2 * sca3000.c -- support VTI sca3000 series accelerometers
5 * Copyright (c) 2007 Jonathan Cameron <jic23@kernel.org>
7 * Partly based upon tle62x0.c
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.
13 * Initial mode is direct measurement.
17 * Temperature reading (the e05 I'm testing with doesn't have a sensor)
19 * Free fall detection mode - supported but untested as I'm not droping my
20 * dubious wire rig far enough to test it.
24 * Time stamping of data from ring. Various ideas on how to do this but none
25 * are remotely simple. Suggestions welcome.
27 * Individual enabling disabling of channels going into ring buffer
29 * Overflow handling (this is signaled for all but 8 bit ring buffer mode.)
31 * Motion detector using AND combinations of signals.
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.
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.
44 #define SCA3000_WRITE_REG(a) (((a) << 2) | 0x02)
45 #define SCA3000_READ_REG(a) ((a) << 2)
47 #define SCA3000_REG_ADDR_REVID 0x00
48 #define SCA3000_REVID_MAJOR_MASK 0xf0
49 #define SCA3000_REVID_MINOR_MASK 0x0f
51 #define SCA3000_REG_ADDR_STATUS 0x02
52 #define SCA3000_LOCKED 0x20
53 #define SCA3000_EEPROM_CS_ERROR 0x02
54 #define SCA3000_SPI_FRAME_ERROR 0x01
56 /* All reads done using register decrement so no need to directly access LSBs */
57 #define SCA3000_REG_ADDR_X_MSB 0x05
58 #define SCA3000_REG_ADDR_Y_MSB 0x07
59 #define SCA3000_REG_ADDR_Z_MSB 0x09
61 #define SCA3000_REG_ADDR_RING_OUT 0x0f
63 /* Temp read untested - the e05 doesn't have the sensor */
64 #define SCA3000_REG_ADDR_TEMP_MSB 0x13
66 #define SCA3000_REG_ADDR_MODE 0x14
67 #define SCA3000_MODE_PROT_MASK 0x28
69 #define SCA3000_RING_BUF_ENABLE 0x80
70 #define SCA3000_RING_BUF_8BIT 0x40
72 * Free fall detection triggers an interrupt if the acceleration
73 * is below a threshold for equivalent of 25cm drop
75 #define SCA3000_FREE_FALL_DETECT 0x10
76 #define SCA3000_MEAS_MODE_NORMAL 0x00
77 #define SCA3000_MEAS_MODE_OP_1 0x01
78 #define SCA3000_MEAS_MODE_OP_2 0x02
81 * In motion detection mode the accelerations are band pass filtered
82 * (approx 1 - 25Hz) and then a programmable threshold used to trigger
85 #define SCA3000_MEAS_MODE_MOT_DET 0x03
87 #define SCA3000_REG_ADDR_BUF_COUNT 0x15
89 #define SCA3000_REG_ADDR_INT_STATUS 0x16
91 #define SCA3000_INT_STATUS_THREE_QUARTERS 0x80
92 #define SCA3000_INT_STATUS_HALF 0x40
94 #define SCA3000_INT_STATUS_FREE_FALL 0x08
95 #define SCA3000_INT_STATUS_Y_TRIGGER 0x04
96 #define SCA3000_INT_STATUS_X_TRIGGER 0x02
97 #define SCA3000_INT_STATUS_Z_TRIGGER 0x01
99 /* Used to allow access to multiplexed registers */
100 #define SCA3000_REG_ADDR_CTRL_SEL 0x18
101 /* Only available for SCA3000-D03 and SCA3000-D01 */
102 #define SCA3000_REG_CTRL_SEL_I2C_DISABLE 0x01
103 #define SCA3000_REG_CTRL_SEL_MD_CTRL 0x02
104 #define SCA3000_REG_CTRL_SEL_MD_Y_TH 0x03
105 #define SCA3000_REG_CTRL_SEL_MD_X_TH 0x04
106 #define SCA3000_REG_CTRL_SEL_MD_Z_TH 0x05
108 * BE VERY CAREFUL WITH THIS, IF 3 BITS ARE NOT SET the device
111 #define SCA3000_REG_CTRL_SEL_OUT_CTRL 0x0B
112 #define SCA3000_OUT_CTRL_PROT_MASK 0xE0
113 #define SCA3000_OUT_CTRL_BUF_X_EN 0x10
114 #define SCA3000_OUT_CTRL_BUF_Y_EN 0x08
115 #define SCA3000_OUT_CTRL_BUF_Z_EN 0x04
116 #define SCA3000_OUT_CTRL_BUF_DIV_MASK 0x03
117 #define SCA3000_OUT_CTRL_BUF_DIV_4 0x02
118 #define SCA3000_OUT_CTRL_BUF_DIV_2 0x01
121 * Control which motion detector interrupts are on.
122 * For now only OR combinations are supported.
