// SPDX-License-Identifier: GPL-2.0-only /* * sca3000_core.c -- support VTI sca3000 series accelerometers via SPI * * Copyright (c) 2009 Jonathan Cameron * * See industrialio/accels/sca3000.h for comments. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define SCA3000_WRITE_REG(a) (((a) << 2) | 0x02) #define SCA3000_READ_REG(a) ((a) << 2) #define SCA3000_REG_REVID_ADDR 0x00 #define SCA3000_REG_REVID_MAJOR_MASK GENMASK(8, 4) #define SCA3000_REG_REVID_MINOR_MASK GENMASK(3, 0) #define SCA3000_REG_STATUS_ADDR 0x02 #define SCA3000_LOCKED BIT(5) #define SCA3000_EEPROM_CS_ERROR BIT(1) #define SCA3000_SPI_FRAME_ERROR BIT(0) /* All reads done using register decrement so no need to directly access LSBs */ #define SCA3000_REG_X_MSB_ADDR 0x05 #define SCA3000_REG_Y_MSB_ADDR 0x07 #define SCA3000_REG_Z_MSB_ADDR 0x09 #define SCA3000_REG_RING_OUT_ADDR 0x0f /* Temp read untested - the e05 doesn't have the sensor */ #define SCA3000_REG_TEMP_MSB_ADDR 0x13 #define SCA3000_REG_MODE_ADDR 0x14 #define SCA3000_MODE_PROT_MASK 0x28 #define SCA3000_REG_MODE_RING_BUF_ENABLE BIT(7) #define SCA3000_REG_MODE_RING_BUF_8BIT BIT(6) /* * 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 BIT(4) #define SCA3000_REG_MODE_MEAS_MODE_NORMAL 0x00 #define SCA3000_REG_MODE_MEAS_MODE_OP_1 0x01 #define SCA3000_REG_MODE_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_REG_MODE_MEAS_MODE_MOT_DET 0x03 #define SCA3000_REG_MODE_MODE_MASK 0x03 #define SCA3000_REG_BUF_COUNT_ADDR 0x15 #define SCA3000_REG_INT_STATUS_ADDR 0x16 #define SCA3000_REG_INT_STATUS_THREE_QUARTERS BIT(7) #define SCA3000_REG_INT_STATUS_HALF BIT(6) #define SCA3000_INT_STATUS_FREE_FALL BIT(3) #define SCA3000_INT_STATUS_Y_TRIGGER BIT(2) #define SCA3000_INT_STATUS_X_TRIGGER BIT(1) #define SCA3000_INT_STATUS_Z_TRIGGER BIT(0) /* Used to allow access to multiplexed registers */ #define SCA3000_REG_CTRL_SEL_ADDR 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_REG_OUT_CTRL_PROT_MASK 0xE0 #define SCA3000_REG_OUT_CTRL_BUF_X_EN 0x10 #define SCA3000_REG_OUT_CTRL_BUF_Y_EN 0x08 #define SCA3000_REG_OUT_CTRL_BUF_Z_EN 0x04 #define SCA3000_REG_OUT_CTRL_BUF_DIV_MASK 0x03 #define SCA3000_REG_OUT_CTRL_BUF_DIV_4 0x02 #define SCA3000_REG_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 BIT(0) #define SCA3000_MD_CTRL_OR_X BIT(1) #define SCA3000_MD_CTRL_OR_Z BIT(2) /* Currently unsupported */ #define SCA3000_MD_CTRL_AND_Y BIT(3) #define SCA3000_MD_CTRL_AND_X BIT(4) #define SCA3000_MD_CTRL_AND_Z BIT(5) /* * Some control registers of complex access methods requiring this register to * be used to remove a lock. */ #define SCA3000_REG_UNLOCK_ADDR 0x1e #define SCA3000_REG_INT_MASK_ADDR 0x21 #define SCA3000_REG_INT_MASK_PROT_MASK 0x1C #define SCA3000_REG_INT_MASK_RING_THREE_QUARTER BIT(7) #define SCA3000_REG_INT_MASK_RING_HALF BIT(6) #define SCA3000_REG_INT_MASK_ALL_INTS 0x02 #define SCA3000_REG_INT_MASK_ACTIVE_HIGH 0x01 #define SCA3000_REG_INT_MASK_ACTIVE_LOW 0x00 /* Values of multiplexed registers (write to ctrl_data after select) */ #define SCA3000_REG_CTRL_DATA_ADDR 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 * @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 spi_device *us; const struct sca3000_chip_info *info; s64 last_timestamp; int mo_det_use_count; struct mutex lock; /* Can these share a cacheline ? */ u8 rx[384] ____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 * @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. * @mod_det_mult_xz: Bit wise multipliers to calculate the threshold * for motion detection in the x and z axis. * @mod_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 { unsigned int scale; bool temp_output; int measurement_mode_freq; int measurement_mode_3db_freq; int option_mode_1; int option_mode_1_freq; int option_mode_1_3db_freq; int option_mode_2; int option_mode_2_freq; int