs_to_freq)
873  */
874 
ad4130_freq_to_fs(enum ad4130_filter_mode filter_mode,int val,int val2,unsigned int * fs)875 static void ad4130_freq_to_fs(enum ad4130_filter_mode filter_mode,
876 			      int val, int val2, unsigned int *fs)
877 {
878 	const struct ad4130_filter_config *filter_config =
879 		&ad4130_filter_configs[filter_mode];
880 	u64 dividend, divisor;
881 	int temp;
882 
883 	dividend = filter_config->fs_max * filter_config->odr_div *
884 		   ((u64)val * NANO + val2);
885 	divisor = (u64)AD4130_MAX_ODR * NANO;
886 
887 	temp = AD4130_FILTER_SELECT_MIN + filter_config->fs_max -
888 	       DIV64_U64_ROUND_CLOSEST(dividend, divisor);
889 
890 	if (temp < AD4130_FILTER_SELECT_MIN)
891 		temp = AD4130_FILTER_SELECT_MIN;
892 	else if (temp > filter_config->fs_max)
893 		temp = filter_config->fs_max;
894 
895 	*fs = temp;
896 }
897 
ad4130_fs_to_freq(enum ad4130_filter_mode filter_mode,unsigned int fs,int * val,int * val2)898 static void ad4130_fs_to_freq(enum ad4130_filter_mode filter_mode,
899 			      unsigned int fs, int *val, int *val2)
900 {
901 	const struct ad4130_filter_config *filter_config =
902 		&ad4130_filter_configs[filter_mode];
903 	unsigned int dividend, divisor;
904 	u64 temp;
905 
906 	dividend = (filter_config->fs_max - fs + AD4130_FILTER_SELECT_MIN) *
907 		   AD4130_MAX_ODR;
908 	divisor = filter_config->fs_max * filter_config->odr_div;
909 
910 	temp = div_u64((u64)dividend * NANO, divisor);
911 	*val = div_u64_rem(temp, NANO, val2);
912 }
913 
ad4130_set_filter_mode(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,unsigned int val)914 static int ad4130_set_filter_mode(struct iio_dev *indio_dev,
915 				  const struct iio_chan_spec *chan,
916 				  unsigned int val)
917 {
918 	struct ad4130_state *st = iio_priv(indio_dev);
919 	unsigned int channel = chan->scan_index;
920 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
921 	struct ad4130_setup_info *setup_info = &chan_info->setup;
922 	enum ad4130_filter_mode old_filter_mode;
923 	int freq_val, freq_val2;
924 	unsigned int old_fs;
925 	int ret = 0;
926 
927 	mutex_lock(&st->lock);
928 	if (setup_info->filter_mode == val)
929 		goto out;
930 
931 	old_fs = setup_info->fs;
932 	old_filter_mode = setup_info->filter_mode;
933 
934 	/*
935 	 * When switching between filter modes, try to match the ODR as
936 	 * close as possible. To do this, convert the current FS into ODR
937 	 * using the old filter mode, then convert it back into FS using
938 	 * the new filter mode.
939 	 */
940 	ad4130_fs_to_freq(setup_info->filter_mode, setup_info->fs,
941 			  &freq_val, &freq_val2);
942 
943 	ad4130_freq_to_fs(val, freq_val, freq_val2, &setup_info->fs);
944 
945 	setup_info->filter_mode = val;
946 
947 	ret = ad4130_write_channel_setup(st, channel, false);
948 	if (ret) {
949 		setup_info->fs = old_fs;
950 		setup_info->filter_mode = old_filter_mode;
951 	}
952 
953  out:
954 	mutex_unlock(&st->lock);
955 
956 	return ret;
957 }
958 
ad4130_get_filter_mode(struct iio_dev * indio_dev,const struct iio_chan_spec * chan)959 static int ad4130_get_filter_mode(struct iio_dev *indio_dev,
960 				  const struct iio_chan_spec *chan)
961 {
962 	struct ad4130_state *st = iio_priv(indio_dev);
963 	unsigned int channel = chan->scan_index;
964 	struct ad4130_setup_info *setup_info = &st->chans_info[channel].setup;
965 	enum ad4130_filter_mode filter_mode;
966 
967 	mutex_lock(&st->lock);
968 	filter_mode = setup_info->filter_mode;
969 	mutex_unlock(&st->lock);
970 
971 	return filter_mode;
972 }
973 
974 static const struct iio_enum ad4130_filter_mode_enum = {
975 	.items = ad4130_filter_modes_str,
976 	.num_items = ARRAY_SIZE(ad4130_filter_modes_str),
977 	.set = ad4130_set_filter_mode,
978 	.get = ad4130_get_filter_mode,
979 };
980 
981 static const struct iio_chan_spec_ext_info ad4130_filter_mode_ext_info[] = {
982 	IIO_ENUM("filter_mode", IIO_SEPARATE, &ad4130_filter_mode_enum),
983 	IIO_ENUM_AVAILABLE("filter_mode", IIO_SHARED_BY_TYPE,
984 			   &ad4130_filter_mode_enum),
985 	{ }
986 };
987 
988 static const struct iio_chan_spec ad4130_channel_template = {
989 	.type = IIO_VOLTAGE,
990 	.indexed = 1,
991 	.differential = 1,
992 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
993 			      BIT(IIO_CHAN_INFO_SCALE) |
994 			      BIT(IIO_CHAN_INFO_OFFSET) |
995 			      BIT(IIO_CHAN_INFO_SAMP_FREQ),
996 	.info_mask_separate_available = BIT(IIO_CHAN_INFO_SCALE) |
997 					BIT(IIO_CHAN_INFO_SAMP_FREQ),
998 	.ext_info = ad4130_filter_mode_ext_info,
999 	.scan_type = {
1000 		.sign = 'u',
1001 		.endianness = IIO_BE,
1002 	},
1003 };
1004 
ad4130_set_channel_pga(struct ad4130_state * st,unsigned int channel,int val,int val2)1005 static int ad4130_set_channel_pga(struct ad4130_state *st, unsigned int channel,
1006 				  int val, int val2)
1007 {
1008 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
1009 	struct ad4130_setup_info *setup_info = &chan_info->setup;
1010 	unsigned int pga, old_pga;
1011 	int ret = 0;
1012 
1013 	for (pga = 0; pga < AD4130_MAX_PGA; pga++)
1014 		if (val == st->scale_tbls[setup_info->ref_sel][pga][0] &&
1015 		    val2 == st->scale_tbls[setup_info->ref_sel][pga][1])
1016 			break;
1017 
1018 	if (pga == AD4130_MAX_PGA)
1019 		return -EINVAL;
1020 
1021 	mutex_lock(&st->lock);
1022 	if (pga == setup_info->pga)
1023 		goto out;
1024 
1025 	old_pga = setup_info->pga;
1026 	setup_info->pga = pga;
1027 
1028 	ret = ad4130_write_channel_setup(st, channel, false);
1029 	if (ret)
1030 		setup_info->pga = old_pga;
1031 
1032 out:
1033 	mutex_unlock(&st->lock);
1034 
1035 	return ret;
1036 }
1037 
ad4130_set_channel_freq(struct ad4130_state * st,unsigned int channel,int val,int val2)1038 static int ad4130_set_channel_freq(struct ad4130_state *st,
1039 				   unsigned int channel, int val, int val2)
1040 {
1041 	struct ad4130_chan_info *chan_info = &st->chans_info[channel];
1042 	struct ad4130_setup_info *setup_info = &chan_info->setup;
1043 	unsigned int fs, old_fs;
1044 	int ret = 0;
1045 
1046 	mutex_lock(&st->lock);
1047 	old_fs = setup_info->fs;
1048 
1049 	ad4130_freq_to_fs(setup_info->filter_mode, val, val2, &fs);
1050 
1051 	if (fs == setup_info->fs)
1052 		goto out;
1053 
1054 	setup_info->fs = fs;
1055 
1056 	ret = ad4130_write_channel_setup(st, channel, false);
1057 	if (ret)
1058 		setup_info->fs = old_fs;
1059 
1060 out:
1061 	mutex_unlock(&st->lock);
1062 
1063 	return ret;
1064 }
1065 
_ad4130_read_sample(struct iio_dev * indio_dev,unsigned int channel,int * val)1066 static int _ad4130_read_sample(struct iio_dev *indio_dev, unsigned int channel,
1067 			       int *val)
1068 {
1069 	struct ad4130_state *st = iio_priv(indio_dev);
1070 	int ret;
1071 
1072 	ret = ad4130_set_channel_enable(st, channel, true);
1073 	if (ret)
1074 		return ret;
1075 
1076 	reinit_completion(&st->completion);
1077 
1078 	ret = ad4130_set_mode(st, AD4130_MODE_CONTINUOUS);
1079 	if (ret)
1080 		return ret;
1081 
1082 	ret = wait_for_completion_timeout(&st->completion,
1083 					  msecs_to_jiffies(1000));
1084 	if (!ret)
1085 		return -ETIMEDOUT;
1086 
1087 	ret = ad4130_set_mode(st, AD4130_MODE_IDLE);
1088 	if (ret)
1089 		return ret;
1090 
1091 	ret = regmap_read(st->regmap, AD4130_DATA_REG, val);
1092 	if (ret)
1093 		return ret;
1094 
1095 	ret = ad4130_set_channel_enable(st, channel, false);
1096 	if (ret)
1097 		return ret;
1098 
1099 	return IIO_VAL_INT;
1100 }
1101 
ad4130_read_sample(struct iio_dev * indio_dev,unsigned int channel,int * val)1102 static int ad4130_read_sample(struct iio_dev *indio_dev, unsigned int channel,
1103 			      int *val)
1104 {
1105 	struct ad4130_state *st = iio_priv(indio_dev);
1106 	int ret;
1107 
1108 	ret = iio_device_claim_direct_mode(indio_dev);
1109 	if (ret)
1110 		return ret;
1111 
1112 	mutex_lock(&st->lock);
1113 	ret = _ad4130_read_sample(indio_dev, channel, val);
1114 	mutex_unlock(&st->lock);
1115 
1116 	iio_device_release_direct_mode(indio_dev);
1117 
1118 	return ret;
1119 }
1120 
ad4130_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long info)1121 static int ad4130_read_raw(struct iio_dev *indio_dev,
1122 			   struct iio_chan_spec const *chan,
1123 			   int *val, int *val2, long info)
1124 {
1125 	struct ad4130_state *st = iio_priv(indio_dev);
1126 	unsigned int channel = chan->scan_index;
1127 	struct ad4130_setup_info *setup_info = &st->chans_info[channel].setup;
1128 
1129 	switch (info) {
1130 	case IIO_CHAN_INFO_RAW:
1131 		return ad4130_read_sample(indio_dev, channel, val);
1132 	case IIO_CHAN_INFO_SCALE:
1133 		mutex_lock(&st->lock);
1134 		*val = st->scale_tbls[setup_info->ref_sel][setup_info->pga][0];
1135 		*val2 = st->scale_tbls[setup_info->ref_sel][setup_info->pga][1];
1136 		mutex_unlock(&st->lock);
1137 
1138 		return IIO_VAL_INT_PLUS_NANO;
1139 	case IIO_CHAN_INFO_OFFSET:
1140 		*val = st->bipolar ? -BIT(chan->scan_type.realbits - 1) : 0;
1141 
1142 		return IIO_VAL_INT;
1143 	case IIO_CHAN_INFO_SAMP_FREQ:
1144 		mutex_lock(&st->lock);
1145 		ad4130_fs_to_freq(setup_info->filter_mode, setup_info->fs,
1146 				  val, val2);
1147 		mutex_unlock(&st->lock);
1148 
1149 		return IIO_VAL_INT_PLUS_NANO;
1150 	default:
1151 		return -EINVAL;
1152 	}
1153 }
1154 
ad4130_read_avail(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,const int ** vals,int * type,int * length,long info)1155 static int ad4130_read_avail(struct iio_dev *indio_dev,
1156 			     struct iio_chan_spec const *chan,
1157 			     const int **vals, int *type, int *length,
1158 			     long info)
1159 {
1160 	struct ad4130_state *st = iio_priv(indio_dev);
1161 	unsigned int channel = chan->scan_index;
1162 	struct ad4130_setup_info *setup_info = &st->chans_info[channel].setup;
1163 	const struct ad4130_filter_config *filter_config;
1164 
1165 	switch (info) {
1166 	case IIO_CHAN_INFO_SCALE:
1167 		*vals = (int *)st->scale_tbls[setup_info->ref_sel];
1168 		*length = ARRAY_SIZE(st->scale_tbls[setup_info->ref_sel]) * 2;
1169 
1170 		*type = IIO_VAL_INT_PLUS_NANO;
1171 
1172 		return IIO_AVAIL_LIST;
1173 	case IIO_CHAN_INFO_SAMP_FREQ:
1174 		mutex_lock(&st->lock);
1175 		filter_config = &ad4130_filter_configs[setup_info->filter_mode];
1176 		mutex_unlock(&st->lock);
1177 
1178 		*vals = (int *)filter_config->samp_freq_avail;
1179 		*length = filter_config->samp_freq_avail_len * 2;
1180 		*type = IIO_VAL_FRACTIONAL;
