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 = IIO_ST('u', 16, 16, 0), \ 71 } 72 73 static const int tcs3472_agains[] = { 1, 4, 16, 60 }; 74 75 static const struct iio_chan_spec tcs3472_channels[] = { 76 TCS3472_CHANNEL(CLEAR, 0, TCS3472_CDATA), 77 TCS3472_CHANNEL(RED, 1, TCS3472_RDATA), 78 TCS3472_CHANNEL(GREEN, 2, TCS3472_GDATA), 79 TCS3472_CHANNEL(BLUE, 3, TCS3472_BDATA), 80 IIO_CHAN_SOFT_TIMESTAMP(4), 81 }; 82 83 static int tcs3472_req_data(struct tcs3472_data *data) 84 { 85 int tries = 50; 86 int ret; 87 88 while (tries--) { 89 ret = i2c_smbus_read_byte_data(data->client, TCS3472_STATUS); 90 if (ret < 0) 91 return ret; 92 if (ret & TCS3472_STATUS_AVALID) 93 break; 94 msleep(20); 95 } 96 97 if (tries < 0) { 98 dev_err(&data->client->dev, "data not ready\n"); 99 return -EIO; 100 } 101 102 return 0; 103 } 104 105 static int tcs3472_read_raw(struct iio_dev *indio_dev, 106 struct iio_chan_spec const *chan, 107 int *val, int *val2, long mask) 108 { 109 struct tcs3472_data *data = iio_priv(indio_dev); 110 int ret; 111 112 switch (mask) { 113 case IIO_CHAN_INFO_RAW: 114 ret = tcs3472_req_data(data); 115 if (ret < 0) 116 return ret; 117 ret = i2c_smbus_read_word_data(data->client, chan->address); 118 if (ret < 0) 119 return ret; 120 *val = ret; 121 return IIO_VAL_INT; 122 case IIO_CHAN_INFO_CALIBSCALE: 123 *val = tcs3472_agains[data->control & 124 TCS3472_CONTROL_AGAIN_MASK]; 125 return IIO_VAL_INT; 126 case IIO_CHAN_INFO_INT_TIME: 127 *val = 0; 128 *val2 = (256 - data->atime) * 2400; 129 return IIO_VAL_INT_PLUS_MICRO; 130 } 131 return -EINVAL; 132 } 133 134 static int tcs3472_write_raw(struct iio_dev *indio_dev, 135 struct iio_chan_spec const *chan, 136 int val, int val2, long mask) 137 { 138 struct tcs3472_data *data = iio_priv(indio_dev); 139 int i; 140 141 switch (mask) { 142 case IIO_CHAN_INFO_CALIBSCALE: 143 if (val2 != 0) 144 return -EINVAL; 145 for (i = 0; i < ARRAY_SIZE(tcs3472_agains); i++) { 146 if (val == tcs3472_agains[i]) { 147 data->control &= ~TCS3472_CONTROL_AGAIN_MASK; 148 data->control |= i; 149 return i2c_smbus_write_byte_data( 150 data->client, TCS3472_CONTROL, 151 data->control); 152 } 153 } 154 return -EINVAL; 155 case IIO_CHAN_INFO_INT_TIME: 156 if (val != 0) 157 return -EINVAL; 158 for (i = 0; i < 256; i++) { 159 if (val2 == (256 - i) * 2400) { 160 data->atime = i; 161 return i2c_smbus_write_word_data( 162 data->client, TCS3472_ATIME, 163 data->atime); 164 } 165 166 } 167 return -EINVAL; 168 } 169 return -EINVAL; 170 } 171 172 static irqreturn_t tcs3472_trigger_handler(int irq, void *p) 173 { 174 struct iio_poll_func *pf = p; 175 struct iio_dev *indio_dev = pf->indio_dev; 176 struct tcs3472_data *data = iio_priv(indio_dev); 177 int len = 0; 178 int i, j = 0; 179 180 int ret = tcs3472_req_data(data); 181 if (ret < 0) 182 goto done; 183 184 for_each_set_bit(i, indio_dev->active_scan_mask, 185 indio_dev->masklength) { 186 ret = i2c_smbus_read_word_data(data->client, 187 TCS3472_CDATA + 2*i); 188 if (ret < 0) 189 goto done; 190 191 data->buffer[j++] = ret; 192 len += 2; 193 } 194 195 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, 196 iio_get_time_ns()); 197 198 done: 199 iio_trigger_notify_done(indio_dev->trig); 200 201 return IRQ_HANDLED; 202 } 203 204 static ssize_t tcs3472_show_int_time_available(struct device *dev, 205 struct device_attribute *attr, 206 char *buf) 207 { 208 size_t len = 0; 209 int i; 210 211 for (i = 1; i <= 256; i++) 212 len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06d ", 213 2400 * i); 214 215 /* replace trailing space by newline */ 216 buf[len - 1] = '\n'; 217 218 return len; 219 } 220 221 static IIO_CONST_ATTR(calibscale_available, "1 4 16 60"); 222 static IIO_DEV_ATTR_INT_TIME_AVAIL(tcs3472_show_int_time_available); 223 224 static struct attribute *tcs3472_attributes[] = { 225 &iio_const_attr_calibscale_available.dev_attr.attr, 226 &iio_dev_attr_integration_time_available.dev_attr.attr, 227 NULL 228 }; 229 230 static const struct attribute_group tcs3472_attribute_group = { 231 .attrs = tcs3472_attributes, 232 }; 233 234 static const struct iio_info tcs3472_info = { 235 .read_raw = tcs3472_read_raw, 236 .write_raw = tcs3472_write_raw, 237 .attrs = &tcs3472_attribute_group, 238 .driver_module = THIS_MODULE, 239 }; 240 241 static int tcs3472_probe(struct i2c_client *client, 242 const struct i2c_device_id *id) 243 { 244 struct tcs3472_data *data; 245 struct iio_dev *indio_dev; 246 int ret; 247 248 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 249 if (indio_dev == NULL) 250 return -ENOMEM; 251 252 data = iio_priv(indio_dev); 253 i2c_set_clientdata(client, indio_dev); 254 data->client = client; 255 256 indio_dev->dev.parent = &client->dev; 257 indio_dev->info = &tcs3472_info; 258 indio_dev->name = TCS3472_DRV_NAME; 259 indio_dev->channels = tcs3472_channels; 260 indio_dev->num_channels = ARRAY_SIZE(tcs3472_channels); 261 indio_dev->modes = INDIO_DIRECT_MODE; 262 263 ret = i2c_smbus_read_byte_data(data->client, TCS3472_ID); 264 if (ret < 0) 265 return ret; 266 267 if (ret == 0x44) 268 dev_info(&client->dev, "TCS34721/34725 found\n"); 269 else if (ret == 0x4d) 270 dev_info(&client->dev, "TCS34723/34727 found\n"); 271 else 272 return -ENODEV; 273 274 ret = i2c_smbus_read_byte_data(data->client, TCS3472_CONTROL); 275 if (ret < 0) 276 return ret; 277 data->control = ret; 278 279 ret = i2c_smbus_read_byte_data(data->client, TCS3472_ATIME); 280 if (ret < 0) 281 return ret; 282 data->atime = ret; 283 284 ret = i2c_smbus_read_byte_data(data->client, TCS3472_ENABLE); 285 if (ret < 0) 286 return ret; 287 288 /* enable device */ 289 data->enable = ret | TCS3472_ENABLE_PON | TCS3472_ENABLE_AEN; 290 ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE, 291 data->enable); 292 if (ret < 0) 293 return ret; 294 295 ret = iio_triggered_buffer_setup(indio_dev, NULL, 296 tcs3472_trigger_handler, NULL); 297 if (ret < 0) 298 return ret; 299 300 ret = iio_device_register(indio_dev); 301 if (ret < 0) 302 goto buffer_cleanup; 303 304 return 0; 305 306 buffer_cleanup: 307 iio_triggered_buffer_cleanup(indio_dev); 308 return ret; 309 } 310 311 static int tcs3472_powerdown(struct tcs3472_data *data) 312 { 313 return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE, 314 data->enable & ~(TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON)); 315 } 316 317 static int tcs3472_remove(struct i2c_client *client) 318 { 319 struct iio_dev *indio_dev = i2c_get_clientdata(client); 320 321 iio_device_unregister(indio_dev); 322 iio_triggered_buffer_cleanup(indio_dev); 323 tcs3472_powerdown(iio_priv(indio_dev)); 324 325 return 0; 326 } 327 328 #ifdef CONFIG_PM_SLEEP 329 static int tcs3472_suspend(struct device *dev) 330 { 331 struct tcs3472_data *data = iio_priv(i2c_get_clientdata( 332 to_i2c_client(dev))); 333 return tcs3472_powerdown(data); 334 } 335 336 static int tcs3472_resume(struct device *dev) 337 { 338 struct tcs3472_data *data = iio_priv(i2c_get_clientdata( 339 to_i2c_client(dev))); 340 return i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE, 341 data->enable | (TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON)); 342 } 343 #endif 344 345 static SIMPLE_DEV_PM_OPS(tcs3472_pm_ops, tcs3472_suspend, tcs3472_resume); 346 347 static const struct i2c_device_id tcs3472_id[] = { 348 { "tcs3472", 0 }, 349 { } 350 }; 351 MODULE_DEVICE_TABLE(i2c, tcs3472_id); 352 353 static struct i2c_driver tcs3472_driver = { 354 .driver = { 355 .name = TCS3472_DRV_NAME, 356 .pm = &tcs3472_pm_ops, 357 .owner = THIS_MODULE, 358 }, 359 .probe = tcs3472_probe, 360 .remove = tcs3472_remove, 361 .id_table = tcs3472_id, 362 }; 363 module_i2c_driver(tcs3472_driver); 364 365 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>"); 366 MODULE_DESCRIPTION("TCS3472 color light sensors driver"); 367 MODULE_LICENSE("GPL"); 368