On Thu, 2022-07-21 at 16:15 +0100, Daniele Alessandrelli wrote: > Hi Bryan, > > On Mon, 2022-07-18 at 02:42 +0100, Bryan O'Donoghue wrote: > > V2: > > Sakari wasn't especially satisfied with the answer imx412 and imx577 have > > the same init sequence but, suggested setting the string for imx577 as is > > done in the ccs driver. > > > > https://lore.kernel.org/all/20220607134057.2427663-3-bryan.odonoghue@xxxxxxxxxx/t/ > > > > I went to look at that and asked myself "how would I tell the difference > > between the two silicon parts". The obvious answer is a chip identifier. > > > > Luckily this class of IMX sensor has a chip identifier at offset 0x0016. > > > > That looks like this for imx258, imx319 and imx355 > > > > drivers/media/i2c/imx258.c:#define IMX258_REG_CHIP_ID 0x0016 > > drivers/media/i2c/imx258.c:#define IMX258_CHIP_ID 0x0258 > > > > drivers/media/i2c/imx319.c:#define IMX319_REG_CHIP_ID 0x0016 > > drivers/media/i2c/imx319.c:#define IMX319_CHIP_ID 0x0319 > > > > drivers/media/i2c/imx355.c:#define IMX355_REG_CHIP_ID 0x0016 > > drivers/media/i2c/imx355.c:#define IMX355_CHIP_ID 0x0355 > > > > but then looks like this for imx412. > > > > drivers/media/i2c/imx412.c:#define IMX412_REG_ID 0x0016 > > drivers/media/i2c/imx412.c:#define IMX412_ID 0x577 > > > > This made no sense at all to me, why is the imx412 driver not named imx577 ? > > I tried to reached out to the colleagues who wrote the driver but it > seems they are not in the company anymore. > > However, I managed to get the imx412 register map documentation they > used while developing the driver and the value at offset 0x0016 is > reported to be 0x0577. > > I agree this is strange, so, next week, I'll try to see if I can get my > hands on an imx412 sensor to verify the value reported by the HW. I managed to get one of the imx412 sensors that were used for the development of this driver and I can confirm that the CHIP ID reported by the HW is 0x577 (as specified in the datasheet I was given) However, somebody [1] on the internet is reporting that their imx412 shows a different ID, so it's possible that different batches of imx412 have different IDs (perhaps Sony fixed the ID inconsistency at some point). But I'd like to see more evidence of this. [1] https://discuss.96boards.org/t/imx412-driver-troubleshooting/11350 Anyway, regardless of the ID, I think this driver shouldn't be renamed because it was written for imx412, using an imx412. If there exist other imx412 devices with a different ID, I think we should just add support for that ID to the driver. > > In the meantime, would you be able to check what 16-bit value the > imx577 sensor reports at offset 0x0000 (which, on some IMX models, > seems to be another ID register)? > > > > > I went and dug into the Qualcomm camx/chi-cdk sources to find that a file > > called cmk_imx577_sensor.xml has a property called sensorId which is > > constrained to 0x0577. > > > > In the Qualcomm stack this pairing of filename and identifier is > > maintained for imx258, imx376, imx476, imx576, imx519, imx362, imx481, > > imx318 imx334 and imx386. > > > > Every single example I can find of a Sony IMX sensor which returns a chip > > identifier at offset 0x0016 matches the driver name to the returned sensor > > id both here upstream in Linux and in Qualcomm's camx stack. > > > > The conclusion I draw from this is that imx412.c is inappropriately named. > > > > I think the right thing to do is to rename imx412 to imx577. It is > > confusing and I think wrong to pair imx412.c with a chip which identifies > > as 0x0577. > > > > V1: > > Right now the imx412 and imx577 are code and pin compatible however, they > > are distinct pieces of silicon. > > > > Document imx577 as a compatible enum and add the compat string to imx412.c. > > This allows us to differentiate these chips in DTS and potentially to apply > > any future imx412 or imx577 specific changes appropriately. > > > > Bryan O'Donoghue (3): > > media: dt-bindings: media: Rename imx412 to imx577 > > media: i2c: imx577: Rename imx412.c to imx577.c > > media: i2c: imx577: Fix chip identifier define name > > > > .../{sony,imx412.yaml => sony,imx577.yaml} | 18 +- > > MAINTAINERS | 6 +- > > drivers/media/i2c/Kconfig | 8 +- > > drivers/media/i2c/Makefile | 2 +- > > drivers/media/i2c/{imx412.c => imx577.c} | 622 +++++++++--------- > > 5 files changed, 328 insertions(+), 328 deletions(-) > > rename Documentation/devicetree/bindings/media/i2c/{sony,imx412.yaml => sony,imx577.yaml} (83%) > > rename drivers/media/i2c/{imx412.c => imx577.c} (55%) > > >
