1/*
2 * AD7280A Lithium Ion Battery Monitoring System
3 *
4 * Copyright 2011 Analog Devices Inc.
5 *
6 * Licensed under the GPL-2.
7 */
8
9#include <linux/device.h>
10#include <linux/kernel.h>
11#include <linux/slab.h>
12#include <linux/sysfs.h>
13#include <linux/spi/spi.h>
14#include <linux/err.h>
15#include <linux/delay.h>
16#include <linux/interrupt.h>
17#include <linux/module.h>
18
19#include <linux/iio/iio.h>
20#include <linux/iio/sysfs.h>
21#include <linux/iio/events.h>
22
23#include "ad7280a.h"
24
25/* Registers */
26#define AD7280A_CELL_VOLTAGE_1		0x0  /* D11 to D0, Read only */
27#define AD7280A_CELL_VOLTAGE_2		0x1  /* D11 to D0, Read only */
28#define AD7280A_CELL_VOLTAGE_3		0x2  /* D11 to D0, Read only */
29#define AD7280A_CELL_VOLTAGE_4		0x3  /* D11 to D0, Read only */
30#define AD7280A_CELL_VOLTAGE_5		0x4  /* D11 to D0, Read only */
31#define AD7280A_CELL_VOLTAGE_6		0x5  /* D11 to D0, Read only */
32#define AD7280A_AUX_ADC_1		0x6  /* D11 to D0, Read only */
33#define AD7280A_AUX_ADC_2		0x7  /* D11 to D0, Read only */
34#define AD7280A_AUX_ADC_3		0x8  /* D11 to D0, Read only */
35#define AD7280A_AUX_ADC_4		0x9  /* D11 to D0, Read only */
36#define AD7280A_AUX_ADC_5		0xA  /* D11 to D0, Read only */
37#define AD7280A_AUX_ADC_6		0xB  /* D11 to D0, Read only */
38#define AD7280A_SELF_TEST		0xC  /* D11 to D0, Read only */
39#define AD7280A_CONTROL_HB		0xD  /* D15 to D8, Read/write */
40#define AD7280A_CONTROL_LB		0xE  /* D7 to D0, Read/write */
41#define AD7280A_CELL_OVERVOLTAGE	0xF  /* D7 to D0, Read/write */
42#define AD7280A_CELL_UNDERVOLTAGE	0x10 /* D7 to D0, Read/write */
43#define AD7280A_AUX_ADC_OVERVOLTAGE	0x11 /* D7 to D0, Read/write */
44#define AD7280A_AUX_ADC_UNDERVOLTAGE	0x12 /* D7 to D0, Read/write */
45#define AD7280A_ALERT			0x13 /* D7 to D0, Read/write */
46#define AD7280A_CELL_BALANCE		0x14 /* D7 to D0, Read/write */
47#define AD7280A_CB1_TIMER		0x15 /* D7 to D0, Read/write */
48#define AD7280A_CB2_TIMER		0x16 /* D7 to D0, Read/write */
49#define AD7280A_CB3_TIMER		0x17 /* D7 to D0, Read/write */
50#define AD7280A_CB4_TIMER		0x18 /* D7 to D0, Read/write */
51#define AD7280A_CB5_TIMER		0x19 /* D7 to D0, Read/write */
52#define AD7280A_CB6_TIMER		0x1A /* D7 to D0, Read/write */
53#define AD7280A_PD_TIMER		0x1B /* D7 to D0, Read/write */
54#define AD7280A_READ			0x1C /* D7 to D0, Read/write */
55#define AD7280A_CNVST_CONTROL		0x1D /* D7 to D0, Read/write */
56
57/* Bits and Masks */
58#define AD7280A_CTRL_HB_CONV_INPUT_ALL			0
59#define AD7280A_CTRL_HB_CONV_INPUT_6CELL_AUX1_3_4	BIT(6)
60#define AD7280A_CTRL_HB_CONV_INPUT_6CELL		BIT(7)
61#define AD7280A_CTRL_HB_CONV_INPUT_SELF_TEST		(BIT(7) | BIT(6))
62#define AD7280A_CTRL_HB_CONV_RES_READ_ALL		0
63#define AD7280A_CTRL_HB_CONV_RES_READ_6CELL_AUX1_3_4	BIT(4)
64#define AD7280A_CTRL_HB_CONV_RES_READ_6CELL		BIT(5)
65#define AD7280A_CTRL_HB_CONV_RES_READ_NO		(BIT(5) | BIT(4))
66#define AD7280A_CTRL_HB_CONV_START_CNVST		0
67#define AD7280A_CTRL_HB_CONV_START_CS			BIT(3)
68#define AD7280A_CTRL_HB_CONV_AVG_DIS			0
69#define AD7280A_CTRL_HB_CONV_AVG_2			BIT(1)
70#define AD7280A_CTRL_HB_CONV_AVG_4			BIT(2)
71#define AD7280A_CTRL_HB_CONV_AVG_8			(BIT(2) | BIT(1))
72#define AD7280A_CTRL_HB_CONV_AVG(x)			((x) << 1)
73#define AD7280A_CTRL_HB_PWRDN_SW			BIT(0)
74
75#define AD7280A_CTRL_LB_SWRST				BIT(7)
76#define AD7280A_CTRL_LB_ACQ_TIME_400ns			0
