openbmc Digest, Vol 32, Issue 32

[Wang, Haiyue]

Hi Andrew,

Facebook uses the 'devmem' utility and python script to implement the 
soc register

read and write in a simple way. And the yocto layer is also very clear 
like different

chip vendor and common parts.


Kernel device tree upstream is also very slow, we needs two parts 
(device tree + user app)

to finish the soc setting. But Facebook just uses user app, this 
development is fast, and

simple is the best.


Well, just for sharing what I found, I may misunderstood the BIG idea 
after this kernel

patch design. :-)


soc_gpio_table = {

	'A10': [

	Function('SDA3', BitsEqual(0x90, [16], 0x1)),

	Function('GPIOQ1', None)

	],

	'A11': [

	Function('SCL3', BitsEqual(0x90, [16], 0x1)),

	Function('GPIOQ0', None)

	],

https://github.com/facebook/openbmc/blob/helium/common/recipes-utils/openbmc-gpio/files/openbmc-gpio-1/phymemory.py

https://github.com/facebook/openbmc/blob/helium/meta-aspeed/recipes-utils/ast-mdio/files/ast-mdio.py

https://github.com/facebook/openbmc/blob/helium/meta-aspeed/recipes-utils/openbmc-gpio/files/openbmc-gpio-1/ast2500_gpio_table.py


BR,

Haiyue


On 2018-04-12 13:32, openbmc-request at lists.ozlabs.org wrote:
> Message: 1
> Date: Thu, 12 Apr 2018 13:21:43 +0930
> From: Andrew Jeffery<andrew at aj.id.au>
> To:openbmc at lists.ozlabs.org
> Cc: Andrew Jeffery<andrew at aj.id.au>,joel at jms.id.au,jk at ozlabs.org,
> 	benh at kernel.crashing.org
> Subject: [RFC PATCH linux dev-4.13 1/3] soc: aspeed: Miscellaneous
> 	control interfaces
> Message-ID:<20180412035145.21488-2-andrew at aj.id.au>
>
> The ASPEED BMC SoCs have many knobs and switches that are sometimes
> design-specific and often defy any approach to unify them under an
> existing subsystem.
>
> Add a driver to translate a devicetree table into sysfs entries to
> expose bits and fields for manipulation from userspace. This encompasses
> concepts from scratch registers to boolean conditions to enable or
> disable host interface features.
>
> Signed-off-by: Andrew Jeffery<andrew at aj.id.au>
> ---
>   drivers/soc/Kconfig                  |   1 +
>   drivers/soc/Makefile                 |   1 +
>   drivers/soc/aspeed/Kconfig           |  11 +++
>   drivers/soc/aspeed/Makefile          |   1 +
>   drivers/soc/aspeed/aspeed-bmc-misc.c | 187 +++++++++++++++++++++++++++++++++++
>   5 files changed, 201 insertions(+)
>   create mode 100644 drivers/soc/aspeed/Kconfig
>   create mode 100644 drivers/soc/aspeed/Makefile
>   create mode 100644 drivers/soc/aspeed/aspeed-bmc-misc.c
>
> diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
> index 07fc0ac51c52..776fd5978f70 100644
> --- a/drivers/soc/Kconfig
> +++ b/drivers/soc/Kconfig
> @@ -1,6 +1,7 @@
>   menu "SOC (System On Chip) specific Drivers"
>   
>   source "drivers/soc/actions/Kconfig"
> +source "drivers/soc/aspeed/Kconfig"
>   source "drivers/soc/atmel/Kconfig"
>   source "drivers/soc/bcm/Kconfig"
>   source "drivers/soc/fsl/Kconfig"
> diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
> index 9241125416ba..94a5b97c4466 100644
> --- a/drivers/soc/Makefile
> +++ b/drivers/soc/Makefile
> @@ -3,6 +3,7 @@
>   #
>   
>   obj-$(CONFIG_ARCH_ACTIONS)	+= actions/
> +obj-$(CONFIG_ARCH_ASPEED)       += aspeed/
>   obj-$(CONFIG_ARCH_AT91)		+= atmel/
>   obj-y				+= bcm/
>   obj-$(CONFIG_ARCH_DOVE)		+= dove/
> diff --git a/drivers/soc/aspeed/Kconfig b/drivers/soc/aspeed/Kconfig
> new file mode 100644
> index 000000000000..704a4efe180f
> --- /dev/null
> +++ b/drivers/soc/aspeed/Kconfig
> @@ -0,0 +1,11 @@
> +menu "ASPEED SoC drivers"
> +
> +config ASPEED_BMC_MISC
> +	bool "Miscellaneous ASPEED BMC interfaces"
> +	depends on ARCH_ASPEED || COMPILE_TEST
> +	default ARCH_ASPEED
> +	help
> +	  Say yes to expose VGA and LPC scratch registers, and other
> +	  miscellaneous control interfaces specific to the ASPEED BMC SoCs
> +
> +endmenu