[U-Boot] [PATCH v5 010/101] x86: spi: Add helper functions for Intel Fast SPI

[Bin Meng]

On Mon, Nov 25, 2019 at 12:11 PM Simon Glass <sjg at chromium.org> wrote:
>
> Most x86 CPUs use a mechanism where the SPI flash is mapped into the very
> top of 32-bit address space, so that it can be executed in place and read
> simply by copying from memory. For an 8MB ROM the mapping starts at
> 0xff800000.
>
> However some recent Intel CPUs do not use a simple 1:1 memory map. Instead
> the map starts at a different address and not all of the SPI flash is
> accessible through the map. This 'Fast SPI' feature requires that U-Boot
> check the location of the map. It is also possible (optionally) to read
> from the SPI flash using a driver.
>
> Add support for booting from Fast SPI. The memory-mapped version is used
> by both TPL and SPL on Apollo Lake.
>
> In respect of a SPI flash driver, the actual SPI driver is ich.c - this
> just adds a few helper functions and definitions.
>
> This is used by Apollo Lake.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
>
> Changes in v5: None
> Changes in v4: None
> Changes in v3:
> - Add support for of-platdata for TPL
> - Add the missing header file
> - Change Fast-SPI driver into a helper file used by ICH SPI
> - Don't include write() and erase() in TPL
> - Drop 'a4' comment for register offset
> - Merge in patch "x86: Add support for booting from Fast SPI"
> - Reorder file so that write() and erase() are together
> - Use pci_get_devfn()
>
> Changes in v2: None
>
>  arch/x86/cpu/intel_common/Makefile   |  1 +
>  arch/x86/cpu/intel_common/fast_spi.c | 73 ++++++++++++++++++++++++++++
>  arch/x86/include/asm/fast_spi.h      | 68 ++++++++++++++++++++++++++
>  arch/x86/include/asm/spl.h           |  1 +
>  4 files changed, 143 insertions(+)
>  create mode 100644 arch/x86/cpu/intel_common/fast_spi.c
>  create mode 100644 arch/x86/include/asm/fast_spi.h
>

Reviewed-by: Bin Meng <bmeng.cn at gmail.com>