v4.19.13 snapshot.
diff --git a/drivers/iio/proximity/srf08.c b/drivers/iio/proximity/srf08.c
new file mode 100644
index 0000000..f2bf783
--- /dev/null
+++ b/drivers/iio/proximity/srf08.c
@@ -0,0 +1,563 @@
+/*
+ * srf08.c - Support for Devantech SRFxx ultrasonic ranger
+ * with i2c interface
+ * actually supported are srf02, srf08, srf10
+ *
+ * Copyright (c) 2016, 2017 Andreas Klinger <ak@it-klinger.de>
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License. See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ * For details about the device see:
+ * http://www.robot-electronics.co.uk/htm/srf08tech.html
+ * http://www.robot-electronics.co.uk/htm/srf10tech.htm
+ * http://www.robot-electronics.co.uk/htm/srf02tech.htm
+ */
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/bitops.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+/* registers of SRF08 device */
+#define SRF08_WRITE_COMMAND 0x00 /* Command Register */
+#define SRF08_WRITE_MAX_GAIN 0x01 /* Max Gain Register: 0 .. 31 */
+#define SRF08_WRITE_RANGE 0x02 /* Range Register: 0 .. 255 */
+#define SRF08_READ_SW_REVISION 0x00 /* Software Revision */
+#define SRF08_READ_LIGHT 0x01 /* Light Sensor during last echo */
+#define SRF08_READ_ECHO_1_HIGH 0x02 /* Range of first echo received */
+#define SRF08_READ_ECHO_1_LOW 0x03 /* Range of first echo received */
+
+#define SRF08_CMD_RANGING_CM 0x51 /* Ranging Mode - Result in cm */
+
+enum srf08_sensor_type {
+ SRF02,
+ SRF08,
+ SRF10,
+ SRF_MAX_TYPE
+};
+
+struct srf08_chip_info {
+ const int *sensitivity_avail;
+ int num_sensitivity_avail;
+ int sensitivity_default;
+
+ /* default value of Range in mm */
+ int range_default;
+};
+
+struct srf08_data {
+ struct i2c_client *client;
+
+ /*
+ * Gain in the datasheet is called sensitivity here to distinct it
+ * from the gain used with amplifiers of adc's
+ */
+ int sensitivity;
+
+ /* max. Range in mm */
+ int range_mm;
+ struct mutex lock;
+
+ /*
+ * triggered buffer
+ * 1x16-bit channel + 3x16 padding + 4x16 timestamp
+ */
+ s16 buffer[8];
+
+ /* Sensor-Type */
+ enum srf08_sensor_type sensor_type;
+
+ /* Chip-specific information */
+ const struct srf08_chip_info *chip_info;
+};
+
+/*
+ * in the documentation one can read about the "Gain" of the device
+ * which is used here for amplifying the signal and filtering out unwanted
+ * ones.
+ * But with ADC's this term is already used differently and that's why it
+ * is called "Sensitivity" here.
