/*
* ltr501.c - Support for Lite-On LTR501 ambient light and proximity sensor
*
* Copyright 2014 Peter Meerwald <pmeerw@pmeerw.net>
*
* This file is subject to the terms and conditions of version 2 of
* the GNU General Public License. See the file COPYING in the main
* directory of this archive for more details.
*
* 7-bit I2C slave address 0x23
*
* TODO: interrupt, threshold, measurement rate, IR LED characteristics
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/buffer.h>
#include <linux/iio/triggered_buffer.h>
#define LTR501_DRV_NAME "ltr501"
#define LTR501_ALS_CONTR 0x80 /* ALS operation mode, SW reset */
#define LTR501_PS_CONTR 0x81 /* PS operation mode */
#define LTR501_PART_ID 0x86
#define LTR501_MANUFAC_ID 0x87
#define LTR501_ALS_DATA1 0x88 /* 16-bit, little endian */
#define LTR501_ALS_DATA0 0x8a /* 16-bit, little endian */
#define LTR501_ALS_PS_STATUS 0x8c
#define LTR501_PS_DATA 0x8d /* 16-bit, little endian */
#define LTR501_ALS_CONTR_SW_RESET BIT(2)
#define LTR501_CONTR_PS_GAIN_MASK (BIT(3) | BIT(2))
#define LTR501_CONTR_PS_GAIN_SHIFT 2
#define LTR501_CONTR_ALS_GAIN_MASK BIT(3)
#define LTR501_CONTR_ACTIVE BIT(1)
#define LTR501_STATUS_ALS_RDY BIT(2)
#define LTR501_STATUS_PS_RDY BIT(0)
#define LTR501_PS_DATA_MASK 0x7ff
struct ltr501_data {
struct i2c_client *client;
struct mutex lock_als, lock_ps;
u8 als_contr, ps_contr;
};
static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)
{
int tries = 100;
int ret;
while (tries--) {
ret = i2c_smbus_read_byte_data(data->client,
LTR501_ALS_PS_STATUS);
if (ret < 0)
return ret;
if ((ret & drdy_mask) == drdy_mask)
return 0;
msleep(25);
}
dev_err(&data->client->dev, "ltr501_drdy() failed, data not ready\n");
return -EIO;
}
static int ltr501_read_als(struct ltr501_data *data, __le16 buf[2])
{
int ret = ltr501_drdy(data, LTR501_STATUS_ALS_RDY);
if (ret < 0)
return ret;
/* always read both ALS channels in given order */
return i2c_smbus_read_i2c_block_data(data->client,
LTR501_ALS_DATA1, 2 * sizeof(__le16), (u8 *) buf);
}
static int ltr501_read_ps(struct ltr501_data *data)
{
int ret = ltr501_drdy(data, LTR501_STATUS_PS_RDY);
if (ret < 0)
return ret;
return i2c_smbus_read_word_data(data->client, LTR501_PS_DATA);
}
#define LTR501_INTENSITY_CHANNEL(_idx, _addr, _mod, _shared) { \
.type = IIO_INTENSITY, \
.modified = 1, \
.address = (_addr), \
.channel2 = (_mod), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = (_shared), \
.scan_index = (_idx), \
.scan_type = { \
.sign = 'u', \
.realbits = 16, \
.storagebits = 16, \
.endianness = IIO_CPU, \
} \
}
static const struct iio_chan_spec ltr501_channels[] = {
LTR501_INTENSITY_CHANNEL(0, LTR501_ALS_DATA0, IIO_MOD_LIGHT_BOTH, 0),
LTR501_INTENSITY_CHANNEL(1, LTR501_ALS_DATA1, IIO_MOD_LIGHT_IR,
BIT(IIO_CHAN_INFO_SCALE)),
{
.type = IIO_PROXIMITY,
.address = LTR501_PS_DATA,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE),
.scan_index = 2,
.scan_type = {
.sign = 'u',
.realbits = 11,
.storagebits = 16,
.endianness = IIO_CPU,
},
},
IIO_CHAN_SOFT_TIMESTAMP(3),
};
static const int ltr501_ps_gain[4][2] = {
{1, 0}, {0, 250000}, {0, 125000}, {0, 62500}
};
static int ltr501_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct ltr501_data *data = iio_priv(indio_dev);
__le16 buf[2];
int ret, i;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (iio_buffer_enabled(indio_dev))
return -EBUSY;
switch (chan->type) {
case IIO_INTENSITY:
mutex_lock(&data->lock_als);
ret = ltr501_read_als(data, buf);
mutex_unlock(&data->lock_als);
if (ret < 0)
return ret;
*val = le16_to_cpu(chan->address == LTR501_ALS_DATA1 ?
