bus: fsl-mc: add the fsl_mc_get_endpoint function

Using the newly added fsl_mc_get_endpoint function a fsl-mc driver can
find its associated endpoint (another object at the other link of a MC
firmware link).

The API will be used in the following patch in order to discover the
connected DPMAC object of a DPNI.

Also, the fsl_mc_device_lookup function is made available to the entire
fsl-mc bus driver and not just for the dprc driver.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 53 insertions, 0 deletions

diff --git a/drivers/bus/fsl-mc/dprc.c b/drivers/bus/fsl-mc/dprc.c
index 0fe3f52ae0de..602f030d84eb 100644
--- a/drivers/bus/fsl-mc/dprc.c
+++ b/drivers/bus/fsl-mc/dprc.c
@@ -554,3 +554,56 @@ int dprc_get_container_id(struct fsl_mc_io *mc_io,
 
 	return 0;
 }
+
+/**
+ * dprc_get_connection() - Get connected endpoint and link status if connection
+ *			exists.
+ * @mc_io:	Pointer to MC portal's I/O object
+ * @cmd_flags:	Command flags; one or more of 'MC_CMD_FLAG_'
+ * @token:	Token of DPRC object
+ * @endpoint1:	Endpoint 1 configuration parameters
+ * @endpoint2:	Returned endpoint 2 configuration parameters
+ * @state:	Returned link state:
+ *		1 - link is up;
+ *		0 - link is down;
+ *		-1 - no connection (endpoint2 information is irrelevant)
+ *
+ * Return:     '0' on Success; -ENOTCONN if connection does not exist.
+ */
+int dprc_get_connection(struct fsl_mc_io *mc_io,
+			u32 cmd_flags,
+			u16 token,
+			const struct dprc_endpoint *endpoint1,
+			struct dprc_endpoint *endpoint2,
+			int *state)
+{
+	struct dprc_cmd_get_connection *cmd_params;
+	struct dprc_rsp_get_connection *rsp_params;
+	struct fsl_mc_command cmd = { 0 };
+	int err, i;
+
+	/* prepare command */
+	cmd.header = mc_encode_cmd_header(DPRC_CMDID_GET_CONNECTION,
+					  cmd_flags,
+					  token);
+	cmd_params = (struct dprc_cmd_get_connection *)cmd.params;
+	cmd_params->ep1_id = cpu_to_le32(endpoint1->id);
+	cmd_params->ep1_interface_id = cpu_to_le16(endpoint1->if_id);
+	for (i = 0; i < 16; i++)
+		cmd_params->ep1_type[i] = endpoint1->type[i];
+
+	/* send command to mc */
+	err = mc_send_command(mc_io, &cmd);
+	if (err)
+		return -ENOTCONN;
+
+	/* retrieve response parameters */
+	rsp_params = (struct dprc_rsp_get_connection *)cmd.params;
+	endpoint2->id = le32_to_cpu(rsp_params->ep2_id);
+	endpoint2->if_id = le16_to_cpu(rsp_params->ep2_interface_id);
+	*state = le32_to_cpu(rsp_params->state);
+	for (i = 0; i < 16; i++)
+		endpoint2->type[i] = rsp_params->ep2_type[i];
+
+	return 0;
+}