// SPDX-License-Identifier: GPL-2.0-only /* * sca3000_core.c -- support VTI sca3000 series accelerometers via SPI * * Copyright (c) 2009 Jonathan Cameron <[email protected]> * * See industrialio/accels/sca3000.h for comments. */ #include <linux/interrupt.h> #include <linux/fs.h> #include <linux/device.h> #include <linux/slab.h> #include <linux/kernel.h> #include <linux/spi/spi.h> #include <linux/sysfs.h> #include <linux/module.h> #include <linux/uaccess.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h> #include <linux/iio/events.h> #include <linux/iio/buffer.h> #include <linux/iio/kfifo_buf.h> #define SCA3000_WRITE_REG(a) … #define SCA3000_READ_REG(a) … #define SCA3000_REG_REVID_ADDR … #define SCA3000_REG_REVID_MAJOR_MASK … #define SCA3000_REG_REVID_MINOR_MASK … #define SCA3000_REG_STATUS_ADDR … #define SCA3000_LOCKED … #define SCA3000_EEPROM_CS_ERROR … #define SCA3000_SPI_FRAME_ERROR … /* All reads done using register decrement so no need to directly access LSBs */ #define SCA3000_REG_X_MSB_ADDR … #define SCA3000_REG_Y_MSB_ADDR … #define SCA3000_REG_Z_MSB_ADDR … #define SCA3000_REG_RING_OUT_ADDR … /* Temp read untested - the e05 doesn't have the sensor */ #define SCA3000_REG_TEMP_MSB_ADDR … #define SCA3000_REG_MODE_ADDR … #define SCA3000_MODE_PROT_MASK … #define SCA3000_REG_MODE_RING_BUF_ENABLE … #define SCA3000_REG_MODE_RING_BUF_8BIT … /* * Free fall detection triggers an interrupt if the acceleration * is below a threshold for equivalent of 25cm drop */ #define SCA3000_REG_MODE_FREE_FALL_DETECT … #define SCA3000_REG_MODE_MEAS_MODE_NORMAL … #define SCA3000_REG_MODE_MEAS_MODE_OP_1 … #define SCA3000_REG_MODE_MEAS_MODE_OP_2 … /* * 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_REG_MODE_MEAS_MODE_MOT_DET … #define SCA3000_REG_MODE_MODE_MASK … #define SCA3000_REG_BUF_COUNT_ADDR … #define SCA3000_REG_INT_STATUS_ADDR … #define SCA3000_REG_INT_STATUS_THREE_QUARTERS … #define SCA3000_REG_INT_STATUS_HALF … #define SCA3000_INT_STATUS_FREE_FALL … #define SCA3000_INT_STATUS_Y_TRIGGER … #define SCA3000_INT_STATUS_X_TRIGGER … #define SCA3000_INT_STATUS_Z_TRIGGER … /* Used to allow access to multiplexed registers */ #define SCA3000_REG_CTRL_SEL_ADDR … /* Only available for SCA3000-D03 and SCA3000-D01 */ #define SCA3000_REG_CTRL_SEL_I2C_DISABLE … #define SCA3000_REG_CTRL_SEL_MD_CTRL … #define SCA3000_REG_CTRL_SEL_MD_Y_TH … #define SCA3000_REG_CTRL_SEL_MD_X_TH … #define SCA3000_REG_CTRL_SEL_MD_Z_TH … /* * BE VERY CAREFUL WITH THIS, IF 3 BITS ARE NOT SET the device * will not function */ #define SCA3000_REG_CTRL_SEL_OUT_CTRL … #define SCA3000_REG_OUT_CTRL_PROT_MASK … #define SCA3000_REG_OUT_CTRL_BUF_X_EN … #define SCA3000_REG_OUT_CTRL_BUF_Y_EN … #define SCA3000_REG_OUT_CTRL_BUF_Z_EN … #define SCA3000_REG_OUT_CTRL_BUF_DIV_MASK … #define SCA3000_REG_OUT_CTRL_BUF_DIV_4 … #define SCA3000_REG_OUT_CTRL_BUF_DIV_2 … /* * Control which motion detector interrupts are on. * For now only OR combinations are supported. */ #define SCA3000_MD_CTRL_PROT_MASK … #define SCA3000_MD_CTRL_OR_Y … #define SCA3000_MD_CTRL_OR_X … #define SCA3000_MD_CTRL_OR_Z … /* Currently unsupported */ #define SCA3000_MD_CTRL_AND_Y … #define SCA3000_MD_CTRL_AND_X … #define SCA3000_MD_CTRL_AND_Z … /* * Some control registers of complex access methods requiring this register to * be used to remove a lock. */ #define SCA3000_REG_UNLOCK_ADDR … #define SCA3000_REG_INT_MASK_ADDR … #define SCA3000_REG_INT_MASK_PROT_MASK … #define SCA3000_REG_INT_MASK_RING_THREE_QUARTER … #define SCA3000_REG_INT_MASK_RING_HALF … #define SCA3000_REG_INT_MASK_ALL_INTS … #define SCA3000_REG_INT_MASK_ACTIVE_HIGH … #define SCA3000_REG_INT_MASK_ACTIVE_LOW … /* Values of multiplexed registers (write to ctrl_data after select) */ #define SCA3000_REG_CTRL_DATA_ADDR … /* * 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 … #define SCA3000_OP_MODE_NARROW … #define SCA3000_OP_MODE_WIDE … #define SCA3000_MAX_TX … #define SCA3000_MAX_RX … /** * struct sca3000_state - device instance state information * @us: the associated spi device * @info: chip variant information * @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. * @tx: dma-able transmit buffer * @rx: dma-able receive buffer **/ struct sca3000_state { … }; /** * 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 * @measurement_mode_3db_freq: 3db cutoff frequency of the low pass filter for * the normal measurement mode. * @option_mode_1: first optional mode. Not all models have one * @option_mode_1_freq: option mode 1 sampling frequency * @option_mode_1_3db_freq: 3db cutoff frequency of the low pass filter for * the first option mode. * @option_mode_2: second optional mode. Not all chips have one * @option_mode_2_freq: option mode 2 sampling frequency * @option_mode_2_3db_freq: 3db cutoff frequency of the low pass filter for * the second option mode. * @mot_det_mult_xz: Bit wise multipliers to calculate the threshold * for motion detection in the x and z axis. * @mot_det_mult_y: Bit