Subject: [PATCH net-next v4 06/13] net: wwan: t7xx: Add AT and MBIM WWAN ports

From: Ricardo Martinez <[email-masked]>
Date: Thu, 13 Jan 2022 18:06:20 -0700

From: Chandrashekar Devegowda <[email-masked]>

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 <[email-masked]>
Co-developed-by: Ricardo Martinez <[email-masked]>
Signed-off-by: Ricardo Martinez <[email-masked]>
---
 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  | 225 ++++++++++++++++++++++++
 4 files changed, 251 insertions(+)
 create mode 100644 drivers/net/wwan/t7xx/t7xx_port_wwan.c

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 ec7bb31fa9ea..28fb4c24de57 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 a6c51e3bb373..4f2d4b2c2658 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..3398ef8dc21a
--- /dev/null
+++ b/drivers/net/wwan/t7xx/t7xx_port_wwan.c
@@ -0,0 +1,225 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021, MediaTek Inc.
+ * Copyright (c) 2021, Intel Corporation.
+ *
+ * Authors:
+ *  Amir Hanania <[email-masked]>
+ *  Chandrashekar Devegowda <[email-masked]>
+ *  Haijun Liu <[email-masked]>
+ *  Moises Veleta <[email-masked]>
+ *  Ricardo Martinez<[email-masked]>
+ *
+ * Contributors:
+ *  Andy Shevchenko <[email-masked]>
+ *  Chiranjeevi Rapolu <[email-masked]>
+ *  Eliot Lee <[email-masked]>
+ *  Sreehari Kancharla <[email-masked]>
+ */
+
+#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 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_len, alloc_size, txq_mtu = CLDMA_TXQ_MTU;
+	struct t7xx_port_static *port_static;
+	unsigned int len, i, packets;
+	struct t7xx_fsm_ctl *ctl;
+	enum md_state md_state;
+
+	len = skb->len;
+	if (!len)
+		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;
+	}
+
+	alloc_size = min_t(size_t, txq_mtu, len + CCCI_H_ELEN);
+	actual_len = alloc_size - CCCI_H_ELEN;
+	packets = DIV_ROUND_UP(len, txq_mtu - CCCI_H_ELEN);
+
+	for (i = 0; i < packets; i++) {
+		struct ccci_header *ccci_h;
+		struct sk_buff *skb_ccci;
+		int ret;
+
+		if (packets > 1 && packets == i + 1) {
+			actual_len = len % (txq_mtu - CCCI_H_ELEN);
+			alloc_size = actual_len + 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);
+		t7xx_ccci_header_init(ccci_h, 0, actual_len + CCCI_H_LEN, port_static->tx_ch, 0);
+		memcpy(skb_put(skb_ccci, actual_len), skb->data + i * (txq_mtu - CCCI_H_ELEN),
+		       actual_len);
+
+		t7xx_port_proxy_set_seq_num(port_private, ccci_h);
+
+		ret = t7xx_port_send_skb_to_md(port_private, skb_ccci, true);
+		if (ret) {
+			dev_err(port_private->dev, "Write error on %s port, %d\n",
+				port_static->name, ret);
+			dev_kfree_skb_any(skb_ccci);
+			return ret;
+		}
+
+		port_private->seq_nums[MTK_TX]++;
+	}
+
+	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)
+{
+	struct t7xx_port_static *port_static = port->port_static;
+
+	port->rx_length_th = RX_QUEUE_MAXLEN;
+	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,
+};
-- 
2.17.1