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Subject[PATCH v2] iio: imu: Add support for Kionix KMX61 sensor
Date
Minimal implementation for KMX61 6-axis accelerometer/magnetometer. It exports
raw accel/magn readings together with scale and sampling frequency.

Datasheet will be available at:
http://www.kionix.com/6-axis-accelerometer-magnetometer/kmx61

Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
---
Changes since v1:
* serialize non-atomic operations with a mutex (set_odr/get_odr, set_scale).
* no need to protect reading info scale because it reduces to reading an u8
which should be atomic on all arches
* *note* - read_measurment is an atomic operation

drivers/iio/imu/Kconfig | 9 +
drivers/iio/imu/Makefile | 2 +
drivers/iio/imu/kmx61.c | 590 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 601 insertions(+)
create mode 100644 drivers/iio/imu/kmx61.c

diff --git a/drivers/iio/imu/Kconfig b/drivers/iio/imu/Kconfig
index 2b0e451..d675f43 100644
--- a/drivers/iio/imu/Kconfig
+++ b/drivers/iio/imu/Kconfig
@@ -25,6 +25,15 @@ config ADIS16480
Say yes here to build support for Analog Devices ADIS16375, ADIS16480,
ADIS16485, ADIS16488 inertial sensors.

+config KMX61
+ tristate "Kionix KMX61 6-axis accelerometer and magnetometer"
+ depends on I2C
+ help
+ Say Y here if you want to build a driver for Kionix KMX61 6-axis accelerometer
+ and magnetometer.
+ To compile this driver as module, choose M here: the module will be called
+ kmx61.
+
source "drivers/iio/imu/inv_mpu6050/Kconfig"

endmenu
diff --git a/drivers/iio/imu/Makefile b/drivers/iio/imu/Makefile
index 114d2c1..e1e6e3d 100644
--- a/drivers/iio/imu/Makefile
+++ b/drivers/iio/imu/Makefile
@@ -14,3 +14,5 @@ adis_lib-$(CONFIG_IIO_ADIS_LIB_BUFFER) += adis_buffer.o
obj-$(CONFIG_IIO_ADIS_LIB) += adis_lib.o

obj-y += inv_mpu6050/
+
+obj-$(CONFIG_KMX61) += kmx61.o
diff --git a/drivers/iio/imu/kmx61.c b/drivers/iio/imu/kmx61.c
new file mode 100644
index 0000000..6135a16
--- /dev/null
+++ b/drivers/iio/imu/kmx61.c
@@ -0,0 +1,590 @@
+/*
+ * KMX61 - Kionix 6-axis Accelerometer/Magnetometer
+ *
+ * Copyright (c) 2014, Intel Corporation.
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License. See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ * IIO driver for KMX61 (7-bit I2C slave address 0x0E or 0x0F).
