[U-Boot] [PATCH 2/6] sf: Optimize flash features code

[Marek Vasut <marex@denx.de>]

On Saturday, January 18, 2014 at 09:06:29 PM, Jagannadha Sutradharudu Teki 
wrote:
> - Shrink spi_slave {}
> - Shrink spi_flash_params {}
> - Documentation for sf features
> 
> Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
> Cc: Marek Vasut <marex@denx.de>
> ---
>  doc/SPI/README.sf-features    | 122 ++++++++++++++++++++++++++++++
>  drivers/mtd/spi/sf.c          |   4 +-
>  drivers/mtd/spi/sf_internal.h |   1 -
>  drivers/mtd/spi/sf_ops.c      |   8 +-
>  drivers/mtd/spi/sf_params.c   | 172
> +++++++++++++++++++++--------------------- drivers/mtd/spi/sf_probe.c    |
>  71 ++++++++---------
>  include/spi.h                 |  42 ++++-------
>  include/spi_flash.h           |  24 +++---
>  8 files changed, 270 insertions(+), 174 deletions(-)
>  create mode 100644 doc/SPI/README.sf-features
> 
> diff --git a/doc/SPI/README.sf-features b/doc/SPI/README.sf-features
> new file mode 100644
> index 0000000..d35f56d
> --- /dev/null
> +++ b/doc/SPI/README.sf-features
> @@ -0,0 +1,122 @@
> +SPI FLASH feature enhancements:
> +==============================
> +
> +This document describes how to extend the current data structures in spi
> subsystem +for making use of new flash features/operations w.r.t to
> controller driver support. +
> +1. spi_slave:
> +
> +struct spi_slave {
> +    ..........
> +    u32 mode_bits;
> +    ........
> +};
> +
> + at mode_bits can be used to expose the SPI RX/TX operation modes, bus
> options and +few flags which are used to extended the flash specific
> features/operations +- include/spi.h
> +
> +mode_bits:
> +- SPI_TX_QPP: 4-Wire tx transfer operation quad page program
> +- SPI_RX_SLOW: 1-wire rx transfer operation array slow read
> +- SPI_RX_DUAL: 2-wire rx transfer operation dual fast read
> +- SPI_RX_DUAL_IO: 2-wire rx transfer operation dual io fast read
> +- SPI_RX_QUAD: 4-wire rx transfer operation quad fast read
> +- SPI_RX_QUAD_IO: 4-wire rx transfer operation quad io fast read
> +- SPI_SHARED: dual flash devices are connected in shared bus connection
> +- SPI_SEPARATED: dual flash devices are connected in separate bus
> connection +- SPI_U_PAGE: select the upper flash in dual flash shared bus
> connection [1] +

A generic SPI controller _does_ _not_ _care_ about any SPI flash crud. The SPI 
bus controller (which is what this is for) and SPI-NOR controller are two 
different things and must have two different slave structures.