Re: [PATCH v4 1/2] ARM: dts: aspeed: Add KCS & lpc ctrl for Facebook

From: Vijay Khemka
Date: Thu Dec 13 2018 - 14:19:23 EST




ïOn 12/12/18, 5:04 PM, "Joel Stanley" <joel@xxxxxxxxx> wrote:

On Thu, 13 Dec 2018 at 07:34, Vijay Khemka <vijaykhemka@xxxxxx> wrote:
>
> Added kcs device and lpc ctrl device to enable LPC clock in Facebook
> Tiogapass device tree.

As we're going to re-spin, it's a good idea to have the KCS and LPC
changes in separate patches. I will take the KCS one straight away,
but the LPC one might need more work (see my comments below).

Thanks Joel,
I will create different patches and resubmit again.

>
> Signed-off-by: Vijay Khemka <vijaykhemka@xxxxxx>
> ---
> .../dts/aspeed-bmc-facebook-tiogapass.dts | 30 +++++++++++++++++++
> 1 file changed, 30 insertions(+)
>
> diff --git a/arch/arm/boot/dts/aspeed-bmc-facebook-tiogapass.dts b/arch/arm/boot/dts/aspeed-bmc-facebook-tiogapass.dts
> index d9d7f208788a..9544fa2c1822 100644
> --- a/arch/arm/boot/dts/aspeed-bmc-facebook-tiogapass.dts
> +++ b/arch/arm/boot/dts/aspeed-bmc-facebook-tiogapass.dts
> @@ -21,6 +21,18 @@
> memory@80000000 {
> reg = <0x80000000 0x20000000>;
> };
> +
> + reserved-memory {
> + #address-cells = <1>;
> + #size-cells = <1>;
> + ranges;
> +
> + flash_memory: region@98000000 {
> + no-map;
> + reg = <0x98000000 0x04000000>; /* 64M */
> + };

Are you using this to expose some RAM over LPC? If not, we don't want this here.
No, we are not using currently.

It is a flaw in the design of the driver that the reserved memory
region is required. We should change the driver to make it optional.
I agree with you we should make this change in driver.

As a workaround, we could add this patch to the tiogapass device tree
but make it smaller so you're not losing 64MB of RAM.
I will make it to 4K.

> + };
> +
> iio-hwmon {
> compatible = "iio-hwmon";
> oemname0 = "MB_P3V3";
> @@ -62,6 +74,12 @@
> };
> };
>
> +&lpc_ctrl {
> + status = "okay";
> + memory-region = <&flash_memory>;
> + flash = <&spi1>;
> +};
> +
> &uart1 {
> // Host Console
> status = "okay";
> @@ -75,6 +93,18 @@
> status = "okay";
> };
>
> +&kcs2 {
> + // BMC KCS channel 2
> + status = "okay";
> + kcs_addr = <0xca8>;
> +};
> +
> +&kcs3 {
> + // BMC KCS channel 3
> + status = "okay";
> + kcs_addr = <0xca2>;
> +};
> +
> &mac0 {
> status = "okay";
>
> --
> 2.17.1
>