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, 91 insertions, 0 deletions

diff --git a/include/linux/soc/ti/ti_sci_protocol.h b/include/linux/soc/ti/ti_sci_protocol.h
index e73483fd5327..87fa73851471 100644
--- a/include/linux/soc/ti/ti_sci_protocol.h
+++ b/include/linux/soc/ti/ti_sci_protocol.h
@@ -33,12 +33,103 @@ struct ti_sci_version_info {
 	char firmware_description[32];
 };
 
+struct ti_sci_handle;
+
+/**
+ * struct ti_sci_dev_ops - Device control operations
+ * @get_device: Command to request for device managed by TISCI
+ *		Returns 0 for successful exclusive request, else returns
+ *		corresponding error message.
+ * @idle_device: Command to idle a device managed by TISCI
+ *		Returns 0 for successful exclusive request, else returns
+ *		corresponding error message.
+ * @put_device:	Command to release a device managed by TISCI
+ *		Returns 0 for successful release, else returns corresponding
+ *		error message.
+ * @is_valid:	Check if the device ID is a valid ID.
+ *		Returns 0 if the ID is valid, else returns corresponding error.
+ * @get_context_loss_count: Command to retrieve context loss counter - this
+ *		increments every time the device looses context. Overflow
+ *		is possible.
+ *		- count: pointer to u32 which will retrieve counter
+ *		Returns 0 for successful information request and count has
+ *		proper data, else returns corresponding error message.
+ * @is_idle:	Reports back about device idle state
+ *		- req_state: Returns requested idle state
+ *		Returns 0 for successful information request and req_state and
+ *		current_state has proper data, else returns corresponding error
+ *		message.
+ * @is_stop:	Reports back about device stop state
+ *		- req_state: Returns requested stop state
+ *		- current_state: Returns current stop state
+ *		Returns 0 for successful information request and req_state and
+ *		current_state has proper data, else returns corresponding error
+ *		message.
+ * @is_on:	Reports back about device ON(or active) state
+ *		- req_state: Returns requested ON state
+ *		- current_state: Returns current ON state
+ *		Returns 0 for successful information request and req_state and
+ *		current_state has proper data, else returns corresponding error
+ *		message.
+ * @is_transitioning: Reports back if the device is in the middle of transition
+ *		of state.
+ *		-current_state: Returns 'true' if currently transitioning.
+ * @set_device_resets: Command to configure resets for device managed by TISCI.
+ *		-reset_state: Device specific reset bit field
+ *		Returns 0 for successful request, else returns
+ *		corresponding error message.
+ * @get_device_resets: Command to read state of resets for device managed
+ *		by TISCI.
+ *		-reset_state: pointer to u32 which will retrieve resets
+ *		Returns 0 for successful request, else returns
+ *		corresponding error message.
+ *
+ * NOTE: for all these functions, the following parameters are generic in
+ * nature:
+ * -handle:	Pointer to TISCI handle as retrieved by *ti_sci_get_handle
+ * -id:		Device Identifier
+ *
+ * Request for the device - NOTE: the client MUST maintain integrity of
+ * usage count by balancing get_device with put_device. No refcounting is
+ * managed by driver for that purpose.
+ */
+struct ti_sci_dev_ops {
+	int (*get_device)(const struct ti_sci_handle *handle, u32 id);
+	int (*idle_device)(const struct ti_sci_handle *handle, u32 id);
+	int (*put_device)(const struct ti_sci_handle *handle, u32 id);
+	int (*is_valid)(const struct ti_sci_handle *handle, u32 id);
+	int (*get_context_loss_count)(const struct ti_sci_handle *handle,
+				      u32 id, u32 *count);
+	int (*is_idle)(const struct ti_sci_handle *handle, u32 id,
+		       bool *requested_state);
+	int (*is_stop)(const struct ti_sci_handle *handle, u32 id,
+		       bool *req_state, bool *current_state);
+	int (*is_on)(const struct ti_sci_handle *handle, u32 id,
+		     bool *req_state, bool *current_state);
+	int (*is_transitioning)(const struct ti_sci_handle *handle, u32 id,
+				bool *current_state);
+	int (*set_device_resets)(const struct ti_sci_handle *handle, u32 id,
+				 u32 reset_state);
+	int (*get_device_resets)(const struct ti_sci_handle *handle, u32 id,
+				 u32 *reset_state);
+};
+
+/**
+ * struct ti_sci_ops - Function support for TI SCI
+ * @dev_ops:	Device specific operations
+ */
+struct ti_sci_ops {
+	struct ti_sci_dev_ops dev_ops;
+};
+
 /**
  * struct ti_sci_handle - Handle returned to TI SCI clients for usage.
  * @version:	structure containing version information
+ * @ops:	operations that are made available to TI SCI clients
  */
 struct ti_sci_handle {
 	struct ti_sci_version_info version;
+	struct ti_sci_ops ops;
 };
 
 #if IS_ENABLED(CONFIG_TI_SCI_PROTOCOL)