Re: [PATCH 2/2] drivers: iio: accel adxl312 and adxl314 support
From: Jonathan Cameron
Date: Tue Aug 16 2022 - 10:10:18 EST
On Tue, 16 Aug 2022 13:28:28 +0300
George Mois <george.mois@xxxxxxxxxx> wrote:
> ADXL312 and ADXL314 are small, thin, low power, 3-axis accelerometers
> with high resolution (13-bit) measurement up to +/-12 g and +/- 200 g
> respectively.
>
> Implement support for ADXL312 and ADXL314 by extending the ADXL313
> driver.
>
> Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ADXL312.pdf
> Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ADXL314.pdf
>
> Signed-off-by: George Mois <george.mois@xxxxxxxxxx>
Hi George,
Various comments inline.
Thanks,
Jonathan
> ---
> drivers/iio/accel/adxl313.h | 15 ++-
> drivers/iio/accel/adxl313_core.c | 164 +++++++++++++++++++++++--------
> drivers/iio/accel/adxl313_spi.c | 40 +++++++-
> 3 files changed, 173 insertions(+), 46 deletions(-)
>
> diff --git a/drivers/iio/accel/adxl313.h b/drivers/iio/accel/adxl313.h
> index 4415f2fc07e1..7428b1f7768f 100644
> --- a/drivers/iio/accel/adxl313.h
> +++ b/drivers/iio/accel/adxl313.h
> @@ -26,6 +26,7 @@
> #define ADXL313_REG_FIFO_STATUS 0x39
>
> #define ADXL313_DEVID0 0xAD
> +#define ADXL313_DEVID0_ADXL312_314 0xE5
> #define ADXL313_DEVID1 0x1D
> #define ADXL313_PARTID 0xCB
> #define ADXL313_SOFT_RESET 0x52
> @@ -37,18 +38,28 @@
> #define ADXL313_MEASUREMENT_MODE BIT(3)
>
> #define ADXL313_RANGE_MSK GENMASK(1, 0)
> -#define ADXL313_RANGE_4G 3
> +#define ADXL313_RANGE_MAX 3
>
> #define ADXL313_FULL_RES BIT(3)
> #define ADXL313_SPI_3WIRE BIT(6)
> #define ADXL313_I2C_DISABLE BIT(6)
>
> +extern const struct regmap_access_table adxl312_readable_regs_table;
> extern const struct regmap_access_table adxl313_readable_regs_table;
> +extern const struct regmap_access_table adxl314_readable_regs_table;
>
> +extern const struct regmap_access_table adxl312_writable_regs_table;
> extern const struct regmap_access_table adxl313_writable_regs_table;
> +extern const struct regmap_access_table adxl314_writable_regs_table;
> +
> +enum adxl313_device_type {
> + ADXL312,
> + ADXL313,
> + ADXL314,
> +};
>
> int adxl313_core_probe(struct device *dev,
> struct regmap *regmap,
> - const char *name,
> + const struct spi_device_id *id,
> int (*setup)(struct device *, struct regmap *));
> #endif /* _ADXL313_H_ */
> diff --git a/drivers/iio/accel/adxl313_core.c b/drivers/iio/accel/adxl313_core.c
> index afeef779e1d0..eea7d235950e 100644
> --- a/drivers/iio/accel/adxl313_core.c
> +++ b/drivers/iio/accel/adxl313_core.c
> @@ -11,9 +11,17 @@
> #include <linux/iio/iio.h>
> #include <linux/module.h>
> #include <linux/regmap.h>
> +#include <linux/spi/spi.h>
Not in the core driver. This needs to be kept unware of the
buses that migh be used.
