firmware: arm_scmi: Remove legacy transport-layer code

Since all SCMI transports have been made standalone drivers, remove all the
core SCMI stack legacy support that was needed to run transports as built
into the stack.

Signed-off-by: Cristian Marussi <[e-mail]>
Message-Id: <[e-mail]>
Signed-off-by: Sudeep Holla <[e-mail]>

drivers/firmware/arm_scmi/common.h

···
 /**
  * struct scmi_transport_ops - Structure representing a SCMI transport ops
  *
- * @link_supplier: Optional callback to add link to a supplier device
  * @chan_available: Callback to check if channel is available or not
  * @chan_setup: Callback to allocate and setup a channel
  * @chan_free: Callback to free a channel
···
  * @poll_done: Callback to poll transfer status
  */
 struct scmi_transport_ops {
-	int (*link_supplier)(struct device *dev);
 	bool (*chan_available)(struct device_node *of_node, int idx);
 	int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev,
 			  bool tx);
···
 /**
  * struct scmi_desc - Description of SoC integration
  *
- * @transport_init: An optional function that a transport can provide to
- *		    initialize some transport-specific setup during SCMI core
- *		    initialization, so ahead of SCMI core probing.
- * @transport_exit: An optional function that a transport can provide to
- *		    de-initialize some transport-specific setup during SCMI core
- *		    de-initialization, so after SCMI core removal.
  * @ops: Pointer to the transport specific ops structure
  * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds)
  * @max_msg: Maximum number of messages for a channel type (tx or rx) that can
···
  *		    when requested.
  */
 struct scmi_desc {
-	int (*transport_init)(void);
-	void (*transport_exit)(void);
 	const struct scmi_transport_ops *ops;
 	int max_rx_timeout_ms;
 	int max_msg;
···
 					    struct scmi_xfer *xfer,
 					    unsigned int timeout_ms);
 
-void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv);
-
 enum debug_counters {
 	SENT_OK,
 	SENT_FAIL,
···
 	MSG_NOMEM = -4,
 	MSG_MBOX_SPURIOUS = -5,
 };
-
-void scmi_bad_message_trace(struct scmi_chan_info *cinfo, u32 msg_hdr,
-			    enum scmi_bad_msg err);
 
 /* shmem related declarations */
 struct scmi_shared_mem;
···
 		   },							       \
 	.probe = __tag##_probe,						       \
 }
-
-extern const struct scmi_shared_mem_operations scmi_shmem_ops;
-extern const struct scmi_message_operations scmi_msg_ops;
 
 void scmi_notification_instance_data_set(const struct scmi_handle *handle,
 					 void *priv);

drivers/firmware/arm_scmi/driver.c

···
  * various power domain DVFS including the core/cluster, certain system
  * clocks configuration, thermal sensors and many others.
  *
- * Copyright (C) 2018-2021 ARM Ltd.
+ * Copyright (C) 2018-2024 ARM Ltd.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
···
 #define handle_to_scmi_info(h)	container_of(h, struct scmi_info, handle)
 #define bus_nb_to_scmi_info(nb)	container_of(nb, struct scmi_info, bus_nb)
 #define req_nb_to_scmi_info(nb)	container_of(nb, struct scmi_info, dev_req_nb)
+
+static void scmi_rx_callback(struct scmi_chan_info *cinfo,
+			     u32 msg_hdr, void *priv);
+static void scmi_bad_message_trace(struct scmi_chan_info *cinfo,
+				   u32 msg_hdr, enum scmi_bad_msg err);
 
 static struct scmi_transport_core_operations scmi_trans_core_ops = {
 	.bad_message_trace = scmi_bad_message_trace,
···
  * timed-out message that arrives and as such, can be traced only referring to
  * the header content, since the payload is missing/unreliable.
  */
-void scmi_bad_message_trace(struct scmi_chan_info *cinfo, u32 msg_hdr,
-			    enum scmi_bad_msg err)
+static void scmi_bad_message_trace(struct scmi_chan_info *cinfo, u32 msg_hdr,
+				   enum scmi_bad_msg err)
 {
 	char *tag;
 	struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
···
  * NOTE: This function will be invoked in IRQ context, hence should be
  * as optimal as possible.
  */
-void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv)
+static void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr,
+			     void *priv)
 {
 	u8 msg_type = MSG_XTRACT_TYPE(msg_hdr);
 
···
 	struct device *dev = &pdev->dev;
 	struct device_node *child, *np = dev->of_node;
 