1181 
1182 		return filter_config->samp_freq_avail_type;
1183 	default:
1184 		return -EINVAL;
1185 	}
1186 }
1187 
ad4130_write_raw_get_fmt(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,long info)1188 static int ad4130_write_raw_get_fmt(struct iio_dev *indio_dev,
1189 				    struct iio_chan_spec const *chan,
1190 				    long info)
1191 {
1192 	switch (info) {
1193 	case IIO_CHAN_INFO_SCALE:
1194 	case IIO_CHAN_INFO_SAMP_FREQ:
1195 		return IIO_VAL_INT_PLUS_NANO;
1196 	default:
1197 		return -EINVAL;
1198 	}
1199 }
1200 
ad4130_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long info)1201 static int ad4130_write_raw(struct iio_dev *indio_dev,
1202 			    struct iio_chan_spec const *chan,
1203 			    int val, int val2, long info)
1204 {
1205 	struct ad4130_state *st = iio_priv(indio_dev);
1206 	unsigned int channel = chan->scan_index;
1207 
1208 	switch (info) {
1209 	case IIO_CHAN_INFO_SCALE:
1210 		return ad4130_set_channel_pga(st, channel, val, val2);
1211 	case IIO_CHAN_INFO_SAMP_FREQ:
1212 		return ad4130_set_channel_freq(st, channel, val, val2);
1213 	default:
1214 		return -EINVAL;
1215 	}
1216 }
1217 
ad4130_reg_access(struct iio_dev * indio_dev,unsigned int reg,unsigned int writeval,unsigned int * readval)1218 static int ad4130_reg_access(struct iio_dev *indio_dev, unsigned int reg,
1219 			     unsigned int writeval, unsigned int *readval)
1220 {
1221 	struct ad4130_state *st = iio_priv(indio_dev);
1222 
1223 	if (readval)
1224 		return regmap_read(st->regmap, reg, readval);
1225 
1226 	return regmap_write(st->regmap, reg, writeval);
1227 }
1228 
ad4130_update_scan_mode(struct iio_dev * indio_dev,const unsigned long * scan_mask)1229 static int ad4130_update_scan_mode(struct iio_dev *indio_dev,
1230 				   const unsigned long *scan_mask)
1231 {
1232 	struct ad4130_state *st = iio_priv(indio_dev);
1233 	unsigned int channel;
1234 	unsigned int val = 0;
1235 	int ret;
1236 
1237 	mutex_lock(&st->lock);
1238 
1239 	for_each_set_bit(channel, scan_mask, indio_dev->num_channels) {
1240 		ret = ad4130_set_channel_enable(st, channel, true);
1241 		if (ret)
1242 			goto out;
1243 
1244 		val++;
1245 	}
1246 
1247 	st->num_enabled_channels = val;
1248 
1249 out:
1250 	mutex_unlock(&st->lock);
1251 
1252 	return 0;
1253 }
1254 
ad4130_set_fifo_watermark(struct iio_dev * indio_dev,unsigned int val)1255 static int ad4130_set_fifo_watermark(struct iio_dev *indio_dev, unsigned int val)
1256 {
1257 	struct ad4130_state *st = iio_priv(indio_dev);
1258 	unsigned int eff;
1259 	int ret;
1260 
1261 	if (val > AD4130_FIFO_SIZE)
1262 		return -EINVAL;
1263 
1264 	eff = val * st->num_enabled_channels;
1265 	if (eff > AD4130_FIFO_SIZE)
1266 		/*
1267 		 * Always set watermark to a multiple of the number of
1268 		 * enabled channels to avoid making the FIFO unaligned.
1269 		 */
1270 		eff = rounddown(AD4130_FIFO_SIZE, st->num_enabled_channels);
1271 
1272 	mutex_lock(&st->lock);
1273 
1274 	ret = regmap_update_bits(st->regmap, AD4130_FIFO_CONTROL_REG,
1275 				 AD4130_FIFO_CONTROL_WM_MASK,
1276 				 FIELD_PREP(AD4130_FIFO_CONTROL_WM_MASK,
1277 					    ad4130_watermark_reg_val(eff)));
1278 	if (ret)
1279 		goto out;
1280 
1281 	st->effective_watermark = eff;
1282 	st->watermark = val;
1283 
1284 out:
1285 	mutex_unlock(&st->lock);
1286 
1287 	return ret;
1288 }
1289 
1290 static const struct iio_info ad4130_info = {
1291 	.read_raw = ad4130_read_raw,
1292 	.read_avail = ad4130_read_avail,
1293 	.write_raw_get_fmt = ad4130_write_raw_get_fmt,
1294 	.write_raw = ad4130_write_raw,
1295 	.update_scan_mode = ad4130_update_scan_mode,
1296 	.hwfifo_set_watermark = ad4130_set_fifo_watermark,
1297 	.debugfs_reg_access = ad4130_reg_access,
1298 };
1299 
ad4130_buffer_postenable(struct iio_dev * indio_dev)1300 static int ad4130_buffer_postenable(struct iio_dev *indio_dev)
1301 {
1302 	struct ad4130_state *st = iio_priv(indio_dev);
1303 	int ret;
1304 
1305 	mutex_lock(&st->lock);
1306 
1307 	ret = ad4130_set_watermark_interrupt_en(st, true);
1308 	if (ret)
1309 		goto out;
1310 
1311 	ret = irq_set_irq_type(st->spi->irq, st->inv_irq_trigger);
1312 	if (ret)
1313 		goto out;
1314 
1315 	ret = ad4130_set_fifo_mode(st, AD4130_FIFO_MODE_WM);
1316 	if (ret)
1317 		goto out;
1318 
1319 	ret = ad4130_set_mode(st, AD4130_MODE_CONTINUOUS);
1320 
1321 out:
1322 	mutex_unlock(&st->lock);
1323 
1324 	return ret;
1325 }
1326 
ad4130_buffer_predisable(struct iio_dev * indio_dev)1327 static int ad4130_buffer_predisable(struct iio_dev *indio_dev)
1328 {
1329 	struct ad4130_state *st = iio_priv(indio_dev);
1330 	unsigned int i;
1331 	int ret;
1332 
1333 	mutex_lock(&st->lock);
1334 
1335 	ret = ad4130_set_mode(st, AD4130_MODE_IDLE);
1336 	if (ret)
1337 		goto out;
1338 
1339 	ret = irq_set_irq_type(st->spi->irq, st->irq_trigger);
1340 	if (ret)
1341 		goto out;
1342 
1343 	ret = ad4130_set_fifo_mode(st, AD4130_FIFO_MODE_DISABLED);
1344 	if (ret)
1345 		goto out;
1346 
1347 	ret = ad4130_set_watermark_interrupt_en(st, false);
1348 	if (ret)
1349 		goto out;
1350 
1351 	/*
1352 	 * update_scan_mode() is not called in the disable path, disable all
1353 	 * channels here.
