/** * opt3001.c - Texas Instruments OPT3001 Light Sensor * * Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com * * Author: Andreas Dannenberg * Based on previous work from: Felipe Balbi * * This program is free software: you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 of the License * as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define OPT3001_RESULT 0x00 #define OPT3001_CONFIGURATION 0x01 #define OPT3001_LOW_LIMIT 0x02 #define OPT3001_HIGH_LIMIT 0x03 #define OPT3001_MANUFACTURER_ID 0x7e #define OPT3001_DEVICE_ID 0x7f #define OPT3001_CONFIGURATION_RN_MASK (0xf << 12) #define OPT3001_CONFIGURATION_RN_AUTO (0xc << 12) #define OPT3001_CONFIGURATION_CT BIT(11) #define OPT3001_CONFIGURATION_M_MASK (3 << 9) #define OPT3001_CONFIGURATION_M_SHUTDOWN (0 << 9) #define OPT3001_CONFIGURATION_M_SINGLE (1 << 9) #define OPT3001_CONFIGURATION_M_CONTINUOUS (2 << 9) /* also 3 << 9 */ #define OPT3001_CONFIGURATION_OVF BIT(8) #define OPT3001_CONFIGURATION_CRF BIT(7) #define OPT3001_CONFIGURATION_FH BIT(6) #define OPT3001_CONFIGURATION_FL BIT(5) #define OPT3001_CONFIGURATION_L BIT(4) #define OPT3001_CONFIGURATION_POL BIT(3) #define OPT3001_CONFIGURATION_ME BIT(2) #define OPT3001_CONFIGURATION_FC_MASK (3 << 0) /* The end-of-conversion enable is located in the low-limit register */ #define OPT3001_LOW_LIMIT_EOC_ENABLE 0xc000 #define OPT3001_REG_EXPONENT(n) ((n) >> 12) #define OPT3001_REG_MANTISSA(n) ((n) & 0xfff) #define OPT3001_INT_TIME_LONG 800000 #define OPT3001_INT_TIME_SHORT 100000 /* * Time to wait for conversion result to be ready. The device datasheet * sect. 6.5 states results are ready after total integration time plus 3ms. * This results in worst-case max values of 113ms or 883ms, respectively. * Add some slack to be on the safe side. */ #define OPT3001_RESULT_READY_SHORT 150 #define OPT3001_RESULT_READY_LONG 1000 struct opt3001 { struct i2c_client *client; struct device *dev; struct mutex lock; bool ok_to_ignore_lock; bool result_ready; wait_queue_head_t result_ready_queue; u16 result; u32 int_time; u32 mode; u16 high_thresh_mantissa; u16 low_thresh_mantissa; u8 high_thresh_exp; u8 low_thresh_exp; bool use_irq; }; struct opt3001_scale { int val; int val2; }; static const struct opt3001_scale opt3001_scales[] = { { .val = 40, .val2 = 950000, }, { .val = 81, .val2 = 900000, }, { .val = 163, .val2 = 800000, }, { .val = 327, .val2 = 600000, }, { .val = 655, .val2 = 200000, }, { .val = 1310, .val2 = 400000, }, { .val = 2620, .val2 = 800000, }, { .val = 5241, .val2 = 600000, }, { .val = 10483, .val2 = 200000, }, { .val = 20966, .val2 = 400000, }, { .val = 83865, .val2 = 600000, }, }; static int opt3001_find_scale(const struct opt3001 *opt, int val, int val2, u8 *exponent) { int i; for (i = 0; i < ARRAY_SIZE(opt3001_scales); i++) { const struct opt3001_scale *scale = &opt3001_scales[i]; /* * Combine the integer and micro parts for comparison * purposes. Use milli lux precision to avoid 32-bit integer * overflows. */ if ((val * 1000 + val2 / 1000) <= (scale->val * 1000 + scale->val2 / 1000)) { *exponent = i; return 0; } } return -EINVAL; } static void opt3001_to_iio_ret(struct opt3001 *opt, u8 exponent, u16 mantissa, int *val, int *val2) { int lux; lux = 10 * (mantissa << exponent); *val = lux / 1000; *val2 = (lux - (*val * 1000)) * 1000; } static void opt3001_set_mode(struct opt3001 *opt, u16 *reg, u16 mode) { *reg &= ~OPT3001_CONFIGURATION_M_MASK; *reg |= mode; opt->mode = mode; } static IIO_CONST_ATTR_INT_TIME_AVAIL("0.1 0.8"); static struct attribute *opt3001_attributes[] = { &iio_const_attr_integration_time_available.dev_attr.attr, NULL }; static const struct attribute_group opt3001_attribute_group = { .attrs = opt3001_attributes, }; static const struct iio_event_spec opt3001_event_spec[] = { { .type = IIO_EV_TYPE_THRESH, .dir = IIO_EV_DIR_RISING, .mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE), }, { .type = IIO_EV_TYPE_THRESH, .dir = IIO_EV_DIR_FALLING, .mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE), }, }; static const struct iio_chan_spec opt3001_channels[] = { { .type = IIO_LIGHT, .