diff mbox series

[net-next,v3,05/12] net: wwan: t7xx: Add AT and MBIM WWAN ports

Message ID 20211207024711.2765-6-ricardo.martinez@linux.intel.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series net: wwan: t7xx: PCIe driver for MediaTek M.2 modem | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers warning 3 maintainers not CCed: linux-mediatek@lists.infradead.org linux-arm-kernel@lists.infradead.org matthias.bgg@gmail.com
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch warning WARNING: added, moved or deleted file(s), does MAINTAINERS need updating? WARNING: line length of 81 exceeds 80 columns WARNING: line length of 82 exceeds 80 columns WARNING: line length of 83 exceeds 80 columns WARNING: line length of 85 exceeds 80 columns WARNING: line length of 86 exceeds 80 columns WARNING: line length of 91 exceeds 80 columns WARNING: line length of 96 exceeds 80 columns WARNING: line length of 99 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline fail Was 0 now: 1

Commit Message

Ricardo Martinez Dec. 7, 2021, 2:47 a.m. UTC
From: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>

Adds AT and MBIM ports to the port proxy infrastructure.
The initialization method is responsible for creating the corresponding
ports using the WWAN framework infrastructure. The implemented WWAN port
operations are start, stop, and TX.

Signed-off-by: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>
Co-developed-by: Ricardo Martinez <ricardo.martinez@linux.intel.com>
Signed-off-by: Ricardo Martinez <ricardo.martinez@linux.intel.com>
---
 drivers/net/wwan/t7xx/Makefile          |   1 +
 drivers/net/wwan/t7xx/t7xx_port_proxy.c |  24 +++
 drivers/net/wwan/t7xx/t7xx_port_proxy.h |   1 +
 drivers/net/wwan/t7xx/t7xx_port_wwan.c  | 258 ++++++++++++++++++++++++
 4 files changed, 284 insertions(+)
 create mode 100644 drivers/net/wwan/t7xx/t7xx_port_wwan.c

Comments

Loic Poulain Dec. 7, 2021, 9:48 a.m. UTC | #1
Hi Ricardo,

Overall, it looks good, but:

