1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2021, Stephan Gerhold <stephan@gerhold.net> */
3 #include <linux/kernel.h>
4 #include <linux/module.h>
5 #include <linux/platform_device.h>
6 #include <linux/rpmsg.h>
7 #include <linux/wwan.h>
8
9 struct rpmsg_wwan_dev {
10 /* Lower level is a rpmsg dev, upper level is a wwan port */
11 struct rpmsg_device *rpdev;
12 struct wwan_port *wwan_port;
13 struct rpmsg_endpoint *ept;
14 };
15
rpmsg_wwan_ctrl_callback(struct rpmsg_device * rpdev,void * buf,int len,void * priv,u32 src)16 static int rpmsg_wwan_ctrl_callback(struct rpmsg_device *rpdev,
17 void *buf, int len, void *priv, u32 src)
18 {
19 struct rpmsg_wwan_dev *rpwwan = priv;
20 struct sk_buff *skb;
21
22 skb = alloc_skb(len, GFP_ATOMIC);
23 if (!skb)
24 return -ENOMEM;
25
26 skb_put_data(skb, buf, len);
27 wwan_port_rx(rpwwan->wwan_port, skb);
28 return 0;
29 }
30
rpmsg_wwan_ctrl_start(struct wwan_port * port)31 static int rpmsg_wwan_ctrl_start(struct wwan_port *port)
32 {
33 struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port);
34 struct rpmsg_channel_info chinfo = {
35 .src = rpwwan->rpdev->src,
36 .dst = RPMSG_ADDR_ANY,
37 };
38
39 strscpy(chinfo.name, rpwwan->rpdev->id.name, sizeof(chinfo.name));
40 rpwwan->ept = rpmsg_create_ept(rpwwan->rpdev, rpmsg_wwan_ctrl_callback,
41 rpwwan, chinfo);
42 if (!rpwwan->ept)
43 return -EREMOTEIO;
44
45 return 0;
46 }
47
rpmsg_wwan_ctrl_stop(struct wwan_port * port)48 static void rpmsg_wwan_ctrl_stop(struct wwan_port *port)
49 {
50 struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port);
51
52 rpmsg_destroy_ept(rpwwan->ept);
53 rpwwan->ept = NULL;
54 }
55
rpmsg_wwan_ctrl_tx(struct wwan_port * port,struct sk_buff * skb)56 static int rpmsg_wwan_ctrl_tx(struct wwan_port *port, struct sk_buff *skb)
57 {
58 struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port);
59 int ret;
60
61 ret = rpmsg_trysend(rpwwan->ept, skb->data, skb->len);
62 if (ret)
63 return ret;
64
65 consume_skb(skb);
66 return 0;
67 }
68
rpmsg_wwan_ctrl_tx_blocking(struct wwan_port * port,struct sk_buff * skb)69 static int rpmsg_wwan_ctrl_tx_blocking(struct wwan_port *port, struct sk_buff *skb)
70 {
71 struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port);
72 int ret;
73
74 ret = rpmsg_send(rpwwan->ept, skb->data, skb->len);
75 if (ret)
76 return ret;
77
78 consume_skb(skb);
79 return 0;
80 }
81
rpmsg_wwan_ctrl_tx_poll(struct wwan_port * port,struct file * filp,poll_table * wait)82 static __poll_t rpmsg_wwan_ctrl_tx_poll(struct wwan_port *port,
83 struct file *filp, poll_table *wait)
84 {
85 struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port);
86
87 return rpmsg_poll(rpwwan->ept, filp, wait);
88 }
89
90 static const struct wwan_port_ops rpmsg_wwan_pops = {
91 .start = rpmsg_wwan_ctrl_start,
92 .stop = rpmsg_wwan_ctrl_stop,
93 .tx = rpmsg_wwan_ctrl_tx,
94 .tx_blocking = rpmsg_wwan_ctrl_tx_blocking,
95 .tx_poll = rpmsg_wwan_ctrl_tx_poll,
96 };
97
rpmsg_wwan_find_parent(struct device * dev)98 static struct device *rpmsg_wwan_find_parent(struct device *dev)
99 {
100 /* Select first platform device as parent for the WWAN ports.
101 * On Qualcomm platforms this is usually the platform device that
102 * represents the modem remote processor. This might need to be
103 * adjusted when adding device IDs for other platforms.
104 */
105 for (dev = dev->parent; dev; dev = dev->parent) {
106 if (dev_is_platform(dev))
107 return dev;
108 }
109 return NULL;
110 }
111
rpmsg_wwan_ctrl_probe(struct rpmsg_device * rpdev)112 static int rpmsg_wwan_ctrl_probe(struct rpmsg_device *rpdev)
113 {
114 struct rpmsg_wwan_dev *rpwwan;
115 struct wwan_port *port;
116 struct device *parent;
117
118 parent = rpmsg_wwan_find_parent(&rpdev->dev);
119 if (!parent)
120 return -ENODEV;
121
122 rpwwan = devm_kzalloc(&rpdev->dev, sizeof(*rpwwan), GFP_KERNEL);
123 if (!rpwwan)
124 return -ENOMEM;
125
126 rpwwan->rpdev = rpdev;
127 dev_set_drvdata(&rpdev->dev, rpwwan);
128
129 /* Register as a wwan port, id.driver_data contains wwan port type */
130 port = wwan_create_port(parent, rpdev->id.driver_data,
131 &rpmsg_wwan_pops, NULL, rpwwan);
132 if (IS_ERR(port))
133 return PTR_ERR(port);
134
135 rpwwan->wwan_port = port;
136
137 return 0;
138 };
139
rpmsg_wwan_ctrl_remove(struct rpmsg_device * rpdev)140 static void rpmsg_wwan_ctrl_remove(struct rpmsg_device *rpdev)
141 {
142 struct rpmsg_wwan_dev *rpwwan = dev_get_drvdata(&rpdev->dev);
143
144 wwan_remove_port(rpwwan->wwan_port);
145 }
146
147 static const struct rpmsg_device_id rpmsg_wwan_ctrl_id_table[] = {
148 /* RPMSG channels for Qualcomm SoCs with integrated modem */
149 { .name = "DATA5_CNTL", .driver_data = WWAN_PORT_QMI },
150 { .name = "DATA4", .driver_data = WWAN_PORT_AT },
151 { .name = "DATA1", .driver_data = WWAN_PORT_AT },
152 {},
153 };
154 MODULE_DEVICE_TABLE(rpmsg, rpmsg_wwan_ctrl_id_table);
155
156 static struct rpmsg_driver rpmsg_wwan_ctrl_driver = {
157 .drv.name = "rpmsg_wwan_ctrl",
158 .id_table = rpmsg_wwan_ctrl_id_table,
159 .probe = rpmsg_wwan_ctrl_probe,
160 .remove = rpmsg_wwan_ctrl_remove,
161 };
162 module_rpmsg_driver(rpmsg_wwan_ctrl_driver);
163
164 MODULE_LICENSE("GPL v2");
165 MODULE_DESCRIPTION("RPMSG WWAN CTRL Driver");
166 MODULE_AUTHOR("Stephan Gerhold <stephan@gerhold.net>");
167