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/types.h>
13 #include <linux/spi/spi.h>
14
15 #include <linux/iio/buffer.h>
16 #include <linux/iio/iio.h>
17 #include <linux/iio/sysfs.h>
18 #include <linux/iio/trigger_consumer.h>
19 #include <linux/iio/triggered_buffer.h>
20
21 #define BMA220_REG_ID 0x00
22 #define BMA220_REG_ACCEL_X 0x02
23 #define BMA220_REG_ACCEL_Y 0x03
24 #define BMA220_REG_ACCEL_Z 0x04
25 #define BMA220_REG_RANGE 0x11
26 #define BMA220_REG_SUSPEND 0x18
27
28 #define BMA220_CHIP_ID 0xDD
29 #define BMA220_READ_MASK BIT(7)
30 #define BMA220_RANGE_MASK GENMASK(1, 0)
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 = 2, \
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 struct {
67 s8 chans[3];
68 /* Ensure timestamp is naturally aligned. */
69 aligned_s64 timestamp;
70 } scan;
71 u8 tx_buf[2] __aligned(IIO_DMA_MINALIGN);
72 };
73
74 static const struct iio_chan_spec bma220_channels[] = {
75 BMA220_ACCEL_CHANNEL(0, BMA220_REG_ACCEL_X, X),
76 BMA220_ACCEL_CHANNEL(1, BMA220_REG_ACCEL_Y, Y),
77 BMA220_ACCEL_CHANNEL(2, BMA220_REG_ACCEL_Z, Z),
78 IIO_CHAN_SOFT_TIMESTAMP(3),
79 };
80
bma220_read_reg(struct spi_device * spi,u8 reg)81 static inline int bma220_read_reg(struct spi_device *spi, u8 reg)
82 {
83 return spi_w8r8(spi, reg | BMA220_READ_MASK);
84 }
85
86 static const unsigned long bma220_accel_scan_masks[] = {
87 BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
88 0
89 };
90
bma220_trigger_handler(int irq,void * p)91 static irqreturn_t bma220_trigger_handler(int irq, void *p)
92 {
93 int ret;
94 struct iio_poll_func *pf = p;
95 struct iio_dev *indio_dev = pf->indio_dev;
96 struct bma220_data *data = iio_priv(indio_dev);
97 struct spi_device *spi = data->spi_device;
98
99 mutex_lock(&data->lock);
100 data->tx_buf[0] = BMA220_REG_ACCEL_X | BMA220_READ_MASK;
101 ret = spi_write_then_read(spi, data->tx_buf, 1, &data->scan.chans,
102 ARRAY_SIZE(bma220_channels) - 1);
103 if (ret < 0)
104 goto err;
105
106 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
107 pf->timestamp);
108 err:
109 mutex_unlock(&data->lock);
110 iio_trigger_notify_done(indio_dev->trig);
111
112 return IRQ_HANDLED;
113 }
114
bma220_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)115 static int bma220_read_raw(struct iio_dev *indio_dev,
116 struct iio_chan_spec const *chan,
117 int *val, int *val2, long mask)
118 {
119 int ret;
120 u8 range_idx;
121 struct bma220_data *data = iio_priv(indio_dev);
122
123 switch (mask) {
124 case IIO_CHAN_INFO_RAW:
125 ret = bma220_read_reg(data->spi_device, chan->address);
126 if (ret < 0)
127 return -EINVAL;
128 *val = sign_extend32(ret >> chan->scan_type.shift,
129 chan->scan_type.realbits - 1);
130 return IIO_VAL_INT;
131 case IIO_CHAN_INFO_SCALE:
132 ret = bma220_read_reg(data->spi_device, BMA220_REG_RANGE);
133 if (ret < 0)
134 return ret;
135 range_idx = ret & BMA220_RANGE_MASK;
136 *val = bma220_scale_table[range_idx][0];
137 *val2 = bma220_scale_table[range_idx][1];
138 return IIO_VAL_INT_PLUS_MICRO;
139 }
140
141 return -EINVAL;
142 }
143
bma220_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)144 static int bma220_write_raw(struct iio_dev *indio_dev,
145 struct iio_chan_spec const *chan,
146 int val, int val2, long mask)
147 {
148 int i;
149 int ret;
150 int index = -1;
151 struct bma220_data *data = iio_priv(indio_dev);
152
153 switch (mask) {
154 case IIO_CHAN_INFO_SCALE:
155 for (i = 0; i < ARRAY_SIZE(bma220_scale_table); i++)
156 if (val == bma220_scale_table[i][0] &&
157 val2 == bma220_scale_table[i][1]) {
158 index = i;
159 break;
160 }
161 if (index < 0)
162 return -EINVAL;
163
164 mutex_lock(&data->lock);
165 data->tx_buf[0] = BMA220_REG_RANGE;
166 data->tx_buf[1] = index;
167 ret = spi_write(data->spi_device, data->tx_buf,
168 sizeof(data->tx_buf));
169 if (ret < 0)
170 dev_err(&data->spi_device->dev,
171 "failed to set measurement range\n");
172 mutex_unlock(&data->lock);
173
174 return 0;
175 }
176
177 return -EINVAL;
178 }
179
bma220_read_avail(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,const int ** vals,int * type,int * length,long mask)180 static int bma220_read_avail(struct iio_dev *indio_dev,
