--- /dev/null
+/*
+ * 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).
+ *
+ */
+
+#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
+
+/*
+ * three 16-bit accelerometer output registers for X/Y/Z axis
+ * we use only XOUT_L as a base register, all other addresses
+ * can be obtained by applying an offset and are provided here
+ * only for clarity.
+ */
+#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
+
+/*
+ * one 16-bit temperature output register
+ */
+#define KMX61_TEMP_L 0x10
+#define KMX61_TEMP_H 0x11
+
+/*
+ * three 16-bit magnetometer output registers for X/Y/Z axis
+ */
+#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_STBY 0x29
+#define KMX61_REG_CTRL1 0x2A
+#define KMX61_REG_ODCNTL 0x2C
+
+#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_GSEL_MASK 0x03
+
+#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
+
+/* KMX61 devices */
+#define KMX61_ACC 0x01
+#define KMX61_MAG 0x02
+
+struct kmx61_data {
+ struct i2c_client *client;
+
+ /* serialize access to non-atomic ops, e.g set_mode */
+ struct mutex lock;
+
+ /* standby state */
+ bool acc_stby;
+ bool mag_stby;
+
+ /* config bits */
+ u8 range;
+ u8 odr_bits;
+
+ /* accelerometer specific data */
+ struct iio_dev *acc_indio_dev;
+
+ /* magnetometer specific data */
+ struct iio_dev *mag_indio_dev;
+};
+
+enum kmx61_range {
+ KMX61_RANGE_2G,
+ KMX61_RANGE_4G,
+ KMX61_RANGE_8G,
+};
+
+enum kmx61_axis {
+ KMX61_AXIS_X,
+ KMX61_AXIS_Y,
+ KMX61_AXIS_Z,
+};
+
+static const u16 kmx61_uscale_table[] = {9582, 19163, 38326};
+
+static const struct {
+ int val;
+ int val2;
+ u8 odr_bits;
+} kmx61_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_acc_attributes[] = {
+ &iio_const_attr_accel_scale_available.dev_attr.attr,
+ &iio_const_attr_sampling_frequency_available.dev_attr.attr,
+ NULL,
+};
+
+static struct attribute *kmx61_mag_attributes[] = {
+ &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_acc_attribute_group = {
+ .attrs = kmx61_acc_attributes,
+};
+
+static const struct attribute_group kmx61_mag_attribute_group = {
+ .attrs = kmx61_mag_attributes,
+};
+
+#define KMX61_ACC_CHAN(_axis) { \
+ .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), \
+ .address = KMX61_ACC, \
+ .scan_index = KMX61_AXIS_ ## _axis, \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 12, \
+ .storagebits = 16, \
+ .shift = 4, \
+ .endianness = IIO_LE, \
+ }, \
+}
+
+#define KMX61_MAG_CHAN(_axis) { \
+ .type = IIO_MAGN, \
+ .modified = 1, \
+ .channel2 = IIO_MOD_ ## _axis, \
+ .address = KMX61_MAG, \
+ .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 = KMX61_AXIS_ ## _axis, \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 14, \
+ .storagebits = 16, \
+ .shift = 2, \
+ .endianness = IIO_LE, \
+ }, \
+}
+
+static const struct iio_chan_spec kmx61_acc_channels[] = {
+ KMX61_ACC_CHAN(X),
+ KMX61_ACC_CHAN(Y),
+ KMX61_ACC_CHAN(Z),
+};
+
+static const struct iio_chan_spec kmx61_mag_channels[] = {
+ KMX61_MAG_CHAN(X),
+ KMX61_MAG_CHAN(Y),
+ KMX61_MAG_CHAN(Z),
+};
+
+static void kmx61_set_data(struct iio_dev *indio_dev, struct kmx61_data *data)
+{
+ struct kmx61_data **priv = iio_priv(indio_dev);
+
+ *priv = data;
+}
+
+static struct kmx61_data *kmx61_get_data(struct iio_dev *indio_dev)
+{
+ return *(struct kmx61_data **)iio_priv(indio_dev);
+}
+
+static int kmx61_convert_freq_to_bit(int val, int val2)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(kmx61_samp_freq_table); i++)
+ if (val == kmx61_samp_freq_table[i].val &&
+ val2 == kmx61_samp_freq_table[i].val2)
+ return kmx61_samp_freq_table[i].odr_bits;
+ return -EINVAL;
+}
+
+/**
+ * kmx61_set_mode() - set KMX61 device operating mode
+ * @data - kmx61 device private data pointer
+ * @mode - bitmask, indicating operating mode for @device
+ * @device - bitmask, indicating device for which @mode needs to be set
+ * @update - update stby bits stored in device's private @data
+ *
+ * For each sensor (accelerometer/magnetometer) there are two operating modes
+ * STANDBY and OPERATION. Neither accel nor magn can be disabled independently
+ * if they are both enabled. Internal sensors state is saved in acc_stby and
+ * mag_stby members of driver's private @data.
