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/mod_devicetable.h>
5#include <linux/module.h>
6#include <linux/platform_device.h>
7#include <linux/rpmsg.h>
8#include <linux/wwan.h>
9
10struct rpmsg_wwan_dev {
11 /* Lower level is a rpmsg dev, upper level is a wwan port */
12 struct rpmsg_device *rpdev;
13 struct wwan_port *wwan_port;
14 struct rpmsg_endpoint *ept;
15};
16
17static int rpmsg_wwan_ctrl_callback(struct rpmsg_device *rpdev,
18 void *buf, int len, void *priv, u32 src)
19{
20 struct rpmsg_wwan_dev *rpwwan = priv;
21 struct sk_buff *skb;
22
23 skb = alloc_skb(size: len, GFP_ATOMIC);
24 if (!skb)
25 return -ENOMEM;
26
27 skb_put_data(skb, data: buf, len);
28 wwan_port_rx(port: rpwwan->wwan_port, skb);
29 return 0;
30}
31
32static int rpmsg_wwan_ctrl_start(struct wwan_port *port)
33{
34 struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port);
35 struct rpmsg_channel_info chinfo = {
36 .src = rpwwan->rpdev->src,
37 .dst = RPMSG_ADDR_ANY,
38 };
39
40 strscpy(chinfo.name, rpwwan->rpdev->id.name, sizeof(chinfo.name));
41 rpwwan->ept = rpmsg_create_ept(rpwwan->rpdev, cb: rpmsg_wwan_ctrl_callback,
42 priv: rpwwan, chinfo);
43 if (!rpwwan->ept)
44 return -EREMOTEIO;
45
46 return 0;
47}
48
49static void rpmsg_wwan_ctrl_stop(struct wwan_port *port)
50{
51 struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port);
52
53 rpmsg_destroy_ept(rpwwan->ept);
54 rpwwan->ept = NULL;
55}
56
57static int rpmsg_wwan_ctrl_tx(struct wwan_port *port, struct sk_buff *skb)
58{
59 struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port);
60 int ret;
61
62 ret = rpmsg_trysend(ept: rpwwan->ept, data: skb->data, len: skb->len);
63 if (ret)
64 return ret;
65
66 consume_skb(skb);
67 return 0;
68}
69
70static int rpmsg_wwan_ctrl_tx_blocking(struct wwan_port *port, struct sk_buff *skb)
71{
72 struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port);
73 int ret;
74
75 ret = rpmsg_send(ept: rpwwan->ept, data: skb->data, len: skb->len);
76 if (ret)
77 return ret;
78
79 consume_skb(skb);
80 return 0;
81}
82
83static __poll_t rpmsg_wwan_ctrl_tx_poll(struct wwan_port *port,
84 struct file *filp, poll_table *wait)
85{
86 struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port);
87
88 return rpmsg_poll(ept: rpwwan->ept, filp, wait);
89}
90
91static const struct wwan_port_ops rpmsg_wwan_pops = {
92 .start = rpmsg_wwan_ctrl_start,
93 .stop = rpmsg_wwan_ctrl_stop,
94 .tx = rpmsg_wwan_ctrl_tx,
95 .tx_blocking = rpmsg_wwan_ctrl_tx_blocking,
96 .tx_poll = rpmsg_wwan_ctrl_tx_poll,
97};
98
99static struct device *rpmsg_wwan_find_parent(struct device *dev)
100{
101 /* Select first platform device as parent for the WWAN ports.
102 * On Qualcomm platforms this is usually the platform device that
103 * represents the modem remote processor. This might need to be
104 * adjusted when adding device IDs for other platforms.
105 */
106 for (dev = dev->parent; dev; dev = dev->parent) {
107 if (dev_is_platform(dev))
108 return dev;
109 }
110 return NULL;
111}
112
113static int rpmsg_wwan_ctrl_probe(struct rpmsg_device *rpdev)
114{
115 struct rpmsg_wwan_dev *rpwwan;
116 struct wwan_port *port;
117 struct device *parent;
118
119 parent = rpmsg_wwan_find_parent(dev: &rpdev->dev);
120 if (!parent)
121 return -ENODEV;
122
123 rpwwan = devm_kzalloc(dev: &rpdev->dev, size: sizeof(*rpwwan), GFP_KERNEL);
124 if (!rpwwan)
125 return -ENOMEM;
126
127 rpwwan->rpdev = rpdev;
128 dev_set_drvdata(dev: &rpdev->dev, data: rpwwan);
129
130 /* Register as a wwan port, id.driver_data contains wwan port type */
131 port = wwan_create_port(parent, type: rpdev->id.driver_data,
132 ops: &rpmsg_wwan_pops, NULL, drvdata: rpwwan);
133 if (IS_ERR(ptr: port))
134 return PTR_ERR(ptr: port);
135
136 rpwwan->wwan_port = port;
137
138 return 0;
139};
140
141static void rpmsg_wwan_ctrl_remove(struct rpmsg_device *rpdev)
142{
143 struct rpmsg_wwan_dev *rpwwan = dev_get_drvdata(dev: &rpdev->dev);
144
145 wwan_remove_port(port: rpwwan->wwan_port);
146}
147
148static const struct rpmsg_device_id rpmsg_wwan_ctrl_id_table[] = {
149 /* RPMSG channels for Qualcomm SoCs with integrated modem */
150 { .name = "DATA5_CNTL", .driver_data = WWAN_PORT_QMI },
151 { .name = "DATA4", .driver_data = WWAN_PORT_AT },
152 { .name = "DATA1", .driver_data = WWAN_PORT_AT },
153 {},
154};
155MODULE_DEVICE_TABLE(rpmsg, rpmsg_wwan_ctrl_id_table);
156
157static struct rpmsg_driver rpmsg_wwan_ctrl_driver = {
158 .drv.name = "rpmsg_wwan_ctrl",
159 .id_table = rpmsg_wwan_ctrl_id_table,
160 .probe = rpmsg_wwan_ctrl_probe,
161 .remove = rpmsg_wwan_ctrl_remove,
162};
163module_rpmsg_driver(rpmsg_wwan_ctrl_driver);
164
165MODULE_LICENSE("GPL v2");
166MODULE_DESCRIPTION("RPMSG WWAN CTRL Driver");
167MODULE_AUTHOR("Stephan Gerhold <stephan@gerhold.net>");
168

source code of linux/drivers/net/wwan/rpmsg_wwan_ctrl.c