1 /* 2 * tcs3472.c - Support for TAOS TCS3472 color light-to-digital converter 3 * 4 * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net> 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 * Color light sensor with 16-bit channels for red, green, blue, clear); 11 * 7-bit I2C slave address 0x39 (TCS34721, TCS34723) or 0x29 (TCS34725, 12 * TCS34727) 13 * 14 * TODO: interrupt support, thresholds, wait time 15 */ 16 17 #include <linux/module.h> 18 #include <linux/i2c.h> 19 #include <linux/delay.h> 20 #include <linux/pm.h> 21 22 #include <linux/iio/iio.h> 23 #include <linux/iio/sysfs.h> 24 #include <linux/iio/trigger_consumer.h> 25 #include <linux/iio/buffer.h> 26 #include <linux/iio/triggered_buffer.h> 27 28 #define TCS3472_DRV_NAME "tcs3472" 29 30 #define TCS3472_COMMAND BIT(7) 31 #define TCS3472_AUTO_INCR BIT(5) 32 33 #define TCS3472_ENABLE (TCS3472_COMMAND | 0x00) 34 #define TCS3472_ATIME (TCS3472_COMMAND | 0x01) 35 #define TCS3472_WTIME (TCS3472_COMMAND | 0x03) 36 #define TCS3472_AILT (TCS3472_COMMAND | 0x04) 37 #define TCS3472_AIHT (TCS3472_COMMAND | 0x06) 38 #define TCS3472_PERS (TCS3472_COMMAND | 0x0c) 39 #define TCS3472_CONFIG (TCS3472_COMMAND | 0x0d) 40 #define TCS3472_CONTROL (TCS3472_COMMAND | 0x0f) 41 #define TCS3472_ID (TCS3472_COMMAND | 0x12) 42 #define TCS3472_STATUS (TCS3472_COMMAND | 0x13) 43 #define TCS3472_CDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x14) 44 #define TCS3472_RDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x16) 45 #define TCS3472_GDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x18) 46 #define TCS3472_BDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x1a) 47 48 #define TCS3472_STATUS_AVALID BIT(0) 49 #define TCS3472_ENABLE_AEN BIT(1) 50 #define TCS3472_ENABLE_PON BIT(0) 51 #define TCS3472_CONTROL_AGAIN_MASK (BIT(0) | BIT(1)) 52 53 struct tcs3472_data { 54 struct i2c_client *client; 55 u8 enable; 56 u8 control; 57 u8 atime; 58 u16 buffer[8]; /* 4 16-bit channels + 64-bit timestamp */ 59 }; 60 61 #define TCS3472_CHANNEL(_color, _si, _addr) { \ 62 .type = IIO_INTENSITY, \ 63 .modified = 1, \ 64 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 65 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBSCALE) | \ 66 BIT(IIO_CHAN_INFO_INT_TIME), \ 67 .channel2 = IIO_MOD_LIGHT_##_color, \ 68 .address = _addr, \ 69 .scan_index = _si, \ 70 .scan_type = { \ 71 .sign = 'u', \ 72 .realbits = 16, \ 73 .storagebits = 16, \ 74 .endianness = IIO_CPU, \ 75 }, \ 76 } 77 78 static const int tcs3472_agains[] = { 1, 4, 16, 60 }; 79 80 static const struct iio_chan_spec tcs3472_channels[] = { 81 TCS3472_CHANNEL(CLEAR, 0, TCS3472_CDATA), 82 TCS3472_CHANNEL(RED, 1, TCS3472_RDATA), 83 TCS3472_CHANNEL(GREEN, 2, TCS3472_GDATA), 84 TCS3472_CHANNEL(BLUE, 3, TCS3472_BDATA), 85 IIO_CHAN_SOFT_TIMESTAMP(4), 86 }; 87 88 static int tcs3472_req_data(struct tcs3472_data *data) 89 { 90 int tries = 50; 91 int ret; 92 93 while (tries--) { 94 ret = i2c_smbus_read_byte_data(data->client, TCS3472_STATUS); 95 if (ret < 0) 96 return ret; 97 if (ret & TCS3472_STATUS_AVALID) 98 break; 99 msleep(20); 100 } 101 102 if (tries < 0) { 103 dev_err(&data->client->dev, "data not ready\n"); 104 return -EIO; 105 } 106 107 return 0; 108 } 109 110 static int tcs3472_read_raw(struct iio_dev *indio_dev, 111 struct iio_chan_spec const *chan, 112 int *val, int *val2, long mask) 113 { 114 struct tcs3472_data *data = iio_priv(indio_dev); 115 int ret; 116 117 switch (mask) { 