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559 lines
13 KiB
559 lines
13 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* srf08.c - Support for Devantech SRFxx ultrasonic ranger |
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* with i2c interface |
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* actually supported are srf02, srf08, srf10 |
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* |
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* Copyright (c) 2016, 2017 Andreas Klinger <[email protected]> |
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* |
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* For details about the device see: |
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* https://www.robot-electronics.co.uk/htm/srf08tech.html |
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* https://www.robot-electronics.co.uk/htm/srf10tech.htm |
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* https://www.robot-electronics.co.uk/htm/srf02tech.htm |
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*/ |
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#include <linux/err.h> |
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#include <linux/i2c.h> |
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#include <linux/delay.h> |
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#include <linux/module.h> |
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#include <linux/bitops.h> |
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#include <linux/iio/iio.h> |
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#include <linux/iio/sysfs.h> |
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#include <linux/iio/buffer.h> |
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#include <linux/iio/trigger_consumer.h> |
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#include <linux/iio/triggered_buffer.h> |
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|
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/* registers of SRF08 device */ |
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#define SRF08_WRITE_COMMAND 0x00 /* Command Register */ |
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#define SRF08_WRITE_MAX_GAIN 0x01 /* Max Gain Register: 0 .. 31 */ |
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#define SRF08_WRITE_RANGE 0x02 /* Range Register: 0 .. 255 */ |
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#define SRF08_READ_SW_REVISION 0x00 /* Software Revision */ |
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#define SRF08_READ_LIGHT 0x01 /* Light Sensor during last echo */ |
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#define SRF08_READ_ECHO_1_HIGH 0x02 /* Range of first echo received */ |
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#define SRF08_READ_ECHO_1_LOW 0x03 /* Range of first echo received */ |
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|
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#define SRF08_CMD_RANGING_CM 0x51 /* Ranging Mode - Result in cm */ |
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|
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enum srf08_sensor_type { |
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SRF02, |
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SRF08, |
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SRF10, |
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SRF_MAX_TYPE |
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}; |
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struct srf08_chip_info { |
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const int *sensitivity_avail; |
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int num_sensitivity_avail; |
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int sensitivity_default; |
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|
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/* default value of Range in mm */ |
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int range_default; |
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}; |
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|
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struct srf08_data { |
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struct i2c_client *client; |
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|
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/* |
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* Gain in the datasheet is called sensitivity here to distinct it |
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* from the gain used with amplifiers of adc's |
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*/ |
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int sensitivity; |
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|
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/* max. Range in mm */ |
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int range_mm; |
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struct mutex lock; |
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|
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/* |
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* triggered buffer |
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* 1x16-bit channel + 3x16 padding + 4x16 timestamp |
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*/ |
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s16 buffer[8]; |
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|
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/* Sensor-Type */ |
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enum srf08_sensor_type sensor_type; |
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|
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/* Chip-specific information */ |
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const struct srf08_chip_info *chip_info; |
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}; |
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|
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/* |
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* in the documentation one can read about the "Gain" of the device |
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* which is used here for amplifying the signal and filtering out unwanted |
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* ones. |
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* But with ADC's this term is already used differently and that's why it |
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* is called "Sensitivity" here. |
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*/ |
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static const struct srf08_chip_info srf02_chip_info = { |
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.sensitivity_avail = NULL, |
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.num_sensitivity_avail = 0, |
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.sensitivity_default = 0, |
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.range_default = 0, |
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}; |
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static const int srf08_sensitivity_avail[] = { |
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94, 97, 100, 103, 107, 110, 114, 118, |
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123, 128, 133, 139, 145, 152, 159, 168, |
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177, 187, 199, 212, 227, 245, 265, 288, |
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317, 352, 395, 450, 524, 626, 777, 1025 |
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}; |
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static const struct srf08_chip_info srf08_chip_info = { |
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.sensitivity_avail = srf08_sensitivity_avail, |
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.num_sensitivity_avail = ARRAY_SIZE(srf08_sensitivity_avail), |
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.sensitivity_default = 1025, |
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.range_default = 6020, |
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}; |
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static const int srf10_sensitivity_avail[] = { |
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40, 40, 50, 60, 70, 80, 100, 120, |
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140, 200, 250, 300, 350, 400, 500, 600, |
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700, |
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}; |
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static const struct srf08_chip_info srf10_chip_info = { |
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.sensitivity_avail = srf10_sensitivity_avail, |
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.num_sensitivity_avail = ARRAY_SIZE(srf10_sensitivity_avail), |
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.sensitivity_default = 700, |
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.range_default = 6020, |
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}; |
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static int srf08_read_ranging(struct srf08_data *data) |
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{ |
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struct i2c_client *client = data->client; |