+ */
+static const struct srf08_chip_info srf02_chip_info = {
+ .sensitivity_avail = NULL,
+ .num_sensitivity_avail = 0,
+ .sensitivity_default = 0,
+
+ .range_default = 0,
+};
+
+static const int srf08_sensitivity_avail[] = {
+ 94, 97, 100, 103, 107, 110, 114, 118,
+ 123, 128, 133, 139, 145, 152, 159, 168,
+ 177, 187, 199, 212, 227, 245, 265, 288,
+ 317, 352, 395, 450, 524, 626, 777, 1025
+ };
+
+static const struct srf08_chip_info srf08_chip_info = {
+ .sensitivity_avail = srf08_sensitivity_avail,
+ .num_sensitivity_avail = ARRAY_SIZE(srf08_sensitivity_avail),
+ .sensitivity_default = 1025,
+
+ .range_default = 6020,
+};
+
+static const int srf10_sensitivity_avail[] = {
+ 40, 40, 50, 60, 70, 80, 100, 120,
+ 140, 200, 250, 300, 350, 400, 500, 600,
+ 700,
+ };
+
+static const struct srf08_chip_info srf10_chip_info = {
+ .sensitivity_avail = srf10_sensitivity_avail,
+ .num_sensitivity_avail = ARRAY_SIZE(srf10_sensitivity_avail),
+ .sensitivity_default = 700,
+
+ .range_default = 6020,
+};
+
+static int srf08_read_ranging(struct srf08_data *data)
+{
+ struct i2c_client *client = data->client;
+ int ret, i;
+ int waittime;
+
+ mutex_lock(&data->lock);
+
+ ret = i2c_smbus_write_byte_data(data->client,
+ SRF08_WRITE_COMMAND, SRF08_CMD_RANGING_CM);
+ if (ret < 0) {
+ dev_err(&client->dev, "write command - err: %d\n", ret);
+ mutex_unlock(&data->lock);
+ return ret;
+ }
+
+ /*
+ * we read here until a correct version number shows up as
+ * suggested by the documentation
+ *
+ * with an ultrasonic speed of 343 m/s and a roundtrip of it
+ * sleep the expected duration and try to read from the device
+ * if nothing useful is read try it in a shorter grid
+ *
+ * polling for not more than 20 ms should be enough
+ */
+ waittime = 1 + data->range_mm / 172;
+ msleep(waittime);
+ for (i = 0; i < 4; i++) {
+ ret = i2c_smbus_read_byte_data(data->client,
+ SRF08_READ_SW_REVISION);
+
+ /* check if a valid version number is read */
+ if (ret < 255 && ret > 0)
+ break;
+ msleep(5);
+ }
+
+ if (ret >= 255 || ret <= 0) {
+ dev_err(&client->dev, "device not ready\n");
+ mutex_unlock(&data->lock);
+ return -EIO;
+ }
+
+ ret = i2c_smbus_read_word_swapped(data->client,
+ SRF08_READ_ECHO_1_HIGH);
+ if (ret < 0) {
+ dev_err(&client->dev, "cannot read distance: ret=%d\n", ret);
+ mutex_unlock(&data->lock);
+ return ret;
+ }
+
+ mutex_unlock(&data->lock);
+
+ return ret;
+}
+
+static irqreturn_t srf08_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct srf08_data *data = iio_priv(indio_dev);
+ s16 sensor_data;
+
+ sensor_data = srf08_read_ranging(data);
+ if (sensor_data < 0)
+ goto err;
+
+ mutex_lock(&data->lock);
+
+ data->buffer[0] = sensor_data;
+ iio_push_to_buffers_with_timestamp(indio_dev,
+ data->buffer, pf->timestamp);
+
+ mutex_unlock(&data->lock);
+err:
+ iio_trigger_notify_done(indio_dev->trig);
+ return IRQ_HANDLED;
+}
+
+static int srf08_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *channel, int *val,
+ int *val2, long mask)
+{
+ struct srf08_data *data = iio_priv(indio_dev);
+ int ret;
+
+ if (channel->type != IIO_DISTANCE)
+ return -EINVAL;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = srf08_read_ranging(data);
+ if (ret < 0)
+ return ret;
+ *val = ret;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ /* 1 LSB is 1 cm */
+ *val = 0;
+ *val2 = 10000;
+ return IIO_VAL_INT_PLUS_MICRO;
+ default:
+ return -EINVAL;
+ }
+}
+
+static ssize_t srf08_show_range_mm_available(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "[0.043 0.043 11.008]\n");
+}
+
+static IIO_DEVICE_ATTR(sensor_max_range_available, S_IRUGO,
+ srf08_show_range_mm_available, NULL, 0);
+
+static ssize_t srf08_show_range_mm(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct srf08_data *data = iio_priv(indio_dev);
+
+ return sprintf(buf, "%d.%03d\n", data->range_mm / 1000,
+ data->range_mm % 1000);
+}
+
+/*
+ * set the range of the sensor to an even multiple of 43 mm
+ * which corresponds to 1 LSB in the register
+ *
+ * register value corresponding range
+ * 0x00 43 mm
+ * 0x01 86 mm
+ * 0x02 129 mm
+ * ...
