--- /dev/null
+/*
+ * pulsedlight-lidar-lite-v2.c - Support for PulsedLight LIDAR sensor
+ *
+ * Copyright (C) 2015 Matt Ranostay <mranostay@gmail.com>
+ *
+ * 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
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/delay.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 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(&indio_dev->mlock);
+
+ 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(&indio_dev->mlock);
+
+ 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;
+
+ 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-lite-v2", 0},
+ { },
+};
+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@gmail.com>");
+MODULE_DESCRIPTION("PulsedLight LIDAR sensor");
+MODULE_LICENSE("GPL");
projects / platform / kernel / linux-starfive.git / commitdiff