Implement fixed-up message handlers to maintain compatibility with
existing i.MX devices that rely on the NXP legacy RPMSG firmware and
its transport protocol. This ensures backward compatibility and preserves
functionality for deployed NXP systems.
Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
---
drivers/gpio/gpio-rpmsg.c | 143 ++++++++++++++++++++++++++++++++++++++
1 file changed, 143 insertions(+)
diff --git a/drivers/gpio/gpio-rpmsg.c b/drivers/gpio/gpio-rpmsg.c
index 1accf56a0f79..fcfca658cb8d 100644
--- a/drivers/gpio/gpio-rpmsg.c
+++ b/drivers/gpio/gpio-rpmsg.c
@@ -84,6 +84,145 @@ struct rpdev_drvdata {
void *channel_devices[MAX_PORT_PER_CHANNEL];
};
+/* NXP I.MX Legacy GPIO RPMSG protocol */
+#define IMX_RPMSG_CONFIG_INPUT 0
+#define IMX_RPMSG_CONFIG_OUTPUT 1
+#define IMX_RPMSG_GET_LEVEL 2
+#define IMX_RPMSG_GET_DIRECTION 3
+#define IMX_RPMSG_CMD_UNKNOWN 0x7F
+
+#define IMX_RPMSG_TRI_LOW_LEVEL 4
+#define IMX_RPMSG_TRI_HIGH_LEVEL 5
+
+#define IMX_RPMSG_ID 5
+#define IMX_RPMSG_VENDOR 1
+#define IMX_RPMSG_VERSION 0
+
+struct rpmsg_gpio_nxp_packet {
+ u8 id; /* Message ID Code */
+ u8 vendor; /* Vendor ID number */
+ u8 version; /* Protocol version number */
+ u8 type; /* Message type */
+ u8 cmd; /* Command code */
+ u8 reserved[5];
+ u8 line;
+ u8 port_idx;
+ u8 val1;
+ u8 val2;
+};
+
+static struct rpmsg_gpio_packet *
+rpmsg_gpio_imx_recv_fixed_up(struct rpmsg_device *rpdev, void *data)
+{
+ struct rpmsg_gpio_nxp_packet *imx_msg = data;
+ struct rpmsg_gpio_packet *msg;
+ struct rpdev_drvdata *drvdata;
+
+ if (!imx_msg)
+ return NULL;
+
+ drvdata = dev_get_drvdata(&rpdev->dev);
+ if (!drvdata->recv_pkt)
+ drvdata->recv_pkt = devm_kzalloc(&rpdev->dev, sizeof(*msg), GFP_KERNEL);
+
+ if (!drvdata->recv_pkt)
+ return NULL;
+
+ msg = drvdata->recv_pkt;
+
+ msg->type = imx_msg->type;
+ msg->cmd = imx_msg->cmd;
+ msg->port_idx = imx_msg->port_idx;
+ msg->line = imx_msg->line;
+ msg->val1 = imx_msg->val1;
+ msg->val2 = imx_msg->val2;
+
+ switch (imx_msg->cmd) {
+ case IMX_RPMSG_GET_LEVEL:
+ msg->cmd = VIRTIO_GPIO_MSG_GET_VALUE;
+ break;
+
+ case IMX_RPMSG_GET_DIRECTION:
+ msg->cmd = VIRTIO_GPIO_MSG_GET_DIRECTION;
+ break;
+
+ case IMX_RPMSG_CONFIG_OUTPUT:
+ msg->cmd = VIRTIO_GPIO_MSG_SET_DIRECTION;
+ msg->val2 = VIRTIO_GPIO_DIRECTION_OUT;
+ break;
+
+ case IMX_RPMSG_CONFIG_INPUT:
+ msg->cmd = VIRTIO_GPIO_MSG_SET_DIRECTION;
+ msg->val2 = VIRTIO_GPIO_DIRECTION_IN;
+ break;
+
+ default:
+ break;
+ }
+
+ return msg;
+}
+
+static int imx_std_cmd_map[] = {
+ IMX_RPMSG_CMD_UNKNOWN,
+ IMX_RPMSG_CMD_UNKNOWN, /* VIRTIO_GPIO_MSG_GET_NAMES */
+ IMX_RPMSG_GET_DIRECTION, /* VIRTIO_GPIO_MSG_GET_DIRECTION */
