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path: root/drivers/iio/accel/kxsd9.c
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Diffstat (limited to 'drivers/iio/accel/kxsd9.c')
-rw-r--r--drivers/iio/accel/kxsd9.c287
1 files changed, 287 insertions, 0 deletions
diff --git a/drivers/iio/accel/kxsd9.c b/drivers/iio/accel/kxsd9.c
new file mode 100644
index 000000000000..c2229a521ab9
--- /dev/null
+++ b/drivers/iio/accel/kxsd9.c
@@ -0,0 +1,287 @@
+/*
+ * kxsd9.c simple support for the Kionix KXSD9 3D
+ * accelerometer.
+ *
+ * Copyright (c) 2008-2009 Jonathan Cameron <jic23@kernel.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * The i2c interface is very similar, so shouldn't be a problem once
+ * I have a suitable wire made up.
+ *
+ * TODO: Support the motion detector
+ * Uses register address incrementing so could have a
+ * heavily optimized ring buffer access function.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/spi/spi.h>
+#include <linux/sysfs.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define KXSD9_REG_X 0x00
+#define KXSD9_REG_Y 0x02
+#define KXSD9_REG_Z 0x04
+#define KXSD9_REG_AUX 0x06
+#define KXSD9_REG_RESET 0x0a
+#define KXSD9_REG_CTRL_C 0x0c
+
+#define KXSD9_FS_MASK 0x03
+
+#define KXSD9_REG_CTRL_B 0x0d
+#define KXSD9_REG_CTRL_A 0x0e
+
+#define KXSD9_READ(a) (0x80 | (a))
+#define KXSD9_WRITE(a) (a)
+
+#define KXSD9_STATE_RX_SIZE 2
+#define KXSD9_STATE_TX_SIZE 2
+/**
+ * struct kxsd9_state - device related storage
+ * @buf_lock: protect the rx and tx buffers.
+ * @us: spi device
+ * @rx: single rx buffer storage
+ * @tx: single tx buffer storage
+ **/
+struct kxsd9_state {
+ struct mutex buf_lock;
+ struct spi_device *us;
+ u8 rx[KXSD9_STATE_RX_SIZE] ____cacheline_aligned;
+ u8 tx[KXSD9_STATE_TX_SIZE];
+};
+
+#define KXSD9_SCALE_2G "0.011978"
+#define KXSD9_SCALE_4G "0.023927"
+#define KXSD9_SCALE_6G "0.035934"
+#define KXSD9_SCALE_8G "0.047853"
+
+/* reverse order */
+static const int kxsd9_micro_scales[4] = { 47853, 35934, 23927, 11978 };
+
+static int kxsd9_write_scale(struct iio_dev *indio_dev, int micro)
+{
+ int ret, i;
+ struct kxsd9_state *st = iio_priv(indio_dev);
+ bool foundit = false;
+
+ for (i = 0; i < 4; i++)
+ if (micro == kxsd9_micro_scales[i]) {
+ foundit = true;
+ break;
+ }
+ if (!foundit)
+ return -EINVAL;
+
+ mutex_lock(&st->buf_lock);
+ ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));
+ if (ret)
+ goto error_ret;
+ st->tx[0] = KXSD9_WRITE(KXSD9_REG_CTRL_C);
+ st->tx[1] = (ret & ~KXSD9_FS_MASK) | i;
+
+ ret = spi_write(st->us, st->tx, 2);
+error_ret:
+ mutex_unlock(&st->buf_lock);
+ return ret;
+}
+
+static int kxsd9_read(struct iio_dev *indio_dev, u8 address)
+{
+ int ret;
+ struct kxsd9_state *st = iio_priv(indio_dev);
+ struct spi_transfer xfers[] = {
+ {
+ .bits_per_word = 8,
+ .len = 1,
+ .delay_usecs = 200,
+ .tx_buf = st->tx,
+ }, {
+ .bits_per_word = 8,
+ .len = 2,
+ .rx_buf = st->rx,
+ },
+ };
+
+ mutex_lock(&st->buf_lock);
+ st->tx[0] = KXSD9_READ(address);
+ ret = spi_sync_transfer(st->us, xfers, ARRAY_SIZE(xfers));
+ if (ret)
+ return ret;
+ return (((u16)(st->rx[0])) << 8) | (st->rx[1] & 0xF0);
+}
+
+static IIO_CONST_ATTR(accel_scale_available,
+ KXSD9_SCALE_2G " "
+ KXSD9_SCALE_4G " "
+ KXSD9_SCALE_6G " "
+ KXSD9_SCALE_8G);
+
+static struct attribute *kxsd9_attributes[] = {
+ &iio_const_attr_accel_scale_available.dev_attr.attr,
