/* * sca3000.c -- support VTI sca3000 series accelerometers * via SPI * * Copyright (c) 2007 Jonathan Cameron * * Partly based upon tle62x0.c * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * Initial mode is direct measurement. * * Untested things * * Temperature reading (the e05 I'm testing with doesn't have a sensor) * * Free fall detection mode - supported but untested as I'm not droping my * dubious wire rig far enough to test it. * * Unsupported as yet * * Time stamping of data from ring. Various ideas on how to do this but none * are remotely simple. Suggestions welcome. * * Individual enabling disabling of channels going into ring buffer * * Overflow handling (this is signaled for all but 8 bit ring buffer mode.) * * Motion detector using AND combinations of signals. * * Note: Be very careful about not touching an register bytes marked * as reserved on the data sheet. They really mean it as changing convents of * some will cause the device to lock up. * * Known issues - on rare occasions the interrupts lock up. Not sure why as yet. * Can probably alleviate this by reading the interrupt register on start, but * that is really just brushing the problem under the carpet. */ #define SCA3000_WRITE_REG(a) (((a) << 2) | 0x02) #define SCA3000_READ_REG(a) ((a) << 2) #define SCA3000_REG_ADDR_REVID 0x00 #define SCA3000_REVID_MAJOR_MASK 0xf0 #define SCA3000_REVID_MINOR_MASK 0x0f #define SCA3000_REG_ADDR_STATUS 0x02 #define SCA3000_LOCKED 0x20 #define SCA3000_EEPROM_CS_ERROR 0x02 #define SCA3000_SPI_FRAME_ERROR 0x01 /* All reads done using register decrement so no need to directly access LSBs */ #define SCA3000_REG_ADDR_X_MSB 0x05 #define SCA3000_REG_ADDR_Y_MSB 0x07 #define SCA3000_REG_ADDR_Z_MSB 0x09 #define SCA3000_REG_ADDR_RING_OUT 0x0f /* Temp read untested - the e05 doesn't have the sensor */ #define SCA3000_REG_ADDR_TEMP_MSB 0x13 #define SCA3000_REG_ADDR_MODE 0x14 #define SCA3000_MODE_PROT_MASK 0x28 #define SCA3000_RING_BUF_ENABLE 0x80 #define SCA3000_RING_BUF_8BIT 0x40 /* Free fall detection triggers an interrupt if the acceleration * is below a threshold for equivalent of 25cm drop */ #define SCA3000_FREE_FALL_DETECT 0x10 #define SCA3000_MEAS_MODE_NORMAL 0x00 #define SCA3000_MEAS_MODE_OP_1 0x01 #define SCA3000_MEAS_MODE_OP_2 0x02 /* In motion detection mode the accelerations are band pass filtered * (aprox 1 - 25Hz) and then a programmable threshold used to trigger * and interrupt. */ #define SCA3000_MEAS_MODE_MOT_DET 0x03 #define SCA3000_REG_ADDR_BUF_COUNT 0x15 #define SCA3000_REG_ADDR_INT_STATUS 0x16 #define SCA3000_INT_STATUS_THREE_QUARTERS 0x80 #define SCA3000_INT_STATUS_HALF 0x40 #define SCA3000_INT_STATUS_FREE_FALL 0x08 #define SCA3000_INT_STATUS_Y_TRIGGER 0x04 #define SCA3000_INT_STATUS_X_TRIGGER 0x02 #define SCA3000_INT_STATUS_Z_TRIGGER 0x01 /* Used to allow accesss to multiplexed registers */ #define SCA3000_REG_ADDR_CTRL_SEL 0x18 /* Only available for SCA3000-D03 and SCA3000-D01 */ #define SCA3000_REG_CTRL_SEL_I2C_DISABLE 0x01 #define SCA3000_REG_CTRL_SEL_MD_CTRL 0x02 #define SCA3000_REG_CTRL_SEL_MD_Y_TH 0x03 #define SCA3000_REG_CTRL_SEL_MD_X_TH 0x04 #define SCA3000_REG_CTRL_SEL_MD_Z_TH 0x05 /* BE VERY CAREFUL WITH THIS, IF 3 BITS ARE NOT SET the device will not function */ #define SCA3000_REG_CTRL_SEL_OUT_CTRL 0x0B #define SCA3000_OUT_CTRL_PROT_MASK 0xE0 #define SCA3000_OUT_CTRL_BUF_X_EN 0x10 #define SCA3000_OUT_CTRL_BUF_Y_EN 0x08 #define SCA3000_OUT_CTRL_BUF_Z_EN 0x04 #define SCA3000_OUT_CTRL_BUF_DIV_4 0x02 #define SCA3000_OUT_CTRL_BUF_DIV_2 0x01 /* Control which motion detector interrupts are on. * For now only OR combinations are supported.x */ #define SCA3000_MD_CTRL_PROT_MASK 0xC0 #define SCA3000_MD_CTRL_OR_Y 0x01 #define SCA3000_MD_CTRL_OR_X 0x02 #define SCA3000_MD_CTRL_OR_Z 0x04 /* Currently unsupported */ #define SCA3000_MD_CTRL_AND_Y 0x08 #define SCA3000_MD_CTRL_AND_X 0x10 #define SAC3000_MD_CTRL_AND_Z 0x20 /* Some control registers of complex access methods requiring this register to * be used to remove a lock. */ #define SCA3000_REG_ADDR_UNLOCK 0x1e #define SCA3000_REG_ADDR_INT_MASK 0x21 #define SCA3000_INT_MASK_PROT_MASK 0x1C #define SCA3000_INT_MASK_RING_THREE_QUARTER 0x80 #define SCA3000_INT_MASK_RING_HALF 0x40 #define SCA3000_INT_MASK_ALL_INTS 0x02 #define SCA3000_INT_MASK_ACTIVE_HIGH 0x01 #define SCA3000_INT_MASK_ACTIVE_LOW 0x00 /* Values of mulipexed registers (write to ctrl_data after select) */ #define SCA3000_REG_ADDR_CTRL_DATA 0x22 /* Measurement modes available on some sca3000 series chips. Code assumes others * may become available in the future. * * Bypass - Bypass the low-pass filter in the signal channel so as to increase * signal bandwidth. * * Narrow - Narrow low-pass filtering of the signal channel and half output * data rate by decimation. * * Wide - Widen low-pass filtering of signal channel to increase bandwidth */ #define SCA3000_OP_MODE_BYPASS 0x01 #define SCA3000_OP_MODE_NARROW 0x02 #define SCA3000_OP_MODE_WIDE 0x04 #define SCA3000_MAX_TX 6 #define SCA3000_MAX_RX 2 /** * struct sca3000_state - device instance state information * @us: the associated spi device * @info: chip variant information * @indio_dev: device information used by the IIO core * @interrupt_handler_ws: event interrupt handler for all events * @last_timestamp: the timestamp of the last event * @mo_det_use_count: reference counter for the motion detection unit * @lock: lock used to protect elements of sca3000_state * and the underlying device state. * @bpse: number of bits per scan element * @tx: dma-able transmit buffer * @rx: dma-able receive buffer **/ struct sca3000_state { struct spi_device *us; const struct sca3000_chip_info *info; struct iio_dev *indio_dev; struct work_struct interrupt_handler_ws; s64 last_timestamp; int mo_det_use_count; struct mutex lock; int bpse; u8 *tx; /* not used during a ring buffer read */ u8 *rx; }; /** * struct sca3000_chip_info - model dependant parameters * @name: model identification * @scale: string containing floating point scale factor * @temp_output: some devices have temperature sensors. * @measurement_mode_freq: normal mode sampling frequency * @option_mode_1: first optional mode. Not all models have one * @option_mode_1_freq: option mode 1 sampling frequency * @option_mode_2: second optional mode. Not all chips have one * @option_mode_2_freq: option mode 2 sampling frequency * * This structure is used to hold information about the functionality of a given * sca3000 variant. **/ struct sca3000_chip_info { const char *name; const char *scale; bool temp_output; int measurement_mode_freq; int option_mode_1; int option_mode_1_freq; int option_mode_2; int option_mode_2_freq; }; /** * sca3000_read_data() read a series of values from the device * @dev: device * @reg_address_high: start address (decremented read) * @rx: pointer where recieved data is placed. Callee * responsible for freeing this. * @len: number of bytes to read * * The main lock must be held. **/ int sca3000_read_data(struct sca3000_state *st, u8 reg_address_high, u8 **rx_p, int len); /** * sca3000_write_reg() write a single register * @address: address of register on chip * @val: value to be written to register * * The main lock must be held. **/ int sca3000_write_reg(struct sca3000_state *st, u8 address, u8 val); /* Conversion function for use with the ring buffer when in 11bit mode */ static inline int sca3000_11bit_convert(uint8_t msb, uint8_t lsb) { int16_t val; val = ((lsb >> 3) & 0x1C) | (msb << 5); val |= (val & (1 << 12)) ? 0xE000 : 0; return val; }; static inline int sca3000_13bit_convert(uint8_t msb, uint8_t lsb) { s16 val; val = ((lsb >> 3) & 0x1F) | (msb << 5); /* sign fill */ val |= (val & (1 << 12)) ? 0xE000 : 0; return val; }; #ifdef CONFIG_IIO_RING_BUFFER /** * sca3000_register_ring_funcs() setup the ring state change functions **/ void sca3000_register_ring_funcs(struct iio_dev *indio_dev); /** * sca3000_configure_ring() - allocate and configure ring buffer * @indio_dev: iio-core device whose ring is to be configured * * The hardware ring buffer needs far fewer ring buffer functions than * a software one as a lot of things are handled automatically. * This function also tells the iio core that our device supports a * hardware ring buffer mode. **/ int sca3000_configure_ring(struct iio_dev *indio_dev); /** * sca3000_unconfigure_ring() - deallocate the ring buffer * @indio_dev: iio-core device whose ring we are freeing **/ void sca3000_unconfigure_ring(struct iio_dev *indio_dev); /** * sca3000_ring_int_process() handles ring related event pushing and escalation * @val: the event code **/ void sca3000_ring_int_process(u8 val, struct iio_ring_buffer *ring); #else static inline void sca3000_register_ring_funcs(struct iio_dev *indio_dev) {}; static inline int sca3000_register_ring_access_and_init(struct iio_dev *indio_dev) { return 0; }; static inline void sca3000_ring_int_process(u8 val, void *ring) {}; #endif