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 #define DRV_NAME "ums-cypress"
34 
35 MODULE_DESCRIPTION("SAT support for Cypress USB/ATA bridges with ATACB");
36 MODULE_AUTHOR("Matthieu Castet <castet.matthieu@free.fr>");
37 MODULE_LICENSE("GPL");
38 
39 /*
40  * The table of devices
41  */
42 #define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
43 		    vendorName, productName, useProtocol, useTransport, \
44 		    initFunction, flags) \
45 { USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
46   .driver_info = (flags) }
47 
48 static struct usb_device_id cypress_usb_ids[] = {
49 #	include "unusual_cypress.h"
50 	{ }		/* Terminating entry */
51 };
52 MODULE_DEVICE_TABLE(usb, cypress_usb_ids);
53 
54 #undef UNUSUAL_DEV
55 
56 /*
57  * The flags table
58  */
59 #define UNUSUAL_DEV(idVendor, idProduct, bcdDeviceMin, bcdDeviceMax, \
60 		    vendor_name, product_name, use_protocol, use_transport, \
61 		    init_function, Flags) \
62 { \
63 	.vendorName = vendor_name,	\
64 	.productName = product_name,	\
65 	.useProtocol = use_protocol,	\
66 	.useTransport = use_transport,	\
67 	.initFunction = init_function,	\
68 }
69 
70 static struct us_unusual_dev cypress_unusual_dev_list[] = {
71 #	include "unusual_cypress.h"
72 	{ }		/* Terminating entry */
73 };
74 
75 #undef UNUSUAL_DEV
76 
77 
78 /*
79  * ATACB is a protocol used on cypress usb<->ata bridge to
80  * send raw ATA command over mass storage
81  * There is a ATACB2 protocol that support LBA48 on newer chip.
82  * More info that be found on cy7c68310_8.pdf and cy7c68300c_8.pdf
83  * datasheet from cypress.com.
84  */
85 static void cypress_atacb_passthrough(struct scsi_cmnd *srb, struct us_data *us)
86 {
87 	unsigned char save_cmnd[MAX_COMMAND_SIZE];
88 
89 	if (likely(srb->cmnd[0] != ATA_16 && srb->cmnd[0] != ATA_12)) {
90 		usb_stor_transparent_scsi_command(srb, us);
91 		return;
92 	}
93 
94 	memcpy(save_cmnd, srb->cmnd, sizeof(save_cmnd));
95 	memset(srb->cmnd, 0, MAX_COMMAND_SIZE);
96 
97 	/* check if we support the command */
98 	if (save_cmnd[1] >> 5) /* MULTIPLE_COUNT */
99 		goto invalid_fld;
100 	/* check protocol */
101 	switch ((save_cmnd[1] >> 1) & 0xf) {
102 	case 3: /*no DATA */
103 	case 4: /* PIO in */
104 	case 5: /* PIO out */
105 		break;
106 	default:
107 		goto invalid_fld;
108 	}
109 
110 	/* first build the ATACB command */
111 	srb->cmd_len = 16;
112 
113 	srb->cmnd[0] = 0x24; /*
114 			      * bVSCBSignature : vendor-specific command
115 			      * this value can change, but most(all ?) manufacturers
116 			      * keep the cypress default : 0x24
117 			      */
118 	srb->cmnd[1] = 0x24; /* bVSCBSubCommand : 0x24 for ATACB */
119 
120 	srb->cmnd[3] = 0xff - 1; /*
121 				  * features, sector count, lba low, lba med
122 				  * lba high, device, command are valid
123 				  */
124 	srb->cmnd[4] = 1; /* TransferBlockCount : 512 */
125 
126 	if (save_cmnd[0] == ATA_16) {
127 		srb->cmnd[ 6] = save_cmnd[ 4]; /* features */
128 		srb->cmnd[ 7] = save_cmnd[ 6]; /* sector count */
129 		srb->cmnd[ 8] = save_cmnd[ 8]; /* lba low */
130 		srb->cmnd[ 9] = save_cmnd[10]; /* lba med */
131 		srb->cmnd[10] = save_cmnd[12]; /* lba high */
132 		srb->cmnd[11] = save_cmnd[13]; /* device */
133 		srb->cmnd[12] = save_cmnd[14]; /* command */
134 
135 		if (save_cmnd[1] & 0x01) {/* extended bit set for LBA48 */
136 			/* this could be supported by atacb2 */
137 			if (save_cmnd[3] || save_cmnd[5] || save_cmnd[7] || save_cmnd[9]
138 					|| save_cmnd[11])
139 				goto invalid_fld;
140 		}
141 	} else { /* ATA12 */
142 		srb->cmnd[ 6] = save_cmnd[3]; /* features */
143 		srb->cmnd[ 7] = save_cmnd[4]; /* sector count */
144 		srb->cmnd[ 8] = save_cmnd[5]; /* lba low */
145 		srb->cmnd[ 9] = save_cmnd[6]; /* lba med */
146 		srb->cmnd[10] = save_cmnd[7]; /* lba high */
147 		srb->cmnd[11] = save_cmnd[8]; /* device */
148 		srb->cmnd[12] = save_cmnd[9]; /* command */
149 
150 	}
151 	/* Filter SET_FEATURES - XFER MODE command */
152 	if ((srb->cmnd[12] == ATA_CMD_SET_FEATURES)
153 			&& (srb->cmnd[6] == SETFEATURES_XFER))
154 		goto invalid_fld;
155 
156 	if (srb->cmnd[12] == ATA_CMD_ID_ATA || srb->cmnd[12] == ATA_CMD_ID_ATAPI)
157 		srb->cmnd[2] |= (1<<7); /* set  IdentifyPacketDevice for these cmds */
158 
159 
160 	usb_stor_transparent_scsi_command(srb, us);
161 
162 	/* if the device doesn't support ATACB */
163 	if (srb->result == SAM_STAT_CHECK_CONDITION &&
