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 
33 MODULE_DESCRIPTION("SAT support for Cypress USB/ATA bridges with ATACB");
34 MODULE_AUTHOR("Matthieu Castet <castet.matthieu@free.fr>");
35 MODULE_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 
46 static struct usb_device_id cypress_usb_ids[] = {
47 #	include "unusual_cypress.h"
48 	{ }		/* Terminating entry */
49 };
50 MODULE_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 
68 static 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  */
83 static 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;
232 invalid_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));
238 end:
239 	memcpy(srb->cmnd, save_cmnd, sizeof(save_cmnd));
240 	if (srb->cmnd[0] == ATA_12)
241 		srb->cmd_len = 12;
242 }
243 
244 
245 static 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 
275 static 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 
289 module_usb_driver(cypress_driver);
290