>
> #include "adxl313.h"
>
> +static const struct regmap_range adxl312_readable_reg_range[] = {
> + regmap_reg_range(ADXL313_REG_DEVID0, ADXL313_REG_DEVID0),
> + regmap_reg_range(ADXL313_REG_OFS_AXIS(0), ADXL313_REG_OFS_AXIS(2)),
> + regmap_reg_range(ADXL313_REG_THRESH_ACT, ADXL313_REG_ACT_INACT_CTL),
> + regmap_reg_range(ADXL313_REG_BW_RATE, ADXL313_REG_FIFO_STATUS),
> +};
> +
> static const struct regmap_range adxl313_readable_reg_range[] = {
> regmap_reg_range(ADXL313_REG_DEVID0, ADXL313_REG_XID),
> regmap_reg_range(ADXL313_REG_SOFT_RESET, ADXL313_REG_SOFT_RESET),
> @@ -22,12 +30,32 @@ static const struct regmap_range adxl313_readable_reg_range[] = {
> regmap_reg_range(ADXL313_REG_BW_RATE, ADXL313_REG_FIFO_STATUS),
> };
>
> +const struct regmap_access_table adxl312_readable_regs_table = {
> + .yes_ranges = adxl312_readable_reg_range,
> + .n_yes_ranges = ARRAY_SIZE(adxl312_readable_reg_range),
> +};
> +EXPORT_SYMBOL_NS_GPL(adxl312_readable_regs_table, IIO_ADXL312);
> +
> const struct regmap_access_table adxl313_readable_regs_table = {
> .yes_ranges = adxl313_readable_reg_range,
> .n_yes_ranges = ARRAY_SIZE(adxl313_readable_reg_range),
> };
> EXPORT_SYMBOL_NS_GPL(adxl313_readable_regs_table, IIO_ADXL313);
>
> +const struct regmap_access_table adxl314_readable_regs_table = {
> + .yes_ranges = adxl312_readable_reg_range,
> + .n_yes_ranges = ARRAY_SIZE(adxl312_readable_reg_range),
> +};
> +EXPORT_SYMBOL_NS_GPL(adxl314_readable_regs_table, IIO_ADXL314);
> +
> +static const struct regmap_range adxl312_writable_reg_range[] = {
> + regmap_reg_range(ADXL313_REG_OFS_AXIS(0), ADXL313_REG_OFS_AXIS(2)),
> + regmap_reg_range(ADXL313_REG_THRESH_ACT, ADXL313_REG_ACT_INACT_CTL),
> + regmap_reg_range(ADXL313_REG_BW_RATE, ADXL313_REG_INT_MAP),
> + regmap_reg_range(ADXL313_REG_DATA_FORMAT, ADXL313_REG_DATA_FORMAT),
> + regmap_reg_range(ADXL313_REG_FIFO_CTL, ADXL313_REG_FIFO_CTL),
> +};
> +
> static const struct regmap_range adxl313_writable_reg_range[] = {
> regmap_reg_range(ADXL313_REG_SOFT_RESET, ADXL313_REG_SOFT_RESET),
> regmap_reg_range(ADXL313_REG_OFS_AXIS(0), ADXL313_REG_OFS_AXIS(2)),
> @@ -37,16 +65,30 @@ static const struct regmap_range adxl313_writable_reg_range[] = {
> regmap_reg_range(ADXL313_REG_FIFO_CTL, ADXL313_REG_FIFO_CTL),
> };
>
> +const struct regmap_access_table adxl312_writable_regs_table = {
> + .yes_ranges = adxl312_writable_reg_range,
> + .n_yes_ranges = ARRAY_SIZE(adxl312_writable_reg_range),
> +};
> +EXPORT_SYMBOL_NS_GPL(adxl312_writable_regs_table, IIO_ADXL312);
> +
> const struct regmap_access_table adxl313_writable_regs_table = {
> .yes_ranges = adxl313_writable_reg_range,
> .n_yes_ranges = ARRAY_SIZE(adxl313_writable_reg_range),
> };
> EXPORT_SYMBOL_NS_GPL(adxl313_writable_regs_table, IIO_ADXL313);
>
> +const struct regmap_access_table adxl314_writable_regs_table = {
> + .yes_ranges = adxl312_writable_reg_range,
> + .n_yes_ranges = ARRAY_SIZE(adxl312_writable_reg_range),
> +};
> +EXPORT_SYMBOL_NS_GPL(adxl314_writable_regs_table, IIO_ADXL314);
> +
> struct adxl313_data {
> struct regmap *regmap;
> + const struct spi_device_id *id;
> + int scale_factor;
> struct mutex lock; /* lock to protect transf_buf */
> - __le16 transf_buf __aligned(IIO_DMA_MINALIGN);
> + __le16 transf_buf ____cacheline_aligned;
Check your patch for accidental reverts of other changes like this...
> };
>
> static const int adxl313_odr_freqs[][2] = {
> @@ -156,12 +198,10 @@ static int adxl313_read_raw(struct iio_dev *indio_dev,
> *val = sign_extend32(ret, chan->scan_type.realbits - 1);
> return IIO_VAL_INT;
> case IIO_CHAN_INFO_SCALE:
> - /*
> - * Scale for any g range is given in datasheet as
> - * 1024 LSB/g = 0.0009765625 * 9.80665 = 0.009576806640625 m/s^2
> - */
> *val = 0;
> - *val2 = 9576806;
> +
> + *val2 = data->scale_factor;
I'd move this into a structure containing all the chip type specific data.