164 			memcmp(srb->sense_buffer, usb_stor_sense_invalidCDB,
165 				sizeof(usb_stor_sense_invalidCDB)) == 0) {
166 		usb_stor_dbg(us, "cypress atacb not supported ???\n");
167 		goto end;
168 	}
169 
170 	/*
171 	 * if ck_cond flags is set, and there wasn't critical error,
172 	 * build the special sense
173 	 */
174 	if ((srb->result != (DID_ERROR << 16) &&
175 				srb->result != (DID_ABORT << 16)) &&
176 			save_cmnd[2] & 0x20) {
177 		struct scsi_eh_save ses;
178 		unsigned char regs[8];
179 		unsigned char *sb = srb->sense_buffer;
180 		unsigned char *desc = sb + 8;
181 		int tmp_result;
182 
183 		/* build the command for reading the ATA registers */
184 		scsi_eh_prep_cmnd(srb, &ses, NULL, 0, sizeof(regs));
185 
186 		/*
187 		 * we use the same command as before, but we set
188 		 * the read taskfile bit, for not executing atacb command,
189 		 * but reading register selected in srb->cmnd[4]
190 		 */
191 		srb->cmd_len = 16;
192 		srb->cmnd = ses.cmnd;
193 		srb->cmnd[2] = 1;
194 
195 		usb_stor_transparent_scsi_command(srb, us);
196 		memcpy(regs, srb->sense_buffer, sizeof(regs));
197 		tmp_result = srb->result;
198 		scsi_eh_restore_cmnd(srb, &ses);
199 		/* we fail to get registers, report invalid command */
200 		if (tmp_result != SAM_STAT_GOOD)
201 			goto invalid_fld;
202 
203 		/* build the sense */
204 		memset(sb, 0, SCSI_SENSE_BUFFERSIZE);
205 
206 		/* set sk, asc for a good command */
207 		sb[1] = RECOVERED_ERROR;
208 		sb[2] = 0; /* ATA PASS THROUGH INFORMATION AVAILABLE */
209 		sb[3] = 0x1D;
210 
211 		/*
212 		 * XXX we should generate sk, asc, ascq from status and error
213 		 * regs
214 		 * (see 11.1 Error translation ATA device error to SCSI error
215 		 * map, and ata_to_sense_error from libata.)
216 		 */
217 
218 		/* Sense data is current and format is descriptor. */
219 		sb[0] = 0x72;
220 		desc[0] = 0x09; /* ATA_RETURN_DESCRIPTOR */
221 
222 		/* set length of additional sense data */
223 		sb[7] = 14;
224 		desc[1] = 12;
225 
226 		/* Copy registers into sense buffer. */
227 		desc[ 2] = 0x00;
228 		desc[ 3] = regs[1];  /* features */
229 		desc[ 5] = regs[2];  /* sector count */
230 		desc[ 7] = regs[3];  /* lba low */
231 		desc[ 9] = regs[4];  /* lba med */
232 		desc[11] = regs[5];  /* lba high */
233 		desc[12] = regs[6];  /* device */
234 		desc[13] = regs[7];  /* command */
235 
236 		srb->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
237 	}
238 	goto end;
239 invalid_fld:
240 	srb->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
241 
242 	memcpy(srb->sense_buffer,
243 			usb_stor_sense_invalidCDB,
244 			sizeof(usb_stor_sense_invalidCDB));
245 end:
246 	memcpy(srb->cmnd, save_cmnd, sizeof(save_cmnd));
247 	if (srb->cmnd[0] == ATA_12)
248 		srb->cmd_len = 12;
249 }
250 
251 static struct scsi_host_template cypress_host_template;
252 
253 static int cypress_probe(struct usb_interface *intf,
254 			 const struct usb_device_id *id)
255 {
256 	struct us_data *us;
257 	int result;
258 	struct usb_device *device;
259 
260 	result = usb_stor_probe1(&us, intf, id,
261 			(id - cypress_usb_ids) + cypress_unusual_dev_list,
262 			&cypress_host_template);
263 	if (result)
264 		return result;
265 
266 	/*
267 	 * Among CY7C68300 chips, the A revision does not support Cypress ATACB
268 	 * Filter out this revision from EEPROM default descriptor values
269 	 */
270 	device = interface_to_usbdev(intf);
271 	if (device->descriptor.iManufacturer != 0x38 ||
272 	    device->descriptor.iProduct != 0x4e ||
273 	    device->descriptor.iSerialNumber != 0x64) {
274 		us->protocol_name = "Transparent SCSI with Cypress ATACB";
275 		us->proto_handler = cypress_atacb_passthrough;
276 	} else {
277 		us->protocol_name = "Transparent SCSI";
278 		us->proto_handler = usb_stor_transparent_scsi_command;
279 	}
280 
281 	result = usb_stor_probe2(us);
282 	return result;
283 }
284 
285 static struct usb_driver cypress_driver = {
286 	.name =		DRV_NAME,
287 	.probe =	cypress_probe,
288 	.disconnect =	usb_stor_disconnect,
289 	.suspend =	usb_stor_suspend,
290 	.resume =	usb_stor_resume,
291 	.reset_resume =	usb_stor_reset_resume,
292 	.pre_reset =	usb_stor_pre_reset,
293 	.post_reset =	usb_stor_post_reset,
294 	.id_table =	cypress_usb_ids,
295 	.soft_unbind =	1,
296 	.no_dynamic_id = 1,
297 };
298 
299 module_usb_stor_driver(cypress_driver, cypress_host_template, DRV_NAME);
300