[RFC PATCH v2 1/1] rpmsg: add syslog driver

Christian Gmeiner
2021-11-09T08:39:37Z

Allows the remote firmware to log into syslog.

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
---
drivers/rpmsg/Kconfig | 8 +++++
drivers/rpmsg/Makefile | 1 +
drivers/rpmsg/rpmsg_syslog.c | 65 ++++++++++++++++++++++++++++++++++++
3 files changed, 74 insertions(+)
create mode 100644 drivers/rpmsg/rpmsg_syslog.c

diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig
index 0b4407abdf13..801f9956ec21 100644
--- a/drivers/rpmsg/Kconfig
+++ b/drivers/rpmsg/Kconfig
@@ -73,4 +73,12 @@ config RPMSG_VIRTIO
select RPMSG_NS
select VIRTIO

+config RPMSG_SYSLOG
+ tristate "SYSLOG device interface"
+ depends on RPMSG
+ help
+ Say Y here to export rpmsg endpoints as device files, usually found
+ in /dev. They make it possible for user-space programs to send and
+ receive rpmsg packets.
+
endmenu
diff --git a/drivers/rpmsg/Makefile b/drivers/rpmsg/Makefile
index 8d452656f0ee..75b2ec7133a5 100644
--- a/drivers/rpmsg/Makefile
+++ b/drivers/rpmsg/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_RPMSG_QCOM_GLINK_RPM) += qcom_glink_rpm.o
obj-$(CONFIG_RPMSG_QCOM_GLINK_SMEM) += qcom_glink_smem.o
obj-$(CONFIG_RPMSG_QCOM_SMD) += qcom_smd.o
obj-$(CONFIG_RPMSG_VIRTIO) += virtio_rpmsg_bus.o
+obj-$(CONFIG_RPMSG_SYSLOG) += rpmsg_syslog.o
diff --git a/drivers/rpmsg/rpmsg_syslog.c b/drivers/rpmsg/rpmsg_syslog.c
new file mode 100644
index 000000000000..b3fdae495fd9
--- /dev/null
+++ b/drivers/rpmsg/rpmsg_syslog.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/rpmsg.h>
+
+static int rpmsg_syslog_cb(struct rpmsg_device *rpdev, void *data, int len,
+ void *priv, u32 src)
+{
+ const char *buffer = data;
+
+ switch (buffer[0]) {
+ case 'e':
+ dev_err(&rpdev->dev, "%s", buffer + 1);
+ break;
+ case 'w':
+ dev_warn(&rpdev->dev, "%s", buffer + 1);
+ break;
+ case 'i':
+ dev_info(&rpdev->dev, "%s", buffer + 1);
+ break;
+ default:
+ dev_info(&rpdev->dev, "%s", buffer);
+ break;
+ }
+
+ return 0;
+}
+
+static int rpmsg_syslog_probe(struct rpmsg_device *rpdev)
+{
+ struct rpmsg_endpoint *syslog_ept;
+ struct rpmsg_channel_info syslog_chinfo = {
+ .src = 42,
+ .dst = 42,
+ .name = "syslog",
+ };
+
+ /*
+ * Create the syslog service endpoint associated to the RPMsg
+ * device. The endpoint will be automatically destroyed when the RPMsg
+ * device will be deleted.
+ */
+ syslog_ept = rpmsg_create_ept(rpdev, rpmsg_syslog_cb, NULL, syslog_chinfo);
+ if (!syslog_ept) {
+ dev_err(&rpdev->dev, "failed to create the syslog ept\n");
+ return -ENOMEM;
+ }
+ rpdev->ept = syslog_ept;
+
+ return 0;
+}
+
+static struct rpmsg_device_id rpmsg_driver_syslog_id_table[] = {
+ { .name = "syslog" },
+ { },
+};
+MODULE_DEVICE_TABLE(rpmsg, rpmsg_driver_syslog_id_table);
+
+static struct rpmsg_driver rpmsg_syslog_client = {
+ .drv.name = KBUILD_MODNAME,
+ .id_table = rpmsg_driver_syslog_id_table,
+ .probe = rpmsg_syslog_probe,
+};
+module_rpmsg_driver(rpmsg_syslog_client);
--
2.33.1