Hence this would be
data->chip.scale_factor.
> +
> return IIO_VAL_INT_PLUS_NANO;
> case IIO_CHAN_INFO_CALIBBIAS:
> ret = regmap_read(data->regmap,
> @@ -170,7 +210,7 @@ static int adxl313_read_raw(struct iio_dev *indio_dev,
> return ret;
>
> /*
> - * 8-bit resolution at +/- 0.5g, that is 4x accel data scale
> + * 8-bit resolution at minimum range, that is 4x accel data scale
> * factor at full resolution
> */
> *val = sign_extend32(regval, 7) * 4;
> @@ -198,7 +238,7 @@ static int adxl313_write_raw(struct iio_dev *indio_dev,
> switch (mask) {
> case IIO_CHAN_INFO_CALIBBIAS:
> /*
> - * 8-bit resolution at +/- 0.5g, that is 4x accel data scale
> + * 8-bit resolution at minimum range, that is 4x accel data scale
> * factor at full resolution
> */
> if (clamp_val(val, -128 * 4, 127 * 4) != val)
> @@ -223,14 +263,17 @@ static const struct iio_info adxl313_info = {
> static int adxl313_setup(struct device *dev, struct adxl313_data *data,
> int (*setup)(struct device *, struct regmap *))
> {
> + enum adxl313_device_type dev_type = data->id->driver_data;
> unsigned int regval;
> int ret;
>
> - /* Ensures the device is in a consistent state after start up */
> - ret = regmap_write(data->regmap, ADXL313_REG_SOFT_RESET,
> - ADXL313_SOFT_RESET);
> - if (ret)
> - return ret;
> + /* If ADXL313, ensures the device is in a consistent state after start up */
> + if (dev_type == ADXL313) {
Add a flag to the chip_info structure suggested below for 'soft_reset' and
base this decision on that. The aim is to encode all the variations in chips
in one place so adding future chips is isolated there.
> + ret = regmap_write(data->regmap, ADXL313_REG_SOFT_RESET,
> + ADXL313_SOFT_RESET);
> + if (ret)
> + return ret;
> + }
>
> if (setup) {
> ret = setup(dev, data->regmap);
> @@ -242,41 +285,54 @@ static int adxl313_setup(struct device *dev, struct adxl313_data *data,
> if (ret)
> return ret;
>
> - if (regval != ADXL313_DEVID0) {
> + if (dev_type == ADXL313 && regval != ADXL313_DEVID0) {
Obviously this predates your changes...
Don't fail in this case. Warn only. We may be dealing with a newer compatible
device that falls back to an the ADXL313 compatible in dt. It's fine to express
we don't know what it is - particularly if ID matches something else, but
not to fail as a result.
> dev_err(dev, "Invalid manufacturer ID: 0x%02x\n", regval);
> return -ENODEV;
> }
>
> - ret = regmap_read(data->regmap, ADXL313_REG_DEVID1, ®val);
> - if (ret)
> - return ret;
> + /* If ADXL313, check DEVID1 and PARTID */
> + if (regval == ADXL313_DEVID0) {
> + ret = regmap_read(data->regmap, ADXL313_REG_DEVID1, ®val);
> + if (ret)
> + return ret;
>
> - if (regval != ADXL313_DEVID1) {
As above, should not fail - but just give a warning message (or dev_info perhaps).
> - dev_err(dev, "Invalid mems ID: 0x%02x\n", regval);
> - return -ENODEV;
> - }
> + if (regval != ADXL313_DEVID1) {
> + dev_err(dev, "Invalid mems ID: 0x%02x\n", regval);
> + return -ENODEV;
> + }
>
> - ret = regmap_read(data->regmap, ADXL313_REG_PARTID, ®val);
> - if (ret)
> - return ret;
> + ret = regmap_read(data->regmap, ADXL313_REG_PARTID, ®val);
> + if (ret)
> + return ret;
>
> - if (regval != ADXL313_PARTID) {
> - dev_err(dev, "Invalid device ID: 0x%02x\n", regval);
> + if (regval != ADXL313_PARTID) {
> + dev_err(dev, "Invalid device ID: 0x%02x\n", regval);
> + return -ENODEV;
> + }
> + }
> +
> + /* If ADXL312 or ADXL314 device, check DEVID0 */
> + if (dev_type != ADXL313 && regval != ADXL313_DEVID0_ADXL312_314) {
> + dev_err(dev, "Invalid manufacturer ID: %#02x\n", regval);
> return -ENODEV;
> }
>
> - /* Sets the range to +/- 4g */
> - ret = regmap_update_bits(data->regmap, ADXL313_REG_DATA_FORMAT,
> - ADXL313_RANGE_MSK,
> - FIELD_PREP(ADXL313_RANGE_MSK, ADXL313_RANGE_4G));
> - if (ret)
> - return ret;
> + dev_info(dev, "%s detected.\n", data->id->name);
Noise in the log. Drop this. It's easy to find out the name from sysfs.
