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