| // SPDX-License-Identifier: GPL-2.0+ | 
 | /* | 
 |  * pulsedlight-lidar-lite-v2.c - Support for PulsedLight LIDAR sensor | 
 |  * | 
 |  * Copyright (C) 2015, 2017-2018 | 
 |  * Author: Matt Ranostay <matt.ranostay@konsulko.com> | 
 |  * | 
 |  * 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_DATA_WORD_READ	BIT(7) | 
 |  | 
 | #define LIDAR_REG_PWR_CONTROL	0x65 | 
 |  | 
 | #define LIDAR_DRV_NAME "lidar" | 
 |  | 
 | struct lidar_data { | 
 | 	struct iio_dev *indio_dev; | 
 | 	struct i2c_client *client; | 
 |  | 
 | 	int (*xfer)(struct lidar_data *data, u8 reg, u8 *val, int len); | 
 | 	int i2c_enabled; | 
 |  | 
 | 	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_i2c_xfer(struct lidar_data *data, u8 reg, u8 *val, int len) | 
 | { | 
 | 	struct i2c_client *client = data->client; | 
 | 	struct i2c_msg msg[2]; | 
 | 	int ret; | 
 |  | 
 | 	msg[0].addr = client->addr; | 
 | 	msg[0].flags = client->flags | I2C_M_STOP; | 
 | 	msg[0].len = 1; | 
 | 	msg[0].buf  = (char *) ® | 
 |  | 
 | 	msg[1].addr = client->addr; | 
 | 	msg[1].flags = client->flags | I2C_M_RD; | 
 | 	msg[1].len = len; | 
 | 	msg[1].buf = (char *) val; | 
 |  | 
 | 	ret = i2c_transfer(client->adapter, msg, 2); | 
 |  | 
 | 	return (ret == 2) ? 0 : -EIO; | 
 | } | 
 |  | 
 | static int lidar_smbus_xfer(struct lidar_data *data, u8 reg, u8 *val, int len) | 
 | { | 
 | 	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 | 
 | 	 */ | 
 |  | 
 | 	while (len--) { | 
 | 		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; | 
 | 		} | 
 |  | 
 | 		*(val++) = ret; | 
 | 	} | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int lidar_read_byte(struct lidar_data *data, u8 reg) | 
 | { | 
 | 	int ret; | 
 | 	u8 val; | 
 |  | 
 | 	ret = data->xfer(data, reg, &val, 1); | 
 | 	if (ret < 0) | 
 | 		return ret; | 
 |  | 
 | 	return val; | 
 | } | 
 |  | 
 | 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 = data->xfer(data, LIDAR_REG_DATA_HBYTE | | 
 | 			(data->i2c_enabled ? LIDAR_REG_DATA_WORD_READ : 0), | 
 | 			(u8 *) reg, 2); | 
 |  | 
 | 	if (!ret) | 
 | 		*reg = be16_to_cpu(*reg); | 
 |  | 
 | 	return ret; | 
 | } | 
 |  | 
 | 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 -EINVAL since laser is likely pointed out of range */ | 
 | 		if (ret & LIDAR_REG_STATUS_INVALID) { | 
 | 			*reg = 0; | 
 | 			ret = -EINVAL; | 
 | 			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; | 
 |  | 
 | 	switch (mask) { | 
 | 	case IIO_CHAN_INFO_RAW: { | 
 | 		u16 reg; | 
 |  | 
 | 		if (iio_device_claim_direct_mode(indio_dev)) | 
 | 			return -EBUSY; | 
 |  | 
 | 		ret = lidar_get_measurement(data, ®); | 
 | 		if (!ret) { | 
 | 			*val = reg; | 
 | 			ret = IIO_VAL_INT; | 
 | 		} | 
 | 		iio_device_release_direct_mode(indio_dev); | 
 | 		break; | 
 | 	} | 
 | 	case IIO_CHAN_INFO_SCALE: | 
 | 		*val = 0; | 
 | 		*val2 = 10000; | 
 | 		ret = IIO_VAL_INT_PLUS_MICRO; | 
 | 		break; | 
 | 	} | 
 |  | 
 | 	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(indio_dev)); | 
 | 	} else if (ret != -EINVAL) { | 
 | 		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 = { | 
 | 	.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; | 
 | 	data = iio_priv(indio_dev); | 
 |  | 
 | 	if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { | 
 | 		data->xfer = lidar_i2c_xfer; | 
 | 		data->i2c_enabled = 1; | 
 | 	} else if (i2c_check_functionality(client->adapter, | 
 | 				I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE)) | 
 | 		data->xfer = lidar_smbus_xfer; | 
 | 	else | 
 | 		return -EOPNOTSUPP; | 
 |  | 
 | 	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->dev.parent = &client->dev; | 
 | 	indio_dev->modes = INDIO_DIRECT_MODE; | 
 |  | 
 | 	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_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}, | 
 | 	{"lidar-lite-v3", 0}, | 
 | 	{ }, | 
 | }; | 
 | MODULE_DEVICE_TABLE(i2c, lidar_id); | 
 |  | 
 | static const struct of_device_id lidar_dt_ids[] = { | 
 | 	{ .compatible = "pulsedlight,lidar-lite-v2" }, | 
 | 	{ .compatible = "grmn,lidar-lite-v3" }, | 
 | 	{ } | 
 | }; | 
 | 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 <matt.ranostay@konsulko.com>"); | 
 | MODULE_DESCRIPTION("PulsedLight LIDAR sensor"); | 
 | MODULE_LICENSE("GPL"); |