Re: Use LIS3MDL with LSM6DSM sensor-hub

[Jimmy Assarsson <jimmyassarsson@gmail.com>]

On 2020-03-19 18:40, Lorenzo Bianconi wrote:
>> On 2020-03-14 13:43, Lorenzo Bianconi wrote:
>>> On Mar 11, Jimmy Assarsson wrote:
>>>> Hi,
>>>>
>>>> We are working on a project where we want to connect LS6DSM (via SPI), and
>>>> connect LIS3MDL via the sensor hub, as I2C slave device.
>>>>
>>>> We would like to add settings/configuration for LIS3MDL, to the shub
>>>> source, since currently only LIS2MDL is supported. We've made an attempt,
>>>> see diff at end of this mail.
>>>>
>>>> 1. LIS2MDL only got a single full scale setting, hence it is not possible
>>>>      to change. While LIS3MDL got four possible settings. Is it enough to add
>>>>      a corresponding function like st_lsm6dsx_shub_set_fs_val() and call it
>>>>      from st_lsm6dsx_shub_write_raw(), when mask == IIO_CHAN_INFO_SCALE?
>>>> 2. LIS3MDL got 8 possible ODR settings, however ST_LSM6DSX_ODR_LIST_SIZE is
>>>>      defined to 6 (st_lsm6dsx.h). Is it fine to increase
>>>>      ST_LSM6DSX_ODR_LIST_SIZE to 8? This will also affect odr_table in
>>>>      struct st_lsm6dsx_settings.
>>>> 3. In the patch, we've tried to copy the correct registers and values from
>>>>      magnetometer/st_magn_core.c, does it look ok?
>>>>
>>>> The IIO subsystem is new to use, we possibly miss fundamental knowledge.
>>>>
>>>> Regards,
>>>> jimmy
>>>
>>> Hi Jimmy,
>>>
>>> in order to set the full scale on LIS3MDL you can try the following patch (just
>>> compiled, not tested)
>>>
>>> Regards,
>>> Lorenzo
>>
>> Hi Lorenzo,
>>
>> Sorry for the late response and thanks for the patch!
> 
> Hi Jimmy,
> 
> ok, I will post the patch, thx for testing.

Great, you can add
Tested-by: Jimmy Assarsson <jimmyassarsson@gmail.com>

>> The patches seems to work.
>> Are there any specific tests that we should carry out?
>> Via the sysfs interface, we've tested reading raw values of each channel and
>> configuring ODR and full scale.
> 
> you can try to enable batching in the hw FIFO doing something like:
> 
> $echo 1 > /sys/bus/iio/devices/<iio-magn>/scan_elements/in_magn_x_en
> $echo 1 > /sys/bus/iio/devices/<iio-magn>/scan_elements/in_magn_y_en
> $echo 1 > /sys/bus/iio/devices/<iio-magn>/scan_elements/in_magn_z_en
> $echo 1 > /sys/bus/iio/devices/<iio-magn>/scan_elements/in_timestamp_en
> 
> $watermark=64
> $echo $((2*watermark)) > /sys/bus/iio/devices/<iio-magn>/buffer/length
> $echo $watermark > /sys/bus/iio/devices/<iio-magn>/buffer/watermark
> 
> $generic_buffer -gn lsm6dsm_magn -c <# of samples>

Ok. I don't got any scan_elements nor buffer directory, for any of the devices.
I guess it is not possible to use the FIFO without configuring any interrupt?
We got the following dts:
&spi1 {
	#address-cells = <1>;
	#size-cells = <0>;
	lsm6dsm@0 {
		compatible = "st,lsm6dsm";
		reg = <0x0>;

		spi-max-frequency = <500000>;
		st,pullups = "true";
	};
};

I'll look into this tomorrow or in the beginning of next week, thanks for the help.

