diff options
Diffstat (limited to 'drivers/iio/light/ltr501.c')
| -rw-r--r-- | drivers/iio/light/ltr501.c | 447 |
1 files changed, 447 insertions, 0 deletions
diff --git a/drivers/iio/light/ltr501.c b/drivers/iio/light/ltr501.c new file mode 100644 index 000000000..78b87839c --- /dev/null +++ b/drivers/iio/light/ltr501.c @@ -0,0 +1,447 @@ +/* + * 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_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_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) + goto powerdown_on_error; + + ret = iio_device_register(indio_dev); + if (ret) + goto error_unreg_buffer; + + return 0; + +error_unreg_buffer: + iio_triggered_buffer_cleanup(indio_dev); +powerdown_on_error: + ltr501_powerdown(data); + return ret; +} + +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"); |