+ *
+ * TODO: buffer, interrupt, thresholds, acpi, temperature sensor
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define KMX61_DRV_NAME "kmx61"
+
+#define KMX61_REG_WHO_AM_I 0x00
+
+#define KMX61_ACC_XOUT_L 0x0A
+
+#define KMX61_ACC_XOUT_H 0x0B
+#define KMX61_ACC_YOUT_L 0x0C
+#define KMX61_ACC_YOUT_H 0x0D
+#define KMX61_ACC_ZOUT_L 0x0E
+#define KMX61_ACC_ZOUT_H 0x0F
+
+#define KMX61_MAG_XOUT_L 0x12
+
+#define KMX61_MAG_XOUT_H 0x13
+#define KMX61_MAG_YOUT_L 0x14
+#define KMX61_MAG_YOUT_H 0x15
+#define KMX61_MAG_ZOUT_L 0x16
+#define KMX61_MAG_ZOUT_H 0x17
+
+#define KMX61_REG_ODCNTL 0x2C
+
+#define KMX61_REG_STBY 0x29
+#define KMX61_REG_CTRL1 0x2A
+
+#define KMX61_REG_COTR 0x3C
+
+#define KMX61_ACC_STBY_BIT BIT(0)
+#define KMX61_MAG_STBY_BIT BIT(1)
+#define KMX61_ACT_STBY_BIT BIT(7)
+
+#define KMX61_ALL_STBY (KMX61_ACC_STBY_BIT | KMX61_MAG_STBY_BIT)
+
+#define KMX61_REG_CTRL1_GSEL0_SHIFT 0
+#define KMX61_REG_CTRL1_GSEL1_SHIFT 1
+#define KMX61_REG_CTRL1_GSEL0_MASK 0x01
+#define KMX61_REG_CTRL1_GSEL1_MASK 0x02
+
+#define KMX61_REG_CTRL1_BIT_RES BIT(4)
+
+#define KMX61_ACC_ODR_SHIFT 0
+#define KMX61_MAG_ODR_SHIFT 4
+#define KMX61_ACC_ODR_MASK 0x0F
+#define KMX61_MAG_ODR_MASK 0xF0
+
+#define KMX61_CHIP_ID 0x12
+
+struct kmx61_data {
+ struct i2c_client *client;
+ /* serialize access to non-atomic ops, e.g set_mode */
+ struct mutex lock;
+ u8 range;
+ u8 odr_bits;
+};
+
+enum kmx61_range {
+ KMX61_RANGE_2G,
+ KMX61_RANGE_4G,
+ KMX61_RANGE_8G,
+};
+
+enum kmx61_scan {
+ KMX61_SCAN_ACC_X,
+ KMX61_SCAN_ACC_Y,
+ KMX61_SCAN_ACC_Z,
+ KMX61_SCAN_TEMP,
+ KMX61_SCAN_MAG_X,
+ KMX61_SCAN_MAG_Y,
+ KMX61_SCAN_MAG_Z,
+};
+
+static const struct {
+ u16 scale;
+ u8 gsel0;
+ u8 gsel1;
+} kmx61_scale_table[] = {
+ {9582, 0, 0},
+ {19163, 1, 0},
+ {38326, 0, 1},
+};
+
+/* KMX61 devices */
+#define KMX61_ACC 0x01
+#define KMX61_MAG 0x02
+
+static const struct {
+ int val;
+ int val2;
+ int odr_bits;
+} samp_freq_table[] = { {12, 500000, 0x00},
+ {25, 0, 0x01},
+ {50, 0, 0x02},
+ {100, 0, 0x03},
+ {200, 0, 0x04},
+ {400, 0, 0x05},
+ {800, 0, 0x06},
+ {1600, 0, 0x07},
+ {0, 781000, 0x08},
+ {1, 563000, 0x09},
+ {3, 125000, 0x0A},
+ {6, 250000, 0x0B} };
+
+static IIO_CONST_ATTR(accel_scale_available, "0.009582 0.019163 0.038326");
+static IIO_CONST_ATTR(magn_scale_available, "0.001465");
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
+ "0.781000 1.563000 3.125000 6.250000 12.500000 25 50 100 200 400 800");
+
+static struct attribute *kmx61_attributes[] = {
+ &iio_const_attr_accel_scale_available.dev_attr.attr,
+ &iio_const_attr_magn_scale_available.dev_attr.attr,
+ &iio_const_attr_sampling_frequency_available.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group kmx61_attribute_group = {
+ .attrs = kmx61_attributes,
+};
+
+#define KMX61_ACC_CHAN(_axis, _index) { \
+ .type = IIO_ACCEL, \
+ .modified = 1, \
+ .channel2 = IIO_MOD_ ## _axis, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+ .scan_index = _index, \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 12, \
+ .storagebits = 16, \
+ .shift = 4, \
+ .endianness = IIO_BE, \
+ }, \
+}
+
+#define KMX61_MAG_CHAN(_axis, _index) { \
