| // 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->dev.parent = dev; |
| 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"); |