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int ret, i; |
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int waittime; |
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mutex_lock(&data->lock); |
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ret = i2c_smbus_write_byte_data(data->client, |
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SRF08_WRITE_COMMAND, SRF08_CMD_RANGING_CM); |
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if (ret < 0) { |
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dev_err(&client->dev, "write command - err: %d\n", ret); |
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mutex_unlock(&data->lock); |
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return ret; |
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} |
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|
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/* |
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* we read here until a correct version number shows up as |
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* suggested by the documentation |
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* |
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* with an ultrasonic speed of 343 m/s and a roundtrip of it |
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* sleep the expected duration and try to read from the device |
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* if nothing useful is read try it in a shorter grid |
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* |
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* polling for not more than 20 ms should be enough |
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*/ |
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waittime = 1 + data->range_mm / 172; |
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msleep(waittime); |
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for (i = 0; i < 4; i++) { |
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ret = i2c_smbus_read_byte_data(data->client, |
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SRF08_READ_SW_REVISION); |
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/* check if a valid version number is read */ |
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if (ret < 255 && ret > 0) |
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break; |
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msleep(5); |
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} |
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if (ret >= 255 || ret <= 0) { |
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dev_err(&client->dev, "device not ready\n"); |
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mutex_unlock(&data->lock); |
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return -EIO; |
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} |
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ret = i2c_smbus_read_word_swapped(data->client, |
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SRF08_READ_ECHO_1_HIGH); |
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if (ret < 0) { |
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dev_err(&client->dev, "cannot read distance: ret=%d\n", ret); |
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mutex_unlock(&data->lock); |
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return ret; |
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} |
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mutex_unlock(&data->lock); |
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return ret; |
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} |
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static irqreturn_t srf08_trigger_handler(int irq, void *p) |
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{ |
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struct iio_poll_func *pf = p; |
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struct iio_dev *indio_dev = pf->indio_dev; |
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struct srf08_data *data = iio_priv(indio_dev); |
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s16 sensor_data; |
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sensor_data = srf08_read_ranging(data); |
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if (sensor_data < 0) |
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goto err; |
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mutex_lock(&data->lock); |
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data->buffer[0] = sensor_data; |
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iio_push_to_buffers_with_timestamp(indio_dev, |
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data->buffer, pf->timestamp); |
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mutex_unlock(&data->lock); |
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err: |
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iio_trigger_notify_done(indio_dev->trig); |
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return IRQ_HANDLED; |
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} |
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static int srf08_read_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *channel, int *val, |
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int *val2, long mask) |
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{ |
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struct srf08_data *data = iio_priv(indio_dev); |
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int ret; |
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if (channel->type != IIO_DISTANCE) |
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return -EINVAL; |
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switch (mask) { |
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case IIO_CHAN_INFO_RAW: |
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ret = srf08_read_ranging(data); |
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if (ret < 0) |
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return ret; |
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*val = ret; |
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return IIO_VAL_INT; |
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case IIO_CHAN_INFO_SCALE: |
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/* 1 LSB is 1 cm */ |
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*val = 0; |
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*val2 = 10000; |
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return IIO_VAL_INT_PLUS_MICRO; |
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default: |
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return -EINVAL; |
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} |
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} |
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static ssize_t srf08_show_range_mm_available(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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return sprintf(buf, "[0.043 0.043 11.008]\n"); |
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} |
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static IIO_DEVICE_ATTR(sensor_max_range_available, S_IRUGO, |
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srf08_show_range_mm_available, NULL, 0); |
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static ssize_t srf08_show_range_mm(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
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struct srf08_data *data = iio_priv(indio_dev); |
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return sprintf(buf, "%d.%03d\n", data->range_mm / 1000, |
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data->range_mm % 1000); |
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} |
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/* |
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* set the range of the sensor to an even multiple of 43 mm |
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* which corresponds to 1 LSB in the register |
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* |
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* register value corresponding range |
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* 0x00 43 mm |
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* 0x01 86 mm |
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* 0x02 129 mm |
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* ... |
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* 0xFF 11008 mm |
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*/ |
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static ssize_t srf08_write_range_mm(struct srf08_data *data, unsigned int val) |
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{ |
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int ret; |
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struct i2c_client *client = data->client; |
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unsigned int mod; |
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u8 regval; |
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ret = val / 43 - 1; |
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mod = val % 43; |
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if (mod || (ret < 0) || (ret > 255)) |
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return -EINVAL; |
