2 * drivers/i2c/chips/tsl2563.c
4 * Copyright (C) 2008 Nokia Corporation
6 * Written by Timo O. Karjalainen <timo.o.karjalainen@nokia.com>
7 * Contact: Mathias Nyman <mathias.nyman@nokia.com>
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * version 2 as published by the Free Software Foundation.
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
24 #include <linux/module.h>
25 #include <linux/i2c.h>
26 #include <linux/interrupt.h>
27 #include <linux/sched.h>
28 #include <linux/mutex.h>
29 #include <linux/delay.h>
30 #include <linux/platform_device.h>
32 #include <linux/hwmon.h>
33 #include <linux/err.h>
34 #include <mach/board.h>
36 #define DRIVER_NAME "tsl2563"
38 /* Use this many bits for fraction part. */
39 #define ADC_FRAC_BITS (14)
41 /* Given number of 1/10000's in ADC_FRAC_BITS precision. */
42 #define FRAC10K(f) (((f) * (1L << (ADC_FRAC_BITS))) / (10000))
44 /* Bits used for fraction in calibration coefficients.*/
45 #define CALIB_FRAC_BITS (10)
46 /* 0.5 in CALIB_FRAC_BITS precision */
47 #define CALIB_FRAC_HALF (1 << (CALIB_FRAC_BITS - 1))
48 /* Make a fraction from a number n that was multiplied with b. */
49 #define CALIB_FRAC(n, b) (((n) << CALIB_FRAC_BITS) / (b))
50 /* Decimal 10^(digits in sysfs presentation) */
51 #define CALIB_BASE_SYSFS (1000)
53 #define TSL2563_CMD (0x80)
54 #define TSL2563_CLEARINT (0x40)
56 #define TSL2563_REG_CTRL (0x00)
57 #define TSL2563_REG_TIMING (0x01)
58 #define TSL2563_REG_LOWLOW (0x02) /* data0 low threshold, 2 bytes */
59 #define TSL2563_REG_LOWHIGH (0x03)
60 #define TSL2563_REG_HIGHLOW (0x04) /* data0 high threshold, 2 bytes */
61 #define TSL2563_REG_HIGHHIGH (0x05)
62 #define TSL2563_REG_INT (0x06)
63 #define TSL2563_REG_ID (0x0a)
64 #define TSL2563_REG_DATA0LOW (0x0c) /* broadband sensor value, 2 bytes */
65 #define TSL2563_REG_DATA0HIGH (0x0d)
66 #define TSL2563_REG_DATA1LOW (0x0e) /* infrared sensor value, 2 bytes */
67 #define TSL2563_REG_DATA1HIGH (0x0f)
69 #define TSL2563_CMD_POWER_ON (0x03)
70 #define TSL2563_CMD_POWER_OFF (0x00)
71 #define TSL2563_CTRL_POWER_MASK (0x03)
73 #define TSL2563_TIMING_13MS (0x00)
74 #define TSL2563_TIMING_100MS (0x01)
75 #define TSL2563_TIMING_400MS (0x02)
76 #define TSL2563_TIMING_MASK (0x03)
77 #define TSL2563_TIMING_GAIN16 (0x10)
78 #define TSL2563_TIMING_GAIN1 (0x00)
80 #define TSL2563_INT_DISBLED (0x00)
81 #define TSL2563_INT_LEVEL (0x10)
82 #define TSL2563_INT_PERSIST(n) ((n) & 0x0F)
84 struct tsl2563_gainlevel_coeff {
90 static struct tsl2563_gainlevel_coeff tsl2563_gainlevel_table[] = {
92 .gaintime = TSL2563_TIMING_400MS | TSL2563_TIMING_GAIN16,
96 .gaintime = TSL2563_TIMING_400MS | TSL2563_TIMING_GAIN1,
100 .gaintime = TSL2563_TIMING_100MS | TSL2563_TIMING_GAIN1,
104 .gaintime = TSL2563_TIMING_13MS | TSL2563_TIMING_GAIN1,
110 struct tsl2563_chip {
112 struct i2c_client *client;
113 struct device *hwmon_dev;
115 /* Remember state for suspend and resume functions */
118 struct tsl2563_gainlevel_coeff *gainlevel;
