1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * mpl3115.c - Support for Freescale MPL3115A2 pressure/temperature sensor 4 * 5 * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net> 6 * 7 * (7-bit I2C slave address 0x60) 8 * 9 * TODO: FIFO buffer, altimeter mode, oversampling, continuous mode, 10 * interrupts, user offset correction, raw mode 11 */ 12 13 #include <linux/module.h> 14 #include <linux/i2c.h> 15 #include <linux/iio/iio.h> 16 #include <linux/iio/sysfs.h> 17 #include <linux/iio/trigger_consumer.h> 18 #include <linux/iio/buffer.h> 19 #include <linux/iio/triggered_buffer.h> 20 #include <linux/delay.h> 21 22 #define MPL3115_STATUS 0x00 23 #define MPL3115_OUT_PRESS 0x01 /* MSB first, 20 bit */ 24 #define MPL3115_OUT_TEMP 0x04 /* MSB first, 12 bit */ 25 #define MPL3115_WHO_AM_I 0x0c 26 #define MPL3115_CTRL_REG1 0x26 27 28 #define MPL3115_DEVICE_ID 0xc4 29 30 #define MPL3115_STATUS_PRESS_RDY BIT(2) 31 #define MPL3115_STATUS_TEMP_RDY BIT(1) 32 33 #define MPL3115_CTRL_RESET BIT(2) /* software reset */ 34 #define MPL3115_CTRL_OST BIT(1) /* initiate measurement */ 35 #define MPL3115_CTRL_ACTIVE BIT(0) /* continuous measurement */ 36 #define MPL3115_CTRL_OS_258MS (BIT(5) | BIT(4)) /* 64x oversampling */ 37 38 struct mpl3115_data { 39 struct i2c_client *client; 40 struct mutex lock; 41 u8 ctrl_reg1; 42 }; 43 44 static int mpl3115_request(struct mpl3115_data *data) 45 { 46 int ret, tries = 15; 47 48 /* trigger measurement */ 49 ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1, 50 data->ctrl_reg1 | MPL3115_CTRL_OST); 51 if (ret < 0) 52 return ret; 53 54 while (tries-- > 0) { 55 ret = i2c_smbus_read_byte_data(data->client, MPL3115_CTRL_REG1); 56 if (ret < 0) 57 return ret; 58 /* wait for data ready, i.e. OST cleared */ 59 if (!(ret & MPL3115_CTRL_OST)) 60 break; 61 msleep(20); 62 } 63 64 if (tries < 0) { 65 dev_err(&data->client->dev, "data not ready\n"); 66 return -EIO; 67 } 68 69 return 0; 70 } 71 72 static int mpl3115_read_raw(struct iio_dev *indio_dev, 73 struct iio_chan_spec const *chan, 74 int *val, int *val2, long mask) 75 { 76 struct mpl3115_data *data = iio_priv(indio_dev); 77 int ret; 78 79 switch (mask) { 80 case IIO_CHAN_INFO_RAW: 81 ret = iio_device_claim_direct_mode(indio_dev); 82 if (ret) 83 return ret; 84 85 switch (chan->type) { 86 case IIO_PRESSURE: { /* in 0.25 pascal / LSB */ 87 __be32 tmp = 0; 88 89 mutex_lock(&data->lock); 90 ret = mpl3115_request(data); 91 if (ret < 0) { 92 mutex_unlock(&data->lock); 93 break; 94 } 95 ret = i2c_smbus_read_i2c_block_data(data->client, 96 MPL3115_OUT_PRESS, 3, (u8 *) &tmp); 97 mutex_unlock(&data->lock); 98 if (ret < 0) 99 break; 100 *val = be32_to_cpu(tmp) >> chan->scan_type.shift; 101 ret = IIO_VAL_INT; 102 break; 103 } 104 case IIO_TEMP: { /* in 0.0625 celsius / LSB */ 105 __be16 tmp; 106 107 mutex_lock(&data->lock); 108 ret = mpl3115_request(data); 109 if (ret < 0) { 110 mutex_unlock(&data->lock); 111 break; 112 } 113 ret = i2c_smbus_read_i2c_block_data(data->client, 114 MPL3115_OUT_TEMP, 2, (u8 *) &tmp); 115 