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regval = ret; |
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mutex_lock(&data->lock); |
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ret = i2c_smbus_write_byte_data(client, SRF08_WRITE_RANGE, regval); |
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if (ret < 0) { |
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dev_err(&client->dev, "write_range - err: %d\n", ret); |
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mutex_unlock(&data->lock); |
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return ret; |
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} |
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data->range_mm = val; |
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mutex_unlock(&data->lock); |
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return 0; |
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} |
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static ssize_t srf08_store_range_mm(struct device *dev, |
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struct device_attribute *attr, |
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const char *buf, size_t len) |
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{ |
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struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
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struct srf08_data *data = iio_priv(indio_dev); |
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int ret; |
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int integer, fract; |
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ret = iio_str_to_fixpoint(buf, 100, &integer, &fract); |
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if (ret) |
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return ret; |
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ret = srf08_write_range_mm(data, integer * 1000 + fract); |
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if (ret < 0) |
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return ret; |
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return len; |
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} |
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static IIO_DEVICE_ATTR(sensor_max_range, S_IRUGO | S_IWUSR, |
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srf08_show_range_mm, srf08_store_range_mm, 0); |
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static ssize_t srf08_show_sensitivity_available(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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int i, len = 0; |
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struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
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struct srf08_data *data = iio_priv(indio_dev); |
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for (i = 0; i < data->chip_info->num_sensitivity_avail; i++) |
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if (data->chip_info->sensitivity_avail[i]) |
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len += sprintf(buf + len, "%d ", |
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data->chip_info->sensitivity_avail[i]); |
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len += sprintf(buf + len, "\n"); |
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return len; |
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} |
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static IIO_DEVICE_ATTR(sensor_sensitivity_available, S_IRUGO, |
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srf08_show_sensitivity_available, NULL, 0); |
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static ssize_t srf08_show_sensitivity(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
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struct srf08_data *data = iio_priv(indio_dev); |
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int len; |
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len = sprintf(buf, "%d\n", data->sensitivity); |
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return len; |
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} |
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static ssize_t srf08_write_sensitivity(struct srf08_data *data, |
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unsigned int val) |
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{ |
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struct i2c_client *client = data->client; |
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int ret, i; |
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u8 regval; |
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if (!val) |
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return -EINVAL; |
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for (i = 0; i < data->chip_info->num_sensitivity_avail; i++) |
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if (val && (val == data->chip_info->sensitivity_avail[i])) { |
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regval = i; |
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break; |
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} |
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if (i >= data->chip_info->num_sensitivity_avail) |
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return -EINVAL; |
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mutex_lock(&data->lock); |
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ret = i2c_smbus_write_byte_data(client, SRF08_WRITE_MAX_GAIN, regval); |
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if (ret < 0) { |
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dev_err(&client->dev, "write_sensitivity - err: %d\n", ret); |
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mutex_unlock(&data->lock); |
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return ret; |
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} |
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data->sensitivity = val; |
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mutex_unlock(&data->lock); |
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return 0; |
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} |
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static ssize_t srf08_store_sensitivity(struct device *dev, |
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struct device_attribute *attr, |
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const char *buf, size_t len) |
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{ |
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struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
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struct srf08_data *data = iio_priv(indio_dev); |
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int ret; |
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unsigned int val; |
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ret = kstrtouint(buf, 10, &val); |
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if (ret) |
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return ret; |
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ret = srf08_write_sensitivity(data, val); |
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if (ret < 0) |
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return ret; |
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return len; |
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} |
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static IIO_DEVICE_ATTR(sensor_sensitivity, S_IRUGO | S_IWUSR, |
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srf08_show_sensitivity, srf08_store_sensitivity, 0); |
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static struct attribute *srf08_attributes[] = { |
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&iio_dev_attr_sensor_max_range.dev_attr.attr, |
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&iio_dev_attr_sensor_max_range_available.dev_attr.attr, |
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&iio_dev_attr_sensor_sensitivity.dev_attr.attr, |
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&iio_dev_attr_sensor_sensitivity_available.dev_attr.attr, |
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NULL, |
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}; |
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static const struct attribute_group srf08_attribute_group = { |
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.attrs = srf08_attributes, |
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}; |
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static const struct iio_chan_spec srf08_channels[] = { |
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{ |
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.type = IIO_DISTANCE, |
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.info_mask_separate = |
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BIT(IIO_CHAN_INFO_RAW) | |
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BIT(IIO_CHAN_INFO_SCALE), |
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.scan_index = 0, |
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.scan_type = { |
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.sign = 's', |
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.realbits = 16, |
