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272 lines
6.4 KiB
272 lines
6.4 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* mb1232.c - Support for MaxBotix I2CXL-MaxSonar-EZ series ultrasonic |
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* ranger with i2c interface |
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* actually tested with mb1232 type |
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* |
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* Copyright (c) 2019 Andreas Klinger <[email protected]> |
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* |
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* For details about the device see: |
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* https://www.maxbotix.com/documents/I2CXL-MaxSonar-EZ_Datasheet.pdf |
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*/ |
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#include <linux/err.h> |
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#include <linux/i2c.h> |
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#include <linux/of_irq.h> |
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#include <linux/delay.h> |
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#include <linux/module.h> |
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#include <linux/bitops.h> |
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#include <linux/iio/iio.h> |
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#include <linux/iio/sysfs.h> |
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#include <linux/iio/buffer.h> |
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#include <linux/iio/trigger_consumer.h> |
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#include <linux/iio/triggered_buffer.h> |
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/* registers of MaxSonar device */ |
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#define MB1232_RANGE_COMMAND 0x51 /* Command for reading range */ |
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#define MB1232_ADDR_UNLOCK_1 0xAA /* Command 1 for changing address */ |
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#define MB1232_ADDR_UNLOCK_2 0xA5 /* Command 2 for changing address */ |
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struct mb1232_data { |
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struct i2c_client *client; |
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struct mutex lock; |
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/* |
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* optionally a gpio can be used to announce when ranging has |
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* finished |
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* since we are just using the falling trigger of it we request |
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* only the interrupt for announcing when data is ready to be read |
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*/ |
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struct completion ranging; |
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int irqnr; |
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/* Ensure correct alignment of data to push to IIO buffer */ |
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struct { |
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s16 distance; |
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s64 ts __aligned(8); |
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} scan; |
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}; |
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static irqreturn_t mb1232_handle_irq(int irq, void *dev_id) |
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{ |
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struct iio_dev *indio_dev = dev_id; |
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struct mb1232_data *data = iio_priv(indio_dev); |
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complete(&data->ranging); |
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return IRQ_HANDLED; |
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} |
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static s16 mb1232_read_distance(struct mb1232_data *data) |
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{ |
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struct i2c_client *client = data->client; |
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int ret; |
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s16 distance; |
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__be16 buf; |
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mutex_lock(&data->lock); |
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reinit_completion(&data->ranging); |
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ret = i2c_smbus_write_byte(client, MB1232_RANGE_COMMAND); |
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if (ret < 0) { |
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dev_err(&client->dev, "write command - err: %d\n", ret); |
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goto error_unlock; |
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} |
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if (data->irqnr >= 0) { |
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/* it cannot take more than 100 ms */ |
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ret = wait_for_completion_killable_timeout(&data->ranging, |
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HZ/10); |
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if (ret < 0) |
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goto error_unlock; |
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else if (ret == 0) { |
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ret = -ETIMEDOUT; |
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goto error_unlock; |
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} |
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} else { |
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/* use simple sleep if announce irq is not connected */ |
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msleep(15); |
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} |
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ret = i2c_master_recv(client, (char *)&buf, sizeof(buf)); |
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if (ret < 0) { |
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dev_err(&client->dev, "i2c_master_recv: ret=%d\n", ret); |
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goto error_unlock; |
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} |
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distance = __be16_to_cpu(buf); |
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/* check for not returning misleading error codes */ |
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if (distance < 0) { |
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dev_err(&client->dev, "distance=%d\n", distance); |
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ret = -EINVAL; |
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goto error_unlock; |
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} |
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mutex_unlock(&data->lock); |
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return distance; |
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error_unlock: |
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mutex_unlock(&data->lock); |
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return ret; |
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} |
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static irqreturn_t mb1232_trigger_handler(int irq, void *p) |
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{ |
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struct iio_poll_func *pf = p; |
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struct iio_dev *indio_dev = pf->indio_dev; |
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struct mb1232_data *data = iio_priv(indio_dev); |
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data->scan.distance = mb1232_read_distance(data); |
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if (data->scan.distance < 0) |
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goto err; |
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iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, |
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pf->timestamp); |
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err: |
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iio_trigger_notify_done(indio_dev->trig); |
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return IRQ_HANDLED; |
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} |
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static int mb1232_read_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *channel, int *val, |
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int *val2, long mask) |
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{ |
