From mboxrd@z Thu Jan  1 00:00:00 1970
From: Matthias Kaehlcke <mka@chromium.org>
Subject: Re: [PATCH V2 7/8] spi: spi-qcom-qspi: Add interconnect support
Date: Fri, 13 Mar 2020 17:58:17 -0700
Message-ID: <20200314005817.GN144492@google.com>
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 <1584105134-13583-8-git-send-email-akashast@codeaurora.org>
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To: Akash Asthana <akashast@codeaurora.org>
Cc: gregkh@linuxfoundation.org, agross@kernel.org, bjorn.andersson@linaro.org, wsa@the-dreams.de, broonie@kernel.org, mark.rutland@arm.com, robh+dt@kernel.org, linux-i2c@vger.kernel.org, linux-spi@vger.kernel.org, devicetree@vger.kernel.org, swboyd@chromium.org, mgautam@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-serial@vger.kernel.org, dianders@chromium.org, evgreen@chromium.org
List-Id: linux-i2c@vger.kernel.org

Hi,

On Fri, Mar 13, 2020 at 06:42:13PM +0530, Akash Asthana wrote:
> Get the interconnect paths for QSPI device and vote according to the
> current bus speed of the driver.
> 
> Signed-off-by: Akash Asthana <akashast@codeaurora.org>
> ---
>  - As per Bjorn's comment, introduced and using devm_of_icc_get API for getting
>    path handle
>  - As per Matthias comment, added error handling for icc_set_bw call
> 
>  drivers/spi/spi-qcom-qspi.c | 46 ++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 45 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/spi-qcom-qspi.c b/drivers/spi/spi-qcom-qspi.c
> index 3c4f83b..ad48f43 100644
> --- a/drivers/spi/spi-qcom-qspi.c
> +++ b/drivers/spi/spi-qcom-qspi.c
> @@ -2,6 +2,7 @@
>  // Copyright (c) 2017-2018, The Linux foundation. All rights reserved.
>  
>  #include <linux/clk.h>
> +#include <linux/interconnect.h>
>  #include <linux/interrupt.h>
>  #include <linux/io.h>
>  #include <linux/module.h>
> @@ -139,7 +140,10 @@ struct qcom_qspi {
>  	struct device *dev;
>  	struct clk_bulk_data *clks;
>  	struct qspi_xfer xfer;
> -	/* Lock to protect xfer and IRQ accessed registers */
> +	struct icc_path *icc_path_cpu_to_qspi;
> +	unsigned int avg_bw_cpu;
> +	unsigned int peak_bw_cpu;

This triplet is a recurring pattern, and is probably not limited to geni SE/QSPI.
On https://patchwork.kernel.org/patch/11436889/#23221925 I suggested the creation
of a geni SE specific struct, however adding a generic convenience struct to
'linux/interconnect.h' might be the better solution:

struct icc_client {
	struct icc_path *path;
	unsigned int avg_bw;
	unsigned int peak_bw;
};

I'm sure there are better names for it, but this would be the idea.