xref: /linux/drivers/iio/adc/ad7280a.c (revision 3a39d672e7f48b8d6b91a09afa4b55352773b4b5)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * AD7280A Lithium Ion Battery Monitoring System
4  *
5  * Copyright 2011 Analog Devices Inc.
6  */
7 
8 #include <linux/bitfield.h>
9 #include <linux/bits.h>
10 #include <linux/cleanup.h>
11 #include <linux/crc8.h>
12 #include <linux/delay.h>
13 #include <linux/device.h>
14 #include <linux/err.h>
15 #include <linux/interrupt.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/mod_devicetable.h>
19 #include <linux/mutex.h>
20 #include <linux/slab.h>
21 #include <linux/sysfs.h>
22 #include <linux/spi/spi.h>
23 
24 #include <linux/iio/events.h>
25 #include <linux/iio/iio.h>
26 
27 /* Registers */
28 
29 #define AD7280A_CELL_VOLTAGE_1_REG		0x0  /* D11 to D0, Read only */
30 #define AD7280A_CELL_VOLTAGE_2_REG		0x1  /* D11 to D0, Read only */
31 #define AD7280A_CELL_VOLTAGE_3_REG		0x2  /* D11 to D0, Read only */
32 #define AD7280A_CELL_VOLTAGE_4_REG		0x3  /* D11 to D0, Read only */
33 #define AD7280A_CELL_VOLTAGE_5_REG		0x4  /* D11 to D0, Read only */
34 #define AD7280A_CELL_VOLTAGE_6_REG		0x5  /* D11 to D0, Read only */
35 #define AD7280A_AUX_ADC_1_REG			0x6  /* D11 to D0, Read only */
36 #define AD7280A_AUX_ADC_2_REG			0x7  /* D11 to D0, Read only */
37 #define AD7280A_AUX_ADC_3_REG			0x8  /* D11 to D0, Read only */
38 #define AD7280A_AUX_ADC_4_REG			0x9  /* D11 to D0, Read only */
39 #define AD7280A_AUX_ADC_5_REG			0xA  /* D11 to D0, Read only */
40 #define AD7280A_AUX_ADC_6_REG			0xB  /* D11 to D0, Read only */
41 #define AD7280A_SELF_TEST_REG			0xC  /* D11 to D0, Read only */
42 
43 #define AD7280A_CTRL_HB_REG			0xD  /* D15 to D8, Read/write */
44 #define   AD7280A_CTRL_HB_CONV_INPUT_MSK		GENMASK(7, 6)
45 #define     AD7280A_CTRL_HB_CONV_INPUT_ALL			0
46 #define     AD7280A_CTRL_HB_CONV_INPUT_6CELL_AUX1_3_5		1
47 #define     AD7280A_CTRL_HB_CONV_INPUT_6CELL			2
48 #define     AD7280A_CTRL_HB_CONV_INPUT_SELF_TEST		3
49 #define   AD7280A_CTRL_HB_CONV_RREAD_MSK		GENMASK(5, 4)
50 #define     AD7280A_CTRL_HB_CONV_RREAD_ALL			0
51 #define     AD7280A_CTRL_HB_CONV_RREAD_6CELL_AUX1_3_5		1
52 #define     AD7280A_CTRL_HB_CONV_RREAD_6CELL			2
53 #define     AD7280A_CTRL_HB_CONV_RREAD_NO		        3
54 #define   AD7280A_CTRL_HB_CONV_START_MSK		BIT(3)
55 #define     AD7280A_CTRL_HB_CONV_START_CNVST			0
56 #define     AD7280A_CTRL_HB_CONV_START_CS			1
57 #define   AD7280A_CTRL_HB_CONV_AVG_MSK			GENMASK(2, 1)
58 #define     AD7280A_CTRL_HB_CONV_AVG_DIS			0
59 #define     AD7280A_CTRL_HB_CONV_AVG_2				1
60 #define     AD7280A_CTRL_HB_CONV_AVG_4			        2
61 #define     AD7280A_CTRL_HB_CONV_AVG_8			        3
62 #define   AD7280A_CTRL_HB_PWRDN_SW			BIT(0)
63 
64 #define AD7280A_CTRL_LB_REG			0xE  /* D7 to D0, Read/write */
65 #define   AD7280A_CTRL_LB_SWRST_MSK			BIT(7)
66 #define   AD7280A_CTRL_LB_ACQ_TIME_MSK			GENMASK(6, 5)
67 #define     AD7280A_CTRL_LB_ACQ_TIME_400ns			0
68 #define     AD7280A_CTRL_LB_ACQ_TIME_800ns			1
69 #define     AD7280A_CTRL_LB_ACQ_TIME_1200ns			2
70 #define     AD7280A_CTRL_LB_ACQ_TIME_1600ns			3
71 #define   AD7280A_CTRL_LB_MUST_SET			BIT(4)
72 #define   AD7280A_CTRL_LB_THERMISTOR_MSK		BIT(3)
73 #define   AD7280A_CTRL_LB_LOCK_DEV_ADDR_MSK		BIT(2)
74 #define   AD7280A_CTRL_LB_INC_DEV_ADDR_MSK		BIT(1)
75 #define   AD7280A_CTRL_LB_DAISY_CHAIN_RB_MSK		BIT(0)
76 
77 #define AD7280A_CELL_OVERVOLTAGE_REG		0xF  /* D7 to D0, Read/write */
78 #define AD7280A_CELL_UNDERVOLTAGE_REG		0x10 /* D7 to D0, Read/write */
79 #define AD7280A_AUX_ADC_OVERVOLTAGE_REG		0x11 /* D7 to D0, Read/write */
80 #define AD7280A_AUX_ADC_UNDERVOLTAGE_REG	0x12 /* D7 to D0, Read/write */
81 
82 #define AD7280A_ALERT_REG			0x13 /* D7 to D0, Read/write */
83 #define   AD7280A_ALERT_REMOVE_MSK			GENMASK(3, 0)
84 #define     AD7280A_ALERT_REMOVE_AUX5			BIT(0)
85 #define     AD7280A_ALERT_REMOVE_AUX3_AUX5		BIT(1)
86 #define     AD7280A_ALERT_REMOVE_VIN5			BIT(2)
87 #define     AD7280A_ALERT_REMOVE_VIN4_VIN5		BIT(3)
88 #define   AD7280A_ALERT_GEN_STATIC_HIGH			BIT(6)
89 #define   AD7280A_ALERT_RELAY_SIG_CHAIN_DOWN		(BIT(7) | BIT(6))
90 
91 #define AD7280A_CELL_BALANCE_REG		0x14 /* D7 to D0, Read/write */
92 #define  AD7280A_CELL_BALANCE_CHAN_BITMAP_MSK		GENMASK(7, 2)
93 #define AD7280A_CB1_TIMER_REG			0x15 /* D7 to D0, Read/write */
94 #define  AD7280A_CB_TIMER_VAL_MSK			GENMASK(7, 3)
95 #define AD7280A_CB2_TIMER_REG			0x16 /* D7 to D0, Read/write */
96 #define AD7280A_CB3_TIMER_REG			0x17 /* D7 to D0, Read/write */
97 #define AD7280A_CB4_TIMER_REG			0x18 /* D7 to D0, Read/write */