77#define AD7280A_CTRL_LB_ACQ_TIME_800ns			BIT(5)
78#define AD7280A_CTRL_LB_ACQ_TIME_1200ns			BIT(6)
79#define AD7280A_CTRL_LB_ACQ_TIME_1600ns			(BIT(6) | BIT(5))
80#define AD7280A_CTRL_LB_ACQ_TIME(x)			((x) << 5)
81#define AD7280A_CTRL_LB_MUST_SET			BIT(4)
82#define AD7280A_CTRL_LB_THERMISTOR_EN			BIT(3)
83#define AD7280A_CTRL_LB_LOCK_DEV_ADDR			BIT(2)
84#define AD7280A_CTRL_LB_INC_DEV_ADDR			BIT(1)
85#define AD7280A_CTRL_LB_DAISY_CHAIN_RB_EN		BIT(0)
86
87#define AD7280A_ALERT_GEN_STATIC_HIGH			BIT(6)
88#define AD7280A_ALERT_RELAY_SIG_CHAIN_DOWN		(BIT(7) | BIT(6))
89
90#define AD7280A_ALL_CELLS				(0xAD << 16)
91
92#define AD7280A_MAX_SPI_CLK_Hz		700000 /* < 1MHz */
93#define AD7280A_MAX_CHAIN		8
94#define AD7280A_CELLS_PER_DEV		6
95#define AD7280A_BITS			12
96#define AD7280A_NUM_CH			(AD7280A_AUX_ADC_6 - \
97					AD7280A_CELL_VOLTAGE_1 + 1)
98
99#define AD7280A_DEVADDR_MASTER		0
100#define AD7280A_DEVADDR_ALL		0x1F
101/* 5-bit device address is sent LSB first */
102#define AD7280A_DEVADDR(addr)	(((addr & 0x1) << 4) | ((addr & 0x2) << 3) | \
103				(addr & 0x4) | ((addr & 0x8) >> 3) | \
104				((addr & 0x10) >> 4))
105
106/* During a read a valid write is mandatory.
107 * So writing to the highest available address (Address 0x1F)
108 * and setting the address all parts bit to 0 is recommended
109 * So the TXVAL is AD7280A_DEVADDR_ALL + CRC
110 */
111#define AD7280A_READ_TXVAL	0xF800030A
112
113/*
114 * AD7280 CRC
115 *
116 * P(x) = x^8 + x^5 + x^3 + x^2 + x^1 + x^0 = 0b100101111 => 0x2F
117 */
118#define POLYNOM		0x2F
119#define POLYNOM_ORDER	8
120#define HIGHBIT		(1 << (POLYNOM_ORDER - 1))
121
122struct ad7280_state {
123	struct spi_device		*spi;
124	struct iio_chan_spec		*channels;
125	struct iio_dev_attr		*iio_attr;
126	int				slave_num;
127	int				scan_cnt;
128	int				readback_delay_us;
129	unsigned char			crc_tab[256];
130	unsigned char			ctrl_hb;
131	unsigned char			ctrl_lb;
132	unsigned char			cell_threshhigh;
133	unsigned char			cell_threshlow;
134	unsigned char			aux_threshhigh;
135	unsigned char			aux_threshlow;
136	unsigned char			cb_mask[AD7280A_MAX_CHAIN];
137
138	__be32				buf[2] ____cacheline_aligned;
139};
140
141static void ad7280_crc8_build_table(unsigned char *crc_tab)
142{
143	unsigned char bit, crc;
144	int cnt, i;
145
146	for (cnt = 0; cnt < 256; cnt++) {
147		crc = cnt;
148		for (i = 0; i < 8; i++) {
149			bit = crc & HIGHBIT;
150			crc <<= 1;
151			if (bit)
152				crc ^= POLYNOM;
153		}
154		crc_tab[cnt] = crc;
155	}
156}
157
158static unsigned char ad7280_calc_crc8(unsigned char *crc_tab, unsigned val)
159{
160	unsigned char crc;
161
162	crc = crc_tab[val >> 16 & 0xFF];
163	crc = crc_tab[crc ^ (val >> 8 & 0xFF)];
164
165	return  crc ^ (val & 0xFF);
166}
167
168static int ad7280_check_crc(struct ad7280_state *st, unsigned val)
169{
170	unsigned char crc = ad7280_calc_crc8(st->crc_tab, val >> 10);
171
172	if (crc != ((val >> 2) & 0xFF))
173		return -EIO;
174
175	return 0;
176}
177
178/* After initiating a conversion sequence we need to wait until the
179 * conversion is done. The delay is typically in the range of 15..30 us
180 * however depending an the number of devices in the daisy chain and the
181 * number of averages taken, conversion delays and acquisition time options
182 * it may take up to 250us, in this case we better sleep instead of busy
183 * wait.