1354 	 */
1355 	for (i = 0; i < indio_dev->num_channels; i++) {
1356 		ret = ad4130_set_channel_enable(st, i, false);
1357 		if (ret)
1358 			goto out;
1359 	}
1360 
1361 out:
1362 	mutex_unlock(&st->lock);
1363 
1364 	return ret;
1365 }
1366 
1367 static const struct iio_buffer_setup_ops ad4130_buffer_ops = {
1368 	.postenable = ad4130_buffer_postenable,
1369 	.predisable = ad4130_buffer_predisable,
1370 };
1371 
hwfifo_watermark_show(struct device * dev,struct device_attribute * attr,char * buf)1372 static ssize_t hwfifo_watermark_show(struct device *dev,
1373 				     struct device_attribute *attr, char *buf)
1374 {
1375 	struct ad4130_state *st = iio_priv(dev_to_iio_dev(dev));
1376 	unsigned int val;
1377 
1378 	mutex_lock(&st->lock);
1379 	val = st->watermark;
1380 	mutex_unlock(&st->lock);
1381 
1382 	return sysfs_emit(buf, "%d\n", val);
1383 }
1384 
hwfifo_enabled_show(struct device * dev,struct device_attribute * attr,char * buf)1385 static ssize_t hwfifo_enabled_show(struct device *dev,
1386 				   struct device_attribute *attr, char *buf)
1387 {
1388 	struct ad4130_state *st = iio_priv(dev_to_iio_dev(dev));
1389 	unsigned int val;
1390 	int ret;
1391 
1392 	ret = regmap_read(st->regmap, AD4130_FIFO_CONTROL_REG, &val);
1393 	if (ret)
1394 		return ret;
1395 
1396 	val = FIELD_GET(AD4130_FIFO_CONTROL_MODE_MASK, val);
1397 
1398 	return sysfs_emit(buf, "%d\n", val != AD4130_FIFO_MODE_DISABLED);
1399 }
1400 
hwfifo_watermark_min_show(struct device * dev,struct device_attribute * attr,char * buf)1401 static ssize_t hwfifo_watermark_min_show(struct device *dev,
1402 					 struct device_attribute *attr,
1403 					 char *buf)
1404 {
1405 	return sysfs_emit(buf, "%s\n", "1");
1406 }
1407 
hwfifo_watermark_max_show(struct device * dev,struct device_attribute * attr,char * buf)1408 static ssize_t hwfifo_watermark_max_show(struct device *dev,
1409 					 struct device_attribute *attr,
1410 					 char *buf)
1411 {
1412 	return sysfs_emit(buf, "%s\n", __stringify(AD4130_FIFO_SIZE));
1413 }
1414 
1415 static IIO_DEVICE_ATTR_RO(hwfifo_watermark_min, 0);
1416 static IIO_DEVICE_ATTR_RO(hwfifo_watermark_max, 0);
1417 static IIO_DEVICE_ATTR_RO(hwfifo_watermark, 0);
1418 static IIO_DEVICE_ATTR_RO(hwfifo_enabled, 0);
1419 
1420 static const struct iio_dev_attr *ad4130_fifo_attributes[] = {
1421 	&iio_dev_attr_hwfifo_watermark_min,
1422 	&iio_dev_attr_hwfifo_watermark_max,
1423 	&iio_dev_attr_hwfifo_watermark,
1424 	&iio_dev_attr_hwfifo_enabled,
1425 	NULL
1426 };
1427 
_ad4130_find_table_index(const unsigned int * tbl,size_t len,unsigned int val)1428 static int _ad4130_find_table_index(const unsigned int *tbl, size_t len,
1429 				    unsigned int val)
1430 {
1431 	unsigned int i;
1432 
1433 	for (i = 0; i < len; i++)
1434 		if (tbl[i] == val)
1435 			return i;
1436 
1437 	return -EINVAL;
1438 }
1439 
1440 #define ad4130_find_table_index(table, val) \
1441 	_ad4130_find_table_index(table, ARRAY_SIZE(table), val)
1442 
ad4130_get_ref_voltage(struct ad4130_state * st,enum ad4130_ref_sel ref_sel)1443 static int ad4130_get_ref_voltage(struct ad4130_state *st,
1444 				  enum ad4130_ref_sel ref_sel)
1445 {
1446 	switch (ref_sel) {
1447 	case AD4130_REF_REFIN1:
1448 		return regulator_get_voltage(st->regulators[2].consumer);
1449 	case AD4130_REF_REFIN2:
1450 		return regulator_get_voltage(st->regulators[3].consumer);
1451 	case AD4130_REF_AVDD_AVSS:
1452 		return regulator_get_voltage(st->regulators[0].consumer);
1453 	case AD4130_REF_REFOUT_AVSS:
1454 		return st->int_ref_uv;
1455 	default:
1456 		return -EINVAL;
1457 	}
1458 }
1459 
ad4130_parse_fw_setup(struct ad4130_state * st,struct fwnode_handle * child,struct ad4130_setup_info * setup_info)1460 static int ad4130_parse_fw_setup(struct ad4130_state *st,
1461 				 struct fwnode_handle *child,
1462 				 struct ad4130_setup_info *setup_info)
1463 {
1464 	struct device *dev = &st->spi->dev;
1465 	u32 tmp;
1466 	int ret;
1467 
1468 	tmp = 0;
1469 	fwnode_property_read_u32(child, "adi,excitation-current-0-nanoamp", &tmp);
1470 	ret = ad4130_find_table_index(ad4130_iout_current_na_tbl, tmp);
1471 	if (ret < 0)
1472 		return dev_err_probe(dev, ret,
1473 				     "Invalid excitation current %unA\n", tmp);
1474 	setup_info->iout0_val = ret;
1475 
1476 	tmp = 0;
1477 	fwnode_property_read_u32(child, "adi,excitation-current-1-nanoamp", &tmp);
1478 	ret = ad4130_find_table_index(ad4130_iout_current_na_tbl, tmp);
1479 	if (ret < 0)
1480 		return dev_err_probe(dev, ret,
1481 				     "Invalid excitation current %unA\n", tmp);
1482 	setup_info->iout1_val = ret;
1483 
1484 	tmp = 0;
1485 	fwnode_property_read_u32(child, "adi,burnout-current-nanoamp", &tmp);
1486 	ret = ad4130_find_table_index(ad4130_burnout_current_na_tbl, tmp);
1487 	if (ret < 0)
1488 		return dev_err_probe(dev, ret,
1489 				     "Invalid burnout current %unA\n", tmp);
1490 	setup_info->burnout = ret;
1491 
1492 	setup_info->ref_bufp = fwnode_property_read_bool(child, "adi,buffered-positive");
1493 	setup_info->ref_bufm = fwnode_property_read_bool(child, "adi,buffered-negative");
1494 
1495 	setup_info->ref_sel = AD4130_REF_REFIN1;
1496 	fwnode_property_read_u32(child, "adi,reference-select",
1497 				 &setup_info->ref_sel);
1498 	if (setup_info->ref_sel >= AD4130_REF_SEL_MAX)
1499 		return dev_err_probe(dev, -EINVAL,
1500 				     "Invalid reference selected %u\n",
1501 				     setup_info->ref_sel);
1502 
1503 	if (setup_info->ref_sel == AD4130_REF_REFOUT_AVSS)
1504 		st->int_ref_en = true;
1505 
1506 	ret = ad4130_get_ref_voltage(st, setup_info->ref_sel);
1507 	if (ret < 0)
