remoteproc: add IPA notification to q6v5 driver

Set up a subdev in the q6v5 modem remoteproc driver that generates
event notifications for the IPA driver to use for initialization and
recovery following a modem shutdown or crash.

A pair of new functions provides a way for the IPA driver to register
and deregister a notification callback function that will be called
whenever modem events (about to boot, running, about to shut down,
etc.) occur.  A void pointer value (provided by the IPA driver at
registration time) and an event type are supplied to the callback
function.

One event, MODEM_REMOVING, is signaled whenever the q6v5 driver is
about to remove the notification subdevice.  It requires the IPA
driver de-register its callback.

This sub-device is only used by the modem subsystem (MSS) driver,
so the code that adds the new subdev and allows registration and
deregistration of the notifier is found in "qcom_q6v6_mss.c".

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 38 insertions, 0 deletions

diff --git a/drivers/remoteproc/qcom_q6v5_mss.c b/drivers/remoteproc/qcom_q6v5_mss.c
index a1cc9cbe038f..f9ccce76e44b 100644
--- a/drivers/remoteproc/qcom_q6v5_mss.c
+++ b/drivers/remoteproc/qcom_q6v5_mss.c
@@ -22,6 +22,7 @@
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 #include <linux/remoteproc.h>
+#include "linux/remoteproc/qcom_q6v5_ipa_notify.h"
 #include <linux/reset.h>
 #include <linux/soc/qcom/mdt_loader.h>
 #include <linux/iopoll.h>
@@ -201,6 +202,7 @@ struct q6v5 {
 	struct qcom_rproc_glink glink_subdev;
 	struct qcom_rproc_subdev smd_subdev;
 	struct qcom_rproc_ssr ssr_subdev;
+	struct qcom_rproc_ipa_notify ipa_notify_subdev;
 	struct qcom_sysmon *sysmon;
 	bool need_mem_protection;
 	bool has_alt_reset;
@@ -1540,6 +1542,39 @@ static int q6v5_alloc_memory_region(struct q6v5 *qproc)
 	return 0;
 }
 
+#if IS_ENABLED(CONFIG_QCOM_Q6V5_IPA_NOTIFY)
+
+/* Register IPA notification function */
+int qcom_register_ipa_notify(struct rproc *rproc, qcom_ipa_notify_t notify,
+			     void *data)
+{
+	struct qcom_rproc_ipa_notify *ipa_notify;
+	struct q6v5 *qproc = rproc->priv;
+
+	if (!notify)
+		return -EINVAL;
+
+	ipa_notify = &qproc->ipa_notify_subdev;
+	if (ipa_notify->notify)
+		return -EBUSY;
+
+	ipa_notify->notify = notify;
+	ipa_notify->data = data;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(qcom_register_ipa_notify);
+
+/* Deregister IPA notification function */
+void qcom_deregister_ipa_notify(struct rproc *rproc)
+{
+	struct q6v5 *qproc = rproc->priv;
+
+	qproc->ipa_notify_subdev.notify = NULL;
+}
+EXPORT_SYMBOL_GPL(qcom_deregister_ipa_notify);
+#endif /* !IS_ENABLED(CONFIG_QCOM_Q6V5_IPA_NOTIFY) */
+
 static int q6v5_probe(struct platform_device *pdev)
 {
 	const struct rproc_hexagon_res *desc;
@@ -1664,6 +1699,7 @@ static int q6v5_probe(struct platform_device *pdev)
 	qcom_add_glink_subdev(rproc, &qproc->glink_subdev);
 	qcom_add_smd_subdev(rproc, &qproc->smd_subdev);
 	qcom_add_ssr_subdev(rproc, &qproc->ssr_subdev, "mpss");
+	qcom_add_ipa_notify_subdev(rproc, &qproc->ipa_notify_subdev);
 	qproc->sysmon = qcom_add_sysmon_subdev(rproc, "modem", 0x12);
 	if (IS_ERR(qproc->sysmon)) {
 		ret = PTR_ERR(qproc->sysmon);
@@ -1677,6 +1713,7 @@ static int q6v5_probe(struct platform_device *pdev)
 	return 0;
 
 detach_proxy_pds:
+	qcom_remove_ipa_notify_subdev(qproc->rproc, &qproc->ipa_notify_subdev);
 	q6v5_pds_detach(qproc, qproc->proxy_pds, qproc->proxy_pd_count);
 detach_active_pds:
 	q6v5_pds_detach(qproc, qproc->active_pds, qproc->active_pd_count);
@@ -1693,6 +1730,7 @@ static int q6v5_remove(struct platform_device *pdev)
 	rproc_del(qproc->rproc);
 
 	qcom_remove_sysmon_subdev(qproc->sysmon);
+	qcom_remove_ipa_notify_subdev(qproc->rproc, &qproc->ipa_notify_subdev);
 	qcom_remove_glink_subdev(qproc->rproc, &qproc->glink_subdev);
 	qcom_remove_smd_subdev(qproc->rproc, &qproc->smd_subdev);
 	qcom_remove_ssr_subdev(qproc->rproc, &qproc->ssr_subdev);