184 */
185
186static void ad7280_delay(struct ad7280_state *st)
187{
188	if (st->readback_delay_us < 50)
189		udelay(st->readback_delay_us);
190	else
191		usleep_range(250, 500);
192}
193
194static int __ad7280_read32(struct ad7280_state *st, unsigned *val)
195{
196	int ret;
197	struct spi_transfer t = {
198		.tx_buf	= &st->buf[0],
199		.rx_buf = &st->buf[1],
200		.len = 4,
201	};
202
203	st->buf[0] = cpu_to_be32(AD7280A_READ_TXVAL);
204
205	ret = spi_sync_transfer(st->spi, &t, 1);
206	if (ret)
207		return ret;
208
209	*val = be32_to_cpu(st->buf[1]);
210
211	return 0;
212}
213
214static int ad7280_write(struct ad7280_state *st, unsigned devaddr,
215			unsigned addr, bool all, unsigned val)
216{
217	unsigned reg = (devaddr << 27 | addr << 21 |
218			(val & 0xFF) << 13 | all << 12);
219
220	reg |= ad7280_calc_crc8(st->crc_tab, reg >> 11) << 3 | 0x2;
221	st->buf[0] = cpu_to_be32(reg);
222
223	return spi_write(st->spi, &st->buf[0], 4);
224}
225
226static int ad7280_read(struct ad7280_state *st, unsigned devaddr,
227			unsigned addr)
228{
229	int ret;
230	unsigned tmp;
231
232	/* turns off the read operation on all parts */
233	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_HB, 1,
234			AD7280A_CTRL_HB_CONV_INPUT_ALL |
235			AD7280A_CTRL_HB_CONV_RES_READ_NO |
236			st->ctrl_hb);
237	if (ret)
238		return ret;
239
240	/* turns on the read operation on the addressed part */
241	ret = ad7280_write(st, devaddr, AD7280A_CONTROL_HB, 0,
242			AD7280A_CTRL_HB_CONV_INPUT_ALL |
243			AD7280A_CTRL_HB_CONV_RES_READ_ALL |
244			st->ctrl_hb);
245	if (ret)
246		return ret;
247
248	/* Set register address on the part to be read from */
249	ret = ad7280_write(st, devaddr, AD7280A_READ, 0, addr << 2);
250	if (ret)
251		return ret;
252
253	__ad7280_read32(st, &tmp);
254
255	if (ad7280_check_crc(st, tmp))
256		return -EIO;
257
258	if (((tmp >> 27) != devaddr) || (((tmp >> 21) & 0x3F) != addr))
259		return -EFAULT;
260
261	return (tmp >> 13) & 0xFF;
262}
263
264static int ad7280_read_channel(struct ad7280_state *st, unsigned devaddr,
265			       unsigned addr)
266{
267	int ret;
268	unsigned tmp;
269
270	ret = ad7280_write(st, devaddr, AD7280A_READ, 0, addr << 2);
271	if (ret)
272		return ret;
273
274	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_HB, 1,
275			AD7280A_CTRL_HB_CONV_INPUT_ALL |
276			AD7280A_CTRL_HB_CONV_RES_READ_NO |
277			st->ctrl_hb);
278	if (ret)
279		return ret;
280
281	ret = ad7280_write(st, devaddr, AD7280A_CONTROL_HB, 0,
282			AD7280A_CTRL_HB_CONV_INPUT_ALL |
283			AD7280A_CTRL_HB_CONV_RES_READ_ALL |
284			AD7280A_CTRL_HB_CONV_START_CS |
285			st->ctrl_hb);
286	if (ret)
287		return ret;
288
289	ad7280_delay(st);
290
291	__ad7280_read32(st, &tmp);
292
293	if (ad7280_check_crc(st, tmp))
294		return -EIO;
295
296	if (((tmp >> 27) != devaddr) || (((tmp >> 23) & 0xF) != addr))
297		return -EFAULT;
298
299	return (tmp >> 11) & 0xFFF;
300}
301
302static int ad7280_read_all_channels(struct ad7280_state *st, unsigned cnt,
303			     unsigned *array)
304{
305	int i, ret;
306	unsigned tmp, sum = 0;
307
308	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_READ, 1,
309			   AD7280A_CELL_VOLTAGE_1 << 2);
310	if (ret)
311		return ret;
312
313	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_HB, 1,
314			AD7280A_CTRL_HB_CONV_INPUT_ALL |
315			AD7280A_CTRL_HB_CONV_RES_READ_ALL |
316			AD7280A_CTRL_HB_CONV_START_CS |
317			st->ctrl_hb);
318	if (ret)
319		return ret;
320
321	ad7280_delay(st);
322
323	for (i = 0; i < cnt; i++) {
324		__ad7280_read32(st, &tmp);
325
326		if (ad7280_check_crc(st, tmp))
327			return -EIO;
328
329		if (array)
330			array[i] = tmp;
331		/* only sum cell voltages */
332		if (((tmp >> 23) & 0xF) <= AD7280A_CELL_VOLTAGE_6)
333			sum += ((tmp >> 11) & 0xFFF);
334	}
335
336	return sum;
337}
338