120 /* Thresholds are in lux */
125 /* Calibration coefficients */
129 /* Cache current values, to be returned while suspended */
134 static int tsl2563_write(struct i2c_client *client, u8 reg, u8 value)
139 buf[0] = TSL2563_CMD | reg;
142 ret = i2c_master_send(client, buf, sizeof(buf));
143 return (ret == sizeof(buf)) ? 0 : ret;
146 static int tsl2563_read(struct i2c_client *client, u8 reg, void *buf, int len)
149 u8 cmd = TSL2563_CMD | reg;
151 ret = i2c_master_send(client, &cmd, sizeof(cmd));
152 if (ret != sizeof(cmd))
155 return i2c_master_recv(client, buf, len);
158 static int tsl2563_set_power(struct tsl2563_chip *chip, int on)
160 struct i2c_client *client = chip->client;
163 cmd = on ? TSL2563_CMD_POWER_ON : TSL2563_CMD_POWER_OFF;
164 return tsl2563_write(client, TSL2563_REG_CTRL, cmd);
168 * Return value is 0 for off, 1 for on, or a negative error
169 * code if reading failed.
171 static int tsl2563_get_power(struct tsl2563_chip *chip)
173 struct i2c_client *client = chip->client;
177 ret = tsl2563_read(client, TSL2563_REG_CTRL, &val, sizeof(val));
178 if (ret != sizeof(val))
181 return (val & TSL2563_CTRL_POWER_MASK) == TSL2563_CMD_POWER_ON;
184 static int tsl2563_configure(struct tsl2563_chip *chip)
186 struct i2c_client *client = chip->client;
189 ret = tsl2563_write(client, TSL2563_REG_TIMING,
190 chip->gainlevel->gaintime);
194 ret = tsl2563_write(client, TSL2563_REG_INT, chip->intr);
200 static int tsl2563_detect(struct tsl2563_chip *chip)
204 ret = tsl2563_set_power(chip, 1);
208 ret = tsl2563_get_power(chip);
212 return ret ? 0 : -ENODEV;
215 static int tsl2563_read_id(struct tsl2563_chip *chip, u8 *id)
217 struct i2c_client *client = chip->client;
220 ret = tsl2563_read(client, TSL2563_REG_ID, id, sizeof(*id));
221 if (ret != sizeof(*id))
228 * "Normalized" ADC value is one obtained with 400ms of integration time and
229 * 16x gain. This function returns the number of bits of shift needed to
230 * convert between normalized values and HW values obtained using given
231 * timing and gain settings.
233 static int adc_shiftbits(u8 timing)
237 switch (timing & TSL2563_TIMING_MASK) {
238 case TSL2563_TIMING_13MS:
241 case TSL2563_TIMING_100MS:
244 case TSL2563_TIMING_400MS:
249 if (!(timing & TSL2563_TIMING_GAIN16))
255 /* Convert a HW ADC value to normalized scale. */
256 static u32 normalize_adc(u16 adc, u8 timing)
258 return adc << adc_shiftbits(timing);
261 static void tsl2563_wait_adc(struct tsl2563_chip *chip)
265 switch (chip->gainlevel->gaintime & TSL2563_TIMING_MASK) {
266 case TSL2563_TIMING_13MS:
269 case TSL2563_TIMING_100MS:
276 * TODO: Make sure that we wait at least required delay but why we
277 * have to extend it one tick more?
279 schedule_timeout_interruptible(msecs_to_jiffies(delay) + 2);
282 static int tsl2563_adjust_gainlevel(struct tsl2563_chip *chip, u16 adc)
284 struct i2c_client *client = chip->client;
286 if (adc > chip->gainlevel->max || adc < chip->gainlevel->min) {
288 (adc > chip->gainlevel->max) ?
