soc: qcom: ipa: AP/modem communications

This patch implements two forms of out-of-band communication between
the AP and modem.

  - QMI is a mechanism that allows clients running on the AP
    interact with services running on the modem (and vice-versa).
    The AP IPA driver uses QMI to communicate with the corresponding
    IPA driver resident on the modem, to agree on parameters used
    with the IPA hardware and to ensure both sides are ready before
    entering operational mode.

  - SMP2P is a more primitive mechanism available for the modem and
    AP to communicate with each other.  It provides a means for either
    the AP or modem to interrupt the other, and furthermore, to provide
    32 bits worth of information.  The IPA driver uses SMP2P to tell
    the modem what the state of the IPA clock was in the event of a
    crash.  This allows the modem to safely access the IPA hardware
    (or avoid doing so) when a crash occurs, for example, to access
    information within the IPA hardware.

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

1 files changed, 48 insertions, 0 deletions

diff --git a/drivers/net/ipa/ipa_smp2p.h b/drivers/net/ipa/ipa_smp2p.h
new file mode 100644
index 000000000000..1f65cdc9d406
--- /dev/null
+++ b/drivers/net/ipa/ipa_smp2p.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2019-2020 Linaro Ltd.
+ */
+#ifndef _IPA_SMP2P_H_
+#define _IPA_SMP2P_H_
+
+#include <linux/types.h>
+
+struct ipa;
+
+/**
+ * ipa_smp2p_init() - Initialize the IPA SMP2P subsystem
+ * @ipa:	IPA pointer
+ * @modem_init:	Whether the modem is responsible for GSI initialization
+ *
+ * @Return:	0 if successful, or a negative error code
+ *
+ */
+int ipa_smp2p_init(struct ipa *ipa, bool modem_init);
+
+/**
+ * ipa_smp2p_exit() - Inverse of ipa_smp2p_init()
+ * @ipa:	IPA pointer
+ */
+void ipa_smp2p_exit(struct ipa *ipa);
+
+/**
+ * ipa_smp2p_disable() - Prevent "ipa-setup-ready" interrupt handling
+ * @IPA:	IPA pointer
+ *
+ * Prevent handling of the "setup ready" interrupt from the modem.
+ * This is used before initiating shutdown of the driver.
+ */
+void ipa_smp2p_disable(struct ipa *ipa);
+
+/**
+ * ipa_smp2p_notify_reset() - Reset modem notification state
+ * @ipa:	IPA pointer
+ *
+ * If the modem crashes it queries the IPA clock state.  In cleaning
+ * up after such a crash this is used to reset some state maintained
+ * for managing this notification.
+ */
+void ipa_smp2p_notify_reset(struct ipa *ipa);
+
+#endif /* _IPA_SMP2P_H_ */