1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Support for emulating SAT (ata pass through) on devices based
4  *       on the Cypress USB/ATA bridge supporting ATACB.
5  *
6  * Copyright (c) 2008 Matthieu Castet (castet.matthieu@free.fr)
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License as published by the
10  * Free Software Foundation; either version 2, or (at your option) any
11  * later version.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License along
19  * with this program; if not, write to the Free Software Foundation, Inc.,
20  * 675 Mass Ave, Cambridge, MA 02139, USA.
21  */
22 
23 #include <linux/module.h>
24 #include <scsi/scsi.h>
25 #include <scsi/scsi_cmnd.h>
26 #include <scsi/scsi_eh.h>
27 #include <linux/ata.h>
28 
29 #include "usb.h"
30 #include "protocol.h"
31 #include "scsiglue.h"
32 #include "debug.h"
33 
34 #define DRV_NAME "ums-cypress"
35 
36 MODULE_DESCRIPTION("SAT support for Cypress USB/ATA bridges with ATACB");
37 MODULE_AUTHOR("Matthieu Castet <castet.matthieu@free.fr>");
38 MODULE_LICENSE("GPL");
39 
40 /*
41  * The table of devices
42  */
43 #define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
44 		    vendorName, productName, useProtocol, useTransport, \
45 		    initFunction, flags) \
46 { USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
47   .driver_info = (flags) }
48 
49 static struct usb_device_id cypress_usb_ids[] = {
50 #	include "unusual_cypress.h"
51 	{ }		/* Terminating entry */
52 };
53 MODULE_DEVICE_TABLE(usb, cypress_usb_ids);
54 
55 #undef UNUSUAL_DEV
56 
57 /*
58  * The flags table
59  */
60 #define UNUSUAL_DEV(idVendor, idProduct, bcdDeviceMin, bcdDeviceMax, \
61 		    vendor_name, product_name, use_protocol, use_transport, \
62 		    init_function, Flags) \
63 { \
64 	.vendorName = vendor_name,	\
65 	.productName = product_name,	\
66 	.useProtocol = use_protocol,	\
67 	.useTransport = use_transport,	\
68 	.initFunction = init_function,	\
69 }
70 
71 static struct us_unusual_dev cypress_unusual_dev_list[] = {
72 #	include "unusual_cypress.h"
73 	{ }		/* Terminating entry */
74 };
75 
76 #undef UNUSUAL_DEV
77 
78 
79 /*
80  * ATACB is a protocol used on cypress usb<->ata bridge to
81  * send raw ATA command over mass storage
82  * There is a ATACB2 protocol that support LBA48 on newer chip.
83  * More info that be found on cy7c68310_8.pdf and cy7c68300c_8.pdf
84  * datasheet from cypress.com.
85  */
86 static void cypress_atacb_passthrough(struct scsi_cmnd *srb, struct us_data *us)
87 {
88 	unsigned char save_cmnd[MAX_COMMAND_SIZE];
89 
90 	if (likely(srb->cmnd[0] != ATA_16 && srb->cmnd[0] != ATA_12)) {
91 		usb_stor_transparent_scsi_command(srb, us);
92 		return;
93 	}
94 
95 	memcpy(save_cmnd, srb->cmnd, sizeof(save_cmnd));
96 	memset(srb->cmnd, 0, MAX_COMMAND_SIZE);
97 
98 	/* check if we support the command */
99 	if (save_cmnd[1] >> 5) /* MULTIPLE_COUNT */
100 		goto invalid_fld;
101 	/* check protocol */
102 	switch ((save_cmnd[1] >> 1) & 0xf) {
103 	case 3: /*no DATA */
104 	case 4: /* PIO in */
105 	case 5: /* PIO out */
106 		break;
107 	default:
108 		goto invalid_fld;
109 	}
110 
111 	/* first build the ATACB command */
112 	srb->cmd_len = 16;
113 
114 	srb->cmnd[0] = 0x24; /*
115 			      * bVSCBSignature : vendor-specific command
116 			      * this value can change, but most(all ?) manufacturers
117 			      * keep the cypress default : 0x24
118 			      */
119 	srb->cmnd[1] = 0x24; /* bVSCBSubCommand : 0x24 for ATACB */
120 