118 case IIO_CHAN_INFO_RAW: 119 ret = iio_device_claim_direct_mode(indio_dev); 120 if (ret) 121 return ret; 122 ret = tcs3472_req_data(data); 123 if (ret < 0) { 124 iio_device_release_direct_mode(indio_dev); 125 return ret; 126 } 127 ret = i2c_smbus_read_word_data(data->client, chan->address); 128 iio_device_release_direct_mode(indio_dev); 129 if (ret < 0) 130 return ret; 131 *val = ret; 132 return IIO_VAL_INT; 133 case IIO_CHAN_INFO_CALIBSCALE: 134 *val = tcs3472_agains[data->control & 135 TCS3472_CONTROL_AGAIN_MASK]; 136 return IIO_VAL_INT; 137 case IIO_CHAN_INFO_INT_TIME: 138 *val = 0; 139 *val2 = (256 - data->atime) * 2400; 140 return IIO_VAL_INT_PLUS_MICRO; 141 } 142 return -EINVAL; 143 } 144 145 static int tcs3472_write_raw(struct iio_dev *indio_dev, 146 struct iio_chan_spec const *chan, 147 int val, int val2, long mask) 148 { 149 struct tcs3472_data *data = iio_priv(indio_dev); 150 int i; 151 152 switch (mask) { 153 case IIO_CHAN_INFO_CALIBSCALE: 154 if (val2 != 0) 155 return -EINVAL; 156 for (i = 0; i < ARRAY_SIZE(tcs3472_agains); i++) { 157 if (val == tcs3472_agains[i]) { 158 data->control &= ~TCS3472_CONTROL_AGAIN_MASK; 159 data->control |= i; 160 return i2c_smbus_write_byte_data( 161 data->client, TCS3472_CONTROL, 162 data->control); 163 } 164 } 165 return -EINVAL; 166 case IIO_CHAN_INFO_INT_TIME: 167 if (val != 0) 168 return -EINVAL; 169 for (i = 0; i < 256; i++) { 170 if (val2 == (256 - i) * 2400) { 171 data->atime = i; 172 return i2c_smbus_write_word_data( 173 data->client, TCS3472_ATIME, 174 data->atime); 175 } 176 177 } 178 return -EINVAL; 179 } 180 return -EINVAL; 181 } 182 183 static irqreturn_t tcs3472_trigger_handler(int irq, void *p) 184 { 185 struct iio_poll_func *pf = p; 186 struct iio_dev *indio_dev = pf->indio_dev; 187 struct tcs3472_data *data = iio_priv(indio_dev); 188 int i, j = 0; 189 190 int ret = tcs3472_req_data(data); 191 if (ret < 0) 192 goto done; 193 194 for_each_set_bit(i, indio_dev->active_scan_mask, 195 indio_dev->masklength) { 196 ret = i2c_smbus_read_word_data(data->client, 197 TCS3472_CDATA + 2*i); 198 if (ret < 0) 199 goto done; 200 201 data->buffer[j++] = ret; 202 } 203 204 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, 205 iio_get_time_ns(indio_dev)); 206 207 done: 208 iio_trigger_notify_done(indio_dev->trig); 209 210 return IRQ_HANDLED; 211 } 212 213 static ssize_t tcs3472_show_int_time_available(struct device *dev, 214 struct device_attribute *attr, 215 char *buf) 216 { 217 size_t len = 0; 218 int i; 219 220 for (i = 1; i <= 256; i++) 221 len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06d ", 222 2400 * i); 223 224 /* replace trailing space by newline */ 225 buf[len - 1] = '\n'; 226 227 return len; 228 } 229 230 static IIO_CONST_ATTR(calibscale_available, "1 4 16 60"); 231 static IIO_DEV_ATTR_INT_TIME_AVAIL(tcs3472_show_int_time_available); 232 233 static struct attribute *tcs3472_attributes[] = { 234 &iio_const_attr_calibscale_available.dev_attr.attr, 235 &iio_dev_attr_integration_time_available.dev_attr.attr, 236 NULL 237 }; 238 239 static const struct attribute_group tcs3472_attribute_group = { 240 .attrs = tcs3472_attributes, 241 }; 242 243 static const struct iio_info tcs3472_info = { 244 .read_raw = tcs3472_read_raw, 245 .write_raw = tcs3472_write_raw, 246 .attrs = &tcs3472_attribute_group, 247 .driver_module = THIS_MODULE, 248 }; 249 250 static int tcs3472_probe(struct i2c_client *client, 251 const struct i2c_device_id *id) 252 { 253 struct tcs3472_data *data; 254 struct iio_dev *indio_dev; 255 int ret; 256 257 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 258 if (indio_dev == NULL) 259 return -ENOMEM; 260 261 data = iio_priv(indio_dev); 262 i2c_set_clientdata(client, indio_dev); 263 data->client = client; 264 265 indio_dev->dev.parent = &client->dev; 266 indio_dev->info = &tcs3472_info; 267 indio_dev->name = TCS3472_DRV_NAME; 268 indio_dev->channels = tcs3472_channels; 269 indio_dev->num_channels = ARRAY_SIZE(tcs3472_channels); 270 indio_dev->modes = INDIO_DIRECT_MODE; 271 272 ret = i2c_smbus_read_byte_data(data->client, TCS3472_ID); 273 if (ret < 0) 274 return ret; 275 276 if (ret == 0x44) 277 dev_info(&client->dev, "TCS34721/34725 found\n"); 278 else if (ret == 0x4d) 279 dev_info(&client->dev, "TCS34723/34727 found\n"); 280 else 281 return -ENODEV; 282 283 ret = i2c_smbus_read_byte_data(data->client, TCS3472_CONTROL); 284 if (ret < 0) 285 return ret; 286 data->control = ret; 287 288 ret = i2c_smbus_read_byte_data(data->client, TCS3472_ATIME); 289 if (ret < 0) 290 return ret; 291 data->atime = ret; 292 293 ret = i2c_smbus_read_byte_data(data->client, TCS3472_ENABLE); 294 if (ret < 0) 295 return ret; 296 297 /* enable device */ 298 data->enable = ret | TCS3472_ENABLE_PON | TCS3472_ENABLE_AEN; 299 ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE, 300 data->enable); 301 if (ret < 0) 302 return ret; 303 304 ret = iio_triggered_buffer_setup(indio_dev, NULL, 305 tcs3472_trigger_handler, NULL); 306 if (ret < 0) 307 return ret; 308 309 ret = iio_device_register(indio_dev); 310 if (ret < 0) 311 goto buffer_cleanup; 312 313 return 0; 314 315 buffer_cleanup: 316 iio_triggered_buffer_cleanup(indio_dev); 317 return ret; 318 } 319 320 static int tcs3472_powerdown(struct tcs3472_data *data) 321 { 322 return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE, 323 data->enable & ~(TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON)); 324 } 325 326 static int tcs3472_remove(struct i2c_client *client) 327 { 328 struct iio_dev *indio_dev = i2c_get_clientdata(client); 329 330 iio_device_unregister(indio_dev); 331 iio_triggered_buffer_cleanup(indio_dev); 332 tcs3472_powerdown(iio_priv(indio_dev)); 333 334 return 0; 335 } 336 337 #ifdef CONFIG_PM_SLEEP 338 static int tcs3472_suspend(struct device *dev) 339 { 340 struct tcs3472_data *data = iio_priv(i2c_get_clientdata( 341 to_i2c_client(dev))); 342 return tcs3472_powerdown(data); 343 } 344 345 static int tcs3472_resume(struct device *dev) 346 { 347 struct tcs3472_data *data = iio_priv(i2c_get_clientdata( 348 to_i2c_client(dev))); 349 return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE, 350 data->enable | (TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON)); 351 } 352 #endif 353 354 static SIMPLE_DEV_PM_OPS(tcs3472_pm_ops, tcs3472_suspend, tcs3472_resume); 355 356 static const struct i2c_device_id tcs3472_id[] = { 357 { "tcs3472", 0 }, 358 { } 359 }; 360 MODULE_DEVICE_TABLE(i2c, tcs3472_id); 361 362 static struct i2c_driver tcs3472_driver = { 363 .driver = { 364 .name = TCS3472_DRV_NAME, 365 .pm = &tcs3472_pm_ops, 366 }, 367 .probe = tcs3472_probe, 368 .remove = tcs3472_remove, 369 .id_table = tcs3472_id, 370 }; 371 module_i2c_driver(tcs3472_driver); 372 373 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>"); 374 MODULE_DESCRIPTION("TCS3472 color light sensors driver"); 375 MODULE_LICENSE("GPL"); 376