289 chip->gainlevel++ : chip->gainlevel--;
291 tsl2563_write(client, TSL2563_REG_TIMING,
292 chip->gainlevel->gaintime);
294 tsl2563_wait_adc(chip);
295 tsl2563_wait_adc(chip);
302 static int tsl2563_get_adc(struct tsl2563_chip *chip)
304 struct i2c_client *client = chip->client;
310 if (chip->state.event != PM_EVENT_ON)
314 ret = tsl2563_read(client,
315 TSL2563_REG_DATA0LOW | TSL2563_CLEARINT,
317 if (ret != sizeof(buf0))
320 ret = tsl2563_read(client, TSL2563_REG_DATA1LOW,
322 if (ret != sizeof(buf1))
325 adc0 = (buf0[1] << 8) + buf0[0];
326 adc1 = (buf1[1] << 8) + buf1[0];
328 retry = tsl2563_adjust_gainlevel(chip, adc0);
331 chip->data0 = normalize_adc(adc0, chip->gainlevel->gaintime);
332 chip->data1 = normalize_adc(adc1, chip->gainlevel->gaintime);
339 static inline int calib_to_sysfs(u32 calib)
341 return (int) (((calib * CALIB_BASE_SYSFS) +
342 CALIB_FRAC_HALF) >> CALIB_FRAC_BITS);
345 static inline u32 calib_from_sysfs(int value)
347 return (((u32) value) << CALIB_FRAC_BITS) / CALIB_BASE_SYSFS;
351 * Conversions between lux and ADC values.
353 * The basic formula is lux = c0 * adc0 - c1 * adc1, where c0 and c1 are
354 * appropriate constants. Different constants are needed for different
355 * kinds of light, determined by the ratio adc1/adc0 (basically the ratio
356 * of the intensities in infrared and visible wavelengths). lux_table below
357 * lists the upper threshold of the adc1/adc0 ratio and the corresponding
361 struct tsl2563_lux_coeff {
362 unsigned long ch_ratio;
363 unsigned long ch0_coeff;
364 unsigned long ch1_coeff;
367 static const struct tsl2563_lux_coeff lux_table[] = {
369 .ch_ratio = FRAC10K(1300),
370 .ch0_coeff = FRAC10K(315),
371 .ch1_coeff = FRAC10K(262),
373 .ch_ratio = FRAC10K(2600),
374 .ch0_coeff = FRAC10K(337),
375 .ch1_coeff = FRAC10K(430),
377 .ch_ratio = FRAC10K(3900),
378 .ch0_coeff = FRAC10K(363),
379 .ch1_coeff = FRAC10K(529),
381 .ch_ratio = FRAC10K(5200),
382 .ch0_coeff = FRAC10K(392),
383 .ch1_coeff = FRAC10K(605),
385 .ch_ratio = FRAC10K(6500),
386 .ch0_coeff = FRAC10K(229),
387 .ch1_coeff = FRAC10K(291),
389 .ch_ratio = FRAC10K(8000),
390 .ch0_coeff = FRAC10K(157),
391 .ch1_coeff = FRAC10K(180),
393 .ch_ratio = FRAC10K(13000),
394 .ch0_coeff = FRAC10K(34),
395 .ch1_coeff = FRAC10K(26),
397 .ch_ratio = ULONG_MAX,
404 * Convert normalized, scaled ADC values to lux.