339static int ad7280_chain_setup(struct ad7280_state *st)
340{
341	unsigned val, n;
342	int ret;
343
344	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_LB, 1,
345			AD7280A_CTRL_LB_DAISY_CHAIN_RB_EN |
346			AD7280A_CTRL_LB_LOCK_DEV_ADDR |
347			AD7280A_CTRL_LB_MUST_SET |
348			AD7280A_CTRL_LB_SWRST |
349			st->ctrl_lb);
350	if (ret)
351		return ret;
352
353	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_LB, 1,
354			AD7280A_CTRL_LB_DAISY_CHAIN_RB_EN |
355			AD7280A_CTRL_LB_LOCK_DEV_ADDR |
356			AD7280A_CTRL_LB_MUST_SET |
357			st->ctrl_lb);
358	if (ret)
359		return ret;
360
361	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_READ, 1,
362			AD7280A_CONTROL_LB << 2);
363	if (ret)
364		return ret;
365
366	for (n = 0; n <= AD7280A_MAX_CHAIN; n++) {
367		__ad7280_read32(st, &val);
368		if (val == 0)
369			return n - 1;
370
371		if (ad7280_check_crc(st, val))
372			return -EIO;
373
374		if (n != AD7280A_DEVADDR(val >> 27))
375			return -EIO;
376	}
377
378	return -EFAULT;
379}
380
381static ssize_t ad7280_show_balance_sw(struct device *dev,
382					struct device_attribute *attr,
383					char *buf)
384{
385	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
386	struct ad7280_state *st = iio_priv(indio_dev);
387	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
388
389	return sprintf(buf, "%d\n",
390		       !!(st->cb_mask[this_attr->address >> 8] &
391		       (1 << ((this_attr->address & 0xFF) + 2))));
392}
393
394static ssize_t ad7280_store_balance_sw(struct device *dev,
395					 struct device_attribute *attr,
396					 const char *buf,
397					 size_t len)
398{
399	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
400	struct ad7280_state *st = iio_priv(indio_dev);
401	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
402	bool readin;
403	int ret;
404	unsigned devaddr, ch;
405
406	ret = strtobool(buf, &readin);
407	if (ret)
408		return ret;
409
410	devaddr = this_attr->address >> 8;
411	ch = this_attr->address & 0xFF;
412
413	mutex_lock(&indio_dev->mlock);
414	if (readin)
415		st->cb_mask[devaddr] |= 1 << (ch + 2);
416	else
417		st->cb_mask[devaddr] &= ~(1 << (ch + 2));
418
419	ret = ad7280_write(st, devaddr, AD7280A_CELL_BALANCE,
420			   0, st->cb_mask[devaddr]);
421	mutex_unlock(&indio_dev->mlock);
422
423	return ret ? ret : len;
424}
425
426static ssize_t ad7280_show_balance_timer(struct device *dev,
427					struct device_attribute *attr,
428					char *buf)
429{
430	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
431	struct ad7280_state *st = iio_priv(indio_dev);
432	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
433	int ret;
434	unsigned msecs;
435
436	mutex_lock(&indio_dev->mlock);
437	ret = ad7280_read(st, this_attr->address >> 8,
438			this_attr->address & 0xFF);
439	mutex_unlock(&indio_dev->mlock);
440
441	if (ret < 0)
442		return ret;
443
444	msecs = (ret >> 3) * 71500;
445
446	return sprintf(buf, "%u\n", msecs);
447}
448
449static ssize_t ad7280_store_balance_timer(struct device *dev,
450					 struct device_attribute *attr,
451					 const char *buf,
452					 size_t len)
453{
454	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
455	struct ad7280_state *st = iio_priv(indio_dev);
456	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
457	unsigned long val;
458	int ret;
459
460	ret = kstrtoul(buf, 10, &val);
461	if (ret)
462		return ret;
463
464	val /= 71500;
465
466	if (val > 31)
467		return -EINVAL;
468
469	mutex_lock(&indio_dev->mlock);
470	ret = ad7280_write(st, this_attr->address >> 8,
471			   this_attr->address & 0xFF,
472			   0, (val & 0x1F) << 3);
473	mutex_unlock(&indio_dev->mlock);
474
475	return ret ? ret : len;
476}
477
478static struct attribute *ad7280_attributes[AD7280A_MAX_CHAIN *
479					   AD7280A_CELLS_PER_DEV * 2 + 1];
480
481static struct attribute_group ad7280_attrs_group = {