124 #define SCA3000_MD_CTRL_PROT_MASK 0xC0
125 #define SCA3000_MD_CTRL_OR_Y 0x01
126 #define SCA3000_MD_CTRL_OR_X 0x02
127 #define SCA3000_MD_CTRL_OR_Z 0x04
128 /* Currently unsupported */
129 #define SCA3000_MD_CTRL_AND_Y 0x08
130 #define SCA3000_MD_CTRL_AND_X 0x10
131 #define SAC3000_MD_CTRL_AND_Z 0x20
134 * Some control registers of complex access methods requiring this register to
135 * be used to remove a lock.
137 #define SCA3000_REG_ADDR_UNLOCK 0x1e
139 #define SCA3000_REG_ADDR_INT_MASK 0x21
140 #define SCA3000_INT_MASK_PROT_MASK 0x1C
142 #define SCA3000_INT_MASK_RING_THREE_QUARTER 0x80
143 #define SCA3000_INT_MASK_RING_HALF 0x40
145 #define SCA3000_INT_MASK_ALL_INTS 0x02
146 #define SCA3000_INT_MASK_ACTIVE_HIGH 0x01
147 #define SCA3000_INT_MASK_ACTIVE_LOW 0x00
149 /* Values of multiplexed registers (write to ctrl_data after select) */
150 #define SCA3000_REG_ADDR_CTRL_DATA 0x22
153 * Measurement modes available on some sca3000 series chips. Code assumes others
154 * may become available in the future.
156 * Bypass - Bypass the low-pass filter in the signal channel so as to increase
159 * Narrow - Narrow low-pass filtering of the signal channel and half output
160 * data rate by decimation.
162 * Wide - Widen low-pass filtering of signal channel to increase bandwidth
164 #define SCA3000_OP_MODE_BYPASS 0x01
165 #define SCA3000_OP_MODE_NARROW 0x02
166 #define SCA3000_OP_MODE_WIDE 0x04
167 #define SCA3000_MAX_TX 6
168 #define SCA3000_MAX_RX 2
171 * struct sca3000_state - device instance state information
172 * @us: the associated spi device
173 * @info: chip variant information
174 * @interrupt_handler_ws: event interrupt handler for all events
175 * @last_timestamp: the timestamp of the last event
176 * @mo_det_use_count: reference counter for the motion detection unit
177 * @lock: lock used to protect elements of sca3000_state
178 * and the underlying device state.
179 * @bpse: number of bits per scan element
180 * @tx: dma-able transmit buffer
181 * @rx: dma-able receive buffer
183 struct sca3000_state {
184 struct spi_device *us;
185 const struct sca3000_chip_info *info;
186 struct work_struct interrupt_handler_ws;
188 int mo_det_use_count;
191 /* Can these share a cacheline ? */
192 u8 rx[2] ____cacheline_aligned;
193 u8 tx[6] ____cacheline_aligned;
197 * struct sca3000_chip_info - model dependent parameters
198 * @scale: scale * 10^-6
199 * @temp_output: some devices have temperature sensors.
200 * @measurement_mode_freq: normal mode sampling frequency
201 * @option_mode_1: first optional mode. Not all models have one
202 * @option_mode_1_freq: option mode 1 sampling frequency
203 * @option_mode_2: second optional mode. Not all chips have one
204 * @option_mode_2_freq: option mode 2 sampling frequency
206 * This structure is used to hold information about the functionality of a given
209 struct sca3000_chip_info {
212 int measurement_mode_freq;
214 int option_mode_1_freq;
216 int option_mode_2_freq;
217 int mot_det_mult_xz[6];
218 int mot_det_mult_y[7];
221 int sca3000_read_data_short(struct sca3000_state *st,
226 * sca3000_write_reg() write a single register
227 * @address: address of register on chip
228 * @val: value to be written to register
230 * The main lock must be held.
232 int sca3000_write_reg(struct sca3000_state *st, u8 address, u8 val);
234 #ifdef CONFIG_IIO_BUFFER
236 * sca3000_register_ring_funcs() setup the ring state change functions
238 void sca3000_register_ring_funcs(struct iio_dev *indio_dev);
241 * sca3000_configure_ring() - allocate and configure ring buffer
242 * @indio_dev: iio-core device whose ring is to be configured
244 * The hardware ring buffer needs far fewer ring buffer functions than
245 * a software one as a lot of things are handled automatically.
246 * This function also tells the iio core that our device supports a
247 * hardware ring buffer mode.
249 int sca3000_configure_ring(struct iio_dev *indio_dev);
252 * sca3000_unconfigure_ring() - deallocate the ring buffer
253 * @indio_dev: iio-core device whose ring we are freeing
255 void sca3000_unconfigure_ring(struct iio_dev *indio_dev);
258 * sca3000_ring_int_process() handles ring related event pushing and escalation
259 * @val: the event code
261 void sca3000_ring_int_process(u8 val, struct iio_buffer *ring);
264 static inline void sca3000_register_ring_funcs(struct iio_dev *indio_dev)
269 int sca3000_register_ring_access_and_init(struct iio_dev *indio_dev)
274 static inline void sca3000_ring_int_process(u8 val, void *ring)
279 #endif /* _SCA3000 */