Commit ceac257d authored by Cristian Marussi's avatar Cristian Marussi Committed by Sudeep Holla
Browse files

firmware: arm_scmi: Add optional transport_init/exit support 

Some SCMI transport could need to perform some transport specific setup
before they can be used by the SCMI core transport layer: typically this
early setup consists in registering with some other kernel subsystem.

Add the optional capability for a transport to provide a couple of init
and exit functions that are assured to be called early during the SCMI
core initialization phase, well before the SCMI core probing step.

[ Peter: Adapted RFC patch by Cristian for submission to upstream. ]

Link: https://lore.kernel.org/r/20210803131024.40280-4-cristian.marussi@arm.com


Signed-off-by: default avatarPeter Hilber <peter.hilber@opensynergy.com>
[ Cristian: Fixed scmi_transports_exit point of invocation ]
Signed-off-by: default avatarCristian Marussi <cristian.marussi@arm.com>
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
parent 36690325

drivers/firmware/arm_scmi/common.h

+8 −0
Original line number Diff line number Diff line
@@ -321,6 +321,12 @@ struct scmi_device *scmi_child_dev_find(struct device *parent, 
/**

 * 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 that can be pending
@@ -328,6 +334,8 @@ struct scmi_device *scmi_child_dev_find(struct device *parent, 
 * @max_msg_size: Maximum size of data per message that can be handled.

 */

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;

drivers/firmware/arm_scmi/driver.c

+57 −0
Original line number Diff line number Diff line
@@ -1581,10 +1581,65 @@ static struct platform_driver scmi_driver = { 
	.remove = 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 int __init scmi_driver_init(void)

{

	int ret;



	scmi_bus_init();



	/* Initialize any compiled-in transport which provided an init/exit */

	ret = scmi_transports_init();

	if (ret)

		return ret;



	scmi_base_register();



	scmi_clock_register();
@@ -1613,6 +1668,8 @@ static void __exit scmi_driver_exit(void) 


	scmi_bus_exit();



	scmi_transports_exit();



	platform_driver_unregister(&scmi_driver);

}

module_exit(scmi_driver_exit);