[RFC PATCH linux dev-4.13 1/3] soc: aspeed: Miscellaneous control interfaces

[Joel Stanley]

On 12 April 2018 at 13:21, Andrew Jeffery <andrew at aj.id.au> wrote:
> 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"

Do you mean bool or tristate? if you mean bool, drop the module-y bits below.

> +       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
> diff --git a/drivers/soc/aspeed/Makefile b/drivers/soc/aspeed/Makefile
> new file mode 100644
> index 000000000000..d1a80f9a584f
> --- /dev/null
> +++ b/drivers/soc/aspeed/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_ASPEED_BMC_MISC) += aspeed-bmc-misc.o
> diff --git a/drivers/soc/aspeed/aspeed-bmc-misc.c b/drivers/soc/aspeed/aspeed-bmc-misc.c
> new file mode 100644
> index 000000000000..48522a736a05
> --- /dev/null
> +++ b/drivers/soc/aspeed/aspeed-bmc-misc.c

copyright headahs

> @@ -0,0 +1,187 @@
> +#include <linux/kobject.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/mfd/syscon.h>
> +
> +#define DEVICE_NAME "aspeed-bmc-misc"

This is the name of our chardev? No, it appears to just be the driver
name. You can probably just use it directly.

An observation: It's the only thing inside this file that is aspeed
specific. If not for the name, it could be generic code.

lgtm. I suggest writing up some bindings and putting on the asbestos pants.

I'll merge this into openbmc with the IBM copyright added to the top.
With this adding userspace ABI, anyone who writes code against it will
need to make themselves available for rework as it goes through
upstream review.

Cheers,

Joel