Regards,
jimmy

> 
> Regards,
> Lorenzo
> 
>>
>> Regards,
>> jimmy
>>
>>> diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_shub.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_shub.c
>>> index 64ef07a30726..fec1dbd5f00d 100644
>>> --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_shub.c
>>> +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_shub.c
>>> @@ -518,6 +518,36 @@ st_lsm6dsx_shub_read_raw(struct iio_dev *iio_dev,
>>>    	return ret;
>>>    }
>>> +static int
>>> +st_lsm6dsx_shub_set_full_scale(struct st_lsm6dsx_sensor *sensor,
>>> +			       u32 gain)
>>> +{
>>> +	const struct st_lsm6dsx_fs_table_entry *fs_table;
>>> +	int i, err;
>>> +
>>> +	fs_table = &sensor->ext_info.settings->fs_table;
>>> +	if (!fs_table->reg.addr)
>>> +		return -ENOTSUPP;
>>> +
>>> +	for (i = 0; i < fs_table->fs_len; i++) {
>>> +		if (fs_table->fs_avl[i].gain == gain)
>>> +			break;
>>> +	}
>>> +
>>> +	if (i == fs_table->fs_len)
>>> +		return -EINVAL;
>>> +
>>> +	err = st_lsm6dsx_shub_write_with_mask(sensor, fs_table->reg.addr,
>>> +					      fs_table->reg.mask,
>>> +					      fs_table->fs_avl[i].val);
>>> +	if (err < 0)
>>> +		return err;
>>> +
>>> +	sensor->gain = gain;
>>> +
>>> +	return 0;
>>> +}
>>> +
>>>    static int
>>>    st_lsm6dsx_shub_write_raw(struct iio_dev *iio_dev,
>>>    			  struct iio_chan_spec const *chan,
>>> @@ -552,6 +582,9 @@ st_lsm6dsx_shub_write_raw(struct iio_dev *iio_dev,
>>>    		}
>>>    		break;
>>>    	}
>>> +	case IIO_CHAN_INFO_SCALE:
>>> +		err = st_lsm6dsx_shub_set_full_scale(sensor, val2);
>>> +		break;
>>>    	default:
>>>    		err = -EINVAL;
>>>    		break;
>>>
>>>>
>>>> ---
>>>> diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_shub.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_shub.c
>>>> index eea5556..8621dba 100644
>>>> --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_shub.c
>>>> +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_shub.c
>>>> @@ -88,6 +88,69 @@ static const struct st_lsm6dsx_ext_dev_settings st_lsm6dsx_ext_dev_table[] = {
>>>>    			.len = 6,
>>>>    		},
>>>>    	},
>>>> +	/* LIS3MDL */
>>>> +	{
>>>> +		.i2c_addr = { 0x1e },
>>>> +		.wai = {
>>>> +			.addr = 0x0f,
>>>> +			.val = 0x3d,
>>>> +		},
>>>> +		.id = ST_LSM6DSX_ID_MAGN,
>>>> +		.odr_table = {
>>>> +			.reg = {
>>>> +				.addr = 0x20,
>>>> +				.mask = GENMASK(4, 2),
>>>> +			},
>>>> +			.odr_avl[0] = {  1000, 0x0 },
>>>> +			.odr_avl[1] = {  2000, 0x1 },
>>>> +			.odr_avl[2] = {  3000, 0x2 },
>>>> +			.odr_avl[3] = {  5000, 0x3 },
>>>> +			.odr_avl[4] = { 10000, 0x4 },
>>>> +			.odr_avl[5] = { 20000, 0x5 },
>>>> +			.odr_avl[6] = { 40000, 0x6 },
>>>> +			.odr_avl[7] = { 80000, 0x7 },
>>>> +			.odr_len = 8,
>>>> +		},
>>>> +		.fs_table = {
>>>> +			.reg = {
>>>> +				.addr = 0x21,
>>>> +				.mask = GENMASK(6, 5),
>>>> +			},
>>>> +			.fs_avl[0] = {
>>>> +				.gain = 146,
>>>> +				.val = 0x00,
>>>> +			}, /* 4000 uG/LSB */
>>>> +			.fs_avl[1] = {
>>>> +				.gain = 292,
>>>> +				.val = 0x01,
>>>> +			}, /* 8000 uG/LSB */
>>>> +			.fs_avl[2] = {
>>>> +				.gain = 438,
>>>> +				.val = 0x02,
>>>> +			}, /* 12000 uG/LSB */
>>>> +			.fs_avl[3] = {
>>>> +				.gain = 584,
>>>> +				.val = 0x03,
>>>> +			}, /* 16000 uG/LSB */
>>>> +			.fs_len = 4,
>>>> +		},
>>>> +		.pwr_table = {
>>>> +			.reg = {
>>>> +				.addr = 0x22,
>>>> +				.mask = GENMASK(1, 0),
>>>> +			},
>>>> +			.off_val = 0x2,
>>>> +			.on_val = 0x0,
>>>> +		},
>>>> +		.bdu = {
>>>> +			.addr = 0x24,
>>>> +			.mask = BIT(6),
>>>> +		},
>>>> +		.out = {
>>>> +			.addr = 0x28,
>>>> +			.len = 6,
>>>> +		},
>>>> +	},
>>>>    };