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Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/upstream-linus
[linux-btrfs-devel.git] / drivers / staging / iio / accel / kxsd9.c
blobc8a358a5df87ee22bd75e2ec913ed4864acfe4d9
1 /*
2 * kxsd9.c simple support for the Kionix KXSD9 3D
3 * accelerometer.
4 *
5 * Copyright (c) 2008-2009 Jonathan Cameron <jic23@cam.ac.uk>
6 *
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.
10 *
11 * The i2c interface is very similar, so shouldn't be a problem once
12 * I have a suitable wire made up.
13 *
14 * TODO: Support the motion detector
15 * Uses register address incrementing so could have a
16 * heavily optimized ring buffer access function.
17 */
18
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
25 #include "../iio.h"
26 #include "../sysfs.h"
27 #include "../adc/adc.h"
28 #include "accel.h"
29
30 #define KXSD9_REG_X 0x00
31 #define KXSD9_REG_Y 0x02
32 #define KXSD9_REG_Z 0x04
33 #define KXSD9_REG_AUX 0x06
34 #define KXSD9_REG_RESET 0x0a
35 #define KXSD9_REG_CTRL_C 0x0c
36
37 #define KXSD9_FS_8 0x00
38 #define KXSD9_FS_6 0x01
39 #define KXSD9_FS_4 0x02
40 #define KXSD9_FS_2 0x03
41 #define KXSD9_FS_MASK 0x03
42
43 #define KXSD9_REG_CTRL_B 0x0d
44 #define KXSD9_REG_CTRL_A 0x0e
45
46 #define KXSD9_READ(a) (0x80 | (a))
47 #define KXSD9_WRITE(a) (a)
48
49 #define KXSD9_SCALE_2G "0.011978"
50 #define KXSD9_SCALE_4G "0.023927"
51 #define KXSD9_SCALE_6G "0.035934"
52 #define KXSD9_SCALE_8G "0.047853"
53
54 #define KXSD9_STATE_RX_SIZE 2
55 #define KXSD9_STATE_TX_SIZE 4
56 /**
57 * struct kxsd9_state - device related storage
58 * @buf_lock: protect the rx and tx buffers.
59 * @us: spi device
60 * @rx: single rx buffer storage
61 * @tx: single tx buffer storage
62 **/
63 struct kxsd9_state {
64 struct mutex buf_lock;
65 struct spi_device *us;
66 u8 rx[KXSD9_STATE_RX_SIZE] ____cacheline_aligned;
67 u8 tx[KXSD9_STATE_TX_SIZE];
68 };
69
70 /* This may want to move to mili g to allow for non integer ranges */
71 static ssize_t kxsd9_read_scale(struct device *dev,
72 struct device_attribute *attr,
73 char *buf)
74 {
75 int ret;
76 ssize_t len = 0;
77 struct iio_dev *indio_dev = dev_get_drvdata(dev);
78 struct kxsd9_state *st = iio_priv(indio_dev);
79 struct spi_transfer xfer = {
80 .bits_per_word = 8,
81 .len = 2,
82 .cs_change = 1,
83 .tx_buf = st->tx,
84 .rx_buf = st->rx,
85 };
86 struct spi_message msg;
87
88 mutex_lock(&st->buf_lock);
89 st->tx[0] = KXSD9_READ(KXSD9_REG_CTRL_C);
90 st->tx[1] = 0;
91 spi_message_init(&msg);
92 spi_message_add_tail(&xfer, &msg);
93 ret = spi_sync(st->us, &msg);
94 if (ret)
95 goto error_ret;
96
97 switch (st->rx[1] & KXSD9_FS_MASK) {
98 case KXSD9_FS_8:
99 len += sprintf(buf, "%s\n", KXSD9_SCALE_8G);
100 break;
101 case KXSD9_FS_6:
102 len += sprintf(buf, "%s\n", KXSD9_SCALE_6G);
103 break;
104 case KXSD9_FS_4:
105 len += sprintf(buf, "%s\n", KXSD9_SCALE_4G);
106 break;
107 case KXSD9_FS_2:
108 len += sprintf(buf, "%s\n", KXSD9_SCALE_2G);
109 break;
110 }
111
112 error_ret:
113 mutex_unlock(&st->buf_lock);
