iio: pressure: Add driver for Sensirion SDP500

Sensirion SDP500 is a digital differential pressure sensor. The sensor is
accessed over I2C.

Signed-off-by: Petar Stoykov <pd.pstoykov@gmail.com>
Link: https://patch.msgid.link/20240725-mainline_sdp500-v4-2-ea2f5b189958@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/pressure/Kconfig b/drivers/iio/pressure/Kconfig
index 0b5406a3f85dc58b269f8084c36bd160261be44a..ce369dbb17fc1551f2e139db340c7822dfeab030 100644 (file)
--- a/drivers/iio/pressure/Kconfig
+++ b/drivers/iio/pressure/Kconfig
@@ -250,6 +250,15 @@ config MS5637
          This driver can also be built as a module. If so, the module will
          be called ms5637.
 
+config SDP500
+       tristate "Sensirion SDP500 differential pressure sensor I2C driver"
+       depends on I2C
+       help
+         Say Y here to build support for Sensirion SDP500 differential pressure
+         sensor I2C driver.
+         To compile this driver as a module, choose M here: the core module
+         will be called sdp500.
+
 config IIO_ST_PRESS
        tristate "STMicroelectronics pressure sensor Driver"
        depends on (I2C || SPI_MASTER) && SYSFS

diff --git a/drivers/iio/pressure/Makefile b/drivers/iio/pressure/Makefile
index a93709e357607d3704744eda98269f2b60e955e9..6482288e07ee4f22ae380ad0da0fc0b0c2f9ca05 100644 (file)
--- a/drivers/iio/pressure/Makefile
+++ b/drivers/iio/pressure/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_MS5611) += ms5611_core.o
 obj-$(CONFIG_MS5611_I2C) += ms5611_i2c.o
 obj-$(CONFIG_MS5611_SPI) += ms5611_spi.o
 obj-$(CONFIG_MS5637) += ms5637.o
+obj-$(CONFIG_SDP500) += sdp500.o
 obj-$(CONFIG_IIO_ST_PRESS) += st_pressure.o
 st_pressure-y := st_pressure_core.o
 st_pressure-$(CONFIG_IIO_BUFFER) += st_pressure_buffer.o

