1 files changed, 157 insertions, 0 deletions

diff --git a/drivers/iio/accel/dmard09.c b/drivers/iio/accel/dmard09.c
new file mode 100644
index 000000000000..d3a28f96565c
--- /dev/null
+++ b/drivers/iio/accel/dmard09.c
@@ -0,0 +1,157 @@
+/*
+ * IIO driver for the 3-axis accelerometer Domintech DMARD09.
+ *
+ * Copyright (c) 2016, Jelle van der Waa <jelle@vdwaa.nl>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <asm/unaligned.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+
+#define DMARD09_DRV_NAME        "dmard09"
+
+#define DMARD09_REG_CHIPID      0x18
+#define DMARD09_REG_STAT        0x0A
+#define DMARD09_REG_X           0x0C
+#define DMARD09_REG_Y           0x0E
+#define DMARD09_REG_Z           0x10
+#define DMARD09_CHIPID          0x95
+
+#define DMARD09_BUF_LEN 8
+#define DMARD09_AXIS_X 0
+#define DMARD09_AXIS_Y 1
+#define DMARD09_AXIS_Z 2
+#define DMARD09_AXIS_X_OFFSET ((DMARD09_AXIS_X + 1) * 2)
+#define DMARD09_AXIS_Y_OFFSET ((DMARD09_AXIS_Y + 1 )* 2)
+#define DMARD09_AXIS_Z_OFFSET ((DMARD09_AXIS_Z + 1) * 2)
+
+struct dmard09_data {
+        struct i2c_client *client;
+};
+
+#define DMARD09_CHANNEL(_axis, offset) {                        \
+        .type = IIO_ACCEL,                                      \
+        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
+        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
+        .modified = 1,                                          \
+        .address = offset,                                      \
+        .channel2 = IIO_MOD_##_axis,                            \
+}
+
+static const struct iio_chan_spec dmard09_channels[] = {
+        DMARD09_CHANNEL(X, DMARD09_AXIS_X_OFFSET),
+        DMARD09_CHANNEL(Y, DMARD09_AXIS_Y_OFFSET),
+        DMARD09_CHANNEL(Z, DMARD09_AXIS_Z_OFFSET),
+};
+
+static int dmard09_read_raw(struct iio_dev *indio_dev,
+                            struct iio_chan_spec const *chan,
+                            int *val, int *val2, long mask)
+{
+        struct dmard09_data *data = iio_priv(indio_dev);
+        u8 buf[DMARD09_BUF_LEN];
+        int ret;
+        s16 accel;
+
+        switch (mask) {
+        case IIO_CHAN_INFO_RAW:
+                /*
+                 * Read from the DMAR09_REG_STAT register, since the chip
+                 * caches reads from the individual X, Y, Z registers.
+                 */
+                ret = i2c_smbus_read_i2c_block_data(data->client,
+                                                    DMARD09_REG_STAT,
+                                                    DMARD09_BUF_LEN, buf);
+                if (ret < 0) {
+                        dev_err(&data->client->dev, "Error reading reg %d\n",
+                                DMARD09_REG_STAT);
+                        return ret;
+                }
+
+                accel = get_unaligned_le16(&buf[chan->address]);
+
+                /* Remove lower 3 bits and sign extend */
+                accel <<= 4;
+                accel >>= 7;
+
+                *val = accel;
+
+                return IIO_VAL_INT;
+        default:
+                return -EINVAL;
+        }
+}
+
+static const struct iio_info dmard09_info = {
+        .driver_module  = THIS_MODULE,
+        .read_raw       = dmard09_read_raw,
+};
+
+static int dmard09_probe(struct i2c_client *client,
+                        const struct i2c_device_id *id)
+{
+        int ret;
+        struct iio_dev *indio_dev;
+        struct dmard09_data *data;
+
+        indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+        if (!indio_dev) {
+                dev_err(&client->dev, "iio allocation failed\n");
+                return -ENOMEM;
+        }
+
+        data = iio_priv(indio_dev);
+        data->client = client;
+
+        ret = i2c_smbus_read_byte_data(data->client, DMARD09_REG_CHIPID);
+        if (ret < 0) {
+                dev_err(&client->dev, "Error reading chip id %d\n", ret);
+                return ret;
+        }
+
+        if (ret != DMARD09_CHIPID) {
+                dev_err(&client->dev, "Invalid chip id %d\n", ret);
+                return -ENODEV;
+        }
+
+        i2c_set_clientdata(client, indio_dev);
+        indio_dev->dev.parent = &client->dev;
+        indio_dev->name = DMARD09_DRV_NAME;
+        indio_dev->modes = INDIO_DIRECT_MODE;
+        indio_dev->channels = dmard09_channels;
+        indio_dev->num_channels = ARRAY_SIZE(dmard09_channels);
+        indio_dev->info = &dmard09_info;
+
+        return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static const struct i2c_device_id dmard09_id[] = {
+        { "dmard09", 0},
+        { },
+};
+
+MODULE_DEVICE_TABLE(i2c, dmard09_id);
+
+static struct i2c_driver dmard09_driver = {
+        .driver = {
+                .name = DMARD09_DRV_NAME
+        },
+        .probe = dmard09_probe,
+        .id_table = dmard09_id,
+};
+
+module_i2c_driver(dmard09_driver);
+
+MODULE_AUTHOR("Jelle van der Waa <jelle@vdwaa.nl>");
+MODULE_DESCRIPTION("DMARD09 3-axis accelerometer driver");
+MODULE_LICENSE("GPL");