114
115 return ret ? ret : len;
116 }
117 static ssize_t kxsd9_write_scale(struct device *dev,
118 struct device_attribute *attr,
119 const char *buf,
120 size_t len)
121 {
122
123 struct spi_message msg;
124 int ret;
125 struct iio_dev *indio_dev = dev_get_drvdata(dev);
126 struct kxsd9_state *st = iio_priv(indio_dev);
127 u8 val;
128 struct spi_transfer xfers[] = {
129 {
130 .bits_per_word = 8,
131 .len = 2,
132 .cs_change = 1,
133 .tx_buf = st->tx,
134 .rx_buf = st->rx,
135 }, {
136 .bits_per_word = 8,
137 .len = 2,
138 .cs_change = 1,
139 .tx_buf = st->tx,
140 },
141 };
142
143 if (!strncmp(buf, KXSD9_SCALE_8G,
144 strlen(buf) < strlen(KXSD9_SCALE_8G)
145 ? strlen(buf) : strlen(KXSD9_SCALE_8G)))
146 val = KXSD9_FS_8;
147 else if (!strncmp(buf, KXSD9_SCALE_6G,
148 strlen(buf) < strlen(KXSD9_SCALE_6G)
149 ? strlen(buf) : strlen(KXSD9_SCALE_6G)))
150 val = KXSD9_FS_6;
151 else if (!strncmp(buf, KXSD9_SCALE_4G,
152 strlen(buf) < strlen(KXSD9_SCALE_4G)
153 ? strlen(buf) : strlen(KXSD9_SCALE_4G)))
154 val = KXSD9_FS_4;
155 else if (!strncmp(buf, KXSD9_SCALE_2G,
156 strlen(buf) < strlen(KXSD9_SCALE_2G)
157 ? strlen(buf) : strlen(KXSD9_SCALE_2G)))
158 val = KXSD9_FS_2;
159 else
160 return -EINVAL;
161
162 mutex_lock(&st->buf_lock);
163 st->tx[0] = KXSD9_READ(KXSD9_REG_CTRL_C);
164 st->tx[1] = 0;
165 spi_message_init(&msg);
166 spi_message_add_tail(&xfers[0], &msg);
167 ret = spi_sync(st->us, &msg);
168 if (ret)
169 goto error_ret;
170 st->tx[0] = KXSD9_WRITE(KXSD9_REG_CTRL_C);
171 st->tx[1] = (st->rx[1] & ~KXSD9_FS_MASK) | val;
172
173 spi_message_init(&msg);
174 spi_message_add_tail(&xfers[1], &msg);
175 ret = spi_sync(st->us, &msg);
176 error_ret:
177 mutex_unlock(&st->buf_lock);
178 return ret ? ret : len;
179 }
180
181 static ssize_t kxsd9_read_accel(struct device *dev,
182 struct device_attribute *attr,
183 char *buf)
184 {
185 struct spi_message msg;
186 int ret;
187 ssize_t len = 0;
188 u16 val;
189 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
190 struct iio_dev *indio_dev = dev_get_drvdata(dev);
191 struct kxsd9_state *st = iio_priv(indio_dev);
192 struct spi_transfer xfers[] = {
193 {
194 .bits_per_word = 8,
195 .len = 1,
196 .cs_change = 0,
197 .delay_usecs = 200,
198 .tx_buf = st->tx,
199 }, {
200 .bits_per_word = 8,
201 .len = 2,
202 .cs_change = 1,
203 .rx_buf = st->rx,
204 },
205 };
206
207 mutex_lock(&st->buf_lock);
208 st->tx[0] = KXSD9_READ(this_attr->address);
209 spi_message_init(&msg);
210 spi_message_add_tail(&xfers[0], &msg);
211 spi_message_add_tail(&xfers[1], &msg);
212 ret = spi_sync(st->us, &msg);
213 if (ret)
214 goto error_ret;
215 val = (((u16)(st->rx[0])) << 8) | (st->rx[1] & 0xF0);
216 len = sprintf(buf, "%d\n", val);
217 error_ret:
218 mutex_unlock(&st->buf_lock);
219
220 return ret ? ret : len;
221 }
222
223 static IIO_DEV_ATTR_ACCEL_X(kxsd9_read_accel, KXSD9_REG_X);
224 static IIO_DEV_ATTR_ACCEL_Y(kxsd9_read_accel, KXSD9_REG_Y);
225 static IIO_DEV_ATTR_ACCEL_Z(kxsd9_read_accel, KXSD9_REG_Z);
226 static IIO_DEV_ATTR_IN_RAW(0, kxsd9_read_accel, KXSD9_REG_AUX);
