diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c index 5039df757127..32b550c91d9f 100644 --- a/drivers/rpmsg/rpmsg_core.c +++ b/drivers/rpmsg/rpmsg_core.c @@ -330,6 +330,25 @@ int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, } EXPORT_SYMBOL(rpmsg_trysend_offchannel); +/** + * rpmsg_set_flow_control() - request remote to pause/resume transmission + * @ept: the rpmsg endpoint + * @pause: pause transmission + * @dst: destination address of the endpoint + * + * Return: 0 on success and an appropriate error value on failure. + */ +int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool pause, u32 dst) +{ + if (WARN_ON(!ept)) + return -EINVAL; + if (!ept->ops->set_flow_control) + return -EOPNOTSUPP; + + return ept->ops->set_flow_control(ept, pause, dst); +} +EXPORT_SYMBOL_GPL(rpmsg_set_flow_control); + /** * rpmsg_get_mtu() - get maximum transmission buffer size for sending message. * @ept: the rpmsg endpoint @@ -539,6 +558,8 @@ static int rpmsg_dev_probe(struct device *dev) rpdev->ept = ept; rpdev->src = ept->addr; + + ept->flow_cb = rpdrv->flowcontrol; } err = rpdrv->probe(rpdev); diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h index 39b646d0d40d..b950d6f790a3 100644 --- a/drivers/rpmsg/rpmsg_internal.h +++ b/drivers/rpmsg/rpmsg_internal.h @@ -55,6 +55,7 @@ struct rpmsg_device_ops { * @trysendto: see @rpmsg_trysendto(), optional * @trysend_offchannel: see @rpmsg_trysend_offchannel(), optional * @poll: see @rpmsg_poll(), optional + * @set_flow_control: see @rpmsg_set_flow_control(), optional * @get_mtu: see @rpmsg_get_mtu(), optional * * Indirection table for the operations that a rpmsg backend should implement. @@ -75,6 +76,7 @@ struct rpmsg_endpoint_ops { void *data, int len); __poll_t (*poll)(struct rpmsg_endpoint *ept, struct file *filp, poll_table *wait); + int (*set_flow_control)(struct rpmsg_endpoint *ept, bool pause, u32 dst); ssize_t (*get_mtu)(struct rpmsg_endpoint *ept); }; diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h index 523c98b96cb4..90d8e4475f80 100644 --- a/include/linux/rpmsg.h +++ b/include/linux/rpmsg.h @@ -64,12 +64,14 @@ struct rpmsg_device { }; typedef int (*rpmsg_rx_cb_t)(struct rpmsg_device *, void *, int, void *, u32); +typedef int (*rpmsg_flowcontrol_cb_t)(struct rpmsg_device *, void *, bool); /** * struct rpmsg_endpoint - binds a local rpmsg address to its user * @rpdev: rpmsg channel device * @refcount: when this drops to zero, the ept is deallocated * @cb: rx callback handler + * @flow_cb: remote flow control callback handler * @cb_lock: must be taken before accessing/changing @cb * @addr: local rpmsg address * @priv: private data for the driver's use @@ -92,6 +94,7 @@ struct rpmsg_endpoint { struct rpmsg_device *rpdev; struct kref refcount; rpmsg_rx_cb_t cb; + rpmsg_flowcontrol_cb_t flow_cb; struct mutex cb_lock; u32 addr; void *priv; @@ -106,6 +109,7 @@ struct rpmsg_endpoint { * @probe: invoked when a matching rpmsg channel (i.e. device) is found * @remove: invoked when the rpmsg channel is removed * @callback: invoked when an inbound message is received on the channel + * @flowcontrol: invoked when remote side flow control request is received */ struct rpmsg_driver { struct device_driver drv; @@ -113,6 +117,7 @@ struct rpmsg_driver { int (*probe)(struct rpmsg_device *dev); void (*remove)(struct rpmsg_device *dev); int (*callback)(struct rpmsg_device *, void *, int, void *, u32); + int (*flowcontrol)(struct rpmsg_device *, void *, bool); }; static inline u16 rpmsg16_to_cpu(struct rpmsg_device *rpdev, __rpmsg16 val) @@ -192,6 +197,8 @@ __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp, ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept); +int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool pause, u32 dst); + #else static inline int rpmsg_register_device_override(struct rpmsg_device *rpdev, @@ -316,6 +323,14 @@ static inline ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept) return -ENXIO; } +static inline int rpmsg_set_flow_control(struct rpmsg_endpoint *ept, bool pause, u32 dst) +{ + /* This shouldn't be possible */ + WARN_ON(1); + + return -ENXIO; +} + #endif /* IS_ENABLED(CONFIG_RPMSG) */ /* use a macro to avoid include chaining to get THIS_MODULE */