1/*
2 * Support for emulating SAT (ata pass through) on devices based
3 *       on the Cypress USB/ATA bridge supporting ATACB.
4 *
5 * Copyright (c) 2008 Matthieu Castet (castet.matthieu@free.fr)
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2, or (at your option) any
10 * later version.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22#include <linux/module.h>
23#include <scsi/scsi.h>
24#include <scsi/scsi_cmnd.h>
25#include <scsi/scsi_eh.h>
26#include <linux/ata.h>
27
28#include "usb.h"
29#include "protocol.h"
30#include "scsiglue.h"
31#include "debug.h"
32
33MODULE_DESCRIPTION("SAT support for Cypress USB/ATA bridges with ATACB");
34MODULE_AUTHOR("Matthieu Castet <castet.matthieu@free.fr>");
35MODULE_LICENSE("GPL");
36
37/*
38 * The table of devices
39 */
40#define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
41		    vendorName, productName, useProtocol, useTransport, \
42		    initFunction, flags) \
43{ USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
44  .driver_info = (flags) }
45
46static struct usb_device_id cypress_usb_ids[] = {
47#	include "unusual_cypress.h"
48	{ }		/* Terminating entry */
49};
50MODULE_DEVICE_TABLE(usb, cypress_usb_ids);
51
52#undef UNUSUAL_DEV
53
54/*
55 * The flags table
56 */
57#define UNUSUAL_DEV(idVendor, idProduct, bcdDeviceMin, bcdDeviceMax, \
58		    vendor_name, product_name, use_protocol, use_transport, \
59		    init_function, Flags) \
60{ \
61	.vendorName = vendor_name,	\
62	.productName = product_name,	\
63	.useProtocol = use_protocol,	\
64	.useTransport = use_transport,	\
65	.initFunction = init_function,	\
66}
67
68static struct us_unusual_dev cypress_unusual_dev_list[] = {
69#	include "unusual_cypress.h"
70	{ }		/* Terminating entry */
71};
72
73#undef UNUSUAL_DEV
74
75
76/*
77 * ATACB is a protocol used on cypress usb<->ata bridge to
78 * send raw ATA command over mass storage
79 * There is a ATACB2 protocol that support LBA48 on newer chip.
80 * More info that be found on cy7c68310_8.pdf and cy7c68300c_8.pdf
81 * datasheet from cypress.com.
82 */
83static void cypress_atacb_passthrough(struct scsi_cmnd *srb, struct us_data *us)
84{
85	unsigned char save_cmnd[MAX_COMMAND_SIZE];
86
87	if (likely(srb->cmnd[0] != ATA_16 && srb->cmnd[0] != ATA_12)) {
88		usb_stor_transparent_scsi_command(srb, us);
89		return;
90	}
91
92	memcpy(save_cmnd, srb->cmnd, sizeof(save_cmnd));
93	memset(srb->cmnd, 0, MAX_COMMAND_SIZE);
94
95	/* check if we support the command */
96	if (save_cmnd[1] >> 5) /* MULTIPLE_COUNT */
97		goto invalid_fld;
98	/* check protocol */
99	switch ((save_cmnd[1] >> 1) & 0xf) {
100	case 3: /*no DATA */
101	case 4: /* PIO in */
102	case 5: /* PIO out */
103		break;
104	default:
105		goto invalid_fld;
106	}
107
108	/* first build the ATACB command */
109	srb->cmd_len = 16;
110
111	srb->cmnd[0] = 0x24; /* bVSCBSignature : vendor-specific command
112	                        this value can change, but most(all ?) manufacturers
113							keep the cypress default : 0x24 */
114	srb->cmnd[1] = 0x24; /* bVSCBSubCommand : 0x24 for ATACB */
115
116	srb->cmnd[3] = 0xff - 1; /* features, sector count, lba low, lba med
117								lba high, device, command are valid */
118	srb->cmnd[4] = 1; /* TransferBlockCount : 512 */
119
120	if (save_cmnd[0] == ATA_16) {
121		srb->cmnd[ 6] = save_cmnd[ 4]; /* features */
122		srb->cmnd[ 7] = save_cmnd[ 6]; /* sector count */
123		srb->cmnd[ 8] = save_cmnd[ 8]; /* lba low */
124		srb->cmnd[ 9] = save_cmnd[10]; /* lba med */
125		srb->cmnd[10] = save_cmnd[12]; /* lba high */
126		srb->cmnd[11] = save_cmnd[13]; /* device */
127		srb->cmnd[12] = save_cmnd[14]; /* command */
128
129		if (save_cmnd[1] & 0x01) {/* extended bit set for LBA48 */
130			/* this could be supported by atacb2 */
131			if (save_cmnd[3] || save_cmnd[5] || save_cmnd[7] || save_cmnd[9]
132					|| save_cmnd[11])
133				goto invalid_fld;
134		}
135	} else { /* ATA12 */
136		srb->cmnd[ 6] = save_cmnd[3]; /* features */
137		srb->cmnd[ 7] = save_cmnd[4]; /* sector count */
138		srb->cmnd[ 8] = save_cmnd[5]; /* lba low */
139		srb->cmnd[ 9] = save_cmnd[6]; /* lba med */
140		srb->cmnd[10] = save_cmnd[7]; /* lba high */
141		srb->cmnd[11] = save_cmnd[8]; /* device */
142		srb->cmnd[12] = save_cmnd[9]; /* command */
143
144	}
145	/* Filter SET_FEATURES - XFER MODE command */
146	if ((srb->cmnd[12] == ATA_CMD_SET_FEATURES)
147			&& (srb->cmnd[6] == SETFEATURES_XFER))
148		goto invalid_fld;
