karma.c revision dfe0d3ba20e860d0b9a16c4c6524180b8f93be05 
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
39extern int usb_stor_Bulk_transport(struct scsi_cmnd *, struct us_data *);
40
41struct 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 */
56static 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;
98err:
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 */
107int 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
130static void rio_karma_destructor(void *extra)
131{
132	struct karma_data *data = (struct karma_data *) extra;
133	kfree(data->recv);
134}
135
136int 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);
153out:
154	return ret;
155}
156