| /* |
| * 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: 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/pm_runtime.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_REG_PWR_CONTROL 0x65 |
| |
| #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 inline int lidar_write_power(struct lidar_data *data, int val) |
| { |
| return i2c_smbus_write_byte_data(data->client, |
| LIDAR_REG_PWR_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; |
| |
| pm_runtime_get_sync(&client->dev); |
| |
| /* 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; |
| } |
| pm_runtime_mark_last_busy(&client->dev); |
| pm_runtime_put_autosuspend(&client->dev); |
| |
| 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; |
| |
| pm_runtime_set_autosuspend_delay(&client->dev, 1000); |
| pm_runtime_use_autosuspend(&client->dev); |
| |
| ret = pm_runtime_set_active(&client->dev); |
| if (ret) |
| goto error_unreg_buffer; |
| pm_runtime_enable(&client->dev); |
| |
| pm_runtime_mark_last_busy(&client->dev); |
| pm_runtime_idle(&client->dev); |
| |
| 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); |
| |
| pm_runtime_disable(&client->dev); |
| pm_runtime_set_suspended(&client->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" }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(of, lidar_dt_ids); |
| |
| #ifdef CONFIG_PM |
| static int lidar_pm_runtime_suspend(struct device *dev) |
| { |
| struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); |
| struct lidar_data *data = iio_priv(indio_dev); |
| |
| return lidar_write_power(data, 0x0f); |
| } |
| |
| static int lidar_pm_runtime_resume(struct device *dev) |
| { |
| struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); |
| struct lidar_data *data = iio_priv(indio_dev); |
| int ret = lidar_write_power(data, 0); |
| |
| /* regulator and FPGA needs settling time */ |
| usleep_range(15000, 20000); |
| |
| return ret; |
| } |
| #endif |
| |
| static const struct dev_pm_ops lidar_pm_ops = { |
| SET_RUNTIME_PM_OPS(lidar_pm_runtime_suspend, |
| lidar_pm_runtime_resume, NULL) |
| }; |
| |
| static struct i2c_driver lidar_driver = { |
| .driver = { |
| .name = LIDAR_DRV_NAME, |
| .of_match_table = of_match_ptr(lidar_dt_ids), |
| .pm = &lidar_pm_ops, |
| }, |
| .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"); |