121 	srb->cmnd[3] = 0xff - 1; /*
122 				  * features, sector count, lba low, lba med
123 				  * lba high, device, command are valid
124 				  */
125 	srb->cmnd[4] = 1; /* TransferBlockCount : 512 */
126 
127 	if (save_cmnd[0] == ATA_16) {
128 		srb->cmnd[ 6] = save_cmnd[ 4]; /* features */
129 		srb->cmnd[ 7] = save_cmnd[ 6]; /* sector count */
130 		srb->cmnd[ 8] = save_cmnd[ 8]; /* lba low */
131 		srb->cmnd[ 9] = save_cmnd[10]; /* lba med */
132 		srb->cmnd[10] = save_cmnd[12]; /* lba high */
133 		srb->cmnd[11] = save_cmnd[13]; /* device */
134 		srb->cmnd[12] = save_cmnd[14]; /* command */
135 
136 		if (save_cmnd[1] & 0x01) {/* extended bit set for LBA48 */
137 			/* this could be supported by atacb2 */
138 			if (save_cmnd[3] || save_cmnd[5] || save_cmnd[7] || save_cmnd[9]
139 					|| save_cmnd[11])
140 				goto invalid_fld;
141 		}
142 	} else { /* ATA12 */
143 		srb->cmnd[ 6] = save_cmnd[3]; /* features */
144 		srb->cmnd[ 7] = save_cmnd[4]; /* sector count */
145 		srb->cmnd[ 8] = save_cmnd[5]; /* lba low */
146 		srb->cmnd[ 9] = save_cmnd[6]; /* lba med */
147 		srb->cmnd[10] = save_cmnd[7]; /* lba high */
148 		srb->cmnd[11] = save_cmnd[8]; /* device */
149 		srb->cmnd[12] = save_cmnd[9]; /* command */
150 
151 	}
152 	/* Filter SET_FEATURES - XFER MODE command */
153 	if ((srb->cmnd[12] == ATA_CMD_SET_FEATURES)
154 			&& (srb->cmnd[6] == SETFEATURES_XFER))
155 		goto invalid_fld;
156 
157 	if (srb->cmnd[12] == ATA_CMD_ID_ATA || srb->cmnd[12] == ATA_CMD_ID_ATAPI)
158 		srb->cmnd[2] |= (1<<7); /* set  IdentifyPacketDevice for these cmds */
159 
160 
161 	usb_stor_transparent_scsi_command(srb, us);
162 
163 	/* if the device doesn't support ATACB */
164 	if (srb->result == SAM_STAT_CHECK_CONDITION &&
165 			memcmp(srb->sense_buffer, usb_stor_sense_invalidCDB,
166 				sizeof(usb_stor_sense_invalidCDB)) == 0) {
167 		usb_stor_dbg(us, "cypress atacb not supported ???\n");
168 		goto end;
169 	}
170 
171 	/*
172 	 * if ck_cond flags is set, and there wasn't critical error,
173 	 * build the special sense
174 	 */
175 	if ((srb->result != (DID_ERROR << 16) &&
176 				srb->result != (DID_ABORT << 16)) &&
177 			save_cmnd[2] & 0x20) {
178 		struct scsi_eh_save ses;
179 		unsigned char regs[8];
180 		unsigned char *sb = srb->sense_buffer;
181 		unsigned char *desc = sb + 8;
182 		int tmp_result;
183 
184 		/* build the command for reading the ATA registers */
185 		scsi_eh_prep_cmnd(srb, &ses, NULL, 0, sizeof(regs));
186 
187 		/*
188 		 * we use the same command as before, but we set
189 		 * the read taskfile bit, for not executing atacb command,
190 		 * but reading register selected in srb->cmnd[4]
191 		 */
192 		srb->cmd_len = 16;
193 		srb->cmnd = ses.cmnd;
194 		srb->cmnd[2] = 1;
195 
196 		usb_stor_transparent_scsi_command(srb, us);
197 		memcpy(regs, srb->sense_buffer, sizeof(regs));
198 		tmp_result = srb->result;
199 		scsi_eh_restore_cmnd(srb, &ses);
200 		/* we fail to get registers, report invalid command */
201 		if (tmp_result != SAM_STAT_GOOD)
202 			goto invalid_fld;
203 
204 		/* build the sense */
205 		memset(sb, 0, SCSI_SENSE_BUFFERSIZE);
206 
207 		/* set sk, asc for a good command */
208 		sb[1] = RECOVERED_ERROR;
209 		sb[2] = 0; /* ATA PASS THROUGH INFORMATION AVAILABLE */
210 		sb[3] = 0x1D;
211 
212 		/*
213 		 * XXX we should generate sk, asc, ascq from status and error
214 		 * regs
215 		 * (see 11.1 Error translation ATA device error to SCSI error
216 		 * map, and ata_to_sense_error from libata.)
