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 .driver_module = THIS_MODULE, 190 .read_raw = bma220_read_raw, 191 .write_raw = bma220_write_raw, 192 .attrs = &bma220_attribute_group, 193 }; 194 195 static int bma220_init(struct spi_device *spi) 196 { 197 int ret; 198 199 ret = bma220_read_reg(spi, BMA220_REG_ID); 200 if (ret != BMA220_CHIP_ID) 201 return -ENODEV; 202 203 /* Make sure the chip is powered on */ 204 ret = bma220_read_reg(spi, BMA220_REG_SUSPEND); 205 if (ret < 0) 206 return ret; 207 else if (ret == BMA220_SUSPEND_WAKE) 208 return bma220_read_reg(spi, BMA220_REG_SUSPEND); 209 210 return 0; 211 } 212 213 static int bma220_deinit(struct spi_device *spi) 214 { 215 int ret; 216 217 /* Make sure the chip is powered off */ 218 ret = bma220_read_reg(spi, BMA220_REG_SUSPEND); 219 if (ret < 0) 220 return ret; 221 else if (ret == BMA220_SUSPEND_SLEEP) 222 return bma220_read_reg(spi, BMA220_REG_SUSPEND); 223 224 return 0; 225 } 226 227 static int bma220_probe(struct spi_device *spi) 228 { 229 int ret; 230 struct iio_dev *indio_dev; 231 struct bma220_data *data; 232 233 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data)); 234 if (!indio_dev) { 235 dev_err(&spi->dev, "iio allocation failed!\n"); 236 return -ENOMEM; 237 } 238 239 data = iio_priv(indio_dev); 240 data->spi_device = spi; 241 spi_set_drvdata(spi, indio_dev); 242 mutex_init(&data->lock); 243 244 indio_dev->dev.parent = &spi->dev; 245 indio_dev->info = &bma220_info; 246 indio_dev->name = BMA220_DEVICE_NAME; 247 indio_dev->modes = INDIO_DIRECT_MODE; 248 indio_dev->channels = bma220_channels; 249 indio_dev->num_channels = ARRAY_SIZE(bma220_channels); 250 indio_dev->available_scan_masks = bma220_accel_scan_masks; 251 252 ret = bma220_init(data->spi_device); 253 if (ret < 0) 254 return ret; 255 256 ret = iio_triggered_buffer_setup(indio_dev, iio_pollfunc_store_time, 257 bma220_trigger_handler, NULL); 258 if (ret < 0) { 259 dev_err(&spi->dev, "iio triggered buffer setup failed\n"); 260 goto err_suspend; 261 } 262 263 ret = iio_device_register(indio_dev); 264 if (ret < 0) { 265 dev_err(&spi->dev, "iio_device_register failed\n"); 266 iio_triggered_buffer_cleanup(indio_dev); 267 goto err_suspend; 268 } 269 270 return 0; 271 272 err_suspend: 273 return bma220_deinit(spi); 274 } 275 276 static int bma220_remove(struct spi_device *spi) 277 { 278 struct iio_dev *indio_dev = spi_get_drvdata(spi); 279 280 iio_device_unregister(indio_dev); 281 iio_triggered_buffer_cleanup(indio_dev); 282 283 return bma220_deinit(spi); 284 } 285 286 #ifdef CONFIG_PM_SLEEP 287 static int bma220_suspend(struct device *dev) 288 { 289 struct bma220_data *data = 290 iio_priv(spi_get_drvdata(to_spi_device(dev))); 291 292 /* The chip can be suspended/woken up by a simple register read. */ 293 return bma220_read_reg(data->spi_device, BMA220_REG_SUSPEND); 294 } 295 296 static int bma220_resume(struct device *dev) 297 { 298 struct bma220_data *data = 299 iio_priv(spi_get_drvdata(to_spi_device(dev))); 300 301 return bma220_read_reg(data->spi_device, BMA220_REG_SUSPEND); 302 } 303 304 static SIMPLE_DEV_PM_OPS(bma220_pm_ops, bma220_suspend, bma220_resume); 305 306 #define BMA220_PM_OPS (&bma220_pm_ops) 307 #else 308 #define BMA220_PM_OPS NULL 309 #endif 310 311 static const struct spi_device_id bma220_spi_id[] = { 312 {"bma220", 0}, 313 {} 314 }; 315 316 static const struct acpi_device_id bma220_acpi_id[] = { 317 {"BMA0220", 0}, 318 {} 319 }; 320 321 MODULE_DEVICE_TABLE(spi, bma220_spi_id); 322 323 static struct spi_driver bma220_driver = { 324 .driver = { 325 .name = "bma220_spi", 326 .pm = BMA220_PM_OPS, 327 .acpi_match_table = ACPI_PTR(bma220_acpi_id), 328 }, 329 .probe = bma220_probe, 330 .remove = bma220_remove, 331 .id_table = bma220_spi_id, 332 }; 333 334 module_spi_driver(bma220_driver); 335 336 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>"); 337 MODULE_DESCRIPTION("BMA220 acceleration sensor driver"); 338 MODULE_LICENSE("GPL v2"); 339