Hi, On 14 July 2014 18:56, Simon Glass <s...@chromium.org> wrote: > Up until now driver model has not been used for any type of bus. Buses > have some unique properties and needs, so we cannot claim that driver > model can cover all the common cases unless we have converted a bus over > to driver model. > > SPI is a reasonable choice for this next step. It has a fairly simple > API and not too many dependencies. The main one is SPI flash so we may > as well convert that also. Since the boards I test with have cros_ec I > have also included that, for SPI only. > > The technique used is make use of driver model's supported data structures > to hold information currently kept by each subsystem in a private data > structure. Since 'struct spi_slave' relates to the slave device on the bus > it is stored in the 'parent' data with each child device of the bus. > Since 'struct spi_flash' is a standard interface used for each SPI flash > driver, it is stored in the SPI FLash uclass's private data for each > device. > > New defines are created to enable driver model for each subsystem. These > are: > > CONFIG_DM_SPI > CONFIG_DM_SPI_FLASH > CONFIG_DM_CROS_EC > > This allows us to move some boards and drivers to driver model, while > leaving others behind. A 'big bang' conversion of everything to driver > model, event at a subsystem level, is never going to work. > > On the other hand, we change the driver at the same time as the CONFIG > option is enabled. Keeping both version of the driver around involves a > flock of #ifdefs, the benefit of which is not apparent to me, since the > old code is removed anyway. > > There is some cost in changing the uclass interface after it is created, > so if you have limited time, please spend it reviewing the uclass > interfaces in spi.h and spi_flash.h. These need to be supported by each > driver, so changing them later may involve changing multiple drivers. > > To help with conversion of SPI drivers to driver model, documentation is > provided which takes the happy camper through the process with an example. > > As always, driver model patches are available at u-boot-dm.git branch > 'working'. > > Note: This series is not fully ready - e.g. some header files are missing > comments. But I wanted to get it out for review early since some SPI work > is ongoing which might depend on it.
Are there any comments on this series please? I'd like to apply these to dm/master early next week, excluding the exynos ones. Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
