diff options
Diffstat (limited to 'drivers/iio/proximity/mb1232.c')
| -rw-r--r-- | drivers/iio/proximity/mb1232.c | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/drivers/iio/proximity/mb1232.c b/drivers/iio/proximity/mb1232.c new file mode 100644 index 000000000..ad4b1fb26 --- /dev/null +++ b/drivers/iio/proximity/mb1232.c @@ -0,0 +1,272 @@ +// 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 <ak@it-klinger.de> + * + * 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/of_irq.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 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) +{ + 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 = irq_of_parse_and_map(dev->of_node, 0); + if (data->irqnr <= 0) { + /* usage of interrupt is optional */ + data->irqnr = -1; + } else { + 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 <ak@it-klinger.de>"); +MODULE_DESCRIPTION("Maxbotix I2CXL-MaxSonar i2c ultrasonic ranger driver"); +MODULE_LICENSE("GPL"); |