482	.attrs = ad7280_attributes,
483};
484
485static int ad7280_channel_init(struct ad7280_state *st)
486{
487	int dev, ch, cnt;
488
489	st->channels = kcalloc((st->slave_num + 1) * 12 + 2,
490			       sizeof(*st->channels), GFP_KERNEL);
491	if (st->channels == NULL)
492		return -ENOMEM;
493
494	for (dev = 0, cnt = 0; dev <= st->slave_num; dev++)
495		for (ch = AD7280A_CELL_VOLTAGE_1; ch <= AD7280A_AUX_ADC_6; ch++,
496			cnt++) {
497			if (ch < AD7280A_AUX_ADC_1) {
498				st->channels[cnt].type = IIO_VOLTAGE;
499				st->channels[cnt].differential = 1;
500				st->channels[cnt].channel = (dev * 6) + ch;
501				st->channels[cnt].channel2 =
502					st->channels[cnt].channel + 1;
503			} else {
504				st->channels[cnt].type = IIO_TEMP;
505				st->channels[cnt].channel = (dev * 6) + ch - 6;
506			}
507			st->channels[cnt].indexed = 1;
508			st->channels[cnt].info_mask_separate =
509				BIT(IIO_CHAN_INFO_RAW);
510			st->channels[cnt].info_mask_shared_by_type =
511				BIT(IIO_CHAN_INFO_SCALE);
512			st->channels[cnt].address =
513				AD7280A_DEVADDR(dev) << 8 | ch;
514			st->channels[cnt].scan_index = cnt;
515			st->channels[cnt].scan_type.sign = 'u';
516			st->channels[cnt].scan_type.realbits = 12;
517			st->channels[cnt].scan_type.storagebits = 32;
518			st->channels[cnt].scan_type.shift = 0;
519		}
520
521	st->channels[cnt].type = IIO_VOLTAGE;
522	st->channels[cnt].differential = 1;
523	st->channels[cnt].channel = 0;
524	st->channels[cnt].channel2 = dev * 6;
525	st->channels[cnt].address = AD7280A_ALL_CELLS;
526	st->channels[cnt].indexed = 1;
527	st->channels[cnt].info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
528	st->channels[cnt].info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
529	st->channels[cnt].scan_index = cnt;
530	st->channels[cnt].scan_type.sign = 'u';
531	st->channels[cnt].scan_type.realbits = 32;
532	st->channels[cnt].scan_type.storagebits = 32;
533	st->channels[cnt].scan_type.shift = 0;
534	cnt++;
535	st->channels[cnt].type = IIO_TIMESTAMP;
536	st->channels[cnt].channel = -1;
537	st->channels[cnt].scan_index = cnt;
538	st->channels[cnt].scan_type.sign = 's';
539	st->channels[cnt].scan_type.realbits = 64;
540	st->channels[cnt].scan_type.storagebits = 64;
541	st->channels[cnt].scan_type.shift = 0;
542
543	return cnt + 1;
544}
545
546static int ad7280_attr_init(struct ad7280_state *st)
547{
548	int dev, ch, cnt;
549
550	st->iio_attr = kcalloc(2, sizeof(*st->iio_attr) *
551			       (st->slave_num + 1) * AD7280A_CELLS_PER_DEV,
552			       GFP_KERNEL);
553	if (st->iio_attr == NULL)
554		return -ENOMEM;
555
556	for (dev = 0, cnt = 0; dev <= st->slave_num; dev++)
557		for (ch = AD7280A_CELL_VOLTAGE_1; ch <= AD7280A_CELL_VOLTAGE_6;
558			ch++, cnt++) {
559			st->iio_attr[cnt].address =
560				AD7280A_DEVADDR(dev) << 8 | ch;
561			st->iio_attr[cnt].dev_attr.attr.mode =
562				S_IWUSR | S_IRUGO;
563			st->iio_attr[cnt].dev_attr.show =
564				ad7280_show_balance_sw;
565			st->iio_attr[cnt].dev_attr.store =
566				ad7280_store_balance_sw;
567			st->iio_attr[cnt].dev_attr.attr.name =
568				kasprintf(GFP_KERNEL,
569					"in%d-in%d_balance_switch_en",
570					(dev * AD7280A_CELLS_PER_DEV) + ch,
571					(dev * AD7280A_CELLS_PER_DEV) + ch + 1);
572			ad7280_attributes[cnt] =
573				&st->iio_attr[cnt].dev_attr.attr;
574			cnt++;
575			st->iio_attr[cnt].address =
576				AD7280A_DEVADDR(dev) << 8 |
577				(AD7280A_CB1_TIMER + ch);
578			st->iio_attr[cnt].dev_attr.attr.mode =
579				S_IWUSR | S_IRUGO;
580			st->iio_attr[cnt].dev_attr.show =
581				ad7280_show_balance_timer;
582			st->iio_attr[cnt].dev_attr.store =
583				ad7280_store_balance_timer;
584			st->iio_attr[cnt].dev_attr.attr.name =
585				kasprintf(GFP_KERNEL, "in%d-in%d_balance_timer",
586					(dev * AD7280A_CELLS_PER_DEV) + ch,