1508 		return dev_err_probe(dev, ret, "Cannot use reference %u\n",
1509 				     setup_info->ref_sel);
1510 
1511 	return 0;
1512 }
1513 
ad4130_validate_diff_channel(struct ad4130_state * st,u32 pin)1514 static int ad4130_validate_diff_channel(struct ad4130_state *st, u32 pin)
1515 {
1516 	struct device *dev = &st->spi->dev;
1517 
1518 	if (pin >= AD4130_MAX_DIFF_INPUTS)
1519 		return dev_err_probe(dev, -EINVAL,
1520 				     "Invalid differential channel %u\n", pin);
1521 
1522 	if (pin >= AD4130_MAX_ANALOG_PINS)
1523 		return 0;
1524 
1525 	if (st->pins_fn[pin] == AD4130_PIN_FN_SPECIAL)
1526 		return dev_err_probe(dev, -EINVAL,
1527 				     "Pin %u already used with fn %u\n", pin,
1528 				     st->pins_fn[pin]);
1529 
1530 	st->pins_fn[pin] |= AD4130_PIN_FN_DIFF;
1531 
1532 	return 0;
1533 }
1534 
ad4130_validate_diff_channels(struct ad4130_state * st,u32 * pins,unsigned int len)1535 static int ad4130_validate_diff_channels(struct ad4130_state *st,
1536 					 u32 *pins, unsigned int len)
1537 {
1538 	unsigned int i;
1539 	int ret;
1540 
1541 	for (i = 0; i < len; i++) {
1542 		ret = ad4130_validate_diff_channel(st, pins[i]);
1543 		if (ret)
1544 			return ret;
1545 	}
1546 
1547 	return 0;
1548 }
1549 
ad4130_validate_excitation_pin(struct ad4130_state * st,u32 pin)1550 static int ad4130_validate_excitation_pin(struct ad4130_state *st, u32 pin)
1551 {
1552 	struct device *dev = &st->spi->dev;
1553 
1554 	if (pin >= AD4130_MAX_ANALOG_PINS)
1555 		return dev_err_probe(dev, -EINVAL,
1556 				     "Invalid excitation pin %u\n", pin);
1557 
1558 	if (st->pins_fn[pin] == AD4130_PIN_FN_SPECIAL)
1559 		return dev_err_probe(dev, -EINVAL,
1560 				     "Pin %u already used with fn %u\n", pin,
1561 				     st->pins_fn[pin]);
1562 
1563 	st->pins_fn[pin] |= AD4130_PIN_FN_EXCITATION;
1564 
1565 	return 0;
1566 }
1567 
ad4130_validate_vbias_pin(struct ad4130_state * st,u32 pin)1568 static int ad4130_validate_vbias_pin(struct ad4130_state *st, u32 pin)
1569 {
1570 	struct device *dev = &st->spi->dev;
1571 
1572 	if (pin >= AD4130_MAX_ANALOG_PINS)
1573 		return dev_err_probe(dev, -EINVAL, "Invalid vbias pin %u\n",
1574 				     pin);
1575 
1576 	if (st->pins_fn[pin] == AD4130_PIN_FN_SPECIAL)
1577 		return dev_err_probe(dev, -EINVAL,
1578 				     "Pin %u already used with fn %u\n", pin,
1579 				     st->pins_fn[pin]);
1580 
1581 	st->pins_fn[pin] |= AD4130_PIN_FN_VBIAS;
1582 
1583 	return 0;
1584 }
1585 
ad4130_validate_vbias_pins(struct ad4130_state * st,u32 * pins,unsigned int len)1586 static int ad4130_validate_vbias_pins(struct ad4130_state *st,
1587 				      u32 *pins, unsigned int len)
1588 {
1589 	unsigned int i;
1590 	int ret;
1591 
1592 	for (i = 0; i < st->num_vbias_pins; i++) {
1593 		ret = ad4130_validate_vbias_pin(st, pins[i]);
1594 		if (ret)
1595 			return ret;
1596 	}
1597 
1598 	return 0;
1599 }
1600 
ad4130_parse_fw_channel(struct iio_dev * indio_dev,struct fwnode_handle * child)1601 static int ad4130_parse_fw_channel(struct iio_dev *indio_dev,
1602 				   struct fwnode_handle *child)
1603 {
1604 	struct ad4130_state *st = iio_priv(indio_dev);
1605 	unsigned int resolution = ad4130_resolution(st);
1606 	unsigned int index = indio_dev->num_channels++;
1607 	struct device *dev = &st->spi->dev;
1608 	struct ad4130_chan_info *chan_info;
1609 	struct iio_chan_spec *chan;
1610 	u32 pins[2];
1611 	int ret;
1612 
1613 	if (index >= AD4130_MAX_CHANNELS)
1614 		return dev_err_probe(dev, -EINVAL, "Too many channels\n");
1615 
1616 	chan = &st->chans[index];
1617 	chan_info = &st->chans_info[index];
1618 
1619 	*chan = ad4130_channel_template;
1620 	chan->scan_type.realbits = resolution;
1621 	chan->scan_type.storagebits = resolution;
1622 	chan->scan_index = index;
1623 
1624 	chan_info->slot = AD4130_INVALID_SLOT;
1625 	chan_info->setup.fs = AD4130_FILTER_SELECT_MIN;
1626 	chan_info->initialized = true;
1627 
1628 	ret = fwnode_property_read_u32_array(child, "diff-channels", pins,
1629 					     ARRAY_SIZE(pins));
1630 	if (ret)
1631 		return ret;
1632 
1633 	ret = ad4130_validate_diff_channels(st, pins, ARRAY_SIZE(pins));
1634 	if (ret)
1635 		return ret;
1636 
1637 	chan->channel = pins[0];
1638 	chan->channel2 = pins[1];
1639 
1640 	ret = ad4130_parse_fw_setup(st, child, &chan_info->setup);
1641 	if (ret)
1642 		return ret;
1643 
1644 	fwnode_property_read_u32(child, "adi,excitation-pin-0",
1645 				 &chan_info->iout0);
1646 	if (chan_info->setup.iout0_val != AD4130_IOUT_OFF) {
1647 		ret = ad4130_validate_excitation_pin(st, chan_info->iout0);
1648 		if (ret)
1649 			return ret;
1650 	}
1651 
1652 	fwnode_property_read_u32(child, "adi,excitation-pin-1",
1653 				 &chan_info->iout1);
1654 	if (chan_info->setup.iout1_val != AD4130_IOUT_OFF) {
1655 		ret = ad4130_validate_excitation_pin(st, chan_info->iout1);
1656 		if (ret)
1657 			return ret;
1658 	}
1659 
1660 	return 0;
1661 }
1662 
ad4130_parse_fw_children(struct iio_dev * indio_dev)1663 static int ad4130_parse_fw_children(struct iio_dev *indio_dev)
1664 {
1665 	struct ad4130_state *st = iio_priv(indio_dev);
1666 	struct device *dev = &st->spi->dev;
1667 	struct fwnode_handle *child;
1668 	int ret;
1669 
1670 	indio_dev->channels = st->chans;
1671 
1672 	device_for_each_child_node(dev, child) {
1673 		ret = ad4130_parse_fw_channel(indio_dev, child);
1674 		if (ret) {
1675 			fwnode_handle_put(child);
1676 			return ret;
1677 		}
1678 	}
1679 
1680 	return 0;
1681 }
1682 
ad4310_parse_fw(struct iio_dev * indio_dev)1683 static int ad4310_parse_fw(struct iio_dev *indio_dev)
1684 {
1685 	struct ad4130_state *st = iio_priv(indio_dev);