98 #define AD7280A_CB5_TIMER_REG			0x19 /* D7 to D0, Read/write */
99 #define AD7280A_CB6_TIMER_REG			0x1A /* D7 to D0, Read/write */
100 #define AD7280A_PD_TIMER_REG			0x1B /* D7 to D0, Read/write */
101 #define AD7280A_READ_REG			0x1C /* D7 to D0, Read/write */
102 #define   AD7280A_READ_ADDR_MSK				GENMASK(7, 2)
103 #define AD7280A_CNVST_CTRL_REG			0x1D /* D7 to D0, Read/write */
104 
105 /* Transfer fields */
106 #define AD7280A_TRANS_WRITE_DEVADDR_MSK		GENMASK(31, 27)
107 #define AD7280A_TRANS_WRITE_ADDR_MSK		GENMASK(26, 21)
108 #define AD7280A_TRANS_WRITE_VAL_MSK		GENMASK(20, 13)
109 #define AD7280A_TRANS_WRITE_ALL_MSK		BIT(12)
110 #define AD7280A_TRANS_WRITE_CRC_MSK		GENMASK(10, 3)
111 #define AD7280A_TRANS_WRITE_RES_PATTERN		0x2
112 
113 /* Layouts differ for channel vs other registers */
114 #define AD7280A_TRANS_READ_DEVADDR_MSK		GENMASK(31, 27)
115 #define AD7280A_TRANS_READ_CONV_CHANADDR_MSK	GENMASK(26, 23)
116 #define AD7280A_TRANS_READ_CONV_DATA_MSK	GENMASK(22, 11)
117 #define AD7280A_TRANS_READ_REG_REGADDR_MSK	GENMASK(26, 21)
118 #define AD7280A_TRANS_READ_REG_DATA_MSK		GENMASK(20, 13)
119 #define AD7280A_TRANS_READ_WRITE_ACK_MSK	BIT(10)
120 #define AD7280A_TRANS_READ_CRC_MSK		GENMASK(9, 2)
121 
122 /* Magic value used to indicate this special case */
123 #define AD7280A_ALL_CELLS				(0xAD << 16)
124 
125 #define AD7280A_MAX_SPI_CLK_HZ		700000 /* < 1MHz */
126 #define AD7280A_MAX_CHAIN		8
127 #define AD7280A_CELLS_PER_DEV		6
128 #define AD7280A_BITS			12
129 #define AD7280A_NUM_CH			(AD7280A_AUX_ADC_6_REG - \
130 					AD7280A_CELL_VOLTAGE_1_REG + 1)
131 
132 #define AD7280A_CALC_VOLTAGE_CHAN_NUM(d, c) (((d) * AD7280A_CELLS_PER_DEV) + \
133 					     (c))
134 #define AD7280A_CALC_TEMP_CHAN_NUM(d, c)    (((d) * AD7280A_CELLS_PER_DEV) + \
135 					     (c) - AD7280A_CELLS_PER_DEV)
136 
137 #define AD7280A_DEVADDR_MASTER		0
138 #define AD7280A_DEVADDR_ALL		0x1F
139 
140 static const unsigned short ad7280a_n_avg[4] = {1, 2, 4, 8};
141 static const unsigned short ad7280a_t_acq_ns[4] = {470, 1030, 1510, 1945};
142 
143 /* 5-bit device address is sent LSB first */
ad7280a_devaddr(unsigned int addr)144 static unsigned int ad7280a_devaddr(unsigned int addr)
145 {
146 	return ((addr & 0x1) << 4) |
147 	       ((addr & 0x2) << 2) |
148 	       (addr & 0x4) |
149 	       ((addr & 0x8) >> 2) |
150 	       ((addr & 0x10) >> 4);
151 }
152 
153 /*
154  * During a read a valid write is mandatory.
155  * So writing to the highest available address (Address 0x1F) and setting the
156  * address all parts bit to 0 is recommended.
157  * So the TXVAL is AD7280A_DEVADDR_ALL + CRC
158  */
159 #define AD7280A_READ_TXVAL	0xF800030A
160 
161 /*
162  * AD7280 CRC
163  *
164  * P(x) = x^8 + x^5 + x^3 + x^2 + x^1 + x^0 = 0b100101111 => 0x2F
165  */
166 #define POLYNOM		0x2F
167 
168 struct ad7280_state {
169 	struct spi_device		*spi;
170 	struct iio_chan_spec		*channels;
171 	unsigned int			chain_last_alert_ignore;
172 	bool				thermistor_term_en;
173 	int				slave_num;
174 	int				scan_cnt;
175 	int				readback_delay_us;
176 	unsigned char			crc_tab[CRC8_TABLE_SIZE];
177 	u8				oversampling_ratio;
178 	u8				acquisition_time;
179 	unsigned char			ctrl_lb;
180 	unsigned char			cell_threshhigh;
181 	unsigned char			cell_threshlow;
182 	unsigned char			aux_threshhigh;
183 	unsigned char			aux_threshlow;
184 	unsigned char			cb_mask[AD7280A_MAX_CHAIN];
185 	struct mutex			lock; /* protect sensor state */
186 
187 	__be32				tx __aligned(IIO_DMA_MINALIGN);
188 	__be32				rx;
189 };
190 
ad7280_calc_crc8(unsigned char * crc_tab,unsigned int val)191 static unsigned char ad7280_calc_crc8(unsigned char *crc_tab, unsigned int val)
192 {
193 	unsigned char crc;
194 
195 	crc = crc_tab[val >> 16 & 0xFF];
196 	crc = crc_tab[crc ^ (val >> 8 & 0xFF)];
197 
198 	return crc ^ (val & 0xFF);
199 }
200 
ad7280_check_crc(struct ad7280_state * st,unsigned int val)201 static int ad7280_check_crc(struct ad7280_state *st, unsigned int val)
202 {
203 	unsigned char crc = ad7280_calc_crc8(st->crc_tab, val >> 10);
204 
205 	if (crc != ((val >> 2) & 0xFF))
206 		return -EIO;
207 
208 	return 0;
209 }
210 
211 /*
212  * After initiating a conversion sequence we need to wait until the conversion
213  * is done. The delay is typically in the range of 15..30us however depending on
214  * the number of devices in the daisy chain, the number of averages taken,
215  * conversion delays and acquisition time options it may take up to 250us, in
216  * this case we better sleep instead of busy wait.
