Re: [PATCH 17/19] coresight: etm4x: Refactor probing routine

From: Mike Leach <mike.leach@linaro.org>
To: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Coresight ML <coresight@lists.linaro.org>,
	Anshuman.Khandual@arm.com,
	Mathieu Poirier <mathieu.poirier@linaro.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	Leo Yan <leo.yan@linaro.org>
Subject: Re: [PATCH 17/19] coresight: etm4x: Refactor probing routine
Date: Fri, 18 Sep 2020 16:35:48 +0100	[thread overview]
Message-ID: <CAJ9a7VgJUi10-0BLdz4KE35p7FaidkehOPbEZneAbej7vtOUoA@mail.gmail.com> (raw)
In-Reply-To: <20200911084119.1080694-18-suzuki.poulose@arm.com>

Reviewed-by: Mike Leach <mike.leach@linaro.org>


On Fri, 11 Sep 2020 at 09:41, Suzuki K Poulose <suzuki.poulose@arm.com> wrote:
>
> CoreSight ETM with system register access may not have a
> memory mapped i/o access. Refactor the ETM specific probing
> into a common routine to allow reusing the code for such ETMs.
>
> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
> Cc: Mike Leach <mike.leach@linaro.org>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> ---
>  drivers/hwtracing/coresight/coresight-etm4x.c | 38 ++++++++++++-------
>  1 file changed, 24 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c
> index dc5ac171db35..7d5f942c2108 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x.c
> @@ -1596,14 +1596,11 @@ static void __init etm4_pm_clear(void)
>         }
>  }
>
> -static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
> +static int etm4_probe(struct device *dev, void __iomem *base)
>  {
>         int ret;
> -       void __iomem *base;
> -       struct device *dev = &adev->dev;
>         struct coresight_platform_data *pdata = NULL;
>         struct etmv4_drvdata *drvdata;
> -       struct resource *res = &adev->res;
>         struct coresight_desc desc = { 0 };
>         struct etm_init_arg init_arg = { 0 };
>
> @@ -1627,11 +1624,6 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
>         if (fwnode_property_present(dev_fwnode(dev), "qcom,skip-power-up"))
>                 drvdata->skip_power_up = true;
>
> -       /* Validity for the resource is already checked by the AMBA core */
> -       base = devm_ioremap_resource(dev, res);
> -       if (IS_ERR(base))
> -               return PTR_ERR(base);
> -
>         drvdata->base = base;
>
>         spin_lock_init(&drvdata->spinlock);
> @@ -1665,7 +1657,7 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
>                 ret = PTR_ERR(pdata);
>                 goto err_arch_supported;
>         }
> -       adev->dev.platform_data = pdata;
> +       dev->platform_data = pdata;
>
>         desc.type = CORESIGHT_DEV_TYPE_SOURCE;
>         desc.subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_PROC;
> @@ -1685,7 +1677,6 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
>                 goto err_arch_supported;
>         }
>
> -       pm_runtime_put(&adev->dev);
>         dev_info(&drvdata->csdev->dev, "CPU%d: ETM v%d.%d initialized\n",
>                  drvdata->cpu, etm_devarch_arch(drvdata->arch),
>                  etm_devarch_rev(drvdata->arch));
> @@ -1702,6 +1693,25 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
>         return ret;
>  }
>
> +static int etm4_probe_amba(struct amba_device *adev, const struct amba_id *id)
> +{
> +       void __iomem *base;
> +       struct device *dev = &adev->dev;
> +       struct resource *res = &adev->res;
> +       int ret;
> +
> +       /* Validity for the resource is already checked by the AMBA core */
> +       base = devm_ioremap_resource(dev, res);
> +       if (IS_ERR(base))
> +               return PTR_ERR(base);
> +
> +       ret = etm4_probe(dev, base);
> +       if (!ret)
> +               pm_runtime_put(&adev->dev);
> +
> +       return ret;
> +}
> +
>  static struct amba_cs_uci_id uci_id_etm4[] = {
>         {
>                 /*  ETMv4 UCI data */
> @@ -1730,12 +1740,12 @@ static const struct amba_id etm4_ids[] = {
>         {},
>  };
>
> -static struct amba_driver etm4x_driver = {
> +static struct amba_driver etm4x_amba_driver = {
>         .drv = {
>                 .name   = "coresight-etm4x",
>                 .suppress_bind_attrs = true,
>         },
> -       .probe          = etm4_probe,
> +       .probe          = etm4_probe_amba,
>         .id_table       = etm4_ids,
>  };
>
> @@ -1749,7 +1759,7 @@ static int __init etm4x_init(void)
>         if (ret)
>                 return ret;
>
> -       ret = amba_driver_register(&etm4x_driver);
> +       ret = amba_driver_register(&etm4x_amba_driver);
>         if (ret) {
>                 pr_err("Error registering etm4x driver\n");
>                 etm4_pm_clear();
> --
> 2.24.1
>


--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK

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