qti: Add SPMI PMIC arbitrator driver
This patch adds a very rudimentary driver for the SPMI arbitrator used
to access the PMIC. It doesn't support all the controller's actual
arbitration features, so it should probably not be used concurrently
with a running kernel (and it's also not optimized for performance). But
it can be used to set a few registers during boot or on shutdown to
control reset handling, which is all we need it for.
Change-Id: I8631c34a2a89ac71aa1ec9b8266e818c922fe34a
Signed-off-by: Julius Werner <jwerner@chromium.org>
diff --git a/plat/qti/common/inc/spmi_arb.h b/plat/qti/common/inc/spmi_arb.h
new file mode 100644
index 0000000..362f740
--- /dev/null
+++ b/plat/qti/common/inc/spmi_arb.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2020, Google LLC. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef SPMI_ARB_H
+#define SPMI_ARB_H
+
+#include <stdint.h>
+
+/*******************************************************************************
+ * WARNING: This driver does not arbitrate access with the kernel. These APIs
+ * must only be called when the kernel is known to be quiesced (such as before
+ * boot or while the system is shutting down).
+ ******************************************************************************/
+
+/* 32-bit addresses combine (U)SID, PID and register address. */
+
+int spmi_arb_read8(uint32_t addr);
+int spmi_arb_write8(uint32_t addr, uint8_t data);
+
+#endif /* SPMI_ARB_H */