217  */
218 
ad7280_delay(struct ad7280_state * st)219 static void ad7280_delay(struct ad7280_state *st)
220 {
221 	if (st->readback_delay_us < 50)
222 		udelay(st->readback_delay_us);
223 	else
224 		usleep_range(250, 500);
225 }
226 
__ad7280_read32(struct ad7280_state * st,unsigned int * val)227 static int __ad7280_read32(struct ad7280_state *st, unsigned int *val)
228 {
229 	int ret;
230 	struct spi_transfer t = {
231 		.tx_buf	= &st->tx,
232 		.rx_buf = &st->rx,
233 		.len = sizeof(st->tx),
234 	};
235 
236 	st->tx = cpu_to_be32(AD7280A_READ_TXVAL);
237 
238 	ret = spi_sync_transfer(st->spi, &t, 1);
239 	if (ret)
240 		return ret;
241 
242 	*val = be32_to_cpu(st->rx);
243 
244 	return 0;
245 }
246 
ad7280_write(struct ad7280_state * st,unsigned int devaddr,unsigned int addr,bool all,unsigned int val)247 static int ad7280_write(struct ad7280_state *st, unsigned int devaddr,
248 			unsigned int addr, bool all, unsigned int val)
249 {
250 	unsigned int reg = FIELD_PREP(AD7280A_TRANS_WRITE_DEVADDR_MSK, devaddr) |
251 		FIELD_PREP(AD7280A_TRANS_WRITE_ADDR_MSK, addr) |
252 		FIELD_PREP(AD7280A_TRANS_WRITE_VAL_MSK, val) |
253 		FIELD_PREP(AD7280A_TRANS_WRITE_ALL_MSK, all);
254 
255 	reg |= FIELD_PREP(AD7280A_TRANS_WRITE_CRC_MSK,
256 			ad7280_calc_crc8(st->crc_tab, reg >> 11));
257 	/* Reserved b010 pattern not included crc calc */
258 	reg |= AD7280A_TRANS_WRITE_RES_PATTERN;
259 
260 	st->tx = cpu_to_be32(reg);
261 
262 	return spi_write(st->spi, &st->tx, sizeof(st->tx));
263 }
264 
ad7280_read_reg(struct ad7280_state * st,unsigned int devaddr,unsigned int addr)265 static int ad7280_read_reg(struct ad7280_state *st, unsigned int devaddr,
266 			   unsigned int addr)
267 {
268 	int ret;
269 	unsigned int tmp;
270 
271 	/* turns off the read operation on all parts */
272 	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CTRL_HB_REG, 1,
273 			   FIELD_PREP(AD7280A_CTRL_HB_CONV_INPUT_MSK,
274 				      AD7280A_CTRL_HB_CONV_INPUT_ALL) |
275 			   FIELD_PREP(AD7280A_CTRL_HB_CONV_RREAD_MSK,
276 				      AD7280A_CTRL_HB_CONV_RREAD_NO) |
277 			   FIELD_PREP(AD7280A_CTRL_HB_CONV_AVG_MSK,
278 				      st->oversampling_ratio));
279 	if (ret)
280 		return ret;
281 
282 	/* turns on the read operation on the addressed part */
283 	ret = ad7280_write(st, devaddr, AD7280A_CTRL_HB_REG, 0,
284 			   FIELD_PREP(AD7280A_CTRL_HB_CONV_INPUT_MSK,
285 				      AD7280A_CTRL_HB_CONV_INPUT_ALL) |
286 			   FIELD_PREP(AD7280A_CTRL_HB_CONV_RREAD_MSK,
287 				      AD7280A_CTRL_HB_CONV_RREAD_ALL) |
288 			   FIELD_PREP(AD7280A_CTRL_HB_CONV_AVG_MSK,
289 				      st->oversampling_ratio));
290 	if (ret)
291 		return ret;
292 
293 	/* Set register address on the part to be read from */
294 	ret = ad7280_write(st, devaddr, AD7280A_READ_REG, 0,
295 			   FIELD_PREP(AD7280A_READ_ADDR_MSK, addr));
296 	if (ret)
297 		return ret;
298 
299 	ret = __ad7280_read32(st, &tmp);
300 	if (ret)
301 		return ret;
302 
303 	if (ad7280_check_crc(st, tmp))
304 		return -EIO;
305 
306 	if ((FIELD_GET(AD7280A_TRANS_READ_DEVADDR_MSK, tmp) != devaddr) ||
307 	    (FIELD_GET(AD7280A_TRANS_READ_REG_REGADDR_MSK, tmp) != addr))
308 		return -EFAULT;
309 
310 	return FIELD_GET(AD7280A_TRANS_READ_REG_DATA_MSK, tmp);
311 }
312 
ad7280_read_channel(struct ad7280_state * st,unsigned int devaddr,unsigned int addr)313 static int ad7280_read_channel(struct ad7280_state *st, unsigned int devaddr,
314 			       unsigned int addr)
315 {
316 	int ret;
317 	unsigned int tmp;
318 
319 	ret = ad7280_write(st, devaddr, AD7280A_READ_REG, 0,
320 			   FIELD_PREP(AD7280A_READ_ADDR_MSK, addr));
321 	if (ret)
322 		return ret;
323 
324 	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CTRL_HB_REG, 1,
325 			   FIELD_PREP(AD7280A_CTRL_HB_CONV_INPUT_MSK,
326 				      AD7280A_CTRL_HB_CONV_INPUT_ALL) |
327 			   FIELD_PREP(AD7280A_CTRL_HB_CONV_RREAD_MSK,
328 				      AD7280A_CTRL_HB_CONV_RREAD_NO) |
329 			   FIELD_PREP(AD7280A_CTRL_HB_CONV_AVG_MSK,
330 				      st->oversampling_ratio));
331 	if (ret)
332 		return ret;
333 
334 	ret = ad7280_write(st, devaddr, AD7280A_CTRL_HB_REG, 0,
335 			   FIELD_PREP(AD7280A_CTRL_HB_CONV_INPUT_MSK,
336 				      AD7280A_CTRL_HB_CONV_INPUT_ALL) |
337 			   FIELD_PREP(AD7280A_CTRL_HB_CONV_RREAD_MSK,
338 				      AD7280A_CTRL_HB_CONV_RREAD_ALL) |
339 			   FIELD_PREP(AD7280A_CTRL_HB_CONV_START_MSK,
340 				      AD7280A_CTRL_HB_CONV_START_CS) |
341 			   FIELD_PREP(AD7280A_CTRL_HB_CONV_AVG_MSK,
342 				      st->oversampling_ratio));
343 	if (ret)
344 		return ret;
345 
346 	ad7280_delay(st);
347 
348 	ret = __ad7280_read32(st, &tmp);
349 	if (ret)
350 		return ret;
351 
352 	if (ad7280_check_crc(st, tmp))
353 		return -EIO;
354 
355 	if ((FIELD_GET(AD7280A_TRANS_READ_DEVADDR_MSK, tmp) != devaddr) ||
