1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * BMA220 Digital triaxial acceleration sensor driver
4 *
5 * Copyright (c) 2016,2020 Intel Corporation.
6 */
7
8#include <linux/bits.h>
9#include <linux/kernel.h>
10#include <linux/mod_devicetable.h>
11#include <linux/module.h>
12#include <linux/spi/spi.h>
13
14#include <linux/iio/buffer.h>
15#include <linux/iio/iio.h>
16#include <linux/iio/sysfs.h>
17#include <linux/iio/trigger_consumer.h>
18#include <linux/iio/triggered_buffer.h>
19
20#define BMA220_REG_ID				0x00
21#define BMA220_REG_ACCEL_X			0x02
22#define BMA220_REG_ACCEL_Y			0x03
23#define BMA220_REG_ACCEL_Z			0x04
24#define BMA220_REG_RANGE			0x11
25#define BMA220_REG_SUSPEND			0x18
26
27#define BMA220_CHIP_ID				0xDD
28#define BMA220_READ_MASK			BIT(7)
29#define BMA220_RANGE_MASK			GENMASK(1, 0)
30#define BMA220_SUSPEND_SLEEP			0xFF
31#define BMA220_SUSPEND_WAKE			0x00
32
33#define BMA220_DEVICE_NAME			"bma220"
34
35#define BMA220_ACCEL_CHANNEL(index, reg, axis) {			\
36	.type = IIO_ACCEL,						\
37	.address = reg,							\
38	.modified = 1,							\
39	.channel2 = IIO_MOD_##axis,					\
40	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
41	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),		\
42	.scan_index = index,						\
43	.scan_type = {							\
44		.sign = 's',						\
45		.realbits = 6,						\
46		.storagebits = 8,					\
47		.shift = 2,						\
48		.endianness = IIO_CPU,					\
49	},								\
50}
51
52enum bma220_axis {
53	AXIS_X,
54	AXIS_Y,
55	AXIS_Z,
56};
57
58static const int bma220_scale_table[][2] = {
59	{0, 623000}, {1, 248000}, {2, 491000}, {4, 983000},
60};
61
62struct bma220_data {
63	struct spi_device *spi_device;
64	struct mutex lock;
65	struct {
66		s8 chans[3];
67		/* Ensure timestamp is naturally aligned. */
68		s64 timestamp __aligned(8);
69	} scan;
70	u8 tx_buf[2] __aligned(IIO_DMA_MINALIGN);
71};
72
73static const struct iio_chan_spec bma220_channels[] = {
74	BMA220_ACCEL_CHANNEL(0, BMA220_REG_ACCEL_X, X),
75	BMA220_ACCEL_CHANNEL(1, BMA220_REG_ACCEL_Y, Y),
76	BMA220_ACCEL_CHANNEL(2, BMA220_REG_ACCEL_Z, Z),
77	IIO_CHAN_SOFT_TIMESTAMP(3),
78};
79
80static inline int bma220_read_reg(struct spi_device *spi, u8 reg)
81{
82	return spi_w8r8(spi, reg | BMA220_READ_MASK);
83}
84
85static const unsigned long bma220_accel_scan_masks[] = {
86	BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
87	0
88};
89
90static irqreturn_t bma220_trigger_handler(int irq, void *p)
91{
92	int ret;
93	struct iio_poll_func *pf = p;
94	struct iio_dev *indio_dev = pf->indio_dev;
95	struct bma220_data *data = iio_priv(indio_dev);
96	struct spi_device *spi = data->spi_device;
97
98	mutex_lock(&data->lock);
99	data->tx_buf[0] = BMA220_REG_ACCEL_X | BMA220_READ_MASK;
100	ret = spi_write_then_read(spi, data->tx_buf, 1, &data->scan.chans,
101				  ARRAY_SIZE(bma220_channels) - 1);
102	if (ret < 0)
103		goto err;
104
105	iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
106					   pf->timestamp);
107err:
108	mutex_unlock(&data->lock);
109	iio_trigger_notify_done(indio_dev->trig);
110
111	return IRQ_HANDLED;
112}
113
114static int bma220_read_raw(struct iio_dev *indio_dev,
115			   struct iio_chan_spec const *chan,
116			   int *val, int *val2, long mask)
117{
118	int ret;
119	u8 range_idx;
120	struct bma220_data *data = iio_priv(indio_dev);
121
122	switch (mask) {
123	case IIO_CHAN_INFO_RAW:
124		ret = bma220_read_reg(data->spi_device, chan->address);
125		if (ret < 0)
126			return -EINVAL;
127		*val = sign_extend32(ret >> chan->scan_type.shift,
128				     chan->scan_type.realbits - 1);
129		return IIO_VAL_INT;
130	case IIO_CHAN_INFO_SCALE:
131		ret = bma220_read_reg(data->spi_device, BMA220_REG_RANGE);
132		if (ret < 0)
133			return ret;
134		range_idx = ret & BMA220_RANGE_MASK;
135		*val = bma220_scale_table[range_idx][0];
136		*val2 = bma220_scale_table[range_idx][1];
137		return IIO_VAL_INT_PLUS_MICRO;
138	}
139
140	return -EINVAL;
141}
142
143static int bma220_write_raw(struct iio_dev *indio_dev,
144			    struct iio_chan_spec const *chan,
145			    int val, int val2, long mask)
146{
147	int i;
148	int ret;
149	int index = -1;
150	struct bma220_data *data = iio_priv(indio_dev);
151
152	switch (mask) {
153	case IIO_CHAN_INFO_SCALE:
154		for (i = 0; i < ARRAY_SIZE(bma220_scale_table); i++)
155			if (val == bma220_scale_table[i][0] &&
156			    val2 == bma220_scale_table[i][1]) {
157				index = i;
158				break;
159			}
