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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>
25
26#include "../iio.h"
27#include "../sysfs.h"
28
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
35
36#define KXSD9_FS_MASK 0x03
37
38#define KXSD9_REG_CTRL_B 0x0d
39#define KXSD9_REG_CTRL_A 0x0e
40
41#define KXSD9_READ(a) (0x80 | (a))
42#define KXSD9_WRITE(a) (a)
43
44#define KXSD9_STATE_RX_SIZE 2
45#define KXSD9_STATE_TX_SIZE 2
46
47
48
49
50
51
52
53struct kxsd9_state {
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];
58};
59
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"
64
65
66static const int kxsd9_micro_scales[4] = { 47853, 35934, 23927, 11978 };
67
68static int kxsd9_write_scale(struct iio_dev *indio_dev, int micro)
69{
70 int ret, i;
71 struct kxsd9_state *st = iio_priv(indio_dev);
72 bool foundit = false;
73
74 for (i = 0; i < 4; i++)
75 if (micro == kxsd9_micro_scales[i]) {
76 foundit = true;
77 break;
78 }
79 if (!foundit)
80 return -EINVAL;
81
82 mutex_lock(&st->buf_lock);
83 ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));
84 if (ret)
85 goto error_ret;
86 st->tx[0] = KXSD9_WRITE(KXSD9_REG_CTRL_C);
87 st->tx[1] = (ret & ~KXSD9_FS_MASK) | i;
88
89 ret = spi_write(st->us, st->tx, 2);
90error_ret:
91 mutex_unlock(&st->buf_lock);
92 return ret;
93}
94
95static int kxsd9_read(struct iio_dev *indio_dev, u8 address)
96{
97 struct spi_message msg;
98 int ret;
99 struct kxsd9_state *st = iio_priv(indio_dev);
100 struct spi_transfer xfers[] = {
101 {
102 .bits_per_word = 8,
103 .len = 1,
104 .delay_usecs = 200,
105 .tx_buf = st->tx,
106 }, {
107 .bits_per_word = 8,
108 .len = 2,
109 .rx_buf = st->rx,
110 },
111 };
112
113 mutex_lock(&st->buf_lock);
114 st->tx[0] = KXSD9_READ(address);
115 spi_message_init(&msg);
116 spi_message_add_tail(&xfers[0], &msg);
117 spi_message_add_tail(&xfers[1], &msg);
118 ret = spi_sync(st->us, &msg);
119 if (ret)
120 return ret;
121 return (((u16)(st->rx[0])) << 8) | (st->rx[1] & 0xF0);
122}
123
124static IIO_CONST_ATTR(accel_scale_available,
125 KXSD9_SCALE_2G " "
126 KXSD9_SCALE_4G " "
127 KXSD9_SCALE_6G " "
128 KXSD9_SCALE_8G);
129
130static struct attribute *kxsd9_attributes[] = {
131 &iio_const_attr_accel_scale_available.dev_attr.attr,
132 NULL,
133};
134
135static int kxsd9_write_raw(struct iio_dev *indio_dev,
136 struct iio_chan_spec const *chan,
137 int val,
138 int val2,
139 long mask)
140{
141 int ret = -EINVAL;
142
143 if (mask == IIO_CHAN_INFO_SCALE) {
144
145 if (val)
146 return -EINVAL;
147 ret = kxsd9_write_scale(indio_dev, val2);
148 }
149
150 return ret;
151}
152
153static int kxsd9_read_raw(struct iio_dev *indio_dev,
154 struct iio_chan_spec const *chan,
155 int *val, int *val2, long mask)
156{
157 int ret = -EINVAL;
158 struct kxsd9_state *st = iio_priv(indio_dev);
159
160 switch (mask) {
161 case 0:
162 ret = kxsd9_read(indio_dev, chan->address);
163 if (ret < 0)
164 goto error_ret;
165 *val = ret;
