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