option_mode_2_3db_freq; int mot_det_mult_xz[6]; int mot_det_mult_y[7]; }; enum sca3000_variant { d01, e02, e04, e05, }; /* * 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[] = { [d01] = { .scale = 7357, .temp_output = true, .measurement_mode_freq = 250, .measurement_mode_3db_freq = 45, .option_mode_1 = SCA3000_OP_MODE_BYPASS, .option_mode_1_freq = 250, .option_mode_1_3db_freq = 70, .mot_det_mult_xz = {50, 100, 200, 350, 650, 1300}, .mot_det_mult_y = {50, 100, 150, 250, 450, 850, 1750}, }, [e02] = { .scale = 9810, .measurement_mode_freq = 125, .measurement_mode_3db_freq = 40, .option_mode_1 = SCA3000_OP_MODE_NARROW, .option_mode_1_freq = 63, .option_mode_1_3db_freq = 11, .mot_det_mult_xz = {100, 150, 300, 550, 1050, 2050}, .mot_det_mult_y = {50, 100, 200, 350, 700, 1350, 2700}, }, [e04] = { .scale = 19620, .measurement_mode_freq = 100, .measurement_mode_3db_freq = 38, .option_mode_1 = SCA3000_OP_MODE_NARROW, .option_mode_1_freq = 50, .option_mode_1_3db_freq = 9, .option_mode_2 = SCA3000_OP_MODE_WIDE, .option_mode_2_freq = 400, .option_mode_2_3db_freq = 70, .mot_det_mult_xz = {200, 300, 600, 1100, 2100, 4100}, .mot_det_mult_y = {100, 200, 400, 7000, 1400, 2700, 54000}, }, [e05] = { .scale = 61313, .measurement_mode_freq = 200, .measurement_mode_3db_freq = 60, .option_mode_1 = SCA3000_OP_MODE_NARROW, .option_mode_1_freq = 50, .option_mode_1_3db_freq = 9, .option_mode_2 = SCA3000_OP_MODE_WIDE, .option_mode_2_freq = 400, .option_mode_2_3db_freq = 75, .mot_det_mult_xz = {600, 900, 1700, 3200, 6100, 11900}, .mot_det_mult_y = {300, 600, 1200, 2000, 4100, 7800, 15600}, }, }; static int sca3000_write_reg(struct sca3000_state *st, u8 address, u8 val) { st->tx[0] = SCA3000_WRITE_REG(address); st->tx[1] = val; return spi_write(st->us, st->tx, 2); } static int sca3000_read_data_short(struct sca3000_state *st, u8 reg_address_high, int len) { struct spi_transfer xfer[2] = { { .len = 1, .tx_buf = st->tx, }, { .len = len, .rx_buf = st->rx, } }; st->tx[0] = SCA3000_READ_REG(reg_address_high); return spi_sync_transfer(st->us, xfer, ARRAY_SIZE(xfer)); } /** * 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) { int ret; ret = sca3000_read_data_short(st, SCA3000_REG_STATUS_ADDR, 1); if (ret < 0) return ret; return !(st->rx[0] & SCA3000_LOCKED); } /** * __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) { struct spi_transfer xfer[3] = { { .len = 2, .cs_change = 1, .tx_buf = st->tx, }, { .len = 2, .cs_change = 1, .tx_buf = st->tx + 2, }, { .len = 2, .tx_buf = st->tx + 4, }, }; st->tx[0] = SCA3000_WRITE_REG(SCA3000_REG_UNLOCK_ADDR); st->tx[1] = 0x00; st->tx[2] = SCA3000_WRITE_REG(SCA3000_REG_UNLOCK_ADDR); st->tx[3] = 0x50; st->tx[4] = SCA3000_WRITE_REG(SCA3000_REG_UNLOCK_ADDR); st->tx[5] = 0xA0; return spi_sync_transfer(st->us, xfer, ARRAY_SIZE(xfer)); } /** * 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) { int ret; ret = sca3000_reg_lock_on(st); if (ret < 0) goto error_ret; if (ret) { ret = __sca3000_unlock_reg_lock(st); if (ret) goto error_ret; } /* Set the control select register */ ret = sca3000_write_reg(st, SCA3000_REG_CTRL_SEL_ADDR, sel); if (ret) goto error_ret; /* Write the actual value into the register */ ret = sca3000_write_reg(st, SCA3000_REG_CTRL_DATA_ADDR, val); error_ret: return ret; } /** * 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) { int ret; ret = sca3000_reg_lock_on(st); if (ret < 0) goto error_ret; if (ret) { ret = __sca3000_unlock_reg_lock(st); if (ret) goto error_ret; } /* Set the control select register */ ret = sca3000_write_reg(st, SCA3000_REG_CTRL_SEL_ADDR, ctrl_reg); if (ret) goto error_ret; ret = sca3000_read_data_short(st, SCA3000_REG_CTRL_DATA_ADDR, 1); if (ret) goto error_ret; return st->rx[0]; error_ret: return ret; } /** * sca3000_show_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 * via iio_priv(indio_dev) */ static int sca3000_print_rev(struct iio_dev *indio_dev) { int ret; struct sca3000_state *st = iio_priv(indio_dev); mutex_lock(&st->lock); ret = sca3000_read_data_short(st, SCA3000_REG_REVID_ADDR, 1); if (ret < 0) goto error_ret; dev_info(&indio_dev->dev, "sca3000 revision major=%lu, minor=%lu\n", st->rx[0] & SCA3000_REG_REVID_MAJOR_MASK, st->rx[0] & SCA3000_REG_REVID_MINOR_MASK); error_ret: mutex_unlock(&st->lock); return ret; } static ssize_t sca3000_show_available_3db_freqs(struct device *dev, struct device_attribute *attr, char *buf) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct sca3000_state *st = iio_priv(indio_dev); int len; len = sprintf(buf, "%d", st->info->measurement_mode_3db_freq); if (st->info->option_mode_1) len += sprintf(buf + len, " %d", st->info->option_mode_1_3db_freq); if (st->info->option_mode_2) len += sprintf(buf + len, " %d", st->info->option_mode_2_3db_freq); len += sprintf(buf + len, "\n"); return len; } 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 = { .type = IIO_EV_TYPE_MAG, .dir = IIO_EV_DIR_RISING, .mask_separate = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_ENABLE), }; /* * 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) \ { \ .type = IIO_ACCEL, \ .modified = 1, \ .channel2 = mod, \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |\ BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),\ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),\ .address = index, \ .scan_index = index, \ .scan_type = { \ .sign = 's', \ .realbits = 13, \ .storagebits = 16, \ .shift = 3, \ .endianness = IIO_BE, \ }, \ .event_spec = &sca3000_event, \ .num_event_specs = 1, \ } static const struct iio_event_spec sca3000_freefall_event_spec = { .type = IIO_EV_TYPE_MAG, .dir = IIO_EV_DIR_FALLING, .mask_separate = BIT(IIO_EV_INFO_ENABLE) | BIT(IIO_EV_INFO_PERIOD), }; static const struct iio_chan_spec sca3000_channels[] = { SCA3000_CHAN(0, IIO_MOD_X), SCA3000_CHAN(1, IIO_MOD_Y), SCA3000_CHAN(2, IIO_MOD_Z), { .type = IIO_ACCEL, .modified = 1, .channel2 = IIO_MOD_X_AND_Y_AND_Z, .scan_index = -1, /* Fake channel */ .event_spec = &sca3000_freefall_event_spec, .num_event_specs = 1, }, }; static const struct iio_chan_spec sca3000_channels_with_temp[] = { SCA3000_CHAN(0, IIO_MOD_X), SCA3000_CHAN(1, IIO_MOD_Y), SCA3000_CHAN(2, IIO_MOD_Z), { .type = IIO_TEMP, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET), /* No buffer support */ .scan_index = -1, }, { .type = IIO_ACCEL, .modified = 1, .channel2 = IIO_MOD_X_AND_Y_AND_Z, .scan_index = -1, /* Fake channel */ .event_spec = &sca3000_freefall_event_spec, .num_event_specs = 1, }, }; static u8 sca3000_addresses[3][3] = { [0] = {SCA3000_REG_X_MSB_ADDR, SCA3000_REG_CTRL_SEL_MD_X_TH, SCA3000_MD_CTRL_OR_X}, [1] = {SCA3000_REG_Y_MSB_ADDR, SCA3000_REG_CTRL_SEL_MD_Y_TH, SCA3000_MD_CTRL_OR_Y}, [2] = {SCA3000_REG_Z_MSB_ADDR, SCA3000_REG_CTRL_SEL_MD_Z_TH, SCA3000_MD_CTRL_OR_Z}, }; /** * __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) { int ret; ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1); if (ret) goto error_ret; switch (SCA3000_REG_MODE_MODE_MASK & st->rx[0]) { case SCA3000_REG_MODE_MEAS_MODE_NORMAL: *base_freq = info->measurement_mode_freq; break; case SCA3000_REG_MODE_MEAS_MODE_OP_1: *base_freq = info->option_mode_1_freq; break; case SCA3000_REG_MODE_MEAS_MODE_OP_2: *base_freq = info->option_mode_2_freq; break; default: ret = -EINVAL; } error_ret: return ret; } /** * 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) { int ret; ret = __sca3000_get_base_freq(st, st->info, val); if (ret) return ret; ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL); if (ret < 0) return ret; if (*val > 0) { ret &= SCA3000_REG_OUT_CTRL_BUF_DIV_MASK; switch (ret) { case SCA3000_REG_OUT_CTRL_BUF_DIV_2: *val /= 2; break; case