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, 82 insertions, 0 deletions

diff --git a/include/linux/remoteproc/qcom_q6v5_ipa_notify.h b/include/linux/remoteproc/qcom_q6v5_ipa_notify.h
new file mode 100644
index 000000000000..0820edc0ab7d
--- /dev/null
+++ b/include/linux/remoteproc/qcom_q6v5_ipa_notify.h
@@ -0,0 +1,82 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/* Copyright (C) 2019 Linaro Ltd. */
+
+#ifndef __QCOM_Q6V5_IPA_NOTIFY_H__
+#define __QCOM_Q6V5_IPA_NOTIFY_H__
+
+#if IS_ENABLED(CONFIG_QCOM_Q6V5_IPA_NOTIFY)
+
+#include <linux/remoteproc.h>
+
+enum qcom_rproc_event {
+	MODEM_STARTING	= 0,	/* Modem is about to be started */
+	MODEM_RUNNING	= 1,	/* Startup complete; modem is operational */
+	MODEM_STOPPING	= 2,	/* Modem is about to shut down */
+	MODEM_CRASHED	= 3,	/* Modem has crashed (implies stopping) */
+	MODEM_OFFLINE	= 4,	/* Modem is now offline */
+	MODEM_REMOVING	= 5,	/* Modem is about to be removed */
+};
+
+typedef void (*qcom_ipa_notify_t)(void *data, enum qcom_rproc_event event);
+
+struct qcom_rproc_ipa_notify {
+	struct rproc_subdev subdev;
+
+	qcom_ipa_notify_t notify;
+	void *data;
+};
+
+/**
+ * qcom_add_ipa_notify_subdev() - Register IPA notification subdevice
+ * @rproc:	rproc handle
+ * @ipa_notify:	IPA notification subdevice handle
+ *
+ * Register the @ipa_notify subdevice with the @rproc so modem events
+ * can be sent to IPA when they occur.
+ *
+ * This is defined in "qcom_q6v5_ipa_notify.c".
+ */
+void qcom_add_ipa_notify_subdev(struct rproc *rproc,
+		struct qcom_rproc_ipa_notify *ipa_notify);
+
+/**
+ * qcom_remove_ipa_notify_subdev() - Remove IPA SSR subdevice
+ * @rproc:	rproc handle
+ * @ipa_notify:	IPA notification subdevice handle
+ *
+ * This is defined in "qcom_q6v5_ipa_notify.c".
+ */
+void qcom_remove_ipa_notify_subdev(struct rproc *rproc,
+		struct qcom_rproc_ipa_notify *ipa_notify);
+
+/**
+ * qcom_register_ipa_notify() - Register IPA notification function
+ * @rproc:	Remote processor handle
+ * @notify:	Non-null IPA notification callback function pointer
+ * @data:	Data supplied to IPA notification callback function
+ *
+ * @Return: 0 if successful, or a negative error code otherwise
+ *
+ * This is defined in "qcom_q6v5_mss.c".
+ */
+int qcom_register_ipa_notify(struct rproc *rproc, qcom_ipa_notify_t notify,
+			     void *data);
+/**
+ * qcom_deregister_ipa_notify() - Deregister IPA notification function
+ * @rproc:	Remote processor handle
+ *
+ * This is defined in "qcom_q6v5_mss.c".
+ */
+void qcom_deregister_ipa_notify(struct rproc *rproc);
+
+#else /* !IS_ENABLED(CONFIG_QCOM_Q6V5_IPA_NOTIFY) */
+
+struct qcom_rproc_ipa_notify { /* empty */ };
+
+#define qcom_add_ipa_notify_subdev(rproc, ipa_notify)		/* no-op */
+#define qcom_remove_ipa_notify_subdev(rproc, ipa_notify)	/* no-op */
+
+#endif /* !IS_ENABLED(CONFIG_QCOM_Q6V5_IPA_NOTIFY) */
+
+#endif /* !__QCOM_Q6V5_IPA_NOTIFY_H__ */