+ * 0xFF 11008 mm
+ */
+static ssize_t srf08_write_range_mm(struct srf08_data *data, unsigned int val)
+{
+ int ret;
+ struct i2c_client *client = data->client;
+ unsigned int mod;
+ u8 regval;
+
+ ret = val / 43 - 1;
+ mod = val % 43;
+
+ if (mod || (ret < 0) || (ret > 255))
+ return -EINVAL;
+
+ regval = ret;
+
+ mutex_lock(&data->lock);
+
+ ret = i2c_smbus_write_byte_data(client, SRF08_WRITE_RANGE, regval);
+ if (ret < 0) {
+ dev_err(&client->dev, "write_range - err: %d\n", ret);
+ mutex_unlock(&data->lock);
+ return ret;
+ }
+
+ data->range_mm = val;
+
+ mutex_unlock(&data->lock);
+
+ return 0;
+}
+
+static ssize_t srf08_store_range_mm(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct srf08_data *data = iio_priv(indio_dev);
+ int ret;
+ int integer, fract;
+
+ ret = iio_str_to_fixpoint(buf, 100, &integer, &fract);
+ if (ret)
+ return ret;
+
+ ret = srf08_write_range_mm(data, integer * 1000 + fract);
+ if (ret < 0)
+ return ret;
+
+ return len;
+}
+
+static IIO_DEVICE_ATTR(sensor_max_range, S_IRUGO | S_IWUSR,
+ srf08_show_range_mm, srf08_store_range_mm, 0);
+
+static ssize_t srf08_show_sensitivity_available(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int i, len = 0;
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct srf08_data *data = iio_priv(indio_dev);
+
+ for (i = 0; i < data->chip_info->num_sensitivity_avail; i++)
+ if (data->chip_info->sensitivity_avail[i])
+ len += sprintf(buf + len, "%d ",
+ data->chip_info->sensitivity_avail[i]);
+
+ len += sprintf(buf + len, "\n");
+
+ return len;
+}
+
+static IIO_DEVICE_ATTR(sensor_sensitivity_available, S_IRUGO,
+ srf08_show_sensitivity_available, NULL, 0);
+
+static ssize_t srf08_show_sensitivity(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct srf08_data *data = iio_priv(indio_dev);
+ int len;
+
+ len = sprintf(buf, "%d\n", data->sensitivity);
+
+ return len;
+}
+
+static ssize_t srf08_write_sensitivity(struct srf08_data *data,
+ unsigned int val)
+{
+ struct i2c_client *client = data->client;
+ int ret, i;
+ u8 regval;
+
+ if (!val)
+ return -EINVAL;
+
+ for (i = 0; i < data->chip_info->num_sensitivity_avail; i++)
+ if (val && (val == data->chip_info->sensitivity_avail[i])) {
+ regval = i;
+ break;
+ }
+
+ if (i >= data->chip_info->num_sensitivity_avail)
+ return -EINVAL;
+
+ mutex_lock(&data->lock);
+
+ ret = i2c_smbus_write_byte_data(client, SRF08_WRITE_MAX_GAIN, regval);
+ if (ret < 0) {
+ dev_err(&client->dev, "write_sensitivity - err: %d\n", ret);
+ mutex_unlock(&data->lock);
+ return ret;
+ }
+
+ data->sensitivity = val;
+
+ mutex_unlock(&data->lock);
+
+ return 0;
+}
+
+static ssize_t srf08_store_sensitivity(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct srf08_data *data = iio_priv(indio_dev);
+ int ret;
+ unsigned int val;
+
+ ret = kstrtouint(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ ret = srf08_write_sensitivity(data, val);
+ if (ret < 0)
+ return ret;
+
+ return len;
+}
+
+static IIO_DEVICE_ATTR(sensor_sensitivity, S_IRUGO | S_IWUSR,
+ srf08_show_sensitivity, srf08_store_sensitivity, 0);
+
+static struct attribute *srf08_attributes[] = {
+ &iio_dev_attr_sensor_max_range.dev_attr.attr,
+ &iio_dev_attr_sensor_max_range_available.dev_attr.attr,
+ &iio_dev_attr_sensor_sensitivity.dev_attr.attr,
+ &iio_dev_attr_sensor_sensitivity_available.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group srf08_attribute_group = {
+ .attrs = srf08_attributes,
+};
+
+static const struct iio_chan_spec srf08_channels[] = {
