xref: /linux/drivers/usb/storage/option_ms.c (revision 38502ef49f96f7fe25fcb3aaa904a570df955c2c)
1 /*
2  * Driver for Option High Speed Mobile Devices.
3  *
4  *   (c) 2008 Dan Williams <dcbw@redhat.com>
5  *
6  * Inspiration taken from sierra_ms.c by Kevin Lloyd <klloyd@sierrawireless.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License along
19  * with this program; if not, write to the Free Software Foundation, Inc.,
20  * 675 Mass Ave, Cambridge, MA 02139, USA.
21  */
22 
23 #include <linux/usb.h>
24 #include <linux/slab.h>
25 #include <linux/module.h>
26 
27 #include "usb.h"
28 #include "transport.h"
29 #include "option_ms.h"
30 #include "debug.h"
31 
32 #define ZCD_FORCE_MODEM			0x01
33 #define ZCD_ALLOW_MS 			0x02
34 
35 static unsigned int option_zero_cd = ZCD_FORCE_MODEM;
36 module_param(option_zero_cd, uint, S_IRUGO | S_IWUSR);
37 MODULE_PARM_DESC(option_zero_cd, "ZeroCD mode (1=Force Modem (default),"
38 		 " 2=Allow CD-Rom");
39 
40 #define RESPONSE_LEN 1024
41 
42 static int option_rezero(struct us_data *us)
43 {
44 	static const unsigned char rezero_msg[] = {
45 	  0x55, 0x53, 0x42, 0x43, 0x78, 0x56, 0x34, 0x12,
46 	  0x01, 0x00, 0x00, 0x00, 0x80, 0x00, 0x06, 0x01,
47 	  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
48 	  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
49 	};
50 	char *buffer;
51 	int result;
52 
53 	usb_stor_dbg(us, "Option MS: %s\n", "DEVICE MODE SWITCH");
54 
55 	buffer = kzalloc(RESPONSE_LEN, GFP_KERNEL);
56 	if (buffer == NULL)
57 		return USB_STOR_TRANSPORT_ERROR;
58 
59 	memcpy(buffer, rezero_msg, sizeof(rezero_msg));
60 	result = usb_stor_bulk_transfer_buf(us,
61 			us->send_bulk_pipe,
62 			buffer, sizeof(rezero_msg), NULL);
63 	if (result != USB_STOR_XFER_GOOD) {
64 		result = USB_STOR_XFER_ERROR;
65 		goto out;
66 	}
67 
68 	/*
69 	 * Some of the devices need to be asked for a response, but we don't
70 	 * care what that response is.
71 	 */
72 	usb_stor_bulk_transfer_buf(us,
73 			us->recv_bulk_pipe,
74 			buffer, RESPONSE_LEN, NULL);
75 
76 	/* Read the CSW */
77 	usb_stor_bulk_transfer_buf(us,
78 			us->recv_bulk_pipe,
79 			buffer, 13, NULL);
80 
81 	result = USB_STOR_XFER_GOOD;
82 
83 out:
84 	kfree(buffer);
85 	return result;
86 }
87 
88 static int option_inquiry(struct us_data *us)
89 {
90 	static const unsigned char inquiry_msg[] = {
91 	  0x55, 0x53, 0x42, 0x43, 0x12, 0x34, 0x56, 0x78,
92 	  0x24, 0x00, 0x00, 0x00, 0x80, 0x00, 0x06, 0x12,
93 	  0x00, 0x00, 0x00, 0x24, 0x00, 0x00, 0x00, 0x00,
94 	  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
95 	};
96 	char *buffer;
97 	int result;
98 
99 	usb_stor_dbg(us, "Option MS: %s\n", "device inquiry for vendor name");
100 
101 	buffer = kzalloc(0x24, GFP_KERNEL);
102 	if (buffer == NULL)
103 		return USB_STOR_TRANSPORT_ERROR;
104 
105 	memcpy(buffer, inquiry_msg, sizeof(inquiry_msg));
106 	result = usb_stor_bulk_transfer_buf(us,
107 			us->send_bulk_pipe,
108 			buffer, sizeof(inquiry_msg), NULL);
109 	if (result != USB_STOR_XFER_GOOD) {
110 		result = USB_STOR_XFER_ERROR;
111 		goto out;
112 	}
113 
114 	result = usb_stor_bulk_transfer_buf(us,
115 			us->recv_bulk_pipe,
116 			buffer, 0x24, NULL);
117 	if (result != USB_STOR_XFER_GOOD) {
118 		result = USB_STOR_XFER_ERROR;
119 		goto out;
120 	}
121 
122 	result = memcmp(buffer+8, "Option", 6);
123 
124 	if (result != 0)
125 		result = memcmp(buffer+8, "ZCOPTION", 8);
126 
127 	/* Read the CSW */
128 	usb_stor_bulk_transfer_buf(us,
129 			us->recv_bulk_pipe,
130 			buffer, 13, NULL);
131 
132 out:
133 	kfree(buffer);
134 	return result;
135 }
136 
137 
138 int option_ms_init(struct us_data *us)
139 {
140 	int result;
141 
142 	usb_stor_dbg(us, "Option MS: %s\n", "option_ms_init called");
143 
144 	/*
145 	 * Additional test for vendor information via INQUIRY,
146 	 * because some vendor/product IDs are ambiguous
147 	 */
148 	result = option_inquiry(us);
149 	if (result != 0) {
150 		usb_stor_dbg(us, "Option MS: %s\n",
151 			     "vendor is not Option or not determinable, no action taken");
152 		return 0;
153 	} else
154 		usb_stor_dbg(us, "Option MS: %s\n",
155 			     "this is a genuine Option device, proceeding");
156 
157 	/* Force Modem mode */
158 	if (option_zero_cd == ZCD_FORCE_MODEM) {
159 		usb_stor_dbg(us, "Option MS: %s\n", "Forcing Modem Mode");
160 		result = option_rezero(us);
161 		if (result != USB_STOR_XFER_GOOD)
162 			usb_stor_dbg(us, "Option MS: %s\n",
163 				     "Failed to switch to modem mode");
164 		return -EIO;
165 	} else if (option_zero_cd == ZCD_ALLOW_MS) {
166 		/* Allow Mass Storage mode (keep CD-Rom) */
167 		usb_stor_dbg(us, "Option MS: %s\n",
168 			     "Allowing Mass Storage Mode if device requests it");
169 	}
170 
171 	return 0;
172 }
173 
174