mutex_unlock(&data->lock); 116 if (ret < 0) 117 break; 118 *val = sign_extend32(be16_to_cpu(tmp) >> chan->scan_type.shift, 119 chan->scan_type.realbits - 1); 120 ret = IIO_VAL_INT; 121 break; 122 } 123 default: 124 ret = -EINVAL; 125 break; 126 } 127 128 iio_device_release_direct_mode(indio_dev); 129 return ret; 130 131 case IIO_CHAN_INFO_SCALE: 132 switch (chan->type) { 133 case IIO_PRESSURE: 134 *val = 0; 135 *val2 = 250; /* want kilopascal */ 136 return IIO_VAL_INT_PLUS_MICRO; 137 case IIO_TEMP: 138 *val = 0; 139 *val2 = 62500; 140 return IIO_VAL_INT_PLUS_MICRO; 141 default: 142 return -EINVAL; 143 } 144 } 145 return -EINVAL; 146 } 147 148 static irqreturn_t mpl3115_trigger_handler(int irq, void *p) 149 { 150 struct iio_poll_func *pf = p; 151 struct iio_dev *indio_dev = pf->indio_dev; 152 struct mpl3115_data *data = iio_priv(indio_dev); 153 /* 154 * 32-bit channel + 16-bit channel + padding + ts 155 * Note that it is possible for only one of the first 2 156 * channels to be enabled. If that happens, the first element 157 * of the buffer may be either 16 or 32-bits. As such we cannot 158 * use a simple structure definition to express this data layout. 159 */ 160 u8 buffer[16] __aligned(8); 161 int ret, pos = 0; 162 163 mutex_lock(&data->lock); 164 ret = mpl3115_request(data); 165 if (ret < 0) { 166 mutex_unlock(&data->lock); 167 goto done; 168 } 169 170 memset(buffer, 0, sizeof(buffer)); 171 if (test_bit(0, indio_dev->active_scan_mask)) { 172 ret = i2c_smbus_read_i2c_block_data(data->client, 173 MPL3115_OUT_PRESS, 3, &buffer[pos]); 174 if (ret < 0) { 175 mutex_unlock(&data->lock); 176 goto done; 177 } 178 pos += 4; 179 } 180 181 if (test_bit(1, indio_dev->active_scan_mask)) { 182 ret = i2c_smbus_read_i2c_block_data(data->client, 183 MPL3115_OUT_TEMP, 2, &buffer[pos]); 184 if (ret < 0) { 185 mutex_unlock(&data->lock); 186 goto done; 187 } 188 } 189 mutex_unlock(&data->lock); 190 191 iio_push_to_buffers_with_timestamp(indio_dev, buffer, 192 iio_get_time_ns(indio_dev)); 193 194 done: 195 iio_trigger_notify_done(indio_dev->trig); 196 return IRQ_HANDLED; 197 } 198 199 static const struct iio_chan_spec mpl3115_channels[] = { 200 { 201 .type = IIO_PRESSURE, 202 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 203 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), 204 .scan_index = 0, 205 .scan_type = { 206 .sign = 'u', 207 .realbits = 20, 208 .storagebits = 32, 209 .shift = 12, 210 .endianness = IIO_BE, 211 } 212 }, 213 { 214 .type = IIO_TEMP, 215 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), 216 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), 217 .scan_index = 1, 218 .scan_type = { 219 .sign = 's', 220 .realbits = 12, 221 .storagebits = 16, 222 .shift = 4, 223 .endianness = IIO_BE, 224 } 225 }, 226 IIO_CHAN_SOFT_TIMESTAMP(2), 227 }; 228 229 static const struct iio_info mpl3115_info = { 230 .read_raw = &mpl3115_read_raw, 231 }; 232 233 static int mpl3115_probe(struct i2c_client *client) 234 { 235 const struct i2c_device_id *id = i2c_client_get_device_id(client); 236 struct