1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* huawei_cdc_ncm.c - handles Huawei devices using the CDC NCM protocol as |
3 | * transport layer. |
4 | * Copyright (C) 2013 Enrico Mioso <mrkiko.rs@gmail.com> |
5 | * |
6 | * ABSTRACT: |
7 | * This driver handles devices resembling the CDC NCM standard, but |
8 | * encapsulating another protocol inside it. An example are some Huawei 3G |
9 | * devices, exposing an embedded AT channel where you can set up the NCM |
10 | * connection. |
11 | * This code has been heavily inspired by the cdc_mbim.c driver, which is |
12 | * Copyright (c) 2012 Smith Micro Software, Inc. |
13 | * Copyright (c) 2012 Bjørn Mork <bjorn@mork.no> |
14 | */ |
15 | |
16 | #include <linux/module.h> |
17 | #include <linux/netdevice.h> |
18 | #include <linux/ethtool.h> |
19 | #include <linux/if_vlan.h> |
20 | #include <linux/ip.h> |
21 | #include <linux/mii.h> |
22 | #include <linux/usb.h> |
23 | #include <linux/usb/cdc.h> |
24 | #include <linux/usb/usbnet.h> |
25 | #include <linux/usb/cdc-wdm.h> |
26 | #include <linux/usb/cdc_ncm.h> |
27 | |
28 | /* Driver data */ |
29 | struct huawei_cdc_ncm_state { |
30 | struct cdc_ncm_ctx *ctx; |
31 | atomic_t pmcount; |
32 | struct usb_driver *subdriver; |
33 | struct usb_interface *control; |
34 | struct usb_interface *data; |
35 | }; |
36 | |
37 | static int huawei_cdc_ncm_manage_power(struct usbnet *usbnet_dev, int on) |
38 | { |
39 | struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data; |
40 | int rv; |
41 | |
42 | if ((on && atomic_add_return(i: 1, v: &drvstate->pmcount) == 1) || |
43 | (!on && atomic_dec_and_test(v: &drvstate->pmcount))) { |
44 | rv = usb_autopm_get_interface(intf: usbnet_dev->intf); |
45 | usbnet_dev->intf->needs_remote_wakeup = on; |
46 | if (!rv) |
47 | usb_autopm_put_interface(intf: usbnet_dev->intf); |
48 | } |
49 | return 0; |
50 | } |
51 | |
52 | static int huawei_cdc_ncm_wdm_manage_power(struct usb_interface *intf, |
53 | int status) |
54 | { |
55 | struct usbnet *usbnet_dev = usb_get_intfdata(intf); |
56 | |
57 | /* can be called while disconnecting */ |
58 | if (!usbnet_dev) |
59 | return 0; |
60 | |
61 | return huawei_cdc_ncm_manage_power(usbnet_dev, on: status); |
62 | } |
63 | |
64 | |
65 | static int huawei_cdc_ncm_bind(struct usbnet *usbnet_dev, |
66 | struct usb_interface *intf) |
67 | { |
68 | struct cdc_ncm_ctx *ctx; |
69 | struct usb_driver *subdriver = ERR_PTR(error: -ENODEV); |
70 | int ret; |
71 | struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data; |
72 | int drvflags = 0; |
73 | |
74 | /* altsetting should always be 1 for NCM devices - so we hard-coded |
75 | * it here. Some huawei devices will need the NDP part of the NCM package to |
76 | * be at the end of the frame. |
77 | */ |
78 | drvflags |= CDC_NCM_FLAG_NDP_TO_END; |
79 | |
80 | /* For many Huawei devices the NTB32 mode is the default and the best mode |
81 | * they work with. Huawei E5785 and E5885 devices refuse to work in NTB16 mode at all. |
82 | */ |
83 | drvflags |= CDC_NCM_FLAG_PREFER_NTB32; |
84 | |
85 | ret = cdc_ncm_bind_common(dev: usbnet_dev, intf, data_altsetting: 1, drvflags); |
86 | if (ret) |
87 | goto err; |
88 | |
89 | ctx = drvstate->ctx; |
90 | |
91 | if (usbnet_dev->status) |
92 | /* The wMaxCommand buffer must be big enough to hold |
93 | * any message from the modem. Experience has shown |
94 | * that some replies are more than 256 bytes long |
95 | */ |
96 | subdriver = usb_cdc_wdm_register(intf: ctx->control, |
97 | ep: &usbnet_dev->status->desc, |
98 | bufsize: 1024, /* wMaxCommand */ |
99 | type: WWAN_PORT_AT, |
100 | manage_power: huawei_cdc_ncm_wdm_manage_power); |
101 | if (IS_ERR(ptr: subdriver)) { |
102 | ret = PTR_ERR(ptr: subdriver); |
103 | cdc_ncm_unbind(dev: usbnet_dev, intf); |
104 | goto err; |
105 | } |
106 | |
107 | /* Prevent usbnet from using the status descriptor */ |
108 | usbnet_dev->status = NULL; |
109 | |
110 | drvstate->subdriver = subdriver; |
111 | |
112 | err: |