587					(dev * AD7280A_CELLS_PER_DEV) + ch + 1);
588			ad7280_attributes[cnt] =
589				&st->iio_attr[cnt].dev_attr.attr;
590		}
591
592	ad7280_attributes[cnt] = NULL;
593
594	return 0;
595}
596
597static ssize_t ad7280_read_channel_config(struct device *dev,
598					struct device_attribute *attr,
599					char *buf)
600{
601	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
602	struct ad7280_state *st = iio_priv(indio_dev);
603	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
604	unsigned val;
605
606	switch ((u32) this_attr->address) {
607	case AD7280A_CELL_OVERVOLTAGE:
608		val = 1000 + (st->cell_threshhigh * 1568) / 100;
609		break;
610	case AD7280A_CELL_UNDERVOLTAGE:
611		val = 1000 + (st->cell_threshlow * 1568) / 100;
612		break;
613	case AD7280A_AUX_ADC_OVERVOLTAGE:
614		val = (st->aux_threshhigh * 196) / 10;
615		break;
616	case AD7280A_AUX_ADC_UNDERVOLTAGE:
617		val = (st->aux_threshlow * 196) / 10;
618		break;
619	default:
620		return -EINVAL;
621	}
622
623	return sprintf(buf, "%u\n", val);
624}
625
626static ssize_t ad7280_write_channel_config(struct device *dev,
627					 struct device_attribute *attr,
628					 const char *buf,
629					 size_t len)
630{
631	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
632	struct ad7280_state *st = iio_priv(indio_dev);
633	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
634
635	long val;
636	int ret;
637
638	ret = kstrtol(buf, 10, &val);
639	if (ret)
640		return ret;
641
642	switch ((u32) this_attr->address) {
643	case AD7280A_CELL_OVERVOLTAGE:
644	case AD7280A_CELL_UNDERVOLTAGE:
645		val = ((val - 1000) * 100) / 1568; /* LSB 15.68mV */
646		break;
647	case AD7280A_AUX_ADC_OVERVOLTAGE:
648	case AD7280A_AUX_ADC_UNDERVOLTAGE:
649		val = (val * 10) / 196; /* LSB 19.6mV */
650		break;
651	default:
652		return -EFAULT;
653	}
654
655	val = clamp(val, 0L, 0xFFL);
656
657	mutex_lock(&indio_dev->mlock);
658	switch ((u32) this_attr->address) {
659	case AD7280A_CELL_OVERVOLTAGE:
660		st->cell_threshhigh = val;
661		break;
662	case AD7280A_CELL_UNDERVOLTAGE:
663		st->cell_threshlow = val;
664		break;
665	case AD7280A_AUX_ADC_OVERVOLTAGE:
666		st->aux_threshhigh = val;
667		break;
668	case AD7280A_AUX_ADC_UNDERVOLTAGE:
669		st->aux_threshlow = val;
670		break;
671	}
672
673	ret = ad7280_write(st, AD7280A_DEVADDR_MASTER,
674			   this_attr->address, 1, val);
675
676	mutex_unlock(&indio_dev->mlock);
677
678	return ret ? ret : len;
679}
680
681static irqreturn_t ad7280_event_handler(int irq, void *private)
682{
683	struct iio_dev *indio_dev = private;
684	struct ad7280_state *st = iio_priv(indio_dev);
685	unsigned *channels;
686	int i, ret;
687
688	channels = kcalloc(st->scan_cnt, sizeof(*channels), GFP_KERNEL);
689	if (channels == NULL)
690		return IRQ_HANDLED;
691
692	ret = ad7280_read_all_channels(st, st->scan_cnt, channels);
693	if (ret < 0)
694		goto out;
695
696	for (i = 0; i < st->scan_cnt; i++) {
697		if (((channels[i] >> 23) & 0xF) <= AD7280A_CELL_VOLTAGE_6) {
698			if (((channels[i] >> 11) & 0xFFF) >=
699				st->cell_threshhigh)
700				iio_push_event(indio_dev,
701					IIO_EVENT_CODE(IIO_VOLTAGE,
702						       1,
703						       0,
704						       IIO_EV_DIR_RISING,
705						       IIO_EV_TYPE_THRESH,
706						       0, 0, 0),
707					iio_get_time_ns());
708			else if (((channels[i] >> 11) & 0xFFF) <=
709				st->cell_threshlow)
710				iio_push_event(indio_dev,
711					IIO_EVENT_CODE(IIO_VOLTAGE,
712						       1,
713						       0,
714						       IIO_EV_DIR_FALLING,
715						       IIO_EV_TYPE_THRESH,
716						       0, 0, 0),
717					iio_get_time_ns());
718		} else {
719			if (((channels[i] >> 11) & 0xFFF) >= st->aux_threshhigh)
720				iio_push_event(indio_dev,
721					IIO_UNMOD_EVENT_CODE(IIO_TEMP,
722					0,
723					IIO_EV_TYPE_THRESH,
724					IIO_EV_DIR_RISING),
