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[v3,2/4] rpmsg: qcom_smd: Implement endpoint "poll"

Message ID 20170111143513.32251-2-bjorn.andersson@linaro.org (mailing list archive)
State Accepted
Headers show

Commit Message

Bjorn Andersson Jan. 11, 2017, 2:35 p.m. UTC 
Add support for polling the status of the write buffer so that user
space can use rpmsg character devices in non-blocking mode.

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

Changes since v2:
- None

Changes since v1:
- New patch

 drivers/rpmsg/qcom_smd.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
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Patch

diff --git a/drivers/rpmsg/qcom_smd.c b/drivers/rpmsg/qcom_smd.c
index 3dd73edaa525..9e2af6a18aa2 100644
--- a/drivers/rpmsg/qcom_smd.c
+++ b/drivers/rpmsg/qcom_smd.c
@@ -919,6 +919,21 @@  static int qcom_smd_trysend(struct rpmsg_endpoint *ept, void *data, int len)
 	return __qcom_smd_send(qsept->qsch, data, len, false);
 }
 
+static unsigned int qcom_smd_poll(struct rpmsg_endpoint *ept,
+				  struct file *filp, poll_table *wait)
+{
+	struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
+	struct qcom_smd_channel *channel = qsept->qsch;
+	unsigned int mask = 0;
+
+	poll_wait(filp, &channel->fblockread_event, wait);
+
+	if (qcom_smd_get_tx_avail(channel) > 20)
+		mask |= POLLOUT | POLLWRNORM;
+
+	return mask;
+}
+
 /*
  * Finds the device_node for the smd child interested in this channel.
  */
@@ -951,6 +966,7 @@  static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops = {
 	.destroy_ept = qcom_smd_destroy_ept,
 	.send = qcom_smd_send,
 	.trysend = qcom_smd_trysend,
+	.poll = qcom_smd_poll,
 };
 
 /*