[PATCH v5 2/5] remoteproc: imx_rproc: Populate devices under "rpmsg" subnode

Shenwei Wang
2025-11-04T20:34:38Z

Register the RPMsg channel driver and populate remote devices defined
under the "rpmsg" subnode upon receiving their notification messages.

The following illustrates the expected DTS layout structure:

cm33: remoteproc-cm33 {
compatible = "fsl,imx8ulp-cm33";

rpmsg {
rpmsg-io-channel {
gpio@0 {
compatible = "fsl,imx-rpmsg-gpio";
reg = <0>;
};

gpio@1 {
compatible = "fsl,imx-rpmsg-gpio";
reg = <1>;
};

...
};

rpmsg-i2c-channel {
i2c@0 {
compatible = "fsl,imx-rpmsg-i2c";
reg = <0>;
};
};

...
};
};

Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
---
drivers/remoteproc/imx_rproc.c | 146 ++++++++++++++++++++++++++++++++
include/linux/rpmsg/imx_rpmsg.h | 48 +++++++++++
2 files changed, 194 insertions(+)
create mode 100644 include/linux/rpmsg/imx_rpmsg.h

diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c
index a6eef0080ca9..e21a7980c490 100644
--- a/drivers/remoteproc/imx_rproc.c
+++ b/drivers/remoteproc/imx_rproc.c
@@ -8,6 +8,7 @@
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/firmware/imx/sci.h>
+#include <linux/rpmsg/imx_rpmsg.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mailbox_client.h>
@@ -15,6 +16,8 @@
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
#include <linux/of_reserved_mem.h>
#include <linux/platform_device.h>
#include <linux/pm_domain.h>
@@ -22,6 +25,7 @@
#include <linux/reboot.h>
#include <linux/regmap.h>
#include <linux/remoteproc.h>
+#include <linux/rpmsg.h>
#include <linux/workqueue.h>

#include "imx_rproc.h"
@@ -1084,6 +1088,144 @@ static int imx_rproc_sys_off_handler(struct sys_off_data *data)
return NOTIFY_DONE;
}

+struct imx_rpmsg_driver {
+ struct rpmsg_driver rpdrv;
+ void *driver_data;
+};
+
+static char *channel_device_map[][2] = {
+ {"rpmsg-io-channel", "fsl,imx-rpmsg-gpio"},
+ {"rpmsg-i2c-channel", "fsl,imx-rpmsg-i2c"},
+};
+
+static int imx_rpmsg_endpoint_cb(struct rpmsg_device *rpdev, void *data,
+ int len, void *priv, u32 src)
+{
+ struct imx_rpmsg_driver_data *drvdata;
+
+ drvdata = dev_get_drvdata(&rpdev->dev);
+ if (drvdata && drvdata->rx_callback)
+ return drvdata->rx_callback(rpdev, data, len, priv, src);
+
+ return 0;
+}
+
+static void imx_rpmsg_endpoint_remove(struct rpmsg_device *rpdev)
+{
+ of_platform_depopulate(&rpdev->dev);
+}
+
+static int imx_rpmsg_endpoint_probe(struct rpmsg_device *rpdev)
+{
+ struct imx_rpmsg_driver_data *drvdata;
+ struct imx_rpmsg_driver *imx_rpdrv;
+ struct device *dev = &rpdev->dev;
+ struct of_dev_auxdata *auxdata;
+ struct rpmsg_driver *rpdrv;
+ int i;
+
+ rpdrv = container_of(dev->driver, struct rpmsg_driver, drv);
+ imx_rpdrv = container_of(rpdrv, struct imx_rpmsg_driver, rpdrv);
+
+ if (!imx_rpdrv->driver_data)
+ return -EINVAL;
+
+ drvdata = devm_kmemdup(dev, imx_rpdrv->driver_data, sizeof(*drvdata), GFP_KERNEL);
+ if (!drvdata)
+ return -ENOMEM;
+
+ i = drvdata->map_idx;
+ if (i >= ARRAY_SIZE(channel_device_map))
+ return -ENODEV;
+
+ auxdata = devm_kzalloc(dev, sizeof(*auxdata) * 2, GFP_KERNEL);
+ if (!auxdata)
+ return -ENOMEM;
+
+ drvdata->rpdev = rpdev;
+ auxdata[0].compatible = channel_device_map[i][1];
+ auxdata[0].platform_data = drvdata;
+ dev_set_drvdata(dev, drvdata);
+
+ of_platform_populate(drvdata->channel_node, NULL, auxdata, dev);
+ of_node_put(drvdata->channel_node);
+
+ return 0;
+}
+
+static int imx_of_rpmsg_is_in_map(const char *name)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(channel_device_map); i++) {
+ if (strcmp(name, channel_device_map[i][0]) == 0)
+ return i;
+ }
+
+ return -1;
+}
+
+static int imx_of_rpmsg_register_rpdriver(struct device_node *channel,
+ struct device *dev, int idx)
+{
+ struct imx_rpmsg_driver_data *driver_data;
+ struct imx_rpmsg_driver *rp_driver;
+ struct rpmsg_device_id *rpdev_id;
+
+ rpdev_id = devm_kzalloc(dev, sizeof(*rpdev_id) * 2, GFP_KERNEL);
+ if (!rpdev_id)
+ return -ENOMEM;
+
+ strscpy(rpdev_id[0].name, channel_device_map[idx][0], RPMSG_NAME_SIZE);
+
+ rp_driver = devm_kzalloc(dev, sizeof(*rp_driver), GFP_KERNEL);
+ if (!rp_driver)
+ return -ENOMEM;
+
+ driver_data = devm_kzalloc(dev, sizeof(*driver_data), GFP_KERNEL);
+ if (!driver_data)
+ return -ENOMEM;
+
+ driver_data->rproc_name = dev->of_node->name;
+ driver_data->channel_node = channel;
+ driver_data->map_idx = idx;
+
+ rp_driver->rpdrv.drv.name = channel_device_map[idx][0];
+ rp_driver->rpdrv.id_table = rpdev_id;
+ rp_driver->rpdrv.probe = imx_rpmsg_endpoint_probe;
+ rp_driver->rpdrv.remove = imx_rpmsg_endpoint_remove;
+ rp_driver->rpdrv.callback = imx_rpmsg_endpoint_cb;
+ rp_driver->driver_data = driver_data;
+
+ register_rpmsg_driver(&rp_driver->rpdrv);
+
+ return 0;
+}
+
+static int imx_of_rpmsg_node_init(struct platform_device *pdev)
+{
+ struct device_node *np __free(device_node);
+ struct device *dev = &pdev->dev;
+ int idx, ret;
+
+ np = of_get_child_by_name(dev->of_node, "rpmsg");
+ if (!np)
+ return 0;
+
+ for_each_child_of_node_scoped(np, child) {
+ idx = imx_of_rpmsg_is_in_map(child->name);
+ if (idx < 0)
+ ret = of_platform_default_populate(child, NULL, dev);
+ else
+ ret = imx_of_rpmsg_register_rpdriver(child, dev, idx);
+
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
static int imx_rproc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -1177,6 +1319,10 @@ static int imx_rproc_probe(struct platform_device *pdev)
goto err_put_clk;
}