227
228 static IIO_DEVICE_ATTR(accel_scale,
229 S_IRUGO | S_IWUSR,
230 kxsd9_read_scale,
231 kxsd9_write_scale,
232 0);
233
234 static IIO_CONST_ATTR(accel_scale_available,
235 KXSD9_SCALE_2G " "
236 KXSD9_SCALE_4G " "
237 KXSD9_SCALE_6G " "
238 KXSD9_SCALE_8G);
239
240 static struct attribute *kxsd9_attributes[] = {
241 &iio_dev_attr_accel_x_raw.dev_attr.attr,
242 &iio_dev_attr_accel_y_raw.dev_attr.attr,
243 &iio_dev_attr_accel_z_raw.dev_attr.attr,
244 &iio_dev_attr_in0_raw.dev_attr.attr,
245 &iio_dev_attr_accel_scale.dev_attr.attr,
246 &iio_const_attr_accel_scale_available.dev_attr.attr,
247 NULL,
248 };
249
250 static const struct attribute_group kxsd9_attribute_group = {
251 .attrs = kxsd9_attributes,
252 };
253
254 static int __devinit kxsd9_power_up(struct kxsd9_state *st)
255 {
256 struct spi_transfer xfers[2] = {
257 {
258 .bits_per_word = 8,
259 .len = 2,
260 .cs_change = 1,
261 .tx_buf = st->tx,
262 }, {
263 .bits_per_word = 8,
264 .len = 2,
265 .cs_change = 1,
266 .tx_buf = st->tx + 2,
267 },
268 };
269 struct spi_message msg;
270 st->tx[0] = 0x0d;
271 st->tx[1] = 0x40;
272 st->tx[2] = 0x0c;
273 st->tx[3] = 0x9b;
274
275 spi_message_init(&msg);
276 spi_message_add_tail(&xfers[0], &msg);
277 spi_message_add_tail(&xfers[1], &msg);
278
279 return spi_sync(st->us, &msg);
280 };
281
282 static const struct iio_info kxsd9_info = {
283 .attrs = &kxsd9_attribute_group,
284 .driver_module = THIS_MODULE,
285 };
286
287 static int __devinit kxsd9_probe(struct spi_device *spi)
288 {
289 struct iio_dev *indio_dev;
290 struct kxsd9_state *st;
291 int ret = 0;
292
293 indio_dev = iio_allocate_device(sizeof(*st));
294 if (indio_dev == NULL) {
295 ret = -ENOMEM;
296 goto error_ret;
297 }
298 st = iio_priv(indio_dev);
299 spi_set_drvdata(spi, indio_dev);
300
301 st->us = spi;
302 mutex_init(&st->buf_lock);
303
304 indio_dev->dev.parent = &spi->dev;
305 indio_dev->info = &kxsd9_info;
306 indio_dev->modes = INDIO_DIRECT_MODE;
307
308 ret = iio_device_register(indio_dev);
309 if (ret)
310 goto error_free_dev;
311
312 spi->mode = SPI_MODE_0;
313 spi_setup(spi);
314 kxsd9_power_up(st);
315
316 return 0;
317
318 error_free_dev:
319 iio_free_device(indio_dev);
320 error_ret:
321 return ret;
322 }
323
324 static int __devexit kxsd9_remove(struct spi_device *spi)
325 {
326 iio_device_unregister(spi_get_drvdata(spi));
327
328 return 0;
329 }
330
331 static struct spi_driver kxsd9_driver = {
332 .driver = {
333 .name = "kxsd9",
334 .owner = THIS_MODULE,
335 },
336 .probe = kxsd9_probe,
337 .remove = __devexit_p(kxsd9_remove),
338 };
339
340 static __init int kxsd9_spi_init(void)
341 {
342 return spi_register_driver(&kxsd9_driver);
343 }
344 module_init(kxsd9_spi_init);
345
346 static __exit void kxsd9_spi_exit(void)
347 {
348 spi_unregister_driver(&kxsd9_driver);
349 }
350 module_exit(kxsd9_spi_exit);
351
352 MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
353 MODULE_DESCRIPTION("Kionix KXSD9 SPI driver");
354 MODULE_LICENSE("GPL v2");
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