[PATCH v6 05/17] firmware: arm_scmi: Add transport optional init/exit support
From: Cristian Marussi <cristian.marussi@arm.com>
Date: 2021-07-12 14:19:18
Also in:
linux-arm-kernel
Subsystem:
system control & power/management interface (scpi/scmi) message protocol drivers, the rest · Maintainers:
Sudeep Holla, Linus Torvalds
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. ] Signed-off-by: Peter Hilber <redacted> [ Cristian: Fixed scmi_transports_exit point of invocation ] Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> --- v4 --> V5 - removed useless pr_debug - moved scmi_transport_exit() invocation --- drivers/firmware/arm_scmi/common.h | 8 +++++ drivers/firmware/arm_scmi/driver.c | 56 ++++++++++++++++++++++++++++++ 2 files changed, 64 insertions(+)
diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 7c2b9fd7e929..6bb734e0e3ac 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h@@ -321,6 +321,12 @@ struct scmi_device *scmi_child_dev_find(struct device *parent, /** * struct scmi_desc - Description of SoC integration * + * @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. + * @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 (*init)(void); + void (*exit)(void); const struct scmi_transport_ops *ops; int max_rx_timeout_ms; int max_msg;
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index d2c183fa7949..4c77ee13b1ad 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c@@ -1578,10 +1578,64 @@ 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->init) || (!init && !tdesc->exit)) + continue; + + if (init) + ret = tdesc->init(); + else + tdesc->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();
@@ -1610,6 +1664,8 @@ static void __exit scmi_driver_exit(void) scmi_bus_exit(); + scmi_transports_exit(); + platform_driver_unregister(&scmi_driver); } module_exit(scmi_driver_exit);
--
2.17.1