rpmsg: Introduce "poll" to endpoint ops

This allows rpmsg backends to implement polling of the outgoing buffer,
which provides poll support to user space when using the rpmsg character
device.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
index 1cfb775e8e82b8b391108c700abba57f92867066..3bf1418683b1828e3313d98f22bd717ad5d859ee 100644 (file)
--- a/drivers/rpmsg/rpmsg_core.c
+++ b/drivers/rpmsg/rpmsg_core.c
@@ -239,6 +239,26 @@ int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
 }
 EXPORT_SYMBOL(rpmsg_trysendto);
 
+/**
+ * rpmsg_poll() - poll the endpoint's send buffers
+ * @ept:       the rpmsg endpoint
+ * @filp:      file for poll_wait()
+ * @wait:      poll_table for poll_wait()
+ *
+ * Returns mask representing the current state of the endpoint's send buffers
+ */
+unsigned int rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
+                       poll_table *wait)
+{
+       if (WARN_ON(!ept))
+               return 0;
+       if (!ept->ops->poll)
+               return 0;
+
+       return ept->ops->poll(ept, filp, wait);
+}
+EXPORT_SYMBOL(rpmsg_poll);
+
 /**
  * rpmsg_send_offchannel() - send a message using explicit src/dst addresses
  * @ept: the rpmsg endpoint

diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h
index 8075a20f919b21caabbd13235f9bb2632cc800f1..6176f2457b6b8b72b40682aa52a5d417f94ff283 100644 (file)
--- a/drivers/rpmsg/rpmsg_internal.h
+++ b/drivers/rpmsg/rpmsg_internal.h
@@ -21,6 +21,7 @@
 #define __RPMSG_INTERNAL_H__
 
 #include <linux/rpmsg.h>
+#include <linux/poll.h>
 
 #define to_rpmsg_device(d) container_of(d, struct rpmsg_device, dev)
 #define to_rpmsg_driver(d) container_of(d, struct rpmsg_driver, drv)
@@ -70,6 +71,8 @@ struct rpmsg_endpoint_ops {
        int (*trysendto)(struct rpmsg_endpoint *ept, void *data, int len, u32 dst);
        int (*trysend_offchannel)(struct rpmsg_endpoint *ept, u32 src, u32 dst,
                             void *data, int len);
+       unsigned int (*poll)(struct rpmsg_endpoint *ept, struct file *filp,
+                            poll_table *wait);
 };
 
 int rpmsg_register_device(struct rpmsg_device *rpdev);

diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h
index 18f9e1ae4b7e77a8189bcb72134473ce49d0df44..10d6ae8bbb7dfbb56f55f79434e0c900972878db 100644 (file)
--- a/include/linux/rpmsg.h
+++ b/include/linux/rpmsg.h
@@ -41,6 +41,7 @@
 #include <linux/mod_devicetable.h>
 #include <linux/kref.h>
 #include <linux/mutex.h>
+#include <linux/poll.h>
 
 #define RPMSG_ADDR_ANY         0xFFFFFFFF
 
@@ -156,6 +157,9 @@ int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst);
 int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
                             void *data, int len);
 
+unsigned int rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
+                       poll_table *wait);
+
 #else
 
 static inline int register_rpmsg_device(struct rpmsg_device *dev)
@@ -254,6 +258,15 @@ static inline int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src,
        return -ENXIO;
 }
 
+static inline unsigned int rpmsg_poll(struct rpmsg_endpoint *ept,
+                                     struct file *filp, poll_table *wait)
+{
+       /* This shouldn't be possible */
+       WARN_ON(1);
+
+       return 0;
+}
+
 #endif /* IS_ENABLED(CONFIG_RPMSG) */
 
 /* use a macro to avoid include chaining to get THIS_MODULE */