diff options
Diffstat (limited to 'drivers/iio/proximity/srf08.c')
| -rw-r--r-- | drivers/iio/proximity/srf08.c | 563 |
1 files changed, 563 insertions, 0 deletions
diff --git a/drivers/iio/proximity/srf08.c b/drivers/iio/proximity/srf08.c new file mode 100644 index 000000000..5e8d37077 --- /dev/null +++ b/drivers/iio/proximity/srf08.c @@ -0,0 +1,563 @@ +/* + * srf08.c - Support for Devantech SRFxx ultrasonic ranger + * with i2c interface + * actually supported are srf02, srf08, srf10 + * + * Copyright (c) 2016, 2017 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 + * http://www.robot-electronics.co.uk/htm/srf10tech.htm + * http://www.robot-electronics.co.uk/htm/srf02tech.htm + */ + +#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> +#include <linux/iio/buffer.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.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 */ + +enum srf08_sensor_type { + SRF02, + SRF08, + SRF10, + SRF_MAX_TYPE +}; + +struct srf08_chip_info { + const int *sensitivity_avail; + int num_sensitivity_avail; + int sensitivity_default; + + /* default value of Range in mm */ + int range_default; +}; + +struct srf08_data { + struct i2c_client *client; + + /* + * Gain in the datasheet is called sensitivity here to distinct it + * from the gain used with amplifiers of adc's + */ + int sensitivity; + + /* max. Range in mm */ + int range_mm; + struct mutex lock; + + /* Ensure timestamp is naturally aligned */ + struct { + s16 chan; + s64 timestamp __aligned(8); + } scan; + + /* Sensor-Type */ + enum srf08_sensor_type sensor_type; + + /* Chip-specific information */ + const struct srf08_chip_info *chip_info; +}; + +/* + * 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 struct srf08_chip_info srf02_chip_info = { + .sensitivity_avail = NULL, + .num_sensitivity_avail = 0, + .sensitivity_default = 0, + + .range_default = 0, +}; + +static const int srf08_sensitivity_avail[] = { + 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 const struct srf08_chip_info srf08_chip_info = { + .sensitivity_avail = srf08_sensitivity_avail, + .num_sensitivity_avail = ARRAY_SIZE(srf08_sensitivity_avail), + .sensitivity_default = 1025, + + .range_default = 6020, +}; + +static const int srf10_sensitivity_avail[] = { + 40, 40, 50, 60, 70, 80, 100, 120, + 140, 200, 250, 300, 350, 400, 500, 600, + 700, + }; + +static const struct srf08_chip_info srf10_chip_info = { + .sensitivity_avail = srf10_sensitivity_avail, + .num_sensitivity_avail = ARRAY_SIZE(srf10_sensitivity_avail), + .sensitivity_default = 700, + + .range_default = 6020, +}; + +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 irqreturn_t srf08_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct srf08_data *data = iio_priv(indio_dev); + s16 sensor_data; + + sensor_data = srf08_read_ranging(data); + if (sensor_data < 0) + goto err; + + mutex_lock(&data->lock); + + data->scan.chan = sensor_data; + iio_push_to_buffers_with_timestamp(indio_dev, + &data->scan, pf->timestamp); + + mutex_unlock(&data->lock); +err: + iio_trigger_notify_done(indio_dev->trig); + return IRQ_HANDLED; +} + +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; + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + struct srf08_data *data = iio_priv(indio_dev); + + for (i = 0; i < data->chip_info->num_sensitivity_avail; i++) + if (data->chip_info->sensitivity_avail[i]) + len += sprintf(buf + len, "%d ", + data->chip_info->sensitivity_avail[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; + + if (!val) + return -EINVAL; + + for (i = 0; i < data->chip_info->num_sensitivity_avail; i++) + if (val && (val == data->chip_info->sensitivity_avail[i])) { + regval = i; + break; + } + + if (i >= data->chip_info->num_sensitivity_avail) + 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), + .scan_index = 0, + .scan_type = { + .sign = 's', + .realbits = 16, + .storagebits = 16, + .endianness = IIO_CPU, + }, + }, + IIO_CHAN_SOFT_TIMESTAMP(1), +}; + +static const struct iio_info srf08_info = { + .read_raw = srf08_read_raw, + .attrs = &srf08_attribute_group, +}; + +/* + * srf02 don't have an adjustable range or sensitivity, + * so we don't need attributes at all + */ +static const struct iio_info srf02_info = { + .read_raw = srf08_read_raw, +}; + +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; + data->sensor_type = (enum srf08_sensor_type)id->driver_data; + + switch (data->sensor_type) { + case SRF02: + data->chip_info = &srf02_chip_info; + indio_dev->info = &srf02_info; + break; + case SRF08: + data->chip_info = &srf08_chip_info; + indio_dev->info = &srf08_info; + break; + case SRF10: + data->chip_info = &srf10_chip_info; + indio_dev->info = &srf08_info; + break; + default: + return -EINVAL; + } + + indio_dev->name = id->name; + indio_dev->dev.parent = &client->dev; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = srf08_channels; + indio_dev->num_channels = ARRAY_SIZE(srf08_channels); + + mutex_init(&data->lock); + + ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, + iio_pollfunc_store_time, srf08_trigger_handler, NULL); + if (ret < 0) { + dev_err(&client->dev, "setup of iio triggered buffer failed\n"); + return ret; + } + + if (data->chip_info->range_default) { + /* + * set default range of device in mm here + * these register values cannot be read from the hardware + * therefore set driver specific default values + * + * srf02 don't have a default value so it'll be omitted + */ + ret = srf08_write_range_mm(data, + data->chip_info->range_default); + if (ret < 0) + return ret; + } + + if (data->chip_info->sensitivity_default) { + /* + * set default sensitivity of device here + * these register values cannot be read from the hardware + * therefore set driver specific default values + * + * srf02 don't have a default value so it'll be omitted + */ + ret = srf08_write_sensitivity(data, + data->chip_info->sensitivity_default); + if (ret < 0) + return ret; + } + + return devm_iio_device_register(&client->dev, indio_dev); +} + +static const struct of_device_id of_srf08_match[] = { + { .compatible = "devantech,srf02", (void *)SRF02}, + { .compatible = "devantech,srf08", (void *)SRF08}, + { .compatible = "devantech,srf10", (void *)SRF10}, + {}, +}; + +MODULE_DEVICE_TABLE(of, of_srf08_match); + +static const struct i2c_device_id srf08_id[] = { + { "srf02", SRF02 }, + { "srf08", SRF08 }, + { "srf10", SRF10 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, srf08_id); + +static struct i2c_driver srf08_driver = { + .driver = { + .name = "srf08", + .of_match_table = of_srf08_match, + }, + .probe = srf08_probe, + .id_table = srf08_id, +}; +module_i2c_driver(srf08_driver); + +MODULE_AUTHOR("Andreas Klinger <ak@it-klinger.de>"); +MODULE_DESCRIPTION("Devantech SRF02/SRF08/SRF10 i2c ultrasonic ranger driver"); +MODULE_LICENSE("GPL"); |