xref: /linux/drivers/usb/storage/option_ms.c (revision 664b0bae0b87f69bc9deb098f5e0158b9cf18e04)
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 
22 static unsigned int option_zero_cd = ZCD_FORCE_MODEM;
23 module_param(option_zero_cd, uint, S_IRUGO | S_IWUSR);
24 MODULE_PARM_DESC(option_zero_cd, "ZeroCD mode (1=Force Modem (default),"
25 		 " 2=Allow CD-Rom");
26 
27 #define RESPONSE_LEN 1024
28 
option_rezero(struct us_data * us)29 static 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 
70 out:
71 	kfree(buffer);
72 	return result;
73 }
74 
option_inquiry(struct us_data * us)75 static 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 
119 out:
120 	kfree(buffer);
121 	return result;
122 }
123 
124 
option_ms_init(struct us_data * us)125 int 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