+ NULL,
+};
+
+static int kxsd9_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val,
+ int val2,
+ long mask)
+{
+ int ret = -EINVAL;
+
+ if (mask == IIO_CHAN_INFO_SCALE) {
+ /* Check no integer component */
+ if (val)
+ return -EINVAL;
+ ret = kxsd9_write_scale(indio_dev, val2);
+ }
+
+ return ret;
+}
+
+static int kxsd9_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ int ret = -EINVAL;
+ struct kxsd9_state *st = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = kxsd9_read(indio_dev, chan->address);
+ if (ret < 0)
+ goto error_ret;
+ *val = ret;
+ break;
+ case IIO_CHAN_INFO_SCALE:
+ ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));
+ if (ret)
+ goto error_ret;
+ *val2 = kxsd9_micro_scales[ret & KXSD9_FS_MASK];
+ ret = IIO_VAL_INT_PLUS_MICRO;
+ break;
+ }
+
+error_ret:
+ return ret;
+};
+#define KXSD9_ACCEL_CHAN(axis) \
+ { \
+ .type = IIO_ACCEL, \
+ .modified = 1, \
+ .channel2 = IIO_MOD_##axis, \
+ .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \
+ IIO_CHAN_INFO_SCALE_SHARED_BIT, \
+ .address = KXSD9_REG_##axis, \
+ }
+
+static const struct iio_chan_spec kxsd9_channels[] = {
+ KXSD9_ACCEL_CHAN(X), KXSD9_ACCEL_CHAN(Y), KXSD9_ACCEL_CHAN(Z),
+ {
+ .type = IIO_VOLTAGE,
+ .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT,
+ .indexed = 1,
+ .address = KXSD9_REG_AUX,
+ }
+};
+
+static const struct attribute_group kxsd9_attribute_group = {
+ .attrs = kxsd9_attributes,
+};
+
+static int kxsd9_power_up(struct kxsd9_state *st)
+{
+ int ret;
+
+ st->tx[0] = 0x0d;
+ st->tx[1] = 0x40;
+ ret = spi_write(st->us, st->tx, 2);
+ if (ret)
+ return ret;
+
+ st->tx[0] = 0x0c;
+ st->tx[1] = 0x9b;
+ return spi_write(st->us, st->tx, 2);
+};
+
+static const struct iio_info kxsd9_info = {
+ .read_raw = &kxsd9_read_raw,
+ .write_raw = &kxsd9_write_raw,
+ .attrs = &kxsd9_attribute_group,
+ .driver_module = THIS_MODULE,
+};
+
+static int kxsd9_probe(struct spi_device *spi)
+{
+ struct iio_dev *indio_dev;
+ struct kxsd9_state *st;
+ int ret;
+
+ indio_dev = iio_device_alloc(sizeof(*st));
+ if (indio_dev == NULL) {
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+ st = iio_priv(indio_dev);
+ spi_set_drvdata(spi, indio_dev);
+
+ st->us = spi;
+ mutex_init(&st->buf_lock);
+ indio_dev->channels = kxsd9_channels;
+ indio_dev->num_channels = ARRAY_SIZE(kxsd9_channels);
+ indio_dev->name = spi_get_device_id(spi)->name;
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->info = &kxsd9_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ spi->mode = SPI_MODE_0;
+ spi_setup(spi);
+ kxsd9_power_up(st);
+
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ goto error_free_dev;
+
+ return 0;
+
+error_free_dev:
+ iio_device_free(indio_dev);
+error_ret:
+ return ret;
+}
+
+static int kxsd9_remove(struct spi_device *spi)
+{
+ iio_device_unregister(spi_get_drvdata(spi));
+ iio_device_free(spi_get_drvdata(spi));
+
+ return 0;
+}
+
+static const struct spi_device_id kxsd9_id[] = {
+ {"kxsd9", 0},
+ { },
+};
+MODULE_DEVICE_TABLE(spi, kxsd9_id);
+
+static struct spi_driver kxsd9_driver = {
+ .driver = {
+ .name = "kxsd9",
+ .owner = THIS_MODULE,
+ },
+ .probe = kxsd9_probe,
+ .remove = kxsd9_remove,
+ .id_table = kxsd9_id,
+};
+module_spi_driver(kxsd9_driver);
+
+MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
+MODULE_DESCRIPTION("Kionix KXSD9 SPI driver");
+MODULE_LICENSE("GPL v2");