buf[0] : buf[1]);
return IIO_VAL_INT;
case IIO_PROXIMITY:
mutex_lock(&data->lock_ps);
ret = ltr501_read_ps(data);
mutex_unlock(&data->lock_ps);
if (ret < 0)
return ret;
*val = ret & LTR501_PS_DATA_MASK;
return IIO_VAL_INT;
default:
return -EINVAL;
}
case IIO_CHAN_INFO_SCALE:
switch (chan->type) {
case IIO_INTENSITY:
if (data->als_contr & LTR501_CONTR_ALS_GAIN_MASK) {
*val = 0;
*val2 = 5000;
return IIO_VAL_INT_PLUS_MICRO;
} else {
*val = 1;
*val2 = 0;
return IIO_VAL_INT;
}
case IIO_PROXIMITY:
i = (data->ps_contr & LTR501_CONTR_PS_GAIN_MASK) >>
LTR501_CONTR_PS_GAIN_SHIFT;
*val = ltr501_ps_gain[i][0];
*val2 = ltr501_ps_gain[i][1];
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
}
return -EINVAL;
}
static int ltr501_get_ps_gain_index(int val, int val2)
{
int i;
for (i = 0; i < ARRAY_SIZE(ltr501_ps_gain); i++)
if (val == ltr501_ps_gain[i][0] && val2 == ltr501_ps_gain[i][1])
return i;
return -1;
}
static int ltr501_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct ltr501_data *data = iio_priv(indio_dev);
int i;
if (iio_buffer_enabled(indio_dev))
return -EBUSY;
switch (mask) {
case IIO_CHAN_INFO_SCALE:
switch (chan->type) {
case IIO_INTENSITY:
if (val == 0 && val2 == 5000)
data->als_contr |= LTR501_CONTR_ALS_GAIN_MASK;
else if (val == 1 && val2 == 0)
data->als_contr &= ~LTR501_CONTR_ALS_GAIN_MASK;
else
return -EINVAL;
return i2c_smbus_write_byte_data(data->client,
LTR501_ALS_CONTR, data->als_contr);
case IIO_PROXIMITY:
i = ltr501_get_ps_gain_index(val, val2);
if (i < 0)
return -EINVAL;
data->ps_contr &= ~LTR501_CONTR_PS_GAIN_MASK;
data->ps_contr |= i << LTR501_CONTR_PS_GAIN_SHIFT;
return i2c_smbus_write_byte_data(data->client,
LTR501_PS_CONTR, data->ps_contr);
default:
return -EINVAL;
}
}
return -EINVAL;
}
static IIO_CONST_ATTR(in_proximity_scale_available, "1 0.25 0.125 0.0625");
static IIO_CONST_ATTR(in_intensity_scale_available, "1 0.005");
static struct attribute *ltr501_attributes[] = {
&iio_const_attr_in_proximity_scale_available.dev_attr.attr,
&iio_const_attr_in_intensity_scale_available.dev_attr.attr,
NULL
};
static const struct attribute_group ltr501_attribute_group = {
.attrs = ltr501_attributes,
};
static const struct iio_info ltr501_info = {
.read_raw = ltr501_read_raw,
.write_raw = ltr501_write_raw,
.attrs = <r501_attribute_group,
.driver_module = THIS_MODULE,
};
static int ltr501_write_contr(struct i2c_client *client, u8 als_val, u8 ps_val)
{
int ret = i2c_smbus_write_byte_data(client, LTR501_ALS_CONTR, als_val);
if (ret < 0)
return ret;
return i2c_smbus_write_byte_data(client, LTR501_PS_CONTR, ps_val);
}
static irqreturn_t ltr501_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct ltr501_data *data = iio_priv(indio_dev);
u16 buf[8];
__le16 als_buf[2];
u8 mask = 0;
int j = 0;
int ret;
memset(buf, 0, sizeof(buf));
/* figure out which data needs to be ready */
if (test_bit(0, indio_dev->active_scan_mask) ||
test_bit(1, indio_dev->active_scan_mask))
mask |= LTR501_STATUS_ALS_RDY;
if (test_bit(2, indio_dev->active_scan_mask))
mask |= LTR501_STATUS_PS_RDY;
ret = ltr501_drdy(data, mask);
if (ret < 0)
goto done;
if (mask & LTR501_STATUS_ALS_RDY) {
ret = i2c_smbus_read_i2c_block_data(data->client,
LTR501_ALS_DATA1, sizeof(als_buf), (u8 *) als_buf);
if (ret < 0)
