net: wwan: t7xx: Add AT and MBIM WWAN ports

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>
Reviewed-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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 \

drivers/net/wwan/t7xx/t7xx_port_proxy.c

@@ -50,6 +50,26 @@
 
 static const struct t7xx_port_conf t7xx_md_port_conf[] = {
 	{
+		.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 = CLDMA_ID_MD,
+		.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,
+		.path_id = CLDMA_ID_MD,
+		.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,

drivers/net/wwan/t7xx/t7xx_port_proxy.h

@@ -84,6 +84,7 @@ struct ctrl_msg_header {
 #define PORT_ENUM_VER_MISMATCH	0x00657272
 
 /* Port operations mapping */
+extern struct port_ops wwan_sub_port_ops;
 extern struct port_ops ctl_port_ops;
 
 void t7xx_port_proxy_reset(struct port_proxy *port_prox);

drivers/net/wwan/t7xx/t7xx_port_wwan.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021, MediaTek Inc.
+ * Copyright (c) 2021-2022, 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_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 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 len, offset, chunk_len = 0, txq_mtu = CLDMA_MTU;
+	const struct t7xx_port_conf *port_conf;
+	struct t7xx_fsm_ctl *ctl;
+	enum md_state md_state;
+
+	len = skb->len;
+	if (!len || !port_private->chan_enable)
+		return -EINVAL;
+
+	port_conf = port_private->port_conf;
+	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_conf->name, md_state);
+		return -ENODEV;
+	}
+
+	for (offset = 0; offset < len; offset += chunk_len) {
+		struct sk_buff *skb_ccci;
+		int ret;
+
+		chunk_len = min(len - offset, txq_mtu - sizeof(struct ccci_header));
+		skb_ccci = t7xx_port_alloc_skb(chunk_len);
+		if (!skb_ccci)
+			return -ENOMEM;
+
+		skb_put_data(skb_ccci, skb->data + offset, chunk_len);
+		ret = t7xx_port_send_skb(port_private, skb_ccci, 0, 0);
+		if (ret) {
+			dev_kfree_skb_any(skb_ccci);
+			dev_err(port_private->dev, "Write error on %s port, %d\n",
+				port_conf->name, ret);
+			return ret;
+		}
+	}
+
+	dev_kfree_skb(skb);
+	return 0;
+}
+
+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)
+{
+	port->rx_length_th = RX_QUEUE_MAXLEN;
+	return 0;
+}
+
+static void t7xx_port_wwan_uninit(struct t7xx_port *port)
+{
+	if (!port->wwan_port)
+		return;
+
+	port->rx_length_th = 0;
+	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)
+{
+	if (!atomic_read(&port->usage_cnt) || !port->chan_enable) {
+		const struct t7xx_port_conf *port_conf = port->port_conf;
+
+		dev_kfree_skb_any(skb);
+		dev_err_ratelimited(port->dev, "Port %s is not opened, drop packets\n",
+				    port_conf->name);
+		/* Dropping skb, caller should not access skb.*/
+		return 0;
+	}
+
+	wwan_port_rx(port->wwan_port, skb);
+	return 0;
+}
+
+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);
+
+	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);
+
+	return 0;
+}
+
+static void t7xx_port_wwan_md_state_notify(struct t7xx_port *port, unsigned int state)
+{
+	const struct t7xx_port_conf *port_conf = port->port_conf;
+
+	if (state != MD_STATE_READY)
+		return;
+
+	if (!port->wwan_port) {
+		port->wwan_port = wwan_create_port(port->dev, port_conf->port_type,
+						   &wwan_ops, port);
+		if (IS_ERR(port->wwan_port))
+			dev_err(port->dev, "Unable to create WWWAN port %s", port_conf->name);
+	}
+}
+
+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,
+};