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | BIT(IIO_CHAN_INFO_INT_TIME), .event_spec = opt3001_event_spec, .num_event_specs = ARRAY_SIZE(opt3001_event_spec), }, IIO_CHAN_SOFT_TIMESTAMP(1), }; static int opt3001_get_lux(struct opt3001 *opt, int *val, int *val2) { int ret; u16 mantissa; u16 reg; u8 exponent; u16 value; long timeout; if (opt->use_irq) { /* * Enable the end-of-conversion interrupt mechanism. Note that * doing so will overwrite the low-level limit value however we * will restore this value later on. */ ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_LOW_LIMIT, OPT3001_LOW_LIMIT_EOC_ENABLE); if (ret < 0) { dev_err(opt->dev, "failed to write register %02x\n", OPT3001_LOW_LIMIT); return ret; } /* Allow IRQ to access the device despite lock being set */ opt->ok_to_ignore_lock = true; } /* Reset data-ready indicator flag */ opt->result_ready = false; /* Configure for single-conversion mode and start a new conversion */ ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION); if (ret < 0) { dev_err(opt->dev, "failed to read register %02x\n", OPT3001_CONFIGURATION); goto err; } reg = ret; opt3001_set_mode(opt, ®, OPT3001_CONFIGURATION_M_SINGLE); ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION, reg); if (ret < 0) { dev_err(opt->dev, "failed to write register %02x\n", OPT3001_CONFIGURATION); goto err; } if (opt->use_irq) { /* Wait for the IRQ to indicate the conversion is complete */ ret = wait_event_timeout(opt->result_ready_queue, opt->result_ready, msecs_to_jiffies(OPT3001_RESULT_READY_LONG)); } else { /* Sleep for result ready time */ timeout = (opt->int_time == OPT3001_INT_TIME_SHORT) ? OPT3001_RESULT_READY_SHORT : OPT3001_RESULT_READY_LONG; msleep(timeout); /* Check result ready flag */ ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION); if (ret < 0) { dev_err(opt->dev, "failed to read register %02x\n", OPT3001_CONFIGURATION); goto err; } if (!(ret & OPT3001_CONFIGURATION_CRF)) { ret = -ETIMEDOUT; goto err; } /* Obtain value */ ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_RESULT); if (ret < 0) { dev_err(opt->dev, "failed to read register %02x\n", OPT3001_RESULT); goto err; } opt->result = ret; opt->result_ready = true; } err: if (opt->use_irq) /* Disallow IRQ to access the device while lock is active */ opt->ok_to_ignore_lock = false; if (ret == 0) return -ETIMEDOUT; else if (ret < 0) return ret; if (opt->use_irq) { /* * Disable the end-of-conversion interrupt mechanism by * restoring the low-level limit value (clearing * OPT3001_LOW_LIMIT_EOC_ENABLE). Note that selectively clearing * those enable bits would affect the actual limit value due to * bit-overlap and therefore can't be done. */ value = (opt->low_thresh_exp << 12) | opt->low_thresh_mantissa; ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_LOW_LIMIT, value); if (ret < 0) { dev_err(opt->dev, "failed to write register %02x\n", OPT3001_LOW_LIMIT); return ret; } } exponent = OPT3001_REG_EXPONENT(opt->result); mantissa = OPT3001_REG_MANTISSA(opt->result); opt3001_to_iio_ret(opt, exponent, mantissa, val, val2); return IIO_VAL_INT_PLUS_MICRO; } static int