356 	    (FIELD_GET(AD7280A_TRANS_READ_CONV_CHANADDR_MSK, tmp) != addr))
357 		return -EFAULT;
358 
359 	return FIELD_GET(AD7280A_TRANS_READ_CONV_DATA_MSK, tmp);
360 }
361 
ad7280_read_all_channels(struct ad7280_state * st,unsigned int cnt,unsigned int * array)362 static int ad7280_read_all_channels(struct ad7280_state *st, unsigned int cnt,
363 				    unsigned int *array)
364 {
365 	int i, ret;
366 	unsigned int tmp, sum = 0;
367 
368 	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_READ_REG, 1,
369 			   AD7280A_CELL_VOLTAGE_1_REG << 2);
370 	if (ret)
371 		return ret;
372 
373 	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CTRL_HB_REG, 1,
374 			   FIELD_PREP(AD7280A_CTRL_HB_CONV_INPUT_MSK,
375 				      AD7280A_CTRL_HB_CONV_INPUT_ALL) |
376 			   FIELD_PREP(AD7280A_CTRL_HB_CONV_RREAD_MSK,
377 				      AD7280A_CTRL_HB_CONV_RREAD_ALL) |
378 			   FIELD_PREP(AD7280A_CTRL_HB_CONV_START_MSK,
379 				      AD7280A_CTRL_HB_CONV_START_CS) |
380 			   FIELD_PREP(AD7280A_CTRL_HB_CONV_AVG_MSK,
381 				      st->oversampling_ratio));
382 	if (ret)
383 		return ret;
384 
385 	ad7280_delay(st);
386 
387 	for (i = 0; i < cnt; i++) {
388 		ret = __ad7280_read32(st, &tmp);
389 		if (ret)
390 			return ret;
391 
392 		if (ad7280_check_crc(st, tmp))
393 			return -EIO;
394 
395 		if (array)
396 			array[i] = tmp;
397 		/* only sum cell voltages */
398 		if (FIELD_GET(AD7280A_TRANS_READ_CONV_CHANADDR_MSK, tmp) <=
399 		    AD7280A_CELL_VOLTAGE_6_REG)
400 			sum += FIELD_GET(AD7280A_TRANS_READ_CONV_DATA_MSK, tmp);
401 	}
402 
403 	return sum;
404 }
405 
ad7280_sw_power_down(void * data)406 static void ad7280_sw_power_down(void *data)
407 {
408 	struct ad7280_state *st = data;
409 
410 	ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CTRL_HB_REG, 1,
411 		     AD7280A_CTRL_HB_PWRDN_SW |
412 		     FIELD_PREP(AD7280A_CTRL_HB_CONV_AVG_MSK, st->oversampling_ratio));
413 }
414 
ad7280_chain_setup(struct ad7280_state * st)415 static int ad7280_chain_setup(struct ad7280_state *st)
416 {
417 	unsigned int val, n;
418 	int ret;
419 
420 	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CTRL_LB_REG, 1,
421 			   FIELD_PREP(AD7280A_CTRL_LB_DAISY_CHAIN_RB_MSK, 1) |
422 			   FIELD_PREP(AD7280A_CTRL_LB_LOCK_DEV_ADDR_MSK, 1) |
423 			   AD7280A_CTRL_LB_MUST_SET |
424 			   FIELD_PREP(AD7280A_CTRL_LB_SWRST_MSK, 1) |
425 			   st->ctrl_lb);
426 	if (ret)
427 		return ret;
428 
429 	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CTRL_LB_REG, 1,
430 			   FIELD_PREP(AD7280A_CTRL_LB_DAISY_CHAIN_RB_MSK, 1) |
431 			   FIELD_PREP(AD7280A_CTRL_LB_LOCK_DEV_ADDR_MSK, 1) |
432 			   AD7280A_CTRL_LB_MUST_SET |
433 			   FIELD_PREP(AD7280A_CTRL_LB_SWRST_MSK, 0) |
434 			   st->ctrl_lb);
435 	if (ret)
436 		goto error_power_down;
437 
438 	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_READ_REG, 1,
439 			   FIELD_PREP(AD7280A_READ_ADDR_MSK, AD7280A_CTRL_LB_REG));
440 	if (ret)
441 		goto error_power_down;
442 
443 	for (n = 0; n <= AD7280A_MAX_CHAIN; n++) {
444 		ret = __ad7280_read32(st, &val);
445 		if (ret)
446 			goto error_power_down;
447 
448 		if (val == 0)
449 			return n - 1;
450 
451 		if (ad7280_check_crc(st, val)) {
452 			ret = -EIO;
453 			goto error_power_down;
454 		}
455 
456 		if (n != ad7280a_devaddr(FIELD_GET(AD7280A_TRANS_READ_DEVADDR_MSK, val))) {
457 			ret = -EIO;
458 			goto error_power_down;
459 		}
460 	}
461 	ret = -EFAULT;
462 
463 error_power_down:
464 	ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CTRL_HB_REG, 1,
465 		     AD7280A_CTRL_HB_PWRDN_SW |
466 		     FIELD_PREP(AD7280A_CTRL_HB_CONV_AVG_MSK, st->oversampling_ratio));
467 
468 	return ret;
469 }
470 
ad7280_show_balance_sw(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,char * buf)471 static ssize_t ad7280_show_balance_sw(struct iio_dev *indio_dev,
472 				      uintptr_t private,
473 				      const struct iio_chan_spec *chan, char *buf)
474 {
475 	struct ad7280_state *st = iio_priv(indio_dev);
476 
477 	return sysfs_emit(buf, "%d\n",
478 			  !!(st->cb_mask[chan->address >> 8] &
479 			     BIT(chan->address & 0xFF)));
480 }
481 
ad7280_store_balance_sw(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,const char * buf,size_t len)482 static ssize_t ad7280_store_balance_sw(struct iio_dev *indio_dev,
483 				       uintptr_t private,
484 				       const struct iio_chan_spec *chan,
485 				       const char *buf, size_t len)
486 {
487 	struct ad7280_state *st = iio_priv(indio_dev);
488 	unsigned int devaddr, ch;
489 	bool readin;
490 	int ret;
491 
492 	ret = kstrtobool(buf, &readin);
493 	if (ret)
494 		return ret;
495 
496 	devaddr = chan->address >> 8;
497 	ch = chan->address & 0xFF;
498 
499 	mutex_lock(&st->lock);