On Tue, 7 Dec 2021 at 03:48, Ricardo Martinez
<ricardo.martinez@linux.intel.com> wrote:
>
> From: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>
>
> Adds AT and MBIM ports to the port proxy infrastructure.
> The initialization method is responsible for creating the corresponding
> ports using the WWAN framework infrastructure. The implemented WWAN port
> operations are start, stop, and TX.
>
> Signed-off-by: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>
> Co-developed-by: Ricardo Martinez <ricardo.martinez@linux.intel.com>
> Signed-off-by: Ricardo Martinez <ricardo.martinez@linux.intel.com>
> ---
>  drivers/net/wwan/t7xx/Makefile          |   1 +
>  drivers/net/wwan/t7xx/t7xx_port_proxy.c |  24 +++
>  drivers/net/wwan/t7xx/t7xx_port_proxy.h |   1 +
>  drivers/net/wwan/t7xx/t7xx_port_wwan.c  | 258 ++++++++++++++++++++++++
>  4 files changed, 284 insertions(+)
>  create mode 100644 drivers/net/wwan/t7xx/t7xx_port_wwan.c
>
[...]
> +static int t7xx_port_ctrl_tx(struct wwan_port *port, struct sk_buff *skb)
> +{
> +       struct t7xx_port *port_private = wwan_port_get_drvdata(port);
> +       size_t actual_count = 0, alloc_size = 0, txq_mtu = 0;
> +       struct t7xx_port_static *port_static;
> +       int i, multi_packet = 1, ret = 0;
> +       struct sk_buff *skb_ccci = NULL;
> +       struct t7xx_fsm_ctl *ctl;
> +       enum md_state md_state;
> +       unsigned int count;
> +       bool port_multi;
> +
> +       count = skb->len;
> +       if (!count)
> +               return -EINVAL;
> +
> +       port_static = port_private->port_static;
> +       ctl = port_private->t7xx_dev->md->fsm_ctl;
> +       md_state = t7xx_fsm_get_md_state(ctl);
> +       if (md_state == MD_STATE_WAITING_FOR_HS1 || md_state == MD_STATE_WAITING_FOR_HS2) {
> +               dev_warn(port_private->dev, "Cannot write to %s port when md_state=%d\n",
> +                        port_static->name, md_state);
> +               return -ENODEV;
> +       }
> +
> +       txq_mtu = CLDMA_TXQ_MTU;
> +
> +       if (port_private->flags & PORT_F_USER_HEADER) {
> +               if (port_private->flags & PORT_F_USER_HEADER && count > txq_mtu) {
> +                       dev_err(port_private->dev, "Packet %u larger than MTU on %s port\n",
> +                               count, port_static->name);
> +                       return -ENOMEM;
> +               }
> +
> +               alloc_size = min_t(size_t, txq_mtu, count);
> +               actual_count = alloc_size;
> +       } else {
> +               alloc_size = min_t(size_t, txq_mtu, count + CCCI_H_ELEN);
> +               actual_count = alloc_size - CCCI_H_ELEN;
> +               port_multi = t7xx_port_wwan_multipkt_capable(port_static);
> +               if ((count + CCCI_H_ELEN > txq_mtu) && port_multi)
> +                       multi_packet = DIV_ROUND_UP(count, txq_mtu - CCCI_H_ELEN);
> +       }
> +
> +       for (i = 0; i < multi_packet; i++) {
> +               struct ccci_header *ccci_h = NULL;
> +
> +               if (multi_packet > 1 && multi_packet == i + 1) {
> +                       actual_count = count % (txq_mtu - CCCI_H_ELEN);
> +                       alloc_size = actual_count + CCCI_H_ELEN;
> +               }
> +
> +               skb_ccci = __dev_alloc_skb(alloc_size, GFP_KERNEL);
> +               if (!skb_ccci)
> +                       return -ENOMEM;
> +
> +               ccci_h = skb_put(skb_ccci, CCCI_H_LEN);
> +               ccci_h->packet_header = 0;
> +               ccci_h->packet_len = cpu_to_le32(actual_count + CCCI_H_LEN);
> +               ccci_h->status &= cpu_to_le32(~HDR_FLD_CHN);
> +               ccci_h->status |= cpu_to_le32(FIELD_PREP(HDR_FLD_CHN, port_static->tx_ch));
> +               ccci_h->ex_msg = 0;
> +
> +               memcpy(skb_put(skb_ccci, actual_count), skb->data + i * (txq_mtu - CCCI_H_ELEN),
> +                      actual_count);
> +
> +               t7xx_port_proxy_set_seq_num(port_private, ccci_h);
> +
> +               ret = t7xx_port_send_skb_to_md(port_private, skb_ccci, true);
> +               if (ret)
> +                       goto err_free_skb;
> +
> +               port_private->seq_nums[MTK_TX]++;
> +
> +               if (multi_packet == 1)
> +                       return actual_count;
> +               else if (multi_packet == i + 1)
> +                       return count;

wwan port tx ops is supposed to return 0 on success, and release the
processed skb. In your case it works because wwan core does:

ret = wwan_port_op_tx(port, skb, !!(filp->f_flags & O_NONBLOCK));
if (ret) {
        kfree_skb(skb);
        return ret;
}

So returning a positive value here (count) makes the core enter the
error case, release the skb for you and return your count value to
write fops. Eventually, you land on your feet, but it's not what was
expected from tx ops. You should simply return 0 on success and
release the skb. Alternatively, if you think partial TX is something
we need, it should be somewhat documented in the wwan_port_fops_write
function or tx_ops definition.

Regards,
Loic
Ilpo Järvinen Dec. 16, 2021, 12:25 p.m. UTC | #2
On Mon, 6 Dec 2021, Ricardo Martinez wrote:

> From: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>
> 
> Adds AT and MBIM ports to the port proxy infrastructure.
> The initialization method is responsible for creating the corresponding
> ports using the WWAN framework infrastructure. The implemented WWAN port
> operations are start, stop, and TX.
> 
> Signed-off-by: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>
> Co-developed-by: Ricardo Martinez <ricardo.martinez@linux.intel.com>
> Signed-off-by: Ricardo Martinez <ricardo.martinez@linux.intel.com>

