Re: [PATCH 5/7] coresight: tmc: Move ACPI support from AMBA driver to platform driver

Sudeep Holla
2023-11-22T17:04:14Z

On Fri, Oct 27, 2023 at 12:59:41PM +0530, Anshuman Khandual wrote:
> Add support for the tmc devices in the platform driver, which can then be
> used on ACPI based platforms. This change would now allow runtime power
> management for ACPI based systems. The driver would try to enable the APB
> clock if available.
>
> Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
> Cc: Sudeep Holla <sudeep.holla@arm.com>
> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
> Cc: Mike Leach <mike.leach@linaro.org>
> Cc: James Clark <james.clark@arm.com>
> Cc: linux-acpi@vger.kernel.org
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org
> Cc: coresight@lists.linaro.org
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
> drivers/acpi/arm64/amba.c | 2 -
> .../hwtracing/coresight/coresight-tmc-core.c | 127 +++++++++++++++---
> drivers/hwtracing/coresight/coresight-tmc.h | 1 +
> 3 files changed, 113 insertions(+), 17 deletions(-)

[...]

> diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
> index 7ec5365e2b64..618bc0b7a1a5 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-core.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c

[...]

> @@ -573,9 +579,9 @@ static void tmc_shutdown(struct amba_device *adev)
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
> }
>
> -static void tmc_remove(struct amba_device *adev)
> +static void __tmc_remove(struct device *dev)
> {
> - struct tmc_drvdata *drvdata = dev_get_drvdata(&adev->dev);
> + struct tmc_drvdata *drvdata = dev_get_drvdata(dev);
>
> /*
> * Since misc_open() holds a refcount on the f_ops, which is
> @@ -586,6 +592,11 @@ static void tmc_remove(struct amba_device *adev)
> coresight_unregister(drvdata->csdev);
> }
>
> +static void tmc_remove(struct amba_device *adev)
> +{
> + __tmc_remove(&adev->dev);
> +}
> +
> static const struct amba_id tmc_ids[] = {
> CS_AMBA_ID(0x000bb961),
> /* Coresight SoC 600 TMC-ETR/ETS */
> @@ -613,6 +624,92 @@ static struct amba_driver tmc_driver = {
>
> module_amba_driver(tmc_driver);
>
> +static int tmc_platform_probe(struct platform_device *pdev)
> +{
> + struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + struct tmc_drvdata *drvdata;
> + int ret = 0;
> +
> + drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
> + if (!drvdata)
> + return -ENOMEM;
> +
> + drvdata->pclk = coresight_get_enable_apb_pclk(&pdev->dev);
> + if (IS_ERR(drvdata->pclk))
> + return -ENODEV;
> +

--->8
> + if (res) {
> + drvdata->base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(drvdata->base)) {
> + clk_put(drvdata->pclk);
> + return PTR_ERR(drvdata->base);
> + }
> + }
> +
---

You need drop the above hunk as _tmc_probe() already takes care of that.
This is the root cause for the issue I reported in the other thread. Also
sorry for the confusion, I had to refer to coresight-tmc-core.c and post
the patch to unify module_init/exit but completely mixed up the file/patch
and referred coresight-tpiu-core.c instead as that patch was dealing with
it.

--
Regards,
Sudeep