500 	if (readin)
501 		st->cb_mask[devaddr] |= BIT(ch);
502 	else
503 		st->cb_mask[devaddr] &= ~BIT(ch);
504 
505 	ret = ad7280_write(st, devaddr, AD7280A_CELL_BALANCE_REG, 0,
506 			   FIELD_PREP(AD7280A_CELL_BALANCE_CHAN_BITMAP_MSK,
507 				      st->cb_mask[devaddr]));
508 	mutex_unlock(&st->lock);
509 
510 	return ret ? ret : len;
511 }
512 
ad7280_show_balance_timer(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,char * buf)513 static ssize_t ad7280_show_balance_timer(struct iio_dev *indio_dev,
514 					 uintptr_t private,
515 					 const struct iio_chan_spec *chan,
516 					 char *buf)
517 {
518 	struct ad7280_state *st = iio_priv(indio_dev);
519 	unsigned int msecs;
520 	int ret;
521 
522 	mutex_lock(&st->lock);
523 	ret = ad7280_read_reg(st, chan->address >> 8,
524 			      (chan->address & 0xFF) + AD7280A_CB1_TIMER_REG);
525 	mutex_unlock(&st->lock);
526 
527 	if (ret < 0)
528 		return ret;
529 
530 	msecs = FIELD_GET(AD7280A_CB_TIMER_VAL_MSK, ret) * 71500;
531 
532 	return sysfs_emit(buf, "%u.%u\n", msecs / 1000, msecs % 1000);
533 }
534 
ad7280_store_balance_timer(struct iio_dev * indio_dev,uintptr_t private,const struct iio_chan_spec * chan,const char * buf,size_t len)535 static ssize_t ad7280_store_balance_timer(struct iio_dev *indio_dev,
536 					  uintptr_t private,
537 					  const struct iio_chan_spec *chan,
538 					  const char *buf, size_t len)
539 {
540 	struct ad7280_state *st = iio_priv(indio_dev);
541 	int val, val2;
542 	int ret;
543 
544 	ret = iio_str_to_fixpoint(buf, 1000, &val, &val2);
545 	if (ret)
546 		return ret;
547 
548 	val = val * 1000 + val2;
549 	val /= 71500;
550 
551 	if (val > 31)
552 		return -EINVAL;
553 
554 	mutex_lock(&st->lock);
555 	ret = ad7280_write(st, chan->address >> 8,
556 			   (chan->address & 0xFF) + AD7280A_CB1_TIMER_REG, 0,
557 			   FIELD_PREP(AD7280A_CB_TIMER_VAL_MSK, val));
558 	mutex_unlock(&st->lock);
559 
560 	return ret ? ret : len;
561 }
562 
563 static const struct iio_chan_spec_ext_info ad7280_cell_ext_info[] = {
564 	{
565 		.name = "balance_switch_en",
566 		.read = ad7280_show_balance_sw,
567 		.write = ad7280_store_balance_sw,
568 		.shared = IIO_SEPARATE,
569 	}, {
570 		.name = "balance_switch_timer",
571 		.read = ad7280_show_balance_timer,
572 		.write = ad7280_store_balance_timer,
573 		.shared = IIO_SEPARATE,
574 	},
575 	{}
576 };
577 
578 static const struct iio_event_spec ad7280_events[] = {
579 	{
580 		.type = IIO_EV_TYPE_THRESH,
581 		.dir = IIO_EV_DIR_RISING,
582 		.mask_shared_by_type = BIT(IIO_EV_INFO_VALUE),
583 	}, {
584 		.type = IIO_EV_TYPE_THRESH,
585 		.dir = IIO_EV_DIR_FALLING,
586 		.mask_shared_by_type = BIT(IIO_EV_INFO_VALUE),
587 	},
588 };
589 
ad7280_voltage_channel_init(struct iio_chan_spec * chan,int i,bool irq_present)590 static void ad7280_voltage_channel_init(struct iio_chan_spec *chan, int i,
591 					bool irq_present)
592 {
593 	chan->type = IIO_VOLTAGE;
594 	chan->differential = 1;
595 	chan->channel = i;
596 	chan->channel2 = chan->channel + 1;
597 	if (irq_present) {
598 		chan->event_spec = ad7280_events;
599 		chan->num_event_specs = ARRAY_SIZE(ad7280_events);
600 	}
601 	chan->ext_info = ad7280_cell_ext_info;
602 }
603 
ad7280_temp_channel_init(struct iio_chan_spec * chan,int i,bool irq_present)604 static void ad7280_temp_channel_init(struct iio_chan_spec *chan, int i,
605 				     bool irq_present)
606 {
607 	chan->type = IIO_TEMP;
608 	chan->channel = i;
609 	if (irq_present) {
610 		chan->event_spec = ad7280_events;
611 		chan->num_event_specs = ARRAY_SIZE(ad7280_events);
612 	}
613 }
614 
ad7280_common_fields_init(struct iio_chan_spec * chan,int addr,int cnt)615 static void ad7280_common_fields_init(struct iio_chan_spec *chan, int addr,
616 				      int cnt)
617 {
618 	chan->indexed = 1;
619 	chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
620 	chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
621 	chan->info_mask_shared_by_all = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO);
622 	chan->address = addr;
623 	chan->scan_index = cnt;
624 	chan->scan_type.sign = 'u';
625 	chan->scan_type.realbits = 12;
626 	chan->scan_type.storagebits = 32;
627 }
628 
ad7280_total_voltage_channel_init(struct iio_chan_spec * chan,int cnt,int dev)629 static void ad7280_total_voltage_channel_init(struct iio_chan_spec *chan,
630 					      int cnt, int dev)
631 {
632 	chan->type = IIO_VOLTAGE;
633 	chan->differential = 1;
634 	chan->channel = 0;
635 	chan->channel2 = dev * AD7280A_CELLS_PER_DEV;
636 	chan->address = AD7280A_ALL_CELLS;
637 	chan->indexed = 1;
638 	chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
639 	chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
640 	chan->scan_index = cnt;