1686 	struct device *dev = &st->spi->dev;
1687 	u32 ext_clk_freq = AD4130_MCLK_FREQ_76_8KHZ;
1688 	unsigned int i;
1689 	int avdd_uv;
1690 	int irq;
1691 	int ret;
1692 
1693 	st->mclk = devm_clk_get_optional(dev, "mclk");
1694 	if (IS_ERR(st->mclk))
1695 		return dev_err_probe(dev, PTR_ERR(st->mclk),
1696 				     "Failed to get mclk\n");
1697 
1698 	st->int_pin_sel = AD4130_INT_PIN_INT;
1699 
1700 	for (i = 0; i < ARRAY_SIZE(ad4130_int_pin_names); i++) {
1701 		irq = fwnode_irq_get_byname(dev_fwnode(dev),
1702 					    ad4130_int_pin_names[i]);
1703 		if (irq > 0) {
1704 			st->int_pin_sel = i;
1705 			break;
1706 		}
1707 	}
1708 
1709 	if (st->int_pin_sel == AD4130_INT_PIN_DOUT)
1710 		return dev_err_probe(dev, -EINVAL,
1711 				     "Cannot use DOUT as interrupt pin\n");
1712 
1713 	if (st->int_pin_sel == AD4130_INT_PIN_P2)
1714 		st->pins_fn[AD4130_AIN3_P2] = AD4130_PIN_FN_SPECIAL;
1715 
1716 	device_property_read_u32(dev, "adi,ext-clk-freq-hz", &ext_clk_freq);
1717 	if (ext_clk_freq != AD4130_MCLK_FREQ_153_6KHZ &&
1718 	    ext_clk_freq != AD4130_MCLK_FREQ_76_8KHZ)
1719 		return dev_err_probe(dev, -EINVAL,
1720 				     "Invalid external clock frequency %u\n",
1721 				     ext_clk_freq);
1722 
1723 	if (st->mclk && ext_clk_freq == AD4130_MCLK_FREQ_153_6KHZ)
1724 		st->mclk_sel = AD4130_MCLK_153_6KHZ_EXT;
1725 	else if (st->mclk)
1726 		st->mclk_sel = AD4130_MCLK_76_8KHZ_EXT;
1727 	else
1728 		st->mclk_sel = AD4130_MCLK_76_8KHZ;
1729 
1730 	if (st->int_pin_sel == AD4130_INT_PIN_CLK &&
1731 	    st->mclk_sel != AD4130_MCLK_76_8KHZ)
1732 		return dev_err_probe(dev, -EINVAL,
1733 				     "Invalid clock %u for interrupt pin %u\n",
1734 				     st->mclk_sel, st->int_pin_sel);
1735 
1736 	st->int_ref_uv = AD4130_INT_REF_2_5V;
1737 
1738 	/*
1739 	 * When the AVDD supply is set to below 2.5V the internal reference of
1740 	 * 1.25V should be selected.
1741 	 * See datasheet page 37, section ADC REFERENCE.
1742 	 */
1743 	avdd_uv = regulator_get_voltage(st->regulators[0].consumer);
1744 	if (avdd_uv > 0 && avdd_uv < AD4130_INT_REF_2_5V)
1745 		st->int_ref_uv = AD4130_INT_REF_1_25V;
1746 
1747 	st->bipolar = device_property_read_bool(dev, "adi,bipolar");
1748 
1749 	ret = device_property_count_u32(dev, "adi,vbias-pins");
1750 	if (ret > 0) {
1751 		if (ret > AD4130_MAX_ANALOG_PINS)
1752 			return dev_err_probe(dev, -EINVAL,
1753 					     "Too many vbias pins %u\n", ret);
1754 
1755 		st->num_vbias_pins = ret;
1756 
1757 		ret = device_property_read_u32_array(dev, "adi,vbias-pins",
1758 						     st->vbias_pins,
1759 						     st->num_vbias_pins);
1760 		if (ret)
1761 			return dev_err_probe(dev, ret,
1762 					     "Failed to read vbias pins\n");
1763 
1764 		ret = ad4130_validate_vbias_pins(st, st->vbias_pins,
1765 						 st->num_vbias_pins);
1766 		if (ret)
1767 			return ret;
1768 	}
1769 
1770 	ret = ad4130_parse_fw_children(indio_dev);
1771 	if (ret)
1772 		return ret;
1773 
1774 	return 0;
1775 }
1776 
ad4130_fill_scale_tbls(struct ad4130_state * st)1777 static void ad4130_fill_scale_tbls(struct ad4130_state *st)
1778 {
1779 	unsigned int pow = ad4130_resolution(st) - st->bipolar;
1780 	unsigned int i, j;
1781 
1782 	for (i = 0; i < AD4130_REF_SEL_MAX; i++) {
1783 		int ret;
1784 		u64 nv;
1785 
1786 		ret = ad4130_get_ref_voltage(st, i);
1787 		if (ret < 0)
1788 			continue;
1789 
1790 		nv = (u64)ret * NANO;
1791 
1792 		for (j = 0; j < AD4130_MAX_PGA; j++)
1793 			st->scale_tbls[i][j][1] = div_u64(nv >> (pow + j), MILLI);
1794 	}
1795 }
1796 
ad4130_clk_disable_unprepare(void * clk)1797 static void ad4130_clk_disable_unprepare(void *clk)
1798 {
1799 	clk_disable_unprepare(clk);
1800 }
1801 
ad4130_set_mclk_sel(struct ad4130_state * st,enum ad4130_mclk_sel mclk_sel)1802 static int ad4130_set_mclk_sel(struct ad4130_state *st,
1803 			       enum ad4130_mclk_sel mclk_sel)
1804 {
1805 	return regmap_update_bits(st->regmap, AD4130_ADC_CONTROL_REG,
1806 				 AD4130_ADC_CONTROL_MCLK_SEL_MASK,
1807 				 FIELD_PREP(AD4130_ADC_CONTROL_MCLK_SEL_MASK,
1808 					    mclk_sel));
1809 }
1810 
ad4130_int_clk_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)1811 static unsigned long ad4130_int_clk_recalc_rate(struct clk_hw *hw,
1812 						unsigned long parent_rate)
1813 {
1814 	return AD4130_MCLK_FREQ_76_8KHZ;
1815 }
1816 
ad4130_int_clk_is_enabled(struct clk_hw * hw)1817 static int ad4130_int_clk_is_enabled(struct clk_hw *hw)
1818 {
1819 	struct ad4130_state *st = container_of(hw, struct ad4130_state, int_clk_hw);
1820 
1821 	return st->mclk_sel == AD4130_MCLK_76_8KHZ_OUT;
1822 }
1823 
ad4130_int_clk_prepare(struct clk_hw * hw)1824 static int ad4130_int_clk_prepare(struct clk_hw *hw)
1825 {
1826 	struct ad4130_state *st = container_of(hw, struct ad4130_state, int_clk_hw);
1827 	int ret;
1828 
1829 	ret = ad4130_set_mclk_sel(st, AD4130_MCLK_76_8KHZ_OUT);
1830 	if (ret)
1831 		return ret;
1832 
1833 	st->mclk_sel = AD4130_MCLK_76_8KHZ_OUT;
1834 
1835 	return 0;
1836 }
1837 
ad4130_int_clk_unprepare(struct clk_hw * hw)1838 static void ad4130_int_clk_unprepare(struct clk_hw *hw)
1839 {
1840 	struct ad4130_state *st = container_of(hw, struct ad4130_state, int_clk_hw);
1841 	int ret;
1842 
1843 	ret = ad4130_set_mclk_sel(st, AD4130_MCLK_76_8KHZ);
1844 	if (ret)
1845 		return;
1846 
1847 	st->mclk_sel = AD4130_MCLK_76_8KHZ;
1848 }
1849 
1850 static const struct clk_ops ad4130_int_clk_ops = {
1851 	.recalc_rate = ad4130_int_clk_recalc_rate,
1852 	.is_enabled = ad4130_int_clk_is_enabled,
1853 	.prepare = ad4130_int_clk_prepare,
1854 	.unprepare = ad4130_int_clk_unprepare,
1855 };