SCA3000_REG_OUT_CTRL_BUF_DIV_4: *val /= 4; break; } } return 0; } /** * 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) { int ret, base_freq, ctrlval; ret = __sca3000_get_base_freq(st, st->info, &base_freq); if (ret) return ret; ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL); if (ret < 0) return ret; ctrlval = ret & ~SCA3000_REG_OUT_CTRL_BUF_DIV_MASK; if (val == base_freq / 2) ctrlval |= SCA3000_REG_OUT_CTRL_BUF_DIV_2; if (val == base_freq / 4) ctrlval |= SCA3000_REG_OUT_CTRL_BUF_DIV_4; else if (val != base_freq) return -EINVAL; return sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL, ctrlval); } static int sca3000_read_3db_freq(struct sca3000_state *st, int *val) { int ret; ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1); if (ret) return ret; /* mask bottom 2 bits - only ones that are relevant */ st->rx[0] &= SCA3000_REG_MODE_MODE_MASK; switch (st->rx[0]) { case SCA3000_REG_MODE_MEAS_MODE_NORMAL: *val = st->info->measurement_mode_3db_freq; return IIO_VAL_INT; case SCA3000_REG_MODE_MEAS_MODE_MOT_DET: return -EBUSY; case SCA3000_REG_MODE_MEAS_MODE_OP_1: *val = st->info->option_mode_1_3db_freq; return IIO_VAL_INT; case SCA3000_REG_MODE_MEAS_MODE_OP_2: *val = st->info->option_mode_2_3db_freq; return IIO_VAL_INT; default: return -EINVAL; } } static int sca3000_write_3db_freq(struct sca3000_state *st, int val) { int ret; int mode; if (val == st->info->measurement_mode_3db_freq) mode = SCA3000_REG_MODE_MEAS_MODE_NORMAL; else if (st->info->option_mode_1 && (val == st->info->option_mode_1_3db_freq)) mode = SCA3000_REG_MODE_MEAS_MODE_OP_1; else if (st->info->option_mode_2 && (val == st->info->option_mode_2_3db_freq)) mode = SCA3000_REG_MODE_MEAS_MODE_OP_2; else return -EINVAL; ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1); if (ret) return ret; st->rx[0] &= ~SCA3000_REG_MODE_MODE_MASK; st->rx[0] |= (mode & SCA3000_REG_MODE_MODE_MASK); return sca3000_write_reg(st, SCA3000_REG_MODE_ADDR, st->rx[0]); } static int sca3000_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct sca3000_state *st = iio_priv(indio_dev); int ret; u8 address; switch (mask) { case IIO_CHAN_INFO_RAW: mutex_lock(&st->lock); if (chan->type == IIO_ACCEL) { if (st->mo_det_use_count) { mutex_unlock(&st->lock); return -EBUSY; } address = sca3000_addresses[chan->address][0]; ret = sca3000_read_data_short(st, address, 2); if (ret < 0) { mutex_unlock(&st->lock); return ret; } *val = (be16_to_cpup((__be16 *)st->rx) >> 3) & 0x1FFF; *val = ((*val) << (sizeof(*val) * 8 - 13)) >> (sizeof(*val) * 8 - 13); } else { /* get the temperature when available */ ret = sca3000_read_data_short(st, SCA3000_REG_TEMP_MSB_ADDR, 2); if (ret < 0) { mutex_unlock(&st->lock); return ret; } *val = ((st->rx[0] & 0x3F) << 3) | ((st->rx[1] & 0xE0) >> 5); } mutex_unlock(&st->lock); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: *val = 0; if (chan->type == IIO_ACCEL) *val2 = st->info->scale; else /* temperature */ *val2 = 555556; return IIO_VAL_INT_PLUS_MICRO; case IIO_CHAN_INFO_OFFSET: *val = -214; *val2 = 600000; return IIO_VAL_INT_PLUS_MICRO; case IIO_CHAN_INFO_SAMP_FREQ: mutex_lock(&st->lock); ret = sca3000_read_raw_samp_freq(st, val); mutex_unlock(&st->lock); return ret ? ret : IIO_VAL_INT; case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: mutex_lock(&st->lock); ret = sca3000_read_3db_freq(st, val); mutex_unlock(&st->lock); return ret; default: return -EINVAL; } } static int sca3000_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { struct sca3000_state *st = iio_priv(indio_dev); int ret; switch (mask) { case IIO_CHAN_INFO_SAMP_FREQ: if (val2) return -EINVAL; mutex_lock(&st->lock); ret = sca3000_write_raw_samp_freq(st, val); mutex_unlock(&st->lock); return ret; case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: if (val2) return -EINVAL; mutex_lock(&st->lock); ret = sca3000_write_3db_freq(st, val); mutex_unlock(&st->lock); return ret; default: return -EINVAL; } return ret; } /** * 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) { struct iio_dev *indio_dev = dev_to_iio_dev(dev); struct sca3000_state *st = iio_priv(indio_dev); int len = 0, ret, val; mutex_lock(&st->lock); ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1); val = st->rx[0]; mutex_unlock(&st->lock); if (ret) goto error_ret; switch (val & SCA3000_REG_MODE_MODE_MASK) { case SCA3000_REG_MODE_MEAS_MODE_NORMAL: len += sprintf(buf + len, "%d %d %d\n", st->info->measurement_mode_freq, st->info->measurement_mode_freq / 2, st->info->measurement_mode_freq / 4); break; case SCA3000_REG_MODE_MEAS_MODE_OP_1: len += sprintf(buf + len, "%d %d %d\n", st->info->option_mode_1_freq, st->info->option_mode_1_freq / 2, st->info->option_mode_1_freq / 4); break; case SCA3000_REG_MODE_MEAS_MODE_OP_2: len += sprintf(buf + len, "%d %d %d\n", st->info->option_mode_2_freq, st->info->option_mode_2_freq / 2, st->info->option_mode_2_freq / 4); break; } return len; error_ret: return ret; } /* * 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) { struct sca3000_state *st = iio_priv(indio_dev); long ret; int i; switch (info) { case IIO_EV_INFO_VALUE: mutex_lock(&st->lock); ret = sca3000_read_ctrl_reg(st, sca3000_addresses[chan->address][1]); mutex_unlock(&st->lock); if (ret < 0) return ret; *val = 0; if (chan->channel2 == IIO_MOD_Y) for_each_set_bit(i, &ret, ARRAY_SIZE(st->info->mot_det_mult_y)) *val += st->info->mot_det_mult_y[i]; else for_each_set_bit(i, &ret, ARRAY_SIZE(st->info->mot_det_mult_xz)) *val += st->info->mot_det_mult_xz[i]; return IIO_VAL_INT; case IIO_EV_INFO_PERIOD: *val = 0; *val2 = 226000; return IIO_VAL_INT_PLUS_MICRO; default: return -EINVAL; } } /** * sca3000_write_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) { struct sca3000_state *st = iio_priv(indio_dev); int ret; int i; u8 nonlinear = 0; if (chan->channel2 == IIO_MOD_Y) { i = ARRAY_SIZE(st->info->mot_det_mult_y); while (i > 0) if (val >= st->info->mot_det_mult_y[--i]) { nonlinear |= (1 << i); val -= st->info->mot_det_mult_y[i]; } } else { i = ARRAY_SIZE(st->info->mot_det_mult_xz); while (i > 0) if (val >= st->info->mot_det_mult_xz[--i]) { nonlinear |= (1 << i); val -= st->info->mot_det_mult_xz[i]; } } mutex_lock(&st->lock); ret = sca3000_write_ctrl_reg(st, sca3000_addresses[chan->address][1], nonlinear); mutex_unlock(&st->lock); return ret; } static struct attribute *sca3000_attributes[] = { &iio_dev_attr_in_accel_filter_low_pass_3db_frequency_available.dev_attr.attr, &iio_dev_attr_sampling_frequency_available.dev_attr.attr, NULL, }; static const struct attribute_group sca3000_attribute_group = { .attrs = sca3000_attributes, }; static int sca3000_read_data(struct sca3000_state *st, u8 reg_address_high, u8 *rx, int len) { int ret; struct spi_transfer xfer[2] = { { .len = 1, .tx_buf = st->tx, }, { .len = len, .rx_buf = rx, } }; st->tx[0] = SCA3000_READ_REG(reg_address_high); ret = spi_sync_transfer(st->us, xfer, ARRAY_SIZE(xfer)); if (ret) { dev_err(&st->us->dev, "problem reading register\n"); return ret; } return 0; } /** * 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) { struct sca3000_state *st = iio_priv(indio_dev); int ret, i, num_available; mutex_lock(&st->lock); if (val & SCA3000_REG_INT_STATUS_HALF) { ret = sca3000_read_data_short(st, SCA3000_REG_BUF_COUNT_ADDR, 1); if (ret) goto error_ret; num_available = st->rx[0]; /* * num_available is the total number of samples available * i.e. number of time points * number of channels. */ ret = sca3000_read_data(st, SCA3000_REG_RING_OUT_ADDR, st->rx, num_available * 2); if (ret) goto error_ret; for (i = 0; i < num_available / 3; i++) { /* * Dirty hack to cover for 11 bit in fifo, 13 bit * direct