160		if (index < 0)
161			return -EINVAL;
162
163		mutex_lock(&data->lock);
164		data->tx_buf[0] = BMA220_REG_RANGE;
165		data->tx_buf[1] = index;
166		ret = spi_write(data->spi_device, data->tx_buf,
167				sizeof(data->tx_buf));
168		if (ret < 0)
169			dev_err(&data->spi_device->dev,
170				"failed to set measurement range\n");
171		mutex_unlock(&data->lock);
172
173		return 0;
174	}
175
176	return -EINVAL;
177}
178
179static int bma220_read_avail(struct iio_dev *indio_dev,
180			     struct iio_chan_spec const *chan,
181			     const int **vals, int *type, int *length,
182			     long mask)
183{
184	switch (mask) {
185	case IIO_CHAN_INFO_SCALE:
186		*vals = (int *)bma220_scale_table;
187		*type = IIO_VAL_INT_PLUS_MICRO;
188		*length = ARRAY_SIZE(bma220_scale_table) * 2;
189		return IIO_AVAIL_LIST;
190	default:
191		return -EINVAL;
192	}
193}
194
195static const struct iio_info bma220_info = {
196	.read_raw		= bma220_read_raw,
197	.write_raw		= bma220_write_raw,
198	.read_avail		= bma220_read_avail,
199};
200
201static int bma220_init(struct spi_device *spi)
202{
203	int ret;
204
205	ret = bma220_read_reg(spi, BMA220_REG_ID);
206	if (ret != BMA220_CHIP_ID)
207		return -ENODEV;
208
209	/* Make sure the chip is powered on */
210	ret = bma220_read_reg(spi, BMA220_REG_SUSPEND);
211	if (ret == BMA220_SUSPEND_WAKE)
212		ret = bma220_read_reg(spi, BMA220_REG_SUSPEND);
213	if (ret < 0)
214		return ret;
215	if (ret == BMA220_SUSPEND_WAKE)
216		return -EBUSY;
217
218	return 0;
219}
220
221static int bma220_power(struct spi_device *spi, bool up)
222{
223	int i, ret;
224
225	/**
226	 * The chip can be suspended/woken up by a simple register read.
227	 * So, we need up to 2 register reads of the suspend register
228	 * to make sure that the device is in the desired state.
229	 */
230	for (i = 0; i < 2; i++) {
231		ret = bma220_read_reg(spi, BMA220_REG_SUSPEND);
232		if (ret < 0)
233			return ret;
234
235		if (up && ret == BMA220_SUSPEND_SLEEP)
236			return 0;
237
238		if (!up && ret == BMA220_SUSPEND_WAKE)
239			return 0;
240	}
241
242	return -EBUSY;
243}
244
245static void bma220_deinit(void *spi)
246{
247	bma220_power(spi, false);
248}
249
250static int bma220_probe(struct spi_device *spi)
251{
252	int ret;
253	struct iio_dev *indio_dev;
254	struct bma220_data *data;
255
256	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data));
257	if (!indio_dev) {
258		dev_err(&spi->dev, "iio allocation failed!\n");
259		return -ENOMEM;
260	}
261
262	data = iio_priv(indio_dev);
263	data->spi_device = spi;
264	mutex_init(&data->lock);
265
266	indio_dev->info = &bma220_info;
267	indio_dev->name = BMA220_DEVICE_NAME;
268	indio_dev->modes = INDIO_DIRECT_MODE;
269	indio_dev->channels = bma220_channels;
270	indio_dev->num_channels = ARRAY_SIZE(bma220_channels);
271	indio_dev->available_scan_masks = bma220_accel_scan_masks;
272
273	ret = bma220_init(data->spi_device);
274	if (ret)
275		return ret;
276
277	ret = devm_add_action_or_reset(&spi->dev, bma220_deinit, spi);
278	if (ret)
279		return ret;
280
281	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
282					      iio_pollfunc_store_time,
283					      bma220_trigger_handler, NULL);
284	if (ret < 0) {
285		dev_err(&spi->dev, "iio triggered buffer setup failed\n");
286		return ret;
287	}
288
289	return devm_iio_device_register(&spi->dev, indio_dev);
290}
291
292static int bma220_suspend(struct device *dev)
293{
294	struct spi_device *spi = to_spi_device(dev);
295
296	return bma220_power(spi, false);
297}
298
299static int bma220_resume(struct device *dev)
300{
301	struct spi_device *spi = to_spi_device(dev);
302
303	return bma220_power(spi, true);
304}
305static DEFINE_SIMPLE_DEV_PM_OPS(bma220_pm_ops, bma220_suspend, bma220_resume);
306
307static const struct spi_device_id bma220_spi_id[] = {
308	{"bma220", 0},
309	{}
310};
311
312static const struct acpi_device_id bma220_acpi_id[] = {
313	{"BMA0220", 0},
314	{}
315};
316MODULE_DEVICE_TABLE(spi, bma220_spi_id);
317
318static struct spi_driver bma220_driver = {
319	.driver = {
320		.name = "bma220_spi",
321		.pm = pm_sleep_ptr(&bma220_pm_ops),
322		.acpi_match_table = bma220_acpi_id,
323	},
324	.probe =            bma220_probe,
325	.id_table =         bma220_spi_id,
326};
327module_spi_driver(bma220_driver);
328
329MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
330MODULE_DESCRIPTION("BMA220 acceleration sensor driver");
331MODULE_LICENSE("GPL v2");
332