opt3001_get_int_time(struct opt3001 *opt, int *val, int *val2) { *val = 0; *val2 = opt->int_time; return IIO_VAL_INT_PLUS_MICRO; } static int opt3001_set_int_time(struct opt3001 *opt, int time) { int ret; u16 reg; ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION); if (ret < 0) { dev_err(opt->dev, "failed to read register %02x\n", OPT3001_CONFIGURATION); return ret; } reg = ret; switch (time) { case OPT3001_INT_TIME_SHORT: reg &= ~OPT3001_CONFIGURATION_CT; opt->int_time = OPT3001_INT_TIME_SHORT; break; case OPT3001_INT_TIME_LONG: reg |= OPT3001_CONFIGURATION_CT; opt->int_time = OPT3001_INT_TIME_LONG; break; default: return -EINVAL; } return i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION, reg); } static int opt3001_read_raw(struct iio_dev *iio, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct opt3001 *opt = iio_priv(iio); int ret; if (opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS) return -EBUSY; if (chan->type != IIO_LIGHT) return -EINVAL; mutex_lock(&opt->lock); switch (mask) { case IIO_CHAN_INFO_PROCESSED: ret = opt3001_get_lux(opt, val, val2); break; case IIO_CHAN_INFO_INT_TIME: ret = opt3001_get_int_time(opt, val, val2); break; default: ret = -EINVAL; } mutex_unlock(&opt->lock); return ret; } static int opt3001_write_raw(struct iio_dev *iio, struct iio_chan_spec const *chan, int val, int val2, long mask) { struct opt3001 *opt = iio_priv(iio); int ret; if (opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS) return -EBUSY; if (chan->type != IIO_LIGHT) return -EINVAL; if (mask != IIO_CHAN_INFO_INT_TIME) return -EINVAL; if (val != 0) return -EINVAL; mutex_lock(&opt->lock); ret = opt3001_set_int_time(opt, val2); mutex_unlock(&opt->lock); return ret; } static int opt3001_read_event_value(struct iio_dev *iio, const struct iio_chan_spec *chan, enum iio_event_type type, enum iio_event_direction dir, enum iio_event_info info, int *val, int *val2) { struct opt3001 *opt = iio_priv(iio); int ret = IIO_VAL_INT_PLUS_MICRO; mutex_lock(&opt->lock); switch (dir) { case IIO_EV_DIR_RISING: opt3001_to_iio_ret(opt, opt->high_thresh_exp, opt->high_thresh_mantissa, val, val2); break; case IIO_EV_DIR_FALLING: opt3001_to_iio_ret(opt, opt->low_thresh_exp, opt->low_thresh_mantissa, val, val2); break; default: ret = -EINVAL; } mutex_unlock(&opt->lock); return ret; } static int opt3001_write_event_value(struct iio_dev *iio, const struct iio_chan_spec *chan, enum iio_event_type type, enum iio_event_direction dir, enum iio_event_info info, int val, int val2) { struct opt3001 *opt = iio_priv(iio); int ret; u16 mantissa; u16 value; u16 reg; u8 exponent; if (val < 0) return -EINVAL; mutex_lock(&opt->lock); ret = opt3001_find_scale(opt, val, val2, &exponent); if (ret < 0) { dev_err(opt->dev, "can't find scale for %d.%06u\n", val, val2); goto err; } mantissa = (((val * 1000) + (val2 / 1000)) / 10) >> exponent; value = (exponent << 12) | mantissa; switch (dir) { case IIO_EV_DIR_RISING: reg = OPT3001_HIGH_LIMIT; opt->high_thresh_mantissa = mantissa; opt->high_thresh_exp = exponent; break; case IIO_EV_DIR_FALLING: reg = OPT3001_LOW_LIMIT; opt->low_thresh_mantissa = mantissa; opt->low_thresh_exp = exponent; break; default: ret = -EINVAL; goto err; } ret = i2c_smbus_write_word_swapped(opt->client, reg, value); if (ret < 0) { dev_err(opt->dev, "failed to write register %02x\n", reg); goto err; } err: mutex_unlock(&opt->lock); return ret; } static int opt3001_read_event_config(struct iio_dev *iio, const struct iio_chan_spec *chan, enum iio_event_type type, enum iio_event_direction dir) { struct opt3001 *opt = iio_priv(iio); return opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS; } static int opt3001_write_event_config(struct iio_dev *iio, const struct iio_chan_spec *chan, enum iio_event_type type, enum iio_event_direction dir, int state) { struct opt3001 *opt = iio_priv(iio); int ret; u16 mode; u16 reg; if (state && opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS) return 0; if (!state && opt->mode == OPT3001_CONFIGURATION_M_SHUTDOWN) return 0; mutex_lock(&opt->lock); mode = state ? OPT3001_CONFIGURATION_M_CONTINUOUS : OPT3001_CONFIGURATION_M_SHUTDOWN; ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION); if (ret < 0) { dev_err(opt->dev, "failed to read register %02x\n", OPT3001_CONFIGURATION); goto err; } reg = ret; opt3001_set_mode(opt, ®, mode); ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION, reg); if (ret < 0) { dev_err(opt->dev, "failed to write register %02x\n", OPT3001_CONFIGURATION); goto err; } err: mutex_unlock(&opt->lock); return ret; } static const struct iio_info opt3001_info = { .driver_module = THIS_MODULE, .attrs = &opt3001_attribute_group, .read_raw = opt3001_read_raw, .write_raw = opt3001_write_raw, .read_event_value = opt3001_read_event_value, .write_event_value = opt3001_write_event_value, .read_event_config = opt3001_read_event_config, .write_event_config = opt3001_write_event_config, }; static int opt3001_read_id(struct opt3001 *opt) { char manufacturer[2]; u16 device_id; int ret; ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_MANUFACTURER_ID); if (ret < 0) { dev_err(opt->dev, "failed to read register %02x\n", OPT3001_MANUFACTURER_ID); return ret; } manufacturer[0] = ret >> 8; manufacturer[1] = ret & 0xff; ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_DEVICE_ID); if (ret < 0) { dev_err(opt->dev, "failed to read register %02x\n", OPT3001_DEVICE_ID); return ret; } device_id = ret; dev_info(opt->dev, "Found %c%c OPT%04x\n", manufacturer[0], manufacturer[1], device_id); return 0; } static int opt3001_configure(struct opt3001 *opt) { int ret; u16 reg; ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION); if (ret < 0) { dev_err(opt->dev, "failed to read register %02x\n", OPT3001_CONFIGURATION); return ret; } reg = ret; /* Enable automatic full-scale setting mode */ reg &= ~OPT3001_CONFIGURATION_RN_MASK; reg |= OPT3001_CONFIGURATION_RN_AUTO; /* Reflect status of the device's integration time setting */ if (reg & OPT3001_CONFIGURATION_CT) opt->int_time = OPT3001_INT_TIME_LONG; else opt->int_time = OPT3001_INT_TIME_SHORT; /* Ensure device is in shutdown initially */ opt3001_set_mode(opt, ®, OPT3001_CONFIGURATION_M_SHUTDOWN); /* Configure for latched window-style comparison operation */ reg |= OPT3001_CONFIGURATION_L; reg &= ~OPT3001_CONFIGURATION_POL; reg &= ~OPT3001_CONFIGURATION_ME; reg &= ~OPT3001_CONFIGURATION_FC_MASK; ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION, reg); if (ret < 0) { dev_err(opt->dev, "failed to write register %02x\n", OPT3001_CONFIGURATION); return ret; } ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_LOW_LIMIT); if (ret < 0) { dev_err(opt->dev, "failed to read register %02x\n", OPT3001_LOW_LIMIT); return ret; } opt->low_thresh_mantissa = OPT3001_REG_MANTISSA(ret); opt->low_thresh_exp = OPT3001_REG_EXPONENT(ret); ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_HIGH_LIMIT); if (ret < 0) { dev_err(opt->dev, "failed to read register %02x\n", OPT3001_HIGH_LIMIT); return ret; } opt->high_thresh_mantissa = OPT3001_REG_MANTISSA(ret); opt->high_thresh_exp = OPT3001_REG_EXPONENT(ret); return 0; } static irqreturn_t opt3001_irq(int irq, void *_iio) { struct iio_dev *iio = _iio; struct opt3001 *opt = iio_priv(iio); int ret; bool wake_result_ready_queue = false; if (!opt->ok_to_ignore_lock) mutex_lock(&opt->lock); ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION); if (ret < 0) { dev_err(opt->dev, "failed to read register %02x\n", OPT3001_CONFIGURATION); goto out; } if ((ret & OPT3001_CONFIGURATION_M_MASK) == OPT3001_CONFIGURATION_M_CONTINUOUS) { if (ret & OPT3001_CONFIGURATION_FH) iio_push_event(iio, IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0, IIO_EV_TYPE_THRESH, IIO_EV_DIR_RISING), iio_get_time_ns(iio)); if (ret & OPT3001_CONFIGURATION_FL) iio_push_event(iio, IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0, IIO_EV_TYPE_THRESH, IIO_EV_DIR_FALLING), iio_get_time_ns(iio)); } else if (ret & OPT3001_CONFIGURATION_CRF) { ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_RESULT); if (ret < 0) { dev_err(opt->dev, "failed to read register %02x\n", OPT3001_RESULT); goto out; } opt->result = ret; opt->result_ready = true; wake_result_ready_queue = true; } out: if (!opt->ok_to_ignore_lock) mutex_unlock(&opt->lock); if (wake_result_ready_queue) wake_up(&opt->result_ready_queue); return IRQ_HANDLED; } static int opt3001_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct device *dev = &client->dev; struct iio_dev *iio; struct opt3001 *opt; int irq = client->irq; int ret; iio = devm_iio_device_alloc(dev, sizeof(*opt)); if (!iio) return -ENOMEM; opt = iio_priv(iio); opt->client = client; opt->dev = dev; mutex_init(&opt->lock); init_waitqueue_head(&opt->result_ready_queue); i2c_set_clientdata(client, iio); ret = opt3001_read_id(opt); if (ret) return ret; ret = opt3001_configure(opt); if (ret) return ret; iio->name = client->name; iio->channels = opt3001_channels; iio->num_channels = ARRAY_SIZE(opt3001_channels); iio->dev.parent = dev; iio->modes = INDIO_DIRECT_MODE; iio->info = &opt3001_info; ret = devm_iio_device_register(dev, iio); if (ret) { dev_err(dev, "failed to register IIO device\n"); return ret; } /* Make use of INT pin only if valid IRQ no. is given */ if (irq > 0) { ret = request_threaded_irq(irq, NULL, opt3001_irq, IRQF_TRIGGER_FALLING | IRQF_ONESHOT, "opt3001", iio); if (ret) { dev_err(dev, "failed to request IRQ #%d\n", irq); return ret; } opt->use_irq = true; } else { dev_dbg(opt->dev, "enabling interrupt-less operation\n"); } return 0; } static int opt3001_remove(struct i2c_client *client) { struct iio_dev *iio = i2c_get_clientdata(client); struct opt3001 *opt = iio_priv(iio); int ret; u16 reg; if (opt->use_irq) free_irq(client->irq, iio); ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION); if (ret < 0) { dev_err(opt->dev, "failed to read register %02x\n", OPT3001_CONFIGURATION); return ret; } reg = ret; opt3001_set_mode(opt, ®, OPT3001_CONFIGURATION_M_SHUTDOWN); ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION, reg); if (ret < 0) { dev_err(opt->dev, "failed to write register %02x\n", OPT3001_CONFIGURATION); return ret; } return 0; } static const struct i2c_device_id opt3001_id[] = { { "opt3001", 0 }, { } /* Terminating Entry */ }; MODULE_DEVICE_TABLE(i2c, opt3001_id); static const struct of_device_id opt3001_of_match[] = { { .compatible = "ti,opt3001" }, { } }; MODULE_DEVICE_TABLE(of, opt3001_of_match); static struct i2c_driver opt3001_driver = { .probe = opt3001_probe, .remove = opt3001_remove, .id_table = opt3001_id, .driver = { .name = "opt3001", .of_match_table = of_match_ptr(opt3001_of_match), }, }; module_i2c_driver(opt3001_driver); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Andreas Dannenberg "); MODULE_DESCRIPTION("Texas Instruments OPT3001 Light Sensor Driver");