firmware: ti_sci: Add support for Device control

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 entitites within the SoC. Add support driver to allow
communication with system controller entity within the SoC using the
mailbox client.

We introduce the fundamental device management capability support to
the driver protocol as part of this change.

[d-gerlach@ti.com: Contributed device reset handling]
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>

1 files changed, 98 insertions, 0 deletions

diff --git a/drivers/firmware/ti_sci.h b/drivers/firmware/ti_sci.h
index e9dc53f26e0e..29ce0532a7ca 100644
--- a/drivers/firmware/ti_sci.h
+++ b/drivers/firmware/ti_sci.h
@@ -47,6 +47,11 @@
 #define TI_SCI_MSG_WAKE_REASON	0x0003
 #define TI_SCI_MSG_GOODBYE	0x0004
 
+/* Device requests */
+#define TI_SCI_MSG_SET_DEVICE_STATE	0x0200
+#define TI_SCI_MSG_GET_DEVICE_STATE	0x0201
+#define TI_SCI_MSG_SET_DEVICE_RESETS	0x0202
+
 /**
  * struct ti_sci_msg_hdr - Generic Message Header for All messages and responses
  * @type:	Type of messages: One of TI_SCI_MSG* values
@@ -90,4 +95,97 @@ struct ti_sci_msg_resp_version {
 	u8 abi_minor;
 } __packed;
 
+/**
+ * struct ti_sci_msg_req_set_device_state - Set the desired state of the device
+ * @hdr:		Generic header
+ * @id:	Indicates which device to modify
+ * @reserved: Reserved space in message, must be 0 for backward compatibility
+ * @state: The desired state of the device.
+ *
+ * Certain flags can also be set to alter the device state:
+ * + MSG_FLAG_DEVICE_WAKE_ENABLED - Configure the device to be a wake source.
+ * The meaning of this flag will vary slightly from device to device and from
+ * SoC to SoC but it generally allows the device to wake the SoC out of deep
+ * suspend states.
+ * + MSG_FLAG_DEVICE_RESET_ISO - Enable reset isolation for this device.
+ * + MSG_FLAG_DEVICE_EXCLUSIVE - Claim this device exclusively. When passed
+ * with STATE_RETENTION or STATE_ON, it will claim the device exclusively.
+ * If another host already has this device set to STATE_RETENTION or STATE_ON,
+ * the message will fail. Once successful, other hosts attempting to set
+ * STATE_RETENTION or STATE_ON will fail.
+ *
+ * Request type is TI_SCI_MSG_SET_DEVICE_STATE, responded with a generic
+ * ACK/NACK message.
+ */
+struct ti_sci_msg_req_set_device_state {
+	/* Additional hdr->flags options */
+#define MSG_FLAG_DEVICE_WAKE_ENABLED	TI_SCI_MSG_FLAG(8)
+#define MSG_FLAG_DEVICE_RESET_ISO	TI_SCI_MSG_FLAG(9)
+#define MSG_FLAG_DEVICE_EXCLUSIVE	TI_SCI_MSG_FLAG(10)
+	struct ti_sci_msg_hdr hdr;
+	u32 id;
+	u32 reserved;
+
+#define MSG_DEVICE_SW_STATE_AUTO_OFF	0
+#define MSG_DEVICE_SW_STATE_RETENTION	1
+#define MSG_DEVICE_SW_STATE_ON		2
+	u8 state;
+} __packed;
+
+/**
+ * struct ti_sci_msg_req_get_device_state - Request to get device.
+ * @hdr:		Generic header
+ * @id:		Device Identifier
+ *
+ * Request type is TI_SCI_MSG_GET_DEVICE_STATE, responded device state
+ * information
+ */
+struct ti_sci_msg_req_get_device_state {
+	struct ti_sci_msg_hdr hdr;
+	u32 id;
+} __packed;
+
+/**
+ * struct ti_sci_msg_resp_get_device_state - Response to get device request.
+ * @hdr:		Generic header
+ * @context_loss_count: Indicates how many times the device has lost context. A
+ *	driver can use this monotonic counter to determine if the device has
+ *	lost context since the last time this message was exchanged.
+ * @resets: Programmed state of the reset lines.
+ * @programmed_state:	The state as programmed by set_device.
+ *			- Uses the MSG_DEVICE_SW_* macros
+ * @current_state:	The actual state of the hardware.
+ *
+ * Response to request TI_SCI_MSG_GET_DEVICE_STATE.
+ */
+struct ti_sci_msg_resp_get_device_state {
+	struct ti_sci_msg_hdr hdr;
+	u32 context_loss_count;
+	u32 resets;
+	u8 programmed_state;
+#define MSG_DEVICE_HW_STATE_OFF		0
+#define MSG_DEVICE_HW_STATE_ON		1
+#define MSG_DEVICE_HW_STATE_TRANS	2
+	u8 current_state;
+} __packed;
+
+/**
+ * struct ti_sci_msg_req_set_device_resets - Set the desired resets
+ *				configuration of the device
+ * @hdr:		Generic header
+ * @id:	Indicates which device to modify
+ * @resets: A bit field of resets for the device. The meaning, behavior,
+ *	and usage of the reset flags are device specific. 0 for a bit
+ *	indicates releasing the reset represented by that bit while 1
+ *	indicates keeping it held.
+ *
+ * Request type is TI_SCI_MSG_SET_DEVICE_RESETS, responded with a generic
+ * ACK/NACK message.
+ */
+struct ti_sci_msg_req_set_device_resets {
+	struct ti_sci_msg_hdr hdr;
+	u32 id;
+	u32 resets;
+} __packed;
+
 #endif /* __TI_SCI_H */