xref: /openbmc/linux/drivers/usb/storage/karma.c (revision 643d1f7f)
1 /* Driver for Rio Karma
2  *
3  *   (c) 2006 Bob Copeland <me@bobcopeland.com>
4  *   (c) 2006 Keith Bennett <keith@mcs.st-and.ac.uk>
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License as published by the
8  * Free Software Foundation; either version 2, or (at your option) any
9  * later version.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License along
17  * with this program; if not, write to the Free Software Foundation, Inc.,
18  * 675 Mass Ave, Cambridge, MA 02139, USA.
19  */
20 
21 #include <scsi/scsi.h>
22 #include <scsi/scsi_cmnd.h>
23 #include <scsi/scsi_device.h>
24 
25 #include "usb.h"
26 #include "transport.h"
27 #include "debug.h"
28 #include "karma.h"
29 
30 #define RIO_PREFIX "RIOP\x00"
31 #define RIO_PREFIX_LEN 5
32 #define RIO_SEND_LEN 40
33 #define RIO_RECV_LEN 0x200
34 
35 #define RIO_ENTER_STORAGE 0x1
36 #define RIO_LEAVE_STORAGE 0x2
37 #define RIO_RESET 0xC
38 
39 extern int usb_stor_Bulk_transport(struct scsi_cmnd *, struct us_data *);
40 
41 struct karma_data {
42 	int in_storage;
43 	char *recv;
44 };
45 
46 /*
47  * Send commands to Rio Karma.
48  *
49  * For each command we send 40 bytes starting 'RIOP\0' followed by
50  * the command number and a sequence number, which the device will ack
51  * with a 512-byte packet with the high four bits set and everything
52  * else null.  Then we send 'RIOP\x80' followed by a zero and the
53  * sequence number, until byte 5 in the response repeats the sequence
54  * number.
55  */
56 static int rio_karma_send_command(char cmd, struct us_data *us)
57 {
58 	int result, partial;
59 	unsigned long timeout;
60 	static unsigned char seq = 1;
61 	struct karma_data *data = (struct karma_data *) us->extra;
62 
63 	US_DEBUGP("karma: sending command %04x\n", cmd);
64 	memset(us->iobuf, 0, RIO_SEND_LEN);
65 	memcpy(us->iobuf, RIO_PREFIX, RIO_PREFIX_LEN);
66 	us->iobuf[5] = cmd;
67 	us->iobuf[6] = seq;
68 
69 	timeout = jiffies + msecs_to_jiffies(6000);
70 	for (;;) {
71 		result = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
72 			us->iobuf, RIO_SEND_LEN, &partial);
73 		if (result != USB_STOR_XFER_GOOD)
74 			goto err;
75 
76 		result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
77 			data->recv, RIO_RECV_LEN, &partial);
78 		if (result != USB_STOR_XFER_GOOD)
79 			goto err;
80 
81 		if (data->recv[5] == seq)
82 			break;
83 
84 		if (time_after(jiffies, timeout))
85 			goto err;
86 
87 		us->iobuf[4] = 0x80;
88 		us->iobuf[5] = 0;
89 		msleep(50);
90 	}
91 
92 	seq++;
93 	if (seq == 0)
94 		seq = 1;
95 
96 	US_DEBUGP("karma: sent command %04x\n", cmd);
97 	return 0;
98 err:
99 	US_DEBUGP("karma: command %04x failed\n", cmd);
100 	return USB_STOR_TRANSPORT_FAILED;
101 }
102 
103 /*
104  * Trap START_STOP and READ_10 to leave/re-enter storage mode.
105  * Everything else is propagated to the normal bulk layer.
106  */
107 int rio_karma_transport(struct scsi_cmnd *srb, struct us_data *us)
108 {
109 	int ret;
110 	struct karma_data *data = (struct karma_data *) us->extra;
111 
112 	if (srb->cmnd[0] == READ_10 && !data->in_storage) {
113 		ret = rio_karma_send_command(RIO_ENTER_STORAGE, us);
114 		if (ret)
115 			return ret;
116 
117 		data->in_storage = 1;
118 		return usb_stor_Bulk_transport(srb, us);
119 	} else if (srb->cmnd[0] == START_STOP) {
120 		ret = rio_karma_send_command(RIO_LEAVE_STORAGE, us);
121 		if (ret)
122 			return ret;
123 
124 		data->in_storage = 0;
125 		return rio_karma_send_command(RIO_RESET, us);
126 	}
127 	return usb_stor_Bulk_transport(srb, us);
128 }
129 
130 static void rio_karma_destructor(void *extra)
131 {
132 	struct karma_data *data = (struct karma_data *) extra;
133 	kfree(data->recv);
134 }
135 
136 int rio_karma_init(struct us_data *us)
137 {
138 	int ret = 0;
139 	struct karma_data *data = kzalloc(sizeof(struct karma_data), GFP_NOIO);
140 	if (!data)
141 		goto out;
142 
143 	data->recv = kmalloc(RIO_RECV_LEN, GFP_NOIO);
144 	if (!data->recv) {
145 		kfree(data);
146 		goto out;
147 	}
148 
149 	us->extra = data;
150 	us->extra_destructor = rio_karma_destructor;
151 	ret = rio_karma_send_command(RIO_ENTER_STORAGE, us);
152 	data->in_storage = (ret == 0);
153 out:
154 	return ret;
155 }
156