406 static unsigned int adc_to_lux(u32 adc0, u32 adc1)
408 const struct tsl2563_lux_coeff *lp = lux_table;
409 unsigned long ratio, lux, ch0 = adc0, ch1 = adc1;
411 ratio = ch0 ? ((ch1 << ADC_FRAC_BITS) / ch0) : ULONG_MAX;
413 while (lp->ch_ratio < ratio)
416 lux = ch0 * lp->ch0_coeff - ch1 * lp->ch1_coeff;
418 return (unsigned int) (lux >> ADC_FRAC_BITS);
421 /*--------------------------------------------------------------*/
422 /* Sysfs interface */
423 /*--------------------------------------------------------------*/
425 static ssize_t tsl2563_adc0_show(struct device *dev,
426 struct device_attribute *attr, char *buf)
428 struct tsl2563_chip *chip = dev_get_drvdata(dev);
431 mutex_lock(&chip->lock);
433 ret = tsl2563_get_adc(chip);
437 ret = snprintf(buf, PAGE_SIZE, "%d\n", chip->data0);
438 mutex_unlock(&chip->lock);
443 static ssize_t tsl2563_adc1_show(struct device *dev,
444 struct device_attribute *attr, char *buf)
446 struct tsl2563_chip *chip = dev_get_drvdata(dev);
449 mutex_lock(&chip->lock);
451 ret = tsl2563_get_adc(chip);
455 ret = snprintf(buf, PAGE_SIZE, "%d\n", chip->data1);
456 mutex_unlock(&chip->lock);
461 /* Apply calibration coefficient to ADC count. */
462 static u32 calib_adc(u32 adc, u32 calib)
464 unsigned long scaled = adc;
467 scaled >>= CALIB_FRAC_BITS;
472 static ssize_t tsl2563_lux_show(struct device *dev,
473 struct device_attribute *attr, char *buf)
475 struct tsl2563_chip *chip = dev_get_drvdata(dev);
479 mutex_lock(&chip->lock);
481 ret = tsl2563_get_adc(chip);
485 calib0 = calib_adc(chip->data0, chip->calib0);
486 calib1 = calib_adc(chip->data1, chip->calib1);
488 ret = snprintf(buf, PAGE_SIZE, "%d\n", adc_to_lux(calib0, calib1));
491 mutex_unlock(&chip->lock);
495 static ssize_t format_calib(char *buf, int len, u32 calib)
497 return snprintf(buf, PAGE_SIZE, "%d\n", calib_to_sysfs(calib));
500 static ssize_t tsl2563_calib0_show(struct device *dev,
501 struct device_attribute *attr, char *buf)
503 struct tsl2563_chip *chip = dev_get_drvdata(dev);
506 mutex_lock(&chip->lock);
507 ret = format_calib(buf, PAGE_SIZE, chip->calib0);
508 mutex_unlock(&chip->lock);
512 static ssize_t tsl2563_calib1_show(struct device *dev,
513 struct device_attribute *attr, char *buf)
515 struct tsl2563_chip *chip = dev_get_drvdata(dev);
518 mutex_lock(&chip->lock);
519 ret = format_calib(buf, PAGE_SIZE, chip->calib1);
520 mutex_unlock(&chip->lock);
524 static int do_calib_store(struct device *dev, const char *buf, size_t len,
527 struct tsl2563_chip *chip = dev_get_drvdata(dev);
531 if (1 != sscanf(buf, "%d", &value))
534 calib = calib_from_sysfs(value);
537 chip->calib1 = calib;
539 chip->calib0 = calib;
544 static ssize_t tsl2563_calib0_store(struct device *dev,
545 struct device_attribute *attr,
546 const char *buf, size_t len)
548 return do_calib_store(dev, buf, len, 0);
551 static ssize_t tsl2563_calib1_store(struct device *dev,
552 struct device_attribute *attr,
553 const char *buf, size_t len)
555 return do_calib_store(dev, buf, len, 1);
558 static DEVICE_ATTR(adc0, S_IRUGO, tsl2563_adc0_show, NULL);
559 static DEVICE_ATTR(adc1, S_IRUGO, tsl2563_adc1_show, NULL);
560 static DEVICE_ATTR(lux, S_IRUGO, tsl2563_lux_show, NULL);
561 static DEVICE_ATTR(calib0, S_IRUGO | S_IWUSR,
562 tsl2563_calib0_show, tsl2563_calib0_store);
