/drivers/staging/iio/accel/sca3000.h
C Header | 270 lines | 110 code | 33 blank | 127 comment | 0 complexity | 96255c0619755eaf6f0b4df873bd60f6 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
1/*
2 * sca3000.c -- support VTI sca3000 series accelerometers
3 * via SPI
4 *
5 * Copyright (c) 2007 Jonathan Cameron <jic23@cam.ac.uk>
6 *
7 * Partly based upon tle62x0.c
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 * Initial mode is direct measurement.
14 *
15 * Untested things
16 *
17 * Temperature reading (the e05 I'm testing with doesn't have a sensor)
18 *
19 * Free fall detection mode - supported but untested as I'm not droping my
20 * dubious wire rig far enough to test it.
21 *
22 * Unsupported as yet
23 *
24 * Time stamping of data from ring. Various ideas on how to do this but none
25 * are remotely simple. Suggestions welcome.
26 *
27 * Individual enabling disabling of channels going into ring buffer
28 *
29 * Overflow handling (this is signaled for all but 8 bit ring buffer mode.)
30 *
31 * Motion detector using AND combinations of signals.
32 *
33 * Note: Be very careful about not touching an register bytes marked
34 * as reserved on the data sheet. They really mean it as changing convents of
35 * some will cause the device to lock up.
36 *
37 * Known issues - on rare occasions the interrupts lock up. Not sure why as yet.
38 * Can probably alleviate this by reading the interrupt register on start, but
39 * that is really just brushing the problem under the carpet.
40 */
41#define SCA3000_WRITE_REG(a) (((a) << 2) | 0x02)
42#define SCA3000_READ_REG(a) ((a) << 2)
43
44#define SCA3000_REG_ADDR_REVID 0x00
45#define SCA3000_REVID_MAJOR_MASK 0xf0
46#define SCA3000_REVID_MINOR_MASK 0x0f
47
48#define SCA3000_REG_ADDR_STATUS 0x02
49#define SCA3000_LOCKED 0x20
50#define SCA3000_EEPROM_CS_ERROR 0x02
51#define SCA3000_SPI_FRAME_ERROR 0x01
52
53/* All reads done using register decrement so no need to directly access LSBs */
54#define SCA3000_REG_ADDR_X_MSB 0x05
55#define SCA3000_REG_ADDR_Y_MSB 0x07
56#define SCA3000_REG_ADDR_Z_MSB 0x09
57
58#define SCA3000_REG_ADDR_RING_OUT 0x0f
59
60/* Temp read untested - the e05 doesn't have the sensor */
61#define SCA3000_REG_ADDR_TEMP_MSB 0x13
62
63#define SCA3000_REG_ADDR_MODE 0x14
64#define SCA3000_MODE_PROT_MASK 0x28
65
66#define SCA3000_RING_BUF_ENABLE 0x80
67#define SCA3000_RING_BUF_8BIT 0x40
68/* Free fall detection triggers an interrupt if the acceleration
69 * is below a threshold for equivalent of 25cm drop
70 */
71#define SCA3000_FREE_FALL_DETECT 0x10
72#define SCA3000_MEAS_MODE_NORMAL 0x00
73#define SCA3000_MEAS_MODE_OP_1 0x01
74#define SCA3000_MEAS_MODE_OP_2 0x02
75
76/* In motion detection mode the accelerations are band pass filtered
77 * (aprox 1 - 25Hz) and then a programmable threshold used to trigger
78 * and interrupt.
79 */
80#define SCA3000_MEAS_MODE_MOT_DET 0x03
81
82#define SCA3000_REG_ADDR_BUF_COUNT 0x15
83
84#define SCA3000_REG_ADDR_INT_STATUS 0x16
85
86#define SCA3000_INT_STATUS_THREE_QUARTERS 0x80
87#define SCA3000_INT_STATUS_HALF 0x40
88
89#define SCA3000_INT_STATUS_FREE_FALL 0x08
90#define SCA3000_INT_STATUS_Y_TRIGGER 0x04
91#define SCA3000_INT_STATUS_X_TRIGGER 0x02
92#define SCA3000_INT_STATUS_Z_TRIGGER 0x01
93
94/* Used to allow access to multiplexed registers */
95#define SCA3000_REG_ADDR_CTRL_SEL 0x18
96/* Only available for SCA3000-D03 and SCA3000-D01 */
97#define SCA3000_REG_CTRL_SEL_I2C_DISABLE 0x01
98#define SCA3000_REG_CTRL_SEL_MD_CTRL 0x02
99#define SCA3000_REG_CTRL_SEL_MD_Y_TH 0x03
100#define SCA3000_REG_CTRL_SEL_MD_X_TH 0x04
101#define SCA3000_REG_CTRL_SEL_MD_Z_TH 0x05
102/* BE VERY CAREFUL WITH THIS, IF 3 BITS ARE NOT SET the device
103 will not function */
104#define SCA3000_REG_CTRL_SEL_OUT_CTRL 0x0B
105#define SCA3000_OUT_CTRL_PROT_MASK 0xE0
106#define SCA3000_OUT_CTRL_BUF_X_EN 0x10
107#define SCA3000_OUT_CTRL_BUF_Y_EN 0x08
108#define SCA3000_OUT_CTRL_BUF_Z_EN 0x04
109#define SCA3000_OUT_CTRL_BUF_DIV_4 0x02
110#define SCA3000_OUT_CTRL_BUF_DIV_2 0x01
111
112/* Control which motion detector interrupts are on.
