/**
* 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");