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.storagebits = 16, |
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.endianness = IIO_CPU, |
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}, |
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}, |
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IIO_CHAN_SOFT_TIMESTAMP(1), |
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}; |
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static const struct iio_info srf08_info = { |
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.read_raw = srf08_read_raw, |
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.attrs = &srf08_attribute_group, |
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}; |
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/* |
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* srf02 don't have an adjustable range or sensitivity, |
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* so we don't need attributes at all |
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*/ |
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static const struct iio_info srf02_info = { |
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.read_raw = srf08_read_raw, |
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}; |
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static int srf08_probe(struct i2c_client *client, |
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const struct i2c_device_id *id) |
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{ |
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struct iio_dev *indio_dev; |
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struct srf08_data *data; |
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int ret; |
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if (!i2c_check_functionality(client->adapter, |
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I2C_FUNC_SMBUS_READ_BYTE_DATA | |
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I2C_FUNC_SMBUS_WRITE_BYTE_DATA | |
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I2C_FUNC_SMBUS_READ_WORD_DATA)) |
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return -ENODEV; |
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indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); |
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if (!indio_dev) |
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return -ENOMEM; |
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data = iio_priv(indio_dev); |
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i2c_set_clientdata(client, indio_dev); |
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data->client = client; |
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data->sensor_type = (enum srf08_sensor_type)id->driver_data; |
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switch (data->sensor_type) { |
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case SRF02: |
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data->chip_info = &srf02_chip_info; |
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indio_dev->info = &srf02_info; |
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break; |
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case SRF08: |
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data->chip_info = &srf08_chip_info; |
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indio_dev->info = &srf08_info; |
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break; |
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case SRF10: |
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data->chip_info = &srf10_chip_info; |
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indio_dev->info = &srf08_info; |
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break; |
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default: |
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return -EINVAL; |
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} |
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indio_dev->name = id->name; |
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indio_dev->modes = INDIO_DIRECT_MODE; |
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indio_dev->channels = srf08_channels; |
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indio_dev->num_channels = ARRAY_SIZE(srf08_channels); |
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mutex_init(&data->lock); |
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ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, |
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iio_pollfunc_store_time, srf08_trigger_handler, NULL); |
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if (ret < 0) { |
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dev_err(&client->dev, "setup of iio triggered buffer failed\n"); |
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return ret; |
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} |
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if (data->chip_info->range_default) { |
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/* |
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* set default range of device in mm here |
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* these register values cannot be read from the hardware |
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* therefore set driver specific default values |
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* |
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* srf02 don't have a default value so it'll be omitted |
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*/ |
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ret = srf08_write_range_mm(data, |
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data->chip_info->range_default); |
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if (ret < 0) |
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return ret; |
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} |
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if (data->chip_info->sensitivity_default) { |
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/* |
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* set default sensitivity of device here |
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* these register values cannot be read from the hardware |
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* therefore set driver specific default values |
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* |
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* srf02 don't have a default value so it'll be omitted |
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*/ |
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ret = srf08_write_sensitivity(data, |
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data->chip_info->sensitivity_default); |
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if (ret < 0) |
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return ret; |
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} |
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return devm_iio_device_register(&client->dev, indio_dev); |
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} |
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static const struct of_device_id of_srf08_match[] = { |
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{ .compatible = "devantech,srf02", (void *)SRF02}, |
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{ .compatible = "devantech,srf08", (void *)SRF08}, |
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{ .compatible = "devantech,srf10", (void *)SRF10}, |
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{}, |
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}; |
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MODULE_DEVICE_TABLE(of, of_srf08_match); |
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|
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static const struct i2c_device_id srf08_id[] = { |
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{ "srf02", SRF02 }, |
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{ "srf08", SRF08 }, |
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{ "srf10", SRF10 }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(i2c, srf08_id); |
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|
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static struct i2c_driver srf08_driver = { |
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.driver = { |
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.name = "srf08", |
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.of_match_table = of_srf08_match, |
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}, |
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.probe = srf08_probe, |
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.id_table = srf08_id, |
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}; |
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module_i2c_driver(srf08_driver); |
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|
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MODULE_AUTHOR("Andreas Klinger <[email protected]>"); |
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MODULE_DESCRIPTION("Devantech SRF02/SRF08/SRF10 i2c ultrasonic ranger driver"); |
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MODULE_LICENSE("GPL");
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