On 12/08/15 07:01, Matt Ranostay wrote:
> Add support for the PulsedLight LIDAR rangefinder sensor which allows
> high speed (over 300Hz) distance measurements using Barker Coding within
> 40 meter range.
>
> Support only tested on the "blue label" rev 2, but may work using low
> sample frequencies on the original version.
>
> Signed-off-by: Matt Ranostay <mranostay@xxxxxxxxx>
You missed a few cases of the name lidar being used for device
matching.
Also, just noticed you are holding a local lock only when checking if
bufferred capture is enabled. You need to hold the indio_dev->mlock to
avoid racing with a buffer enable.
Mostly there now though.
Jonathan
> ---
> drivers/iio/proximity/Kconfig | 12 +
> drivers/iio/proximity/Makefile | 1 +
> drivers/iio/proximity/pulsedlight-lidar-lite-v2.c | 292 ++++++++++++++++++++++
> 3 files changed, 305 insertions(+)
> create mode 100644 drivers/iio/proximity/pulsedlight-lidar-lite-v2.c
>
> diff --git a/drivers/iio/proximity/Kconfig b/drivers/iio/proximity/Kconfig
> index 41a8d8f..e64fc5b 100644
> --- a/drivers/iio/proximity/Kconfig
> +++ b/drivers/iio/proximity/Kconfig
> @@ -20,6 +20,18 @@ endmenu
>
> menu "Proximity sensors"
>
> +config LIDAR
The config symbol needs more detail as well as it's not a unique
part number.
> + tristate "PulsedLight LIDAR sensor"
> + select IIO_BUFFER
> + select IIO_TRIGGERED_BUFFER
> + depends on I2C
> + help
> + Say Y to build a driver for PulsedLight LIDAR range finding
> + sensor.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called lidar.
Not any more it won't.
> +
> config SX9500
> tristate "SX9500 Semtech proximity sensor"
> select IIO_BUFFER
> diff --git a/drivers/iio/proximity/Makefile b/drivers/iio/proximity/Makefile
> index 9818dc5..081ae33 100644
> --- a/drivers/iio/proximity/Makefile
> +++ b/drivers/iio/proximity/Makefile
> @@ -4,4 +4,5 @@
>
> # When adding new entries keep the list in alphabetical order
> obj-$(CONFIG_AS3935) += as3935.o
> +obj-$(CONFIG_LIDAR) += pulsedlight-lidar-lite-v2.o
> obj-$(CONFIG_SX9500) += sx9500.o
> diff --git a/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c b/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c
> new file mode 100644
> index 0000000..ff0681b
> --- /dev/null
> +++ b/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c
> @@ -0,0 +1,292 @@
> +/*
> + * pulsedlight-lidar-lite-v2.c - Support for PulsedLight LIDAR sensor
> + *
> + * Copyright (C) 2015 Matt Ranostay <mranostay@xxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * TODO: runtime pm, interrupt mode, and signal strength reporting
> + *
No blank line here.
> + */
> +
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/i2c.h>
> +#include <linux/delay.h>
> +#include <linux/mutex.h>
> +#include <linux/module.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/trigger.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include <linux/iio/trigger_consumer.h>
> +
> +#define LIDAR_REG_CONTROL 0x00
> +#define LIDAR_REG_CONTROL_ACQUIRE BIT(2)
> +
> +#define LIDAR_REG_STATUS 0x01
> +#define LIDAR_REG_STATUS_INVALID BIT(3)
> +#define LIDAR_REG_STATUS_READY BIT(0)
> +
> +#define LIDAR_REG_DATA_HBYTE 0x0f
> +#define LIDAR_REG_DATA_LBYTE 0x10
> +
> +#define LIDAR_DRV_NAME "lidar"
> +
> +struct lidar_data {
> + struct mutex lock;
> + struct iio_dev *indio_dev;
> + struct i2c_client *client;
> +
> + u16 buffer[8]; /* 2 byte distance + 8 byte timestamp */
> +};
> +
> +static const struct iio_chan_spec lidar_channels[] = {
> + {
> + .type = IIO_DISTANCE,
> + .info_mask_separate =
> + BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
> + .scan_index = 0,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 16,
> + .storagebits = 16,
> + },
> + },
> + IIO_CHAN_SOFT_TIMESTAMP(1),
> +};
> +
> +static int lidar_read_byte(struct lidar_data *data, int reg)
> +{
> + struct i2c_client *client = data->client;
> + int ret;
> +
> + /*
> + * Device needs a STOP condition between address write, and data read
> + * so in turn i2c_smbus_read_byte_data cannot be used
> + */
> +
> + ret = i2c_smbus_write_byte(client, reg);
> + if (ret < 0) {
> + dev_err(&client->dev, "cannot write addr value");
> + return ret;
> + }
> +
> + ret = i2c_smbus_read_byte(client);
> + if (ret < 0)
> + dev_err(&client->dev, "cannot read data value");
> +
> + return ret;
> +}
> +
> +static inline int lidar_write_control(struct lidar_data *data, int val)
> +{
> + return i2c_smbus_write_byte_data(data->client, LIDAR_REG_CONTROL, val);
> +}
> +
> +static int lidar_read_measurement(struct lidar_data *data, u16 *reg)
> +{
> + int ret;
> + int val;
> +