+ .type = IIO_MAGN, \
+ .modified = 1, \
+ .channel2 = IIO_MOD_ ## _axis, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+ .scan_index = _index, \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 14, \
+ .storagebits = 16, \
+ .shift = 2, \
+ .endianness = IIO_BE, \
+ }, \
+}
+
+static const struct iio_chan_spec kmx61_channels[] = {
+ KMX61_ACC_CHAN(X, KMX61_SCAN_ACC_X),
+ KMX61_ACC_CHAN(Y, KMX61_SCAN_ACC_Y),
+ KMX61_ACC_CHAN(Z, KMX61_SCAN_ACC_Z),
+ KMX61_MAG_CHAN(X, KMX61_SCAN_MAG_X),
+ KMX61_MAG_CHAN(Y, KMX61_SCAN_MAG_Y),
+ KMX61_MAG_CHAN(Z, KMX61_SCAN_MAG_Z),
+};
+
+static int kmx61_convert_freq_to_bit(int val, int val2)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(samp_freq_table); i++)
+ if (val == samp_freq_table[i].val &&
+ val2 == samp_freq_table[i].val2)
+ return samp_freq_table[i].odr_bits;
+ return -EINVAL;
+}
+
+static int kmx61_set_mode(struct kmx61_data *data, u8 mode, u8 device)
+{
+ int ret;
+
+ ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_STBY);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "Error reading reg_stby\n");
+ return ret;
+ }
+ if (device & KMX61_ACC) {
+ if (mode & KMX61_ACC_STBY_BIT)
+ ret |= KMX61_ACC_STBY_BIT;
+ else
+ ret &= ~KMX61_ACC_STBY_BIT;
+ }
+
+ if (device & KMX61_MAG) {
+ if (mode & KMX61_MAG_STBY_BIT)
+ ret |= KMX61_MAG_STBY_BIT;
+ else
+ ret &= ~KMX61_MAG_STBY_BIT;
+ }
+
+ ret = i2c_smbus_write_byte_data(data->client, KMX61_REG_STBY, ret);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "Error writing reg_stby\n");
+ return ret;
+ }
+
+ return ret;
+}
+
+static int kmx61_get_mode(struct kmx61_data *data, u8 *mode, u8 device)
+{
+ int ret;
+
+ ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_STBY);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "Error reading reg_stby\n");
+ return ret;
+ }
+ *mode = 0;
+
+ if (device & KMX61_ACC) {
+ if (ret & KMX61_ACC_STBY_BIT)
+ *mode |= KMX61_ACC_STBY_BIT;
+ else
+ *mode &= ~KMX61_ACC_STBY_BIT;
+ }
+
+ if (device & KMX61_MAG) {
+ if (ret & KMX61_MAG_STBY_BIT)
+ *mode |= KMX61_MAG_STBY_BIT;
+ else
+ *mode &= ~KMX61_MAG_STBY_BIT;
+ }
+
+ return 0;
+}
+
+static int kmx61_set_odr(struct kmx61_data *data, int val, int val2, u8 device)
+{
+ int ret;
+ u8 mode;
+ int lodr_bits, odr_bits;
+
+ ret = kmx61_get_mode(data, &mode, KMX61_ACC | KMX61_MAG);
+ if (ret < 0)
+ return ret;
+
+ lodr_bits = kmx61_convert_freq_to_bit(val, val2);
+ if (lodr_bits < 0)
+ return lodr_bits;
+
+ /* To change ODR, accel and magn must be in STDBY */
+ ret = kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG);
+ if (ret < 0)
+ return ret;
+
+ odr_bits = 0;
+ if (device & KMX61_ACC)
+ odr_bits |= lodr_bits;
+ if (device & KMX61_MAG)
+ odr_bits |= (lodr_bits << KMX61_MAG_ODR_SHIFT);
+
+ ret = i2c_smbus_write_byte_data(data->client, KMX61_REG_ODCNTL,
+ odr_bits);
+ if (ret < 0)
+ return ret;
+
+ ret = kmx61_set_mode(data, mode, KMX61_ACC | KMX61_MAG);
+ if (ret < 0)
+ return ret;
+
+ data->odr_bits = lodr_bits;
+
+ return 0;
+}
+
+static
+int kmx61_get_odr(struct kmx61_data *data, int *val, int *val2, u8 device)
+{ int i;
+ u8 lodr_bits;
+
+ if (device & KMX61_ACC)
