On Mon, 02 Jun 2014, Wolfram Sang wrote: > On Mon, Jun 02, 2014 at 02:16:59PM +0200, Linus Walleij wrote: > > On Sat, May 31, 2014 at 3:48 PM, Wolfram Sang <wsa@xxxxxxxxxxxxx> wrote: > > > > > >> Right, I read the function which provides the functionality, but my > > >> point is; I don't think my patch changes the semantics in a way which > > >> would adversely affect this option. If you think that it does, can you > > >> specify how please? > > > > > > Currently, if a driver would be DT only and does not provide a seperate > > > i2c_device_id table, then the driver is unusable with method 4. I don't > > > like to have some drivers being capable of it and some not. > > > > > >> Does the sysfs method create a i2c_device_id table? If not, how does > > >> it probe successfully pre-patch? > > > > > > The sysfs method creates a device. Its name is matched against > > > i2c_device_ids only since it does not have a node pointer for DT to be > > > matched against. > > > > Is this really so useful on embedded systems? > > Well, this feature is at least nice with embedded: > > --- > > * You are developing a driver on a test board, where you soldered the I2C > device yourself. > > --- > > Or during HW bringup, you this or that driver for a device (out-of-tree > vs. in-kernel), and hey, the RTC even has an EEPROM at another address, > let's try. Such things are the use cases I have mostly seen and those > customers liked it. > > The problem is that we are talking about matching against I2C slave > drivers. I can't see a line between embedded and non-embedded when it > comes to slaves. They are just slaves and could be on any hardware. > Keeping the bigger picture in mind, IMO it is cumbersome if some drivers > support user-space instantiation and some not. > > Though, I wouldn't mind if compatible entries could be passed to the > 'new_device' file, in addition to i2c_device_ids. Yet, this needs some > extra handling I haven't found the time for, yet. Actually, I'm just about to submit a new set. Hopefully we cover some bases. -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