+ */
+static int kmx61_set_mode(struct kmx61_data *data, u8 mode, u8 device,
+ bool update)
+{
+ int ret;
+ int acc_stby = -1, mag_stby = -1;
+
+ 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;
+ acc_stby = 1;
+ } else {
+ ret &= ~KMX61_ACC_STBY_BIT;
+ acc_stby = 0;
+ }
+ }
+
+ if (device & KMX61_MAG) {
+ if (mode & KMX61_MAG_STBY_BIT) {
+ ret |= KMX61_MAG_STBY_BIT;
+ mag_stby = 1;
+ } else {
+ ret &= ~KMX61_MAG_STBY_BIT;
+ mag_stby = 0;
+ }
+ }
+
+ if (mode & KMX61_ACT_STBY_BIT)
+ ret |= KMX61_ACT_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;
+ }
+
+ if (acc_stby != -1 && update)
+ data->acc_stby = acc_stby;
+ if (mag_stby != -1 && update)
+ data->mag_stby = mag_stby;
+
+ return 0;
+}
+
+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,
+ true);
+ if (ret < 0)
+ return ret;
+
+ odr_bits = 0;
+ if (device & KMX61_ACC)
+ odr_bits |= lodr_bits << KMX61_ACC_ODR_SHIFT;
+ 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;
+
+ return kmx61_set_mode(data, mode, KMX61_ACC | KMX61_MAG, true);
+}
+
+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(kmx61_samp_freq_table); i++)
+ if (lodr_bits == kmx61_samp_freq_table[i].odr_bits) {
+ *val = kmx61_samp_freq_table[i].val;
+ *val2 = kmx61_samp_freq_table[i].val2;
+ return 0;
+ }
+ return -EINVAL;
+}
+
+static int kmx61_set_range(struct kmx61_data *data, u8 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_GSEL_MASK;
+ ret |= range & KMX61_REG_CTRL1_GSEL_MASK;
+
+ 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, u16 uscale)
+{
+ int ret, i;
+ u8 mode;
+
+ for (i = 0; i < ARRAY_SIZE(kmx61_uscale_table); i++) {
+ if (kmx61_uscale_table[i] == uscale) {
+ 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, true);
+ if (ret < 0)
+ return ret;
+
+ ret = kmx61_set_range(data, i);
+ if (ret < 0)
+ return ret;
+
+ return kmx61_set_mode(data, mode,
+ KMX61_ACC | KMX61_MAG, true);
+ }
+ }
+ 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;
+
+ ret = i2c_smbus_read_byte_data(data->client, KMX61_REG_ODCNTL);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "Error reading reg_odcntl\n");
+ return ret;
+ }
+ data->odr_bits = ret;
+
+ /* set acc/magn to OPERATION mode */
+ ret = kmx61_set_mode(data, 0, KMX61_ACC | KMX61_MAG, true);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static int kmx61_read_measurement(struct kmx61_data *data, u8 base, u8 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;
+}
+
+static int kmx61_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ int ret;
+ u8 base_reg;
+ struct kmx61_data *data = kmx61_get_data(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ switch (chan->type) {
+ case IIO_ACCEL:
+ base_reg = KMX61_ACC_XOUT_L;
+ break;
+ case IIO_MAGN:
+ base_reg = KMX61_MAG_XOUT_L;
+ break;
+ default:
+ return -EINVAL;
+ }
+ mutex_lock(&data->lock);
+
+ ret = kmx61_read_measurement(data, base_reg, chan->scan_index);
+ if (ret < 0) {
+ mutex_unlock(&data->lock);
+ return ret;
+ }
+ *val = sign_extend32(ret >> chan->scan_type.shift,
+ chan->scan_type.realbits - 1);
+
+ mutex_unlock(&data->lock);
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->type) {
+ case IIO_ACCEL:
+ *val = 0;
+ *val2 = kmx61_uscale_table[data->range];
+ 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:
+ return -EINVAL;
+ }
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ if (chan->type != IIO_ACCEL && chan->type != IIO_MAGN)
+ return -EINVAL;
+
+ mutex_lock(&data->lock);
+ ret = kmx61_get_odr(data, val, val2, chan->address);
