xref: /openbmc/linux/drivers/iio/accel/bma220_spi.c (revision 93a73f6a)
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 
52 enum bma220_axis {
53 	AXIS_X,
54 	AXIS_Y,
55 	AXIS_Z,
56 };
57 
58 static const int bma220_scale_table[][2] = {
59 	{0, 623000}, {1, 248000}, {2, 491000}, {4, 983000},
60 };
61 
62 struct 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 
73 static 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 
bma220_read_reg(struct spi_device * spi,u8 reg)80 static inline int bma220_read_reg(struct spi_device *spi, u8 reg)
81 {
82 	return spi_w8r8(spi, reg | BMA220_READ_MASK);
83 }
84 
85 static const unsigned long bma220_accel_scan_masks[] = {
86 	BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
87 	0
88 };
89 
bma220_trigger_handler(int irq,void * p)90 static 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);
107 err:
108 	mutex_unlock(&data->lock);
109 	iio_trigger_notify_done(indio_dev->trig);
110 
111 	return IRQ_HANDLED;
112 }
113 
bma220_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)114 static 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 
bma220_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)143 static 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 
bma220_read_avail(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,const int ** vals,int * type,int * length,long mask)179 static 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 
195 static 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 
bma220_init(struct spi_device * spi)201 static 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 
bma220_power(struct spi_device * spi,bool up)221 static 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 
bma220_deinit(void * spi)245 static void bma220_deinit(void *spi)
246 {
247 	bma220_power(spi, false);
248 }
249 
bma220_probe(struct spi_device * spi)250 static 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 
bma220_suspend(struct device * dev)292 static 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 
bma220_resume(struct device * dev)299 static int bma220_resume(struct device *dev)
300 {
301 	struct spi_device *spi = to_spi_device(dev);
302 
303 	return bma220_power(spi, true);
304 }
305 static DEFINE_SIMPLE_DEV_PM_OPS(bma220_pm_ops, bma220_suspend, bma220_resume);
306 
307 static const struct spi_device_id bma220_spi_id[] = {
308 	{"bma220", 0},
309 	{}
310 };
311 
312 static const struct acpi_device_id bma220_acpi_id[] = {
313 	{"BMA0220", 0},
314 	{}
315 };
316 MODULE_DEVICE_TABLE(spi, bma220_spi_id);
317 
318 static 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 };
327 module_spi_driver(bma220_driver);
328 
329 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
330 MODULE_DESCRIPTION("BMA220 acceleration sensor driver");
331 MODULE_LICENSE("GPL v2");
332