Re: [PATCH 2/2] iio: accel: Add driver for Murata SCA3300 accelerometer

Tomas Melin
2021-04-15T08:42:38Z

On 4/12/21 2:08 PM, Jonathan Cameron wrote:

> On Mon, 12 Apr 2021 10:50:56 +0300
> Tomas Melin <tomas.melin@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://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.murata.com%2Fen-global%2Fproducts%2Fsensor%2Faccel%2Fsca3300&amp;data=04%7C01%7Ctomas.melin%40vaisala.com%7Ca66811c95e6c404aa5a208d8fda3743c%7C6d7393e041f54c2e9b124c2be5da5c57%7C0%7C0%7C637538225758011604%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=7bvCd52SFuYdFVlhYrknp0769%2B6hBpxdP6ln0OgKTrE%3D&amp;reserved=0
>>
>> Signed-off-by: Tomas Melin <tomas.melin@vaisala.com>
> Hi Tomas,
>
> Comments below.
>
> Thanks,
>
> Jonathan

Hi Jonathan,

Thanks for your comments! I'll get back with a v2.

While working on updates I did notice something new which I cannot

reproduce on older (5.10.17 kernel) version. If compiling this as a
module, getting error while

unloading module:

[   40.200084] Unable to handle kernel NULL pointer dereference at
virtual address 00000104
...

[   40.510054] Backtrace:
[   40.512502] [<c06c5e0c>] (iio_device_ioctl_handler_unregister) from
[<c06ca8c4>] (iio_buffers_free_sysfs_and_mask+0x2c/0x6c)
[   40.523735] [<c06ca898>] (iio_buffers_free_sysfs_and_mask) from
[<c06c4a18>] (iio_device_unregister+0xa8/0xac)
[   40.533746]  r5:c1811228 r4:c1811000
[   40.537318] [<c06c4970>] (iio_device_unregister) from [<c06c4a38>]
(devm_iio_device_unreg+0x1c/0x20)
[   40.546461]  r5:c2415000 r4:c25bab80
[   40.550025] [<c06c4a1c>] (devm_iio_device_unreg) from [<c0556820>]
(release_nodes+0x1c0/0x1f0)
[   40.558654] [<c0556660>] (release_nodes) from [<c0556bb0>]
(devres_release_all+0x40/0x60)
[   40.566847]  r10:00000081 r9:c2350000 r8:c0100264 r7:00000081
r6:bf00c010 r5:c19be000
[   40.574669]  r4:c1a91c00
[   40.577194] [<c0556b70>] (devres_release_all) from [<c055216c>]
(device_release_driver_internal+0x120/0x1cc)
[   40.587031]  r5:c19be000 r4:c1a91c00
[   40.590596] [<c055204c>] (device_release_driver_internal) from
[<c05522b4>] (driver_detach+0x54/0x90)
[   40.599828]  r7:00000081 r6:00000000 r5:bf00c010 r4:c1a91c00
[   40.605482] [<c0552260>] (driver_detach) from [<c0550ba4>]
(bus_remove_driver+0x5c/0xb0)
[   40.613583]  r5:00000800 r4:bf00c010
[   40.617148] [<c0550b48>] (bus_remove_driver) from [<c0552c38>]
(driver_unregister+0x38/0x5c)
[   40.625596]  r5:00000800 r4:bf00c010
[   40.629161] [<c0552c00>] (driver_unregister) from [<bf00a760>]
(sca3300_driver_exit+0x14/0x8b4 [sca3300])
[   40.638747]  r5:00000800 r4:bf00c080
[   40.642311] [<bf00a74c>] (sca3300_driver_exit [sca3300]) from
[<c01c06f0>] (sys_delete_module+0x16c/0x238)
[   40.651990] [<c01c0584>] (sys_delete_module) from [<c0100244>]
(__sys_trace_return+0x0/0x1c)
[   40.660435] Exception stack(0xc2351fa8 to 0xc2351ff0)
[   40.665484] 1fa0:                   0050e5a8 00000000 0050e5e4
00000800 081d4b00 bec18af4
[   40.673661] 1fc0: 0050e5a8 00000000 bec18b50 00000081 bec18e51
0050e190 00000001 bec18d3c
[   40.681834] 1fe0: 0050cf70 bec18afc 004f1ec8 b6ecb27c
[   40.686887]  r6:bec18b50 r5:00000000 r4:0050e5a8
[   40.691507] Code: e8bd4000 e1c020d0 e3a0cc01 e3001122 (e5823004)
[   40.707675] ---[ end trace 189882b050077333 ]---