217 		 */
218 
219 		/* Sense data is current and format is descriptor. */
220 		sb[0] = 0x72;
221 		desc[0] = 0x09; /* ATA_RETURN_DESCRIPTOR */
222 
223 		/* set length of additional sense data */
224 		sb[7] = 14;
225 		desc[1] = 12;
226 
227 		/* Copy registers into sense buffer. */
228 		desc[ 2] = 0x00;
229 		desc[ 3] = regs[1];  /* features */
230 		desc[ 5] = regs[2];  /* sector count */
231 		desc[ 7] = regs[3];  /* lba low */
232 		desc[ 9] = regs[4];  /* lba med */
233 		desc[11] = regs[5];  /* lba high */
234 		desc[12] = regs[6];  /* device */
235 		desc[13] = regs[7];  /* command */
236 
237 		srb->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
238 	}
239 	goto end;
240 invalid_fld:
241 	srb->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
242 
243 	memcpy(srb->sense_buffer,
244 			usb_stor_sense_invalidCDB,
245 			sizeof(usb_stor_sense_invalidCDB));
246 end:
247 	memcpy(srb->cmnd, save_cmnd, sizeof(save_cmnd));
248 	if (srb->cmnd[0] == ATA_12)
249 		srb->cmd_len = 12;
250 }
251 
252 static struct scsi_host_template cypress_host_template;
253 
254 static int cypress_probe(struct usb_interface *intf,
255 			 const struct usb_device_id *id)
256 {
257 	struct us_data *us;
258 	int result;
259 	struct usb_device *device;
260 
261 	result = usb_stor_probe1(&us, intf, id,
262 			(id - cypress_usb_ids) + cypress_unusual_dev_list,
263 			&cypress_host_template);
264 	if (result)
265 		return result;
266 
267 	/*
268 	 * Among CY7C68300 chips, the A revision does not support Cypress ATACB
269 	 * Filter out this revision from EEPROM default descriptor values
270 	 */
271 	device = interface_to_usbdev(intf);
272 	if (device->descriptor.iManufacturer != 0x38 ||
273 	    device->descriptor.iProduct != 0x4e ||
274 	    device->descriptor.iSerialNumber != 0x64) {
275 		us->protocol_name = "Transparent SCSI with Cypress ATACB";
276 		us->proto_handler = cypress_atacb_passthrough;
277 	} else {
278 		us->protocol_name = "Transparent SCSI";
279 		us->proto_handler = usb_stor_transparent_scsi_command;
280 	}
281 
282 	result = usb_stor_probe2(us);
283 	return result;
284 }
285 
286 static struct usb_driver cypress_driver = {
287 	.name =		DRV_NAME,
288 	.probe =	cypress_probe,
289 	.disconnect =	usb_stor_disconnect,
290 	.suspend =	usb_stor_suspend,
291 	.resume =	usb_stor_resume,
292 	.reset_resume =	usb_stor_reset_resume,
293 	.pre_reset =	usb_stor_pre_reset,
294 	.post_reset =	usb_stor_post_reset,
295 	.id_table =	cypress_usb_ids,
296 	.soft_unbind =	1,
297 	.no_dynamic_id = 1,
298 };
299 
300 module_usb_stor_driver(cypress_driver, cypress_host_template, DRV_NAME);
301