> + ret = lidar_read_byte(data, LIDAR_REG_DATA_HBYTE);
> + if (ret < 0)
> + return ret;
> + val = ret << 8;
> +
> + ret = lidar_read_byte(data, LIDAR_REG_DATA_LBYTE);
> + if (ret < 0)
> + return ret;
> +
> + val |= ret;
> + *reg = val;
> +
> + return 0;
> +}
> +
> +static int lidar_get_measurement(struct lidar_data *data, u16 *reg)
> +{
> + struct i2c_client *client = data->client;
> + int tries = 10;
> + int ret;
> +
> + /* start sample */
> + ret = lidar_write_control(data, LIDAR_REG_CONTROL_ACQUIRE);
> + if (ret < 0) {
> + dev_err(&client->dev, "cannot send start measurement command");
> + return ret;
> + }
> +
> + while (tries--) {
> + usleep_range(1000, 2000);
> +
> + ret = lidar_read_byte(data, LIDAR_REG_STATUS);
> + if (ret < 0)
> + break;
> +
> + /* return 0 since laser is likely pointed out of range */
> + if (ret & LIDAR_REG_STATUS_INVALID) {
> + *reg = 0;
> + ret = 0;
> + break;
> + }
> +
> + /* sample ready to read */
> + if (!(ret & LIDAR_REG_STATUS_READY)) {
> + ret = lidar_read_measurement(data, reg);
> + break;
> + }
> + ret = -EIO;
> + }
> +
> + return ret;
> +}
> +
> +static int lidar_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> + struct lidar_data *data = iio_priv(indio_dev);
> + int ret = -EINVAL;
> +
> + mutex_lock(&data->lock);
> +
This particular check needs to hold the indio_dev->mlock as that
is the one that protects core state changes (enabling and disabling the
buffer). You want to hang on to that lock until the read is done.
> + if (iio_buffer_enabled(indio_dev) && mask == IIO_CHAN_INFO_RAW) {
> + ret = -EBUSY;
> + goto error_busy;
> + }
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW: {
> + u16 reg;
> +
> + ret = lidar_get_measurement(data, ®);
> + if (!ret) {
> + *val = reg;
> + ret = IIO_VAL_INT;
> + }
> + break;
> + }
> + case IIO_CHAN_INFO_SCALE:
> + *val = 0;
> + *val2 = 10000;
> + ret = IIO_VAL_INT_PLUS_MICRO;
> + break;
> + }
> +
> +error_busy:
> + mutex_unlock(&data->lock);
> +
> + return ret;
> +}
> +
> +static irqreturn_t lidar_trigger_handler(int irq, void *private)
> +{
> + struct iio_poll_func *pf = private;
> + struct iio_dev *indio_dev = pf->indio_dev;
> + struct lidar_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + ret = lidar_get_measurement(data, data->buffer);
> + if (!ret) {
> + iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
> + iio_get_time_ns());
> + } else {
> + dev_err(&data->client->dev, "cannot read LIDAR measurement");
> + }
> +
> + iio_trigger_notify_done(indio_dev->trig);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static const struct iio_info lidar_info = {
> + .driver_module = THIS_MODULE,
> + .read_raw = lidar_read_raw,
> +};
> +
> +static int lidar_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct lidar_data *data;
> + struct iio_dev *indio_dev;
> + int ret;
> +
> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + indio_dev->info = &lidar_info;
> + indio_dev->name = LIDAR_DRV_NAME;
> + indio_dev->channels = lidar_channels;
> + indio_dev->num_channels = ARRAY_SIZE(lidar_channels);
> + indio_dev->modes = INDIO_DIRECT_MODE;
> +
> + data = iio_priv(indio_dev);
> + i2c_set_clientdata(client, indio_dev);
> +
> + data->client = client;
> + data->indio_dev = indio_dev;
> + mutex_init(&data->lock);
> +
> + ret = iio_triggered_buffer_setup(indio_dev, NULL,
> + lidar_trigger_handler, NULL);
> + if (ret)
> + return ret;
> +
> + ret = iio_device_register(indio_dev);
> + if (ret)
> + goto error_unreg_buffer;
> +
> + return 0;
> +
> +error_unreg_buffer:
> + iio_triggered_buffer_cleanup(indio_dev);
> +
> + return ret;
> +}
> +
> +static int lidar_remove(struct i2c_client *client)
> +{
> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +
> + iio_device_unregister(indio_dev);
> + iio_triggered_buffer_cleanup(indio_dev);
> +
> + return 0;
> +}
> +
> +static const struct i2c_device_id lidar_id[] = {
> + {"lidar", 0},
This one wants a longer name as well. It's afterall used for
matching in some circumstances.
> + { },
> +};
> +MODULE_DEVICE_TABLE(i2c, lidar_id);
> +
> +static const struct of_device_id lidar_dt_ids[] = {
> + { .compatible = "pulsedlight,lidar-lite-v2" },
> + { }
> +};
> +
> +static struct i2c_driver lidar_driver = {
> + .driver = {
> + .name = LIDAR_DRV_NAME,
> + .of_match_table = of_match_ptr(lidar_dt_ids),
> + },
> + .probe = lidar_probe,
> + .remove = lidar_remove,
> + .id_table = lidar_id,
> +};
> +module_i2c_driver(lidar_driver);
> +
> +MODULE_AUTHOR("Matt Ranostay <mranostay@xxxxxxxxx>");
> +MODULE_DESCRIPTION("PulsedLight LIDAR sensor");
> +MODULE_LICENSE("GPL");
>
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