+ IMX_RPMSG_CONFIG_INPUT, /* VIRTIO_GPIO_MSG_SET_DIRECTION */
+ IMX_RPMSG_GET_LEVEL, /* VIRTIO_GPIO_MSG_GET_VALUE */
+ IMX_RPMSG_CONFIG_OUTPUT, /* VIRTIO_GPIO_MSG_SET_VALUE */
+ IMX_RPMSG_CONFIG_INPUT /* VIRTIO_GPIO_MSG_IRQ_TYPE */
+};
+
+static int rpmsg_gpio_imx_send_fixed_up(struct rpmsg_gpio_info *info,
+ struct rpmsg_gpio_packet *msg)
+{
+ struct rpmsg_gpio_nxp_packet imx_msg;
+
+ if (msg->cmd >= sizeof(imx_std_cmd_map))
+ return -EINVAL;
+
+ imx_msg.id = IMX_RPMSG_ID;
+ imx_msg.vendor = IMX_RPMSG_VENDOR;
+ imx_msg.version = IMX_RPMSG_VERSION;
+ imx_msg.type = msg->type;
+ imx_msg.cmd = imx_std_cmd_map[msg->cmd];
+ imx_msg.port_idx = msg->port_idx;
+ imx_msg.line = msg->line;
+ imx_msg.val1 = msg->val1;
+ imx_msg.val2 = msg->val2;
+
+ switch (msg->cmd) {
+ case VIRTIO_GPIO_MSG_IRQ_TYPE:
+ switch (msg->val1) {
+ case VIRTIO_GPIO_IRQ_TYPE_LEVEL_HIGH:
+ imx_msg.val1 = IMX_RPMSG_TRI_HIGH_LEVEL;
+ break;
+ case VIRTIO_GPIO_IRQ_TYPE_LEVEL_LOW:
+ imx_msg.val1 = IMX_RPMSG_TRI_LOW_LEVEL;
+ break;
+ default:
+ break;
+ }
+ break;
+
+ case VIRTIO_GPIO_MSG_SET_DIRECTION:
+ imx_msg.val1 = 0;
+ if (msg->val1 == VIRTIO_GPIO_DIRECTION_OUT)
+ imx_msg.cmd = IMX_RPMSG_CONFIG_OUTPUT;
+ break;
+
+ default:
+ break;
+ }
+
+ return rpmsg_send(info->rpdev->ept, &imx_msg, sizeof(imx_msg));
+}
+
+static struct rpmsg_gpio_fixed_up imx_fixed_up_data = {
+ .recv_fixed_up = rpmsg_gpio_imx_recv_fixed_up,
+ .send_fixed_up = rpmsg_gpio_imx_send_fixed_up,
+};
+
static int rpmsg_gpio_send_message(struct rpmsg_gpio_port *port,
struct rpmsg_gpio_packet *msg,
bool sync)
@@ -572,6 +711,10 @@ static const struct of_device_id rpmsg_gpio_dt_ids[] = {
static struct rpmsg_device_id rpmsg_gpio_channel_id_table[] = {
{ .name = "rpmsg-io" },
+ {
+ .name = "rpmsg-io-channel",
+ .driver_data = (kernel_ulong_t)(uintptr_t)&imx_fixed_up_data
+ },
{ },
};
MODULE_DEVICE_TABLE(rpmsg, rpmsg_gpio_channel_id_table);
--
2.43.0> +static struct rpmsg_gpio_fixed_up imx_fixed_up_data = {
> + .recv_fixed_up = rpmsg_gpio_imx_recv_fixed_up,
> + .send_fixed_up = rpmsg_gpio_imx_send_fixed_up,
> +};
> +
> static int rpmsg_gpio_send_message(struct rpmsg_gpio_port *port,
> struct rpmsg_gpio_packet *msg,
> bool sync)
> @@ -572,6 +711,10 @@ static const struct of_device_id rpmsg_gpio_dt_ids[] = {
>
> static struct rpmsg_device_id rpmsg_gpio_channel_id_table[] = {
> { .name = "rpmsg-io" },
> + {
> + .name = "rpmsg-io-channel",
> + .driver_data = (kernel_ulong_t)(uintptr_t)&imx_fixed_up_data
> + },
Its not clear to me how this gets applied. Don't you need a different
compatible? fsl,rpmsg-gpio-legacy or something?