This happens when building against linux-next 5.12.0-rc6-next-20210409.
I'm failing to see what is wrong. Any ideas?

Thanks,

Tomas

>
>> ---
>> drivers/iio/accel/Kconfig | 13 ++
>> drivers/iio/accel/Makefile | 1 +
>> drivers/iio/accel/sca3300.c | 434 ++++++++++++++++++++++++++++++++++++
>> 3 files changed, 448 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..112fb88ecd3a
>> --- /dev/null
>> +++ b/drivers/iio/accel/sca3300.c
>> @@ -0,0 +1,434 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +/*
>> + * Copyright (c) Vaisala Oyj. All rights reserved.
> Give a year for the copyright notice if you can.
>
>> + */
>> +#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_X_READ 0
> I wouldn't bother defining this.
>
>> +#define SCA3300_X_WRITE BIT(7)
> Even this one is something I'd just put inline with a comment.
>
>> +#define SCA3300_DEVICE_ID 0x51
>> +#define SCA3300_RS_ERROR 0x3
>> +
>> +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) | \
>> + BIT(IIO_CHAN_INFO_PROCESSED), \
> As mentioned below, don't provide PROCESSED. Userspace is better at handling the
> conversion so leave it to them.
>
>> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
>> + .scan_index = index, \
>> + .scan_type = { \
>> + .sign = 's', \
>> + .realbits = 16, \
>> + .storagebits = 16, \
>> + .shift = 0, \
>> + .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,
>> + .shift = 0,
>> + .endianness = IIO_CPU,
>> + },
>> + },
>> + IIO_CHAN_SOFT_TIMESTAMP(4),
>> +};
>> +
>> +static const int sca3300_accel_scale[] = {2700, 1350, 5400, 5400};
>> +
>> +static const unsigned long sca3300_scan_masks[] = {
>> + BIT(SCA3300_ACC_X) | BIT(SCA3300_ACC_Y) | BIT(SCA3300_ACC_Z) |
>> + BIT(SCA3300_TEMP),
>> + 0};
>> +
>> +/**
>> + * SCA3300 device data
> run scripts/kernel-doc over the file and fix the warnings + errors.
>
>> + *
>> + * @spi SPI device structure
>> + * @opmode Device operation mode
>> + * @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;
>> + u32 opmode;
>> + 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,
>> + .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, 2);
> Use ARRAY_SIZE(xfers) instead of 2.
>
>> + 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)
>> + return rs;
>> +
>> + *val = (s16)(sca_data->rxbuf[2] | (sca_data->rxbuf[1] << 8));
> Preference for an unaligned endian conversion here and explicit sign extend e.g
> something like
>
> sign_extend32(get_unaligned_le16(&sca_data->rxbuf[1]), 15)
>
>> +
>> + 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] = SCA3300_X_READ | (reg << 2);
>> + ret = sca3300_transfer(sca_data, val);
>> + if (ret > 0) {
>> + sca_data->txbuf[0] = SCA3300_X_READ | (SCA3300_REG_STATUS << 2);
>> + ret = sca3300_transfer(sca_data, val);
>> + /* status 0 = startup, 0x2 = mode change */
>> + if (ret > 0 && *val != 0 && *val != 0x2) {
>> + dev_err_ratelimited(&sca_data->spi->dev,
>> + "device status: %x\n",
>> + (u16)*val);
>> + mutex_unlock(&sca_data->lock);
>> + return -EIO;
>> + }
>> + if (ret > 0)
>> + ret = 0;
>> + }
>> + mutex_unlock(&sca_data->lock);
>> +
>> + 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] = SCA3300_X_WRITE | (reg << 2);
>> + sca_data->txbuf[1] = val >> 8;
>> + sca_data->txbuf[2] = val & 0xFF;
> Prefer (Slightly) an unaligned put.
>
>> + ret = sca3300_transfer(sca_data, &reg_val);
>> + if (ret > 0) {