>
> - /* Enables full resolution */
> - ret = regmap_update_bits(data->regmap, ADXL313_REG_DATA_FORMAT,
> - ADXL313_FULL_RES, ADXL313_FULL_RES);
> - if (ret)
> - return ret;
> + /* Sets the range to maximum, full resolution, for ADXL312 and ADXL313 */
> + if (dev_type == ADXL312 || dev_type == ADXL313) {
I'm reading this backwards btw. As below, this sort of thing should depend on
contents of a chip_info structure.
In this case perhaps a flag called 'set max range').
> + ret = regmap_update_bits(data->regmap, ADXL313_REG_DATA_FORMAT,
> + ADXL313_RANGE_MSK,
> + FIELD_PREP(ADXL313_RANGE_MSK, 0x02));
0x02 looks like a magic numbers, you should ideally provide a define.
> + if (ret)
> + return ret;
> +
> + /* Enables full resolution */
> + ret = regmap_update_bits(data->regmap, ADXL313_REG_DATA_FORMAT,
> + ADXL313_FULL_RES, 0);
> + if (ret)
> + return ret;
> + }
>
> /* Enables measurement mode */
> return regmap_update_bits(data->regmap, ADXL313_REG_POWER_CTL,
> @@ -296,7 +352,7 @@ static int adxl313_setup(struct device *dev, struct adxl313_data *data,
> */
> int adxl313_core_probe(struct device *dev,
> struct regmap *regmap,
> - const char *name,
> + const struct spi_device_id *id,
A core probe function shouldn't be taking an SPI specific structure.
Fine to pass the id enum entry. That can then index a chip_info structure
that includes the part name - we don't want to pass that through this interface
as well.
> int (*setup)(struct device *, struct regmap *))
> {
> struct adxl313_data *data;
> @@ -309,9 +365,35 @@ int adxl313_core_probe(struct device *dev,
>
> data = iio_priv(indio_dev);
> data->regmap = regmap;
> + data->id = id;
> +
> + if (id->driver_data == ADXL312)
Whenever you hit a case like this, it almost always means you should be selecting
from an array of chip_info structures. One per type of chip.
If it is possible to convert code to data that is almost always a good idea.
> + /*
> + * ADXL312
> + * Scale for any g range (full range) is given in datasheet as
> + * 345 LSB/g = 0.0028985507 * 9.80665 = 0.028425072222155 m/s^2
> + */
> + data->scale_factor = 28425072;
> +
> + if (id->driver_data == ADXL313)
> + /*
> + * * ADXL313
> + * Scale for any g range is given in datasheet as
> + * 1024 LSB/g = 0.0009765625 * 9.80665 = 0.009576806640625 m/s^2
> + */
> + data->scale_factor = 9576806;
> +
> + if (id->driver_data == ADXL314)
> + /*
> + * ADXL314
> + * At +/-200g with 13-bit resolution, scale factor is given in datasheet as
> + * 48.83 mg/LSB = 0.0488300 * 9.80665 = 0.4788587195 m/s^2.
> + */
> + data->scale_factor = 478858719;
> +
> mutex_init(&data->lock);
>
> - indio_dev->name = name;
> + indio_dev->name = id->name;
> indio_dev->info = &adxl313_info;
> indio_dev->modes = INDIO_DIRECT_MODE;
> indio_dev->channels = adxl313_channels;
> @@ -319,13 +401,13 @@ int adxl313_core_probe(struct device *dev,
>
> ret = adxl313_setup(dev, data, setup);
> if (ret) {
> - dev_err(dev, "ADXL313 setup failed\n");
> + dev_err(dev, "Device %s setup failed\n", id->name);
I doubt we'll ever care which part it was that failed. I'd
just leave that as it waas.