wise multipliers to calculate the threshold * for motion detection in the y axis. * * This structure is used to hold information about the functionality of a given * sca3000 variant. **/ struct sca3000_chip_info { … }; enum sca3000_variant { … }; /* * Note where option modes are not defined, the chip simply does not * support any. * Other chips in the sca3000 series use i2c and are not included here. * * Some of these devices are only listed in the family data sheet and * do not actually appear to be available. */ static const struct sca3000_chip_info sca3000_spi_chip_info_tbl[] = …; static int sca3000_write_reg(struct sca3000_state *st, u8 address, u8 val) { … } static int sca3000_read_data_short(struct sca3000_state *st, u8 reg_address_high, int len) { … } /** * sca3000_reg_lock_on() - test if the ctrl register lock is on * @st: Driver specific device instance data. * * Lock must be held. **/ static int sca3000_reg_lock_on(struct sca3000_state *st) { … } /** * __sca3000_unlock_reg_lock() - unlock the control registers * @st: Driver specific device instance data. * * Note the device does not appear to support doing this in a single transfer. * This should only ever be used as part of ctrl reg read. * Lock must be held before calling this */ static int __sca3000_unlock_reg_lock(struct sca3000_state *st) { … } /** * sca3000_write_ctrl_reg() - write to a lock protect ctrl register * @st: Driver specific device instance data. * @sel: selects which registers we wish to write to * @val: the value to be written * * Certain control registers are protected against overwriting by the lock * register and use a shared write address. This function allows writing of * these registers. * Lock must be held. */ static int sca3000_write_ctrl_reg(struct sca3000_state *st, u8 sel, uint8_t val) { … } /** * sca3000_read_ctrl_reg() - read from lock protected control register. * @st: Driver specific device instance data. * @ctrl_reg: Which ctrl register do we want to read. * * Lock must be held. */ static int sca3000_read_ctrl_reg(struct sca3000_state *st, u8 ctrl_reg) { … } /** * sca3000_print_rev() - sysfs interface to read the chip revision number * @indio_dev: Device instance specific generic IIO data. * Driver specific device instance data can be obtained via * iio_priv(indio_dev) */ static int sca3000_print_rev(struct iio_dev *indio_dev) { … } static ssize_t sca3000_show_available_3db_freqs(struct device *dev, struct device_attribute *attr, char *buf) { … } static IIO_DEVICE_ATTR(in_accel_filter_low_pass_3db_frequency_available, S_IRUGO, sca3000_show_available_3db_freqs, NULL, 0); static const struct iio_event_spec sca3000_event = …; /* * Note the hack in the number of bits to pretend we have 2 more than * we do in the fifo. */ #define SCA3000_CHAN(index, mod) … static const struct iio_event_spec sca3000_freefall_event_spec = …; static const struct iio_chan_spec sca3000_channels[] = …; static const struct iio_chan_spec sca3000_channels_with_temp[] = …; static u8 sca3000_addresses[3][3] = …; /** * __sca3000_get_base_freq() - obtain mode specific base frequency * @st: Private driver specific device instance specific state. * @info: chip type specific information. * @base_freq: Base frequency for the current measurement mode. * * lock must be held */ static inline int __sca3000_get_base_freq(struct sca3000_state *st, const struct sca3000_chip_info *info, int *base_freq) { … } /** * sca3000_read_raw_samp_freq() - read_raw handler for IIO_CHAN_INFO_SAMP_FREQ * @st: Private driver specific device instance specific state. * @val: The frequency read back. * * lock must be held **/ static int sca3000_read_raw_samp_freq(struct sca3000_state *st, int *val) { … } /** * sca3000_write_raw_samp_freq() - write_raw handler for IIO_CHAN_INFO_SAMP_FREQ * @st: Private driver specific device instance specific state. * @val: The frequency desired. * * lock must be held */ static int sca3000_write_raw_samp_freq(struct sca3000_state *st, int val) { … } static int sca3000_read_3db_freq(struct sca3000_state *st, int *val) { … } static int sca3000_write_3db_freq(struct sca3000_state *st, int val) { … } static int sca3000_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { … } static int sca3000_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { … } /** * sca3000_read_av_freq() - sysfs function to get available frequencies * @dev: Device structure for this device. * @attr: Description of the attribute. * @buf: Incoming string * * The later modes are only relevant to the ring buffer - and depend on current * mode. Note that data sheet gives rather wide tolerances for these so integer * division will give good enough answer and not all chips have them specified * at all. **/ static ssize_t sca3000_read_av_freq(struct device *dev, struct device_attribute *attr, char *buf) { … } /* * Should only really be registered if ring buffer support is compiled in. * Does no harm however and doing it right would add a