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struct mb1232_data *data = iio_priv(indio_dev); |
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int ret; |
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if (channel->type != IIO_DISTANCE) |
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return -EINVAL; |
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switch (mask) { |
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case IIO_CHAN_INFO_RAW: |
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ret = mb1232_read_distance(data); |
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if (ret < 0) |
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return ret; |
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*val = ret; |
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return IIO_VAL_INT; |
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case IIO_CHAN_INFO_SCALE: |
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/* 1 LSB is 1 cm */ |
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*val = 0; |
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*val2 = 10000; |
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return IIO_VAL_INT_PLUS_MICRO; |
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default: |
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return -EINVAL; |
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} |
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} |
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static const struct iio_chan_spec mb1232_channels[] = { |
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{ |
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.type = IIO_DISTANCE, |
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | |
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BIT(IIO_CHAN_INFO_SCALE), |
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.scan_index = 0, |
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.scan_type = { |
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.sign = 's', |
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.realbits = 16, |
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.storagebits = 16, |
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.endianness = IIO_CPU, |
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}, |
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}, |
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IIO_CHAN_SOFT_TIMESTAMP(1), |
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}; |
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static const struct iio_info mb1232_info = { |
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.read_raw = mb1232_read_raw, |
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}; |
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static int mb1232_probe(struct i2c_client *client, |
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const struct i2c_device_id *id) |
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{ |
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struct iio_dev *indio_dev; |
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struct mb1232_data *data; |
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int ret; |
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struct device *dev = &client->dev; |
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if (!i2c_check_functionality(client->adapter, |
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I2C_FUNC_SMBUS_READ_BYTE | |
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I2C_FUNC_SMBUS_WRITE_BYTE)) |
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return -ENODEV; |
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indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); |
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if (!indio_dev) |
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return -ENOMEM; |
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data = iio_priv(indio_dev); |
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i2c_set_clientdata(client, indio_dev); |
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data->client = client; |
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indio_dev->info = &mb1232_info; |
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indio_dev->name = id->name; |
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indio_dev->modes = INDIO_DIRECT_MODE; |
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indio_dev->channels = mb1232_channels; |
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indio_dev->num_channels = ARRAY_SIZE(mb1232_channels); |
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mutex_init(&data->lock); |
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init_completion(&data->ranging); |
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data->irqnr = irq_of_parse_and_map(dev->of_node, 0); |
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if (data->irqnr <= 0) { |
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/* usage of interrupt is optional */ |
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data->irqnr = -1; |
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} else { |
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ret = devm_request_irq(dev, data->irqnr, mb1232_handle_irq, |
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IRQF_TRIGGER_FALLING, id->name, indio_dev); |
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if (ret < 0) { |
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dev_err(dev, "request_irq: %d\n", ret); |
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return ret; |
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} |
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} |
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ret = devm_iio_triggered_buffer_setup(dev, indio_dev, |
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iio_pollfunc_store_time, mb1232_trigger_handler, NULL); |
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if (ret < 0) { |
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dev_err(dev, "setup of iio triggered buffer failed\n"); |
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return ret; |
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} |
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return devm_iio_device_register(dev, indio_dev); |
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} |
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static const struct of_device_id of_mb1232_match[] = { |
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{ .compatible = "maxbotix,mb1202", }, |
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{ .compatible = "maxbotix,mb1212", }, |
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{ .compatible = "maxbotix,mb1222", }, |
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{ .compatible = "maxbotix,mb1232", }, |
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{ .compatible = "maxbotix,mb1242", }, |
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{ .compatible = "maxbotix,mb7040", }, |
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{ .compatible = "maxbotix,mb7137", }, |
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{}, |
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}; |
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MODULE_DEVICE_TABLE(of, of_mb1232_match); |
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static const struct i2c_device_id mb1232_id[] = { |
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{ "maxbotix-mb1202", }, |
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{ "maxbotix-mb1212", }, |
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{ "maxbotix-mb1222", }, |
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{ "maxbotix-mb1232", }, |
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{ "maxbotix-mb1242", }, |
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{ "maxbotix-mb7040", }, |
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{ "maxbotix-mb7137", }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(i2c, mb1232_id); |
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static struct i2c_driver mb1232_driver = { |
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.driver = { |
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.name = "maxbotix-mb1232", |
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.of_match_table = of_mb1232_match, |
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}, |
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.probe = mb1232_probe, |
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.id_table = mb1232_id, |
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}; |
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module_i2c_driver(mb1232_driver); |
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MODULE_AUTHOR("Andreas Klinger <[email protected]>"); |
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MODULE_DESCRIPTION("Maxbotix I2CXL-MaxSonar i2c ultrasonic ranger driver"); |
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MODULE_LICENSE("GPL");
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