reading. * * In theory the bottom two bits are undefined. * In reality they appear to always be 0. */ iio_push_to_buffers(indio_dev, st->rx + i * 3 * 2); } } error_ret: mutex_unlock(&st->lock); } /** * 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) { struct iio_dev *indio_dev = private; struct sca3000_state *st = iio_priv(indio_dev); int ret, val; s64 last_timestamp = iio_get_time_ns(indio_dev); /* * Could lead if badly timed to an extra read of status reg, * but ensures no interrupt is missed. */ mutex_lock(&st->lock); ret = sca3000_read_data_short(st, SCA3000_REG_INT_STATUS_ADDR, 1); val = st->rx[0]; mutex_unlock(&st->lock); if (ret) goto done; sca3000_ring_int_process(val, indio_dev); if (val & SCA3000_INT_STATUS_FREE_FALL) iio_push_event(indio_dev, IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, IIO_MOD_X_AND_Y_AND_Z, IIO_EV_TYPE_MAG, IIO_EV_DIR_FALLING), last_timestamp); if (val & SCA3000_INT_STATUS_Y_TRIGGER) iio_push_event(indio_dev, IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, IIO_MOD_Y, IIO_EV_TYPE_MAG, IIO_EV_DIR_RISING), last_timestamp); if (val & SCA3000_INT_STATUS_X_TRIGGER) iio_push_event(indio_dev, IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, IIO_MOD_X, IIO_EV_TYPE_MAG, IIO_EV_DIR_RISING), last_timestamp); if (val & SCA3000_INT_STATUS_Z_TRIGGER) iio_push_event(indio_dev, IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, IIO_MOD_Z, IIO_EV_TYPE_MAG, IIO_EV_DIR_RISING), last_timestamp); done: return IRQ_HANDLED; } /** * 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) { struct sca3000_state *st = iio_priv(indio_dev); int ret; /* read current value of mode register */ mutex_lock(&st->lock); ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1); if (ret) goto error_ret; switch (chan->channel2) { case IIO_MOD_X_AND_Y_AND_Z: ret = !!(st->rx[0] & SCA3000_REG_MODE_FREE_FALL_DETECT); break; case IIO_MOD_X: case IIO_MOD_Y: case IIO_MOD_Z: /* * Motion detection mode cannot run at the same time as * acceleration data being read. */ if ((st->rx[0] & SCA3000_REG_MODE_MODE_MASK) != SCA3000_REG_MODE_MEAS_MODE_MOT_DET) { ret = 0; } else { ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL); if (ret < 0) goto error_ret; /* only supporting logical or's for now */ ret = !!(ret & sca3000_addresses[chan->address][2]); } break; default: ret = -EINVAL; } error_ret: mutex_unlock(&st->lock); return ret; } static int sca3000_freefall_set_state(struct iio_dev *indio_dev, int state) { struct sca3000_state *st = iio_priv(indio_dev); int ret; /* read current value of mode register */ ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1); if (ret) return ret; /* if off and should be on */ if (state && !(st->rx[0] & SCA3000_REG_MODE_FREE_FALL_DETECT)) return sca3000_write_reg(st, SCA3000_REG_MODE_ADDR, st->rx[0] | SCA3000_REG_MODE_FREE_FALL_DETECT); /* if on and should be off */ else if (!state && (st->rx[0] & SCA3000_REG_MODE_FREE_FALL_DETECT)) return sca3000_write_reg(st, SCA3000_REG_MODE_ADDR, st->rx[0] & ~SCA3000_REG_MODE_FREE_FALL_DETECT); else return 0; } static int sca3000_motion_detect_set_state(struct iio_dev *indio_dev, int axis, int state) { struct sca3000_state *st = iio_priv(indio_dev); int ret, ctrlval; /* * First read the motion detector config to find out if * this axis is on */ ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL); if (ret < 0) return ret; ctrlval = ret; /* if off and should be on */ if (state && !