113 | return ret; |
114 | } |
115 | |
116 | static void huawei_cdc_ncm_unbind(struct usbnet *usbnet_dev, |
117 | struct usb_interface *intf) |
118 | { |
119 | struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data; |
120 | struct cdc_ncm_ctx *ctx = drvstate->ctx; |
121 | |
122 | if (drvstate->subdriver && drvstate->subdriver->disconnect) |
123 | drvstate->subdriver->disconnect(ctx->control); |
124 | drvstate->subdriver = NULL; |
125 | |
126 | cdc_ncm_unbind(dev: usbnet_dev, intf); |
127 | } |
128 | |
129 | static int huawei_cdc_ncm_suspend(struct usb_interface *intf, |
130 | pm_message_t message) |
131 | { |
132 | int ret = 0; |
133 | struct usbnet *usbnet_dev = usb_get_intfdata(intf); |
134 | struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data; |
135 | struct cdc_ncm_ctx *ctx = drvstate->ctx; |
136 | |
137 | if (ctx == NULL) { |
138 | ret = -ENODEV; |
139 | goto error; |
140 | } |
141 | |
142 | ret = usbnet_suspend(intf, message); |
143 | if (ret < 0) |
144 | goto error; |
145 | |
146 | if (intf == ctx->control && |
147 | drvstate->subdriver && |
148 | drvstate->subdriver->suspend) |
149 | ret = drvstate->subdriver->suspend(intf, message); |
150 | if (ret < 0) |
151 | usbnet_resume(intf); |
152 | |
153 | error: |
154 | return ret; |
155 | } |
156 | |
157 | static int huawei_cdc_ncm_resume(struct usb_interface *intf) |
158 | { |
159 | int ret = 0; |
160 | struct usbnet *usbnet_dev = usb_get_intfdata(intf); |
161 | struct huawei_cdc_ncm_state *drvstate = (void *)&usbnet_dev->data; |
162 | bool callsub; |
163 | struct cdc_ncm_ctx *ctx = drvstate->ctx; |
164 | |
165 | /* should we call subdriver's resume function? */ |
166 | callsub = |
167 | (intf == ctx->control && |
168 | drvstate->subdriver && |
169 | drvstate->subdriver->resume); |
170 | |
171 | if (callsub) |
172 | ret = drvstate->subdriver->resume(intf); |
173 | if (ret < 0) |
174 | goto err; |
175 | ret = usbnet_resume(intf); |
176 | if (ret < 0 && callsub) |
177 | drvstate->subdriver->suspend(intf, PMSG_SUSPEND); |
178 | err: |
179 | return ret; |
180 | } |
181 | |
182 | static const struct driver_info huawei_cdc_ncm_info = { |
183 | .description = "Huawei CDC NCM device" , |
184 | .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN, |
185 | .bind = huawei_cdc_ncm_bind, |
186 | .unbind = huawei_cdc_ncm_unbind, |
187 | .manage_power = huawei_cdc_ncm_manage_power, |
188 | .rx_fixup = cdc_ncm_rx_fixup, |
189 | .tx_fixup = cdc_ncm_tx_fixup, |
190 | }; |
191 | |
192 | static const struct usb_device_id huawei_cdc_ncm_devs[] = { |
193 | /* Huawei NCM devices disguised as vendor specific */ |
194 | { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x16), |
195 | .driver_info = (unsigned long)&huawei_cdc_ncm_info, |
196 | }, |
197 | { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x46), |
198 | .driver_info = (unsigned long)&huawei_cdc_ncm_info, |
199 | }, |
200 | { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x02, 0x76), |
201 | .driver_info = (unsigned long)&huawei_cdc_ncm_info, |
202 | }, |
203 | { USB_VENDOR_AND_INTERFACE_INFO(0x12d1, 0xff, 0x03, 0x16), |
204 | .driver_info = (unsigned long)&huawei_cdc_ncm_info, |
205 | }, |
206 | |
207 | /* Terminating entry */ |
208 | { |
209 | }, |
210 | }; |
211 | MODULE_DEVICE_TABLE(usb, huawei_cdc_ncm_devs); |
212 | |
213 | static struct usb_driver huawei_cdc_ncm_driver = { |
214 | .name = "huawei_cdc_ncm" , |
215 | .id_table = huawei_cdc_ncm_devs, |
216 | .probe = usbnet_probe, |
217 | .disconnect = usbnet_disconnect, |
218 | .suspend = huawei_cdc_ncm_suspend, |
219 | .resume = huawei_cdc_ncm_resume, |
220 | .reset_resume = huawei_cdc_ncm_resume, |
221 | .supports_autosuspend = 1, |
222 | .disable_hub_initiated_lpm = 1, |
223 | }; |
224 | module_usb_driver(huawei_cdc_ncm_driver); |
225 | MODULE_AUTHOR("Enrico Mioso <mrkiko.rs@gmail.com>" ); |
226 | MODULE_DESCRIPTION("USB CDC NCM host driver with encapsulated protocol support" ); |
227 | MODULE_LICENSE("GPL" ); |
228 | |