> return ret;
> }
>
> return devm_iio_device_register(dev, indio_dev);
> }
> -EXPORT_SYMBOL_NS_GPL(adxl313_core_probe, IIO_ADXL313);
> +EXPORT_SYMBOL_GPL(adxl313_core_probe);
Please don't remove the namespacing. Add any new exports to the
existing IIO_ADXL313 NS.
>
> MODULE_AUTHOR("Lucas Stankus <lucas.p.stankus@xxxxxxxxx>");
> MODULE_DESCRIPTION("ADXL313 3-Axis Digital Accelerometer core driver");
> diff --git a/drivers/iio/accel/adxl313_spi.c b/drivers/iio/accel/adxl313_spi.c
> index a3c6d553462d..19cd096373b0 100644
> --- a/drivers/iio/accel/adxl313_spi.c
> +++ b/drivers/iio/accel/adxl313_spi.c
> @@ -14,6 +14,16 @@
>
> #include "adxl313.h"
>
> +static const struct regmap_config adxl312_spi_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> + .rd_table = &adxl312_readable_regs_table,
> + .wr_table = &adxl312_writable_regs_table,
> + .max_register = 0x39,
> + /* Setting bits 7 and 6 enables multiple-byte read */
> + .read_flag_mask = BIT(7) | BIT(6),
> +};
> +
> static const struct regmap_config adxl313_spi_regmap_config = {
> .reg_bits = 8,
> .val_bits = 8,
> @@ -24,6 +34,22 @@ static const struct regmap_config adxl313_spi_regmap_config = {
> .read_flag_mask = BIT(7) | BIT(6),
> };
>
> +static const struct regmap_config adxl314_spi_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> + .rd_table = &adxl314_readable_regs_table,
> + .wr_table = &adxl314_writable_regs_table,
> + .max_register = 0x39,
> + /* Setting bits 7 and 6 enables multiple-byte read */
> + .read_flag_mask = BIT(7) | BIT(6),
> +};
> +
> +static const struct regmap_config adxl31x_spi_regmap_config[] = {
> + adxl312_spi_regmap_config,
> + adxl313_spi_regmap_config,
> + adxl314_spi_regmap_config
> +};
> +
> static int adxl313_spi_setup(struct device *dev, struct regmap *regmap)
> {
> struct spi_device *spi = container_of(dev, struct spi_device, dev);
> @@ -51,26 +77,32 @@ static int adxl313_spi_probe(struct spi_device *spi)
> if (ret)
> return ret;
>
> - regmap = devm_regmap_init_spi(spi, &adxl313_spi_regmap_config);
> + regmap = devm_regmap_init_spi(spi,
> + &adxl31x_spi_regmap_config[id->driver_data]);
> +
> if (IS_ERR(regmap)) {
> dev_err(&spi->dev, "Error initializing spi regmap: %ld\n",
> PTR_ERR(regmap));
> return PTR_ERR(regmap);
> }
>
> - return adxl313_core_probe(&spi->dev, regmap, id->name,
> + return adxl313_core_probe(&spi->dev, regmap, id,
> &adxl313_spi_setup);
> }
>
> static const struct spi_device_id adxl313_spi_id[] = {
> - { "adxl313" },
> + { "adxl312", ADXL312 },
> + { "adxl313", ADXL313 },
> + { "adxl314", ADXL314 },
> { }
> };
>
> MODULE_DEVICE_TABLE(spi, adxl313_spi_id);
>
> static const struct of_device_id adxl313_of_match[] = {
> + { .compatible = "adi,adxl312" },
> { .compatible = "adi,adxl313" },
> + { .compatible = "adi,adxl314" },
> { }
As mentioned in other thread, there is a nicer way of handling
the different types of firmware ID.
> };
>
> @@ -90,4 +122,6 @@ module_spi_driver(adxl313_spi_driver);
> MODULE_AUTHOR("Lucas Stankus <lucas.p.stankus@xxxxxxxxx>");
> MODULE_DESCRIPTION("ADXL313 3-Axis Digital Accelerometer SPI driver");
> MODULE_LICENSE("GPL v2");
> +MODULE_IMPORT_NS(IIO_ADXL312);
Take a look at what this is doing. There is only one namespace for the
driver, not one per chip type.
> MODULE_IMPORT_NS(IIO_ADXL313);
> +MODULE_IMPORT_NS(IIO_ADXL314);