diff options
| author | Tingwei Zhang <tingwei@codeaurora.org> | 2020-07-16 20:57:32 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-07-21 16:48:38 +0300 |
| commit | 02510a5aa78df45ff9a22def37e5c18677d4d659 (patch) | |
| tree | 21acdf5564448aedeedbde789f299ebce20fbdf2 /drivers/hwtracing/coresight/coresight-etm4x.c | |
| parent | 9cfb556357d56895ae50f0f3c691730d640530d2 (diff) | |
coresight: etm4x: Add support to skip trace unit power up
On some Qualcomm Technologies Inc. SoCs like SC7180, there
exists a hardware errata where the APSS (Application Processor
SubSystem)/CPU watchdog counter is stopped when the trace unit
power up ETM register is set (TRCPDCR.PU = 1). Since the ETMs
share the same power domain as that of respective CPU cores,
they are powered on when the CPU core is powered on. So we can
skip powering up of trace unit after checking for this errata
via new property called "qcom,skip-power-up".
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Co-developed-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200716175746.3338735-4-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwtracing/coresight/coresight-etm4x.c')
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-etm4x.c | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c index 0c35cd5e0d1d..2290f41f0074 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.c +++ b/drivers/hwtracing/coresight/coresight-etm4x.c @@ -196,12 +196,14 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata) writel_relaxed(config->vmid_mask0, drvdata->base + TRCVMIDCCTLR0); writel_relaxed(config->vmid_mask1, drvdata->base + TRCVMIDCCTLR1); - /* - * Request to keep the trace unit powered and also - * emulation of powerdown - */ - writel_relaxed(readl_relaxed(drvdata->base + TRCPDCR) | TRCPDCR_PU, - drvdata->base + TRCPDCR); + if (!drvdata->skip_power_up) { + /* + * Request to keep the trace unit powered and also + * emulation of powerdown + */ + writel_relaxed(readl_relaxed(drvdata->base + TRCPDCR) | + TRCPDCR_PU, drvdata->base + TRCPDCR); + } /* Enable the trace unit */ writel_relaxed(1, drvdata->base + TRCPRGCTLR); @@ -476,10 +478,12 @@ static void etm4_disable_hw(void *info) CS_UNLOCK(drvdata->base); - /* power can be removed from the trace unit now */ - control = readl_relaxed(drvdata->base + TRCPDCR); - control &= ~TRCPDCR_PU; - writel_relaxed(control, drvdata->base + TRCPDCR); + if (!drvdata->skip_power_up) { + /* power can be removed from the trace unit now */ + control = readl_relaxed(drvdata->base + TRCPDCR); + control &= ~TRCPDCR_PU; + writel_relaxed(control, drvdata->base + TRCPDCR); + } control = readl_relaxed(drvdata->base + TRCPRGCTLR); @@ -1468,6 +1472,9 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id) return -ENOMEM; } + if (fwnode_property_present(dev_fwnode(dev), "qcom,skip-power-up")) + drvdata->skip_power_up = true; + /* Validity for the resource is already checked by the AMBA core */ base = devm_ioremap_resource(dev, res); if (IS_ERR(base)) |