641 	chan->scan_type.sign = 'u';
642 	chan->scan_type.realbits = 32;
643 	chan->scan_type.storagebits = 32;
644 }
645 
ad7280_init_dev_channels(struct ad7280_state * st,int dev,int * cnt,bool irq_present)646 static void ad7280_init_dev_channels(struct ad7280_state *st, int dev, int *cnt,
647 				     bool irq_present)
648 {
649 	int addr, ch, i;
650 	struct iio_chan_spec *chan;
651 
652 	for (ch = AD7280A_CELL_VOLTAGE_1_REG; ch <= AD7280A_AUX_ADC_6_REG; ch++) {
653 		chan = &st->channels[*cnt];
654 
655 		if (ch < AD7280A_AUX_ADC_1_REG) {
656 			i = AD7280A_CALC_VOLTAGE_CHAN_NUM(dev, ch);
657 			ad7280_voltage_channel_init(chan, i, irq_present);
658 		} else {
659 			i = AD7280A_CALC_TEMP_CHAN_NUM(dev, ch);
660 			ad7280_temp_channel_init(chan, i, irq_present);
661 		}
662 
663 		addr = ad7280a_devaddr(dev) << 8 | ch;
664 		ad7280_common_fields_init(chan, addr, *cnt);
665 
666 		(*cnt)++;
667 	}
668 }
669 
ad7280_channel_init(struct ad7280_state * st,bool irq_present)670 static int ad7280_channel_init(struct ad7280_state *st, bool irq_present)
671 {
672 	int dev, cnt = 0;
673 
674 	st->channels = devm_kcalloc(&st->spi->dev, (st->slave_num + 1) * 12 + 1,
675 				    sizeof(*st->channels), GFP_KERNEL);
676 	if (!st->channels)
677 		return -ENOMEM;
678 
679 	for (dev = 0; dev <= st->slave_num; dev++)
680 		ad7280_init_dev_channels(st, dev, &cnt, irq_present);
681 
682 	ad7280_total_voltage_channel_init(&st->channels[cnt], cnt, dev);
683 
684 	return cnt + 1;
685 }
686 
ad7280a_read_thresh(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,enum iio_event_type type,enum iio_event_direction dir,enum iio_event_info info,int * val,int * val2)687 static int ad7280a_read_thresh(struct iio_dev *indio_dev,
688 			       const struct iio_chan_spec *chan,
689 			       enum iio_event_type type,
690 			       enum iio_event_direction dir,
691 			       enum iio_event_info info, int *val, int *val2)
692 {
693 	struct ad7280_state *st = iio_priv(indio_dev);
694 
695 	switch (chan->type) {
696 	case IIO_VOLTAGE:
697 		switch (dir) {
698 		case IIO_EV_DIR_RISING:
699 			*val = 1000 + (st->cell_threshhigh * 1568L) / 100;
700 			return IIO_VAL_INT;
701 		case IIO_EV_DIR_FALLING:
702 			*val = 1000 + (st->cell_threshlow * 1568L) / 100;
703 			return IIO_VAL_INT;
704 		default:
705 			return -EINVAL;
706 		}
707 		break;
708 	case IIO_TEMP:
709 		switch (dir) {
710 		case IIO_EV_DIR_RISING:
711 			*val = ((st->aux_threshhigh) * 196L) / 10;
712 			return IIO_VAL_INT;
713 		case IIO_EV_DIR_FALLING:
714 			*val = (st->aux_threshlow * 196L) / 10;
715 			return IIO_VAL_INT;
716 		default:
717 			return -EINVAL;
718 		}
719 		break;
720 	default:
721 		return -EINVAL;
722 	}
723 }
724 
ad7280a_write_thresh(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,enum iio_event_type type,enum iio_event_direction dir,enum iio_event_info info,int val,int val2)725 static int ad7280a_write_thresh(struct iio_dev *indio_dev,
726 				const struct iio_chan_spec *chan,
727 				enum iio_event_type type,
728 				enum iio_event_direction dir,
729 				enum iio_event_info info,
730 				int val, int val2)
731 {
732 	struct ad7280_state *st = iio_priv(indio_dev);
733 	unsigned int addr;
734 	long value;
735 	int ret;
736 
737 	if (val2 != 0)
738 		return -EINVAL;
739 
740 	mutex_lock(&st->lock);
741 	switch (chan->type) {
742 	case IIO_VOLTAGE:
743 		value = ((val - 1000) * 100) / 1568; /* LSB 15.68mV */
744 		value = clamp(value, 0L, 0xFFL);
745 		switch (dir) {
746 		case IIO_EV_DIR_RISING:
747 			addr = AD7280A_CELL_OVERVOLTAGE_REG;
748 			ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, addr,
749 					   1, value);
750 			if (ret)
751 				break;
752 			st->cell_threshhigh = value;
753 			break;
754 		case IIO_EV_DIR_FALLING:
755 			addr = AD7280A_CELL_UNDERVOLTAGE_REG;
756 			ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, addr,
757 					   1, value);
758 			if (ret)
759 				break;
760 			st->cell_threshlow = value;
761 			break;
762 		default:
763 			ret = -EINVAL;
764 			goto err_unlock;
765 		}
766 		break;
767 	case IIO_TEMP:
768 		value = (val * 10) / 196; /* LSB 19.6mV */
769 		value = clamp(value, 0L, 0xFFL);
770 		switch (dir) {
771 		case IIO_EV_DIR_RISING:
772 			addr = AD7280A_AUX_ADC_OVERVOLTAGE_REG;
773 			ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, addr,
774 					   1, value);
775 			if (ret)
776 				break;
777 			st->aux_threshhigh = value;
778 			break;
779 		case IIO_EV_DIR_FALLING:
780 			addr = AD7280A_AUX_ADC_UNDERVOLTAGE_REG;
781 			ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, addr,
782 					   1, value);
783 			if (ret)
784 				break;
785 			st->aux_threshlow = value;
786 			break;
787 		default:
788 			ret = -EINVAL;
789 			goto err_unlock;
