[PATCH 2/2] iio: accel: Add support for Domintech DMARD06 accelerometer

From: Aleksei Mamlin
Date: Thu Jul 21 2016 - 16:33:38 EST

This patch add support for Domintech DMARD06 accelerometer.

Domintech DMARD06 is a low-g tri-axial digital accelerometer for
cost-sensitive consumer application.

Signed-off-by: Aleksei Mamlin <mamlinav@xxxxxxxxx>
---
.../devicetree/bindings/iio/accel/dmard06.txt | 17 ++
drivers/iio/accel/Kconfig | 11 ++
drivers/iio/accel/Makefile | 1 +
drivers/iio/accel/dmard06.c | 219 +++++++++++++++++++++
4 files changed, 248 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/accel/dmard06.txt
create mode 100644 drivers/iio/accel/dmard06.c

diff --git a/Documentation/devicetree/bindings/iio/accel/dmard06.txt b/Documentation/devicetree/bindings/iio/accel/dmard06.txt
new file mode 100644
index 0000000..cc2231a
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/accel/dmard06.txt
@@ -0,0 +1,17 @@
+Device tree bindings for Domintech DMARD06 acceletometer
+
+Required properties:
+ - compatible : Should be "domintech,dmard06"
+ - reg : I2C address of the chip. Should be 0x1c
+
+Example:
+ &i2c1 {
+ /* ... */
+
+ accelerometer@1c {
+ compatible = "domintech,dmard06";
+ reg = <0x1c>;
+ };
+
+ /* ... */
+ };
diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index e4a758c..abc8536 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -40,6 +40,17 @@ config BMC150_ACCEL_SPI
tristate
select REGMAP_SPI

