On Fri, Apr 16, 2021 at 5:21 PM Tomas Melin <tomas.melin@xxxxxxxxxxx> 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 Can you create a tag out of it, i.e. Datasheet: <URL> ? > Signed-off-by: Tomas Melin <tomas.melin@xxxxxxxxxxx> ... > obj-$(CONFIG_SCA3000) += sca3000.o > +obj-$(CONFIG_SCA3300) += sca3300.o How much difference between them? ... > +/* > + * Copyright (c) 2021 Vaisala Oyj. All rights reserved. > + */ One line > +#include <asm/unaligned.h> Usually asm/* goes after linux/* > +#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> Can you move this below... > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/spi/spi.h> ...here. So, you will have something like this at the end: linux/* asm/* linux/iio* ... > +#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 Is it mask or value or offset? > +#define SCA3300_STATUS_MASK 0x1ff GENMASK() TAB indentation to all? This all like an unordered pile of something. I can't guess the value for which register and so on. Can you put an order here? ... > +#define SCA3300_ACCEL_CHANNEL(index, reg, axis) { \ > + } Something wrong with indentation here. ... > +static const int sca3300_accel_scale[][2] = {{0, 370}, {0, 741}, {0, 185}, > + {0, 185}}; Put it all on one line. ... > +static const unsigned long sca3300_scan_masks[] = { > + BIT(SCA3300_ACC_X) | BIT(SCA3300_ACC_Y) | BIT(SCA3300_ACC_Z) | > + BIT(SCA3300_TEMP), > + 0}; Something wrong with indentation, i.e. }; should be on the following line. ... > +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, > + .rx_buf = sca_data->rxbuf, > + .len = ARRAY_SIZE(sca_data->rxbuf), > + .delay = delay, > + .cs_change = 0, > + } > + }; > + > + /* 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; Why shadowing error code? > + } > + > + 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; What's 0x3? Shouldn't it be defined with a descriptive name? > + 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) { Why this? Comment above is confusing, see also the comments below. > + 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 casting here?! > + 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); What is the meaning of the 0x0? Comment, please. > + ret = sca3300_transfer(sca_data, val); > + mutex_unlock(&sca_data->lock); > + if (ret == -EINVAL) This needs a good comment. > + ret = sca3300_error_handler(sca_data); > + > + return ret; if (ret != -EINVAL) return ret; return _error_handler(...); > +} > + > +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; > +} As per above. ... > + for (i = 0; i < ARRAY_SIZE(sca3300_accel_scale); i++) { > + if (val2 == sca3300_accel_scale[i][1]) { > + idx = i; Redundant variable. Refactor w/o using it. It's easy. > + break; > + } > + } > + if (idx == -1) > + return -EINVAL; ... > + /* 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; Two times redundant 'else' ... > +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; > + } > + > + 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; > +} > + ... > + ret = sca3300_write_reg(sca_data, SCA3300_REG_MODE, > + SCA3300_VALUE_SW_RESET); > + if (ret != 0) if (ret) Everywhere in the code. > + return ret; + blank line > + /* wait at least 1ms after SW-reset command */ > + usleep_range(1e3, 10e3); This doesn't make any difference. You may simply drop it and unify the comments. > + /* wait 15ms for settling of signal paths */ > + usleep_range(15e3, 50e3); ... > + 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; -ENODEV ? > + } ... > +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; While casting? > + return 0; > +} If you switch to use regmap, the read part will be a bonus automatically. ... > + 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"); Noice. You will get the same from user space. > + return -ENOMEM; > + } ... > + indio_dev->dev.parent = &spi->dev; This is done by IIO core. ... > + 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; return ret; > +} ... > +static const struct of_device_id sca3300_dt_ids[] = { > + { .compatible = "murata,sca3300"}, > + {}, Drop comma. No need for a terminator line. > +}; ... > +static struct spi_driver sca3300_driver = { > + .driver = { > + .name = SCA3300_ALIAS, > + .owner = THIS_MODULE, Redundant. > + .of_match_table = of_match_ptr(sca3300_dt_ids), Drop of_match_ptr(). In 99% its use is wrong. > + }, > + > + .probe = sca3300_probe, > +}; -- With Best Regards, Andy Shevchenko