+ lodr_bits = (data->odr_bits >> KMX61_ACC_ODR_SHIFT) &
+ KMX61_ACC_ODR_MASK;
+ else if (device & KMX61_MAG)
+ lodr_bits = (data->odr_bits >> KMX61_MAG_ODR_SHIFT) &
+ KMX61_MAG_ODR_MASK;
+ else
+ return -EINVAL;
+
+ for (i = 0; i < ARRAY_SIZE(samp_freq_table); i++)
+ if (lodr_bits == samp_freq_table[i].odr_bits) {
+ *val = samp_freq_table[i].val;
+ *val2 = samp_freq_table[i].val2;
+ return 0;
+ }
+ return -EINVAL;
+}
+
+static int kmx61_set_range(struct kmx61_data *data, int range)
+{
+ int ret;
+
+ ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_CTRL1);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "Error reading reg_ctrl1\n");
+ return ret;
+ }
+
+ ret &= ~(KMX61_REG_CTRL1_GSEL0_MASK | KMX61_REG_CTRL1_GSEL1_MASK);
+ ret |= kmx61_scale_table[range].gsel0 << KMX61_REG_CTRL1_GSEL0_SHIFT;
+ ret |= kmx61_scale_table[range].gsel1 << KMX61_REG_CTRL1_GSEL1_SHIFT;
+
+ ret = i2c_smbus_write_byte_data(data->client, KMX61_REG_CTRL1, ret);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "Error writing reg_ctrl1\n");
+ return ret;
+ }
+
+ data->range = range;
+
+ return 0;
+}
+
+static int kmx61_set_scale(struct kmx61_data *data, int val)
+{
+ int ret, i;
+ u8 mode;
+
+ for (i = 0; i < ARRAY_SIZE(kmx61_scale_table); i++) {
+ if (kmx61_scale_table[i].scale == val) {
+ ret = kmx61_get_mode(data, &mode,
+ KMX61_ACC | KMX61_MAG);
+ if (ret < 0)
+ return ret;
+
+ ret = kmx61_set_mode(data, KMX61_ALL_STBY,
+ KMX61_ACC | KMX61_MAG);
+ if (ret < 0)
+ return ret;
+
+ ret = kmx61_set_range(data, i);
+ if (ret < 0)
+ return ret;
+
+ ret = kmx61_set_mode(data, mode,
+ KMX61_ACC | KMX61_MAG);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+ }
+ }
+ return -EINVAL;
+}
+
+static int kmx61_chip_init(struct kmx61_data *data)
+{
+ int ret;
+
+ ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_WHO_AM_I);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "Error reading who_am_i\n");
+ return ret;
+ }
+
+ if (ret != KMX61_CHIP_ID) {
+ dev_err(&data->client->dev,
+ "Wrong chip id, got %x expected %x\n",
+ ret, KMX61_CHIP_ID);
+ return -EINVAL;
+ }
+
+ /* set accel 12bit, 4g range */
+ ret = kmx61_set_range(data, KMX61_RANGE_4G);
+ if (ret < 0)
+ return ret;
+
+ /* put accel and magnetometer in operating mode */
+ ret = kmx61_set_mode(data, 0, KMX61_ACC | KMX61_MAG);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static int kmx61_read_measurement(struct kmx61_data *data, int base, int offset)
+{
+ int ret;
+ u8 reg = base + offset * 2;
+
+ ret = i2c_smbus_read_word_data(data->client, reg);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "failed to read reg at %x\n", reg);
+ return ret;
+ }
+
+ return ret;
+}
+
+static int kmx61_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ struct kmx61_data *data = iio_priv(indio_dev);
+ int ret;
+ u8 base_reg;
+ u8 device;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ switch (chan->type) {
+ case IIO_ACCEL: case IIO_MAGN:
+ base_reg = KMX61_ACC_XOUT_L;
+ break;
+ default:
+ return -EINVAL;
+ }
+ ret = kmx61_read_measurement(data, base_reg, chan->scan_index);
+ if (ret < 0)
+ return ret;
+ *val = sign_extend32(ret >> chan->scan_type.shift,
