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