[U-Boot] [PATCH v3 0/26] dm: Add additional bus functionality

[Masahiro Yamada]

Hi Simon,



On Sun, 25 Jan 2015 08:26:54 -0700
Simon Glass <sjg at chromium.org> wrote:

> The current bus implementation is simple but leaves some things to drivers
> which are better handled in the uclass.
> 
> At present uclasses cannot provide a common way of dealing with children
> (i.e. devices on the bus), so we have duplication in the drivers. The same
> code is repeated in each driver when it would be better to put it in the
> uclass.
> 
> Secondly, we don't have the concept of per-child platform data for devices
> on the bus. Instead the per-child data can only exist when the child is
> actually probed. This is not really suitable. Examples of things we want to
> know before a child is probed are:
> 
>    - chip address (for I2C)
>    - chip select (for SPI)
>    - device address (for PCI)
> 
> These things are static and do not change when the device is probed and
> removed. In some cases (such as SPI mode and maximum speed), the data may
> be copied to run-time data when the device is probed. It may then be changed
> while the driver is active, but the original platform data is never changed
> by drivers once it is set up.
> 
> To address these issues, additional functions are added:
> 
> - per-child platform data, which can be defined by the uclass and (if
> necessary) overriden by the bus driver. This allows the bus's uclass to
> provide some consistency here
> - per-child post-bind and pre-probe methods in the uclass. These allow the
> bus uclass to set up the per-child platform data, and also to do any
> last-minute adjustments before the child is probed.
> 
> With these changes, some code can be removed from the existing I2C and SPI
> drivers and this has been done as part of this series.
> 
> With this series I2C and SPI are tested on:
> - jetson-tk1 (Tegra 124)
> - beaver (Tegra 30)
> - seaboard (Tegra 20, I2C only)
> - trimslice (Tegra 20, SPI only)
> - snow (Exynos 5250)
> - pit (Exynos 5420, note I2C probe is previously broken)
> - link (x86)
> - sandbox
> 
> Note: Some of these changes were previously included in the DM PCI RFC. This
> series is available at u-boot-dm/i2c-working.
> 
> Changes in v3:
> - Add missing 'static' to two functions
> - Change variable name from parent_drv to uc_drv
> - Fix comment to say 'node references' instead of 'phandles'
> - Fix stale comment in device_probe_child()
> - Fix typo in commit subject
> - Remove unnecessary check that dev->parent_platdata is NULL
> - Remove unnecessary per_child_auto_alloc_size value


I issued my Reviewed-by to some rest of the patches.

V3 looks good enough to be applied.  Thank you!


Best Regards
Masahiro Yamada