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 = tcs3472_req_data(data); 120 if (ret < 0) 121 return ret; 122 ret = i2c_smbus_read_word_data(data->client, chan->address); 123 if (ret < 0) 124 return ret; 125 *val = ret; 126 return IIO_VAL_INT; 127 case IIO_CHAN_INFO_CALIBSCALE: 128 *val = tcs3472_agains[data->control & 129 TCS3472_CONTROL_AGAIN_MASK]; 130 return IIO_VAL_INT; 131 case IIO_CHAN_INFO_INT_TIME: 132 *val = 0; 133 *val2 = (256 - data->atime) * 2400; 134 return IIO_VAL_INT_PLUS_MICRO; 135 } 136 return -EINVAL; 137 } 138 139 static int tcs3472_write_raw(struct iio_dev *indio_dev, 140 struct iio_chan_spec const *chan, 141 int val, int val2, long mask) 142 { 143 struct tcs3472_data *data = iio_priv(indio_dev); 144 int i; 145 146 switch (mask) { 147 case IIO_CHAN_INFO_CALIBSCALE: 148 if (val2 != 0) 149 return -EINVAL; 150 for (i = 0; i < ARRAY_SIZE(tcs3472_agains); i++) { 151 if (val == tcs3472_agains[i]) { 152 data->control &= ~TCS3472_CONTROL_AGAIN_MASK; 153 data->control |= i; 154 return i2c_smbus_write_byte_data( 155 data->client, TCS3472_CONTROL, 156 data->control); 157 } 158 } 159 return -EINVAL; 160 case IIO_CHAN_INFO_INT_TIME: 161 if (val != 0) 162 return -EINVAL; 163 for (i = 0; i < 256; i++) { 164 if (val2 == (256 - i) * 2400) { 165 data->atime = i; 166 return i2c_smbus_write_word_data( 167 data->client, TCS3472_ATIME, 168 data->atime); 169 } 170 171 } 172 return -EINVAL; 173 } 174 return -EINVAL; 175 } 176 177 static irqreturn_t tcs3472_trigger_handler(int irq, void *p) 178 { 179 struct iio_poll_func *pf = p; 180 struct iio_dev *indio_dev = pf->indio_dev; 181 struct tcs3472_data *data = iio_priv(indio_dev); 182 int len = 0; 183 int i, j = 0; 184 185 int ret = tcs3472_req_data(data); 186 if (ret < 0) 187 goto done; 188 189 for_each_set_bit(i, indio_dev->active_scan_mask, 190 indio_dev->masklength) { 191 ret = i2c_smbus_read_word_data(data->client, 192 TCS3472_CDATA + 2*i); 193 if (ret < 0) 194 goto done; 195 196 data->buffer[j++] = ret; 197 len += 2; 198 } 199 200 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, 201 iio_get_time_ns()); 202 203 done: 204 iio_trigger_notify_done(indio_dev->trig); 205 206 return IRQ_HANDLED; 207 } 208 209 static ssize_t tcs3472_show_int_time_available(struct device *dev, 210 struct device_attribute *attr, 211 char *buf) 212 { 213 size_t len = 0; 214 int i; 215 216 for (i = 1; i <= 256; i++) 217 len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06d ", 218 2400 * i); 219 220 /* replace trailing space by newline */ 221 buf[len - 1] = '\n'; 222 223 return len; 224 } 225 226 static IIO_CONST_ATTR(calibscale_available, "1 4 16 60"); 227 static IIO_DEV_ATTR_INT_TIME_AVAIL(tcs3472_show_int_time_available); 228 229 static struct attribute *tcs3472_attributes[] = { 230 &iio_const_attr_calibscale_available.dev_attr.attr, 231 &iio_dev_attr_integration_time_available.dev_attr.attr, 232 NULL 233 }; 234 235 static const struct attribute_group tcs3472_attribute_group = { 236 .attrs = tcs3472_attributes, 237 }; 238 239 static const struct iio_info tcs3472_info = { 240 .read_raw = tcs3472_read_raw, 241 .write_raw = tcs3472_write_raw, 242 .attrs = &tcs3472_attribute_group, 243 .driver_module = THIS_MODULE, 244 }; 245 246 static int tcs3472_probe(struct i2c_client *client, 247 const struct i2c_device_id *id) 248 { 249 struct tcs3472_data *data; 250 struct iio_dev *indio_dev; 