Commit 23934efe authored by Cristian Marussi's avatar Cristian Marussi Committed by Sudeep Holla
Browse files

firmware: arm_scmi: Introduce devres get/put protocols operations 

Expose to the SCMI drivers a new devres managed common protocols API
based on generic get/put methods and protocol handles.

All drivers still keep using the old API, no functional change.

Link: https://lore.kernel.org/r/20210316124903.35011-4-cristian.marussi@arm.com


Tested-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarCristian Marussi <cristian.marussi@arm.com>
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
parent d7b6cc56

drivers/firmware/arm_scmi/driver.c

+92 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
 */



#include <linux/bitmap.h>

#include <linux/device.h>

#include <linux/export.h>

#include <linux/idr.h>

#include <linux/io.h>
@@ -755,6 +756,95 @@ scmi_is_protocol_implemented(const struct scmi_handle *handle, u8 prot_id) 
	return false;

}



struct scmi_protocol_devres {

	struct scmi_handle *handle;

	u8 protocol_id;

};



static void scmi_devm_release_protocol(struct device *dev, void *res)

{

	struct scmi_protocol_devres *dres = res;



	scmi_protocol_release(dres->handle, dres->protocol_id);

}



/**

 * scmi_devm_protocol_get  - Devres managed get protocol operations and handle

 * @sdev: A reference to an scmi_device whose embedded struct device is to

 *	  be used for devres accounting.

 * @protocol_id: The protocol being requested.

 * @ph: A pointer reference used to pass back the associated protocol handle.

 *

 * Get hold of a protocol accounting for its usage, eventually triggering its

 * initialization, and returning the protocol specific operations and related

 * protocol handle which will be used as first argument in most of the

 * protocols operations methods.

 * Being a devres based managed method, protocol hold will be automatically

 * released, and possibly de-initialized on last user, once the SCMI driver

 * owning the scmi_device is unbound from it.

 *

 * Return: A reference to the requested protocol operations or error.

 *	   Must be checked for errors by caller.

 */

static const void __must_check *

scmi_devm_protocol_get(struct scmi_device *sdev, u8 protocol_id,

		       struct scmi_protocol_handle **ph)

{

	struct scmi_protocol_instance *pi;

	struct scmi_protocol_devres *dres;

	struct scmi_handle *handle = sdev->handle;



	if (!ph)

		return ERR_PTR(-EINVAL);



	dres = devres_alloc(scmi_devm_release_protocol,

			    sizeof(*dres), GFP_KERNEL);

	if (!dres)

		return ERR_PTR(-ENOMEM);



	pi = scmi_get_protocol_instance(handle, protocol_id);

	if (IS_ERR(pi)) {

		devres_free(dres);

		return pi;

	}



	dres->handle = handle;

	dres->protocol_id = protocol_id;

	devres_add(&sdev->dev, dres);



	*ph = &pi->ph;



	return pi->proto->ops;

}



static int scmi_devm_protocol_match(struct device *dev, void *res, void *data)

{

	struct scmi_protocol_devres *dres = res;



	if (WARN_ON(!dres || !data))

		return 0;



	return dres->protocol_id == *((u8 *)data);

}



/**

 * scmi_devm_protocol_put  - Devres managed put protocol operations and handle

 * @sdev: A reference to an scmi_device whose embedded struct device is to

 *	  be used for devres accounting.

 * @protocol_id: The protocol being requested.

 *

 * Explicitly release a protocol hold previously obtained calling the above

 * @scmi_devm_protocol_get.

 */

static void scmi_devm_protocol_put(struct scmi_device *sdev, u8 protocol_id)

{

	int ret;



	ret = devres_release(&sdev->dev, scmi_devm_release_protocol,

			     scmi_devm_protocol_match, &protocol_id);

	WARN_ON(ret);

}



/**

 * scmi_handle_get() - Get the SCMI handle for a device

 *
@@ -1009,6 +1099,8 @@ static int scmi_probe(struct platform_device *pdev) 
	handle = &info->handle;

	handle->dev = info->dev;

	handle->version = &info->version;

	handle->devm_protocol_get = scmi_devm_protocol_get;

	handle->devm_protocol_put = scmi_devm_protocol_put;



	ret = scmi_txrx_setup(info, dev, SCMI_PROTOCOL_BASE);

	if (ret)

include/linux/scmi_protocol.h

+11 −0
Original line number Diff line number Diff line
@@ -57,6 +57,8 @@ struct scmi_clock_info { 
};



struct scmi_handle;

struct scmi_device;

struct scmi_protocol_handle;



/**

 * struct scmi_clk_ops - represents the various operations provided
@@ -593,6 +595,9 @@ struct scmi_notify_ops { 
 * @sensor_ops: pointer to set of sensor protocol operations

 * @reset_ops: pointer to set of reset protocol operations

 * @voltage_ops: pointer to set of voltage protocol operations

 * @devm_protocol_get: devres managed method to acquire a protocol and get specific

 *		       operations and a dedicated protocol handler

 * @devm_protocol_put: devres managed method to release a protocol

 * @notify_ops: pointer to set of notifications related operations

 * @perf_priv: pointer to private data structure specific to performance

 *	protocol(for internal use only)
@@ -618,6 +623,12 @@ struct scmi_handle { 
	const struct scmi_sensor_ops *sensor_ops;

	const struct scmi_reset_ops *reset_ops;

	const struct scmi_voltage_ops *voltage_ops;



	const void __must_check *

		(*devm_protocol_get)(struct scmi_device *sdev, u8 proto,

				     struct scmi_protocol_handle **ph);

	void (*devm_protocol_put)(struct scmi_device *sdev, u8 proto);



	const struct scmi_notify_ops *notify_ops;

	/* for protocol internal use */

	void *perf_priv;