On Sun, 24 Feb 2019, Andreas Klinger wrote: comments below > Add MaxSonar-I2CXL ultrasonic distance sensors of type family mb12x2 > using the i2c interface > > Implemented functionality: > - reading the distance via in_distance_raw > - buffered mode with trigger > - make use of status gpio to announce completion of ranging > > Signed-off-by: Andreas Klinger <ak@xxxxxxxxxxxxx> > --- > drivers/iio/proximity/mb12x2.c | 283 +++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 283 insertions(+) > create mode 100644 drivers/iio/proximity/mb12x2.c > > diff --git a/drivers/iio/proximity/mb12x2.c b/drivers/iio/proximity/mb12x2.c > new file mode 100644 > index 000000000000..0c052fde94b4 > --- /dev/null > +++ b/drivers/iio/proximity/mb12x2.c > @@ -0,0 +1,283 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * mb12x2.c - Support for I2CXL-MaxSonar-EZ series ultrasonic ranger with > + * i2c interface > + * actually supported are mb12x2 types > + * > + * Copyright (c) 2019 Andreas Klinger <ak@xxxxxxxxxxxxx> > + * > + * 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/gpio/consumer.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 MB12X2_RANGE_COMMAND 0x51 /* Command for reading range */ > +#define MB12X2_ADDR_UNLOCK_1 0xAA /* Command 1 for changing address */ > +#define MB12X2_ADDR_UNLOCK_2 0xA5 /* Command 2 for changing address */ > + > +struct mb12x2_data { > + struct i2c_client *client; > + > + struct mutex lock; > + > + /* > + * optionally a gpio can be used to announce when ranging has > + * finished > + */ > + struct completion ranging; > + struct gpio_desc *gpiod_status; > + int irqnr; > + > + /* > + * triggered buffer > + * 1x16-bit channel + 3x16 padding + 4x16 timestamp > + */ > + s16 buffer[8]; > +}; > + > +static irqreturn_t mb12x2_handle_irq(int irq, void *dev_id) > +{ > + struct iio_dev *indio_dev = dev_id; > + struct mb12x2_data *data = iio_priv(indio_dev); > + > + /* double check to make sure data is now available */ > + if (!gpiod_get_value(data->gpiod_status)) > + complete(&data->ranging); > + > + return IRQ_HANDLED; > +} > + > +static int mb12x2_read_distance(struct mb12x2_data *data) > +{ > + struct i2c_client *client = data->client; > + int ret; > + int distance; > + unsigned char buf[2]; use __le16? > + > + mutex_lock(&data->lock); > + > + reinit_completion(&data->ranging); > + > + ret = i2c_smbus_write_byte(client, MB12X2_RANGE_COMMAND); > + if (ret < 0) { > + dev_err(&client->dev, "write command - err: %d\n", ret); > + mutex_unlock(&data->lock); > + return ret; > + } > + > + if (data->gpiod_status) { > + /* it cannot take more than 100 ms */ > + ret = wait_for_completion_killable_timeout(&data->ranging, > + HZ/10); > + if (ret < 0) { > + mutex_unlock(&data->lock); > + return ret; > + } else if (ret == 0) { > + mutex_unlock(&data->lock); > + return -ETIMEDOUT; > + } > + } else { > + /* > + * use simple sleep if gpio announce pin is not connected > + */ > + msleep(15); > + } > + > + > + ret = i2c_master_recv(client, buf, sizeof(buf)); > + if (ret < 0) { > + dev_err(&client->dev, "i2c_master_recv: ret=%d\n", ret); > + mutex_unlock(&data->lock); > + return ret; > + } > + > + distance = buf[0]<<8 | buf[1]; __le16_to_cpu() > + > + mutex_unlock(&data->lock); > + > + return distance; > +} > + > +static irqreturn_t mb12x2_trigger_handler(int irq, void *p) > +{ > + struct iio_poll_func *pf = p; > + struct iio_dev *indio_dev = pf->indio_dev; > + struct mb12x2_data *data = iio_priv(indio_dev); > + s16 sensor_data; > + > + sensor_data = mb12x2_read_distance(data); _read_distance() returns int, not s16 what if the distance is >= 0x8000? > + if (sensor_data < 0) > + goto err; > + > + mutex_lock(&data->lock); > + > + data->buffer[0] = sensor_data; > + iio_push_to_buffers_with_timestamp(indio_dev, > + data->buffer, pf->timestamp); > + > + mutex_unlock(&data->lock); > +err: > + iio_trigger_notify_done(indio_dev->trig); > + return IRQ_HANDLED; > +} > + > +static int mb12x2_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *channel, int *val, > + int *val2, long mask) > +{ > + struct mb12x2_data *data = iio_priv(indio_dev); > + int ret; > + > + if (channel->type != IIO_DISTANCE) > + return -EINVAL; > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + ret = mb12x2_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 mb12x2_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 mb12x2_info = { > + .read_raw = mb12x2_read_raw, > +}; > + > +static int mb12x2_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + struct iio_dev *indio_dev; > + struct mb12x2_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 = &mb12x2_info; > + indio_dev->name = id->name; > + indio_dev->dev.parent = dev; > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->channels = mb12x2_channels; > + indio_dev->num_channels = ARRAY_SIZE(mb12x2_channels); > + > + mutex_init(&data->lock); > + > + init_completion(&data->ranging); > + > + data->gpiod_status = devm_gpiod_get(dev, "status", GPIOD_IN); > + if (IS_ERR(data->gpiod_status)) { I'd rather not do a newline at the start of a block (matter of taste) > + > + if (PTR_ERR(data->gpiod_status) == -ENOENT) { > + > + dev_warn(dev, "no status gpio --> use sleep instead\n"); > + data->gpiod_status = NULL; > + } else { > + > + dev_err(dev, "cannot setup gpio; err=%ld\n", > + PTR_ERR(data->gpiod_status)); > + return PTR_ERR(data->gpiod_status); > + } > + } > + > + if (data->gpiod_status) { > + > + data->irqnr = gpiod_to_irq(data->gpiod_status); > + if (data->irqnr < 0) { > + dev_err(dev, "gpiod_to_irq: %d\n", data->irqnr); > + return data->irqnr; > + } > + > + ret = devm_request_irq(dev, data->irqnr, mb12x2_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, mb12x2_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_mb12x2_match[] = { > + { .compatible = "maxbotix,mb12x2", }, > + {}, > +}; > + > +MODULE_DEVICE_TABLE(of, of_mb12x2_match); > + > +static const struct i2c_device_id mb12x2_id[] = { > + { "maxbotix-mb12x2", }, > + { } > +}; > +MODULE_DEVICE_TABLE(i2c, mb12x2_id); > + > +static struct i2c_driver mb12x2_driver = { > + .driver = { > + .name = "maxbotix-mb12x2", > + .of_match_table = of_mb12x2_match, > + }, > + .probe = mb12x2_probe, > + .id_table = mb12x2_id, > +}; > +module_i2c_driver(mb12x2_driver); > + > +MODULE_AUTHOR("Andreas Klinger <ak@xxxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("Maxbotix I2CXL-MB12X2-EZ i2c ultrasonic ranger driver"); > +MODULE_LICENSE("GPL"); > -- Peter Meerwald-Stadler Mobile: +43 664 24 44 418