+ ret = imx_of_rpmsg_node_init(pdev);
+ if (ret < 0)
+ dev_info(dev, "populating 'rpmsg' node failed\n");
+
return 0;

err_put_clk:
diff --git a/include/linux/rpmsg/imx_rpmsg.h b/include/linux/rpmsg/imx_rpmsg.h
new file mode 100644
index 000000000000..04a5ad2d4a1d
--- /dev/null
+++ b/include/linux/rpmsg/imx_rpmsg.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright 2025 NXP */
+
+/*
+ * @file linux/imx_rpmsg.h
+ *
+ * @brief Global header file for iMX RPMSG
+ *
+ * @ingroup RPMSG
+ */
+#ifndef __LINUX_IMX_RPMSG_H__
+#define __LINUX_IMX_RPMSG_H__
+
+/* Category define */
+#define IMX_RMPSG_LIFECYCLE 1
+#define IMX_RPMSG_PMIC 2
+#define IMX_RPMSG_AUDIO 3
+#define IMX_RPMSG_KEY 4
+#define IMX_RPMSG_GPIO 5
+#define IMX_RPMSG_RTC 6
+#define IMX_RPMSG_SENSOR 7
+
+/* rpmsg version */
+#define IMX_RMPSG_MAJOR 1
+#define IMX_RMPSG_MINOR 0
+
+#define MAX_DEV_PER_CHANNEL 10
+
+struct imx_rpmsg_head {
+ u8 cate; /* Category */
+ u8 major; /* Major version */
+ u8 minor; /* Minor version */
+ u8 type; /* Message type */
+ u8 cmd; /* Command code */
+ u8 reserved[5];
+} __packed;
+
+struct imx_rpmsg_driver_data {
+ int map_idx;
+ const char *rproc_name;
+ struct rpmsg_device *rpdev;
+ struct device_node *channel_node;
+ int (*rx_callback)(struct rpmsg_device *rpdev, void *data,
+ int len, void *priv, u32 src);
+ void *channel_devices[MAX_DEV_PER_CHANNEL];
+};
+
+#endif /* __LINUX_IMX_RPMSG_H__ */
--
2.43.0