273 lines
6.4 KiB
C
273 lines
6.4 KiB
C
// 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 <ak@it-klinger.de>
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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 <ak@it-klinger.de>");
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MODULE_DESCRIPTION("Maxbotix I2CXL-MaxSonar i2c ultrasonic ranger driver");
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MODULE_LICENSE("GPL");
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