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