mpl3115_data *data; 237 struct iio_dev *indio_dev; 238 int ret; 239 240 ret = i2c_smbus_read_byte_data(client, MPL3115_WHO_AM_I); 241 if (ret < 0) 242 return ret; 243 if (ret != MPL3115_DEVICE_ID) 244 return -ENODEV; 245 246 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 247 if (!indio_dev) 248 return -ENOMEM; 249 250 data = iio_priv(indio_dev); 251 data->client = client; 252 mutex_init(&data->lock); 253 254 i2c_set_clientdata(client, indio_dev); 255 indio_dev->info = &mpl3115_info; 256 indio_dev->name = id->name; 257 indio_dev->modes = INDIO_DIRECT_MODE; 258 indio_dev->channels = mpl3115_channels; 259 indio_dev->num_channels = ARRAY_SIZE(mpl3115_channels); 260 261 /* software reset, I2C transfer is aborted (fails) */ 262 i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1, 263 MPL3115_CTRL_RESET); 264 msleep(50); 265 266 data->ctrl_reg1 = MPL3115_CTRL_OS_258MS; 267 ret = i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1, 268 data->ctrl_reg1); 269 if (ret < 0) 270 return ret; 271 272 ret = iio_triggered_buffer_setup(indio_dev, NULL, 273 mpl3115_trigger_handler, NULL); 274 if (ret < 0) 275 return ret; 276 277 ret = iio_device_register(indio_dev); 278 if (ret < 0) 279 goto buffer_cleanup; 280 return 0; 281 282 buffer_cleanup: 283 iio_triggered_buffer_cleanup(indio_dev); 284 return ret; 285 } 286 287 static int mpl3115_standby(struct mpl3115_data *data) 288 { 289 return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1, 290 data->ctrl_reg1 & ~MPL3115_CTRL_ACTIVE); 291 } 292 293 static void mpl3115_remove(struct i2c_client *client) 294 { 295 struct iio_dev *indio_dev = i2c_get_clientdata(client); 296 297 iio_device_unregister(indio_dev); 298 iio_triggered_buffer_cleanup(indio_dev); 299 mpl3115_standby(iio_priv(indio_dev)); 300 } 301 302 static int mpl3115_suspend(struct device *dev) 303 { 304 return mpl3115_standby(iio_priv(i2c_get_clientdata( 305 to_i2c_client(dev)))); 306 } 307 308 static int mpl3115_resume(struct device *dev) 309 { 310 struct mpl3115_data *data = iio_priv(i2c_get_clientdata( 311 to_i2c_client(dev))); 312 313 return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1, 314 data->ctrl_reg1); 315 } 316 317 static DEFINE_SIMPLE_DEV_PM_OPS(mpl3115_pm_ops, mpl3115_suspend, 318 mpl3115_resume); 319 320 static const struct i2c_device_id mpl3115_id[] = { 321 { "mpl3115", 0 }, 322 { } 323 }; 324 MODULE_DEVICE_TABLE(i2c, mpl3115_id); 325 326 static const struct of_device_id mpl3115_of_match[] = { 327 { .compatible = "fsl,mpl3115" }, 328 { } 329 }; 330 MODULE_DEVICE_TABLE(of, mpl3115_of_match); 331 332 static struct i2c_driver mpl3115_driver = { 333 .driver = { 334 .name = "mpl3115", 335 .of_match_table = mpl3115_of_match, 336 .pm = pm_sleep_ptr(&mpl3115_pm_ops), 337 }, 338 .probe_new = mpl3115_probe, 339 .remove = mpl3115_remove, 340 .id_table = mpl3115_id, 341 }; 342 module_i2c_driver(mpl3115_driver); 343 344 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>"); 345 MODULE_DESCRIPTION("Freescale MPL3115 pressure/temperature driver"); 346 MODULE_LICENSE("GPL"); 347