790 		}
791 		break;
792 	default:
793 		ret = -EINVAL;
794 		goto err_unlock;
795 	}
796 
797 err_unlock:
798 	mutex_unlock(&st->lock);
799 
800 	return ret;
801 }
802 
ad7280_event_handler(int irq,void * private)803 static irqreturn_t ad7280_event_handler(int irq, void *private)
804 {
805 	struct iio_dev *indio_dev = private;
806 	struct ad7280_state *st = iio_priv(indio_dev);
807 	int i, ret;
808 
809 	unsigned int *channels __free(kfree) = kcalloc(st->scan_cnt, sizeof(*channels),
810 						       GFP_KERNEL);
811 	if (!channels)
812 		return IRQ_HANDLED;
813 
814 	ret = ad7280_read_all_channels(st, st->scan_cnt, channels);
815 	if (ret < 0)
816 		return IRQ_HANDLED;
817 
818 	for (i = 0; i < st->scan_cnt; i++) {
819 		unsigned int val;
820 
821 		val = FIELD_GET(AD7280A_TRANS_READ_CONV_DATA_MSK, channels[i]);
822 		if (FIELD_GET(AD7280A_TRANS_READ_CONV_CHANADDR_MSK, channels[i]) <=
823 		    AD7280A_CELL_VOLTAGE_6_REG) {
824 			if (val >= st->cell_threshhigh) {
825 				u64 tmp = IIO_EVENT_CODE(IIO_VOLTAGE, 1, 0,
826 							 IIO_EV_DIR_RISING,
827 							 IIO_EV_TYPE_THRESH,
828 							 0, 0, 0);
829 				iio_push_event(indio_dev, tmp,
830 					       iio_get_time_ns(indio_dev));
831 			} else if (val <= st->cell_threshlow) {
832 				u64 tmp = IIO_EVENT_CODE(IIO_VOLTAGE, 1, 0,
833 							 IIO_EV_DIR_FALLING,
834 							 IIO_EV_TYPE_THRESH,
835 							 0, 0, 0);
836 				iio_push_event(indio_dev, tmp,
837 					       iio_get_time_ns(indio_dev));
838 			}
839 		} else {
840 			if (val >= st->aux_threshhigh) {
841 				u64 tmp = IIO_UNMOD_EVENT_CODE(IIO_TEMP, 0,
842 							IIO_EV_TYPE_THRESH,
843 							IIO_EV_DIR_RISING);
844 				iio_push_event(indio_dev, tmp,
845 					       iio_get_time_ns(indio_dev));
846 			} else if (val <= st->aux_threshlow) {
847 				u64 tmp = IIO_UNMOD_EVENT_CODE(IIO_TEMP, 0,
848 							IIO_EV_TYPE_THRESH,
849 							IIO_EV_DIR_FALLING);
850 				iio_push_event(indio_dev, tmp,
851 					       iio_get_time_ns(indio_dev));
852 			}
853 		}
854 	}
855 
856 	return IRQ_HANDLED;
857 }
858 
ad7280_update_delay(struct ad7280_state * st)859 static void ad7280_update_delay(struct ad7280_state *st)
860 {
861 	/*
862 	 * Total Conversion Time = ((tACQ + tCONV) *
863 	 *			   (Number of Conversions per Part)) −
864 	 *			   tACQ + ((N - 1) * tDELAY)
865 	 *
866 	 * Readback Delay = Total Conversion Time + tWAIT
867 	 */
868 
869 	st->readback_delay_us =
870 		((ad7280a_t_acq_ns[st->acquisition_time & 0x3] + 720) *
871 			(AD7280A_NUM_CH * ad7280a_n_avg[st->oversampling_ratio & 0x3])) -
872 		ad7280a_t_acq_ns[st->acquisition_time & 0x3] + st->slave_num * 250;
873 
874 	/* Convert to usecs */
875 	st->readback_delay_us = DIV_ROUND_UP(st->readback_delay_us, 1000);
876 	st->readback_delay_us += 5; /* Add tWAIT */
877 }
878 
ad7280_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long m)879 static int ad7280_read_raw(struct iio_dev *indio_dev,
880 			   struct iio_chan_spec const *chan,
881 			   int *val,
882 			   int *val2,
883 			   long m)
884 {
885 	struct ad7280_state *st = iio_priv(indio_dev);
886 	int ret;
887 
888 	switch (m) {
889 	case IIO_CHAN_INFO_RAW:
890 		mutex_lock(&st->lock);
891 		if (chan->address == AD7280A_ALL_CELLS)
892 			ret = ad7280_read_all_channels(st, st->scan_cnt, NULL);
893 		else
894 			ret = ad7280_read_channel(st, chan->address >> 8,
895 						  chan->address & 0xFF);
896 		mutex_unlock(&st->lock);
897 
898 		if (ret < 0)
899 			return ret;
900 
901 		*val = ret;
902 
903 		return IIO_VAL_INT;
904 	case IIO_CHAN_INFO_SCALE:
905 		if ((chan->address & 0xFF) <= AD7280A_CELL_VOLTAGE_6_REG)
906 			*val = 4000;
907 		else
908 			*val = 5000;
909 
910 		*val2 = AD7280A_BITS;
911 		return IIO_VAL_FRACTIONAL_LOG2;
912 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
913 		*val = ad7280a_n_avg[st->oversampling_ratio];
914 		return IIO_VAL_INT;
915 	}
916 	return -EINVAL;
917 }
918 
ad7280_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)919 static int ad7280_write_raw(struct iio_dev *indio_dev,
920 			    struct iio_chan_spec const *chan,
921 			    int val, int val2, long mask)
922 {
923 	struct ad7280_state *st = iio_priv(indio_dev);
924 	int i;
925 
926 	switch (mask) {
927 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
928 		if (val2 != 0)
929 			return -EINVAL;
930 		for (i = 0; i < ARRAY_SIZE(ad7280a_n_avg); i++) {
931 			if (val == ad7280a_n_avg[i]) {
932 				st->oversampling_ratio = i;
933 				ad7280_update_delay(st);
934 				return 0;
935 			}
936 		}
937 		return -EINVAL;
938 	default:
939 		return -EINVAL;
940 	}
941 }
942 
943 static const struct iio_info ad7280_info = {
944 	.read_raw = ad7280_read_raw,
945 	.write_raw = ad7280_write_raw,
946 	.read_event_value = &ad7280a_read_thresh,
