[U-Boot] [PATCH V5 3/7] ARM: omap-common: Add standard access for board description EEPROM

Tom Rini trini at konsulko.com
Fri Feb 26 19:17:13 CET 2016


On Wed, Feb 24, 2016 at 12:30:54PM -0600, Steve Kipisz wrote:

> From: Lokesh Vutla <lokeshvutla at ti.com>
> 
> Several TI EVMs have EEPROM that can contain board description information
> such as revision, DDR definition, serial number, etc. In just about all
> cases, these EEPROM are on the I2C bus and provides us the opportunity
> to centralize the generic operations involved.
> 
> The on-board EEPROM on the BeagleBone Black, BeagleBone, AM335x EVM,
> AM43x GP EVM, AM57xx-evm, BeagleBoard-X15 share the same format.
> However, DRA-7* EVMs, OMAP4SDP use a modified format.
> 
> We hence introduce logic which is generic between these platforms
> without enforcing any specific format. This allows the boards to use the
> relevant format for operations that they might choose.
> 
> This module will compile for all TI SoC based boards when
> CONFIG_TI_I2C_BOARD_DETECT is enabled to have optimal build times for
> platforms that require this support.
> 
> It is important to note that this logic is fundamental to the board
> configuration process such as DDR configuration which is needed in
> SPL, hence cannot be part of the standard u-boot driver model (which
> is available later in the process). Hence, to aid efficiency, the
> eeprom contents are copied over to SRAM scratchpad memory area at the
> first invocation to retrieve data.
> 
> To prevent churn with cases such as DRA7, where eeprom format maybe
> incompatible, we introduce a generic common format in eeprom which
> is made available over accessor functions for usage.
> 
> Special handling for BBG1 EEPROM had to be introduced thanks to the
> weird eeprom rev contents used.
> 
> The follow on patches introduce the use of this library for AM335x,
> AM437x, and AM57xx.
> 
> Signed-off-by: Lokesh Vutla <lokeshvutla at ti.com>
> Signed-off-by: Steve Kipisz <s-kipisz2 at ti.com>
> Signed-off-by: Roger Quadros <rogerq at ti.com>
> Signed-off-by: Nishanth Menon <nm at ti.com>

Reviewed-by: Tom Rini <trini at konsulko.com>

-- 
Tom
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