+config DMARD06
+ tristate "Domintech DMARD06 Digital Accelerometer Driver"
+ depends on OF || COMPILE_TEST
+ depends on I2C
+ help
+ Say yes here to build support for the Domintech DMARD06 low-g
+ tri-axial digital accelerometer connected via an I2C bus.
+
+ To compile this driver as a module, choose M here: the
+ module will be called dmard06.
+
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..a96b269 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-$(CONFIG_DMARD06) += dmard06.o
obj-$(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/dmard06.c b/drivers/iio/accel/dmard06.c
new file mode 100644
index 0000000..433e430
--- /dev/null
+++ b/drivers/iio/accel/dmard06.c
@@ -0,0 +1,219 @@
+/*
+ * IIO driver for Domintech DMARD06 accelerometer
+ *
+ * Copyright (C) 2016 Aleksei Mamlin <mamlinav@xxxxxxxxx>
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+
+struct dmard06_data {
+ struct i2c_client *client;
+};
+
+#define DMARD06_DRV_NAME "dmard06"
+
+/* Device data registers */
+#define DMARD06_CHIP_ID_REG 0x0f
+#define DMARD06_TOUT_REG 0x40
+#define DMARD06_XOUT_REG 0x41
+#define DMARD06_YOUT_REG 0x42
+#define DMARD06_ZOUT_REG 0x43
+
+/* Device ID value */
+#define DMARD06_CHIP_ID 0x06
+
+/* Device values */
+#define DMARD06_AXIS_MAX_VAL 64
+#define DMARD06_AXIS_SCALE_VAL 31250
+#define DMARD06_TEMP_CENTER_VAL 25
+
+static int dmard06_i2c_read(struct i2c_client *client, u8 reg, u8 *buf)
+{
+ int error;
+
+ error = i2c_master_send(client, &reg, 1);
+ if (unlikely(error < 0))
+ return error;
+
+ error = i2c_master_recv(client, buf, 1);
+ if (unlikely(error < 0))
+ return error;
+ return 0;
+}
+
+static int dmard06_read_chip_id(struct dmard06_data *dmard06)
+{
+ u8 buf;
+ u8 chip_id;
+ int error;
+
+ error = dmard06_i2c_read(dmard06->client, DMARD06_CHIP_ID_REG, &buf);
+ if (error) {
+ dev_err(&dmard06->client->dev, "Failed to read chip id: %d\n",
+ error);
+ return error;
+ }
+
+ chip_id = (buf & 0x00ff);
+ if (chip_id != DMARD06_CHIP_ID) {
+ dev_err(&dmard06->client->dev, "Invalid chip id: %02x\n",
+ chip_id);
+ return -EINVAL;
+ }
+
+ dev_info(&dmard06->client->dev, "Found DMARD%02x chip\n", chip_id);
+
+ return 0;
+}
+
+static int dmard06_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct dmard06_data *dmard06 = iio_priv(indio_dev);
+ u8 buf;
+ bool reversed;
+ int error;
+ int tmp;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ error = dmard06_i2c_read(dmard06->client, chan->address, &buf);
+ if (error) {
+ dev_err(&dmard06->client->dev,
+ "Failed to read data %d\n", error);
+ return error;
+ }
+
+ reversed = (buf >> 7) & 1;
+ tmp = (int)((buf & 0x7f) >> 1);
+
+ switch (chan->type) {
+ case IIO_ACCEL:
+ *val = reversed ? (tmp - DMARD06_AXIS_MAX_VAL) : tmp;
+ return IIO_VAL_INT;
+ case IIO_TEMP:
+ *val = reversed ? -tmp : tmp;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+ case IIO_CHAN_INFO_OFFSET:
+ switch (chan->type) {
+ case IIO_TEMP:
+ *val = DMARD06_TEMP_CENTER_VAL;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->type) {
+ case IIO_ACCEL:
+ *val = 0;
+ *val2 = DMARD06_AXIS_SCALE_VAL;
+ return IIO_VAL_INT_PLUS_MICRO;
+ default:
+ return -EINVAL;
+ }
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info dmard06_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = dmard06_read_raw,
+};
+
+#define DMARD06_ACCEL_CHANNEL(_axis, reg) { \
+ .type = IIO_ACCEL, \
+ .address = reg, \
+ .channel2 = IIO_MOD_##_axis, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+ .modified = 1, \
+}
+
+#define DMARD06_TEMP_CHANNEL(reg) { \
+ .type = IIO_TEMP, \
+ .address = reg, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+ BIT(IIO_CHAN_INFO_OFFSET), \
+}
+
+static const struct iio_chan_spec dmard06_channels[] = {
+ DMARD06_ACCEL_CHANNEL(X, DMARD06_XOUT_REG),
+ DMARD06_ACCEL_CHANNEL(Y, DMARD06_YOUT_REG),
+ DMARD06_ACCEL_CHANNEL(Z, DMARD06_ZOUT_REG),
+ DMARD06_TEMP_CHANNEL(DMARD06_TOUT_REG),
+};
+
+static int dmard06_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ int error;
+ struct iio_dev *indio_dev;
+ struct dmard06_data *dmard06;
+
+ dev_dbg(&client->dev, "I2C Address: 0x%02x\n", client->addr);
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+ dev_err(&client->dev, "I2C check functionality failed\n");
+ return -ENXIO;
+ }
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*dmard06));
+ if (!indio_dev) {
+ dev_err(&client->dev, "Failed to allocate iio device\n");
+ return -ENOMEM;
+ }
+
+ dmard06 = iio_priv(indio_dev);
+ dmard06->client = client;
+
+ error = dmard06_read_chip_id(dmard06);
+ if (error)
+ return error;
+
+ i2c_set_clientdata(client, indio_dev);
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->name = DMARD06_DRV_NAME;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = dmard06_channels;
+ indio_dev->num_channels = ARRAY_SIZE(dmard06_channels);
+ indio_dev->info = &dmard06_info;
+
+ return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static const struct i2c_device_id dmard06_id[] = {
+ { "dmard06", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, dmard06_id);
+
+static const struct of_device_id dmard06_of_match[] = {
+ { .compatible = "domintech,dmard06" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, dmard06_of_match);
+
+static struct i2c_driver dmard06_driver = {
+ .probe = dmard06_probe,
+ .id_table = dmard06_id,
+ .driver = {
+ .name = DMARD06_DRV_NAME,
+ .of_match_table = of_match_ptr(dmard06_of_match),
+ },
+};
+module_i2c_driver(dmard06_driver);
+
+MODULE_AUTHOR("Aleksei Mamlin <mamlinav@xxxxxxxxx>");
+MODULE_DESCRIPTION("Domintech DMARD06 accelerometer driver");
+MODULE_LICENSE("GPL v2");
--
2.7.3