Hi Jon, Grant, On Sat, 28 Jun 2008 22:49:40 -0600, Grant Likely wrote: > On Sat, Jun 28, 2008 at 10:05:28PM -0400, Jon Smirl wrote: > > On 6/25/08, Jean Delvare <[EMAIL PROTECTED]> wrote: > > > > > > > > i2c->adap = mpc_ops; > > > > - i2c->adap.nr = pdev->id; > > > > i2c_set_adapdata(&i2c->adap, i2c); > > > > - i2c->adap.dev.parent = &pdev->dev; > > > > - if ((result = i2c_add_numbered_adapter(&i2c->adap)) < 0) { > > > > + i2c->adap.dev.parent = &op->dev; > > > > + > > > > + result = i2c_add_adapter(&i2c->adap); > > > > > > > > > The driver was previously using i2c_add_numbered_adapter(), giving MPC > > > platform the possibility to use new-style i2c drivers: > > > > > > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=1469fa263870acd890a4b9f6ef557acc5d673b44 > > > You're breaking this, I doubt it's on purpose? > > > > Grant, what do you want here? You're the one who converted it to > > i2c_add_numbered_adapter. But in other posts you've said that the > > device tree should have nothing to do with bus numbering. > > Yes, I did make that change, but that was when it was a platform bus > driver. Converting it to an of_platform bus driver entirely changes the > situation and it should go back to using i2c_add_adapter() with a parse > of the device tree for child nodes.
I am surprised and disappointed, as this sounds like a regression. Registering the i2c buses with random numbers and parsing the device tree later to figure out which devices are where, is what everybody was doing before the new i2c device/driver matching model was implemented, because there was no other way. I'm curious why you are going back to this approach when i2c-core now offers something way cleaner and more efficient. But well, you'll know better. I'm not familiar with the platform, and don't have the time to look into it anyway. > > Once this driver is converted to an OF one it shouldn't need bus ids > > since all of the i2c devices will be children of the bus node. We can > > just let the i2c subsystem assign a bus number. > > Exactly. > > > Timur has some issues with the i2c bus number in his ALSA driver. The > > problem is locating the i2c device when the i2s driver loads. Parsing > > the device tree to extract an i2c bus and device number is not a good > > solution. > > The trick here is to store the pointer to the device node inside the > i2c device. I do this with SPI devices like this: > > /* Store a pointer to the node in the device structure */ > of_node_get(nc); > spi->dev.archdata.of_node = nc; > > Then, when you've got a device_node pointer, you can parse through the > set of registered SPI devices and match against the one that has the > same device node pointer. > > > codec-handle should give you the i2c device node. But then we can't > > use of_find_device_by_node because the i2c device is not an of_device, > > it's a cross platform i2c_device. Should of_find_device_by_node() > > return a 'struct device' instead of a 'struct of_device' and leave it > > as a user exercise to cast up? It is used nine times in the kernel, > > mostly sparc. > > No, this doesn't work because I2C and SPI devices are not of_platform > devices. They aren't even platform devices. of_find_device_by_node() > only works for the of_platform bus. > > Using archdata.of_node is part of the device structure and works for > every bus type (platform, of_platform, SPI, I2C, PCI, etc.) -- Jean Delvare _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev