From 23934efe3748f6d9d8ac0760178a5ef1ed8320f4 Mon Sep 17 00:00:00 2001 From: Cristian Marussi Date: Tue, 16 Mar 2021 12:48:28 +0000 Subject: 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: Florian Fainelli Signed-off-by: Cristian Marussi Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/driver.c | 92 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 92 insertions(+) (limited to 'drivers/firmware') diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index b6f1a2866248..5a960a7fd973 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -15,6 +15,7 @@ */ #include +#include #include #include #include @@ -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) -- cgit 1.4.1