Re: [PATCH V7 6/7] spi: spi-qcom-qspi: Add interconnect support

[Matthias Kaehlcke <mka@xxxxxxxxxxxx>]

On Tue, May 26, 2020 at 06:24:49PM +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@xxxxxxxxxxxxxx>
> ---
> Changes in V2:
>  - 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
> 
> Changes in V3:
>  - No Change.
> 
> Changes in V4:
>  - As per Mark's comment move peak_bw guess as twice of avg_bw if
>    nothing mentioned explicitly to ICC core.
> 
> Changes in V5:
>  - Add icc_enable/disable to power on/off call.
>  - Save some non-zero avg/peak value to ICC core by calling geni_icc_set_bw
>    from probe so that when resume/icc_enable is called NOC are running at
>    some non-zero value.
> 
> Changes in V6:
>  - As per Matthias's comment made print statement consistent across driver
> 
> Changes in V7:
>  - As per Matthias's comment removed usage of peak_bw variable because we don't
>    have explicit peak requirement, we were voting peak = avg and this can be
>    tracked using single variable for avg bw.
>  - As per Matthias's comment improved print log.
> 
>  drivers/spi/spi-qcom-qspi.c | 57 ++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 56 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/spi-qcom-qspi.c b/drivers/spi/spi-qcom-qspi.c
> index 3c4f83b..092ac27 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 +140,9 @@ 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;

I should have noticed this earlier, but the field isn't needed now that
we have icc_enable/disable(). The bandwidth is set in
qcom_qspi_transfer_one() and that's it.

>From my side it would be fine to remove the field in a follow up patch,
to avoid respinning the series yet another time just for this.

Reviewed-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>