> +static int t7xx_port_ctrl_tx(struct wwan_port *port, struct sk_buff *skb)
> +{
> +	struct t7xx_port *port_private = wwan_port_get_drvdata(port);
> +	size_t actual_count = 0, alloc_size = 0, txq_mtu = 0;
> +	struct t7xx_port_static *port_static;
> +	int i, multi_packet = 1, ret = 0;
> +	struct sk_buff *skb_ccci = NULL;
> +	struct t7xx_fsm_ctl *ctl;
> +	enum md_state md_state;
> +	unsigned int count;
> +	bool port_multi;
> +
> +	count = skb->len;
> +	if (!count)
> +		return -EINVAL;
> +
> +	port_static = port_private->port_static;
> +	ctl = port_private->t7xx_dev->md->fsm_ctl;
> +	md_state = t7xx_fsm_get_md_state(ctl);
> +	if (md_state == MD_STATE_WAITING_FOR_HS1 || md_state == MD_STATE_WAITING_FOR_HS2) {
> +		dev_warn(port_private->dev, "Cannot write to %s port when md_state=%d\n",
> +			 port_static->name, md_state);
> +		return -ENODEV;
> +	}
> +
> +	txq_mtu = CLDMA_TXQ_MTU;
> +
> +	if (port_private->flags & PORT_F_USER_HEADER) {
> +		if (port_private->flags & PORT_F_USER_HEADER && count > txq_mtu) {
> +			dev_err(port_private->dev, "Packet %u larger than MTU on %s port\n",
> +				count, port_static->name);
> +			return -ENOMEM;
> +		}
> +
> +		alloc_size = min_t(size_t, txq_mtu, count);
> +		actual_count = alloc_size;
> +	} else {
> +		alloc_size = min_t(size_t, txq_mtu, count + CCCI_H_ELEN);
> +		actual_count = alloc_size - CCCI_H_ELEN;
> +		port_multi = t7xx_port_wwan_multipkt_capable(port_static);
> +		if ((count + CCCI_H_ELEN > txq_mtu) && port_multi)
> +			multi_packet = DIV_ROUND_UP(count, txq_mtu - CCCI_H_ELEN);
> +	}
> +
> +	for (i = 0; i < multi_packet; i++) {
> +		struct ccci_header *ccci_h = NULL;
> +
> +		if (multi_packet > 1 && multi_packet == i + 1) {
> +			actual_count = count % (txq_mtu - CCCI_H_ELEN);
> +			alloc_size = actual_count + CCCI_H_ELEN;
> +		}
> +
> +		skb_ccci = __dev_alloc_skb(alloc_size, GFP_KERNEL);
> +		if (!skb_ccci)
> +			return -ENOMEM;
> +
> +		ccci_h = skb_put(skb_ccci, CCCI_H_LEN);
> +		ccci_h->packet_header = 0;
> +		ccci_h->packet_len = cpu_to_le32(actual_count + CCCI_H_LEN);
> +		ccci_h->status &= cpu_to_le32(~HDR_FLD_CHN);
> +		ccci_h->status |= cpu_to_le32(FIELD_PREP(HDR_FLD_CHN, port_static->tx_ch));
> +		ccci_h->ex_msg = 0;
> +
> +		memcpy(skb_put(skb_ccci, actual_count), skb->data + i * (txq_mtu - CCCI_H_ELEN),
> +		       actual_count);
> +
> +		t7xx_port_proxy_set_seq_num(port_private, ccci_h);
> +
> +		ret = t7xx_port_send_skb_to_md(port_private, skb_ccci, true);
> +		if (ret)
> +			goto err_free_skb;
> +
> +		port_private->seq_nums[MTK_TX]++;
> +
> +		if (multi_packet == 1)
> +			return actual_count;
> +		else if (multi_packet == i + 1)
> +			return count;
> +	}

I'd recommend renaming variables to make it clearer what they count:
- count -> bytes
- actual_count -> actual_bytes
- multi_packet -> packets
Andy Shevchenko Dec. 16, 2021, 12:59 p.m. UTC | #3
On Thu, Dec 16, 2021 at 02:25:47PM +0200, Ilpo Järvinen wrote:
> On Mon, 6 Dec 2021, Ricardo Martinez wrote:

> > +		if (multi_packet == 1)
> > +			return actual_count;
> > +		else if (multi_packet == i + 1)

On top of that redundant 'else' here.