+ 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)
+{
+ int ret;
+ struct kmx61_data *data = kmx61_get_data(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ if (chan->type != IIO_ACCEL && chan->type != IIO_MAGN)
+ return -EINVAL;
+
+ mutex_lock(&data->lock);
+ ret = kmx61_set_odr(data, val, val2, chan->address);
+ mutex_unlock(&data->lock);
+ return ret;
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->type) {
+ case IIO_ACCEL:
+ if (val != 0)
+ return -EINVAL;
+ mutex_lock(&data->lock);
+ ret = kmx61_set_scale(data, val2);
+ mutex_unlock(&data->lock);
+ return ret;
+ default:
+ return -EINVAL;
+ }
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info kmx61_acc_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = kmx61_read_raw,
+ .write_raw = kmx61_write_raw,
+ .attrs = &kmx61_acc_attribute_group,
+};
+
+static const struct iio_info kmx61_mag_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = kmx61_read_raw,
+ .write_raw = kmx61_write_raw,
+ .attrs = &kmx61_mag_attribute_group,
+};
+
+static struct iio_dev *kmx61_indiodev_setup(struct kmx61_data *data,
+ const struct iio_info *info,
+ const struct iio_chan_spec *chan,
+ int num_channels,
+ const char *name)
+{
+ struct iio_dev *indio_dev;
+
+ indio_dev = devm_iio_device_alloc(&data->client->dev, sizeof(data));
+ if (!indio_dev)
+ return ERR_PTR(-ENOMEM);
+
+ kmx61_set_data(indio_dev, data);
+
+ indio_dev->dev.parent = &data->client->dev;
+ indio_dev->channels = chan;
+ indio_dev->num_channels = num_channels;
+ indio_dev->name = name;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = info;
+
+ return indio_dev;
+}
+
+static int kmx61_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ int ret;
+ struct kmx61_data *data;
+ const char *name = NULL;
+
+ data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, data);
+ data->client = client;
+
+ mutex_init(&data->lock);
+
+ data->acc_indio_dev =
+ kmx61_indiodev_setup(data, &kmx61_acc_info,
+ kmx61_acc_channels,
+ ARRAY_SIZE(kmx61_acc_channels),
+ name);
+ if (IS_ERR(data->acc_indio_dev))
+ return PTR_ERR(data->acc_indio_dev);
+
+ data->mag_indio_dev =
+ kmx61_indiodev_setup(data, &kmx61_mag_info,
+ kmx61_mag_channels,
+ ARRAY_SIZE(kmx61_mag_channels),
+ name);
+ if (IS_ERR(data->mag_indio_dev))
+ return PTR_ERR(data->mag_indio_dev);
+
+ ret = kmx61_chip_init(data);
+ if (ret < 0)
+ return ret;
+
+ ret = iio_device_register(data->acc_indio_dev);
+ if (ret < 0) {
+ dev_err(&client->dev, "Failed to register acc iio device\n");
+ goto err_chip_uninit;
+ }
+
+ ret = iio_device_register(data->mag_indio_dev);
+ if (ret < 0) {
+ dev_err(&client->dev, "Failed to register mag iio device\n");
+ goto err_iio_unregister;
+ }
+
+ return 0;
+
+err_iio_unregister:
+ iio_device_unregister(data->acc_indio_dev);
+err_chip_uninit:
+ kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG, true);
+ return ret;
+}
+
+static int kmx61_remove(struct i2c_client *client)
+{
+ struct kmx61_data *data = i2c_get_clientdata(client);
+
+ iio_device_unregister(data->acc_indio_dev);
+ iio_device_unregister(data->mag_indio_dev);
+
+ mutex_lock(&data->lock);
+ kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG, true);
+ mutex_unlock(&data->lock);
+
+ return 0;
+}
+
+static const struct i2c_device_id kmx61_id[] = {
+ {"kmx611021", 0},
+ {}
+};
+
+MODULE_DEVICE_TABLE(i2c, kmx61_id);
+
+static struct i2c_driver kmx61_driver = {
+ .driver = {
+ .name = KMX61_DRV_NAME,
+ },
+ .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");