[RFC,v4,0/2] Add SDHC interconnect bandwidth scaling

Add interconnect bandwidths for SDHC driver using OPP framework that
is required by SDHC driver based on the clock frequency and bus width
of the card. Otherwise, the system clocks may run at minimum clock
speed and thus affecting the performance.

This change is based on
[RFC] mmc: host: sdhci-msm: Use the interconnect API
(https://lkml.org/lkml/2018/10/11/499) and

[PATCH v6] Introduce Bandwidth OPPs for interconnects
(https://lkml.org/lkml/2019/12/6/740)

Pradeep P V K (2):
  mmc: sdhci-msm: Add interconnect bus bandwidth scaling support
  dt-bindings: mmc: sdhci-msm: Add interconnect BW scaling strings

 .../devicetree/bindings/mmc/sdhci-msm.txt          |  18 ++
 drivers/mmc/host/sdhci-msm.c                       | 204 ++++++++++++++++++++-
 2 files changed, 218 insertions(+), 4 deletions(-)

--
changes from RFC v3 -> v4:
- Addressed review comments from Bjorn and Matthias
1.9.1

On Tue, 18 Feb 2020 18:30:33 +0530, Pradeep P V K wrote:
> Add interconnect bandwidth scaling supported strings for qcom-sdhci
> controller.
> 
> Signed-off-by: Pradeep P V K <ppvk@codeaurora.org>
> ---
> 
> changes from RFC v3 -> v4:
> - No changes.
> 
>  Documentation/devicetree/bindings/mmc/sdhci-msm.txt | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 

Acked-by: Rob Herring <robh@kernel.org>

On Tue 18 Feb 05:00 PST 2020, Pradeep P V K wrote:

> Add interconnect bandwidth scaling supported strings for qcom-sdhci
> controller.
> 
> Signed-off-by: Pradeep P V K <ppvk@codeaurora.org>

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

> ---
> 
> changes from RFC v3 -> v4:
> - No changes.
> 
>  Documentation/devicetree/bindings/mmc/sdhci-msm.txt | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
> index 7ee639b..cbe97b8 100644
> --- a/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
> +++ b/Documentation/devicetree/bindings/mmc/sdhci-msm.txt
> @@ -40,6 +40,21 @@ Required properties:
>  	"cal"	- reference clock for RCLK delay calibration (optional)
>  	"sleep"	- sleep clock for RCLK delay calibration (optional)
>  
> +Optional Properties:
> +* Following bus parameters are required for interconnect bandwidth scaling:
> +- interconnects: Pairs of phandles and interconnect provider specifier
> +		 to denote the edge source and destination ports of
> +		 the interconnect path.
> +
> +- interconnect-names: For sdhc, we have two main paths.
> +		1. Data path : sdhc to ddr
> +		2. Config path : cpu to sdhc
> +		For Data interconnect path the name supposed to be
> +		is "sdhc-ddr" and for config interconnect path it is
> +		"cpu-sdhc".
> +		Please refer to Documentation/devicetree/bindings/
> +		interconnect/ for more details.
> +
>  Example:
>  
>  	sdhc_1: sdhci@f9824900 {
> @@ -57,6 +72,9 @@ Example:
>  
>  		clocks = <&gcc GCC_SDCC1_APPS_CLK>, <&gcc GCC_SDCC1_AHB_CLK>;
>  		clock-names = "core", "iface";
> +		interconnects = <&qnoc MASTER_SDCC_ID &qnoc SLAVE_DDR_ID>,
> +				<&qnoc MASTER_CPU_ID &qnoc SLAVE_SDCC_ID>;
> +		interconnect-names = "sdhc-ddr","cpu-sdhc";
>  	};
>  
>  	sdhc_2: sdhci@f98a4900 {
> -- 
> 1.9.1
>