Re: [PATCH v3 2/4] iio: accel: add the new entry in driver for fxls8967af

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 14/12/2022 10:32, Jonathan Cameron wrote:
> On Tue, 13 Dec 2022 19:53:30 +0100
> Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> wrote:
> 
>> On 13/12/2022 18:15, Han Xu wrote:
>>> Add this new device entry in the driver id table.
>>>
>>> Signed-off-by: Han Xu <han.xu@nxp.com>
>>>
>>> ---
>>> changes in v2
>>> - change chip info orders
>>> ---
>>>  drivers/iio/accel/fxls8962af-core.c | 7 +++++++
>>>  drivers/iio/accel/fxls8962af-i2c.c  | 2 ++
>>>  drivers/iio/accel/fxls8962af.h      | 1 +
>>>  3 files changed, 10 insertions(+)
>>>
>>> diff --git a/drivers/iio/accel/fxls8962af-core.c b/drivers/iio/accel/fxls8962af-core.c
>>> index 98811e4e16bb..c3589c3084ee 100644
>>> --- a/drivers/iio/accel/fxls8962af-core.c
>>> +++ b/drivers/iio/accel/fxls8962af-core.c
>>> @@ -127,6 +127,7 @@
>>>  #define FXLS8962AF_DEVICE_ID			0x62
>>>  #define FXLS8964AF_DEVICE_ID			0x84
>>>  #define FXLS8974CF_DEVICE_ID			0x86
>>> +#define FXLS8967AF_DEVICE_ID			0x87
>>>  
>>>  /* Raw temp channel offset */
>>>  #define FXLS8962AF_TEMP_CENTER_VAL		25
>>> @@ -765,6 +766,12 @@ static const struct fxls8962af_chip_info fxls_chip_info_table[] = {
>>>  		.channels = fxls8962af_channels,
>>>  		.num_channels = ARRAY_SIZE(fxls8962af_channels),
>>>  	},
>>> +	[fxls8967af] = {
>>> +		.chip_id = FXLS8967AF_DEVICE_ID,
>>> +		.name = "fxls8967af",
>>> +		.channels = fxls8962af_channels,
>>> +		.num_channels = ARRAY_SIZE(fxls8962af_channels),
>>> +	},
>>>  	[fxls8974cf] = {
>>>  		.chip_id = FXLS8974CF_DEVICE_ID,
>>>  		.name = "fxls8974cf",
>>> diff --git a/drivers/iio/accel/fxls8962af-i2c.c b/drivers/iio/accel/fxls8962af-i2c.c
>>> index 17dd56756ff9..a8944b255a28 100644
>>> --- a/drivers/iio/accel/fxls8962af-i2c.c
>>> +++ b/drivers/iio/accel/fxls8962af-i2c.c
>>> @@ -30,6 +30,7 @@ static int fxls8962af_probe(struct i2c_client *client)
>>>  static const struct i2c_device_id fxls8962af_id[] = {
>>>  	{ "fxls8962af", fxls8962af },
>>>  	{ "fxls8964af", fxls8964af },
>>> +	{ "fxls8967af", fxls8967af },
>>>  	{ "fxls8974cf", fxls8974cf },
>>>  	{}
>>>  };
>>> @@ -38,6 +39,7 @@ MODULE_DEVICE_TABLE(i2c, fxls8962af_id);
>>>  static const struct of_device_id fxls8962af_of_match[] = {
>>>  	{ .compatible = "nxp,fxls8962af" },
>>>  	{ .compatible = "nxp,fxls8964af" },
>>> +	{ .compatible = "nxp,fxls8967af" },
>>>  	{ .compatible = "nxp,fxls8974cf" },  
>>
>> This is confusing. The I2C ID table has driver data, but OF ID table
>> hasn't. So are they compatible or not?
> 
> Due to some evilness in i2c that 'works' as long as the two arrays have
> matching entries.  As a general rule we prefer to have the data in both, check
> the firmware table first and only then fallback to i2c_device_id data on the
> basis it is less fragile.
> 
> The evilness in i2c is that the search for match data will use the dt compatible
> stripped of the vendor prefix and string match that against the i2c_device_id table.
> 
> Nice to clean this up, but not necessarily in this series (fine if it is though!)

OK, so in fact devices are not fully compatible - I got mislead by OF
table. I'll comment in bindings about it.

Best regards,
Krzysztof