Hi Jagan, On 9 October 2014 04:33, Jagan Teki <jagannadh.t...@gmail.com> wrote: > On 9 October 2014 02:03, Simon Glass <s...@chromium.org> wrote: >> Hi, >> >> On 29 September 2014 13:34, 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, even at a subsystem level, is never going to work. >>> >>> 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 assist with the conversion of other SPI drivers, a README file is >>> added to walk through the process. >>> >>> So far, sandbox, exynos and tegra drivers are converted over. >>> >>> As always, driver model patches are available at u-boot-dm.git branch >>> 'working'. There is a branch for just this series called 'spi-working'. >> >> I think this has had enough time out there. So I will push this to >> dm/next later this week. > > Sorry - I need to review a lot wrt v3. > I do understand that it has been in enough time, but this causes a > significant changes on > entire framework, please hold on for a while I need to think with > respect on qspi stuff with in > the spi framework.
Well I'm not sure it supports setting of the flags that are needed for that. I don't have a platform to test with anyway. On the other hand adding that support to driver model could easily be a separate effort. I don't see a good reason to hold up the core SPI / SPI flash support. Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot