1 /** 2 * BMA220 Digital triaxial acceleration sensor driver 3 * 4 * Copyright (c) 2016, Intel Corporation. 5 * 6 * This file is subject to the terms and conditions of version 2 of 7 * the GNU General Public License. See the file COPYING in the main 8 * directory of this archive for more details. 9 */ 10 11 #include <linux/acpi.h> 12 #include <linux/kernel.h> 13 #include <linux/module.h> 14 #include <linux/iio/buffer.h> 15 #include <linux/iio/iio.h> 16 #include <linux/iio/sysfs.h> 17 #include <linux/spi/spi.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 0x80 30 #define BMA220_RANGE_MASK 0x03 31 #define BMA220_DATA_SHIFT 2 32 #define BMA220_SUSPEND_SLEEP 0xFF 33 #define BMA220_SUSPEND_WAKE 0x00 34 35 #define BMA220_DEVICE_NAME "bma220" 36 #define BMA220_SCALE_AVAILABLE "0.623 1.248 2.491 4.983" 37 38 #define BMA220_ACCEL_CHANNEL(index, reg, axis) { \ 39 .type = IIO_ACCEL, \ 40 .address = reg, \ 41 .modified = 1, \ 42 .channel2 = IIO_MOD_##axis, \ 43 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 44 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 45 .scan_index = index, \ 46 .scan_type = { \ 47 .sign = 's', \ 48 .realbits = 6, \ 49 .storagebits = 8, \ 50 .shift = BMA220_DATA_SHIFT, \ 51 .endianness = IIO_CPU, \ 52 }, \ 53 } 54 55 enum bma220_axis { 56 AXIS_X, 57 AXIS_Y, 58 AXIS_Z, 59 }; 60 61 static IIO_CONST_ATTR(in_accel_scale_available, BMA220_SCALE_AVAILABLE); 62 63 static struct attribute *bma220_attributes[] = { 64 &iio_const_attr_in_accel_scale_available.dev_attr.attr, 65 NULL, 66 }; 67 68 static const struct attribute_group bma220_attribute_group = { 69 .attrs = bma220_attributes, 70 }; 71 72 static const int bma220_scale_table[][4] = { 73 {0, 623000}, {1, 248000}, {2, 491000}, {4, 983000} 74 }; 75 76 struct bma220_data { 77 struct spi_device *spi_device; 78 struct mutex lock; 79 s8 buffer[16]; /* 3x8-bit channels + 5x8 padding + 8x8 timestamp */ 80 u8 tx_buf[2] ____cacheline_aligned; 81 }; 82 83 static const struct iio_chan_spec bma220_channels[] = { 84 BMA220_ACCEL_CHANNEL(0, BMA220_REG_ACCEL_X, X), 85 BMA220_ACCEL_CHANNEL(1, BMA220_REG_ACCEL_Y, Y), 86 BMA220_ACCEL_CHANNEL(2, BMA220_REG_ACCEL_Z, Z), 87 IIO_CHAN_SOFT_TIMESTAMP(3), 88 }; 89 90 static inline int bma220_read_reg(struct spi_device *spi, u8 reg) 91 { 92 return spi_w8r8(spi, reg | BMA220_READ_MASK); 93 } 94 95 static const unsigned long bma220_accel_scan_masks[] = { 96 BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z), 97 0 98 }; 99 100 static irqreturn_t bma220_trigger_handler(int irq, void *p) 101 { 102 int ret; 103 struct iio_poll_func *pf = p; 104 struct iio_dev *indio_dev = pf->indio_dev; 105 struct bma220_data *data = iio_priv(indio_dev); 106 struct spi_device *spi = data->spi_device; 107 108 mutex_lock(&data->lock); 109 data->tx_buf[0] = BMA220_REG_ACCEL_X | BMA220_READ_MASK; 110 ret = spi_write_then_read(spi, data->tx_buf, 1, data->buffer, 111 ARRAY_SIZE(bma220_channels) - 1); 112 if (ret < 0) 113 goto err; 114 115 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, 116 pf->timestamp); 117 err: 118 mutex_unlock(&data->lock); 119 iio_trigger_notify_done(indio_dev->trig); 120 121 return IRQ_HANDLED; 122 } 123 124 static int bma220_read_raw(struct iio_dev *indio_dev, 125 struct iio_chan_spec const *chan, 126 int *val, int *val2, long mask) 127 { 128 int ret; 129 u8 range_idx; 130 struct bma220_data *data = iio_priv(indio_dev); 131 132 switch (mask) { 133 case IIO_CHAN_INFO_RAW: 134 ret = bma220_read_reg(data->spi_device, chan->address); 135 if (ret < 0) 136 return -EINVAL; 137 *val = sign_extend32(ret >> BMA220_DATA_SHIFT, 5); 138 return IIO_VAL_INT; 139 case IIO_CHAN_INFO_SCALE: 140 ret = bma220_read_reg(data->spi_device, BMA220_REG_RANGE); 141 if (ret < 0) 142 return ret; 143 range_idx = ret & BMA220_RANGE_MASK; 144 *val = bma220_scale_table[range_idx][0]; 145 *val2 = bma220_scale_table[range_idx][1]; 146 return IIO_VAL_INT_PLUS_MICRO; 147 } 148 149 return -EINVAL; 150 } 151 152 static int bma220_write_raw(struct iio_dev *indio_dev, 153 struct iio_chan_spec const *chan, 154 int val, int val2, long mask) 155 { 156 int i; 157 int ret; 158 int index = -1; 159 struct bma220_data *data = iio_priv(indio_dev); 160 161 switch (mask) { 162 case IIO_CHAN_INFO_SCALE: 163 for (i = 0; i < ARRAY_SIZE(bma220_scale_table); i++) 164 if (val == bma220_scale_table[i][0] && 165 val2 == bma220_scale_table[i][1]) { 166 index = i; 167 break; 168 } 169 if (index < 0) 170 return -EINVAL; 171 172 mutex_lock(&data->lock); 173 data->tx_buf[0] = BMA220_REG_RANGE; 174 data->tx_buf[1] = index; 175 ret = spi_write(data->spi_device, data->tx_buf, 176 sizeof(data->tx_buf)); 177 if (ret < 0) 178 dev_err(&data->spi_device->dev, 179 "failed to set measurement range\n"); 180 mutex_unlock(&data->lock); 181 182 return 0; 183 } 184 185 return -EINVAL; 186 } 187 188 static const struct iio_info bma220_info = { 189 .read_raw = bma220_read_raw, 190 .write_raw = bma220_write_raw, 191 .attrs = &bma220_attribute_group, 192 }; 193 194 static int bma220_init(struct spi_device *spi) 195 { 196 int ret; 197 198 ret = bma220_read_reg(spi, BMA220_REG_ID); 199 if (ret != BMA220_CHIP_ID) 200 return -ENODEV; 201 202 /* Make sure the chip is powered on */ 203 ret = bma220_read_reg(spi, BMA220_REG_SUSPEND); 204 if (ret < 0) 205 return ret; 206 else if (ret == BMA220_SUSPEND_WAKE) 207 return bma220_read_reg(spi, BMA220_REG_SUSPEND); 208 209 return 0; 210 } 211 212 static int bma220_deinit(struct spi_device *spi) 213 { 214 int ret; 215 216 /* Make sure the chip is powered off */ 217 ret = bma220_read_reg(spi, BMA220_REG_SUSPEND); 218 if (ret < 0) 219 return ret; 220 else if (ret == BMA220_SUSPEND_SLEEP) 221 return bma220_read_reg(spi, BMA220_REG_SUSPEND); 222 223 return 0; 224 } 225 226 static int bma220_probe(struct spi_device *spi) 227 { 228 int ret; 229 struct iio_dev *indio_dev; 230 struct bma220_data *data; 231 232 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data)); 233 if (!indio_dev) { 234 dev_err(&spi->dev, "iio allocation failed!\n"); 235 return -ENOMEM; 236 } 237 238 data = iio_priv(indio_dev); 239 data->spi_device = spi; 240 spi_set_drvdata(spi, indio_dev); 241 mutex_init(&data->lock); 242 243 indio_dev->dev.parent = &spi->dev; 244 indio_dev->info = &bma220_info; 245 indio_dev->name = BMA220_DEVICE_NAME; 246 indio_dev->modes = INDIO_DIRECT_MODE; 247 indio_dev->channels = bma220_channels; 248 indio_dev->num_channels = ARRAY_SIZE(bma220_channels); 249 indio_dev->available_scan_masks = bma220_accel_scan_masks; 250 251 ret = bma220_init(data->spi_device); 252 if (ret < 0) 253 return ret; 254 255 ret = iio_triggered_buffer_setup(indio_dev, iio_pollfunc_store_time, 256 bma220_trigger_handler, NULL); 257 if (ret < 0) { 258 dev_err(&spi->dev, "iio triggered buffer setup failed\n"); 259 goto err_suspend; 260 } 261 262 ret = iio_device_register(indio_dev); 263 if (ret < 0) { 264 dev_err(&spi->dev, "iio_device_register failed\n"); 265 iio_triggered_buffer_cleanup(indio_dev); 266 goto err_suspend; 267 } 268 269 return 0; 270 271 err_suspend: 272 return bma220_deinit(spi); 273 } 274 275 static int bma220_remove(struct spi_device *spi) 276 { 277 struct iio_dev *indio_dev = spi_get_drvdata(spi); 278 279 iio_device_unregister(indio_dev); 280 iio_triggered_buffer_cleanup(indio_dev); 281 282 return bma220_deinit(spi); 283 } 284 285 #ifdef CONFIG_PM_SLEEP 286 static int bma220_suspend(struct device *dev) 287 { 288 struct bma220_data *data = 289 iio_priv(spi_get_drvdata(to_spi_device(dev))); 290 291 /* The chip can be suspended/woken up by a simple register read. */ 292 return bma220_read_reg(data->spi_device, BMA220_REG_SUSPEND); 293 } 294 295 static int bma220_resume(struct device *dev) 296 { 297 struct bma220_data *data = 298 iio_priv(spi_get_drvdata(to_spi_device(dev))); 299 300 return bma220_read_reg(data->spi_device, BMA220_REG_SUSPEND); 301 } 302 303 static SIMPLE_DEV_PM_OPS(bma220_pm_ops, bma220_suspend, bma220_resume); 304 305 #define BMA220_PM_OPS (&bma220_pm_ops) 306 #else 307 #define BMA220_PM_OPS NULL 308 #endif 309 310 static const struct spi_device_id bma220_spi_id[] = { 311 {"bma220", 0}, 312 {} 313 }; 314 315 static const struct acpi_device_id bma220_acpi_id[] = { 316 {"BMA0220", 0}, 317 {} 318 }; 319 320 MODULE_DEVICE_TABLE(spi, bma220_spi_id); 321 322 static struct spi_driver bma220_driver = { 323 .driver = { 324 .name = "bma220_spi", 325 .pm = BMA220_PM_OPS, 326 .acpi_match_table = ACPI_PTR(bma220_acpi_id), 327 }, 328 .probe = bma220_probe, 329 .remove = bma220_remove, 330 .id_table = bma220_spi_id, 331 }; 332 333 module_spi_driver(bma220_driver); 334 335 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>"); 336 MODULE_DESCRIPTION("BMA220 acceleration sensor driver"); 337 MODULE_LICENSE("GPL v2"); 338