// SPDX-License-Identifier: GPL-2.0-only /* * Murata SCA3300 3-axis industrial accelerometer * * Copyright (c) 2021 Vaisala Oyj. All rights reserved. */ #include #include #include #include #include #include #include #include #include #include #include #include #define SCA3300_ALIAS "sca3300" #define SCA3300_CRC8_POLYNOMIAL 0x1d /* Device mode register */ #define SCA3300_REG_MODE 0xd #define SCA3300_MODE_SW_RESET 0x20 /* Last register in map */ #define SCA3300_REG_SELBANK 0x1f /* Device status and mask */ #define SCA3300_REG_STATUS 0x6 #define SCA3300_STATUS_MASK GENMASK(8, 0) /* Device ID */ #define SCA3300_REG_WHOAMI 0x10 #define SCA3300_WHOAMI_ID 0x51 /* Device return status and mask */ #define SCA3300_VALUE_RS_ERROR 0x3 #define SCA3300_MASK_RS_STATUS GENMASK(1, 0) enum sca3300_scan_indexes { SCA3300_ACC_X = 0, SCA3300_ACC_Y, SCA3300_ACC_Z, SCA3300_TEMP, SCA3300_TIMESTAMP, }; #define SCA3300_ACCEL_CHANNEL(index, reg, axis) { \ .type = IIO_ACCEL, \ .address = reg, \ .modified = 1, \ .channel2 = IIO_MOD_##axis, \ .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_type_available = \ BIT(IIO_CHAN_INFO_SCALE) | \ BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), \ .scan_index = index, \ .scan_type = { \ .sign = 's', \ .realbits = 16, \ .storagebits = 16, \ .endianness = IIO_CPU, \ }, \ } static const struct iio_chan_spec sca3300_channels[] = { SCA3300_ACCEL_CHANNEL(SCA3300_ACC_X, 0x1, X), SCA3300_ACCEL_CHANNEL(SCA3300_ACC_Y, 0x2, Y), SCA3300_ACCEL_CHANNEL(SCA3300_ACC_Z, 0x3, Z), { .type = IIO_TEMP, .address = 0x5, .scan_index = SCA3300_TEMP, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), .scan_type = { .sign = 's', .realbits = 16, .storagebits = 16, .endianness = IIO_CPU, }, }, IIO_CHAN_SOFT_TIMESTAMP(4), }; static const int sca3300_lp_freq[] = {70, 70, 70, 10}; static const int sca3300_accel_scale[][2] = {{0, 370}, {0, 741}, {0, 185}, {0, 185}}; static const unsigned long sca3300_scan_masks[] = { BIT(SCA3300_ACC_X) | BIT(SCA3300_ACC_Y) | BIT(SCA3300_ACC_Z) | BIT(SCA3300_TEMP), 0 }; /** * struct sca3300_data - device data * @spi: SPI device structure * @lock: Data buffer lock * @scan: Triggered buffer. Four channel 16-bit data + 64-bit timestamp * @txbuf: Transmit buffer * @rxbuf: Receive buffer */ struct sca3300_data { struct spi_device *spi; struct mutex lock; struct { s16 channels[4]; s64 ts __aligned(sizeof(s64)); } scan; u8 txbuf[4] __aligned(IIO_DMA_MINALIGN); u8 rxbuf[4]; }; DECLARE_CRC8_TABLE(sca3300_crc_table); static int sca3300_transfer(struct sca3300_data *sca_data, int *val) { /* Consecutive requests min. 10 us delay (Datasheet section 5.1.2) */ struct spi_delay delay = { .value = 10, .unit = SPI_DELAY_UNIT_USECS }; int32_t ret; int rs; u8 crc; struct spi_transfer xfers[2] = { { .tx_buf = sca_data->txbuf, .len = ARRAY_SIZE(sca_data->txbuf), .delay = delay, .cs_change = 1, }, { .rx_buf = sca_data->rxbuf, .len = ARRAY_SIZE(sca_data->rxbuf), .delay = delay, } }; /* inverted crc value as described in device data sheet */ crc = ~crc8(sca3300_crc_table, &sca_data->txbuf[0], 3, CRC8_INIT_VALUE); sca_data->txbuf[3] = crc; ret = spi_sync_transfer(sca_data->spi, xfers, ARRAY_SIZE(xfers)); if (ret) { dev_err(&sca_data->spi->dev, "transfer error, error: %d\n", ret); return -EIO; } crc = ~crc8(sca3300_crc_table, &sca_data->rxbuf[0], 3, CRC8_INIT_VALUE); if (sca_data->rxbuf[3] != crc) { dev_err(&sca_data->spi->dev, "CRC checksum mismatch"); return -EIO; } /* get