Add support for devices with system instruction access only. They don't have a memory mapped interface and thus are not AMBA devices. System register access is not permitted to TRCPDCR and thus skip access to them.
Cc: Mike Leach mike.leach@linaro.org Reviewed-by: Mathieu Poirier mathieu.poirier@linaro.org Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com --- Changes since v5: - Rebased to accommodate check_arch_features(). Added comments to explain why we don't pass PID for system register based devices. Changes since v4 - Add "remove" callback for platform_driver. - Dropped Reviewed-by tag from Mathieu due to the above
Changes since v3 - Improve comment over "TRCPDCR" usage with sysreg - Rename etm_xx => etm4_xx - Update the compatible to "arm,coresight-etm4x-sysreg" --- .../coresight/coresight-etm4x-core.c | 68 +++++++++++++++++-- 1 file changed, 63 insertions(+), 5 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index 63a5e11b5f3f..3d3165dd09d4 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -27,6 +27,7 @@ #include <linux/seq_file.h> #include <linux/uaccess.h> #include <linux/perf_event.h> +#include <linux/platform_device.h> #include <linux/pm_runtime.h> #include <linux/property.h>
@@ -1736,9 +1737,6 @@ static int etm4_probe(struct device *dev, void __iomem *base, u32 etm_pid) return -ENOMEM; }
- if (fwnode_property_present(dev_fwnode(dev), "qcom,skip-power-up")) - drvdata->skip_power_up = true; - drvdata->base = base;
spin_lock_init(&drvdata->spinlock); @@ -1762,6 +1760,11 @@ static int etm4_probe(struct device *dev, void __iomem *base, u32 etm_pid) if (!drvdata->arch) return -EINVAL;
+ /* TRCPDCR is not accessible with system instructions. */ + if (!desc.access.io_mem || + fwnode_property_present(dev_fwnode(dev), "qcom,skip-power-up")) + drvdata->skip_power_up = true; + etm4_init_trace_id(drvdata); etm4_set_default(&drvdata->config);
@@ -1820,6 +1823,25 @@ static int etm4_probe_amba(struct amba_device *adev, const struct amba_id *id) return ret; }
+static int etm4_probe_platform_dev(struct platform_device *pdev) +{ + int ret; + + pm_runtime_get_noresume(&pdev->dev); + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + + /* + * System register based devices could match the + * HW by reading appropriate registers on the HW + * and thus we could skip the PID. + */ + ret = etm4_probe(&pdev->dev, NULL, 0); + + pm_runtime_put(&pdev->dev); + return ret; +} + static struct amba_cs_uci_id uci_id_etm4[] = { { /* ETMv4 UCI data */ @@ -1869,6 +1891,17 @@ static int __exit etm4_remove_amba(struct amba_device *adev) return 0; }
+static int __exit etm4_remove_platform_dev(struct platform_device *pdev) +{ + int ret = 0; + struct etmv4_drvdata *drvdata = dev_get_drvdata(&pdev->dev); + + if (drvdata) + ret = etm4_remove_dev(drvdata); + pm_runtime_disable(&pdev->dev); + return ret; +} + static const struct amba_id etm4_ids[] = { CS_AMBA_ID(0x000bb95d), /* Cortex-A53 */ CS_AMBA_ID(0x000bb95e), /* Cortex-A57 */ @@ -1901,6 +1934,21 @@ static struct amba_driver etm4x_amba_driver = { .id_table = etm4_ids, };
+static const struct of_device_id etm4_sysreg_match[] = { + { .compatible = "arm,coresight-etm4x-sysreg" }, + {} +}; + +static struct platform_driver etm4_platform_driver = { + .probe = etm4_probe_platform_dev, + .remove = etm4_remove_platform_dev, + .driver = { + .name = "coresight-etm4x", + .of_match_table = etm4_sysreg_match, + .suppress_bind_attrs = true, + }, +}; + static int __init etm4x_init(void) { int ret; @@ -1913,16 +1961,26 @@ static int __init etm4x_init(void)
ret = amba_driver_register(&etm4x_amba_driver); if (ret) { - pr_err("Error registering etm4x driver\n"); - etm4_pm_clear(); + pr_err("Error registering etm4x AMBA driver\n"); + goto clear_pm; }
+ ret = platform_driver_register(&etm4_platform_driver); + if (!ret) + return 0; + + pr_err("Error registering etm4x platform driver\n"); + amba_driver_unregister(&etm4x_amba_driver); + +clear_pm: + etm4_pm_clear(); return ret; }
static void __exit etm4x_exit(void) { amba_driver_unregister(&etm4x_amba_driver); + platform_driver_unregister(&etm4_platform_driver); etm4_pm_clear(); }