251 int ret; 252 253 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 254 if (indio_dev == NULL) 255 return -ENOMEM; 256 257 data = iio_priv(indio_dev); 258 i2c_set_clientdata(client, indio_dev); 259 data->client = client; 260 261 indio_dev->dev.parent = &client->dev; 262 indio_dev->info = &tcs3472_info; 263 indio_dev->name = TCS3472_DRV_NAME; 264 indio_dev->channels = tcs3472_channels; 265 indio_dev->num_channels = ARRAY_SIZE(tcs3472_channels); 266 indio_dev->modes = INDIO_DIRECT_MODE; 267 268 ret = i2c_smbus_read_byte_data(data->client, TCS3472_ID); 269 if (ret < 0) 270 return ret; 271 272 if (ret == 0x44) 273 dev_info(&client->dev, "TCS34721/34725 found\n"); 274 else if (ret == 0x4d) 275 dev_info(&client->dev, "TCS34723/34727 found\n"); 276 else 277 return -ENODEV; 278 279 ret = i2c_smbus_read_byte_data(data->client, TCS3472_CONTROL); 280 if (ret < 0) 281 return ret; 282 data->control = ret; 283 284 ret = i2c_smbus_read_byte_data(data->client, TCS3472_ATIME); 285 if (ret < 0) 286 return ret; 287 data->atime = ret; 288 289 ret = i2c_smbus_read_byte_data(data->client, TCS3472_ENABLE); 290 if (ret < 0) 291 return ret; 292 293 /* enable device */ 294 data->enable = ret | TCS3472_ENABLE_PON | TCS3472_ENABLE_AEN; 295 ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE, 296 data->enable); 297 if (ret < 0) 298 return ret; 299 300 ret = iio_triggered_buffer_setup(indio_dev, NULL, 301 tcs3472_trigger_handler, NULL); 302 if (ret < 0) 303 return ret; 304 305 ret = iio_device_register(indio_dev); 306 if (ret < 0) 307 goto buffer_cleanup; 308 309 return 0; 310 311 buffer_cleanup: 312 iio_triggered_buffer_cleanup(indio_dev); 313 return ret; 314 } 315 316 static int tcs3472_powerdown(struct tcs3472_data *data) 317 { 318 return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE, 319 data->enable & ~(TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON)); 320 } 321 322 static int tcs3472_remove(struct i2c_client *client) 323 { 324 struct iio_dev *indio_dev = i2c_get_clientdata(client); 325 326 iio_device_unregister(indio_dev); 327 iio_triggered_buffer_cleanup(indio_dev); 328 tcs3472_powerdown(iio_priv(indio_dev)); 329 330 return 0; 331 } 332 333 #ifdef CONFIG_PM_SLEEP 334 static int tcs3472_suspend(struct device *dev) 335 { 336 struct tcs3472_data *data = iio_priv(i2c_get_clientdata( 337 to_i2c_client(dev))); 338 return tcs3472_powerdown(data); 339 } 340 341 static int tcs3472_resume(struct device *dev) 342 { 343 struct tcs3472_data *data = iio_priv(i2c_get_clientdata( 344 to_i2c_client(dev))); 345 return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE, 346 data->enable | (TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON)); 347 } 348 #endif 349 350 static SIMPLE_DEV_PM_OPS(tcs3472_pm_ops, tcs3472_suspend, tcs3472_resume); 351 352 static const struct i2c_device_id tcs3472_id[] = { 353 { "tcs3472", 0 }, 354 { } 355 }; 356 MODULE_DEVICE_TABLE(i2c, tcs3472_id); 357 358 static struct i2c_driver tcs3472_driver = { 359 .driver = { 360 .name = TCS3472_DRV_NAME, 361 .pm = &tcs3472_pm_ops, 362 .owner = THIS_MODULE, 363 }, 364 .probe = tcs3472_probe, 365 .remove = tcs3472_remove, 366 .id_table = tcs3472_id, 367 }; 368 module_i2c_driver(tcs3472_driver); 369 370 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>"); 371 MODULE_DESCRIPTION("TCS3472 color light sensors driver"); 372 MODULE_LICENSE("GPL"); 373