return status */ rs = sca_data->rxbuf[0] & SCA3300_MASK_RS_STATUS; if (rs == SCA3300_VALUE_RS_ERROR) ret = -EINVAL; *val = sign_extend32(get_unaligned_be16(&sca_data->rxbuf[1]), 15); return ret; } static int sca3300_error_handler(struct sca3300_data *sca_data) { int ret; int val; mutex_lock(&sca_data->lock); sca_data->txbuf[0] = SCA3300_REG_STATUS << 2; ret = sca3300_transfer(sca_data, &val); mutex_unlock(&sca_data->lock); /* * Return status error is cleared after reading status register once, * expect EINVAL here. */ if (ret != -EINVAL) { dev_err(&sca_data->spi->dev, "error reading device status: %d\n", ret); return ret; } dev_err(&sca_data->spi->dev, "device status: 0x%lx\n", val & SCA3300_STATUS_MASK); return 0; } static int sca3300_read_reg(struct sca3300_data *sca_data, u8 reg, int *val) { int ret; mutex_lock(&sca_data->lock); sca_data->txbuf[0] = reg << 2; ret = sca3300_transfer(sca_data, val); mutex_unlock(&sca_data->lock); if (ret != -EINVAL) return ret; return sca3300_error_handler(sca_data); } static int sca3300_write_reg(struct sca3300_data *sca_data, u8 reg, int val) { int reg_val = 0; int ret; mutex_lock(&sca_data->lock); /* BIT(7) for write operation */ sca_data->txbuf[0] = BIT(7) | (reg << 2); put_unaligned_be16(val, &sca_data->txbuf[1]); ret = sca3300_transfer(sca_data, ®_val); mutex_unlock(&sca_data->lock); if (ret != -EINVAL) return ret; return sca3300_error_handler(sca_data); } static int sca3300_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { struct sca3300_data *data = iio_priv(indio_dev); int reg_val; int ret; int i; switch (mask) { case IIO_CHAN_INFO_SCALE: if (val) return -EINVAL; for (i = 0; i < ARRAY_SIZE(sca3300_accel_scale); i++) { if (val2 == sca3300_accel_scale[i][1]) return sca3300_write_reg(data, SCA3300_REG_MODE, i); } return -EINVAL; case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: ret = sca3300_read_reg(data, SCA3300_REG_MODE, ®_val); if (ret) return ret; /* freq. change is possible only for mode 3 and 4 */ if (reg_val == 2 && val == sca3300_lp_freq[3]) return sca3300_write_reg(data, SCA3300_REG_MODE, 3); if (reg_val == 3 && val == sca3300_lp_freq[2]) return sca3300_write_reg(data, SCA3300_REG_MODE, 2); return -EINVAL; default: return -EINVAL; } } static int sca3300_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct sca3300_data *data = iio_priv(indio_dev); int ret; int reg_val; switch (mask) { case IIO_CHAN_INFO_RAW: ret = sca3300_read_reg(data, chan->address, val); if (ret) return ret; return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: ret = sca3300_read_reg(data, SCA3300_REG_MODE, ®_val); if (ret) return ret; *val = 0; *val2 = sca3300_accel_scale[reg_val][1]; return IIO_VAL_INT_PLUS_MICRO; case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: ret = sca3300_read_reg(data, SCA3300_REG_MODE, ®_val); if (ret) return ret; *val = sca3300_lp_freq[reg_val]; return IIO_VAL_INT; default: return -EINVAL; } } static irqreturn_t sca3300_trigger_handler(int irq, void *p) { struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct sca3300_data *data = iio_priv(indio_dev); int bit, ret, val, i = 0; for_each_set_bit(bit, indio_dev->active_scan_mask, indio_dev->masklength) { ret = sca3300_read_reg(data, sca3300_channels[bit].address, &val); if (ret) { dev_err_ratelimited(&data->spi->dev, "failed to read register, error: %d\n", ret); /* handled, but bailing out due to errors */ goto