Re: [PATCH V3 5/8] spi: spi-geni-qcom: Add interconnect support

From: Matthias Kaehlcke <mka@chromium.org>
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,
	georgi.djakov@linaro.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
Subject: Re: [PATCH V3 5/8] spi: spi-geni-qcom: Add interconnect support
Date: Tue, 31 Mar 2020 12:02:49 -0700	[thread overview]
Message-ID: <20200331190249.GJ199755@google.com> (raw)
In-Reply-To: <1585652976-17481-6-git-send-email-akashast@codeaurora.org>

On Tue, Mar 31, 2020 at 04:39:33PM +0530, Akash Asthana wrote:
> Get the interconnect paths for SPI based Serial Engine device
> and vote according to the current bus speed of the driver.
> 
> Signed-off-by: Akash Asthana <akashast@codeaurora.org>
> ---
> Changes in V2:
>  - As per Bjorn's comment, removed se == NULL check from geni_spi_icc_get
>  - As per Bjorn's comment, removed code to set se->icc_path* to NULL in failure
>  - 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:
>  - As per Matthias's comment, use helper ICC function from geni-se driver.
> 
>  drivers/spi/spi-geni-qcom.c | 31 ++++++++++++++++++++++++++++++-
>  1 file changed, 30 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
> index c397242..f1dae2d 100644
> --- a/drivers/spi/spi-geni-qcom.c
> +++ b/drivers/spi/spi-geni-qcom.c
> @@ -234,6 +234,16 @@ static int setup_fifo_params(struct spi_device *spi_slv,
>  		return ret;
>  	}
>  
> +	/*
> +	 * Set BW quota for CPU as driver supports FIFO mode only.
> +	 * Assume peak bw as twice of avg bw.
> +	 */
> +	se->from_cpu.avg_bw = Bps_to_icc(mas->cur_speed_hz);
> +	se->from_cpu.peak_bw = Bps_to_icc(2 * mas->cur_speed_hz);
> +	ret = geni_icc_vote_on(se);
> +	if (ret)
> +		return ret;
> +
>  	clk_sel = idx & CLK_SEL_MSK;
>  	m_clk_cfg = (div << CLK_DIV_SHFT) | SER_CLK_EN;
>  	spi_setup_word_len(mas, spi_slv->mode, spi_slv->bits_per_word);
> @@ -578,6 +588,15 @@ static int spi_geni_probe(struct platform_device *pdev)
>  	spin_lock_init(&mas->lock);
>  	pm_runtime_enable(dev);
>  
> +	ret = geni_icc_get(&mas->se, "qup-core", "qup-config", NULL);
> +	if (ret)
> +		goto spi_geni_probe_runtime_disable;

This fails without providing any hints why, besides the error code.
It might be worth to add error logging to geni_icc_get().

> +	/* Set the bus quota to a reasonable value for register access */
> +	mas->se.to_core.avg_bw = Bps_to_icc(CORE_2X_50_MHZ);
> +	mas->se.to_core.peak_bw = Bps_to_icc(CORE_2X_100_MHZ);
> +	mas->se.from_cpu.avg_bw = GENI_DEFAULT_BW;
> +	mas->se.from_cpu.peak_bw = GENI_DEFAULT_BW;
> +
>  	ret = spi_geni_init(mas);
>  	if (ret)
>  		goto spi_geni_probe_runtime_disable;
> @@ -616,14 +635,24 @@ static int __maybe_unused spi_geni_runtime_suspend(struct device *dev)
>  {
>  	struct spi_master *spi = dev_get_drvdata(dev);
>  	struct spi_geni_master *mas = spi_master_get_devdata(spi);
> +	int ret;
> +
> +	ret = geni_se_resources_off(&mas->se);
> +	if (ret)
> +		return ret;
>  
> -	return geni_se_resources_off(&mas->se);
> +	return geni_icc_vote_off(&mas->se);
>  }
>  
>  static int __maybe_unused spi_geni_runtime_resume(struct device *dev)
>  {
>  	struct spi_master *spi = dev_get_drvdata(dev);
>  	struct spi_geni_master *mas = spi_master_get_devdata(spi);
> +	int ret;
> +
> +	ret = geni_icc_vote_on(&mas->se);
> +	if (ret)
> +		return ret;
>  
>  	return geni_se_resources_on(&mas->se);
>  }

Reviewed-by: Matthias Kaehlcke <mka@chromium.org>