725					iio_get_time_ns());
726			else if (((channels[i] >> 11) & 0xFFF) <=
727				st->aux_threshlow)
728				iio_push_event(indio_dev,
729					IIO_UNMOD_EVENT_CODE(IIO_TEMP,
730					0,
731					IIO_EV_TYPE_THRESH,
732					IIO_EV_DIR_FALLING),
733					iio_get_time_ns());
734		}
735	}
736
737out:
738	kfree(channels);
739
740	return IRQ_HANDLED;
741}
742
743static IIO_DEVICE_ATTR_NAMED(in_thresh_low_value,
744		in_voltage-voltage_thresh_low_value,
745		S_IRUGO | S_IWUSR,
746		ad7280_read_channel_config,
747		ad7280_write_channel_config,
748		AD7280A_CELL_UNDERVOLTAGE);
749
750static IIO_DEVICE_ATTR_NAMED(in_thresh_high_value,
751		in_voltage-voltage_thresh_high_value,
752		S_IRUGO | S_IWUSR,
753		ad7280_read_channel_config,
754		ad7280_write_channel_config,
755		AD7280A_CELL_OVERVOLTAGE);
756
757static IIO_DEVICE_ATTR(in_temp_thresh_low_value,
758		S_IRUGO | S_IWUSR,
759		ad7280_read_channel_config,
760		ad7280_write_channel_config,
761		AD7280A_AUX_ADC_UNDERVOLTAGE);
762
763static IIO_DEVICE_ATTR(in_temp_thresh_high_value,
764		S_IRUGO | S_IWUSR,
765		ad7280_read_channel_config,
766		ad7280_write_channel_config,
767		AD7280A_AUX_ADC_OVERVOLTAGE);
768
769
770static struct attribute *ad7280_event_attributes[] = {
771	&iio_dev_attr_in_thresh_low_value.dev_attr.attr,
772	&iio_dev_attr_in_thresh_high_value.dev_attr.attr,
773	&iio_dev_attr_in_temp_thresh_low_value.dev_attr.attr,
774	&iio_dev_attr_in_temp_thresh_high_value.dev_attr.attr,
775	NULL,
776};
777
778static struct attribute_group ad7280_event_attrs_group = {
779	.attrs = ad7280_event_attributes,
780};
781
782static int ad7280_read_raw(struct iio_dev *indio_dev,
783			   struct iio_chan_spec const *chan,
784			   int *val,
785			   int *val2,
786			   long m)
787{
788	struct ad7280_state *st = iio_priv(indio_dev);
789	int ret;
790
791	switch (m) {
792	case IIO_CHAN_INFO_RAW:
793		mutex_lock(&indio_dev->mlock);
794		if (chan->address == AD7280A_ALL_CELLS)
795			ret = ad7280_read_all_channels(st, st->scan_cnt, NULL);
796		else
797			ret = ad7280_read_channel(st, chan->address >> 8,
798						  chan->address & 0xFF);
799		mutex_unlock(&indio_dev->mlock);
800
801		if (ret < 0)
802			return ret;
803
804		*val = ret;
805
806		return IIO_VAL_INT;
807	case IIO_CHAN_INFO_SCALE:
808		if ((chan->address & 0xFF) <= AD7280A_CELL_VOLTAGE_6)
809			*val = 4000;
810		else
811			*val = 5000;
812
813		*val2 = AD7280A_BITS;
814		return IIO_VAL_FRACTIONAL_LOG2;
815	}
816	return -EINVAL;
817}
818
819static const struct iio_info ad7280_info = {
820	.read_raw = &ad7280_read_raw,
821	.event_attrs = &ad7280_event_attrs_group,
822	.attrs = &ad7280_attrs_group,
823	.driver_module = THIS_MODULE,
824};
825
826static const struct ad7280_platform_data ad7793_default_pdata = {
827	.acquisition_time = AD7280A_ACQ_TIME_400ns,
828	.conversion_averaging = AD7280A_CONV_AVG_DIS,
829	.thermistor_term_en = true,
830};
831
832static int ad7280_probe(struct spi_device *spi)
833{
834	const struct ad7280_platform_data *pdata = spi->dev.platform_data;
835	struct ad7280_state *st;
836	int ret;
837	const unsigned short tACQ_ns[4] = {465, 1010, 1460, 1890};
838	const unsigned short nAVG[4] = {1, 2, 4, 8};
839	struct iio_dev *indio_dev;
840
841	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
842	if (indio_dev == NULL)
843		return -ENOMEM;
844
845	st = iio_priv(indio_dev);
846	spi_set_drvdata(spi, indio_dev);
847	st->spi = spi;
848
849	if (!pdata)
850		pdata = &ad7793_default_pdata;
851
852	ad7280_crc8_build_table(st->crc_tab);
853
854	st->spi->max_speed_hz = AD7280A_MAX_SPI_CLK_Hz;
855	st->spi->mode = SPI_MODE_1;
856	spi_setup(st->spi);
857
858	st->ctrl_lb = AD7280A_CTRL_LB_ACQ_TIME(pdata->acquisition_time & 0x3);
859	st->ctrl_hb = AD7280A_CTRL_HB_CONV_AVG(pdata->conversion_averaging
860			& 0x3) | (pdata->thermistor_term_en ?