(ctrlval & sca3000_addresses[axis][2])) { ret = sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL, ctrlval | sca3000_addresses[axis][2]); if (ret) return ret; st->mo_det_use_count++; } else if (!state && (ctrlval & sca3000_addresses[axis][2])) { ret = sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL, ctrlval & ~(sca3000_addresses[axis][2])); if (ret) return ret; st->mo_det_use_count--; } /* read current value of mode register */ ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1); if (ret) return ret; /* if off and should be on */ if ((st->mo_det_use_count) && ((st->rx[0] & SCA3000_REG_MODE_MODE_MASK) != SCA3000_REG_MODE_MEAS_MODE_MOT_DET)) return sca3000_write_reg(st, SCA3000_REG_MODE_ADDR, (st->rx[0] & ~SCA3000_REG_MODE_MODE_MASK) | SCA3000_REG_MODE_MEAS_MODE_MOT_DET); /* if on and should be off */ else if (!(st->mo_det_use_count) && ((st->rx[0] & SCA3000_REG_MODE_MODE_MASK) == SCA3000_REG_MODE_MEAS_MODE_MOT_DET)) return sca3000_write_reg(st, SCA3000_REG_MODE_ADDR, st->rx[0] & SCA3000_REG_MODE_MODE_MASK); else return 0; } /** * 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) { struct sca3000_state *st = iio_priv(indio_dev); int ret; mutex_lock(&st->lock); switch (chan->channel2) { case IIO_MOD_X_AND_Y_AND_Z: ret = sca3000_freefall_set_state(indio_dev, state); break; case IIO_MOD_X: case IIO_MOD_Y: case IIO_MOD_Z: ret = sca3000_motion_detect_set_state(indio_dev, chan->address, state); break; default: ret = -EINVAL; break; } mutex_unlock(&st->lock); return ret; } static int sca3000_configure_ring(struct iio_dev *indio_dev) { struct iio_buffer *buffer; buffer = devm_iio_kfifo_allocate(&indio_dev->dev); if (!buffer) return -ENOMEM; iio_device_attach_buffer(indio_dev, buffer); indio_dev->modes |= INDIO_BUFFER_SOFTWARE; return 0; } static inline int __sca3000_hw_ring_state_set(struct iio_dev *indio_dev, bool state) { struct sca3000_state *st = iio_priv(indio_dev); int ret; mutex_lock(&st->lock); ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1); if (ret) goto error_ret; if (state) { dev_info(&indio_dev->dev, "supposedly enabling ring buffer\n"); ret = sca3000_write_reg(st, SCA3000_REG_MODE_ADDR, (st->rx[0] | SCA3000_REG_MODE_RING_BUF_ENABLE)); } else ret = sca3000_write_reg(st, SCA3000_REG_MODE_ADDR, (st->rx[0] & ~SCA3000_REG_MODE_RING_BUF_ENABLE)); error_ret: mutex_unlock(&st->lock); return ret; } /** * 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) { int ret; struct sca3000_state *st = iio_priv(indio_dev); mutex_lock(&st->lock); /* Enable the 50% full interrupt */ ret = sca3000_read_data_short(st, SCA3000_REG_INT_MASK_ADDR, 1); if (ret) goto error_unlock; ret = sca3000_write_reg(st, SCA3000_REG_INT_MASK_ADDR, st->rx[0] | SCA3000_REG_INT_MASK_RING_HALF); if (ret) goto error_unlock; mutex_unlock(&st->lock); return __sca3000_hw_ring_state_set(indio_dev, 1); error_unlock: mutex_unlock(&st->lock); return ret; } static int sca3000_hw_ring_postdisable(struct iio_dev *indio_dev) { int ret; struct sca3000_state *st = iio_priv(indio_dev); ret = __sca3000_hw_ring_state_set(indio_dev, 0); if (ret) return ret; /* Disable the 50% full interrupt */ mutex_lock(&st->lock); ret = sca3000_read_data_short(st, SCA3000_REG_INT_MASK_ADDR, 1); if (ret) goto unlock; ret = sca3000_write_reg(st, SCA3000_REG_INT_MASK_ADDR, st->rx[0] & ~SCA3000_REG_INT_MASK_RING_HALF); unlock: mutex_unlock(&st->lock); return ret; } static const struct iio_buffer_setup_ops sca3000_ring_setup_ops = { .preenable = &sca3000_hw_ring_preenable, .postdisable = &sca3000_hw_ring_postdisable, }; /** * 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) { int ret; mutex_lock(&st->lock); /* Ensure all interrupts have been acknowledged */ ret = sca3000_read_data_short(st, SCA3000_REG_INT_STATUS_ADDR, 1); if (ret) goto error_ret; /* Turn off all motion detection channels */ ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL); if (ret < 0) goto error_ret; ret = sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL, ret & SCA3000_MD_CTRL_PROT_MASK); if (ret) goto error_ret; /* Disable ring buffer */ ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL); if (ret < 0) goto error_ret; ret = sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL, (ret & SCA3000_REG_OUT_CTRL_PROT_MASK) | SCA3000_REG_OUT_CTRL_BUF_X_EN | SCA3000_REG_OUT_CTRL_BUF_Y_EN | SCA3000_REG_OUT_CTRL_BUF_Z_EN | SCA3000_REG_OUT_CTRL_BUF_DIV_4); if (ret) goto error_ret; /* Enable interrupts, relevant to mode and set up as active low */ ret = sca3000_read_data_short(st, SCA3000_REG_INT_MASK_ADDR, 1); if (ret) goto error_ret; ret = sca3000_write_reg(st, SCA3000_REG_INT_MASK_ADDR, (ret & SCA3000_REG_INT_MASK_PROT_MASK) | SCA3000_REG_INT_MASK_ACTIVE_LOW); if (ret) goto error_ret; /* * Select normal measurement mode, free fall off, ring off * Ring in 12 bit mode - it is fine to overwrite reserved bits 3,5 * as that occurs in one of the example on the datasheet */ ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1); if (ret) goto error_ret; ret = sca3000_write_reg(st, SCA3000_REG_MODE_ADDR, (st->rx[0] & SCA3000_MODE_PROT_MASK)); error_ret: mutex_unlock(&st->lock); return ret; } static const struct iio_info sca3000_info = { .attrs = &sca3000_attribute_group, .read_raw = &sca3000_read_raw, .write_raw = &sca3000_write_raw, .read_event_value = &sca3000_read_event_value, .write_event_value = &sca3000_write_event_value, .read_event_config = &sca3000_read_event_config, .write_event_config = &sca3000_write_event_config, }; static int sca3000_probe(struct spi_device *spi) { int ret; struct sca3000_state *st; struct iio_dev *indio_dev; indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); if (!indio_dev) return -ENOMEM; st = iio_priv(indio_dev); spi_set_drvdata(spi, indio_dev); st->us = spi; mutex_init(&st->lock); st->info = &sca3000_spi_chip_info_tbl[spi_get_device_id(spi) ->driver_data]; indio_dev->name = spi_get_device_id(spi)->name; indio_dev->info = &sca3000_info; if (st->info->temp_output) { indio_dev->channels = sca3000_channels_with_temp; indio_dev->num_channels = ARRAY_SIZE(sca3000_channels_with_temp); } else { indio_dev->channels = sca3000_channels; indio_dev->num_channels = ARRAY_SIZE(sca3000_channels); } indio_dev->modes = INDIO_DIRECT_MODE; ret = sca3000_configure_ring(indio_dev); if (ret) return ret; if (spi->irq) { ret = request_threaded_irq(spi->irq, NULL, &sca3000_event_handler, IRQF_TRIGGER_FALLING | IRQF_ONESHOT, "sca3000", indio_dev); if (ret) return ret; } indio_dev->setup_ops = &sca3000_ring_setup_ops; ret = sca3000_clean_setup(st); if (ret) goto error_free_irq; ret = sca3000_print_rev(indio_dev); if (ret) goto error_free_irq; return iio_device_register(indio_dev); error_free_irq: if (spi->irq) free_irq(spi->irq, indio_dev); return ret; } static int sca3000_stop_all_interrupts(struct sca3000_state *st) { int ret; mutex_lock(&st->lock); ret = sca3000_read_data_short(st, SCA3000_REG_INT_MASK_ADDR, 1); if (ret) goto error_ret; ret = sca3000_write_reg(st, SCA3000_REG_INT_MASK_ADDR, (st->rx[0] & ~(SCA3000_REG_INT_MASK_RING_THREE_QUARTER | SCA3000_REG_INT_MASK_RING_HALF | SCA3000_REG_INT_MASK_ALL_INTS))); error_ret: mutex_unlock(&st->lock); return ret; } static int sca3000_remove(struct spi_device *spi) { struct iio_dev *indio_dev = spi_get_drvdata(spi); struct sca3000_state *st = iio_priv(indio_dev); iio_device_unregister(indio_dev); /* Must ensure no interrupts can be generated after this! */ sca3000_stop_all_interrupts(st); if (spi->irq) free_irq(spi->irq, indio_dev); return 0; } static const struct spi_device_id sca3000_id[] = { {"sca3000_d01", d01}, {"sca3000_e02", e02}, {"sca3000_e04", e04}, {"sca3000_e05", e05}, {} }; MODULE_DEVICE_TABLE(spi, sca3000_id); static struct spi_driver sca3000_driver = { .driver = { .name = "sca3000", }, .probe = sca3000_probe, .remove = sca3000_remove, .id_table = sca3000_id, }; module_spi_driver(sca3000_driver); MODULE_AUTHOR("Jonathan Cameron "); MODULE_DESCRIPTION("VTI SCA3000 Series Accelerometers SPI driver"); MODULE_LICENSE("GPL v2");