diff options
Diffstat (limited to 'drivers/iio/light/opt3001.c')
| -rw-r--r-- | drivers/iio/light/opt3001.c | 804 |
1 files changed, 804 insertions, 0 deletions
diff --git a/drivers/iio/light/opt3001.c b/drivers/iio/light/opt3001.c new file mode 100644 index 000000000000..923aa6aef0ed --- /dev/null +++ b/drivers/iio/light/opt3001.c @@ -0,0 +1,804 @@ +/** + * opt3001.c - Texas Instruments OPT3001 Light Sensor + * + * Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com + * + * Author: Andreas Dannenberg <dannenberg@ti.com> + * Based on previous work from: Felipe Balbi <balbi@ti.com> + * + * 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 <linux/bitops.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/types.h> + +#include <linux/iio/events.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> + +#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) + +/* + * Time to wait for conversion result to be ready. The device datasheet + * worst-case max value is 880ms. Add some slack to be on the safe side. + */ +#define OPT3001_RESULT_READY_TIMEOUT msecs_to_jiffies(1000) + +struct opt3001 { + struct i2c_client *client; + struct device *dev; + + struct mutex lock; + u16 ok_to_ignore_lock:1; + u16 result_ready:1; + 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; +}; + +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; + + /* + * 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; + } + + /* Reset data-ready indicator flag (will be set in the IRQ routine) */ + opt->result_ready = false; + + /* Allow IRQ to access the device despite lock being set */ + opt->ok_to_ignore_lock = true; + + /* 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; + } + + /* Wait for the IRQ to indicate the conversion is complete */ + ret = wait_event_timeout(opt->result_ready_queue, opt->result_ready, + OPT3001_RESULT_READY_TIMEOUT); + +err: + /* 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; + + /* + * 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 100000: + reg &= ~OPT3001_CONFIGURATION_CT; + opt->int_time = 100000; + break; + case 800000: + reg |= OPT3001_CONFIGURATION_CT; + opt->int_time = 800000; + 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 = 800000; + else + opt->int_time = 100000; + + /* 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; + + 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()); + 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()); + } 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_up(&opt->result_ready_queue); + } + +out: + if (!opt->ok_to_ignore_lock) + mutex_unlock(&opt->lock); + + 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; + } + + 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; + } + + 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; + + 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" }, + { } +}; + +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), + .owner = THIS_MODULE, + }, +}; + +module_i2c_driver(opt3001_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Andreas Dannenberg <dannenberg@ti.com>"); +MODULE_DESCRIPTION("Texas Instruments OPT3001 Light Sensor Driver"); |