fair bit of complexity */ static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(sca3000_read_av_freq); /* * sca3000_read_event_value() - query of a threshold or period */ static int sca3000_read_event_value(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, enum iio_event_type type, enum iio_event_direction dir, enum iio_event_info info, int *val, int *val2) { … } /** * sca3000_write_event_value() - control of threshold and period * @indio_dev: Device instance specific IIO information. * @chan: Description of the channel for which the event is being * configured. * @type: The type of event being configured, here magnitude rising * as everything else is read only. * @dir: Direction of the event (here rising) * @info: What information about the event are we configuring. * Here the threshold only. * @val: Integer part of the value being written.. * @val2: Non integer part of the value being written. Here always 0. */ static int sca3000_write_event_value(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, enum iio_event_type type, enum iio_event_direction dir, enum iio_event_info info, int val, int val2) { … } static struct attribute *sca3000_attributes[] = …; static const struct attribute_group sca3000_attribute_group = …; static int sca3000_read_data(struct sca3000_state *st, u8 reg_address_high, u8 *rx, int len) { … } /** * sca3000_ring_int_process() - ring specific interrupt handling. * @val: Value of the interrupt status register. * @indio_dev: Device instance specific IIO device structure. */ static void sca3000_ring_int_process(u8 val, struct iio_dev *indio_dev) { … } /** * sca3000_event_handler() - handling ring and non ring events * @irq: The irq being handled. * @private: struct iio_device pointer for the device. * * Ring related interrupt handler. Depending on event, push to * the ring buffer event chrdev or the event one. * * This function is complicated by the fact that the devices can signify ring * and non ring events via the same interrupt line and they can only * be distinguished via a read of the relevant status register. */ static irqreturn_t sca3000_event_handler(int irq, void *private) { … } /* * sca3000_read_event_config() what events are enabled */ static int sca3000_read_event_config(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, enum iio_event_type type, enum iio_event_direction dir) { … } static int sca3000_freefall_set_state(struct iio_dev *indio_dev, int state) { … } static int sca3000_motion_detect_set_state(struct iio_dev *indio_dev, int axis, int state) { … } /** * sca3000_write_event_config() - simple on off control for motion detector * @indio_dev: IIO device instance specific structure. Data specific to this * particular driver may be accessed via iio_priv(indio_dev). * @chan: Description of the channel whose event we are configuring. * @type: The type of event. * @dir: The direction of the event. * @state: Desired state of event being configured. * * This is a per axis control, but enabling any will result in the * motion detector unit being enabled. * N.B. enabling motion detector stops normal data acquisition. * There is a complexity in knowing which mode to return to when * this mode is disabled. Currently normal mode is assumed. **/ static int sca3000_write_event_config(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, enum iio_event_type type, enum iio_event_direction dir, int state) { … } static inline int __sca3000_hw_ring_state_set(struct iio_dev *indio_dev, bool state) { … } /** * sca3000_hw_ring_preenable() - hw ring buffer preenable function * @indio_dev: structure representing the IIO device. Device instance * specific state can be accessed via iio_priv(indio_dev). * * Very simple enable function as the chip will allows normal reads * during ring buffer operation so as long as it is indeed running * before we notify the core, the precise ordering does not matter. */ static int sca3000_hw_ring_preenable(struct iio_dev *indio_dev) { … } static int sca3000_hw_ring_postdisable(struct iio_dev *indio_dev) { … } static const struct iio_buffer_setup_ops sca3000_ring_setup_ops = …; /** * sca3000_clean_setup() - get the device into a predictable state * @st: Device instance specific private data structure * * Devices use flash memory to store many of the register values * and hence can come up in somewhat unpredictable states. * Hence reset everything on driver load. */ static int sca3000_clean_setup(struct sca3000_state *st) { … } static const struct iio_info sca3000_info = …; static int sca3000_probe(struct spi_device *spi) { … } static int sca3000_stop_all_interrupts(struct sca3000_state *st) { … } static void sca3000_remove(struct spi_device *spi) { … } static const struct spi_device_id sca3000_id[] = …; MODULE_DEVICE_TABLE(spi, sca3000_id); static struct spi_driver sca3000_driver = …; module_spi_driver(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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