> > +			return count;
> > +	}
> 
> I'd recommend renaming variables to make it clearer what they count:
> - count -> bytes
> - actual_count -> actual_bytes
> - multi_packet -> packets
diff mbox series

Patch

diff --git a/drivers/net/wwan/t7xx/Makefile b/drivers/net/wwan/t7xx/Makefile
index 63e1c67b82b5..9eec2e2472fb 100644
--- a/drivers/net/wwan/t7xx/Makefile
+++ b/drivers/net/wwan/t7xx/Makefile
@@ -12,3 +12,4 @@  mtk_t7xx-y:=	t7xx_pci.o \
 		t7xx_hif_cldma.o  \
 		t7xx_port_proxy.o  \
 		t7xx_port_ctrl_msg.o \
+		t7xx_port_wwan.o \
diff --git a/drivers/net/wwan/t7xx/t7xx_port_proxy.c b/drivers/net/wwan/t7xx/t7xx_port_proxy.c
index 67219319e9f7..4c6f255c4d2f 100644
--- a/drivers/net/wwan/t7xx/t7xx_port_proxy.c
+++ b/drivers/net/wwan/t7xx/t7xx_port_proxy.c
@@ -51,6 +51,30 @@ 
 
 static struct t7xx_port_static t7xx_md_ports[] = {
 	{
+		.tx_ch = PORT_CH_UART2_TX,
+		.rx_ch = PORT_CH_UART2_RX,
+		.txq_index = Q_IDX_AT_CMD,
+		.rxq_index = Q_IDX_AT_CMD,
+		.txq_exp_index = 0xff,
+		.rxq_exp_index = 0xff,
+		.path_id = ID_CLDMA1,
+		.flags = PORT_F_RX_CHAR_NODE,
+		.ops = &wwan_sub_port_ops,
+		.name = "AT",
+		.port_type = WWAN_PORT_AT,
+	}, {
+		.tx_ch = PORT_CH_MBIM_TX,
+		.rx_ch = PORT_CH_MBIM_RX,
+		.txq_index = Q_IDX_MBIM,
+		.rxq_index = Q_IDX_MBIM,
+		.txq_exp_index = 0,
+		.rxq_exp_index = 0,
+		.path_id = ID_CLDMA1,
+		.flags = PORT_F_RX_CHAR_NODE,
+		.ops = &wwan_sub_port_ops,
+		.name = "MBIM",
+		.port_type = WWAN_PORT_MBIM,
+	}, {
 		.tx_ch = PORT_CH_CONTROL_TX,
 		.rx_ch = PORT_CH_CONTROL_RX,
 		.txq_index = Q_IDX_CTRL,
diff --git a/drivers/net/wwan/t7xx/t7xx_port_proxy.h b/drivers/net/wwan/t7xx/t7xx_port_proxy.h
index 06ccda839445..1f49d1ef6bad 100644
--- a/drivers/net/wwan/t7xx/t7xx_port_proxy.h
+++ b/drivers/net/wwan/t7xx/t7xx_port_proxy.h
@@ -67,6 +67,7 @@  struct port_msg {
 #define PORT_ENUM_VER_MISMATCH	0x00657272
 
 /* Port operations mapping */
+extern struct port_ops wwan_sub_port_ops;
 extern struct port_ops ctl_port_ops;
 