+ {
+ .type = IIO_DISTANCE,
+ .info_mask_separate =
+ BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .scan_index = 0,
+ .scan_type = {
+ .sign = 's',
+ .realbits = 16,
+ .storagebits = 16,
+ .endianness = IIO_CPU,
+ },
+ },
+ IIO_CHAN_SOFT_TIMESTAMP(1),
+};
+
+static const struct iio_info srf08_info = {
+ .read_raw = srf08_read_raw,
+ .attrs = &srf08_attribute_group,
+};
+
+/*
+ * srf02 don't have an adjustable range or sensitivity,
+ * so we don't need attributes at all
+ */
+static const struct iio_info srf02_info = {
+ .read_raw = srf08_read_raw,
+};
+
+static int srf08_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct iio_dev *indio_dev;
+ struct srf08_data *data;
+ int ret;
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_READ_BYTE_DATA |
+ I2C_FUNC_SMBUS_WRITE_BYTE_DATA |
+ I2C_FUNC_SMBUS_READ_WORD_DATA))
+ return -ENODEV;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ data = iio_priv(indio_dev);
+ i2c_set_clientdata(client, indio_dev);
+ data->client = client;
+ data->sensor_type = (enum srf08_sensor_type)id->driver_data;
+
+ switch (data->sensor_type) {
+ case SRF02:
+ data->chip_info = &srf02_chip_info;
+ indio_dev->info = &srf02_info;
+ break;
+ case SRF08:
+ data->chip_info = &srf08_chip_info;
+ indio_dev->info = &srf08_info;
+ break;
+ case SRF10:
+ data->chip_info = &srf10_chip_info;
+ indio_dev->info = &srf08_info;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ indio_dev->name = id->name;
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = srf08_channels;
+ indio_dev->num_channels = ARRAY_SIZE(srf08_channels);
+
+ mutex_init(&data->lock);
+
+ ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev,
+ iio_pollfunc_store_time, srf08_trigger_handler, NULL);
+ if (ret < 0) {
+ dev_err(&client->dev, "setup of iio triggered buffer failed\n");
+ return ret;
+ }
+
+ if (data->chip_info->range_default) {
+ /*
+ * set default range of device in mm here
+ * these register values cannot be read from the hardware
+ * therefore set driver specific default values
+ *
+ * srf02 don't have a default value so it'll be omitted
+ */
+ ret = srf08_write_range_mm(data,
+ data->chip_info->range_default);
+ if (ret < 0)
+ return ret;
+ }
+
+ if (data->chip_info->sensitivity_default) {
+ /*
+ * set default sensitivity of device here
+ * these register values cannot be read from the hardware
+ * therefore set driver specific default values
+ *
+ * srf02 don't have a default value so it'll be omitted
+ */
+ ret = srf08_write_sensitivity(data,
+ data->chip_info->sensitivity_default);
+ if (ret < 0)
+ return ret;
+ }
+
+ return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static const struct of_device_id of_srf08_match[] = {
+ { .compatible = "devantech,srf02", (void *)SRF02},
+ { .compatible = "devantech,srf08", (void *)SRF08},
+ { .compatible = "devantech,srf10", (void *)SRF10},
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, of_srf08_match);
+
+static const struct i2c_device_id srf08_id[] = {
+ { "srf02", SRF02 },
+ { "srf08", SRF08 },
+ { "srf10", SRF10 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, srf08_id);
+
+static struct i2c_driver srf08_driver = {
+ .driver = {
+ .name = "srf08",
+ .of_match_table = of_srf08_match,
+ },
+ .probe = srf08_probe,
+ .id_table = srf08_id,
+};
+module_i2c_driver(srf08_driver);
+
+MODULE_AUTHOR("Andreas Klinger <ak@it-klinger.de>");
+MODULE_DESCRIPTION("Devantech SRF02/SRF08/SRF10 i2c ultrasonic ranger driver");
+MODULE_LICENSE("GPL");