diff options
Diffstat (limited to 'drivers/iio')
| -rw-r--r-- | drivers/iio/proximity/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/iio/proximity/Makefile | 1 | ||||
| -rw-r--r-- | drivers/iio/proximity/srf08.c | 398 |
3 files changed, 411 insertions, 1 deletions
diff --git a/drivers/iio/proximity/Kconfig b/drivers/iio/proximity/Kconfig index ef4c73db5b53..ab96cb7a0054 100644 --- a/drivers/iio/proximity/Kconfig +++ b/drivers/iio/proximity/Kconfig @@ -18,7 +18,7 @@ config AS3935 endmenu -menu "Proximity sensors" +menu "Proximity and distance sensors" config LIDAR_LITE_V2 tristate "PulsedLight LIDAR sensor" @@ -45,4 +45,15 @@ config SX9500 To compile this driver as a module, choose M here: the module will be called sx9500. +config SRF08 + tristate "Devantech SRF08 ultrasonic ranger sensor" + depends on I2C + help + Say Y here to build a driver for Devantech SRF08 ultrasonic + ranger sensor. This driver can be used to measure the distance + of objects. + + To compile this driver as a module, choose M here: the + module will be called srf08. + endmenu diff --git a/drivers/iio/proximity/Makefile b/drivers/iio/proximity/Makefile index 9aadd9a8ee99..e914c2a5dd49 100644 --- a/drivers/iio/proximity/Makefile +++ b/drivers/iio/proximity/Makefile @@ -5,4 +5,5 @@ # When adding new entries keep the list in alphabetical order obj-$(CONFIG_AS3935) += as3935.o obj-$(CONFIG_LIDAR_LITE_V2) += pulsedlight-lidar-lite-v2.o +obj-$(CONFIG_SRF08) += srf08.o obj-$(CONFIG_SX9500) += sx9500.o diff --git a/drivers/iio/proximity/srf08.c b/drivers/iio/proximity/srf08.c new file mode 100644 index 000000000000..49316cbf7c60 --- /dev/null +++ b/drivers/iio/proximity/srf08.c @@ -0,0 +1,398 @@ +/* + * srf08.c - Support for Devantech SRF08 ultrasonic ranger + * + * Copyright (c) 2016 Andreas Klinger <ak@it-klinger.de> + * + * 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. + * + * For details about the device see: + * http://www.robot-electronics.co.uk/htm/srf08tech.html + */ + +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/delay.h> +#include <linux/module.h> +#include <linux/bitops.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> + +/* registers of SRF08 device */ +#define SRF08_WRITE_COMMAND 0x00 /* Command Register */ +#define SRF08_WRITE_MAX_GAIN 0x01 /* Max Gain Register: 0 .. 31 */ +#define SRF08_WRITE_RANGE 0x02 /* Range Register: 0 .. 255 */ +#define SRF08_READ_SW_REVISION 0x00 /* Software Revision */ +#define SRF08_READ_LIGHT 0x01 /* Light Sensor during last echo */ +#define SRF08_READ_ECHO_1_HIGH 0x02 /* Range of first echo received */ +#define SRF08_READ_ECHO_1_LOW 0x03 /* Range of first echo received */ + +#define SRF08_CMD_RANGING_CM 0x51 /* Ranging Mode - Result in cm */ + +#define SRF08_DEFAULT_GAIN 1025 /* default analogue value of Gain */ +#define SRF08_DEFAULT_RANGE 6020 /* default value of Range in mm */ + +struct srf08_data { + struct i2c_client *client; + int sensitivity; /* Gain */ + int range_mm; /* max. Range in mm */ + struct mutex lock; +}; + +/* + * in the documentation one can read about the "Gain" of the device + * which is used here for amplifying the signal and filtering out unwanted + * ones. + * But with ADC's this term is already used differently and that's why it + * is called "Sensitivity" here. + */ +static const int srf08_sensitivity[] = { + 94, 97, 100, 103, 107, 110, 114, 118, + 123, 128, 133, 139, 145, 152, 159, 168, + 177, 187, 199, 212, 227, 245, 265, 288, + 317, 352, 395, 450, 524, 626, 777, 1025 }; + +static int srf08_read_ranging(struct srf08_data *data) +{ + struct i2c_client *client = data->client; + int ret, i; + int waittime; + + mutex_lock(&data->lock); + + ret = i2c_smbus_write_byte_data(data->client, + SRF08_WRITE_COMMAND, SRF08_CMD_RANGING_CM); + if (ret < 0) { + dev_err(&client->dev, "write command - err: %d\n", ret); + mutex_unlock(&data->lock); + return ret; + } + + /* + * we read here until a correct version number shows up as + * suggested by the documentation + * + * with an ultrasonic speed of 343 m/s and a roundtrip of it + * sleep the expected duration and try to read from the device + * if nothing useful is read try it in a shorter grid + * + * polling for not more than 20 ms should be enough + */ + waittime = 1 + data->range_mm / 172; + msleep(waittime); + for (i = 0; i < 4; i++) { + ret = i2c_smbus_read_byte_data(data->client, + SRF08_READ_SW_REVISION); + + /* check if a valid version number is read */ + if (ret < 255 && ret > 0) + break; + msleep(5); + } + + if (ret >= 255 || ret <= 0) { + dev_err(&client->dev, "device not ready\n"); + mutex_unlock(&data->lock); + return -EIO; + } + + ret = i2c_smbus_read_word_swapped(data->client, + SRF08_READ_ECHO_1_HIGH); + if (ret < 0) { + dev_err(&client->dev, "cannot read distance: ret=%d\n", ret); + mutex_unlock(&data->lock); + return ret; + } + + mutex_unlock(&data->lock); + + return ret; +} + +static int srf08_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *channel, int *val, + int *val2, long mask) +{ + struct srf08_data *data = iio_priv(indio_dev); + int ret; + + if (channel->type != IIO_DISTANCE) + return -EINVAL; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = srf08_read_ranging(data); + if (ret < 0) + return ret; + *val = ret; + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + /* 1 LSB is 1 cm */ + *val = 0; + *val2 = 10000; + return IIO_VAL_INT_PLUS_MICRO; + default: + return -EINVAL; + } +} + +static ssize_t srf08_show_range_mm_available(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "[0.043 0.043 11.008]\n"); +} + +static IIO_DEVICE_ATTR(sensor_max_range_available, S_IRUGO, + srf08_show_range_mm_available, NULL, 0); + +static ssize_t srf08_show_range_mm(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + struct srf08_data *data = iio_priv(indio_dev); + + return sprintf(buf, "%d.%03d\n", data->range_mm / 1000, + data->range_mm % 1000); +} + +/* + * set the range of the sensor to an even multiple of 43 mm + * which corresponds to 1 LSB in the register + * + * register value corresponding range + * 0x00 43 mm + * 0x01 86 mm + * 0x02 129 mm + * ... + * 0xFF 11008 mm + */ +static ssize_t srf08_write_range_mm(struct srf08_data *data, unsigned int val) +{ + int ret; + struct i2c_client *client = data->client; + unsigned int mod; + u8 regval; + + ret = val / 43 - 1; + mod = val % 43; + + if (mod || (ret < 0) || (ret > 255)) + return -EINVAL; + + regval = ret; + + mutex_lock(&data->lock); + + ret = i2c_smbus_write_byte_data(client, SRF08_WRITE_RANGE, regval); + if (ret < 0) { + dev_err(&client->dev, "write_range - err: %d\n", ret); + mutex_unlock(&data->lock); + return ret; + } + + data->range_mm = val; + + mutex_unlock(&data->lock); + + return 0; +} + +static ssize_t srf08_store_range_mm(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + struct srf08_data *data = iio_priv(indio_dev); + int ret; + int integer, fract; + + ret = iio_str_to_fixpoint(buf, 100, &integer, &fract); + if (ret) + return ret; + + ret = srf08_write_range_mm(data, integer * 1000 + fract); + if (ret < 0) + return ret; + + return len; +} + +static IIO_DEVICE_ATTR(sensor_max_range, S_IRUGO | S_IWUSR, + srf08_show_range_mm, srf08_store_range_mm, 0); + +static ssize_t srf08_show_sensitivity_available(struct device *dev, + struct device_attribute *attr, char *buf) +{ + int i, len = 0; + + for (i = 0; i < ARRAY_SIZE(srf08_sensitivity); i++) + len += sprintf(buf + len, "%d ", srf08_sensitivity[i]); + + len += sprintf(buf + len, "\n"); + + return len; +} + +static IIO_DEVICE_ATTR(sensor_sensitivity_available, S_IRUGO, + srf08_show_sensitivity_available, NULL, 0); + +static ssize_t srf08_show_sensitivity(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + struct srf08_data *data = iio_priv(indio_dev); + int len; + + len = sprintf(buf, "%d\n", data->sensitivity); + + return len; +} + +static ssize_t srf08_write_sensitivity(struct srf08_data *data, + unsigned int val) +{ + struct i2c_client *client = data->client; + int ret, i; + u8 regval; + + for (i = 0; i < ARRAY_SIZE(srf08_sensitivity); i++) + if (val == srf08_sensitivity[i]) { + regval = i; + break; + } + + if (i >= ARRAY_SIZE(srf08_sensitivity)) + return -EINVAL; + + mutex_lock(&data->lock); + + ret = i2c_smbus_write_byte_data(client, + SRF08_WRITE_MAX_GAIN, regval); + if (ret < 0) { + dev_err(&client->dev, "write_sensitivity - err: %d\n", ret); + mutex_unlock(&data->lock); + return ret; + } + + data->sensitivity = val; + + mutex_unlock(&data->lock); + + return 0; +} + +static ssize_t srf08_store_sensitivity(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + struct srf08_data *data = iio_priv(indio_dev); + int ret; + unsigned int val; + + ret = kstrtouint(buf, 10, &val); + if (ret) + return ret; + + ret = srf08_write_sensitivity(data, val); + if (ret < 0) + return ret; + + return len; +} + +static IIO_DEVICE_ATTR(sensor_sensitivity, S_IRUGO | S_IWUSR, + srf08_show_sensitivity, srf08_store_sensitivity, 0); + +static struct attribute *srf08_attributes[] = { + &iio_dev_attr_sensor_max_range.dev_attr.attr, + &iio_dev_attr_sensor_max_range_available.dev_attr.attr, + &iio_dev_attr_sensor_sensitivity.dev_attr.attr, + &iio_dev_attr_sensor_sensitivity_available.dev_attr.attr, + NULL, +}; + +static const struct attribute_group srf08_attribute_group = { + .attrs = srf08_attributes, +}; + +static const struct iio_chan_spec srf08_channels[] = { + { + .type = IIO_DISTANCE, + .info_mask_separate = + BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + }, +}; + +static const struct iio_info srf08_info = { + .read_raw = srf08_read_raw, + .attrs = &srf08_attribute_group, + .driver_module = THIS_MODULE, +}; + +static int srf08_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct iio_dev *indio_dev; + struct srf08_data *data; + int ret; + + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_READ_BYTE_DATA | + I2C_FUNC_SMBUS_WRITE_BYTE_DATA | + I2C_FUNC_SMBUS_READ_WORD_DATA)) + return -ENODEV; + + 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; + + indio_dev->name = "srf08"; + indio_dev->dev.parent = &client->dev; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->info = &srf08_info; + indio_dev->channels = srf08_channels; + indio_dev->num_channels = ARRAY_SIZE(srf08_channels); + + mutex_init(&data->lock); + + /* + * set default values of device here + * these register values cannot be read from the hardware + * therefore set driver specific default values + */ + ret = srf08_write_range_mm(data, SRF08_DEFAULT_RANGE); + if (ret < 0) + return ret; + + ret = srf08_write_sensitivity(data, SRF08_DEFAULT_GAIN); + if (ret < 0) + return ret; + + return devm_iio_device_register(&client->dev, indio_dev); +} + +static const struct i2c_device_id srf08_id[] = { + { "srf08", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, srf08_id); + +static struct i2c_driver srf08_driver = { + .driver = { + .name = "srf08", + }, + .probe = srf08_probe, + .id_table = srf08_id, +}; +module_i2c_driver(srf08_driver); + +MODULE_AUTHOR("Andreas Klinger <ak@it-klinger.de>"); +MODULE_DESCRIPTION("Devantech SRF08 ultrasonic ranger driver"); +MODULE_LICENSE("GPL"); |