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_DATA_SHIFT 2
31 #define BMA220_SUSPEND_SLEEP 0xFF
32 #define BMA220_SUSPEND_WAKE 0x00
33
34 #define BMA220_DEVICE_NAME "bma220"
35
36 #define BMA220_ACCEL_CHANNEL(index, reg, axis) { \
37 .type = IIO_ACCEL, \
38 .address = reg, \
39 .modified = 1, \
40 .channel2 = IIO_MOD_##axis, \
41 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
42 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
43 .scan_index = index, \
44 .scan_type = { \
45 .sign = 's', \
46 .realbits = 6, \
47 .storagebits = 8, \
48 .shift = BMA220_DATA_SHIFT, \
49 .endianness = IIO_CPU, \
50 }, \
51 }
52
53 enum bma220_axis {
54 AXIS_X,
55 AXIS_Y,
56 AXIS_Z,
57 };
58
59 static const int bma220_scale_table[][2] = {
60 {0, 623000}, {1, 248000}, {2, 491000}, {4, 983000},
61 };
62
63 struct bma220_data {
64 struct spi_device *spi_device;
65 struct mutex lock;
66 s8 buffer[16]; /* 3x8-bit channels + 5x8 padding + 8x8 timestamp */
67 u8 tx_buf[2] ____cacheline_aligned;
68 };
69
70 static const struct iio_chan_spec bma220_channels[] = {
71 BMA220_ACCEL_CHANNEL(0, BMA220_REG_ACCEL_X, X),
72 BMA220_ACCEL_CHANNEL(1, BMA220_REG_ACCEL_Y, Y),
73 BMA220_ACCEL_CHANNEL(2, BMA220_REG_ACCEL_Z, Z),
74 IIO_CHAN_SOFT_TIMESTAMP(3),
75 };
76
bma220_read_reg(struct spi_device * spi,u8 reg)77 static inline int bma220_read_reg(struct spi_device *spi, u8 reg)
78 {
79 return spi_w8r8(spi, reg | BMA220_READ_MASK);
80 }
81
82 static const unsigned long bma220_accel_scan_masks[] = {
83 BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
84 0
85 };
86
bma220_trigger_handler(int irq,void * p)87 static irqreturn_t bma220_trigger_handler(int irq, void *p)
88 {
89 int ret;
90 struct iio_poll_func *pf = p;
91 struct iio_dev *indio_dev = pf->indio_dev;
92 struct bma220_data *data = iio_priv(indio_dev);
93 struct spi_device *spi = data->spi_device;
94
95 mutex_lock(&data->lock);
96 data->tx_buf[0] = BMA220_REG_ACCEL_X | BMA220_READ_MASK;
97 ret = spi_write_then_read(spi, data->tx_buf, 1, data->buffer,
98 ARRAY_SIZE(bma220_channels) - 1);
99 if (ret < 0)
100 goto err;
101
102 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
103 pf->timestamp);
104 err:
105 mutex_unlock(&data->lock);
106 iio_trigger_notify_done(indio_dev->trig);
107
108 return IRQ_HANDLED;
109 }
110
bma220_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)111 static int bma220_read_raw(struct iio_dev *indio_dev,
112 struct iio_chan_spec const *chan,
113 int *val, int *val2, long mask)
114 {
115 int ret;
116 u8 range_idx;
117 struct bma220_data *data = iio_priv(indio_dev);
118
119 switch (mask) {
120 case IIO_CHAN_INFO_RAW:
121 ret = bma220_read_reg(data->spi_device, chan->address);
122 if (ret < 0)
123 return -EINVAL;
124 *val = sign_extend32(ret >> BMA220_DATA_SHIFT, 5);
125 return IIO_VAL_INT;
126 case IIO_CHAN_INFO_SCALE:
127 ret = bma220_read_reg(data->spi_device, BMA220_REG_RANGE);
128 if (ret < 0)
129 return ret;
130 range_idx = ret & BMA220_RANGE_MASK;
131 *val = bma220_scale_table[range_idx][0];
132 *val2 = bma220_scale_table[range_idx][1];
133 return IIO_VAL_INT_PLUS_MICRO;
134 }
135
136 return -EINVAL;
137 }
138
bma220_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)139 static int bma220_write_raw(struct iio_dev *indio_dev,
140 struct iio_chan_spec const *chan,
141 int val, int val2, long mask)
142 {
143 int i;
144 int ret;
145 int index = -1;
146 struct bma220_data *data = iio_priv(indio_dev);
147
148 switch (mask) {
149 case IIO_CHAN_INFO_SCALE:
150 for (i = 0; i < ARRAY_SIZE(bma220_scale_table); i++)
151 if (val == bma220_scale_table[i][0] &&
152 val2 == bma220_scale_table[i][1]) {
153 index = i;
154 break;
155 }
156 if (index < 0)
157 return -EINVAL;
158
159 mutex_lock(&data->lock);
160 data->tx_buf[0] = BMA220_REG_RANGE;
161 data->tx_buf[1] = index;
162 ret = spi_write(data->spi_device, data->tx_buf,
163 sizeof(data->tx_buf));
164 if (ret < 0)
165 dev_err(&data->spi_device->dev,
166 "failed to set measurement range\n");
167 mutex_unlock(&data->lock);
168
169 return 0;
170 }
171
172 return -EINVAL;
173 }
174
bma220_read_avail(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,const int ** vals,int * type,int * length,long mask)175 static int bma220_read_avail(struct iio_dev *indio_dev,
176 struct iio_chan_spec const *chan,
177 const int **vals, int *type, int *length,
178 long mask)
179 {
180 switch (mask) {
181 case IIO_CHAN_INFO_SCALE:
182 *vals = (int *)bma220_scale_table;
183 *type = IIO_VAL_INT_PLUS_MICRO;
184 *length = ARRAY_SIZE(bma220_scale_table) * 2;
185 return IIO_AVAIL_LIST;
186 default:
187 return -EINVAL;
188 }
189 }
190
191 static const struct iio_info bma220_info = {
192 .read_raw = bma220_read_raw,
193 .write_raw = bma220_write_raw,
194 .read_avail = bma220_read_avail,
195 };
196
bma220_init(struct spi_device * spi)197 static int bma220_init(struct spi_device *spi)
198 {
199 int ret;
200
201 ret = bma220_read_reg(spi, BMA220_REG_ID);
202 if (ret != BMA220_CHIP_ID)
203 return -ENODEV;
204
205 /* Make sure the chip is powered on */
206 ret = bma220_read_reg(spi, BMA220_REG_SUSPEND);
207 if (ret == BMA220_SUSPEND_WAKE)
208 ret = bma220_read_reg(spi, BMA220_REG_SUSPEND);
209 if (ret < 0)
210 return ret;
211 if (ret == BMA220_SUSPEND_WAKE)
212 return -EBUSY;
213
214 return 0;
215 }
216
bma220_deinit(struct spi_device * spi)217 static int bma220_deinit(struct spi_device *spi)
218 {
219 int ret;
220
221 /* Make sure the chip is powered off */
222 ret = bma220_read_reg(spi, BMA220_REG_SUSPEND);
223 if (ret == BMA220_SUSPEND_SLEEP)
224 ret = bma220_read_reg(spi, BMA220_REG_SUSPEND);
225 if (ret < 0)
226 return ret;
227 if (ret == BMA220_SUSPEND_SLEEP)
228 return -EBUSY;
229
230 return 0;
231 }
232
bma220_probe(struct spi_device * spi)233 static int bma220_probe(struct spi_device *spi)
234 {
235 int ret;
236 struct iio_dev *indio_dev;
237 struct bma220_data *data;
238
239 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data));
240 if (!indio_dev) {
241 dev_err(&spi->dev, "iio allocation failed!\n");
242 return -ENOMEM;
243 }
244
245 data = iio_priv(indio_dev);
246 data->spi_device = spi;
247 spi_set_drvdata(spi, indio_dev);
248 mutex_init(&data->lock);
249
250 indio_dev->info = &bma220_info;
251 indio_dev->name = BMA220_DEVICE_NAME;
252 indio_dev->modes = INDIO_DIRECT_MODE;
253 indio_dev->channels = bma220_channels;
254 indio_dev->num_channels = ARRAY_SIZE(bma220_channels);
255 indio_dev->available_scan_masks = bma220_accel_scan_masks;
256
257 ret = bma220_init(data->spi_device);
258 if (ret)
259 return ret;
260
261 ret = iio_triggered_buffer_setup(indio_dev, iio_pollfunc_store_time,
262 bma220_trigger_handler, NULL);
263 if (ret < 0) {
264 dev_err(&spi->dev, "iio triggered buffer setup failed\n");
265 goto err_suspend;
266 }
267
268 ret = iio_device_register(indio_dev);
269 if (ret < 0) {
270 dev_err(&spi->dev, "iio_device_register failed\n");
271 iio_triggered_buffer_cleanup(indio_dev);
272 goto err_suspend;
273 }
274
275 return 0;
276
277 err_suspend:
278 return bma220_deinit(spi);
279 }
280
bma220_remove(struct spi_device * spi)281 static int bma220_remove(struct spi_device *spi)
282 {
283 struct iio_dev *indio_dev = spi_get_drvdata(spi);
284
285 iio_device_unregister(indio_dev);
286 iio_triggered_buffer_cleanup(indio_dev);
287
288 return bma220_deinit(spi);
289 }
290
bma220_suspend(struct device * dev)291 static __maybe_unused int bma220_suspend(struct device *dev)
292 {
293 struct bma220_data *data = iio_priv(dev_get_drvdata(dev));
294
295 /* The chip can be suspended/woken up by a simple register read. */
296 return bma220_read_reg(data->spi_device, BMA220_REG_SUSPEND);
297 }
298
bma220_resume(struct device * dev)299 static __maybe_unused int bma220_resume(struct device *dev)
300 {
301 struct bma220_data *data = iio_priv(dev_get_drvdata(dev));
302
303 return bma220_read_reg(data->spi_device, BMA220_REG_SUSPEND);
304 }
305 static 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 = &bma220_pm_ops,
322 .acpi_match_table = bma220_acpi_id,
323 },
324 .probe = bma220_probe,
325 .remove = bma220_remove,
326 .id_table = bma220_spi_id,
327 };
328 module_spi_driver(bma220_driver);
329
330 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
331 MODULE_DESCRIPTION("BMA220 acceleration sensor driver");
332 MODULE_LICENSE("GPL v2");
333
