[PATCH v7 10/12] rpmsg: char: Introduce the "rpmsg-raw" channel

From: Arnaud Pouliquen
Date: Mon Nov 08 2021 - 09:21:02 EST


Allows to probe the endpoint device on a remote name service announcement,
by registering a rpmsg_driverfor the "rpmsg-raw" channel.

With this patch the /dev/rpmsgX interface can be instantiated by the remote
firmware.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxxxxxxx>
---
drivers/rpmsg/rpmsg_char.c | 64 ++++++++++++++++++++++++++++++++++++++
drivers/rpmsg/rpmsg_ctrl.c | 7 +++--
2 files changed, 69 insertions(+), 2 deletions(-)

diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index 6a01e8e1c111..dd754c870ba1 100644
--- a/drivers/rpmsg/rpmsg_char.c
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -432,6 +432,58 @@ int rpmsg_chrdev_eptdev_create(struct rpmsg_device *rpdev, struct device *parent
}
EXPORT_SYMBOL(rpmsg_chrdev_eptdev_create);

+static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev)
+{
+ struct rpmsg_channel_info chinfo;
+ struct rpmsg_eptdev *eptdev;
+ struct device *dev = &rpdev->dev;
+
+ memcpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE);
+ chinfo.src = rpdev->src;
+ chinfo.dst = rpdev->dst;
+
+ eptdev = rpmsg_chrdev_eptdev_alloc(rpdev, dev);
+ if (IS_ERR(eptdev))
+ return PTR_ERR(eptdev);
+
+ /*
+ * Create the default endpoint associated to the rpmsg device and provide rpmsg_eptdev
+ * structure as callback private data.
+ * Do not allow the creation and release of an endpoint on /dev/rpmsgX open and close,
+ * reuse the default endpoint instead
+ */
+ eptdev->default_ept = rpmsg_create_default_ept(rpdev, rpmsg_ept_cb, eptdev, chinfo);
+ if (!eptdev->default_ept) {
+ dev_err(&rpdev->dev, "failed to create %s\n", chinfo.name);
+ put_device(dev);
+ kfree(eptdev);
+ return -EINVAL;
+ }
+
+ return rpmsg_chrdev_eptdev_add(eptdev, chinfo);
+}
+
+static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev)
+{
+ int ret;
+
+ ret = device_for_each_child(&rpdev->dev, NULL, rpmsg_chrdev_eptdev_destroy);
+ if (ret)
+ dev_warn(&rpdev->dev, "failed to destroy endpoints: %d\n", ret);
+}
+
+static struct rpmsg_device_id rpmsg_chrdev_id_table[] = {
+ { .name = "rpmsg-raw" },
+ { },
+};
+
+static struct rpmsg_driver rpmsg_chrdev_driver = {
+ .probe = rpmsg_chrdev_probe,
+ .remove = rpmsg_chrdev_remove,
+ .id_table = rpmsg_chrdev_id_table,
+ .drv.name = "rpmsg_chrdev",
+};
+
static int rpmsg_chrdev_init(void)
{
int ret;
@@ -442,12 +494,24 @@ static int rpmsg_chrdev_init(void)
return ret;
}

+ ret = register_rpmsg_driver(&rpmsg_chrdev_driver);
+ if (ret < 0) {
+ pr_err("rpmsg: failed to register rpmsg raw driver\n");
+ goto free_region;
+ }
+
return 0;
+
+free_region:
+ unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
+
+ return ret;
}
postcore_initcall(rpmsg_chrdev_init);

static void rpmsg_chrdev_exit(void)
{
+ unregister_rpmsg_driver(&rpmsg_chrdev_driver);
unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
}
module_exit(rpmsg_chrdev_exit);
diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c
index 59d2bd264fdb..298e75dc7774 100644
--- a/drivers/rpmsg/rpmsg_ctrl.c
+++ b/drivers/rpmsg/rpmsg_ctrl.c
@@ -10,6 +10,9 @@
* Based on rpmsg performance statistics driver by Michal Simek, which in turn
* was based on TI & Google OMX rpmsg driver.
*/
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/fs.h>
@@ -193,13 +196,13 @@ static int rpmsg_ctrldev_init(void)

ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_ctrl");
if (ret < 0) {
- pr_err("rpmsg: failed to allocate char dev region\n");
+ pr_err("failed to allocate char dev region\n");
return ret;
}

ret = register_rpmsg_driver(&rpmsg_ctrldev_driver);
if (ret < 0) {
- pr_err("rpmsg ctrl: failed to register rpmsg driver\n");
+ pr_err("failed to register rpmsg driver\n");
unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
}

--
2.17.1