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

[Akash Asthana <akashast@codeaurora.org>]

Hi Mark,

Would you be able to review/ack this QSPI patch, you have already acked 
"QUP SPI" patch from the series "[Patch V7 RESEND 4/7]"

Putting a gentle reminder in-case this patch is missed.

Regards,

Akash

On 6/9/2020 11:26 AM, 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>
> Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
> ---
> 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.
>
> Changes in Resend V7:
>   - As per Matthias comment removed "unsigned int avg_bw_cpu" from
>     struct qcom_qspi as we are using that variable only once.
>
>   drivers/spi/spi-qcom-qspi.c | 56 ++++++++++++++++++++++++++++++++++++++++++++-
>   1 file changed, 55 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/spi/spi-qcom-qspi.c b/drivers/spi/spi-qcom-qspi.c
> index 3c4f83b..b5b4cf6 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 +140,8 @@ 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;
> +	/* Lock to protect data accessed by IRQs */
>   	spinlock_t lock;
>   };
>   
> @@ -229,6 +231,7 @@ static int qcom_qspi_transfer_one(struct spi_master *master,
>   	int ret;
>   	unsigned long speed_hz;
>   	unsigned long flags;
> +	unsigned int avg_bw_cpu;
>   
>   	speed_hz = slv->max_speed_hz;
>   	if (xfer->speed_hz)
> @@ -241,6 +244,18 @@ static int qcom_qspi_transfer_one(struct spi_master *master,
>   		return ret;
>   	}
>   
> +	/*
> +	 * Set BW quota for CPU as driver supports FIFO mode only.
> +	 * We don't have explicit peak requirement so keep it equal to avg_bw.
> +	 */
> +	avg_bw_cpu = Bps_to_icc(speed_hz);
> +	ret = icc_set_bw(ctrl->icc_path_cpu_to_qspi, avg_bw_cpu, avg_bw_cpu);
> +	if (ret) {
> +		dev_err(ctrl->dev, "%s: ICC BW voting failed for cpu: %d\n",
> +			__func__, ret);
> +		return ret;
> +	}
> +
>   	spin_lock_irqsave(&ctrl->lock, flags);
>   
>   	/* We are half duplex, so either rx or tx will be set */
> @@ -458,6 +473,29 @@ static int qcom_qspi_probe(struct platform_device *pdev)
>   	if (ret)
>   		goto exit_probe_master_put;
>   
> +	ctrl->icc_path_cpu_to_qspi = devm_of_icc_get(dev, "qspi-config");
> +	if (IS_ERR(ctrl->icc_path_cpu_to_qspi)) {
> +		ret = PTR_ERR(ctrl->icc_path_cpu_to_qspi);
> +		if (ret != -EPROBE_DEFER)
> +			dev_err(dev, "Failed to get cpu path: %d\n", ret);
> +		goto exit_probe_master_put;
> +	}
> +	/* Set BW vote for register access */
> +	ret = icc_set_bw(ctrl->icc_path_cpu_to_qspi, Bps_to_icc(1000),
> +				Bps_to_icc(1000));
> +	if (ret) {
> +		dev_err(ctrl->dev, "%s: ICC BW voting failed for cpu: %d\n",
> +				__func__, ret);
> +		goto exit_probe_master_put;
> +	}
> +
> +	ret = icc_disable(ctrl->icc_path_cpu_to_qspi);
> +	if (ret) {
> +		dev_err(ctrl->dev, "%s: ICC disable failed for cpu: %d\n",
> +				__func__, ret);
> +		goto exit_probe_master_put;
> +	}
> +
>   	ret = platform_get_irq(pdev, 0);
>   	if (ret < 0)
>   		goto exit_probe_master_put;
> @@ -511,9 +549,17 @@ static int __maybe_unused qcom_qspi_runtime_suspend(struct device *dev)
>   {
>   	struct spi_master *master = dev_get_drvdata(dev);
>   	struct qcom_qspi *ctrl = spi_master_get_devdata(master);
> +	int ret;
>   
>   	clk_bulk_disable_unprepare(QSPI_NUM_CLKS, ctrl->clks);
>   
> +	ret = icc_disable(ctrl->icc_path_cpu_to_qspi);
> +	if (ret) {
> +		dev_err_ratelimited(ctrl->dev, "%s: ICC disable failed for cpu: %d\n",
> +			__func__, ret);
> +		return ret;
> +	}
> +
>   	return 0;
>   }
>   
> @@ -521,6 +567,14 @@ static int __maybe_unused qcom_qspi_runtime_resume(struct device *dev)
>   {
>   	struct spi_master *master = dev_get_drvdata(dev);
>   	struct qcom_qspi *ctrl = spi_master_get_devdata(master);
> +	int ret;
> +
> +	ret = icc_enable(ctrl->icc_path_cpu_to_qspi);
> +	if (ret) {
> +		dev_err_ratelimited(ctrl->dev, "%s: ICC enable failed for cpu: %d\n",
> +			__func__, ret);
> +		return ret;
> +	}
>   
>   	return clk_bulk_prepare_enable(QSPI_NUM_CLKS, ctrl->clks);
>   }

-- 
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