181 struct iio_chan_spec const *chan,
182 const int **vals, int *type, int *length,
183 long mask)
184 {
185 switch (mask) {
186 case IIO_CHAN_INFO_SCALE:
187 *vals = (int *)bma220_scale_table;
188 *type = IIO_VAL_INT_PLUS_MICRO;
189 *length = ARRAY_SIZE(bma220_scale_table) * 2;
190 return IIO_AVAIL_LIST;
191 default:
192 return -EINVAL;
193 }
194 }
195
196 static const struct iio_info bma220_info = {
197 .read_raw = bma220_read_raw,
198 .write_raw = bma220_write_raw,
199 .read_avail = bma220_read_avail,
200 };
201
bma220_init(struct spi_device * spi)202 static int bma220_init(struct spi_device *spi)
203 {
204 int ret;
205
206 ret = bma220_read_reg(spi, BMA220_REG_ID);
207 if (ret != BMA220_CHIP_ID)
208 return -ENODEV;
209
210 /* Make sure the chip is powered on */
211 ret = bma220_read_reg(spi, BMA220_REG_SUSPEND);
212 if (ret == BMA220_SUSPEND_WAKE)
213 ret = bma220_read_reg(spi, BMA220_REG_SUSPEND);
214 if (ret < 0)
215 return ret;
216 if (ret == BMA220_SUSPEND_WAKE)
217 return -EBUSY;
218
219 return 0;
220 }
221
bma220_power(struct spi_device * spi,bool up)222 static int bma220_power(struct spi_device *spi, bool up)
223 {
224 int i, ret;
225
226 /**
227 * The chip can be suspended/woken up by a simple register read.
228 * So, we need up to 2 register reads of the suspend register
229 * to make sure that the device is in the desired state.
230 */
231 for (i = 0; i < 2; i++) {
232 ret = bma220_read_reg(spi, BMA220_REG_SUSPEND);
233 if (ret < 0)
234 return ret;
235
236 if (up && ret == BMA220_SUSPEND_SLEEP)
237 return 0;
238
239 if (!up && ret == BMA220_SUSPEND_WAKE)
240 return 0;
241 }
242
243 return -EBUSY;
244 }
245
bma220_deinit(void * spi)246 static void bma220_deinit(void *spi)
247 {
248 bma220_power(spi, false);
249 }
250
bma220_probe(struct spi_device * spi)251 static int bma220_probe(struct spi_device *spi)
252 {
253 int ret;
254 struct iio_dev *indio_dev;
255 struct bma220_data *data;
256
257 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data));
258 if (!indio_dev) {
259 dev_err(&spi->dev, "iio allocation failed!\n");
260 return -ENOMEM;
261 }
262
263 data = iio_priv(indio_dev);
264 data->spi_device = spi;
265 mutex_init(&data->lock);
266
267 indio_dev->info = &bma220_info;
268 indio_dev->name = BMA220_DEVICE_NAME;
269 indio_dev->modes = INDIO_DIRECT_MODE;
270 indio_dev->channels = bma220_channels;
271 indio_dev->num_channels = ARRAY_SIZE(bma220_channels);
272 indio_dev->available_scan_masks = bma220_accel_scan_masks;
273
274 ret = bma220_init(data->spi_device);
275 if (ret)
276 return ret;
277
278 ret = devm_add_action_or_reset(&spi->dev, bma220_deinit, spi);
279 if (ret)
280 return ret;
281
282 ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
283 iio_pollfunc_store_time,
284 bma220_trigger_handler, NULL);
285 if (ret < 0) {
286 dev_err(&spi->dev, "iio triggered buffer setup failed\n");
287 return ret;
288 }
289
290 return devm_iio_device_register(&spi->dev, indio_dev);
291 }
292
bma220_suspend(struct device * dev)293 static int bma220_suspend(struct device *dev)
294 {
295 struct spi_device *spi = to_spi_device(dev);
296
297 return bma220_power(spi, false);
298 }
299
bma220_resume(struct device * dev)300 static int bma220_resume(struct device *dev)
301 {
302 struct spi_device *spi = to_spi_device(dev);
303
304 return bma220_power(spi, true);
305 }
306 static DEFINE_SIMPLE_DEV_PM_OPS(bma220_pm_ops, bma220_suspend, bma220_resume);
307
308 static const struct spi_device_id bma220_spi_id[] = {
309 {"bma220", 0},
310 {}
311 };
312
313 static const struct acpi_device_id bma220_acpi_id[] = {
314 {"BMA0220", 0},
315 {}
316 };
317 MODULE_DEVICE_TABLE(spi, bma220_spi_id);
318
319 static struct spi_driver bma220_driver = {
320 .driver = {
321 .name = "bma220_spi",
322 .pm = pm_sleep_ptr(&bma220_pm_ops),
323 .acpi_match_table = bma220_acpi_id,
324 },
325 .probe = bma220_probe,
326 .id_table = bma220_spi_id,
327 };
328 module_spi_driver(bma220_driver);
329
330 MODULE_AUTHOR("Tiberiu Breana <[email protected]>");
331 MODULE_DESCRIPTION("BMA220 acceleration sensor driver");
332 MODULE_LICENSE("GPL v2");
333