[PATCH V2] firmware: imx: add get resource owner api

[Peng Fan (OSS)]

From: Peng Fan <peng.fan at nxp.com>

Add resource owner management API, this API could be used to check
whether M4 is under control of Linux.

Signed-off-by: Peng Fan <peng.fan at nxp.com>
---

V2:
 Put comments just above function
 Use EOPNOTSUPP as return value

 drivers/firmware/imx/rm.c           | 45 +++++++++++++++++++++++++++++
 include/linux/firmware/imx/svc/rm.h |  5 ++++
 2 files changed, 50 insertions(+)

diff --git a/drivers/firmware/imx/rm.c b/drivers/firmware/imx/rm.c
index a12db6ff323b..d492b99e1c6c 100644
--- a/drivers/firmware/imx/rm.c
+++ b/drivers/firmware/imx/rm.c
@@ -43,3 +43,48 @@ bool imx_sc_rm_is_resource_owned(struct imx_sc_ipc *ipc, u16 resource)
 	return hdr->func;
 }
 EXPORT_SYMBOL(imx_sc_rm_is_resource_owned);
+
+struct imx_sc_msg_rm_get_resource_owner {
+	struct imx_sc_rpc_msg hdr;
+	union {
+		struct {
+			u16 resource;
+		} req;
+		struct {
+			u8 val;
+		} resp;
+	} data;
+} __packed __aligned(4);
+
+/*
+ * This function get @resource partition number
+ *
+ * @param[in]     ipc         IPC handle
+ * @param[in]     resource    resource the control is associated with
+ * @param[out]    pt          pointer to return the partition number
+ *
+ * @return Returns 0 for success and < 0 for errors.
+ */
+int imx_sc_rm_get_resource_owner(struct imx_sc_ipc *ipc, u16 resource, u8 *pt)
+{
+	struct imx_sc_msg_rm_get_resource_owner msg;
+	struct imx_sc_rpc_msg *hdr = &msg.hdr;
+	int ret;
+
+	hdr->ver = IMX_SC_RPC_VERSION;
+	hdr->svc = IMX_SC_RPC_SVC_RM;
+	hdr->func = IMX_SC_RM_FUNC_GET_RESOURCE_OWNER;
+	hdr->size = 2;
+
+	msg.data.req.resource = resource;
+
+	ret = imx_scu_call_rpc(ipc, &msg, true);
+	if (ret)
+		return ret;
+
+	if (pt)
+		*pt = msg.data.resp.val;
+
+	return 0;
+}
+EXPORT_SYMBOL(imx_sc_rm_get_resource_owner);
diff --git a/include/linux/firmware/imx/svc/rm.h b/include/linux/firmware/imx/svc/rm.h
index 456b6a59d29b..31456f897aa9 100644
--- a/include/linux/firmware/imx/svc/rm.h
+++ b/include/linux/firmware/imx/svc/rm.h
@@ -59,11 +59,16 @@ enum imx_sc_rm_func {
 
 #if IS_ENABLED(CONFIG_IMX_SCU)
 bool imx_sc_rm_is_resource_owned(struct imx_sc_ipc *ipc, u16 resource);
+int imx_sc_rm_get_resource_owner(struct imx_sc_ipc *ipc, u16 resource, u8 *pt);
 #else
 static inline bool
 imx_sc_rm_is_resource_owned(struct imx_sc_ipc *ipc, u16 resource)
 {
 	return true;
 }
+static inline int imx_sc_rm_get_resource_owner(struct imx_sc_ipc *ipc, u16 resource, u8 *pt)
+{
+	return -EOPNOTSUPP;
+}
 #endif
 #endif
-- 
2.25.1