out; } data->scan.channels[i++] = val; } iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, iio_get_time_ns(indio_dev)); out: iio_trigger_notify_done(indio_dev->trig); return IRQ_HANDLED; } /* * sca3300_init - Device init sequence. See datasheet rev 2 section * 4.2 Start-Up Sequence for details. */ static int sca3300_init(struct sca3300_data *sca_data, struct iio_dev *indio_dev) { int value = 0; int ret; ret = sca3300_write_reg(sca_data, SCA3300_REG_MODE, SCA3300_MODE_SW_RESET); if (ret) return ret; /* * Wait 1ms after SW-reset command. * Wait 15ms for settling of signal paths. */ usleep_range(16e3, 50e3); ret = sca3300_read_reg(sca_data, SCA3300_REG_WHOAMI, &value); if (ret) return ret; if (value != SCA3300_WHOAMI_ID) { dev_err(&sca_data->spi->dev, "device id not expected value, %d != %u\n", value, SCA3300_WHOAMI_ID); return -ENODEV; } return 0; } static int sca3300_debugfs_reg_access(struct iio_dev *indio_dev, unsigned int reg, unsigned int writeval, unsigned int *readval) { struct sca3300_data *data = iio_priv(indio_dev); int value; int ret; if (reg > SCA3300_REG_SELBANK) return -EINVAL; if (!readval) return sca3300_write_reg(data, reg, writeval); ret = sca3300_read_reg(data, reg, &value); if (ret) return ret; *readval = value; return 0; } static int sca3300_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, const int **vals, int *type, int *length, long mask) { switch (mask) { case IIO_CHAN_INFO_SCALE: *vals = (const int *)sca3300_accel_scale; *length = ARRAY_SIZE(sca3300_accel_scale) * 2 - 2; *type = IIO_VAL_INT_PLUS_MICRO; return IIO_AVAIL_LIST; case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: *vals = &sca3300_lp_freq[2]; *length = 2; *type = IIO_VAL_INT; return IIO_AVAIL_LIST; default: return -EINVAL; } } static const struct iio_info sca3300_info = { .read_raw = sca3300_read_raw, .write_raw = sca3300_write_raw, .debugfs_reg_access = &sca3300_debugfs_reg_access, .read_avail = sca3300_read_avail, }; static int sca3300_probe(struct spi_device *spi) { struct sca3300_data *sca_data; struct iio_dev *indio_dev; int ret; indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*sca_data)); if (!indio_dev) return -ENOMEM; sca_data = iio_priv(indio_dev); mutex_init(&sca_data->lock); sca_data->spi = spi; crc8_populate_msb(sca3300_crc_table, SCA3300_CRC8_POLYNOMIAL); indio_dev->info = &sca3300_info; indio_dev->name = SCA3300_ALIAS; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = sca3300_channels; indio_dev->num_channels = ARRAY_SIZE(sca3300_channels); indio_dev->available_scan_masks = sca3300_scan_masks; ret = sca3300_init(sca_data, indio_dev); if (ret) { dev_err(&spi->dev, "failed to init device, error: %d\n", ret); return ret; } ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, iio_pollfunc_store_time, sca3300_trigger_handler, NULL); if (ret) { dev_err(&spi->dev, "iio triggered buffer setup failed, error: %d\n", ret); return ret; } ret = devm_iio_device_register(&spi->dev, indio_dev); if (ret) { dev_err(&spi->dev, "iio device register failed, error: %d\n", ret); } return ret; } static const struct of_device_id sca3300_dt_ids[] = { { .compatible = "murata,sca3300"}, {} }; MODULE_DEVICE_TABLE(of, sca3300_dt_ids); static struct spi_driver sca3300_driver = { .driver = { .name = SCA3300_ALIAS, .of_match_table = sca3300_dt_ids, }, .probe = sca3300_probe, }; module_spi_driver(sca3300_driver); MODULE_AUTHOR("Tomas Melin "); MODULE_DESCRIPTION("Murata SCA3300 SPI Accelerometer"); MODULE_LICENSE("GPL v2");