// SPDX-License-Identifier: GPL-2.0+
/*
* mb1232.c - Support for MaxBotix I2CXL-MaxSonar-EZ series ultrasonic
* ranger with i2c interface
* actually tested with mb1232 type
*
* Copyright (c) 2019 Andreas Klinger <[email protected]>
*
* For details about the device see:
* https://www.maxbotix.com/documents/I2CXL-MaxSonar-EZ_Datasheet.pdf
*/
#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/property.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 MB1232_RANGE_COMMAND 0x51 /* Command for reading range */
#define MB1232_ADDR_UNLOCK_1 0xAA /* Command 1 for changing address */
#define MB1232_ADDR_UNLOCK_2 0xA5 /* Command 2 for changing address */
struct mb1232_data {
struct i2c_client *client;
struct mutex lock;
/*
* optionally a gpio can be used to announce when ranging has
* finished
* since we are just using the falling trigger of it we request
* only the interrupt for announcing when data is ready to be read
*/
struct completion ranging;
int irqnr;
/* Ensure correct alignment of data to push to IIO buffer */
struct {
s16 distance;
s64 ts __aligned(8);
} scan;
};
static irqreturn_t mb1232_handle_irq(int irq, void *dev_id)
{
struct iio_dev *indio_dev = dev_id;
struct mb1232_data *data = iio_priv(indio_dev);
complete(&data->ranging);
return IRQ_HANDLED;
}
static s16 mb1232_read_distance(struct mb1232_data *data)
{
struct i2c_client *client = data->client;
int ret;
s16 distance;
__be16 buf;
mutex_lock(&data->lock);
reinit_completion(&data->ranging);
ret = i2c_smbus_write_byte(client, MB1232_RANGE_COMMAND);
if (ret < 0) {
dev_err(&client->dev, "write command - err: %d\n", ret);
goto error_unlock;
}
if (data->irqnr > 0) {
/* it cannot take more than 100 ms */
ret = wait_for_completion_killable_timeout(&data->ranging,
HZ/10);
if (ret < 0)
goto error_unlock;
else if (ret == 0) {
ret = -ETIMEDOUT;
goto error_unlock;
}
} else {
/* use simple sleep if announce irq is not connected */
msleep(15);
}
ret = i2c_master_recv(client, (char *)&buf, sizeof(buf));
if (ret < 0) {
dev_err(&client->dev, "i2c_master_recv: ret=%d\n", ret);
goto error_unlock;
}
distance = __be16_to_cpu(buf);
/* check for not returning misleading error codes */
if (distance < 0) {
dev_err(&client->dev, "distance=%d\n", distance);
ret = -EINVAL;
goto error_unlock;
}
mutex_unlock(&data->lock);
return distance;
error_unlock:
mutex_unlock(&data->lock);
return ret;
}
static irqreturn_t mb1232_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct mb1232_data *data = iio_priv(indio_dev);
data->scan.distance = mb1232_read_distance(data);
if (data->scan.distance < 0)
goto err;
iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
pf->timestamp);
err:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static int mb1232_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *channel, int *val,
int *val2, long mask)
{
struct mb1232_data *data = iio_priv(indio_dev);
int ret;
if (channel->type != IIO_DISTANCE)
return -EINVAL;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = mb1232_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 mb1232_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 mb1232_info = {
.read_raw = mb1232_read_raw,
};
static int mb1232_probe(struct i2c_client *client)
{
const struct i2c_device_id *id = i2c_client_get_device_id(client);
struct iio_dev *indio_dev;
struct mb1232_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 = &mb1232_info;
indio_dev->name = id->name;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = mb1232_channels;
indio_dev->num_channels = ARRAY_SIZE(mb1232_channels);
mutex_init(&data->lock);
init_completion(&data->ranging);
data->irqnr = fwnode_irq_get(dev_fwnode(&client->dev), 0);
if (data->irqnr > 0) {
ret = devm_request_irq(dev, data->irqnr, mb1232_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, mb1232_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_mb1232_match[] = {
{ .compatible = "maxbotix,mb1202", },
{ .compatible = "maxbotix,mb1212", },
{ .compatible = "maxbotix,mb1222", },
{ .compatible = "maxbotix,mb1232", },
{ .compatible = "maxbotix,mb1242", },
{ .compatible = "maxbotix,mb7040", },
{ .compatible = "maxbotix,mb7137", },
{},
};
MODULE_DEVICE_TABLE(of, of_mb1232_match);
static const struct i2c_device_id mb1232_id[] = {
{ "maxbotix-mb1202", },
{ "maxbotix-mb1212", },
{ "maxbotix-mb1222", },
{ "maxbotix-mb1232", },
{ "maxbotix-mb1242", },
{ "maxbotix-mb7040", },
{ "maxbotix-mb7137", },
{ }
};
MODULE_DEVICE_TABLE(i2c, mb1232_id);
static struct i2c_driver mb1232_driver = {
.driver = {
.name = "maxbotix-mb1232",
.of_match_table = of_mb1232_match,
},
.probe = mb1232_probe,
.id_table = mb1232_id,
};
module_i2c_driver(mb1232_driver);
MODULE_AUTHOR("Andreas Klinger <[email protected]>");
MODULE_DESCRIPTION("Maxbotix I2CXL-MaxSonar i2c ultrasonic ranger driver");
MODULE_LICENSE("GPL");
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