Add MaxSonar-I2CXL ultrasonic distance sensors of type family mb12x2 using the i2c interface Implemented functionality: - reading the distance via in_distance_raw - buffered mode with trigger - make use of status gpio to announce completion of ranging Signed-off-by: Andreas Klinger <ak@xxxxxxxxxxxxx> --- drivers/iio/proximity/mb12x2.c | 283 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 283 insertions(+) create mode 100644 drivers/iio/proximity/mb12x2.c diff --git a/drivers/iio/proximity/mb12x2.c b/drivers/iio/proximity/mb12x2.c new file mode 100644 index 000000000000..0c052fde94b4 --- /dev/null +++ b/drivers/iio/proximity/mb12x2.c @@ -0,0 +1,283 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * mb12x2.c - Support for I2CXL-MaxSonar-EZ series ultrasonic ranger with + * i2c interface + * actually supported are mb12x2 types + * + * Copyright (c) 2019 Andreas Klinger <ak@xxxxxxxxxxxxx> + * + * For details about the device see: + * https://www.maxbotix.com/documents/I2CXL-MaxSonar-EZ_Datasheet.pdf + * + */ + +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/gpio/consumer.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 MaxSonar device */ +#define MB12X2_RANGE_COMMAND 0x51 /* Command for reading range */ +#define MB12X2_ADDR_UNLOCK_1 0xAA /* Command 1 for changing address */ +#define MB12X2_ADDR_UNLOCK_2 0xA5 /* Command 2 for changing address */ + +struct mb12x2_data { + struct i2c_client *client; + + struct mutex lock; + + /* + * optionally a gpio can be used to announce when ranging has + * finished + */ + struct completion ranging; + struct gpio_desc *gpiod_status; + int irqnr; + + /* + * triggered buffer + * 1x16-bit channel + 3x16 padding + 4x16 timestamp + */ + s16 buffer[8]; +}; + +static irqreturn_t mb12x2_handle_irq(int irq, void *dev_id) +{ + struct iio_dev *indio_dev = dev_id; + struct mb12x2_data *data = iio_priv(indio_dev); + + /* double check to make sure data is now available */ + if (!gpiod_get_value(data->gpiod_status)) + complete(&data->ranging); + + return IRQ_HANDLED; +} + +static int mb12x2_read_distance(struct mb12x2_data *data) +{ + struct i2c_client *client = data->client; + int ret; + int distance; + unsigned char buf[2]; + + mutex_lock(&data->lock); + + reinit_completion(&data->ranging); + + ret = i2c_smbus_write_byte(client, MB12X2_RANGE_COMMAND); + if (ret < 0) { + dev_err(&client->dev, "write command - err: %d\n", ret); + mutex_unlock(&data->lock); + return ret; + } + + if (data->gpiod_status) { + /* it cannot take more than 100 ms */ + ret = wait_for_completion_killable_timeout(&data->ranging, + HZ/10); + if (ret < 0) { + mutex_unlock(&data->lock); + return ret; + } else if (ret == 0) { + mutex_unlock(&data->lock); + return -ETIMEDOUT; + } + } else { + /* + * use simple sleep if gpio announce pin is not connected + */ + msleep(15); + } + + + ret = i2c_master_recv(client, buf, sizeof(buf)); + if (ret < 0) { + dev_err(&client->dev, "i2c_master_recv: ret=%d\n", ret); + mutex_unlock(&data->lock); + return ret; + } + + distance = buf[0]<<8 | buf[1]; + + mutex_unlock(&data->lock); + + return distance; +} + +static irqreturn_t mb12x2_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct mb12x2_data *data = iio_priv(indio_dev); + s16 sensor_data; + + sensor_data = mb12x2_read_distance(data); + if (sensor_data < 0) + goto err; + + mutex_lock(&data->lock); + + data->buffer[0] = sensor_data; + iio_push_to_buffers_with_timestamp(indio_dev, + data->buffer, pf->timestamp); + + mutex_unlock(&data->lock); +err: + iio_trigger_notify_done(indio_dev->trig); + return IRQ_HANDLED; +} + +static int mb12x2_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *channel, int *val, + int *val2, long mask) +{ + struct mb12x2_data *data = iio_priv(indio_dev); + int ret; + + if (channel->type != IIO_DISTANCE) + return -EINVAL; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = mb12x2_read_distance(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 const struct iio_chan_spec mb12x2_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 mb12x2_info = { + .read_raw = mb12x2_read_raw, +}; + +static int mb12x2_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct iio_dev *indio_dev; + struct mb12x2_data *data; + int ret; + struct device *dev = &client->dev; + + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_READ_BYTE | + I2C_FUNC_SMBUS_WRITE_BYTE)) + return -ENODEV; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + + data = iio_priv(indio_dev); + i2c_set_clientdata(client, indio_dev); + data->client = client; + + indio_dev->info = &mb12x2_info; + indio_dev->name = id->name; + indio_dev->dev.parent = dev; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = mb12x2_channels; + indio_dev->num_channels = ARRAY_SIZE(mb12x2_channels); + + mutex_init(&data->lock); + + init_completion(&data->ranging); + + data->gpiod_status = devm_gpiod_get(dev, "status", GPIOD_IN); + if (IS_ERR(data->gpiod_status)) { + + if (PTR_ERR(data->gpiod_status) == -ENOENT) { + + dev_warn(dev, "no status gpio --> use sleep instead\n"); + data->gpiod_status = NULL; + } else { + + dev_err(dev, "cannot setup gpio; err=%ld\n", + PTR_ERR(data->gpiod_status)); + return PTR_ERR(data->gpiod_status); + } + } + + if (data->gpiod_status) { + + data->irqnr = gpiod_to_irq(data->gpiod_status); + if (data->irqnr < 0) { + dev_err(dev, "gpiod_to_irq: %d\n", data->irqnr); + return data->irqnr; + } + + ret = devm_request_irq(dev, data->irqnr, mb12x2_handle_irq, + IRQF_TRIGGER_FALLING, id->name, indio_dev); + if (ret < 0) { + dev_err(dev, "request_irq: %d\n", ret); + return ret; + } + } + + ret = devm_iio_triggered_buffer_setup(dev, indio_dev, + iio_pollfunc_store_time, mb12x2_trigger_handler, NULL); + if (ret < 0) { + dev_err(dev, "setup of iio triggered buffer failed\n"); + return ret; + } + + return devm_iio_device_register(dev, indio_dev); +} + +static const struct of_device_id of_mb12x2_match[] = { + { .compatible = "maxbotix,mb12x2", }, + {}, +}; + +MODULE_DEVICE_TABLE(of, of_mb12x2_match); + +static const struct i2c_device_id mb12x2_id[] = { + { "maxbotix-mb12x2", }, + { } +}; +MODULE_DEVICE_TABLE(i2c, mb12x2_id); + +static struct i2c_driver mb12x2_driver = { + .driver = { + .name = "maxbotix-mb12x2", + .of_match_table = of_mb12x2_match, + }, + .probe = mb12x2_probe, + .id_table = mb12x2_id, +}; +module_i2c_driver(mb12x2_driver); + +MODULE_AUTHOR("Andreas Klinger <ak@xxxxxxxxxxxxx>"); +MODULE_DESCRIPTION("Maxbotix I2CXL-MB12X2-EZ i2c ultrasonic ranger driver"); +MODULE_LICENSE("GPL"); -- 2.11.0
