On Fri, 16 Apr 2021 16:45:46 +0300 Tomas Melin <tomas.me...@vaisala.com> wrote:
> Add initial support for Murata SCA3300 3-axis industrial > accelerometer with digital SPI interface. This device also > provides a temperature measurement. > > Device product page including datasheet can be found at: > https://www.murata.com/en-global/products/sensor/accel/sca3300 > > Signed-off-by: Tomas Melin <tomas.me...@vaisala.com> A few things inline. Mostly looks pretty good Jonathan > --- > drivers/iio/accel/Kconfig | 13 + > drivers/iio/accel/Makefile | 1 + > drivers/iio/accel/sca3300.c | 468 ++++++++++++++++++++++++++++++++++++ > 3 files changed, 482 insertions(+) > create mode 100644 drivers/iio/accel/sca3300.c > > diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig > index cceda3cecbcf..0dbf7b648e8a 100644 > --- a/drivers/iio/accel/Kconfig > +++ b/drivers/iio/accel/Kconfig > @@ -450,6 +450,19 @@ config SCA3000 > To compile this driver as a module, say M here: the module will be > called sca3000. > > +config SCA3300 > + tristate "Murata SCA3300 3-Axis Accelerometer Driver" > + depends on SPI > + select CRC8 > + select IIO_BUFFER > + select IIO_TRIGGERED_BUFFER > + help > + Say yes here to build support for Murata SCA3300 3-Axis > + accelerometer. > + > + To compile this driver as a module, choose M here: the module will be > + called sca3300. > + > config STK8312 > tristate "Sensortek STK8312 3-Axis Accelerometer Driver" > depends on I2C > diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile > index 32cd1342a31a..4b56527a2b97 100644 > --- a/drivers/iio/accel/Makefile > +++ b/drivers/iio/accel/Makefile > @@ -50,6 +50,7 @@ obj-$(CONFIG_MXC4005) += mxc4005.o > obj-$(CONFIG_MXC6255) += mxc6255.o > > obj-$(CONFIG_SCA3000) += sca3000.o > +obj-$(CONFIG_SCA3300) += sca3300.o > > obj-$(CONFIG_STK8312) += stk8312.o > obj-$(CONFIG_STK8BA50) += stk8ba50.o > diff --git a/drivers/iio/accel/sca3300.c b/drivers/iio/accel/sca3300.c > new file mode 100644 > index 000000000000..79c3c60f9fab > --- /dev/null > +++ b/drivers/iio/accel/sca3300.c > @@ -0,0 +1,468 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright (c) 2021 Vaisala Oyj. All rights reserved. > + */ > +#include <asm/unaligned.h> Slight preference for 'specific' includes such asm after the generic linux ones. > +#include <linux/bitops.h> > +#include <linux/crc8.h> > +#include <linux/delay.h> > +#include <linux/iio/buffer.h> > +#include <linux/iio/iio.h> > +#include <linux/iio/sysfs.h> > +#include <linux/iio/trigger_consumer.h> > +#include <linux/iio/triggered_buffer.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/spi/spi.h> > + > +#define SCA3300_ALIAS "sca3300" > + > +#define SCA3300_REG_STATUS 0x6 > +#define SCA3300_REG_MODE 0xd > +#define SCA3300_REG_WHOAMI 0x10 > +#define SCA3300_VALUE_SW_RESET 0x20 > +#define SCA3300_CRC8_POLYNOMIAL 0x1d > +#define SCA3300_DEVICE_ID 0x51 > +#define SCA3300_RS_ERROR 0x3 > +#define SCA3300_SELBANK 0x1f > +#define SCA3300_STATUS_MASK 0x1ff > + > +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, \ > + .shift = 0, \ > + .endianness = IIO_CPU, \ > + }, \ > + } Alignment done something odd here and above. Editors get confused by macros so you might need to tweak this carefully! > + > +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, > + .shift = 0, Obviously default, so no need to specify a shift of 0. > + .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 > + * @txbuf: Transmit buffer > + * @rxbuf: Receive buffer > + * @scan: Triggered buffer. Four channel 16-bit data + 64-bit timestamp > + */ > +struct sca3300_data { > + struct spi_device *spi; > + struct mutex lock; > + u8 txbuf[4]; > + u8 rxbuf[4]; > + struct { > + s16 channels[4]; > + s64 ts __aligned(sizeof(s64)); > + } scan; > +}; > + > +DECLARE_CRC8_TABLE(sca3300_crc_table); > + > +static int sca3300_transfer(struct sca3300_data *sca_data, int *val) > +{ > + 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, > + .rx_buf = NULL, > + .len = ARRAY_SIZE(sca_data->txbuf), > + .delay = delay, > + .cs_change = 1, > + }, > + { > + .tx_buf = NULL, Obvious default, don't bother specifying these buffers are NULL. > + .rx_buf = sca_data->rxbuf, > + .len = ARRAY_SIZE(sca_data->rxbuf), > + .delay = delay, > + .cs_change = 0, That should be obvious default, so don't bother