1856 
ad4130_clk_del_provider(void * of_node)1857 static void ad4130_clk_del_provider(void *of_node)
1858 {
1859 	of_clk_del_provider(of_node);
1860 }
1861 
ad4130_setup_int_clk(struct ad4130_state * st)1862 static int ad4130_setup_int_clk(struct ad4130_state *st)
1863 {
1864 	struct device *dev = &st->spi->dev;
1865 	struct device_node *of_node = dev_of_node(dev);
1866 	struct clk_init_data init = {};
1867 	const char *clk_name;
1868 	struct clk *clk;
1869 	int ret;
1870 
1871 	if (st->int_pin_sel == AD4130_INT_PIN_CLK ||
1872 	    st->mclk_sel != AD4130_MCLK_76_8KHZ)
1873 		return 0;
1874 
1875 	if (!of_node)
1876 		return 0;
1877 
1878 	clk_name = of_node->name;
1879 	of_property_read_string(of_node, "clock-output-names", &clk_name);
1880 
1881 	init.name = clk_name;
1882 	init.ops = &ad4130_int_clk_ops;
1883 
1884 	st->int_clk_hw.init = &init;
1885 	clk = devm_clk_register(dev, &st->int_clk_hw);
1886 	if (IS_ERR(clk))
1887 		return PTR_ERR(clk);
1888 
1889 	ret = of_clk_add_provider(of_node, of_clk_src_simple_get, clk);
1890 	if (ret)
1891 		return ret;
1892 
1893 	return devm_add_action_or_reset(dev, ad4130_clk_del_provider, of_node);
1894 }
1895 
ad4130_setup(struct iio_dev * indio_dev)1896 static int ad4130_setup(struct iio_dev *indio_dev)
1897 {
1898 	struct ad4130_state *st = iio_priv(indio_dev);
1899 	struct device *dev = &st->spi->dev;
1900 	unsigned int int_ref_val;
1901 	unsigned long rate = AD4130_MCLK_FREQ_76_8KHZ;
1902 	unsigned int val;
1903 	unsigned int i;
1904 	int ret;
1905 
1906 	if (st->mclk_sel == AD4130_MCLK_153_6KHZ_EXT)
1907 		rate = AD4130_MCLK_FREQ_153_6KHZ;
1908 
1909 	ret = clk_set_rate(st->mclk, rate);
1910 	if (ret)
1911 		return ret;
1912 
1913 	ret = clk_prepare_enable(st->mclk);
1914 	if (ret)
1915 		return ret;
1916 
1917 	ret = devm_add_action_or_reset(dev, ad4130_clk_disable_unprepare,
1918 				       st->mclk);
1919 	if (ret)
1920 		return ret;
1921 
1922 	if (st->int_ref_uv == AD4130_INT_REF_2_5V)
1923 		int_ref_val = AD4130_INT_REF_VAL_2_5V;
1924 	else
1925 		int_ref_val = AD4130_INT_REF_VAL_1_25V;
1926 
1927 	/* Switch to SPI 4-wire mode. */
1928 	val =  FIELD_PREP(AD4130_ADC_CONTROL_CSB_EN_MASK, 1);
1929 	val |= FIELD_PREP(AD4130_ADC_CONTROL_BIPOLAR_MASK, st->bipolar);
1930 	val |= FIELD_PREP(AD4130_ADC_CONTROL_INT_REF_EN_MASK, st->int_ref_en);
1931 	val |= FIELD_PREP(AD4130_ADC_CONTROL_MODE_MASK, AD4130_MODE_IDLE);
1932 	val |= FIELD_PREP(AD4130_ADC_CONTROL_MCLK_SEL_MASK, st->mclk_sel);
1933 	val |= FIELD_PREP(AD4130_ADC_CONTROL_INT_REF_VAL_MASK, int_ref_val);
1934 
1935 	ret = regmap_write(st->regmap, AD4130_ADC_CONTROL_REG, val);
1936 	if (ret)
1937 		return ret;
1938 
1939 	/*
1940 	 * Configure unused GPIOs for output. If configured, the interrupt
1941 	 * function of P2 takes priority over the GPIO out function.
1942 	 */
1943 	val = 0;
1944 	for (i = 0; i < AD4130_MAX_GPIOS; i++)
1945 		if (st->pins_fn[i + AD4130_AIN2_P1] == AD4130_PIN_FN_NONE)
1946 			val |= FIELD_PREP(AD4130_IO_CONTROL_GPIO_CTRL_MASK, BIT(i));
1947 
1948 	val |= FIELD_PREP(AD4130_IO_CONTROL_INT_PIN_SEL_MASK, st->int_pin_sel);
1949 
1950 	ret = regmap_write(st->regmap, AD4130_IO_CONTROL_REG, val);
1951 	if (ret)
1952 		return ret;
1953 
1954 	val = 0;
1955 	for (i = 0; i < st->num_vbias_pins; i++)
1956 		val |= BIT(st->vbias_pins[i]);
1957 
1958 	ret = regmap_write(st->regmap, AD4130_VBIAS_REG, val);
1959 	if (ret)
1960 		return ret;
1961 
1962 	ret = regmap_update_bits(st->regmap, AD4130_FIFO_CONTROL_REG,
1963 				 AD4130_FIFO_CONTROL_HEADER_MASK, 0);
1964 	if (ret)
1965 		return ret;
1966 
1967 	/* FIFO watermark interrupt starts out as enabled, disable it. */
1968 	ret = ad4130_set_watermark_interrupt_en(st, false);
1969 	if (ret)
1970 		return ret;
1971 
1972 	/* Setup channels. */
1973 	for (i = 0; i < indio_dev->num_channels; i++) {
1974 		struct ad4130_chan_info *chan_info = &st->chans_info[i];
1975 		struct iio_chan_spec *chan = &st->chans[i];
1976 		unsigned int val;
1977 
1978 		val = FIELD_PREP(AD4130_CHANNEL_AINP_MASK, chan->channel) |
1979 		      FIELD_PREP(AD4130_CHANNEL_AINM_MASK, chan->channel2) |
1980 		      FIELD_PREP(AD4130_CHANNEL_IOUT1_MASK, chan_info->iout0) |
1981 		      FIELD_PREP(AD4130_CHANNEL_IOUT2_MASK, chan_info->iout1);
1982 
1983 		ret = regmap_write(st->regmap, AD4130_CHANNEL_X_REG(i), val);
1984 		if (ret)
1985 			return ret;
1986 	}
1987 
1988 	return 0;
1989 }
1990 
ad4130_soft_reset(struct ad4130_state * st)1991 static int ad4130_soft_reset(struct ad4130_state *st)
1992 {
1993 	int ret;
1994 
1995 	ret = spi_write(st->spi, st->reset_buf, sizeof(st->reset_buf));
1996 	if (ret)
1997 		return ret;
1998 
1999 	fsleep(AD4130_RESET_SLEEP_US);
2000 
2001 	return 0;
2002 }
2003 
ad4130_disable_regulators(void * data)2004 static void ad4130_disable_regulators(void *data)
2005 {
2006 	struct ad4130_state *st = data;
2007 
2008 	regulator_bulk_disable(ARRAY_SIZE(st->regulators), st->regulators);
2009 }
2010 
ad4130_probe(struct spi_device * spi)2011 static int ad4130_probe(struct spi_device *spi)
2012 {
2013 	struct device *dev = &spi->dev;
2014 	struct iio_dev *indio_dev;
2015 	struct ad4130_state *st;
2016 	int ret;
2017 
2018 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
2019 	if (!indio_dev)
2020 		return -ENOMEM;
2021 
2022 	st = iio_priv(indio_dev);
2023 
2024 	memset(st->reset_buf, 0xff, sizeof(st->reset_buf));
2025 	init_completion(&st->completion);
2026 	mutex_init(&st->lock);
2027 	st->spi = spi;
2028 
2029 	/*
2030 	 * Xfer:   [ XFR1 ] [         XFR2         ]
2031 	 * Master:  0x7D N   ......................