+ chan->scan_type.realbits - 1);
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->type) {
+ case IIO_ACCEL:
+ *val = 0;
+ *val2 = kmx61_scale_table[data->range].scale;
+ return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_MAGN:
+ /* 14 bits res, 1465 microGauss per magn count */
+ *val = 0;
+ *val2 = 1465;
+ return IIO_VAL_INT_PLUS_MICRO;
+ default:
+ break;
+ }
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ switch (chan->type) {
+ case IIO_ACCEL:
+ device = KMX61_ACC;
+ break;
+ case IIO_MAGN:
+ device = KMX61_MAG;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ mutex_lock(&data->lock);
+ ret = kmx61_get_odr(data, val, val2, device);
+ mutex_unlock(&data->lock);
+ if (ret)
+ return -EINVAL;
+ return IIO_VAL_INT_PLUS_MICRO;
+ }
+ return -EINVAL;
+}
+
+static int kmx61_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int val,
+ int val2, long mask)
+{
+ struct kmx61_data *data = iio_priv(indio_dev);
+ int ret;
+ u8 device;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ switch (chan->type) {
+ case IIO_ACCEL:
+ device = KMX61_ACC;
+ break;
+ case IIO_MAGN:
+ device = KMX61_MAG;
+ break;
+ default:
+ return -EINVAL;
+ }
+ mutex_lock(&data->lock);
+ ret = kmx61_set_odr(data, val, val2, device);
+ mutex_unlock(&data->lock);
+ break;
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->type) {
+ case IIO_ACCEL:
+ mutex_lock(&data->lock);
+ ret = kmx61_set_scale(data, val2);
+ mutex_unlock(&data->lock);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
+static const struct iio_info kmx61_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = kmx61_read_raw,
+ .write_raw = kmx61_write_raw,
+ .attrs = &kmx61_attribute_group,
+};
+
+static int kmx61_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct kmx61_data *data;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ data = iio_priv(indio_dev);
+ i2c_set_clientdata(client, indio_dev);
+ data->client = client;
+
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->info = &kmx61_info;
+ indio_dev->channels = kmx61_channels;
+ indio_dev->num_channels = ARRAY_SIZE(kmx61_channels);
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ mutex_init(&data->lock);
+
+ ret = kmx61_chip_init(data);
+ if (ret < 0)
+ return ret;
+
+ return iio_device_register(indio_dev);
+}
+
+static int kmx61_remove(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct kmx61_data *data = iio_priv(indio_dev);
+ int ret;
+
+ iio_device_unregister(indio_dev);
+
+ mutex_lock(&data->lock);
+ ret = kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG);
+ mutex_unlock(&data->lock);
+
+ return ret;
+}
+
+static const struct i2c_device_id kmx61_id[] = {
+ {"kmx61", 0},
+ {}
+};
+
+MODULE_DEVICE_TABLE(i2c, kmx61_id);
+
+static struct i2c_driver kmx61_driver = {
+ .driver = {
+ .name = "kmx61",
+ },
+ .probe = kmx61_probe,
+ .remove = kmx61_remove,
+ .id_table = kmx61_id,
+};
+
+module_i2c_driver(kmx61_driver);
+
+MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");
+MODULE_DESCRIPTION("KMX61 accelerometer/magnetometer driver");
+MODULE_LICENSE("GPL v2");
--
1.9.1


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