specifying it. > + } > + }; > + > + /* 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 < 0) { > + 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] & 0x03; > + if (rs == SCA3300_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] = 0x0 | (SCA3300_REG_STATUS << 2); > + ret = sca3300_transfer(sca_data, &val); > + mutex_unlock(&sca_data->lock); > + /* return status is cleared after reading status register */ > + 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%x\n", > + (u16)(val & SCA3300_STATUS_MASK)); Why the cast? Not sure it does anything useful. > + 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] = 0x0 | (reg << 2); > + ret = sca3300_transfer(sca_data, val); > + mutex_unlock(&sca_data->lock); > + if (ret == -EINVAL) > + ret = sca3300_error_handler(sca_data); > + > + return ret; > +} > + > +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); > + 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) > + ret = sca3300_error_handler(sca_data); > + > + return ret; > +} > + > +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; > + int idx = -1; > + > + 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]) { > + idx = i; > + break; > + } > + } > + if (idx == -1) > + return -EINVAL; > + > + return sca3300_write_reg(data, SCA3300_REG_MODE, idx); > + case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: > + ret = sca3300_read_reg(data, SCA3300_REG_MODE, ®_val); > + if (ret < 0) > + 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); > + else if (reg_val == 3 && val == sca3300_lp_freq[2]) > + return sca3300_write_reg(data, SCA3300_REG_MODE, 2); > + else > + 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 < 0) > + return ret; > + return IIO_VAL_INT; > + case IIO_CHAN_INFO_SCALE: > + ret = sca3300_read_reg(data, SCA3300_REG_MODE, ®_val); > + if (ret < 0) > + 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 < 0) > + 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 < 0) { > + dev_err(&data->spi->dev, > + "failed to read register, error: %d\n", ret); > + goto out; > + } > + ((s16 *)data->scan.channels)[i++] = val; Why do you need the cast? > + } > + > + 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 ret; > + int value = 0; > + > + ret = sca3300_write_reg(sca_data, SCA3300_REG_MODE, > + SCA3300_VALUE_SW_RESET); > + if (ret != 0) > + return ret; > + /* wait at least 1ms after SW-reset command */ > + usleep_range(1e3, 10e3); > + > + /* wait 15ms for settling of signal paths */ > + usleep_range(15e3, 50e3); > + ret = sca3300_read_reg(sca_data, SCA3300_REG_WHOAMI, &value); > + if (ret != 0) For error checks we tend to just use if (ret) Same in a few other places. > + return ret; > + > + if (value != SCA3300_DEVICE_ID) { > + dev_err(&sca_data->spi->dev, > + "device id not expected value, %d != %u\n", > + value, SCA3300_DEVICE_ID); > + return -EIO; > + } > + 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_SELBANK) > + return -EINVAL; > + > + if (!readval) > + return sca3300_write_reg(data, reg, writeval); > + > + ret = sca3300_read_reg(data, reg, &value); > + if (ret < 0) > + return ret; > + > + *readval = (unsigned int)value; > + > + return 0; > +} > + > +static int sca3300_read_avail(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + const int **vals, You could wrap this a little less without hurting readability I think. > + 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) { > + dev_err(&spi->dev, > + "failed to allocate memory for iio device\n"); > + 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->dev.parent = &spi->dev; This should now be set by the IIO core IIRC. > + 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 < 0) { > + 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 < 0) { > + 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 < 0) { > + dev_err(&spi->dev, "iio device register failed, error: %d\n", > + ret); > + return ret; > + } > + > + return 0; > +} > + > +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, > + .owner = THIS_MODULE, > + .of_match_table = of_match_ptr(sca3300_dt_ids), > + }, > + > + .probe = sca3300_probe, > +}; > + > +module_spi_driver(sca3300_driver); > + > +MODULE_AUTHOR("Tomas Melin <tomas.me...@vaisala.com>"); > +MODULE_DESCRIPTION("Murata SCA3300 SPI Accelerometer"); > +MODULE_LICENSE("GPL v2");