> Factor this error handling out to another function, plus trigger it from an
> appropriate standard error code rather than a positive return value.
>
>> + sca_data->txbuf[0] = SCA3300_X_READ | (SCA3300_REG_STATUS << 2);
>> + ret = sca3300_transfer(sca_data, &reg_val);
>> + /* status 0 = startup, 0x2 = mode change */
>> + if (ret > 0 && reg_val != 0 && reg_val != 0x2) {
>> + dev_err_ratelimited(&sca_data->spi->dev,
>> + "device status: %x\n",
>> + (u16)reg_val);
>> + mutex_unlock(&sca_data->lock);
>> + return -EIO;
>> + }
>> + if (ret > 0)
>> + ret = 0;
> Whenever you get this sort of juggling it rather implies your design is
> less than ideal.
>
>> + }
>> + mutex_unlock(&sca_data->lock);
>> +
>> + 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);
>> +
>> + switch (mask) {
>> + case IIO_CHAN_INFO_SCALE:
>> + if (val < 0 || val > 3)
>> + return -EINVAL;
> No. Scale values need to be the value of 1LSB not a random integer
> that requires you to look up the datasheet.
>
>> + return sca3300_write_reg(data, SCA3300_REG_MODE, val);
>> + 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, &reg_val);
>> + if (ret < 0)
>> + return ret;
>> + *val = sca3300_accel_scale[reg_val];
> Scale is very very rarely an integer value which makes me wonder what
> you are returning here... It should be the multiplier needed to
> take the raw value to a reading in m/sec^2 Given you use it as fractional
> below, I'm guessing this is 1/scale_value?
>
>> + return IIO_VAL_INT;
>> + case IIO_CHAN_INFO_PROCESSED:
> Don't provide processed here. Userspace needs to do the conversion itself
> (and given it has floating point easily available will probably do a better
> job than we can). I'm assuming the mode can't autonomously change?
>
>> + ret = sca3300_read_reg(data, SCA3300_REG_MODE, &reg_val);
>> + if (ret < 0)
>> + return ret;
>> + *val2 = sca3300_accel_scale[reg_val];
>> + ret = sca3300_read_reg(data, chan->address, val);
>> + if (ret < 0)
>> + return ret;
>> + return IIO_VAL_FRACTIONAL;
>> + 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);
>> + s64 time_ns = iio_get_time_ns(indio_dev);
> Is the timestamp at the start more accurate that that at the end
> of reading the channels? If not, just put this inline in the
> iio_push_to_buffers_with_timestamp() call.
>
>> + 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)
> Given we can't return an error code from interrupt handlers, it is usually
> a good idea to print something to the log. Otherwise we get missing data
> with no idea of why..
>
>> + goto out;
>> + if (ARRAY_SIZE(data->scan.channels) > i)
> How could this not be true? If it's always true, don't bother
> checking i.
>
>> + ((s16 *)data->scan.channels)[i++] = val;
>> + }
>> +
>> + iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, time_ns);
>> +out:
>> + iio_trigger_notify_done(indio_dev->trig);
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static int sca3300_init(struct sca3300_data *sca_data,
>> + struct iio_dev *indio_dev)
>> +{
>> + int ret;
>> + int value = 0;
>> +
>> + if (sca_data->opmode < 1 || sca_data->opmode > 4)
>> + return -EINVAL;
> Whilst this is going anyway, better to check that next to where
> it is read so we drop out immediately rather than buried in this
> function.
>
>> +
>> + ret = sca3300_write_reg(sca_data, SCA3300_REG_MODE,
>> + SCA3300_VALUE_SW_RESET);
>> + if (ret != 0)
>> + return ret;
