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Diffstat (limited to 'drivers/iio/pressure/mpl115_spi.c')
-rw-r--r--drivers/iio/pressure/mpl115_spi.c104
1 files changed, 104 insertions, 0 deletions
diff --git a/drivers/iio/pressure/mpl115_spi.c b/drivers/iio/pressure/mpl115_spi.c
new file mode 100644
index 000000000..7feec87e2
--- /dev/null
+++ b/drivers/iio/pressure/mpl115_spi.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Freescale MPL115A1 pressure/temperature sensor
+ *
+ * Copyright (c) 2016 Akinobu Mita <akinobu.mita@gmail.com>
+ *
+ * Datasheet: http://www.nxp.com/files/sensors/doc/data_sheet/MPL115A1.pdf
+ */
+
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+
+#include "mpl115.h"
+
+#define MPL115_SPI_WRITE(address) ((address) << 1)
+#define MPL115_SPI_READ(address) (0x80 | (address) << 1)
+
+struct mpl115_spi_buf {
+ u8 tx[4];
+ u8 rx[4];
+};
+
+static int mpl115_spi_init(struct device *dev)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ struct mpl115_spi_buf *buf;
+
+ buf = devm_kzalloc(dev, sizeof(*buf), GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ spi_set_drvdata(spi, buf);
+
+ return 0;
+}
+
+static int mpl115_spi_read(struct device *dev, u8 address)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ struct mpl115_spi_buf *buf = spi_get_drvdata(spi);
+ struct spi_transfer xfer = {
+ .tx_buf = buf->tx,
+ .rx_buf = buf->rx,
+ .len = 4,
+ };
+ int ret;
+
+ buf->tx[0] = MPL115_SPI_READ(address);
+ buf->tx[2] = MPL115_SPI_READ(address + 1);
+
+ ret = spi_sync_transfer(spi, &xfer, 1);
+ if (ret)
+ return ret;
+
+ return (buf->rx[1] << 8) | buf->rx[3];
+}
+
+static int mpl115_spi_write(struct device *dev, u8 address, u8 value)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ struct mpl115_spi_buf *buf = spi_get_drvdata(spi);
+ struct spi_transfer xfer = {
+ .tx_buf = buf->tx,
+ .len = 2,
+ };
+
+ buf->tx[0] = MPL115_SPI_WRITE(address);
+ buf->tx[1] = value;
+
+ return spi_sync_transfer(spi, &xfer, 1);
+}
+
+static const struct mpl115_ops mpl115_spi_ops = {
+ .init = mpl115_spi_init,
+ .read = mpl115_spi_read,
+ .write = mpl115_spi_write,
+};
+
+static int mpl115_spi_probe(struct spi_device *spi)
+{
+ const struct spi_device_id *id = spi_get_device_id(spi);
+
+ return mpl115_probe(&spi->dev, id->name, &mpl115_spi_ops);
+}
+
+static const struct spi_device_id mpl115_spi_ids[] = {
+ { "mpl115", 0 },
+ {}
+};
+MODULE_DEVICE_TABLE(spi, mpl115_spi_ids);
+
+static struct spi_driver mpl115_spi_driver = {
+ .driver = {
+ .name = "mpl115",
+ },
+ .probe = mpl115_spi_probe,
+ .id_table = mpl115_spi_ids,
+};
+module_spi_driver(mpl115_spi_driver);
+
+MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
+MODULE_DESCRIPTION("Freescale MPL115A1 pressure/temperature driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(IIO_MPL115);