166 break;
167 case IIO_CHAN_INFO_SCALE:
168 ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));
169 if (ret)
170 goto error_ret;
171 *val2 = kxsd9_micro_scales[ret & KXSD9_FS_MASK];
172 ret = IIO_VAL_INT_PLUS_MICRO;
173 break;
174 };
175
176error_ret:
177 return ret;
178};
179#define KXSD9_ACCEL_CHAN(axis) \
180 { \
181 .type = IIO_ACCEL, \
182 .modified = 1, \
183 .channel2 = IIO_MOD_##axis, \
184 .info_mask = IIO_CHAN_INFO_SCALE_SHARED_BIT, \
185 .address = KXSD9_REG_##axis, \
186 }
187
188static struct iio_chan_spec kxsd9_channels[] = {
189 KXSD9_ACCEL_CHAN(X), KXSD9_ACCEL_CHAN(Y), KXSD9_ACCEL_CHAN(Z),
190 {
191 .type = IIO_VOLTAGE,
192 .indexed = 1,
193 .address = KXSD9_REG_AUX,
194 }
195};
196
197static const struct attribute_group kxsd9_attribute_group = {
198 .attrs = kxsd9_attributes,
199};
200
201static int __devinit kxsd9_power_up(struct kxsd9_state *st)
202{
203 int ret;
204
205 st->tx[0] = 0x0d;
206 st->tx[1] = 0x40;
207 ret = spi_write(st->us, st->tx, 2);
208 if (ret)
209 return ret;
210
211 st->tx[0] = 0x0c;
212 st->tx[1] = 0x9b;
213 return spi_write(st->us, st->tx, 2);
214};
215
216static const struct iio_info kxsd9_info = {
217 .read_raw = &kxsd9_read_raw,
218 .write_raw = &kxsd9_write_raw,
219 .attrs = &kxsd9_attribute_group,
220 .driver_module = THIS_MODULE,
221};
222
223static int __devinit kxsd9_probe(struct spi_device *spi)
224{
225 struct iio_dev *indio_dev;
226 struct kxsd9_state *st;
227 int ret = 0;
228
229 indio_dev = iio_allocate_device(sizeof(*st));
230 if (indio_dev == NULL) {
231 ret = -ENOMEM;
232 goto error_ret;
233 }
234 st = iio_priv(indio_dev);
235 spi_set_drvdata(spi, indio_dev);
236
237 st->us = spi;
238 mutex_init(&st->buf_lock);
239 indio_dev->channels = kxsd9_channels;
240 indio_dev->num_channels = ARRAY_SIZE(kxsd9_channels);
241 indio_dev->name = spi_get_device_id(spi)->name;
242 indio_dev->dev.parent = &spi->dev;
243 indio_dev->info = &kxsd9_info;
244 indio_dev->modes = INDIO_DIRECT_MODE;
245
246 ret = iio_device_register(indio_dev);
247 if (ret)
248 goto error_free_dev;
249
250 spi->mode = SPI_MODE_0;
251 spi_setup(spi);
252 kxsd9_power_up(st);
253
254 return 0;
255
256error_free_dev:
257 iio_free_device(indio_dev);
258error_ret:
259 return ret;
260}
261
262static int __devexit kxsd9_remove(struct spi_device *spi)
263{
264 iio_device_unregister(spi_get_drvdata(spi));
265 iio_free_device(spi_get_drvdata(spi));
266
267 return 0;
268}
269
270static const struct spi_device_id kxsd9_id[] = {
271 {"kxsd9", 0},
272 { },
273};
274MODULE_DEVICE_TABLE(spi, kxsd9_id);
275
276static struct spi_driver kxsd9_driver = {
277 .driver = {
278 .name = "kxsd9",
279 .owner = THIS_MODULE,
280 },
281 .probe = kxsd9_probe,
282 .remove = __devexit_p(kxsd9_remove),
283 .id_table = kxsd9_id,
284};
285module_spi_driver(kxsd9_driver);
286
287MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
288MODULE_DESCRIPTION("Kionix KXSD9 SPI driver");
289MODULE_LICENSE("GPL v2");
290
