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");