drivers/staging/iio/accel/sca3000.h - kernel/bruno - Git at Google

 /*
  * sca3000.c -- support VTI sca3000 series accelerometers
  *              via SPI
  *
  * Copyright (c) 2007 Jonathan Cameron <jic23@kernel.org>
  *
  * 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.
  */
 #ifndef _SCA3000
 #define _SCA3000

 #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
  * (approx 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 access 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.
  */
 #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 multiplexed 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
  * @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 work_struct		interrupt_handler_ws;
 	s64				last_timestamp;
 	int				mo_det_use_count;
 	struct mutex			lock;
 	int				bpse;
 	/* Can these share a cacheline ? */
 	u8				rx[2] ____cacheline_aligned;
 	u8				tx[6] ____cacheline_aligned;
 };

 /**
  * struct sca3000_chip_info - model dependent parameters
  * @scale:			scale * 10^-6
  * @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 {
 	unsigned int		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;
 	int			mot_det_mult_xz[6];
 	int			mot_det_mult_y[7];
 };

 int sca3000_read_data_short(struct sca3000_state *st,
 			    u8 reg_address_high,
 			    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);

 #ifdef CONFIG_IIO_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_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
 #endif /* _SCA3000 */
	/*
	* sca3000.c -- support VTI sca3000 series accelerometers
	* via SPI
	*
	* Copyright (c) 2007 Jonathan Cameron <jic23@kernel.org>
	*
	* 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.
	*/
	#ifndef _SCA3000
	#define _SCA3000

	#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
	* (approx 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 access 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.
	*/
	#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 multiplexed 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
	* @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 work_struct interrupt_handler_ws;
	s64 last_timestamp;
	int mo_det_use_count;
	struct mutex lock;
	int bpse;
	/* Can these share a cacheline ? */
	u8 rx[2] ____cacheline_aligned;
	u8 tx[6] ____cacheline_aligned;
	};

	/**
	* struct sca3000_chip_info - model dependent parameters
	* @scale: scale * 10^-6
	* @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 {
	unsigned int 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;
	int mot_det_mult_xz[6];
	int mot_det_mult_y[7];
	};

	int sca3000_read_data_short(struct sca3000_state *st,
	u8 reg_address_high,
	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);

	#ifdef CONFIG_IIO_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_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
	#endif /* _SCA3000 */