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Diffstat (limited to 'drivers/staging/iio/accel/sca3000.h')
| -rw-r--r-- | drivers/staging/iio/accel/sca3000.h | 298 |
1 files changed, 298 insertions, 0 deletions
diff --git a/drivers/staging/iio/accel/sca3000.h b/drivers/staging/iio/accel/sca3000.h new file mode 100644 index 000000000000..29e11da09572 --- /dev/null +++ b/drivers/staging/iio/accel/sca3000.h @@ -0,0 +1,298 @@ +/* + * sca3000.c -- support VTI sca3000 series accelerometers + * via SPI + * + * Copyright (c) 2007 Jonathan Cameron <jic23@cam.ac.uk> + * + * 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 theshold 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 + +/* Measurment 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 + * @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; + 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 + |