113 * For now only OR combinations are supported.x
114 */
115#define SCA3000_MD_CTRL_PROT_MASK 0xC0
116#define SCA3000_MD_CTRL_OR_Y 0x01
117#define SCA3000_MD_CTRL_OR_X 0x02
118#define SCA3000_MD_CTRL_OR_Z 0x04
119/* Currently unsupported */
120#define SCA3000_MD_CTRL_AND_Y 0x08
121#define SCA3000_MD_CTRL_AND_X 0x10
122#define SAC3000_MD_CTRL_AND_Z 0x20
123
124/* Some control registers of complex access methods requiring this register to
125 * be used to remove a lock.
126 */
127#define SCA3000_REG_ADDR_UNLOCK 0x1e
128
129#define SCA3000_REG_ADDR_INT_MASK 0x21
130#define SCA3000_INT_MASK_PROT_MASK 0x1C
131
132#define SCA3000_INT_MASK_RING_THREE_QUARTER 0x80
133#define SCA3000_INT_MASK_RING_HALF 0x40
134
135#define SCA3000_INT_MASK_ALL_INTS 0x02
136#define SCA3000_INT_MASK_ACTIVE_HIGH 0x01
137#define SCA3000_INT_MASK_ACTIVE_LOW 0x00
138
139/* Values of mulipexed registers (write to ctrl_data after select) */
140#define SCA3000_REG_ADDR_CTRL_DATA 0x22
141
142/* Measurement modes available on some sca3000 series chips. Code assumes others
143 * may become available in the future.
144 *
145 * Bypass - Bypass the low-pass filter in the signal channel so as to increase
146 * signal bandwidth.
147 *
148 * Narrow - Narrow low-pass filtering of the signal channel and half output
149 * data rate by decimation.
150 *
151 * Wide - Widen low-pass filtering of signal channel to increase bandwidth
152 */
153#define SCA3000_OP_MODE_BYPASS 0x01
154#define SCA3000_OP_MODE_NARROW 0x02
155#define SCA3000_OP_MODE_WIDE 0x04
156#define SCA3000_MAX_TX 6
157#define SCA3000_MAX_RX 2
158
159/**
160 * struct sca3000_state - device instance state information
161 * @us: the associated spi device
162 * @info: chip variant information
163 * @indio_dev: device information used by the IIO core
164 * @interrupt_handler_ws: event interrupt handler for all events
165 * @last_timestamp: the timestamp of the last event
166 * @mo_det_use_count: reference counter for the motion detection unit
167 * @lock: lock used to protect elements of sca3000_state
168 * and the underlying device state.
169 * @bpse: number of bits per scan element
170 * @tx: dma-able transmit buffer
171 * @rx: dma-able receive buffer
172 **/
173struct sca3000_state {
174 struct spi_device *us;
175 const struct sca3000_chip_info *info;
176 struct iio_dev *indio_dev;
177 struct work_struct interrupt_handler_ws;
178 s64 last_timestamp;
179 int mo_det_use_count;
180 struct mutex lock;
181 int bpse;
182 /* Can these share a cacheline ? */
183 u8 rx[2] ____cacheline_aligned;
184 u8 tx[6] ____cacheline_aligned;
185};
186
187/**
188 * struct sca3000_chip_info - model dependent parameters
189 * @scale: scale * 10^-6
190 * @temp_output: some devices have temperature sensors.
191 * @measurement_mode_freq: normal mode sampling frequency
192 * @option_mode_1: first optional mode. Not all models have one
193 * @option_mode_1_freq: option mode 1 sampling frequency
194 * @option_mode_2: second optional mode. Not all chips have one
195 * @option_mode_2_freq: option mode 2 sampling frequency
196 *
197 * This structure is used to hold information about the functionality of a given
198 * sca3000 variant.
199 **/
200struct sca3000_chip_info {
201 unsigned int scale;
202 bool temp_output;
203 int measurement_mode_freq;
204 int option_mode_1;
205 int option_mode_1_freq;
206 int option_mode_2;
207 int option_mode_2_freq;
208 int mot_det_mult_xz[6];
209 int mot_det_mult_y[7];
210};
211
212int sca3000_read_data_short(struct sca3000_state *st,
213 u8 reg_address_high,
214 int len);
215
216/**
217 * sca3000_write_reg() write a single register
218 * @address: address of register on chip
219 * @val: value to be written to register
220 *
221 * The main lock must be held.
222 **/
223int sca3000_write_reg(struct sca3000_state *st, u8 address, u8 val);
224
225#ifdef CONFIG_IIO_RING_BUFFER
226/**
227 * sca3000_register_ring_funcs() setup the ring state change functions
228 **/
229void sca3000_register_ring_funcs(struct iio_dev *indio_dev);
230
231/**
232 * sca3000_configure_ring() - allocate and configure ring buffer
233 * @indio_dev: iio-core device whose ring is to be configured
234 *
235 * The hardware ring buffer needs far fewer ring buffer functions than
236 * a software one as a lot of things are handled automatically.
237 * This function also tells the iio core that our device supports a
238 * hardware ring buffer mode.
239 **/
240int sca3000_configure_ring(struct iio_dev *indio_dev);
241
242/**
243 * sca3000_unconfigure_ring() - deallocate the ring buffer
244 * @indio_dev: iio-core device whose ring we are freeing
245 **/
246void sca3000_unconfigure_ring(struct iio_dev *indio_dev);
247
248/**
249 * sca3000_ring_int_process() handles ring related event pushing and escalation
250 * @val: the event code
251 **/
252void sca3000_ring_int_process(u8 val, struct iio_ring_buffer *ring);
253
254#else
255static inline void sca3000_register_ring_funcs(struct iio_dev *indio_dev)
256{
257}
258
259static inline
260int sca3000_register_ring_access_and_init(struct iio_dev *indio_dev)
261{
262 return 0;
263}
264
265static inline void sca3000_ring_int_process(u8 val, void *ring)
266{
267}
268
269#endif
270