2 * kxsd9.c simple support for the Kionix KXSD9 3D
5 * Copyright (c) 2008-2009 Jonathan Cameron <jic23@kernel.org>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 * The i2c interface is very similar, so shouldn't be a problem once
12 * I have a suitable wire made up.
14 * TODO: Support the motion detector
15 * Uses register address incrementing so could have a
16 * heavily optimized ring buffer access function.
19 #include <linux/device.h>
20 #include <linux/kernel.h>
21 #include <linux/spi/spi.h>
22 #include <linux/sysfs.h>
23 #include <linux/slab.h>
24 #include <linux/module.h>
26 #include <linux/iio/iio.h>
27 #include <linux/iio/sysfs.h>
29 #define KXSD9_REG_X 0x00
30 #define KXSD9_REG_Y 0x02
31 #define KXSD9_REG_Z 0x04
32 #define KXSD9_REG_AUX 0x06
33 #define KXSD9_REG_RESET 0x0a
34 #define KXSD9_REG_CTRL_C 0x0c
36 #define KXSD9_FS_MASK 0x03
38 #define KXSD9_REG_CTRL_B 0x0d
39 #define KXSD9_REG_CTRL_A 0x0e
41 #define KXSD9_READ(a) (0x80 | (a))
42 #define KXSD9_WRITE(a) (a)
44 #define KXSD9_STATE_RX_SIZE 2
45 #define KXSD9_STATE_TX_SIZE 2
47 * struct kxsd9_state - device related storage
48 * @buf_lock: protect the rx and tx buffers.
50 * @rx: single rx buffer storage
51 * @tx: single tx buffer storage
54 struct mutex buf_lock;
55 struct spi_device *us;
56 u8 rx[KXSD9_STATE_RX_SIZE] ____cacheline_aligned;
57 u8 tx[KXSD9_STATE_TX_SIZE];
60 #define KXSD9_SCALE_2G "0.011978"
61 #define KXSD9_SCALE_4G "0.023927"
62 #define KXSD9_SCALE_6G "0.035934"
63 #define KXSD9_SCALE_8G "0.047853"
66 static const int kxsd9_micro_scales[4] = { 47853, 35934, 23927, 11978 };
68 static int kxsd9_write_scale(struct iio_dev *indio_dev, int micro)
71 struct kxsd9_state *st = iio_priv(indio_dev);
74 for (i = 0; i < 4; i++)
75 if (micro == kxsd9_micro_scales[i]) {
82 mutex_lock(&st->buf_lock);
83 ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));
86 st->tx[0] = KXSD9_WRITE(KXSD9_REG_CTRL_C);
87 st->tx[1] = (ret & ~KXSD9_FS_MASK) | i;
89 ret = spi_write(st->us, st->tx, 2);
91 mutex_unlock(&st->buf_lock);
95 static int kxsd9_read(struct iio_dev *indio_dev, u8 address)
98 struct kxsd9_state *st = iio_priv(indio_dev);
99 struct spi_transfer xfers[] = {
112 mutex_lock(&st->buf_lock);
113 st->tx[0] = KXSD9_READ(address);
114 ret = spi_sync_transfer(st->us, xfers, ARRAY_SIZE(xfers));
116 ret = (((u16)(st->rx[0])) << 8) | (st->rx[1] & 0xF0);
117 mutex_unlock(&st->buf_lock);
121 static IIO_CONST_ATTR(accel_scale_available,
127 static struct attribute *kxsd9_attributes[] = {
128 &iio_const_attr_accel_scale_available.dev_attr.attr,
132 static int kxsd9_write_raw(struct iio_dev *indio_dev,
133 struct iio_chan_spec const *chan,
140 if (mask == IIO_CHAN_INFO_SCALE) {
141 /* Check no integer component */
144 ret = kxsd9_write_scale(indio_dev, val2);
150 static int kxsd9_read_raw(struct iio_dev *indio_dev,
151 struct iio_chan_spec const *chan,
152 int *val, int *val2, long mask)
155 struct kxsd9_state *st = iio_priv(indio_dev);
158 case IIO_CHAN_INFO_RAW:
159 ret = kxsd9_read(indio_dev, chan->address);
165 case IIO_CHAN_INFO_SCALE:
166 ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));
170 *val2 = kxsd9_micro_scales[ret & KXSD9_FS_MASK];
171 ret = IIO_VAL_INT_PLUS_MICRO;
178 #define KXSD9_ACCEL_CHAN(axis) \
182 .channel2 = IIO_MOD_##axis, \
183 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
184 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
185 .address = KXSD9_REG_##axis, \
188 static const struct iio_chan_spec kxsd9_channels[] = {
189 KXSD9_ACCEL_CHAN(X), KXSD9_ACCEL_CHAN(Y), KXSD9_ACCEL_CHAN(Z),
192 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
194 .address = KXSD9_REG_AUX,
198 static const struct attribute_group kxsd9_attribute_group = {
199 .attrs = kxsd9_attributes,
202 static int kxsd9_power_up(struct kxsd9_state *st)
208 ret = spi_write(st->us, st->tx, 2);
214 return spi_write(st->us, st->tx, 2);
217 static const struct iio_info kxsd9_info = {
218 .read_raw = &kxsd9_read_raw,
219 .write_raw = &kxsd9_write_raw,
220 .attrs = &kxsd9_attribute_group,
221 .driver_module = THIS_MODULE,
224 static int kxsd9_probe(struct spi_device *spi)
226 struct iio_dev *indio_dev;
227 struct kxsd9_state *st;
229 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
233 st = iio_priv(indio_dev);
234 spi_set_drvdata(spi, indio_dev);
237 mutex_init(&st->buf_lock);
238 indio_dev->channels = kxsd9_channels;
239 indio_dev->num_channels = ARRAY_SIZE(kxsd9_channels);
240 indio_dev->name = spi_get_device_id(spi)->name;
241 indio_dev->dev.parent = &spi->dev;
242 indio_dev->info = &kxsd9_info;
243 indio_dev->modes = INDIO_DIRECT_MODE;
245 spi->mode = SPI_MODE_0;
249 return iio_device_register(indio_dev);
252 static int kxsd9_remove(struct spi_device *spi)
254 iio_device_unregister(spi_get_drvdata(spi));
259 static const struct spi_device_id kxsd9_id[] = {
263 MODULE_DEVICE_TABLE(spi, kxsd9_id);
265 static struct spi_driver kxsd9_driver = {
269 .probe = kxsd9_probe,
270 .remove = kxsd9_remove,
271 .id_table = kxsd9_id,
273 module_spi_driver(kxsd9_driver);
275 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
276 MODULE_DESCRIPTION("Kionix KXSD9 SPI driver");
277 MODULE_LICENSE("GPL v2");