-	desc = of_device_get_match_data(dev);
+	desc = scmi_transport_setup(dev);
 	if (!desc) {
-		desc = scmi_transport_setup(dev);
-		if (!desc) {
-			err_str = "transport invalid\n";
-			ret = -EINVAL;
-			goto out_err;
-		}
+		err_str = "transport invalid\n";
+		ret = -EINVAL;
+		goto out_err;
 	}
 
 	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
···
 			 "SCMI System wide atomic threshold set to %d us\n",
 			 info->atomic_threshold);
 	handle->is_transport_atomic = scmi_is_transport_atomic;
-
-	if (desc->ops->link_supplier) {
-		ret = desc->ops->link_supplier(dev);
-		if (ret) {
-			err_str = "transport not ready\n";
-			goto clear_ida;
-		}
-	}
 
 	/* Setup all channels described in the DT at first */
 	ret = scmi_channels_setup(info);
···
 };
 ATTRIBUTE_GROUPS(versions);
 
-/* Each compatible listed below must have descriptor associated with it */
-static const struct of_device_id scmi_of_match[] = {
-	{ /* Sentinel */ },
-};
-
-MODULE_DEVICE_TABLE(of, scmi_of_match);
-
 static struct platform_driver scmi_driver = {
 	.driver = {
 		   .name = "arm-scmi",
 		   .suppress_bind_attrs = true,
-		   .of_match_table = scmi_of_match,
 		   .dev_groups = versions_groups,
 		   },
 	.probe = scmi_probe,
 	.remove_new = scmi_remove,
 };
-
-/**
- * __scmi_transports_setup  - Common helper to call transport-specific
- * .init/.exit code if provided.
- *
- * @init: A flag to distinguish between init and exit.
- *
- * Note that, if provided, we invoke .init/.exit functions for all the
- * transports currently compiled in.
- *
- * Return: 0 on Success.
- */
-static inline int __scmi_transports_setup(bool init)
-{
-	int ret = 0;
-	const struct of_device_id *trans;
-
-	for (trans = scmi_of_match; trans->data; trans++) {
-		const struct scmi_desc *tdesc = trans->data;
-
-		if ((init && !tdesc->transport_init) ||
-		    (!init && !tdesc->transport_exit))
-			continue;
-
-		if (init)
-			ret = tdesc->transport_init();
-		else
-			tdesc->transport_exit();
-
-		if (ret) {
-			pr_err("SCMI transport %s FAILED initialization!\n",
-			       trans->compatible);
-			break;
-		}
-	}
-
-	return ret;
-}
-
-static int __init scmi_transports_init(void)
-{
-	return __scmi_transports_setup(true);
-}
-
-static void __exit scmi_transports_exit(void)
-{
-	__scmi_transports_setup(false);
-}
 
 static struct dentry *scmi_debugfs_init(void)
 {
···
 
 static int __init scmi_driver_init(void)
 {
-	int ret;
-
 	/* Bail out if no SCMI transport was configured */
 	if (WARN_ON(!IS_ENABLED(CONFIG_ARM_SCMI_HAVE_TRANSPORT)))
 		return -EINVAL;
-
-	/* Initialize any compiled-in transport which provided an init/exit */
-	ret = scmi_transports_init();
-	if (ret)
-		return ret;
 
 	if (IS_ENABLED(CONFIG_ARM_SCMI_HAVE_SHMEM))
 		scmi_trans_core_ops.shmem = scmi_shared_mem_operations_get();
···
 	scmi_system_unregister();
 	scmi_powercap_unregister();
 	scmi_pinctrl_unregister();
-
-	scmi_transports_exit();
 
 	platform_driver_unregister(&scmi_driver);
 

drivers/firmware/arm_scmi/msg.c

···
 	memcpy(xfer->rx.buf, msg->msg_payload, xfer->rx.len);
 }
 
-const struct scmi_message_operations scmi_msg_ops = {
+static const struct scmi_message_operations scmi_msg_ops = {
 	.tx_prepare = msg_tx_prepare,
 	.command_size = msg_command_size,
 	.response_size = msg_response_size,

drivers/firmware/arm_scmi/shmem.c

···
 	return addr;
 }
 
-const struct scmi_shared_mem_operations scmi_shmem_ops = {
+static const struct scmi_shared_mem_operations scmi_shmem_ops = {
 	.tx_prepare = shmem_tx_prepare,
 	.read_header = shmem_read_header,
 	.fetch_response = shmem_fetch_response,