[PATCH v4 04/37] [RFC] firmware: arm_scmi: introduce bare get/put protocols ops

From: Cristian Marussi
Date: Wed Jan 06 2021 - 15:17:47 EST


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

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

Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>
---
These non devres methods are probably not needed, given the devm_ ones are
already provided and any SCMI driver (user of the API) has surely available
an scmi_device reference to use in the devm_ flavour...so the RFC
---
drivers/firmware/arm_scmi/driver.c | 34 ++++++++++++++++++++++++++++++
include/linux/scmi_protocol.h | 8 +++++++
2 files changed, 42 insertions(+)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index fbc3ba1b69f6..e6e760501587 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -710,6 +710,38 @@ void scmi_release_protocol(struct scmi_handle *handle, u8 protocol_id)
mutex_unlock(&info->protocols_mtx);
}

+/**
+ * scmi_get_protocol_operations - Get protocol operations
+ * @handle: A reference to the SCMI platform instance.
+ * @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.
+ *
+ * Return: A reference to the requested protocol operations or error.
+ * Must be checked for errors by caller.
+ */
+static const void __must_check *
+scmi_get_protocol_operations(struct scmi_handle *handle, u8 protocol_id,
+ struct scmi_protocol_handle **ph)
+{
+ struct scmi_protocol_instance *pi;
+
+ if (!ph)
+ return ERR_PTR(-EINVAL);
+
+ pi = scmi_get_protocol_instance(handle, protocol_id);
+ if (IS_ERR(pi))
+ return pi;
+
+ *ph = &pi->ph;
+
+ return pi->proto->ops;
+}
+
void scmi_setup_protocol_implemented(const struct scmi_handle *handle,
u8 *prot_imp)
{
@@ -1078,6 +1110,8 @@ static int scmi_probe(struct platform_device *pdev)
handle->version = &info->version;
handle->devm_get_ops = scmi_devm_get_protocol_ops;
handle->devm_put_ops = scmi_devm_put_protocol_ops;
+ handle->get_ops = scmi_get_protocol_operations;
+ handle->put_ops = scmi_release_protocol;

ret = scmi_txrx_setup(info, dev, SCMI_PROTOCOL_BASE);
if (ret)
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index 2fd2fffb4024..8a2bb723602f 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -598,6 +598,9 @@ struct scmi_notify_ops {
* @devm_get_ops: devres managed method to acquire a protocol and get specific
* operations and a dedicated protocol handler
* @devm_put_ops: devres managed method to release a protocol
+ * @get_ops: method to acquire a protocol and get specific operations and a
+ * dedicated protocol handler
+ * @put_ops: 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)
@@ -629,6 +632,11 @@ struct scmi_handle {
struct scmi_protocol_handle **ph);
void (*devm_put_ops)(struct scmi_device *sdev, u8 proto);

+ const void __must_check *
+ (*get_ops)(struct scmi_handle *handle, u8 proto,
+ struct scmi_protocol_handle **ph);
+ void (*put_ops)(struct scmi_handle *handle, u8 proto);
+
const struct scmi_notify_ops *notify_ops;
/* for protocol internal use */
void *perf_priv;
--
2.17.1