 int t7xx_port_proxy_send_skb(struct t7xx_port *port, struct sk_buff *skb);
diff --git a/drivers/net/wwan/t7xx/t7xx_port_wwan.c b/drivers/net/wwan/t7xx/t7xx_port_wwan.c
new file mode 100644
index 000000000000..79831291e490
--- /dev/null
+++ b/drivers/net/wwan/t7xx/t7xx_port_wwan.c
@@ -0,0 +1,258 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021, MediaTek Inc.
+ * Copyright (c) 2021, Intel Corporation.
+ *
+ * Authors:
+ *  Amir Hanania <amir.hanania@intel.com>
+ *  Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>
+ *  Haijun Liu <haijun.liu@mediatek.com>
+ *  Moises Veleta <moises.veleta@intel.com>
+ *  Ricardo Martinez<ricardo.martinez@linux.intel.com>
+ *
+ * Contributors:
+ *  Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ *  Chiranjeevi Rapolu <chiranjeevi.rapolu@intel.com>
+ *  Eliot Lee <eliot.lee@intel.com>
+ *  Sreehari Kancharla <sreehari.kancharla@intel.com>
+ */
+
+#include <linux/atomic.h>
+#include <linux/bitfield.h>
+#include <linux/dev_printk.h>
+#include <linux/err.h>
+#include <linux/gfp.h>
+#include <linux/minmax.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/wwan.h>
+
+#include "t7xx_common.h"
+#include "t7xx_port.h"
+#include "t7xx_port_proxy.h"
+#include "t7xx_state_monitor.h"
+
+static int t7xx_port_ctrl_start(struct wwan_port *port)
+{
+	struct t7xx_port *port_mtk = wwan_port_get_drvdata(port);
+
+	if (atomic_read(&port_mtk->usage_cnt))
+		return -EBUSY;
+
+	atomic_inc(&port_mtk->usage_cnt);
+	return 0;
+}
+
+static void t7xx_port_ctrl_stop(struct wwan_port *port)
+{
+	struct t7xx_port *port_mtk = wwan_port_get_drvdata(port);
+
+	atomic_dec(&port_mtk->usage_cnt);
+}
+
+static inline bool t7xx_port_wwan_multipkt_capable(struct t7xx_port_static *port)
+{
+	return port->tx_ch == PORT_CH_MBIM_TX ||
+		(port->tx_ch >= PORT_CH_DSS0_TX && port->tx_ch <= PORT_CH_DSS7_TX);
+}
+
+static int t7xx_port_ctrl_tx(struct wwan_port *port, struct sk_buff *skb)
+{
+	struct t7xx_port *port_private = wwan_port_get_drvdata(port);
+	size_t actual_count = 0, alloc_size = 0, txq_mtu = 0;
+	struct t7xx_port_static *port_static;
+	int i, multi_packet = 1, ret = 0;
+	struct sk_buff *skb_ccci = NULL;
+	struct t7xx_fsm_ctl *ctl;
+	enum md_state md_state;
+	unsigned int count;
+	bool port_multi;
+
+	count = skb->len;
+	if (!count)
+		return -EINVAL;
+
+	port_static = port_private->port_static;
+	ctl = port_private->t7xx_dev->md->fsm_ctl;
+	md_state = t7xx_fsm_get_md_state(ctl);
+	if (md_state == MD_STATE_WAITING_FOR_HS1 || md_state == MD_STATE_WAITING_FOR_HS2) {
+		dev_warn(port_private->dev, "Cannot write to %s port when md_state=%d\n",
+			 port_static->name, md_state);
+		return -ENODEV;
+	}
+
+	txq_mtu = CLDMA_TXQ_MTU;
+
+	if (port_private->flags & PORT_F_USER_HEADER) {
+		if (port_private->flags & PORT_F_USER_HEADER && count > txq_mtu) {
+			dev_err(port_private->dev, "Packet %u larger than MTU on %s port\n",
+				count, port_static->name);
+			return -ENOMEM;
+		}
+
+		alloc_size = min_t(size_t, txq_mtu, count);
+		actual_count = alloc_size;
+	} else {
+		alloc_size = min_t(size_t, txq_mtu, count + CCCI_H_ELEN);
+		actual_count = alloc_size - CCCI_H_ELEN;
+		port_multi = t7xx_port_wwan_multipkt_capable(port_static);
+		if ((count + CCCI_H_ELEN > txq_mtu) && port_multi)
+			multi_packet = DIV_ROUND_UP(count, txq_mtu - CCCI_H_ELEN);
+	}
+
+	for (i = 0; i < multi_packet; i++) {
+		struct ccci_header *ccci_h = NULL;
+
+		if (multi_packet > 1 && multi_packet == i + 1) {
+			actual_count = count % (txq_mtu - CCCI_H_ELEN);
+			alloc_size = actual_count + CCCI_H_ELEN;
+		}
+
+		skb_ccci = __dev_alloc_skb(alloc_size, GFP_KERNEL);
+		if (!skb_ccci)
+			return -ENOMEM;
+
