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
10 struct 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
rpmsg_wwan_ctrl_callback(struct rpmsg_device * rpdev,void * buf,int len,void * priv,u32 src)17 static 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(len, GFP_ATOMIC);
24 if (!skb)
25 return -ENOMEM;
26
27 skb_put_data(skb, buf, len);
28 wwan_port_rx(rpwwan->wwan_port, skb);
29 return 0;
30 }
31
rpmsg_wwan_ctrl_start(struct wwan_port * port)32 static 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 strncpy(chinfo.name, rpwwan->rpdev->id.name, RPMSG_NAME_SIZE);
41 rpwwan->ept = rpmsg_create_ept(rpwwan->rpdev, rpmsg_wwan_ctrl_callback,
42 rpwwan, chinfo);
43 if (!rpwwan->ept)
44 return -EREMOTEIO;
45
46 return 0;
47 }
48
rpmsg_wwan_ctrl_stop(struct wwan_port * port)49 static 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
rpmsg_wwan_ctrl_tx(struct wwan_port * port,struct sk_buff * skb)57 static 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(rpwwan->ept, skb->data, skb->len);
63 if (ret)
64 return ret;
65
66 consume_skb(skb);
67 return 0;
68 }
69
rpmsg_wwan_ctrl_tx_blocking(struct wwan_port * port,struct sk_buff * skb)70 static 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(rpwwan->ept, skb->data, skb->len);
76 if (ret)
77 return ret;
78
79 consume_skb(skb);
80 return 0;
81 }
82
rpmsg_wwan_ctrl_tx_poll(struct wwan_port * port,struct file * filp,poll_table * wait)83 static __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(rpwwan->ept, filp, wait);
89 }
90
91 static 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
rpmsg_wwan_find_parent(struct device * dev)99 static 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
rpmsg_wwan_ctrl_probe(struct rpmsg_device * rpdev)113 static 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(&rpdev->dev);
120 if (!parent)
121 return -ENODEV;
122
123 rpwwan = devm_kzalloc(&rpdev->dev, sizeof(*rpwwan), GFP_KERNEL);
124 if (!rpwwan)
125 return -ENOMEM;
126
127 rpwwan->rpdev = rpdev;
128 dev_set_drvdata(&rpdev->dev, rpwwan);
129
130 /* Register as a wwan port, id.driver_data contains wwan port type */
131 port = wwan_create_port(parent, rpdev->id.driver_data,
132 &rpmsg_wwan_pops, NULL, rpwwan);
133 if (IS_ERR(port))
134 return PTR_ERR(port);
135
136 rpwwan->wwan_port = port;
137
138 return 0;
139 };
140
rpmsg_wwan_ctrl_remove(struct rpmsg_device * rpdev)141 static void rpmsg_wwan_ctrl_remove(struct rpmsg_device *rpdev)
142 {
143 struct rpmsg_wwan_dev *rpwwan = dev_get_drvdata(&rpdev->dev);
144
145 wwan_remove_port(rpwwan->wwan_port);
146 }
147
148 static 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 };
155 MODULE_DEVICE_TABLE(rpmsg, rpmsg_wwan_ctrl_id_table);
156
157 static 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 };
163 module_rpmsg_driver(rpmsg_wwan_ctrl_driver);
164
165 MODULE_LICENSE("GPL v2");
166 MODULE_DESCRIPTION("RPMSG WWAN CTRL Driver");
167 MODULE_AUTHOR("Stephan Gerhold <stephan@gerhold.net>");
168