I would also put it behind a CONFIG_ option, and in a different
module. Nobody needs this code other than your legacy products. You
don't need the bloat for your new devices and other vendors don't need
it.
Andrew
Hi Shenwei,
kernel test robot noticed the following build warnings:
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Shenwei-Wang/docs-driver-api-gpio-rpmsg-gpio-driver-over-rpmsg-bus/20260305-052440
base: https://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux.git gpio/for-next
patch link: https://lore.kernel.org/r/20260304211808.1437846-5-shenwei.wang%40nxp.com
patch subject: [PATCH v9 4/5] gpio: rpmsg: add support for NXP legacy firmware protocol
config: x86_64-randconfig-161-20260306 (https://download.01.org/0day-ci/archive/20260306/202603060910.Q5zBquzF-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
smatch: v0.5.0-9004-gb810ac53
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202603060910.Q5zBquzF-lkp@intel.com/
smatch warnings:
drivers/gpio/gpio-rpmsg.c:188 rpmsg_gpio_imx_send_fixed_up() error: buffer overflow 'imx_std_cmd_map' 7 <= 27
vim +/imx_std_cmd_map +188 drivers/gpio/gpio-rpmsg.c
49a0cb20cd49a59 Shenwei Wang 2026-03-04 176 static int rpmsg_gpio_imx_send_fixed_up(struct rpmsg_gpio_info *info,
49a0cb20cd49a59 Shenwei Wang 2026-03-04 177 struct rpmsg_gpio_packet *msg)
49a0cb20cd49a59 Shenwei Wang 2026-03-04 178 {
49a0cb20cd49a59 Shenwei Wang 2026-03-04 179 struct rpmsg_gpio_nxp_packet imx_msg;
49a0cb20cd49a59 Shenwei Wang 2026-03-04 180
49a0cb20cd49a59 Shenwei Wang 2026-03-04 181 if (msg->cmd >= sizeof(imx_std_cmd_map))
This looks like a sizeof() vs ARRAY_SIZE() bug.
49a0cb20cd49a59 Shenwei Wang 2026-03-04 182 return -EINVAL;
49a0cb20cd49a59 Shenwei Wang 2026-03-04 183
49a0cb20cd49a59 Shenwei Wang 2026-03-04 184 imx_msg.id = IMX_RPMSG_ID;
49a0cb20cd49a59 Shenwei Wang 2026-03-04 185 imx_msg.vendor = IMX_RPMSG_VENDOR;
49a0cb20cd49a59 Shenwei Wang 2026-03-04 186 imx_msg.version = IMX_RPMSG_VERSION;
49a0cb20cd49a59 Shenwei Wang 2026-03-04 187 imx_msg.type = msg->type;
49a0cb20cd49a59 Shenwei Wang 2026-03-04 @188 imx_msg.cmd = imx_std_cmd_map[msg->cmd];
^^^^^^^^
Out of bounds.
49a0cb20cd49a59 Shenwei Wang 2026-03-04 189 imx_msg.port_idx = msg->port_idx;
49a0cb20cd49a59 Shenwei Wang 2026-03-04 190 imx_msg.line = msg->line;
49a0cb20cd49a59 Shenwei Wang 2026-03-04 191 imx_msg.val1 = msg->val1;
49a0cb20cd49a59 Shenwei Wang 2026-03-04 192 imx_msg.val2 = msg->val2;
49a0cb20cd49a59 Shenwei Wang 2026-03-04 193
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
From: Frank Li (AI-BOT) <frank.li@nxp.com>
> +static int imx_std_cmd_map[] = {
AI: Should be 'static const int' since this is a read-only lookup table.
> + if (msg->cmd >= sizeof(imx_std_cmd_map))
AI: Use ARRAY_SIZE(imx_std_cmd_map) instead of sizeof() for clarity.
because imx_std_cmd_map is array, AI most likely is correct.
Frank
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