563 static DEVICE_ATTR(calib1, S_IRUGO | S_IWUSR,
564 tsl2563_calib1_show, tsl2563_calib1_store);
566 static struct attribute *tsl2563_attributes[] = {
570 &dev_attr_calib0.attr,
571 &dev_attr_calib1.attr,
575 static const struct attribute_group tsl2563_group = {
576 .attrs = tsl2563_attributes,
579 static int tsl2563_register_sysfs(struct i2c_client *client)
581 struct device *dev = &client->dev;
583 return sysfs_create_group(&dev->kobj, &tsl2563_group);
586 static void tsl2563_unregister_sysfs(struct i2c_client *client)
588 struct device *dev = &client->dev;
590 sysfs_remove_group(&dev->kobj, &tsl2563_group);
593 /*--------------------------------------------------------------*/
594 /* Probe, Attach, Remove */
595 /*--------------------------------------------------------------*/
596 static struct i2c_driver tsl2563_i2c_driver;
598 static int tsl2563_probe(struct i2c_client *client,
599 const struct i2c_device_id *device_id)
601 struct tsl2563_chip *chip;
605 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
609 i2c_set_clientdata(client, chip);
610 chip->client = client;
612 err = tsl2563_detect(chip);
614 dev_err(&client->dev, "device not found, error %d \n", -err);
618 err = tsl2563_read_id(chip, &id);
622 mutex_init(&chip->lock);
624 /* Default values used until userspace says otherwise */
625 chip->low_thres = 0x0;
626 chip->high_thres = 0xffff;
627 chip->gainlevel = tsl2563_gainlevel_table;
628 chip->intr = TSL2563_INT_PERSIST(4);
629 chip->calib0 = calib_from_sysfs(CALIB_BASE_SYSFS);
630 chip->calib1 = calib_from_sysfs(CALIB_BASE_SYSFS);
632 dev_info(&client->dev, "model %d, rev. %d\n", id >> 4, id & 0x0f);
634 err = tsl2563_configure(chip);
638 chip->hwmon_dev = hwmon_device_register(&client->dev);
639 if (IS_ERR(chip->hwmon_dev))
642 err = tsl2563_register_sysfs(client);
644 dev_err(&client->dev, "sysfs registration failed, %d\n", err);
650 hwmon_device_unregister(chip->hwmon_dev);
656 static int tsl2563_remove(struct i2c_client *client)
658 struct tsl2563_chip *chip = i2c_get_clientdata(client);
660 tsl2563_unregister_sysfs(client);
661 hwmon_device_unregister(chip->hwmon_dev);
667 static int tsl2563_suspend(struct i2c_client *client, pm_message_t state)
669 struct tsl2563_chip *chip = i2c_get_clientdata(client);
672 mutex_lock(&chip->lock);
674 ret = tsl2563_set_power(chip, 0);
681 mutex_unlock(&chip->lock);
685 static int tsl2563_resume(struct i2c_client *client)
687 struct tsl2563_chip *chip = i2c_get_clientdata(client);
690 mutex_lock(&chip->lock);
692 ret = tsl2563_set_power(chip, 1);
696 ret = tsl2563_configure(chip);
700 chip->state.event = PM_EVENT_ON;
703 mutex_unlock(&chip->lock);
707 static const struct i2c_device_id tsl2563_id[] = {
711 MODULE_DEVICE_TABLE(i2c, tsl2563_id);
713 static struct i2c_driver tsl2563_i2c_driver = {
717 .suspend = tsl2563_suspend,
718 .resume = tsl2563_resume,
719 .probe = tsl2563_probe,
720 .remove = __devexit_p(tsl2563_remove),
721 .id_table = tsl2563_id,
724 static int __init tsl2563_init(void)
726 return i2c_add_driver(&tsl2563_i2c_driver);
729 static void __exit tsl2563_exit(void)
731 i2c_del_driver(&tsl2563_i2c_driver);
734 MODULE_AUTHOR("Nokia Corporation");
735 MODULE_DESCRIPTION("tsl2563 light sensor driver");
736 MODULE_LICENSE("GPL");
738 module_init(tsl2563_init);
739 module_exit(tsl2563_exit);