> For sleeps, good to reference which section in data sheet gives the
> timing.
>
>> + usleep_range(2e3, 10e3);
>> +
>> + ret = sca3300_write_reg(sca_data, SCA3300_REG_MODE,
>> + sca_data->opmode - 1);
>> + if (ret != 0)
> if (ret) see below.
>
>> + return ret;
>> + msleep(100);
> Again, document where the time comes from. Saves reviewers time if
> they want to check it. (I'm too lazy :)
>
>> + ret = sca3300_read_reg(sca_data, SCA3300_REG_WHOAMI, &value);
>> + if (ret != 0)
> if (ret) is more idiomatic in kernel code.
>
>> + return ret;
>> +
>> + if (value != SCA3300_DEVICE_ID) {
>> + dev_err(&sca_data->spi->dev, "device id not expected value\n");
> Perhaps useful to print what was expected and what was seen. Maybe it's
> a new variant and this might help the user to identify that and add it to the
> driver.
>
>> + return -EIO;
> -EINVAL probably more appropriate return.
>
>> + }
>> + 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 > 0x1f)
> Use a define that names that register.
>
>> + 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 const struct iio_info sca3300_info = {
>> + .read_raw = sca3300_read_raw,
>> + .write_raw = sca3300_write_raw,
>> + .debugfs_reg_access = &sca3300_debugfs_reg_access,
>> +};
>> +
>> +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;
>> + spi_set_drvdata(spi, indio_dev);
> Won't be used once using devm as below and remove() is dropped, so drop this.
>
>> +
>> + crc8_populate_msb(sca3300_crc_table, SCA3300_CRC8_POLYNOMIAL);
>> +
>> + indio_dev->dev.parent = &spi->dev;
>> + indio_dev->info = &sca3300_info;
>> + indio_dev->name = SCA3300_ALIAS;
>> + indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_TRIGGERED;
> BUFFER_TRIGGERED bit now set by iio_triggered_buffer_setup() so shouldn't
> be ehre as well.
>
>> + indio_dev->channels = sca3300_channels;
>> + indio_dev->num_channels = ARRAY_SIZE(sca3300_channels);
>> + indio_dev->available_scan_masks = sca3300_scan_masks;
>> +
>> + if (spi->dev.of_node) {
>> + ret = of_property_read_u32(spi->dev.of_node, "murata,opmode",
> Please use generic firmware access calls rather than the of specific ones.
> That lets us get ACPI support for free :)
>
> As per the binding review however, this one needs to go in favour of userspace
> control of scale + filter frequencies / sampling freq.
>
>> + &sca_data->opmode);
>> + if (ret < 0)
>> + return ret;
>> + }
>> +
>> + 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 = iio_triggered_buffer_setup(indio_dev, iio_pollfunc_store_time,
>> + sca3300_trigger_handler, NULL);
> devm_iio_triggered_buffer_setup() and you can drop the manual cleanup in remove()
> and hence drop remove() entirely as nothing else left.
>
>> + 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);
>> + iio_triggered_buffer_cleanup(indio_dev);
> With devm above, no need to manually clean this up.
>
>> + return ret;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int sca3300_remove(struct spi_device *spi)
>> +{
>> + struct iio_dev *indio_dev = spi_get_drvdata(spi);
>> +
>> + iio_triggered_buffer_cleanup(indio_dev);
>> + 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,
>> + .remove = sca3300_remove,
>> +};
>> +
>> +module_spi_driver(sca3300_driver);
>> +
>> +MODULE_AUTHOR("Tomas Melin <tomas.melin@vaisala.com>");
>> +MODULE_DESCRIPTION("Murata SCA3300 SPI Accelerometer");
>> +MODULE_LICENSE("GPL v2");