[U-Boot] [PATCH v4 2/4] aspeed: Add basic ast2500-specific drivers and configuration

[Simon Glass]

On 18 January 2017 at 14:44, Maxim Sloyko <maxims at google.com> wrote:
> Clock Driver
>
> This driver is ast2500-specific and is not compatible with earlier
> versions of this chip. The differences are not that big, but they are
> in somewhat random places, so making it compatible with ast2400 is not
> worth the effort at the moment.
>
> SDRAM MC driver
>
> The driver is very ast2500-specific and is completely incompatible
> with previous versions of the chip.
>
> The memory controller is very poorly documented by Aspeed in the
> datasheet, with any mention of the whole range of registers missing. The
> initialization procedure has been basically taken from Aspeed SDK, where
> it is implemented in assembly. Here it is rewritten in C, with very limited
> understanding of what exactly it is doing.
>
> ---
>
> Changes in v4:
> - Expanded AST2500 EVB description in Kconfig
> - Added docstrings for ast_get_clk() and ast_get_scu()
> - Fixed include file ordering
> - Added docstring for ast2500_get_uart_clk_rate
> - Use dev_get_addr_ptr
> - Use WDT helper function to reset memory controller
>
> Changes in v3: None
> Changes in v2: None
> Changes in v1:
> - Merge together all patches related to ast2500 specific drivers
> - Add Copyright statement to all c/h files
> - Use DT include from Linux Kernel, Add U-Boot specific modifications in
>   ast2500-u-boot.dtsi
>
>
> Reviewed-by: Tom Rini <trini at konsulko.com>
>
> Signed-off-by: Maxim Sloyko <maxims at google.com>
> ---
>  arch/arm/dts/ast2500-u-boot.dtsi                 |  53 +++
>  arch/arm/dts/ast2500.dtsi                        | 174 +++++++++
>  arch/arm/include/asm/arch-aspeed/scu_ast2500.h   | 125 +++++++
>  arch/arm/include/asm/arch-aspeed/sdram_ast2500.h | 138 ++++++++
>  arch/arm/mach-aspeed/Kconfig                     |   2 +
>  arch/arm/mach-aspeed/Makefile                    |   1 +
>  arch/arm/mach-aspeed/ast2500/Kconfig             |  14 +
>  arch/arm/mach-aspeed/ast2500/Makefile            |   1 +
>  arch/arm/mach-aspeed/ast2500/clk_ast2500.c       |  30 ++
>  arch/arm/mach-aspeed/ast2500/sdram_ast2500.c     | 432 +++++++++++++++++++++++
>  drivers/clk/Makefile                             |   2 +
>  drivers/clk/aspeed/Makefile                      |   7 +
>  drivers/clk/aspeed/clk_ast2500.c                 | 265 ++++++++++++++
>  include/dt-bindings/clock/ast2500-scu.h          |  29 ++
>  14 files changed, 1273 insertions(+)
>  create mode 100644 arch/arm/dts/ast2500-u-boot.dtsi
>  create mode 100644 arch/arm/dts/ast2500.dtsi
>  create mode 100644 arch/arm/include/asm/arch-aspeed/scu_ast2500.h
>  create mode 100644 arch/arm/include/asm/arch-aspeed/sdram_ast2500.h
>  create mode 100644 arch/arm/mach-aspeed/ast2500/Kconfig
>  create mode 100644 arch/arm/mach-aspeed/ast2500/Makefile
>  create mode 100644 arch/arm/mach-aspeed/ast2500/clk_ast2500.c
>  create mode 100644 arch/arm/mach-aspeed/ast2500/sdram_ast2500.c
>  create mode 100644 drivers/clk/aspeed/Makefile
>  create mode 100644 drivers/clk/aspeed/clk_ast2500.c
>  create mode 100644 include/dt-bindings/clock/ast2500-scu.h

Reviewed-by: Simon Glass <sjg at chromium.org>

A few nits for later:

I think it is better to define a shifted mask:

#define SDRAM_REFRESH_PERIOD_SHIFT     8
#define SDRAM_REFRESH_PERIOD_MASK      (0xf << SDRAM_REFRESH_PERIOD_SHIFT)

What is CONFIG_DUALX8_RAM for? Can this be encoded in the device tree?

Regards,
Simon