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-rw-r--r--drivers/hwtracing/coresight/coresight-etm4x.c27
-rw-r--r--drivers/hwtracing/coresight/coresight-etm4x.h3
2 files changed, 20 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))
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
index 4a695bf90582..72c9a55e67df 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.h
+++ b/drivers/hwtracing/coresight/coresight-etm4x.h
@@ -407,6 +407,8 @@ struct etmv4_save_state {
* @config: structure holding configuration parameters.
* @save_state: State to be preserved across power loss
* @state_needs_restore: True when there is context to restore after PM exit
+ * @skip_power_up: Indicates if an implementation can skip powering up
+ * the trace unit.
*/
struct etmv4_drvdata {
void __iomem *base;
@@ -454,6 +456,7 @@ struct etmv4_drvdata {
struct etmv4_config config;
struct etmv4_save_state *save_state;
bool state_needs_restore;
+ bool skip_power_up;
};
/* Address comparator access types */