[PATCH v4 3/4] remoteproc: qcom: q6v5: Add common panic handler

[Bjorn Andersson <bjorn.andersson@linaro.org>]

Add a common panic handler that invokes a stop request and sleep enough
to let the remoteproc flush it's caches etc in order to aid post mortem
debugging. For now a hard coded 200ms is returned to the remoteproc
core, this value is taken from the downstream kernel.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---

Change since v3:
 - Change return type to unsigned long

 drivers/remoteproc/qcom_q6v5.c | 20 ++++++++++++++++++++
 drivers/remoteproc/qcom_q6v5.h |  1 +
 2 files changed, 21 insertions(+)

diff --git a/drivers/remoteproc/qcom_q6v5.c b/drivers/remoteproc/qcom_q6v5.c
index cb0f4a0be032..111a442c993c 100644
--- a/drivers/remoteproc/qcom_q6v5.c
+++ b/drivers/remoteproc/qcom_q6v5.c
@@ -15,6 +15,8 @@
 #include <linux/remoteproc.h>
 #include "qcom_q6v5.h"
 
+#define Q6V5_PANIC_DELAY_MS	200
+
 /**
  * qcom_q6v5_prepare() - reinitialize the qcom_q6v5 context before start
  * @q6v5:	reference to qcom_q6v5 context to be reinitialized
@@ -162,6 +164,24 @@ int qcom_q6v5_request_stop(struct qcom_q6v5 *q6v5)
 }
 EXPORT_SYMBOL_GPL(qcom_q6v5_request_stop);
 
+/**
+ * qcom_q6v5_panic() - panic handler to invoke a stop on the remote
+ * @q6v5:	reference to qcom_q6v5 context
+ *
+ * Set the stop bit and sleep in order to allow the remote processor to flush
+ * its caches etc for post mortem debugging.
+ *
+ * Return: 200ms
+ */
+unsigned long qcom_q6v5_panic(struct qcom_q6v5 *q6v5)
+{
+	qcom_smem_state_update_bits(q6v5->state,
+				    BIT(q6v5->stop_bit), BIT(q6v5->stop_bit));
+
+	return Q6V5_PANIC_DELAY_MS;
+}
+EXPORT_SYMBOL_GPL(qcom_q6v5_panic);
+
 /**
  * qcom_q6v5_init() - initializer of the q6v5 common struct
  * @q6v5:	handle to be initialized
diff --git a/drivers/remoteproc/qcom_q6v5.h b/drivers/remoteproc/qcom_q6v5.h
index 7ac92c1e0f49..c4ed887c1499 100644
--- a/drivers/remoteproc/qcom_q6v5.h
+++ b/drivers/remoteproc/qcom_q6v5.h
@@ -42,5 +42,6 @@ int qcom_q6v5_prepare(struct qcom_q6v5 *q6v5);
 int qcom_q6v5_unprepare(struct qcom_q6v5 *q6v5);
 int qcom_q6v5_request_stop(struct qcom_q6v5 *q6v5);
 int qcom_q6v5_wait_for_start(struct qcom_q6v5 *q6v5, int timeout);
+unsigned long qcom_q6v5_panic(struct qcom_q6v5 *q6v5);
 
 #endif
-- 
2.24.0