Jonathan Cameron <jic23@xxxxxxxxxx> writes:
> On Fri, 18 Oct 2024 16:36:10 -0700
> Justin Weiss <justin@xxxxxxxxxxxxxxx> wrote:
>
>> Adds support for the Bosch BMI260 6-axis IMU to the Bosch BMI270
>> driver. Setup and operation is nearly identical to the Bosch BMI270,
>> but has a different chip ID and requires different firmware.
>>
>> Firmware is requested and loaded from userspace.
>>
>> Signed-off-by: Justin Weiss <justin@xxxxxxxxxxxxxxx>
> Trivial comments inline and a discussion on whether my earlier
> don't use an array comment makes sense in this particular case.
>
> Jonathan
>
>> ---
>> drivers/iio/imu/bmi270/bmi270.h | 1 +
>> drivers/iio/imu/bmi270/bmi270_core.c | 25 +++++++++++++++++++++++--
>> drivers/iio/imu/bmi270/bmi270_i2c.c | 13 +++++++++++++
>> drivers/iio/imu/bmi270/bmi270_spi.c | 8 ++++++++
>> 4 files changed, 45 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/iio/imu/bmi270/bmi270.h b/drivers/iio/imu/bmi270/bmi270.h
>> index 2e8d85a4e419..51e374fd4290 100644
>> --- a/drivers/iio/imu/bmi270/bmi270.h
>> +++ b/drivers/iio/imu/bmi270/bmi270.h
>> @@ -14,6 +14,7 @@ struct bmi270_data {
>> };
>>
>> enum bmi270_device_type {
>> + BMI260,
>> BMI270,
>> };
>>
>> diff --git a/drivers/iio/imu/bmi270/bmi270_core.c b/drivers/iio/imu/bmi270/bmi270_core.c
>> index 799df78ec862..b30201dc4e22 100644
>> --- a/drivers/iio/imu/bmi270/bmi270_core.c
>> +++ b/drivers/iio/imu/bmi270/bmi270_core.c
>> @@ -11,6 +11,8 @@
>> #include "bmi270.h"
>>
>> #define BMI270_CHIP_ID_REG 0x00
>> +#define BMI160_CHIP_ID_VAL 0xD1
>
> This one looks like a cut and paste error.
No, this was intentional -- I added the BMI160 chip ID here so it could
be checked later to avoid conflicting with the existing bmi160 driver. I
could add newlines before and after this group of _ID_VAL #defines if it
makes it clearer.
>> +#define BMI260_CHIP_ID_VAL 0x27
>> #define BMI270_CHIP_ID_VAL 0x24
>> #define BMI270_CHIP_ID_MSK GENMASK(7, 0)
>>
>> @@ -55,6 +57,7 @@
>> #define BMI270_PWR_CTRL_ACCEL_EN_MSK BIT(2)
>> #define BMI270_PWR_CTRL_TEMP_EN_MSK BIT(3)
>>
>> +#define BMI260_INIT_DATA_FILE "bmi260-init-data.fw"
>> #define BMI270_INIT_DATA_FILE "bmi270-init-data.fw"
>>
>> enum bmi270_scan {
>> @@ -67,6 +70,11 @@ enum bmi270_scan {
>> };
>>
>> const struct bmi270_chip_info bmi270_chip_info[] = {
>> + [BMI260] = {
>> + .name = "bmi260",
>> + .chip_id = BMI260_CHIP_ID_VAL,
>> + .fw_name = BMI260_INIT_DATA_FILE,
>> + },
>> [BMI270] = {
>> .name = "bmi270",
>> .chip_id = BMI270_CHIP_ID_VAL,
>> @@ -163,8 +171,21 @@ static int bmi270_validate_chip_id(struct bmi270_data *bmi270_device)
>> if (ret)
>> return dev_err_probe(dev, ret, "Failed to read chip id");
>>
>> - if (chip_id != BMI270_CHIP_ID_VAL)
>> - dev_info(dev, "Unknown chip id 0x%x", chip_id);
>> + /*
>> + * Some manufacturers use "BMI0160" for both the BMI160 and
>> + * BMI260. If the device is actually a BMI160, the bmi160
>> + * driver should handle it and this driver should not.
>> + */
>> + if (chip_id == BMI160_CHIP_ID_VAL)
>> + return -ENODEV;
This is where that BMI160 chip ID is checked.
>> +
>> + if (chip_id != bmi270_device->chip_info->chip_id)
>> + dev_info(dev, "Unexpected chip id 0x%x", chip_id);
>> +
>> + if (chip_id == BMI260_CHIP_ID_VAL)
>
> Ah. My argument on separate IDs means you'd have to do it this way whereas
> I was thinking maybe a loop would be a better idea. Ah well if we
> get a lot of supported chips, then we can rethink how to handle this.
> For now what you have here is fine and should deal with lack of appropriate
> ACPI ID mess.
I like the idea of separate structures, so I'll keep the if / else
here. I think it would be straightforward to change later without
conflicts if there are more supported chips.
I will change this to check against bmi260_chip_info.chip_id,
etc. instead of the constants, to make sure they stay consistent.
Justin
>> + bmi270_device->chip_info = &bmi270_chip_info[BMI260];
>> + else if (chip_id == BMI270_CHIP_ID_VAL)
>> + bmi270_device->chip_info = &bmi270_chip_info[BMI270];
>>
>> return 0;
>> }
