> This is the IIO driver for devantech srf08 ultrasonic ranger which can be > used to measure the distances to an object. > > The sensor supports I2C with some registers.
comments below > Supported Features include: > - read the distance in ranging mode in centimeters > - output of the driver is directly the read value > - together with the scale the driver delivers the distance in meters > - only the first echo of the nearest object is delivered > - set max gain register; userspace enters analogue value > - set range registers; userspace enters range in millimeters in 43 mm steps > > Features not supported by this driver: > - ranging mode in inches or in microseconds > - ANN mode > - change I2C address through this driver > - light sensor > > The driver was added in the directory "proximity" of the iio subsystem > in absence of another directory named "distance". > There is also a new submenu "distance" > > Signed-off-by: Andreas Klinger <a...@it-klinger.de> > --- > drivers/iio/proximity/Kconfig | 15 ++ > drivers/iio/proximity/Makefile | 1 + > drivers/iio/proximity/srf08.c | 345 > +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 361 insertions(+) > create mode 100644 drivers/iio/proximity/srf08.c > > diff --git a/drivers/iio/proximity/Kconfig b/drivers/iio/proximity/Kconfig > index ef4c73db5b53..7b10a137702b 100644 > --- a/drivers/iio/proximity/Kconfig > +++ b/drivers/iio/proximity/Kconfig > @@ -46,3 +46,18 @@ config SX9500 > module will be called sx9500. > > endmenu > + > +menu "Distance sensors" > + > +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..14d8fe4e5cae 100644 > --- a/drivers/iio/proximity/Makefile > +++ b/drivers/iio/proximity/Makefile > @@ -6,3 +6,4 @@ > obj-$(CONFIG_AS3935) += as3935.o > obj-$(CONFIG_LIDAR_LITE_V2) += pulsedlight-lidar-lite-v2.o > obj-$(CONFIG_SX9500) += sx9500.o > +obj-$(CONFIG_SRF08) += srf08.o alphabethic order please > diff --git a/drivers/iio/proximity/srf08.c b/drivers/iio/proximity/srf08.c > new file mode 100644 > index 000000000000..a888a230b419 > --- /dev/null > +++ b/drivers/iio/proximity/srf08.c > @@ -0,0 +1,345 @@ > +/* > + * srf08.c - Support for Devantech SRF08 ultrasonic ranger > + * > + * Copyright (c) 2016 Andreas Klinger <a...@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 > */ Range (uppercase for consistency) > +#define SRF08_READ_ECHO_1_LOW 0x03 /* range of first echo received > */ > + > +#define SRF08_CMD_RANGING_CM 0x51 /* Ranging Mode - Result in cm */ > + > +struct srf08_data { > + struct i2c_client *client; > + int gain; /* max gain */ > + int range_mm; /* range in mm */ > + struct mutex lock; > +}; > + > +static const int srf08_gain[] = { > + 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; > + char cmd[2]; u8 or unsigned char would be cleaner, we are dealing with unsigned values or int/s32 even, see below > + int ret, i; > + > + 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; > + } > + > + /* > + * normally after 65 ms the device should have the read value > + * we round it up to 100 ms > + */ > + for (i = 0; i < 5; i++) { > + delete newline > + ret = i2c_smbus_read_byte_data(data->client, > + SRF08_READ_SW_REVISION); is reading the version really used to poll for data valid? maybe add a comment so the astute reader can lower the eyebrows > + > + /* check if a valid version number is read */ > + if ((ret < 255) && (ret > 0)) parenthesis not needed (matter of taste) > + break; > + msleep(20); > + } > + > + if ((ret >= 255) || (ret <= 0)) { > + dev_err(&client->dev, "device not ready\n"); > + mutex_unlock(&data->lock); > + return -EIO; > + } > + > + memset(cmd, 0, sizeof(cmd)); > + > + for (i = 0; i < 2; i++) { > + ret = i2c_smbus_read_byte_data(data->client, > + SRF08_READ_ECHO_1_HIGH + i); can _read_word_swapped() be used? ret is not checked for error > + cmd[i] = ret; > + } > + > + mutex_unlock(&data->lock); > + endianness conversion can be avoided using _read_word_swapped() > + return (cmd[0] << 8 | cmd[1]); > +} > + > +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); > + s32 ret; why s32 here? srf08_read_ranging() returns int > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: if (channel->type != IIO_DISTANCE) return -EINVAL; > + if (channel->type == IIO_DISTANCE) { > + ret = srf08_read_ranging(data); error check of ret missing > + *val = ret; > + } else { > + break; > + } > + return IIO_VAL_INT; > + case IIO_CHAN_INFO_SCALE: > + if (channel->type == IIO_DISTANCE) { same pattern as above; maybe use switch if you are going to add more channel types > + /* 1 LSB is 1 cm */ > + *val = 0; > + *val2 = 10000; > + } else { > + break; > + } > + return IIO_VAL_INT_PLUS_MICRO; > + default: > + break; return -EINVAL directly > + } > + > + return -EINVAL; > +} > + > +static ssize_t srf08_show_range_mm_available(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + int i, len = 0; > + > + for (i = 0; i < 256; i++) > + len += sprintf(buf + len, "%d ", (i + 1) * 43); many drivers use len += scnprintf(buf + len, PAGE_SIZE - len, ... > + > + len += sprintf(buf + len, "\n"); buf[len-1]="\n"; as most drivers do? > + > + return len; > +} > + > +static IIO_DEVICE_ATTR(range_mm_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); > + int len; > + > + len = sprintf(buf, "%d\n", data->range_mm); simply return sprintf(...) > + > + return len; > +} > + > +static ssize_t srf08_write_range_mm(struct device *dev, it's not immediately clear what this is for? > + 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); > + struct i2c_client *client = data->client; > + int ret, val; > + int regval = -1; no need to initialize regval should be u8? > + int mod; > + > + ret = kstrtoint(buf, 10, &val); kstrtouint()? > + if (ret) > + return ret; > + > + regval = val / 43 - 1; > + mod = val % 43; > + > + if (mod || (regval < 0) || (regval > 255)) > + return -EINVAL; > + > + mutex_lock(&data->lock); > + > + ret = i2c_smbus_write_byte_data(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 len; > +} > + > +static IIO_DEVICE_ATTR(range_mm, S_IRUGO | S_IWUSR, > + srf08_show_range_mm, srf08_write_range_mm, 0); > + > +static ssize_t srf08_show_gain_available(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + int i, len = 0; > + > + for (i = 0; i < ARRAY_SIZE(srf08_gain); i++) > + len += sprintf(buf + len, "%d ", srf08_gain[i]); > + > + len += sprintf(buf + len, "\n"); > + > + return len; > +} > + > +static IIO_DEVICE_ATTR(gain_available, S_IRUGO, > + srf08_show_gain_available, NULL, 0); > + > +static ssize_t srf08_show_gain(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->gain); > + > + return len; > +} > + > +static ssize_t srf08_write_gain(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); > + struct i2c_client *client = data->client; > + int ret, val, i; > + int regval = -1; u8, no init > + > + ret = kstrtoint(buf, 10, &val); kstrtouint() > + if (ret) > + return ret; > + > + for (i = 0; i < ARRAY_SIZE(srf08_gain); i++) > + if (val == srf08_gain[i]) > + regval = i; > + maybe check i >= ARRAY_SIZE instead of abusing regval > + if (regval == -1) > + return -EINVAL; > + > + mutex_lock(&data->lock); > + > + ret = i2c_smbus_write_byte_data(data->client, > + SRF08_WRITE_MAX_GAIN, regval); > + if (ret < 0) { > + dev_err(&client->dev, "write_gain - err: %d\n", ret); > + mutex_unlock(&data->lock); > + return ret; > + } > + > + data->gain = val; > + > + mutex_unlock(&data->lock); > + > + return len; > +} > + > +static IIO_DEVICE_ATTR(gain, S_IRUGO | S_IWUSR, > + srf08_show_gain, srf08_write_gain, 0); > + > +static struct attribute *srf08_attributes[] = { > + &iio_dev_attr_range_mm.dev_attr.attr, > + &iio_dev_attr_range_mm_available.dev_attr.attr, > + &iio_dev_attr_gain.dev_attr.attr, > + &iio_dev_attr_gain_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; > + > + if (!i2c_check_functionality(client->adapter, > + I2C_FUNC_SMBUS_READ_BYTE_DATA | > + I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) WORD_DATA if using word_swapped() above > + 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; > + > + /* set default values of device */ > + data->gain = 1025; use some defines, where do these magics come from? > + data->range_mm = 11008; > + > + indio_dev->name = dev_name(&client->dev); > + 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); > + > + 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 <a...@it-klinger.de>"); > +MODULE_DESCRIPTION("Devantech SRF08 ultrasonic ranger driver"); > +MODULE_LICENSE("GPL"); > -- Peter Meerwald-Stadler +43-664-2444418 (mobile)
