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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 <linux/iio/iio.h>
27#include <linux/iio/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 int ret;
98 struct kxsd9_state *st = iio_priv(indio_dev);
99 struct spi_transfer xfers[] = {
100 {
101 .bits_per_word = 8,
102 .len = 1,
103 .delay_usecs = 200,
104 .tx_buf = st->tx,
105 }, {
106 .bits_per_word = 8,
107 .len = 2,
108 .rx_buf = st->rx,
109 },
110 };
111
112 mutex_lock(&st->buf_lock);
113 st->tx[0] = KXSD9_READ(address);
114 ret = spi_sync_transfer(st->us, xfers, ARRAY_SIZE(xfers));
115 if (ret)
116 return ret;
117 return (((u16)(st->rx[0])) << 8) | (st->rx[1] & 0xF0);
118}
119
120static IIO_CONST_ATTR(accel_scale_available,
121 KXSD9_SCALE_2G " "
122 KXSD9_SCALE_4G " "
123 KXSD9_SCALE_6G " "
124 KXSD9_SCALE_8G);
125
126static struct attribute *kxsd9_attributes[] = {
127 &iio_const_attr_accel_scale_available.dev_attr.attr,
128 NULL,
129};
130
131static int kxsd9_write_raw(struct iio_dev *indio_dev,
132 struct iio_chan_spec const *chan,
133 int val,
134 int val2,
135 long mask)
136{
137 int ret = -EINVAL;
138
139 if (mask == IIO_CHAN_INFO_SCALE) {
140
141 if (val)
142 return -EINVAL;
143 ret = kxsd9_write_scale(indio_dev, val2);
144 }
145
146 return ret;
147}
148
149static int kxsd9_read_raw(struct iio_dev *indio_dev,
150 struct iio_chan_spec const *chan,
151 int *val, int *val2, long mask)
152{
153 int ret = -EINVAL;
154 struct kxsd9_state *st = iio_priv(indio_dev);
155
156 switch (mask) {
157 case IIO_CHAN_INFO_RAW:
158 ret = kxsd9_read(indio_dev, chan->address);
159 if (ret < 0)
160 goto error_ret;
161 *val = ret;
162 break;
163 case IIO_CHAN_INFO_SCALE:
164 ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));
165 if (ret)
166 goto error_ret;
167 *val2 = kxsd9_micro_scales[ret & KXSD9_FS_MASK];
168 ret = IIO_VAL_INT_PLUS_MICRO;
169 break;
170 }
171
172error_ret:
173 return ret;
174};
175#define KXSD9_ACCEL_CHAN(axis) \
176 { \
177 .type = IIO_ACCEL, \
178 .modified = 1, \
179 .channel2 = IIO_MOD_##axis, \
180 .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \
181 IIO_CHAN_INFO_SCALE_SHARED_BIT, \
182 .address = KXSD9_REG_##axis, \
183 }
184
185static const struct iio_chan_spec kxsd9_channels[] = {
186 KXSD9_ACCEL_CHAN(X), KXSD9_ACCEL_CHAN(Y), KXSD9_ACCEL_CHAN(Z),
187 {
188 .type = IIO_VOLTAGE,
189 .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT,
190 .indexed = 1,
191 .address = KXSD9_REG_AUX,
192 }
193};
194
195static const struct attribute_group kxsd9_attribute_group = {
196 .attrs = kxsd9_attributes,
197};
198
199static int kxsd9_power_up(struct kxsd9_state *st)
200{
201 int ret;
202
203 st->tx[0] = 0x0d;
204 st->tx[1] = 0x40;
205 ret = spi_write(st->us, st->tx, 2);
206 if (ret)
207 return ret;
208
209 st->tx[0] = 0x0c;
210 st->tx[1] = 0x9b;
211 return spi_write(st->us, st->tx, 2);
212};
213
214static const struct iio_info kxsd9_info = {
215 .read_raw = &kxsd9_read_raw,
216 .write_raw = &kxsd9_write_raw,
217 .attrs = &kxsd9_attribute_group,
218 .driver_module = THIS_MODULE,
219};
220
221static int kxsd9_probe(struct spi_device *spi)
222{
223 struct iio_dev *indio_dev;
224 struct kxsd9_state *st;
225 int ret;
226
227 indio_dev = iio_device_alloc(sizeof(*st));
228 if (indio_dev == NULL) {
229 ret = -ENOMEM;
230 goto error_ret;
231 }
232 st = iio_priv(indio_dev);
233 spi_set_drvdata(spi, indio_dev);
234
235 st->us = spi;
236 mutex_init(&st->buf_lock);
237 indio_dev->channels = kxsd9_channels;
238 indio_dev->num_channels = ARRAY_SIZE(kxsd9_channels);
239 indio_dev->name = spi_get_device_id(spi)->name;
240 indio_dev->dev.parent = &spi->dev;
241 indio_dev->info = &kxsd9_info;
242 indio_dev->modes = INDIO_DIRECT_MODE;
243
244 spi->mode = SPI_MODE_0;
245 spi_setup(spi);
246 kxsd9_power_up(st);
247
248 ret = iio_device_register(indio_dev);
249 if (ret)
250 goto error_free_dev;
251
252 return 0;
253
254error_free_dev:
255 iio_device_free(indio_dev);
256error_ret:
257 return ret;
258}
259
260static int kxsd9_remove(struct spi_device *spi)
261{
262 iio_device_unregister(spi_get_drvdata(spi));
263 iio_device_free(spi_get_drvdata(spi));
264
265 return 0;
266}
267
268static const struct spi_device_id kxsd9_id[] = {
269 {"kxsd9", 0},
270 { },
271};
272MODULE_DEVICE_TABLE(spi, kxsd9_id);
273
274static struct spi_driver kxsd9_driver = {
275 .driver = {
276 .name = "kxsd9",
277 .owner = THIS_MODULE,
278 },
279 .probe = kxsd9_probe,
280 .remove = kxsd9_remove,
281 .id_table = kxsd9_id,
282};
283module_spi_driver(kxsd9_driver);
284
285MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
286MODULE_DESCRIPTION("Kionix KXSD9 SPI driver");
287MODULE_LICENSE("GPL v2");
288