947 	.write_event_value = &ad7280a_write_thresh,
948 };
949 
950 static const struct iio_info ad7280_info_no_irq = {
951 	.read_raw = ad7280_read_raw,
952 	.write_raw = ad7280_write_raw,
953 };
954 
ad7280_probe(struct spi_device * spi)955 static int ad7280_probe(struct spi_device *spi)
956 {
957 	struct device *dev = &spi->dev;
958 	struct ad7280_state *st;
959 	int ret;
960 	struct iio_dev *indio_dev;
961 
962 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
963 	if (!indio_dev)
964 		return -ENOMEM;
965 
966 	st = iio_priv(indio_dev);
967 	spi_set_drvdata(spi, indio_dev);
968 	st->spi = spi;
969 	mutex_init(&st->lock);
970 
971 	st->thermistor_term_en =
972 		device_property_read_bool(dev, "adi,thermistor-termination");
973 
974 	if (device_property_present(dev, "adi,acquisition-time-ns")) {
975 		u32 val;
976 
977 		ret = device_property_read_u32(dev, "adi,acquisition-time-ns", &val);
978 		if (ret)
979 			return ret;
980 
981 		switch (val) {
982 		case 400:
983 			st->acquisition_time = AD7280A_CTRL_LB_ACQ_TIME_400ns;
984 			break;
985 		case 800:
986 			st->acquisition_time = AD7280A_CTRL_LB_ACQ_TIME_800ns;
987 			break;
988 		case 1200:
989 			st->acquisition_time = AD7280A_CTRL_LB_ACQ_TIME_1200ns;
990 			break;
991 		case 1600:
992 			st->acquisition_time = AD7280A_CTRL_LB_ACQ_TIME_1600ns;
993 			break;
994 		default:
995 			dev_err(dev, "Firmware provided acquisition time is invalid\n");
996 			return -EINVAL;
997 		}
998 	} else {
999 		st->acquisition_time = AD7280A_CTRL_LB_ACQ_TIME_400ns;
1000 	}
1001 
1002 	/* Alert masks are intended for when particular inputs are not wired up */
1003 	if (device_property_present(dev, "adi,voltage-alert-last-chan")) {
1004 		u32 val;
1005 
1006 		ret = device_property_read_u32(dev, "adi,voltage-alert-last-chan", &val);
1007 		if (ret)
1008 			return ret;
1009 
1010 		switch (val) {
1011 		case 3:
1012 			st->chain_last_alert_ignore |= AD7280A_ALERT_REMOVE_VIN4_VIN5;
1013 			break;
1014 		case 4:
1015 			st->chain_last_alert_ignore |= AD7280A_ALERT_REMOVE_VIN5;
1016 			break;
1017 		case 5:
1018 			break;
1019 		default:
1020 			dev_err(dev,
1021 				"Firmware provided last voltage alert channel invalid\n");
1022 			break;
1023 		}
1024 	}
1025 	crc8_populate_msb(st->crc_tab, POLYNOM);
1026 
1027 	st->spi->max_speed_hz = AD7280A_MAX_SPI_CLK_HZ;
1028 	st->spi->mode = SPI_MODE_1;
1029 	spi_setup(st->spi);
1030 
1031 	st->ctrl_lb = FIELD_PREP(AD7280A_CTRL_LB_ACQ_TIME_MSK, st->acquisition_time) |
1032 		FIELD_PREP(AD7280A_CTRL_LB_THERMISTOR_MSK, st->thermistor_term_en);
1033 	st->oversampling_ratio = 0; /* No oversampling */
1034 
1035 	ret = ad7280_chain_setup(st);
1036 	if (ret < 0)
1037 		return ret;
1038 
1039 	st->slave_num = ret;
1040 	st->scan_cnt = (st->slave_num + 1) * AD7280A_NUM_CH;
1041 	st->cell_threshhigh = 0xFF;
1042 	st->aux_threshhigh = 0xFF;
1043 
1044 	ret = devm_add_action_or_reset(dev, ad7280_sw_power_down, st);
1045 	if (ret)
1046 		return ret;
1047 
1048 	ad7280_update_delay(st);
1049 
1050 	indio_dev->name = spi_get_device_id(spi)->name;
1051 	indio_dev->modes = INDIO_DIRECT_MODE;
1052 
1053 	ret = ad7280_channel_init(st, spi->irq > 0);
1054 	if (ret < 0)
1055 		return ret;
1056 
1057 	indio_dev->num_channels = ret;
1058 	indio_dev->channels = st->channels;
1059 	if (spi->irq > 0) {
1060 		ret = ad7280_write(st, AD7280A_DEVADDR_MASTER,
1061 				   AD7280A_ALERT_REG, 1,
1062 				   AD7280A_ALERT_RELAY_SIG_CHAIN_DOWN);
1063 		if (ret)
1064 			return ret;
1065 
1066 		ret = ad7280_write(st, ad7280a_devaddr(st->slave_num),
1067 				   AD7280A_ALERT_REG, 0,
1068 				   AD7280A_ALERT_GEN_STATIC_HIGH |
1069 				   FIELD_PREP(AD7280A_ALERT_REMOVE_MSK,
1070 					      st->chain_last_alert_ignore));
1071 		if (ret)
1072 			return ret;
1073 
1074 		ret = devm_request_threaded_irq(dev, spi->irq,
1075 						NULL,
1076 						ad7280_event_handler,
1077 						IRQF_TRIGGER_FALLING |
1078 						IRQF_ONESHOT,
1079 						indio_dev->name,
1080 						indio_dev);
1081 		if (ret)
1082 			return ret;
1083 
1084 		indio_dev->info = &ad7280_info;
1085 	} else {
1086 		indio_dev->info = &ad7280_info_no_irq;
1087 	}
1088 
1089 	return devm_iio_device_register(dev, indio_dev);
1090 }
1091 
1092 static const struct spi_device_id ad7280_id[] = {
1093 	{ "ad7280a", 0 },
1094 	{ }
1095 };
1096 MODULE_DEVICE_TABLE(spi, ad7280_id);
1097 
1098 static struct spi_driver ad7280_driver = {
1099 	.driver = {
1100 		.name	= "ad7280",
1101 	},
1102 	.probe		= ad7280_probe,
1103 	.id_table	= ad7280_id,
1104 };
1105 module_spi_driver(ad7280_driver);
1106 
1107 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
1108 MODULE_DESCRIPTION("Analog Devices AD7280A");
1109 MODULE_LICENSE("GPL v2");
1110