firmware: Add basic support for TI System Control Interface (TI-SCI) protocol

Texas Instrument's System Control Interface (TI-SCI) Message Protocol
is used in Texas Instrument's System on Chip (SoC) such as those
in keystone family K2G SoC to communicate between various compute
processors with a central system controller entity.

TI-SCI message protocol provides support for management of various
hardware entities within the SoC. Add support driver to allow
communication with system controller entity within the SoC using the
mailbox client.

We introduce the basic registration and query capability for the
driver protocol as part of this change. Subsequent patches add in
functionality specific to the TI-SCI features.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>

1 files changed, 69 insertions, 0 deletions

diff --git a/include/linux/soc/ti/ti_sci_protocol.h b/include/linux/soc/ti/ti_sci_protocol.h
new file mode 100644
index 000000000000..e73483fd5327
--- /dev/null
+++ b/include/linux/soc/ti/ti_sci_protocol.h
@@ -0,0 +1,69 @@
+/*
+ * Texas Instruments System Control Interface Protocol
+ *
+ * Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/
+ *	Nishanth Menon
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __TISCI_PROTOCOL_H
+#define __TISCI_PROTOCOL_H
+
+/**
+ * struct ti_sci_version_info - version information structure
+ * @abi_major:	Major ABI version. Change here implies risk of backward
+ *		compatibility break.
+ * @abi_minor:	Minor ABI version. Change here implies new feature addition,
+ *		or compatible change in ABI.
+ * @firmware_revision:	Firmware revision (not usually used).
+ * @firmware_description: Firmware description (not usually used).
+ */
+struct ti_sci_version_info {
+	u8 abi_major;
+	u8 abi_minor;
+	u16 firmware_revision;
+	char firmware_description[32];
+};
+
+/**
+ * struct ti_sci_handle - Handle returned to TI SCI clients for usage.
+ * @version:	structure containing version information
+ */
+struct ti_sci_handle {
+	struct ti_sci_version_info version;
+};
+
+#if IS_ENABLED(CONFIG_TI_SCI_PROTOCOL)
+const struct ti_sci_handle *ti_sci_get_handle(struct device *dev);
+int ti_sci_put_handle(const struct ti_sci_handle *handle);
+const struct ti_sci_handle *devm_ti_sci_get_handle(struct device *dev);
+
+#else	/* CONFIG_TI_SCI_PROTOCOL */
+
+static inline const struct ti_sci_handle *ti_sci_get_handle(struct device *dev)
+{
+	return ERR_PTR(-EINVAL);
+}
+
+static inline int ti_sci_put_handle(const struct ti_sci_handle *handle)
+{
+	return -EINVAL;
+}
+
+static inline
+const struct ti_sci_handle *devm_ti_sci_get_handle(struct device *dev)
+{
+	return ERR_PTR(-EINVAL);
+}
+
+#endif	/* CONFIG_TI_SCI_PROTOCOL */
+
+#endif	/* __TISCI_PROTOCOL_H */