1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Driver for Option High Speed Mobile Devices.
4 *
5 *   (c) 2008 Dan Williams <dcbw@redhat.com>
6 *
7 * Inspiration taken from sierra_ms.c by Kevin Lloyd <klloyd@sierrawireless.com>
8 */
9
10#include <linux/usb.h>
11#include <linux/slab.h>
12#include <linux/module.h>
13
14#include "usb.h"
15#include "transport.h"
16#include "option_ms.h"
17#include "debug.h"
18
19#define ZCD_FORCE_MODEM			0x01
20#define ZCD_ALLOW_MS 			0x02
21
22static unsigned int option_zero_cd = ZCD_FORCE_MODEM;
23module_param(option_zero_cd, uint, S_IRUGO | S_IWUSR);
24MODULE_PARM_DESC(option_zero_cd, "ZeroCD mode (1=Force Modem (default),"
25		 " 2=Allow CD-Rom");
26
27#define RESPONSE_LEN 1024
28
29static int option_rezero(struct us_data *us)
30{
31	static const unsigned char rezero_msg[] = {
32	  0x55, 0x53, 0x42, 0x43, 0x78, 0x56, 0x34, 0x12,
33	  0x01, 0x00, 0x00, 0x00, 0x80, 0x00, 0x06, 0x01,
34	  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
35	  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
36	};
37	char *buffer;
38	int result;
39
40	usb_stor_dbg(us, "Option MS: %s\n", "DEVICE MODE SWITCH");
41
42	buffer = kzalloc(RESPONSE_LEN, GFP_KERNEL);
43	if (buffer == NULL)
44		return USB_STOR_TRANSPORT_ERROR;
45
46	memcpy(buffer, rezero_msg, sizeof(rezero_msg));
47	result = usb_stor_bulk_transfer_buf(us,
48			us->send_bulk_pipe,
49			buffer, sizeof(rezero_msg), NULL);
50	if (result != USB_STOR_XFER_GOOD) {
51		result = USB_STOR_XFER_ERROR;
52		goto out;
53	}
54
55	/*
56	 * Some of the devices need to be asked for a response, but we don't
57	 * care what that response is.
58	 */
59	usb_stor_bulk_transfer_buf(us,
60			us->recv_bulk_pipe,
61			buffer, RESPONSE_LEN, NULL);
62
63	/* Read the CSW */
64	usb_stor_bulk_transfer_buf(us,
65			us->recv_bulk_pipe,
66			buffer, 13, NULL);
67
68	result = USB_STOR_XFER_GOOD;
69
70out:
71	kfree(buffer);
72	return result;
73}
74
75static int option_inquiry(struct us_data *us)
76{
77	static const unsigned char inquiry_msg[] = {
78	  0x55, 0x53, 0x42, 0x43, 0x12, 0x34, 0x56, 0x78,
79	  0x24, 0x00, 0x00, 0x00, 0x80, 0x00, 0x06, 0x12,
80	  0x00, 0x00, 0x00, 0x24, 0x00, 0x00, 0x00, 0x00,
81	  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
82	};
83	char *buffer;
84	int result;
85
86	usb_stor_dbg(us, "Option MS: %s\n", "device inquiry for vendor name");
87
88	buffer = kzalloc(0x24, GFP_KERNEL);
89	if (buffer == NULL)
90		return USB_STOR_TRANSPORT_ERROR;
91
92	memcpy(buffer, inquiry_msg, sizeof(inquiry_msg));
93	result = usb_stor_bulk_transfer_buf(us,
94			us->send_bulk_pipe,
95			buffer, sizeof(inquiry_msg), NULL);
96	if (result != USB_STOR_XFER_GOOD) {
97		result = USB_STOR_XFER_ERROR;
98		goto out;
99	}
100
101	result = usb_stor_bulk_transfer_buf(us,
102			us->recv_bulk_pipe,
103			buffer, 0x24, NULL);
104	if (result != USB_STOR_XFER_GOOD) {
105		result = USB_STOR_XFER_ERROR;
106		goto out;
107	}
108
109	result = memcmp(buffer+8, "Option", 6);
110
111	if (result != 0)
112		result = memcmp(buffer+8, "ZCOPTION", 8);
113
114	/* Read the CSW */
115	usb_stor_bulk_transfer_buf(us,
116			us->recv_bulk_pipe,
117			buffer, 13, NULL);
118
119out:
120	kfree(buffer);
121	return result;
122}
123
124
125int option_ms_init(struct us_data *us)
126{
127	int result;
128
129	usb_stor_dbg(us, "Option MS: %s\n", "option_ms_init called");
130
131	/*
132	 * Additional test for vendor information via INQUIRY,
133	 * because some vendor/product IDs are ambiguous
134	 */
135	result = option_inquiry(us);
136	if (result != 0) {
137		usb_stor_dbg(us, "Option MS: %s\n",
138			     "vendor is not Option or not determinable, no action taken");
139		return 0;
140	} else
141		usb_stor_dbg(us, "Option MS: %s\n",
142			     "this is a genuine Option device, proceeding");
143
144	/* Force Modem mode */
145	if (option_zero_cd == ZCD_FORCE_MODEM) {
146		usb_stor_dbg(us, "Option MS: %s\n", "Forcing Modem Mode");
147		result = option_rezero(us);
148		if (result != USB_STOR_XFER_GOOD)
149			usb_stor_dbg(us, "Option MS: %s\n",
150				     "Failed to switch to modem mode");
151		return -EIO;
152	} else if (option_zero_cd == ZCD_ALLOW_MS) {
153		/* Allow Mass Storage mode (keep CD-Rom) */
154		usb_stor_dbg(us, "Option MS: %s\n",
155			     "Allowing Mass Storage Mode if device requests it");
156	}
157
158	return 0;
159}
160
161