return ret;
if (test_bit(0, indio_dev->active_scan_mask))
buf[j++] = le16_to_cpu(als_buf[1]);
if (test_bit(1, indio_dev->active_scan_mask))
buf[j++] = le16_to_cpu(als_buf[0]);
}
if (mask & LTR501_STATUS_PS_RDY) {
ret = i2c_smbus_read_word_data(data->client, LTR501_PS_DATA);
if (ret < 0)
goto done;
buf[j++] = ret & LTR501_PS_DATA_MASK;
}
iio_push_to_buffers_with_timestamp(indio_dev, buf,
iio_get_time_ns());
done:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static int ltr501_init(struct ltr501_data *data)
{
int ret;
ret = i2c_smbus_read_byte_data(data->client, LTR501_ALS_CONTR);
if (ret < 0)
return ret;
data->als_contr = ret | LTR501_CONTR_ACTIVE;
ret = i2c_smbus_read_byte_data(data->client, LTR501_PS_CONTR);
if (ret < 0)
return ret;
data->ps_contr = ret | LTR501_CONTR_ACTIVE;
return ltr501_write_contr(data->client, data->als_contr,
data->ps_contr);
}
static int ltr501_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct ltr501_data *data;
struct iio_dev *indio_dev;
int ret;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
data = iio_priv(indio_dev);
i2c_set_clientdata(client, indio_dev);
data->client = client;
mutex_init(&data->lock_als);
mutex_init(&data->lock_ps);
ret = i2c_smbus_read_byte_data(data->client, LTR501_PART_ID);
if (ret < 0)
return ret;
if ((ret >> 4) != 0x8)
return -ENODEV;
indio_dev->dev.parent = &client->dev;
indio_dev->info = <r501_info;
indio_dev->channels = ltr501_channels;
indio_dev->num_channels = ARRAY_SIZE(ltr501_channels);
indio_dev->name = LTR501_DRV_NAME;
indio_dev->modes = INDIO_DIRECT_MODE;
ret = ltr501_init(data);
if (ret < 0)
return ret;
ret = iio_triggered_buffer_setup(indio_dev, NULL,
ltr501_trigger_handler, NULL);
if (ret)
return ret;
ret = iio_device_register(indio_dev);
if (ret)
goto error_unreg_buffer;
return 0;
error_unreg_buffer:
iio_triggered_buffer_cleanup(indio_dev);
return ret;
}
static int ltr501_powerdown(struct ltr501_data *data)
{
return ltr501_write_contr(data->client,
data->als_contr & ~LTR501_CONTR_ACTIVE,
data->ps_contr & ~LTR501_CONTR_ACTIVE);
}
static int ltr501_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
iio_device_unregister(indio_dev);
iio_triggered_buffer_cleanup(indio_dev);
ltr501_powerdown(iio_priv(indio_dev));
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int ltr501_suspend(struct device *dev)
{
struct ltr501_data *data = iio_priv(i2c_get_clientdata(
to_i2c_client(dev)));
return ltr501_powerdown(data);
}
static int ltr501_resume(struct device *dev)
{
struct ltr501_data *data = iio_priv(i2c_get_clientdata(
to_i2c_client(dev)));
return ltr501_write_contr(data->client, data->als_contr,
data->ps_contr);
}
#endif
static SIMPLE_DEV_PM_OPS(ltr501_pm_ops, ltr501_suspend, ltr501_resume);
static const struct i2c_device_id ltr501_id[] = {
{ "ltr501", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, ltr501_id);
static struct i2c_driver ltr501_driver = {
.driver = {
.name = LTR501_DRV_NAME,
.pm = <r501_pm_ops,
.owner = THIS_MODULE,
},
.probe = ltr501_probe,
.remove = ltr501_remove,
.id_table = ltr501_id,
};
module_i2c_driver(ltr501_driver);
MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
MODULE_DESCRIPTION("Lite-On LTR501 ambient light and proximity sensor driver");
MODULE_LICENSE("GPL");