/drivers/staging/iio/accel/sca3000.h

  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