On 12/8/23 11:09, Anshuman Khandual wrote:
> Add support for the dynamic replicator device in the platform driver, which
> can then be used on ACPI based platforms. This change would now allow
> runtime power management for repliacator devices on ACPI based systems.
>
> The driver would try to enable the APB clock if available. Also, rename the
> code to reflect the fact that it now handles both static and dynamic
> replicators.
>
> Cc: Lorenzo Pieralisi <lpieralisi@xxxxxxxxxx>
> Cc: Sudeep Holla <sudeep.holla@xxxxxxx>
> Cc: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> Cc: Mike Leach <mike.leach@xxxxxxxxxx>
> Cc: James Clark <james.clark@xxxxxxx>
> Cc: linux-acpi@xxxxxxxxxxxxxxx
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: coresight@xxxxxxxxxxxxxxxx
> Tested-by: Sudeep Holla <sudeep.holla@xxxxxxx> # Boot and driver probe only
> Acked-by: Sudeep Holla <sudeep.holla@xxxxxxx> # For ACPI related changes
> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
> ---
> Changes in V3:
>
> - Added commnets for 'drvdata->pclk'
> - Used coresight_init_driver()/coresight_remove_driver() helpers instead
> - Dropped pm_runtime_put() from replicator_probe()
> - Added pm_runtime_put() on success path in dynamic_replicator_probe()
> - Added pm_runtime_put() on success/error paths in
> replicator_platform_probe()
>
> drivers/acpi/arm64/amba.c | 1 -
> .../coresight/coresight-replicator.c | 81 ++++++++++---------
> 2 files changed, 42 insertions(+), 40 deletions(-)
>
> diff --git a/drivers/acpi/arm64/amba.c b/drivers/acpi/arm64/amba.c
> index 171b5c2c7edd..270f4e3819a2 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 */
> - {"ARMHC98D", 0}, /* ARM CoreSight Dynamic Replicator */
> {"ARMHC9CA", 0}, /* ARM CoreSight CATU */
> {"ARMHC9FF", 0}, /* ARM CoreSight Dynamic Funnel */
> {"", 0},
> diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c
> index b6be73034996..125b256cb8db 100644
> --- a/drivers/hwtracing/coresight/coresight-replicator.c
> +++ b/drivers/hwtracing/coresight/coresight-replicator.c
> @@ -31,6 +31,7 @@ DEFINE_CORESIGHT_DEVLIST(replicator_devs, "replicator");
> * @base: memory mapped base address for this component. Also indicates
> * whether this one is programmable or not.
> * @atclk: optional clock for the core parts of the replicator.
> + * @pclk: APB clock if present, otherwise NULL
> * @csdev: component vitals needed by the framework
> * @spinlock: serialize enable/disable operations.
> * @check_idfilter_val: check if the context is lost upon clock removal.
> @@ -38,6 +39,7 @@ DEFINE_CORESIGHT_DEVLIST(replicator_devs, "replicator");
> struct replicator_drvdata {
> void __iomem *base;
> struct clk *atclk;
> + struct clk *pclk;
> struct coresight_device *csdev;
> spinlock_t spinlock;
> bool check_idfilter_val;
> @@ -243,6 +245,10 @@ static int replicator_probe(struct device *dev, struct resource *res)
> return ret;
> }
>
> + drvdata->pclk = coresight_get_enable_apb_pclk(dev);
> + if (IS_ERR(drvdata->pclk))
> + return -ENODEV;
> +
> /*
> * Map the device base for dynamic-replicator, which has been
> * validated by AMBA core
> @@ -285,7 +291,6 @@ static int replicator_probe(struct device *dev, struct resource *res)
> }
>
> replicator_reset(drvdata);
> - pm_runtime_put(dev);
>
> out_disable_clk:
> if (ret && !IS_ERR_OR_NULL(drvdata->atclk))
> @@ -301,29 +306,31 @@ static int replicator_remove(struct device *dev)
> return 0;
> }
>
> -static int static_replicator_probe(struct platform_device *pdev)
> +static int replicator_platform_probe(struct platform_device *pdev)
> {
> + struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> int ret;
>
> pm_runtime_get_noresume(&pdev->dev);
> pm_runtime_set_active(&pdev->dev);
> pm_runtime_enable(&pdev->dev);
>
> - /* Static replicators do not have programming base */
> - ret = replicator_probe(&pdev->dev, NULL);
> -
> - if (ret) {
> - pm_runtime_put_noidle(&pdev->dev);
> - pm_runtime_disable(&pdev->dev);
> - }
> + ret = replicator_probe(&pdev->dev, res);
> + pm_runtime_put(&pdev->dev);
I believe pm_runtime_disable() would still be needed on the error path. Otherwise
pm_runtime_enable() will remain unbalanced on this error path when the replicator
module could not be loaded.
--- a/drivers/hwtracing/coresight/coresight-replicator.c
+++ b/drivers/hwtracing/coresight/coresight-replicator.c
@@ -317,6 +317,8 @@ static int replicator_platform_probe(struct platform_device *pdev)
ret = replicator_probe(&pdev->dev, res);
pm_runtime_put(&pdev->dev);
+ if (ret)
+ pm_runtime_disable(&pdev->dev);
return ret;
}
Similar constructs in this error path are also required in all other drivers (except
cpu debug) as well.