2032 	 * Slave:   ......   DATA1 DATA2 ... DATAN
2033 	 */
2034 	st->fifo_tx_buf[0] = AD4130_COMMS_READ_MASK | AD4130_FIFO_DATA_REG;
2035 	st->fifo_xfer[0].tx_buf = st->fifo_tx_buf;
2036 	st->fifo_xfer[0].len = sizeof(st->fifo_tx_buf);
2037 	st->fifo_xfer[1].rx_buf = st->fifo_rx_buf;
2038 	spi_message_init_with_transfers(&st->fifo_msg, st->fifo_xfer,
2039 					ARRAY_SIZE(st->fifo_xfer));
2040 
2041 	indio_dev->name = AD4130_NAME;
2042 	indio_dev->modes = INDIO_DIRECT_MODE;
2043 	indio_dev->info = &ad4130_info;
2044 
2045 	st->regmap = devm_regmap_init(dev, NULL, st, &ad4130_regmap_config);
2046 	if (IS_ERR(st->regmap))
2047 		return PTR_ERR(st->regmap);
2048 
2049 	st->regulators[0].supply = "avdd";
2050 	st->regulators[1].supply = "iovdd";
2051 	st->regulators[2].supply = "refin1";
2052 	st->regulators[3].supply = "refin2";
2053 
2054 	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(st->regulators),
2055 				      st->regulators);
2056 	if (ret)
2057 		return dev_err_probe(dev, ret, "Failed to get regulators\n");
2058 
2059 	ret = regulator_bulk_enable(ARRAY_SIZE(st->regulators), st->regulators);
2060 	if (ret)
2061 		return dev_err_probe(dev, ret, "Failed to enable regulators\n");
2062 
2063 	ret = devm_add_action_or_reset(dev, ad4130_disable_regulators, st);
2064 	if (ret)
2065 		return dev_err_probe(dev, ret,
2066 				     "Failed to add regulators disable action\n");
2067 
2068 	ret = ad4130_soft_reset(st);
2069 	if (ret)
2070 		return ret;
2071 
2072 	ret = ad4310_parse_fw(indio_dev);
2073 	if (ret)
2074 		return ret;
2075 
2076 	ret = ad4130_setup(indio_dev);
2077 	if (ret)
2078 		return ret;
2079 
2080 	ret = ad4130_setup_int_clk(st);
2081 	if (ret)
2082 		return ret;
2083 
2084 	ad4130_fill_scale_tbls(st);
2085 
2086 	st->gc.owner = THIS_MODULE;
2087 	st->gc.label = AD4130_NAME;
2088 	st->gc.base = -1;
2089 	st->gc.ngpio = AD4130_MAX_GPIOS;
2090 	st->gc.parent = dev;
2091 	st->gc.can_sleep = true;
2092 	st->gc.init_valid_mask = ad4130_gpio_init_valid_mask;
2093 	st->gc.get_direction = ad4130_gpio_get_direction;
2094 	st->gc.set = ad4130_gpio_set;
2095 
2096 	ret = devm_gpiochip_add_data(dev, &st->gc, st);
2097 	if (ret)
2098 		return ret;
2099 
2100 	ret = devm_iio_kfifo_buffer_setup_ext(dev, indio_dev,
2101 					      &ad4130_buffer_ops,
2102 					      ad4130_fifo_attributes);
2103 	if (ret)
2104 		return ret;
2105 
2106 	ret = devm_request_threaded_irq(dev, spi->irq, NULL,
2107 					ad4130_irq_handler, IRQF_ONESHOT,
2108 					indio_dev->name, indio_dev);
2109 	if (ret)
2110 		return dev_err_probe(dev, ret, "Failed to request irq\n");
2111 
2112 	/*
2113 	 * When the chip enters FIFO mode, IRQ polarity is inverted.
2114 	 * When the chip exits FIFO mode, IRQ polarity returns to normal.
2115 	 * See datasheet pages: 65, FIFO Watermark Interrupt section,
2116 	 * and 71, Bit Descriptions for STATUS Register, RDYB.
2117 	 * Cache the normal and inverted IRQ triggers to set them when
2118 	 * entering and exiting FIFO mode.
2119 	 */
2120 	st->irq_trigger = irq_get_trigger_type(spi->irq);
2121 	if (st->irq_trigger & IRQF_TRIGGER_RISING)
2122 		st->inv_irq_trigger = IRQF_TRIGGER_FALLING;
2123 	else if (st->irq_trigger & IRQF_TRIGGER_FALLING)
2124 		st->inv_irq_trigger = IRQF_TRIGGER_RISING;
2125 	else
2126 		return dev_err_probe(dev, -EINVAL, "Invalid irq flags: %u\n",
2127 				     st->irq_trigger);
2128 
2129 	return devm_iio_device_register(dev, indio_dev);
2130 }
2131 
2132 static const struct of_device_id ad4130_of_match[] = {
2133 	{
2134 		.compatible = "adi,ad4130",
2135 	},
2136 	{ }
2137 };
2138 MODULE_DEVICE_TABLE(of, ad4130_of_match);
2139 
2140 static struct spi_driver ad4130_driver = {
2141 	.driver = {
2142 		.name = AD4130_NAME,
2143 		.of_match_table = ad4130_of_match,
2144 	},
2145 	.probe = ad4130_probe,
2146 };
2147 module_spi_driver(ad4130_driver);
2148 
2149 MODULE_AUTHOR("Cosmin Tanislav <cosmin.tanislav@analog.com>");
2150 MODULE_DESCRIPTION("Analog Devices AD4130 SPI driver");
2151 MODULE_LICENSE("GPL");
2152