1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * IIO accel core driver for Freescale MMA7455L 3-axis 10-bit accelerometer 4 * Copyright 2015 Joachim Eastwood <manabian@gmail.com> 5 * 6 * UNSUPPORTED hardware features: 7 * - 8-bit mode with different scales 8 * - INT1/INT2 interrupts 9 * - Offset calibration 10 * - Events 11 */ 12 13 #include <linux/delay.h> 14 #include <linux/iio/iio.h> 15 #include <linux/iio/sysfs.h> 16 #include <linux/iio/buffer.h> 17 #include <linux/iio/trigger.h> 18 #include <linux/iio/trigger_consumer.h> 19 #include <linux/iio/triggered_buffer.h> 20 #include <linux/module.h> 21 #include <linux/regmap.h> 22 23 #include "mma7455.h" 24 25 #define MMA7455_REG_XOUTL 0x00 26 #define MMA7455_REG_XOUTH 0x01 27 #define MMA7455_REG_YOUTL 0x02 28 #define MMA7455_REG_YOUTH 0x03 29 #define MMA7455_REG_ZOUTL 0x04 30 #define MMA7455_REG_ZOUTH 0x05 31 #define MMA7455_REG_STATUS 0x09 32 #define MMA7455_STATUS_DRDY BIT(0) 33 #define MMA7455_REG_WHOAMI 0x0f 34 #define MMA7455_WHOAMI_ID 0x55 35 #define MMA7455_REG_MCTL 0x16 36 #define MMA7455_MCTL_MODE_STANDBY 0x00 37 #define MMA7455_MCTL_MODE_MEASURE 0x01 38 #define MMA7455_REG_CTL1 0x18 39 #define MMA7455_CTL1_DFBW_MASK BIT(7) 40 #define MMA7455_CTL1_DFBW_125HZ BIT(7) 41 #define MMA7455_CTL1_DFBW_62_5HZ 0 42 #define MMA7455_REG_TW 0x1e 43 44 /* 45 * When MMA7455 is used in 10-bit it has a fullscale of -8g 46 * corresponding to raw value -512. The userspace interface 47 * uses m/s^2 and we declare micro units. 48 * So scale factor is given by: 49 * g * 8 * 1e6 / 512 = 153228.90625, with g = 9.80665 50 */ 51 #define MMA7455_10BIT_SCALE 153229 52 53 struct mma7455_data { 54 struct regmap *regmap; 55 /* 56 * Used to reorganize data. Will ensure correct alignment of 57 * the timestamp if present 58 */ 59 struct { 60 __le16 channels[3]; 61 s64 ts __aligned(8); 62 } scan; 63 }; 64 65 static int mma7455_drdy(struct mma7455_data *mma7455) 66 { 67 struct device *dev = regmap_get_device(mma7455->regmap); 68 unsigned int reg; 69 int tries = 3; 70 int ret; 71 72 while (tries-- > 0) { 73 ret = regmap_read(mma7455->regmap, MMA7455_REG_STATUS, ®); 74 if (ret) 75 return ret; 76 77 if (reg & MMA7455_STATUS_DRDY) 78 return 0; 79 80 msleep(20); 81 } 82 83 dev_warn(dev, "data not ready\n"); 84 85 return -EIO; 86 } 87 88 static irqreturn_t mma7455_trigger_handler(int irq, void *p) 89 { 90 struct iio_poll_func *pf = p; 91 struct iio_dev *indio_dev = pf->indio_dev; 92 struct mma7455_data *mma7455 = iio_priv(indio_dev); 93 int ret; 94 95 ret = mma7455_drdy(mma7455); 96 if (ret) 97 goto done; 98 99 ret = regmap_bulk_read(mma7455->regmap, MMA7455_REG_XOUTL, 100 mma7455->scan.channels, 101 sizeof(mma7455->scan.channels)); 102 if (ret) 103 goto done; 104 105 iio_push_to_buffers_with_timestamp(indio_dev, &mma7455->scan, 106 iio_get_time_ns(indio_dev)); 107 108 done: 109 iio_trigger_notify_done(indio_dev->trig); 110 111 return IRQ_HANDLED; 112 } 113 114 static int mma7455_read_raw(struct iio_dev *indio_dev, 115 struct iio_chan_spec const *chan, 116 int *val, int *val2, long mask) 117 { 118 struct mma7455_data *mma7455 = iio_priv(indio_dev); 119 unsigned int reg; 120 __le16 data; 121 int ret; 122 123 switch (mask) { 124 case IIO_CHAN_INFO_RAW: 125 if (iio_buffer_enabled(indio_dev)) 126 return -EBUSY; 127 128 ret = mma7455_drdy(mma7455); 129 if (ret) 130 return ret; 131 132 ret = regmap_bulk_read(mma7455->regmap, chan->address, &data, 133 sizeof(data)); 134 if (ret) 135 return ret; 136 137 *val = sign_extend32(le16_to_cpu(data), 138 chan->scan_type.realbits - 1); 139 140 return IIO_VAL_INT; 141 142 case IIO_CHAN_INFO_SCALE: 143 *val = 0; 144 *val2 = MMA7455_10BIT_SCALE; 145 146 return IIO_VAL_INT_PLUS_MICRO; 147 148 case IIO_CHAN_INFO_SAMP_FREQ: 149 ret = regmap_read(mma7455->regmap, MMA7455_REG_CTL1, ®); 150 if (ret) 151 return ret; 152 153 if (reg & MMA7455_CTL1_DFBW_MASK) 154 *val = 250; 155 else 156 *val = 125; 157 158 return IIO_VAL_INT; 159 } 160 161 return -EINVAL; 162 } 163 164 static int mma7455_write_raw(struct iio_dev *indio_dev, 165 struct iio_chan_spec const *chan, 166 int val, int val2, long mask) 167 { 168 struct mma7455_data *mma7455 = iio_priv(indio_dev); 169 int i; 170 171 switch (mask) { 172 case IIO_CHAN_INFO_SAMP_FREQ: 173 if (val == 250 && val2 == 0) 174 i = MMA7455_CTL1_DFBW_125HZ; 175 else if (val == 125 && val2 == 0) 176 i = MMA7455_CTL1_DFBW_62_5HZ; 177 else 178 return -EINVAL; 179 180 return regmap_update_bits(mma7455->regmap, MMA7455_REG_CTL1, 181 MMA7455_CTL1_DFBW_MASK, i); 182 183 case IIO_CHAN_INFO_SCALE: 184 /* In 10-bit mode there is only one scale available */ 185 if (val == 0 && val2 == MMA7455_10BIT_SCALE) 186 return 0; 187 break; 188 } 189 190 return -EINVAL; 191 } 192 193 static IIO_CONST_ATTR(sampling_frequency_available, "125 250"); 194 195 static struct attribute *mma7455_attributes[] = { 196 &iio_const_attr_sampling_frequency_available.dev_attr.attr, 197 NULL 198 }; 199 200 static const struct attribute_group mma7455_group = { 201 .attrs = mma7455_attributes, 202 }; 203 204 static const struct iio_info mma7455_info = { 205 .attrs = &mma7455_group, 206 .read_raw = mma7455_read_raw, 207 .write_raw = mma7455_write_raw, 208 }; 209 210 #define MMA7455_CHANNEL(axis, idx) { \ 211 .type = IIO_ACCEL, \ 212 .modified = 1, \ 213 .address = MMA7455_REG_##axis##OUTL,\ 214 .channel2 = IIO_MOD_##axis, \ 215 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 216 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \ 217 BIT(IIO_CHAN_INFO_SCALE), \ 218 .scan_index = idx, \ 219 .scan_type = { \ 220 .sign = 's', \ 221 .realbits = 10, \ 222 .storagebits = 16, \ 223 .endianness = IIO_LE, \ 224 }, \ 225 } 226 227 static const struct iio_chan_spec mma7455_channels[] = { 228 MMA7455_CHANNEL(X, 0), 229 MMA7455_CHANNEL(Y, 1), 230 MMA7455_CHANNEL(Z, 2), 231 IIO_CHAN_SOFT_TIMESTAMP(3), 232 }; 233 234 static const unsigned long mma7455_scan_masks[] = {0x7, 0}; 235 236 const struct regmap_config mma7455_core_regmap = { 237 .reg_bits = 8, 238 .val_bits = 8, 239 .max_register = MMA7455_REG_TW, 240 }; 241 EXPORT_SYMBOL_GPL(mma7455_core_regmap); 242 243 int mma7455_core_probe(struct device *dev, struct regmap *regmap, 244 const char *name) 245 { 246 struct mma7455_data *mma7455; 247 struct iio_dev *indio_dev; 248 unsigned int reg; 249 int ret; 250 251 ret = regmap_read(regmap, MMA7455_REG_WHOAMI, ®); 252 if (ret) { 253 dev_err(dev, "unable to read reg\n"); 254 return ret; 255 } 256 257 if (reg != MMA7455_WHOAMI_ID) { 258 dev_err(dev, "device id mismatch\n"); 259 return -ENODEV; 260 } 261 262 indio_dev = devm_iio_device_alloc(dev, sizeof(*mma7455)); 263 if (!indio_dev) 264 return -ENOMEM; 265 266 dev_set_drvdata(dev, indio_dev); 267 mma7455 = iio_priv(indio_dev); 268 mma7455->regmap = regmap; 269 270 indio_dev->info = &mma7455_info; 271 indio_dev->name = name; 272 indio_dev->modes = INDIO_DIRECT_MODE; 273 indio_dev->channels = mma7455_channels; 274 indio_dev->num_channels = ARRAY_SIZE(mma7455_channels); 275 indio_dev->available_scan_masks = mma7455_scan_masks; 276 277 regmap_write(mma7455->regmap, MMA7455_REG_MCTL, 278 MMA7455_MCTL_MODE_MEASURE); 279 280 ret = iio_triggered_buffer_setup(indio_dev, NULL, 281 mma7455_trigger_handler, NULL); 282 if (ret) { 283 dev_err(dev, "unable to setup triggered buffer\n"); 284 return ret; 285 } 286 287 ret = iio_device_register(indio_dev); 288 if (ret) { 289 dev_err(dev, "unable to register device\n"); 290 iio_triggered_buffer_cleanup(indio_dev); 291 return ret; 292 } 293 294 return 0; 295 } 296 EXPORT_SYMBOL_GPL(mma7455_core_probe); 297 298 void mma7455_core_remove(struct device *dev) 299 { 300 struct iio_dev *indio_dev = dev_get_drvdata(dev); 301 struct mma7455_data *mma7455 = iio_priv(indio_dev); 302 303 iio_device_unregister(indio_dev); 304 iio_triggered_buffer_cleanup(indio_dev); 305 306 regmap_write(mma7455->regmap, MMA7455_REG_MCTL, 307 MMA7455_MCTL_MODE_STANDBY); 308 } 309 EXPORT_SYMBOL_GPL(mma7455_core_remove); 310 311 MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>"); 312 MODULE_DESCRIPTION("Freescale MMA7455L core accelerometer driver"); 313 MODULE_LICENSE("GPL v2"); 314