[PATCH v9 2/6] net: wwan: t9xx: Add control plane transaction layer

[Jack Wu via B4 Relay <devnull+jackbb_wu.compal.com@kernel.org>]

From: Jack Wu <jackbb_wu@compal.com>

Introduce the control plane and transaction layer framework
for the T9XX WWAN driver. This patch adds the core data
structures (mtk_ctrl_blk, mtk_ctrl_trans) and initialization
entry points that subsequent patches build upon.

The control plane block (ctrl_blk) serves as the central
context for managing the transaction layer, port layer, and
FSM interactions. The actual DMA engine and TX/RX service
implementations are added in subsequent patches.

Signed-off-by: Jack Wu <jackbb_wu@compal.com>
---
 drivers/net/wwan/t9xx/Makefile              |  1 +
 drivers/net/wwan/t9xx/mtk_ctrl_plane.c      | 44 +++++++++++++++++++++++++++++
 drivers/net/wwan/t9xx/mtk_ctrl_plane.h      | 22 +++++++++++++++
 drivers/net/wwan/t9xx/mtk_dev.h             |  3 ++
 drivers/net/wwan/t9xx/pcie/mtk_pci.c        |  1 +
 drivers/net/wwan/t9xx/pcie/mtk_trans_ctrl.h | 21 ++++++++++++++
 6 files changed, 92 insertions(+)

diff --git a/drivers/net/wwan/t9xx/Makefile b/drivers/net/wwan/t9xx/Makefile
index bd6063c85c2b..0a07507f1ddf 100644
--- a/drivers/net/wwan/t9xx/Makefile
+++ b/drivers/net/wwan/t9xx/Makefile
@@ -6,4 +6,5 @@ ccflags-y += -I$(src)
 obj-$(CONFIG_MTK_T9XX) += mtk_t9xx.o
 
 mtk_t9xx-y := \
+	mtk_ctrl_plane.o \
 	pcie/mtk_pci.o
diff --git a/drivers/net/wwan/t9xx/mtk_ctrl_plane.c b/drivers/net/wwan/t9xx/mtk_ctrl_plane.c
new file mode 100644
index 000000000000..fa2ab8c3e757
--- /dev/null
+++ b/drivers/net/wwan/t9xx/mtk_ctrl_plane.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022, MediaTek Inc.
+ * Copyright (c) 2022-2023, Intel Corporation.
+ */
+
+#include <linux/device.h>
+
+#include "mtk_ctrl_plane.h"
+
+/**
+ * mtk_ctrl_init() - Initialize the control plane block.
+ * @mdev: Pointer to the MTK modem device.
+ *
+ * Allocates and initializes the control plane block
+ * associated with @mdev.
+ *
+ * Return: 0 on success, -ENOMEM on allocation failure.
+ */
+int mtk_ctrl_init(struct mtk_md_dev *mdev)
+{
+	struct mtk_ctrl_blk *ctrl_blk;
+
+	ctrl_blk = devm_kzalloc(mdev->dev, sizeof(*ctrl_blk), GFP_KERNEL);
+	if (!ctrl_blk)
+		return -ENOMEM;
+
+	ctrl_blk->mdev = mdev;
+	mdev->ctrl_blk = ctrl_blk;
+
+	return 0;
+}
+
+/**
+ * mtk_ctrl_exit() - Clean up the control plane block.
+ * @mdev: Pointer to the MTK modem device.
+ *
+ * Clears the control plane block pointer. The allocation
+ * itself is managed by devres and freed on driver detach.
+ */
+void mtk_ctrl_exit(struct mtk_md_dev *mdev)
+{
+	mdev->ctrl_blk = NULL;
+}
diff --git a/drivers/net/wwan/t9xx/mtk_ctrl_plane.h b/drivers/net/wwan/t9xx/mtk_ctrl_plane.h
new file mode 100644
index 000000000000..c141876ef95d
--- /dev/null
+++ b/drivers/net/wwan/t9xx/mtk_ctrl_plane.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0-only
+ *
+ * Copyright (c) 2022, MediaTek Inc.
+ */
+
+#ifndef __MTK_CTRL_PLANE_H__
+#define __MTK_CTRL_PLANE_H__
+
+#include <linux/kref.h>
+#include <linux/skbuff.h>
+
+#include "mtk_dev.h"
+
+struct mtk_ctrl_blk {
+	struct mtk_md_dev *mdev;
+	struct mtk_ctrl_trans *trans;
+};
+
+int mtk_ctrl_init(struct mtk_md_dev *mdev);
+void mtk_ctrl_exit(struct mtk_md_dev *mdev);
+
+#endif /* __MTK_CTRL_PLANE_H__ */
diff --git a/drivers/net/wwan/t9xx/mtk_dev.h b/drivers/net/wwan/t9xx/mtk_dev.h
index 329e5e6695df..84fcd980110b 100644
--- a/drivers/net/wwan/t9xx/mtk_dev.h
+++ b/drivers/net/wwan/t9xx/mtk_dev.h
@@ -31,12 +31,15 @@ enum mtk_dev_evt_d2h {
 	DEV_EVT_D2H_ASYNC_HS_NOTIFY_MD	= BIT(6),
 };
 
+struct mtk_ctrl_blk;
+
 /* mtk_md_dev defines the structure of MTK modem device */
 struct mtk_md_dev {
 	struct device *dev;
 	void *hw_priv;
 	u32 hw_ver;
 	char dev_str[MTK_DEV_STR_LEN];
+	struct mtk_ctrl_blk *ctrl_blk;
 };
 
 #endif /* __MTK_DEV_H__ */
diff --git a/drivers/net/wwan/t9xx/pcie/mtk_pci.c b/drivers/net/wwan/t9xx/pcie/mtk_pci.c
index 34ee823119fc..c2c2b824ff31 100644
--- a/drivers/net/wwan/t9xx/pcie/mtk_pci.c
+++ b/drivers/net/wwan/t9xx/pcie/mtk_pci.c
@@ -12,6 +12,7 @@
 #include <linux/module.h>
 
 #include "mtk_dev.h"
+#include "mtk_trans_ctrl.h"
 #include "mtk_pci.h"
 #include "mtk_pci_reg.h"
 
diff --git a/drivers/net/wwan/t9xx/pcie/mtk_trans_ctrl.h b/drivers/net/wwan/t9xx/pcie/mtk_trans_ctrl.h
new file mode 100644
index 000000000000..d6de4c43b529
--- /dev/null
+++ b/drivers/net/wwan/t9xx/pcie/mtk_trans_ctrl.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0-only
+ *
+ * Copyright (c) 2022, MediaTek Inc.
+ */
+
+#ifndef __MTK_TRANS_CTRL_H__
+#define __MTK_TRANS_CTRL_H__
+
+#include <linux/kref.h>
+#include <linux/list.h>
+#include <linux/skbuff.h>
+#include <linux/types.h>
+
+#include "mtk_dev.h"
+
+struct mtk_ctrl_trans {
+	struct mtk_ctrl_blk *ctrl_blk;
+	struct mtk_md_dev *mdev;
+};
+
+#endif

-- 
2.34.1