149
150	if (srb->cmnd[12] == ATA_CMD_ID_ATA || srb->cmnd[12] == ATA_CMD_ID_ATAPI)
151		srb->cmnd[2] |= (1<<7); /* set  IdentifyPacketDevice for these cmds */
152
153
154	usb_stor_transparent_scsi_command(srb, us);
155
156	/* if the device doesn't support ATACB
157	 */
158	if (srb->result == SAM_STAT_CHECK_CONDITION &&
159			memcmp(srb->sense_buffer, usb_stor_sense_invalidCDB,
160				sizeof(usb_stor_sense_invalidCDB)) == 0) {
161		usb_stor_dbg(us, "cypress atacb not supported ???\n");
162		goto end;
163	}
164
165	/* if ck_cond flags is set, and there wasn't critical error,
166	 * build the special sense
167	 */
168	if ((srb->result != (DID_ERROR << 16) &&
169				srb->result != (DID_ABORT << 16)) &&
170			save_cmnd[2] & 0x20) {
171		struct scsi_eh_save ses;
172		unsigned char regs[8];
173		unsigned char *sb = srb->sense_buffer;
174		unsigned char *desc = sb + 8;
175		int tmp_result;
176
177		/* build the command for
178		 * reading the ATA registers */
179		scsi_eh_prep_cmnd(srb, &ses, NULL, 0, sizeof(regs));
180
181		/* we use the same command as before, but we set
182		 * the read taskfile bit, for not executing atacb command,
183		 * but reading register selected in srb->cmnd[4]
184		 */
185		srb->cmd_len = 16;
186		srb->cmnd = ses.cmnd;
187		srb->cmnd[2] = 1;
188
189		usb_stor_transparent_scsi_command(srb, us);
190		memcpy(regs, srb->sense_buffer, sizeof(regs));
191		tmp_result = srb->result;
192		scsi_eh_restore_cmnd(srb, &ses);
193		/* we fail to get registers, report invalid command */
194		if (tmp_result != SAM_STAT_GOOD)
195			goto invalid_fld;
196
197		/* build the sense */
198		memset(sb, 0, SCSI_SENSE_BUFFERSIZE);
199
200		/* set sk, asc for a good command */
201		sb[1] = RECOVERED_ERROR;
202		sb[2] = 0; /* ATA PASS THROUGH INFORMATION AVAILABLE */
203		sb[3] = 0x1D;
204
205		/* XXX we should generate sk, asc, ascq from status and error
206		 * regs
207		 * (see 11.1 Error translation ATA device error to SCSI error
208		 *  map, and ata_to_sense_error from libata.)
209		 */
210
211		/* Sense data is current and format is descriptor. */
212		sb[0] = 0x72;
213		desc[0] = 0x09; /* ATA_RETURN_DESCRIPTOR */
214
215		/* set length of additional sense data */
216		sb[7] = 14;
217		desc[1] = 12;
218
219		/* Copy registers into sense buffer. */
220		desc[ 2] = 0x00;
221		desc[ 3] = regs[1];  /* features */
222		desc[ 5] = regs[2];  /* sector count */
223		desc[ 7] = regs[3];  /* lba low */
224		desc[ 9] = regs[4];  /* lba med */
225		desc[11] = regs[5];  /* lba high */
226		desc[12] = regs[6];  /* device */
227		desc[13] = regs[7];  /* command */
228
229		srb->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
230	}
231	goto end;
232invalid_fld:
233	srb->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
234
235	memcpy(srb->sense_buffer,
236			usb_stor_sense_invalidCDB,
237			sizeof(usb_stor_sense_invalidCDB));
238end:
239	memcpy(srb->cmnd, save_cmnd, sizeof(save_cmnd));
240	if (srb->cmnd[0] == ATA_12)
241		srb->cmd_len = 12;
242}
243
244
245static int cypress_probe(struct usb_interface *intf,
246			 const struct usb_device_id *id)
247{
248	struct us_data *us;
249	int result;
250	struct usb_device *device;
251
252	result = usb_stor_probe1(&us, intf, id,
253			(id - cypress_usb_ids) + cypress_unusual_dev_list);
254	if (result)
255		return result;
256
257	/* Among CY7C68300 chips, the A revision does not support Cypress ATACB
258	 * Filter out this revision from EEPROM default descriptor values
259	 */
260	device = interface_to_usbdev(intf);
261	if (device->descriptor.iManufacturer != 0x38 ||
262	    device->descriptor.iProduct != 0x4e ||
263	    device->descriptor.iSerialNumber != 0x64) {
264		us->protocol_name = "Transparent SCSI with Cypress ATACB";
265		us->proto_handler = cypress_atacb_passthrough;
266	} else {
267		us->protocol_name = "Transparent SCSI";
268		us->proto_handler = usb_stor_transparent_scsi_command;
269	}
270
271	result = usb_stor_probe2(us);
272	return result;
273}
274
275static struct usb_driver cypress_driver = {
276	.name =		"ums-cypress",
277	.probe =	cypress_probe,
278	.disconnect =	usb_stor_disconnect,
279	.suspend =	usb_stor_suspend,
280	.resume =	usb_stor_resume,
281	.reset_resume =	usb_stor_reset_resume,
282	.pre_reset =	usb_stor_pre_reset,
283	.post_reset =	usb_stor_post_reset,
284	.id_table =	cypress_usb_ids,
285	.soft_unbind =	1,
286	.no_dynamic_id = 1,
287};
288
289module_usb_driver(cypress_driver);
290