[PATCH V5 07/11] coresight: catu: Move ACPI support from AMBA driver to platform driver
Suzuki K Poulose
suzuki.poulose at arm.com
Wed Mar 6 09:21:57 PST 2024
On 06/03/2024 06:14, Anshuman Khandual wrote:
>
>
> On 3/5/24 23:02, Suzuki K Poulose wrote:
>> On 22/02/2024 08:21, Anshuman Khandual wrote:
>>> Add support for the catu devices in a new 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. But first this renames and then refactors catu_probe()
>>> and catu_remove(), making sure it can be used both for platform and AMBA
>>> drivers. This also moves pm_runtime_put() from catu_probe() to the callers.
>>>
>>> Cc: Lorenzo Pieralisi <lpieralisi at kernel.org>
>>> Cc: Sudeep Holla <sudeep.holla at arm.com>
>>> Cc: Suzuki K Poulose <suzuki.poulose at arm.com>
>>> Cc: Mike Leach <mike.leach at linaro.org>
>>> Cc: James Clark <james.clark at arm.com>
>>> Cc: linux-acpi at vger.kernel.org
>>> Cc: linux-arm-kernel at lists.infradead.org
>>> Cc: linux-kernel at vger.kernel.org
>>> Cc: coresight at lists.linaro.org
>>> Acked-by: Sudeep Holla <sudeep.holla at arm.com> # For ACPI related changes
>>> Reviewed-by: James Clark <james.clark at arm.com>
>>> Signed-off-by: Anshuman Khandual <anshuman.khandual at arm.com>
>>> ---
>>> Changes in V5:
>>>
>>> - Updated commit message regarding catu_probe/remove() refactoring and renaming
>>>
>>> drivers/acpi/arm64/amba.c | 1 -
>>> drivers/hwtracing/coresight/coresight-catu.c | 142 ++++++++++++++++---
>>> drivers/hwtracing/coresight/coresight-catu.h | 1 +
>>> 3 files changed, 124 insertions(+), 20 deletions(-)
>>>
>>> diff --git a/drivers/acpi/arm64/amba.c b/drivers/acpi/arm64/amba.c
>>> index afb6afb66967..587061b0fd2f 100644
>>> --- a/drivers/acpi/arm64/amba.c
>>> +++ b/drivers/acpi/arm64/amba.c
>>> @@ -27,7 +27,6 @@ static const struct acpi_device_id amba_id_list[] = {
>>> {"ARMHC503", 0}, /* ARM CoreSight Debug */
>>> {"ARMHC979", 0}, /* ARM CoreSight TPIU */
>>> {"ARMHC97C", 0}, /* ARM CoreSight SoC-400 TMC, SoC-600 ETF/ETB */
>>> - {"ARMHC9CA", 0}, /* ARM CoreSight CATU */
>>> {"", 0},
>>> };
>>> diff --git a/drivers/hwtracing/coresight/coresight-catu.c b/drivers/hwtracing/coresight/coresight-catu.c
>>> index 3949ded0d4fa..a3ea46b53898 100644
>>> --- a/drivers/hwtracing/coresight/coresight-catu.c
>>> +++ b/drivers/hwtracing/coresight/coresight-catu.c
>>> @@ -7,6 +7,8 @@
>>> * Author: Suzuki K Poulose <suzuki.poulose at arm.com>
>>> */
>>> +#include <linux/platform_device.h>
>>> +#include <linux/acpi.h>
>>> #include <linux/amba/bus.h>
>>> #include <linux/device.h>
>>> #include <linux/dma-mapping.h>
>>> @@ -502,28 +504,20 @@ static const struct coresight_ops catu_ops = {
>>> .helper_ops = &catu_helper_ops,
>>> };
>>> -static int catu_probe(struct amba_device *adev, const struct amba_id *id)
>>> +static int __catu_probe(struct device *dev, struct resource *res)
>>> {
>>> int ret = 0;
>>> u32 dma_mask;
>>> - struct catu_drvdata *drvdata;
>>> + struct catu_drvdata *drvdata = dev_get_drvdata(dev);
>>> struct coresight_desc catu_desc;
>>> struct coresight_platform_data *pdata = NULL;
>>> - struct device *dev = &adev->dev;
>>> void __iomem *base;
>>> catu_desc.name = coresight_alloc_device_name(&catu_devs, dev);
>>> if (!catu_desc.name)
>>> return -ENOMEM;
>>> - drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
>>> - if (!drvdata) {
>>> - ret = -ENOMEM;
>>> - goto out;
>>> - }
>>> -
>>> - dev_set_drvdata(dev, drvdata);
>>> - base = devm_ioremap_resource(dev, &adev->res);
>>> + base = devm_ioremap_resource(dev, res);
>>> if (IS_ERR(base)) {
>>> ret = PTR_ERR(base);
>>> goto out;
>>> @@ -567,19 +561,39 @@ static int catu_probe(struct amba_device *adev, const struct amba_id *id)
>>> drvdata->csdev = coresight_register(&catu_desc);
>>> if (IS_ERR(drvdata->csdev))
>>> ret = PTR_ERR(drvdata->csdev);
>>> - else
>>> - pm_runtime_put(&adev->dev);
>>> out:
>>> return ret;
>>> }
>>> -static void catu_remove(struct amba_device *adev)
>>> +static int catu_probe(struct amba_device *adev, const struct amba_id *id)
>>> {
>>> - struct catu_drvdata *drvdata = dev_get_drvdata(&adev->dev);
>>> + struct catu_drvdata *drvdata;
>>> + int ret;
>>> +
>>> + drvdata = devm_kzalloc(&adev->dev, sizeof(*drvdata), GFP_KERNEL);
>>> + if (!drvdata)
>>> + return -ENOMEM;
>>> +
>>> + amba_set_drvdata(adev, drvdata);
>>> + ret = __catu_probe(&adev->dev, &adev->res);
>>> + if (!ret)
>>> + pm_runtime_put(&adev->dev);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static void __catu_remove(struct device *dev)
>>> +{
>>> + struct catu_drvdata *drvdata = dev_get_drvdata(dev);
>>> coresight_unregister(drvdata->csdev);
>>> }
>>> +static void catu_remove(struct amba_device *adev)
>>> +{
>>> + __catu_remove(&adev->dev);
>>> +}
>>> +
>>> static struct amba_id catu_ids[] = {
>>> CS_AMBA_ID(0x000bb9ee),
>>> {},
>>> @@ -598,13 +612,103 @@ static struct amba_driver catu_driver = {
>>> .id_table = catu_ids,
>>> };
>>> +static int catu_platform_probe(struct platform_device *pdev)
>>> +{
>>> + struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> + struct catu_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);
>>> + }
>>> + }
>>
>> ---<8---
>>
>> The above section seems unncessary as we already try to map the base in __catu_probe ?
>
> Agreed, though it seems unnecessary, there is a small difference in there. In the platform
> driver case i.e catu_platform_probe(), clk_put() is called on platform clock drvdata->pclk
> (just enabled earlier) for cases when devm_ioremap_resource() fails.
>
> To remove this redundancy, let's move devm_ioremap_resource() into it's AMBA caller i.e
> catu_probe() thus dropping struct resource argument from __catu_probe(). Similar situation
> is present in coresight-cpu-debug driver as well, will fix that.
>
> But there are some other drivers in the series where coresight_get_enable_apb_pclk() called
> on 'drvdata->pclk' and devm_ioremap_resource() is attempted inside the factored __xxx_probe()
> function which is common for both AMBA and platform drivers.
>
> Such drivers are ...
>
> - tpiu
> - tmc
> - stm
> - replicator
>
> IMHO it would be better to follow same scheme for all drivers in the series. Please do let
> me know which method will be preferred.
Lets pass the "res" to the common probe and deal it there.
>
>>
>>> +
>
>>> + pm_runtime_get_noresume(&pdev->dev);
>>> + pm_runtime_set_active(&pdev->dev);
>>> + pm_runtime_enable(&pdev->dev);
>>> +
>>> + dev_set_drvdata(&pdev->dev, drvdata);
>>> + ret = __catu_probe(&pdev->dev, res);
>>> + pm_runtime_put(&pdev->dev);
>>> + if (ret)
>>> + pm_runtime_disable(&pdev->dev);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static int catu_platform_remove(struct platform_device *pdev)
>>> +{
>>> + struct catu_drvdata *drvdata = dev_get_drvdata(&pdev->dev);
>>> +
>>> + if (drvdata)
>>> + __catu_remove(&pdev->dev);
>>
>> I don't understand the need for if () check here (and on all the other drivers). Even if we have a drvdata != NULL, what guarantees that
>> the drvdata->csdev is valid (which is used in xx_remove) ?
>
> Agreed, although drvdata is derived in __xxx_remove() functions, a pre-check here is not
> required - similar to the AMBA remove path. Sure, will drop them across drivers.
No, my point is : Is there a case where :
1) drvdata == NULL, but we have a device to do some cleanup ?
2) If drvdata != NULL, but drvdata->csdev is not valid, because we
failed to register the coresight device ?
Suzuki
>
>>
>> Suzuki
>>
>>> +
>>> + pm_runtime_disable(&pdev->dev);
>>> + if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
>>> + clk_put(drvdata->pclk);
>>> + return 0;
>>> +}
>>> +
>>> +#ifdef CONFIG_PM
>>> +static int catu_runtime_suspend(struct device *dev)
>>> +{
>>> + struct catu_drvdata *drvdata = dev_get_drvdata(dev);
>>> +
>>> + if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
>>> + clk_disable_unprepare(drvdata->pclk);
>>> + return 0;
>>> +}
>>> +
>>> +static int catu_runtime_resume(struct device *dev)
>>> +{
>>> + struct catu_drvdata *drvdata = dev_get_drvdata(dev);
>>> +
>>> + if (drvdata && !IS_ERR_OR_NULL(drvdata->pclk))
>>> + clk_prepare_enable(drvdata->pclk);
>>> + return 0;
>>> +}
>>> +#endif
>>> +
>>> +static const struct dev_pm_ops catu_dev_pm_ops = {
>>> + SET_RUNTIME_PM_OPS(catu_runtime_suspend, catu_runtime_resume, NULL)
>>> +};
>>> +
>>> +#ifdef CONFIG_ACPI
>>> +static const struct acpi_device_id catu_acpi_ids[] = {
>>> + {"ARMHC9CA", 0}, /* ARM CoreSight CATU */
>>> + {},
>>> +};
>>> +
>>> +MODULE_DEVICE_TABLE(acpi, catu_acpi_ids);
>>> +#endif
>>> +
>>> +static struct platform_driver catu_platform_driver = {
>>> + .probe = catu_platform_probe,
>>> + .remove = catu_platform_remove,
>>> + .driver = {
>>> + .name = "coresight-catu-platform",
>>> + .acpi_match_table = ACPI_PTR(catu_acpi_ids),
>>> + .suppress_bind_attrs = true,
>>> + .pm = &catu_dev_pm_ops,
>>> + },
>>> +};
>>> +
>>> static int __init catu_init(void)
>>> {
>>> int ret;
>>> - ret = amba_driver_register(&catu_driver);
>>> - if (ret)
>>> - pr_info("Error registering catu driver\n");
>>> + ret = coresight_init_driver("catu", &catu_driver, &catu_platform_driver);
>>> tmc_etr_set_catu_ops(&etr_catu_buf_ops);
>>> return ret;
>>> }
>>> @@ -612,7 +716,7 @@ static int __init catu_init(void)
>>> static void __exit catu_exit(void)
>>> {
>>> tmc_etr_remove_catu_ops();
>>> - amba_driver_unregister(&catu_driver);
>>> + coresight_remove_driver(&catu_driver, &catu_platform_driver);
>>> }
>>> module_init(catu_init);
>>> diff --git a/drivers/hwtracing/coresight/coresight-catu.h b/drivers/hwtracing/coresight/coresight-catu.h
>>> index 442e034bbfba..141feac1c14b 100644
>>> --- a/drivers/hwtracing/coresight/coresight-catu.h
>>> +++ b/drivers/hwtracing/coresight/coresight-catu.h
>>> @@ -61,6 +61,7 @@
>>> #define CATU_IRQEN_OFF 0x0
>>> struct catu_drvdata {
>>> + struct clk *pclk;
>>> void __iomem *base;
>>> struct coresight_device *csdev;
>>> int irq;
>>
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