Minimal implementation of an IIO driver for the Domintech DMARD09 3-axis
accelerometer. Only supports reading the x,y,z axes at the moment.
Implementation based on the Android driver from the Acer Liquid E2
kernel sources.
Signed-off-by: Jelle van der Waa <jelle@xxxxxxxx>
---
Changes in v2:
- Use ARRAY_SIZE instead of the #define DMARD09_AXES_NUM
- Use a function-like macro to generate the channel structs
- Remove duplicate 3-axis in driver description
- Don't initialize the u8 buf
- Use devm_iio_device_register and remove the now unrequired
dmard09_remove.
- Remove device from dmard09_data struct and use the client member to retrieve
the device.
- Describe the read strategy of the read_raw function
- Simplify reading the X, Y, Z axis, by introducing DMARD09_AXIS_N_OFFSET,
which removes the required if statements.
- Log the _STAT address in the dev_error in the dmard09_read_raw function.
---
.../devicetree/bindings/iio/accel/dmard09.txt | 13 ++
drivers/iio/accel/Kconfig | 10 ++
drivers/iio/accel/Makefile | 1 +
drivers/iio/accel/dmard09.c | 149 +++++++++++++++++++++
4 files changed, 173 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/accel/dmard09.txt
create mode 100644 drivers/iio/accel/dmard09.c
diff --git a/Documentation/devicetree/bindings/iio/accel/dmard09.txt b/Documentation/devicetree/bindings/iio/accel/dmard09.txt
new file mode 100644
index 0000000..69b2a03
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/accel/dmard09.txt
@@ -0,0 +1,13 @@
+Domintech DMARD09 accelerometer devicetree bindings
+
+Required properties:
+
+ - compatible : should be "domintech,dmard09"
+ - reg : the I2C address of the sensor
+
+Example:
+
+dmard09@0x1d {
+ compatible = "domintech,dmard09";
+ reg = <0x1d>;
+};
diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index e4a758c..4b886fb 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -40,6 +40,16 @@ config BMC150_ACCEL_SPI
tristate
select REGMAP_SPI
+config DMARD09
+ tristate "Domintech DMARD09 3-axis Accelerometer Driver"
+ depends on I2C
+ help
+ Say yes here to get support for the Domintech DMARD09 3-axis
+ accelerometer.
+
+ Choosing M will build the driver as a module. If so, the module
+ will be called dmard09.
+
config HID_SENSOR_ACCEL_3D
depends on HID_SENSOR_HUB
select IIO_BUFFER
diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
index 71b6794..b1022a0 100644
--- a/drivers/iio/accel/Makefile
+++ b/drivers/iio/accel/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_BMA180) += bma180.o
obj-$(CONFIG_BMC150_ACCEL) += bmc150-accel-core.o
obj-$(CONFIG_BMC150_ACCEL_I2C) += bmc150-accel-i2c.o
obj-$(CONFIG_BMC150_ACCEL_SPI) += bmc150-accel-spi.o
+obj-$(CONFIG_DMARD09) += dmard09.o
obj-$(CONFIG_HID_SENSOR_ACCEL_3D) += hid-sensor-accel-3d.o
obj-$(CONFIG_KXCJK1013) += kxcjk-1013.o
obj-$(CONFIG_KXSD9) += kxsd9.o
diff --git a/drivers/iio/accel/dmard09.c b/drivers/iio/accel/dmard09.c
new file mode 100644
index 0000000..8fba368
--- /dev/null
+++ b/drivers/iio/accel/dmard09.c
@@ -0,0 +1,149 @@
+/*
+ * IIO driver for the 3-axis accelerometer Domintech DMARD09.
+ *
+ * Copyright (c) 2016, Jelle van der Waa <jelle@xxxxxxxx>
+ *
+ * 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 <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;
+
+ 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;
+ }
+
+ *val = (s16)((buf[chan->address+1] << 8) | buf[chan->address]);
+
+ 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@xxxxxxxx>");
+MODULE_DESCRIPTION("DMARD09 3-axis accelerometer driver");
+MODULE_LICENSE("GPL");
--
2.9.0
--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