diff --git a/drivers/iio/pressure/sdp500.c b/drivers/iio/pressure/sdp500.c
new file mode 100644 (file)
index 0000000..6ff32e3
--- /dev/null
+++ b/drivers/iio/pressure/sdp500.c
@@ -0,0 +1,156 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for Sensirion sdp500 and sdp510 pressure sensors
+ *
+ * Datasheet: https://sensirion.com/resource/datasheet/sdp600
+ */
+
+#include <linux/i2c.h>
+#include <linux/crc8.h>
+#include <linux/iio/iio.h>
+#include <linux/mod_devicetable.h>
+#include <linux/regulator/consumer.h>
+#include <asm/unaligned.h>
+
+#define SDP500_CRC8_POLYNOMIAL  0x31   /* x8+x5+x4+1 (normalized to 0x31) */
+#define SDP500_READ_SIZE        3
+
+#define SDP500_I2C_START_MEAS 0xF1
+
+struct sdp500_data {
+       struct device *dev;
+};
+
+DECLARE_CRC8_TABLE(sdp500_crc8_table);
+
+static int sdp500_start_measurement(struct sdp500_data *data)
+{
+       struct i2c_client *client = to_i2c_client(data->dev);
+
+       return i2c_smbus_write_byte(client, SDP500_I2C_START_MEAS);
+}
+
+static const struct iio_chan_spec sdp500_channels[] = {
+       {
+               .type = IIO_PRESSURE,
+               .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+                       BIT(IIO_CHAN_INFO_SCALE),
+       },
+};
+
+static int sdp500_read_raw(struct iio_dev *indio_dev,
+                         struct iio_chan_spec const *chan,
+                         int *val, int *val2, long mask)
+{
+       int ret;
+       u8 rxbuf[SDP500_READ_SIZE];
+       u8 received_crc, calculated_crc;
+       struct sdp500_data *data = iio_priv(indio_dev);
+       struct i2c_client *client = to_i2c_client(data->dev);
+
+       switch (mask) {
+       case IIO_CHAN_INFO_RAW:
+               ret = i2c_master_recv(client, rxbuf, SDP500_READ_SIZE);
+               if (ret < 0) {
+                       dev_err(data->dev, "Failed to receive data");
+                       return ret;
+               }
+               if (ret != SDP500_READ_SIZE) {
+                       dev_err(data->dev, "Data is received wrongly");
+                       return -EIO;
+               }
+
+               received_crc = rxbuf[2];
+               calculated_crc = crc8(sdp500_crc8_table, rxbuf,
+                                     sizeof(rxbuf) - 1, 0x00);
+               if (received_crc != calculated_crc) {
+                       dev_err(data->dev,
+                               "calculated crc = 0x%.2X, received 0x%.2X",
+                               calculated_crc, received_crc);
+                       return -EIO;
+               }
+
+               *val = get_unaligned_be16(rxbuf);
+               return IIO_VAL_INT;
+       case IIO_CHAN_INFO_SCALE:
+               *val = 1;
+               *val2 = 60;
+
+               return IIO_VAL_FRACTIONAL;
+       default:
+               return -EINVAL;
+       }
+}
+
+static const struct iio_info sdp500_info = {
+       .read_raw = &sdp500_read_raw,
+};
+
+static int sdp500_probe(struct i2c_client *client)
+{
+       struct iio_dev *indio_dev;
+       struct sdp500_data *data;
+       struct device *dev = &client->dev;
+       int ret;
+       u8 rxbuf[SDP500_READ_SIZE];
+
+       ret = devm_regulator_get_enable(dev, "vdd");
+       if (ret)
+               return dev_err_probe(dev, ret,
+                       "Failed to get and enable regulator\n");
+
+       indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+       if (!indio_dev)
+               return -ENOMEM;
+
+       /* has to be done before the first i2c communication */
+       crc8_populate_msb(sdp500_crc8_table, SDP500_CRC8_POLYNOMIAL);
+
+       data = iio_priv(indio_dev);
+       data->dev = dev;
+
+       indio_dev->name = "sdp500";
+       indio_dev->channels = sdp500_channels;
+       indio_dev->info = &sdp500_info;
+       indio_dev->modes = INDIO_DIRECT_MODE;
+       indio_dev->num_channels = ARRAY_SIZE(sdp500_channels);
+
+       ret = sdp500_start_measurement(data);
+       if (ret)
+               return dev_err_probe(dev, ret, "Failed to start measurement");
+
+       /* First measurement is not correct, read it out to get rid of it */
+       i2c_master_recv(client, rxbuf, SDP500_READ_SIZE);
+
+       ret = devm_iio_device_register(dev, indio_dev);
+       if (ret)
+               return dev_err_probe(dev, ret, "Failed to register indio_dev");
+
+       return 0;
+}
+
+static const struct i2c_device_id sdp500_id[] = {
+       { "sdp500" },
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, sdp500_id);
+
+static const struct of_device_id sdp500_of_match[] = {
+       { .compatible = "sensirion,sdp500" },
+       { }
+};
+MODULE_DEVICE_TABLE(of, sdp500_of_match);
+
+static struct i2c_driver sdp500_driver = {
+       .driver = {
+               .name = "sensirion,sdp500",
+               .of_match_table = sdp500_of_match,
+       },
+       .probe = sdp500_probe,
+       .id_table = sdp500_id,
+};
+module_i2c_driver(sdp500_driver);
+
+MODULE_AUTHOR("Thomas Sioutas <thomas.sioutas@prodrive-technologies.com>");
+MODULE_DESCRIPTION("Driver for Sensirion SDP500 differential pressure sensor");
+MODULE_LICENSE("GPL");