+		ccci_h = skb_put(skb_ccci, CCCI_H_LEN);
+		ccci_h->packet_header = 0;
+		ccci_h->packet_len = cpu_to_le32(actual_count + CCCI_H_LEN);
+		ccci_h->status &= cpu_to_le32(~HDR_FLD_CHN);
+		ccci_h->status |= cpu_to_le32(FIELD_PREP(HDR_FLD_CHN, port_static->tx_ch));
+		ccci_h->ex_msg = 0;
+
+		memcpy(skb_put(skb_ccci, actual_count), skb->data + i * (txq_mtu - CCCI_H_ELEN),
+		       actual_count);
+
+		t7xx_port_proxy_set_seq_num(port_private, ccci_h);
+
+		ret = t7xx_port_send_skb_to_md(port_private, skb_ccci, true);
+		if (ret)
+			goto err_free_skb;
+
+		port_private->seq_nums[MTK_TX]++;
+
+		if (multi_packet == 1)
+			return actual_count;
+		else if (multi_packet == i + 1)
+			return count;
+	}
+
+err_free_skb:
+	if (ret != -ENOMEM) {
+		dev_err(port_private->dev, "Write error on %s port, %d\n", port_static->name, ret);
+		dev_kfree_skb_any(skb_ccci);
+	}
+
+	return ret;
+}
+
+static const struct wwan_port_ops wwan_ops = {
+	.start = t7xx_port_ctrl_start,
+	.stop = t7xx_port_ctrl_stop,
+	.tx = t7xx_port_ctrl_tx,
+};
+
+static int t7xx_port_wwan_init(struct t7xx_port *port)
+{
+	struct t7xx_port_static *port_static = port->port_static;
+
+	port->rx_length_th = MAX_RX_QUEUE_LENGTH;
+	port->flags |= PORT_F_RX_ADJUST_HEADER;
+
+	if (port_static->rx_ch == PORT_CH_UART2_RX)
+		port->flags |= PORT_F_RX_CH_TRAFFIC;
+
+	if (port_static->port_type != WWAN_PORT_UNKNOWN) {
+		port->wwan_port = wwan_create_port(port->dev, port_static->port_type,
+						   &wwan_ops, port);
+		if (IS_ERR(port->wwan_port))
+			return PTR_ERR(port->wwan_port);
+	} else {
+		port->wwan_port = NULL;
+	}
+
+	return 0;
+}
+
+static void t7xx_port_wwan_uninit(struct t7xx_port *port)
+{
+	if (port->wwan_port) {
+		if (port->chn_crt_stat) {
+			spin_lock(&port->port_update_lock);
+			port->chn_crt_stat = false;
+			spin_unlock(&port->port_update_lock);
+		}
+
+		wwan_remove_port(port->wwan_port);
+		port->wwan_port = NULL;
+	}
+}
+
+static int t7xx_port_wwan_recv_skb(struct t7xx_port *port, struct sk_buff *skb)
+{
+	struct t7xx_port_static *port_static = port->port_static;
+
+	if (port->flags & PORT_F_RX_CHAR_NODE) {
+		if (!atomic_read(&port->usage_cnt)) {
+			dev_err_ratelimited(port->dev, "Port %s is not opened, drop packets\n",
+					    port_static->name);
+			return -ENETDOWN;
+		}
+	}
+
+	return t7xx_port_recv_skb(port, skb);
+}
+
+static void port_status_update(struct t7xx_port *port)
+{
+	if (port->flags & PORT_F_RX_CHAR_NODE) {
+		if (port->chan_enable) {
+			port->flags &= ~PORT_F_RX_ALLOW_DROP;
+		} else {
+			port->flags |= PORT_F_RX_ALLOW_DROP;
+			spin_lock(&port->port_update_lock);
+			port->chn_crt_stat = false;
+			spin_unlock(&port->port_update_lock);
+		}
+	}
+}
+
+static int t7xx_port_wwan_enable_chl(struct t7xx_port *port)
+{
+	spin_lock(&port->port_update_lock);
+	port->chan_enable = true;
+	spin_unlock(&port->port_update_lock);
+
+	if (port->chn_crt_stat != port->chan_enable)
+		port_status_update(port);
+
+	return 0;
+}
+
+static int t7xx_port_wwan_disable_chl(struct t7xx_port *port)
+{
+	spin_lock(&port->port_update_lock);
+	port->chan_enable = false;
+	spin_unlock(&port->port_update_lock);
+
+	if (port->chn_crt_stat != port->chan_enable)
+		port_status_update(port);
+
+	return 0;
+}
+
+static void t7xx_port_wwan_md_state_notify(struct t7xx_port *port, unsigned int state)
+{
+	if (state == MD_STATE_READY)
+		port_status_update(port);
+}
+
+struct port_ops wwan_sub_port_ops = {
+	.init = &t7xx_port_wwan_init,
+	.recv_skb = &t7xx_port_wwan_recv_skb,
+	.uninit = &t7xx_port_wwan_uninit,
+	.enable_chl = &t7xx_port_wwan_enable_chl,
+	.disable_chl = &t7xx_port_wwan_disable_chl,
+	.md_state_notify = &t7xx_port_wwan_md_state_notify,
+};