861			AD7280A_CTRL_LB_THERMISTOR_EN : 0);
862
863	ret = ad7280_chain_setup(st);
864	if (ret < 0)
865		return ret;
866
867	st->slave_num = ret;
868	st->scan_cnt = (st->slave_num + 1) * AD7280A_NUM_CH;
869	st->cell_threshhigh = 0xFF;
870	st->aux_threshhigh = 0xFF;
871
872	/*
873	 * Total Conversion Time = ((tACQ + tCONV) *
874	 *			   (Number of Conversions per Part)) −
875	 *			   tACQ + ((N - 1) * tDELAY)
876	 *
877	 * Readback Delay = Total Conversion Time + tWAIT
878	 */
879
880	st->readback_delay_us =
881		((tACQ_ns[pdata->acquisition_time & 0x3] + 695) *
882		(AD7280A_NUM_CH * nAVG[pdata->conversion_averaging & 0x3]))
883		- tACQ_ns[pdata->acquisition_time & 0x3] +
884		st->slave_num * 250;
885
886	/* Convert to usecs */
887	st->readback_delay_us = DIV_ROUND_UP(st->readback_delay_us, 1000);
888	st->readback_delay_us += 5; /* Add tWAIT */
889
890	indio_dev->name = spi_get_device_id(spi)->name;
891	indio_dev->dev.parent = &spi->dev;
892	indio_dev->modes = INDIO_DIRECT_MODE;
893
894	ret = ad7280_channel_init(st);
895	if (ret < 0)
896		return ret;
897
898	indio_dev->num_channels = ret;
899	indio_dev->channels = st->channels;
900	indio_dev->info = &ad7280_info;
901
902	ret = ad7280_attr_init(st);
903	if (ret < 0)
904		goto error_free_channels;
905
906	ret = iio_device_register(indio_dev);
907	if (ret)
908		goto error_free_attr;
909
910	if (spi->irq > 0) {
911		ret = ad7280_write(st, AD7280A_DEVADDR_MASTER,
912				   AD7280A_ALERT, 1,
913				   AD7280A_ALERT_RELAY_SIG_CHAIN_DOWN);
914		if (ret)
915			goto error_unregister;
916
917		ret = ad7280_write(st, AD7280A_DEVADDR(st->slave_num),
918				   AD7280A_ALERT, 0,
919				   AD7280A_ALERT_GEN_STATIC_HIGH |
920				   (pdata->chain_last_alert_ignore & 0xF));
921		if (ret)
922			goto error_unregister;
923
924		ret = request_threaded_irq(spi->irq,
925					   NULL,
926					   ad7280_event_handler,
927					   IRQF_TRIGGER_FALLING |
928					   IRQF_ONESHOT,
929					   indio_dev->name,
930					   indio_dev);
931		if (ret)
932			goto error_unregister;
933	}
934
935	return 0;
936error_unregister:
937	iio_device_unregister(indio_dev);
938
939error_free_attr:
940	kfree(st->iio_attr);
941
942error_free_channels:
943	kfree(st->channels);
944
945	return ret;
946}
947
948static int ad7280_remove(struct spi_device *spi)
949{
950	struct iio_dev *indio_dev = spi_get_drvdata(spi);
951	struct ad7280_state *st = iio_priv(indio_dev);
952
953	if (spi->irq > 0)
954		free_irq(spi->irq, indio_dev);
955	iio_device_unregister(indio_dev);
956
957	ad7280_write(st, AD7280A_DEVADDR_MASTER, AD7280A_CONTROL_HB, 1,
958			AD7280A_CTRL_HB_PWRDN_SW | st->ctrl_hb);
959
960	kfree(st->channels);
961	kfree(st->iio_attr);
962
963	return 0;
964}
965
966static const struct spi_device_id ad7280_id[] = {
967	{"ad7280a", 0},
968	{}
969};
970MODULE_DEVICE_TABLE(spi, ad7280_id);
971
972static struct spi_driver ad7280_driver = {
973	.driver = {
974		.name	= "ad7280",
975		.owner	= THIS_MODULE,
976	},
977	.probe		= ad7280_probe,
978	.remove		= ad7280_remove,
979	.id_table	= ad7280_id,
980};
981module_spi_driver(ad7280_driver);
982
983MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
984MODULE_DESCRIPTION("Analog Devices AD7280A");
985MODULE_LICENSE("GPL v2");
986