Re: [PATCH V2 3/7] coresight: catu: Move ACPI support from AMBA driver to platform driver

Suzuki K Poulose
2023-12-01T13:41:16Z

Hi Anshuman,

On 01/12/2023 06:20, 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.

This doesn't talk about the new helper. As such I would prefer that to
be a separate preparatory patch. See below.

>
> 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 | 1 -
> drivers/hwtracing/coresight/coresight-catu.c | 130 ++++++++++++++++---
> drivers/hwtracing/coresight/coresight-catu.h | 1 +
> drivers/hwtracing/coresight/coresight-core.c | 29 +++++
> include/linux/coresight.h | 7 +
> 5 files changed, 149 insertions(+), 19 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..ba5ee7d158dd 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@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;
> @@ -568,18 +562,35 @@ static int catu_probe(struct amba_device *adev, const struct amba_id *id)
> if (IS_ERR(drvdata->csdev))
> ret = PTR_ERR(drvdata->csdev);
> else
> - pm_runtime_put(&adev->dev);
> + pm_runtime_put(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;
> +
> + drvdata = devm_kzalloc(&adev->dev, sizeof(*drvdata), GFP_KERNEL);
> + if (!drvdata)
> + return -ENOMEM;
> +
> + amba_set_drvdata(adev, drvdata);
> + return __catu_probe(&adev->dev, &adev->res);
> +}
> +
> +static void __catu_remove(struct device *dev)
> {
> - struct catu_drvdata *drvdata = dev_get_drvdata(&adev->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 +609,96 @@ 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;
> +
> + if (res) {
> + drvdata->base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(drvdata->base)) {
> + clk_put(drvdata->pclk);
> + return PTR_ERR(drvdata->base);
> + }
> + }
> +
> + 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);
> + if (ret) {
> + pm_runtime_put_noidle(&pdev->dev);
> + pm_runtime_disable(&pdev->dev);
> + }
> + return ret;
> +}
> +
> +static int catu_platform_remove(struct platform_device *pdev)
> +{
> + __catu_remove(&pdev->dev);
> + return 0;
> +}
> +
> +#ifdef CONFIG_PM
> +static int catu_runtime_suspend(struct device *dev)
> +{
> + struct catu_drvdata *drvdata = dev_get_drvdata(dev);
> +
> + if (drvdata->pclk && !IS_ERR_OR_NULL(drvdata->pclk))

Only the second part is needed. IS_ERR_OR_NULL() already checks for NULL.

> + 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->pclk && !IS_ERR_OR_NULL(drvdata->pclk))

Same here.

> + 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 +706,7 @@ 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;
> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
> index 9fabe00a40d6..ede9b0723f95 100644
> --- a/drivers/hwtracing/coresight/coresight-core.c
> +++ b/drivers/hwtracing/coresight/coresight-core.c
> @@ -1833,6 +1833,35 @@ static void __exit coresight_exit(void)
> module_init(coresight_init);
> module_exit(coresight_exit);
>

---8>---

> +int coresight_init_driver(const char *drv, struct amba_driver *amba_drv,
> + struct platform_driver *pdev_drv)
> +{
> + int ret;
> +
> + ret = amba_driver_register(amba_drv);
> + if (ret) {
> + pr_err("%s: error registering AMBA driver\n", drv);
> + return ret;
> + }
> +
> + ret = platform_driver_register(pdev_drv);
> + if (!ret)
> + return 0;
> +
> + pr_err("%s: error registering platform driver\n", drv);
> + amba_driver_unregister(amba_drv);
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(coresight_init_driver);
> +
> +void coresight_remove_driver(struct amba_driver *amba_drv,
> + struct platform_driver *pdev_drv)
> +{
> + amba_driver_unregister(amba_drv);
> + platform_driver_unregister(pdev_drv);
> +}
> +EXPORT_SYMBOL_GPL(coresight_remove_driver);

Please could we split this into a separate patch itself ? Also, can we
not use them for the other components ? funnel, replicator ?

> +
> MODULE_LICENSE("GPL v2");
> MODULE_AUTHOR("Pratik Patel <pratikp@codeaurora.org>");
> MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
> diff --git a/include/linux/coresight.h b/include/linux/coresight.h
> index a269fffaf991..be7fe3793763 100644
> --- a/include/linux/coresight.h
> +++ b/include/linux/coresight.h
> @@ -12,6 +12,8 @@
> #include <linux/io.h>
> #include <linux/perf_event.h>
> #include <linux/sched.h>
> +#include <linux/amba/bus.h>
> +#include <linux/platform_device.h>
>
> /* Peripheral id registers (0xFD0-0xFEC) */
> #define CORESIGHT_PERIPHIDR4 0xfd0
> @@ -597,6 +599,11 @@ void coresight_relaxed_write64(struct coresight_device *csdev,
> u64 val, u32 offset);
> void coresight_write64(struct coresight_device *csdev, u64 val, u32 offset);
>
> +int coresight_init_driver(const char *drv, struct amba_driver *amba_drv,
> + struct platform_driver *pdev_drv);
> +
> +void coresight_remove_driver(struct amba_driver *amba_drv,
> + struct platform_driver *pdev_drv);
> #else
> static inline struct coresight_device *
> coresight_register(struct coresight_desc *desc) { return NULL; }

Suzuki