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 
9 #include <linux/module.h>
10 #include <scsi/scsi.h>
11 #include <scsi/scsi_cmnd.h>
12 #include <scsi/scsi_eh.h>
13 #include <linux/ata.h>
14 
15 #include "usb.h"
16 #include "protocol.h"
17 #include "scsiglue.h"
18 #include "debug.h"
19 
20 #define DRV_NAME "ums-cypress"
21 
22 MODULE_DESCRIPTION("SAT support for Cypress USB/ATA bridges with ATACB");
23 MODULE_AUTHOR("Matthieu Castet <castet.matthieu@free.fr>");
24 MODULE_LICENSE("GPL");
25 
26 /*
27  * The table of devices
28  */
29 #define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
30 		    vendorName, productName, useProtocol, useTransport, \
31 		    initFunction, flags) \
32 { USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
33   .driver_info = (flags) }
34 
35 static struct usb_device_id cypress_usb_ids[] = {
36 #	include "unusual_cypress.h"
37 	{ }		/* Terminating entry */
38 };
39 MODULE_DEVICE_TABLE(usb, cypress_usb_ids);
40 
41 #undef UNUSUAL_DEV
42 
43 /*
44  * The flags table
45  */
46 #define UNUSUAL_DEV(idVendor, idProduct, bcdDeviceMin, bcdDeviceMax, \
47 		    vendor_name, product_name, use_protocol, use_transport, \
48 		    init_function, Flags) \
49 { \
50 	.vendorName = vendor_name,	\
51 	.productName = product_name,	\
52 	.useProtocol = use_protocol,	\
53 	.useTransport = use_transport,	\
54 	.initFunction = init_function,	\
55 }
56 
57 static struct us_unusual_dev cypress_unusual_dev_list[] = {
58 #	include "unusual_cypress.h"
59 	{ }		/* Terminating entry */
60 };
61 
62 #undef UNUSUAL_DEV
63 
64 
65 /*
66  * ATACB is a protocol used on cypress usb<->ata bridge to
67  * send raw ATA command over mass storage
68  * There is a ATACB2 protocol that support LBA48 on newer chip.
69  * More info that be found on cy7c68310_8.pdf and cy7c68300c_8.pdf
70  * datasheet from cypress.com.
71  */
72 static void cypress_atacb_passthrough(struct scsi_cmnd *srb, struct us_data *us)
73 {
74 	unsigned char save_cmnd[MAX_COMMAND_SIZE];
75 
76 	if (likely(srb->cmnd[0] != ATA_16 && srb->cmnd[0] != ATA_12)) {
77 		usb_stor_transparent_scsi_command(srb, us);
78 		return;
79 	}
80 
81 	memcpy(save_cmnd, srb->cmnd, sizeof(save_cmnd));
82 	memset(srb->cmnd, 0, MAX_COMMAND_SIZE);
83 
84 	/* check if we support the command */
85 	if (save_cmnd[1] >> 5) /* MULTIPLE_COUNT */
86 		goto invalid_fld;
87 	/* check protocol */
88 	switch ((save_cmnd[1] >> 1) & 0xf) {
89 	case 3: /*no DATA */
90 	case 4: /* PIO in */
91 	case 5: /* PIO out */
92 		break;
93 	default:
94 		goto invalid_fld;
95 	}
96 
97 	/* first build the ATACB command */
98 	srb->cmd_len = 16;
99 
100 	srb->cmnd[0] = 0x24; /*
101 			      * bVSCBSignature : vendor-specific command
102 			      * this value can change, but most(all ?) manufacturers
103 			      * keep the cypress default : 0x24
104 			      */
105 	srb->cmnd[1] = 0x24; /* bVSCBSubCommand : 0x24 for ATACB */
106 
107 	srb->cmnd[3] = 0xff - 1; /*
108 				  * features, sector count, lba low, lba med
109 				  * lba high, device, command are valid
110 				  */
111 	srb->cmnd[4] = 1; /* TransferBlockCount : 512 */
112 
113 	if (save_cmnd[0] == ATA_16) {
114 		srb->cmnd[ 6] = save_cmnd[ 4]; /* features */
115 		srb->cmnd[ 7] = save_cmnd[ 6]; /* sector count */
116 		srb->cmnd[ 8] = save_cmnd[ 8]; /* lba low */
117 		srb->cmnd[ 9] = save_cmnd[10]; /* lba med */
118 		srb->cmnd[10] = save_cmnd[12]; /* lba high */
119 		srb->cmnd[11] = save_cmnd[13]; /* device */
120 		srb->cmnd[12] = save_cmnd[14]; /* command */
121 
122 		if (save_cmnd[1] & 0x01) {/* extended bit set for LBA48 */
123 			/* this could be supported by atacb2 */
124 			if (save_cmnd[3] || save_cmnd[5] || save_cmnd[7] || save_cmnd[9]
125 					|| save_cmnd[11])
126 				goto invalid_fld;
127 		}
128 	} else { /* ATA12 */
129 		srb->cmnd[ 6] = save_cmnd[3]; /* features */
130 		srb->cmnd[ 7] = save_cmnd[4]; /* sector count */
131 		srb->cmnd[ 8] = save_cmnd[5]; /* lba low */
132 		srb->cmnd[ 9] = save_cmnd[6]; /* lba med */
133 		srb->cmnd[10] = save_cmnd[7]; /* lba high */
134 		srb->cmnd[11] = save_cmnd[8]; /* device */
135 		srb->cmnd[12] = save_cmnd[9]; /* command */
136 
137 	}
138 	/* Filter SET_FEATURES - XFER MODE command */
139 	if ((srb->cmnd[12] == ATA_CMD_SET_FEATURES)
140 			&& (srb->cmnd[6] == SETFEATURES_XFER))
141 		goto invalid_fld;
142 
143 	if (srb->cmnd[12] == ATA_CMD_ID_ATA || srb->cmnd[12] == ATA_CMD_ID_ATAPI)
144 		srb->cmnd[2] |= (1<<7); /* set  IdentifyPacketDevice for these cmds */
145 
146 
147 	usb_stor_transparent_scsi_command(srb, us);
148 
149 	/* if the device doesn't support ATACB */
150 	if (srb->result == SAM_STAT_CHECK_CONDITION &&
151 			memcmp(srb->sense_buffer, usb_stor_sense_invalidCDB,
152 				sizeof(usb_stor_sense_invalidCDB)) == 0) {
153 		usb_stor_dbg(us, "cypress atacb not supported ???\n");
154 		goto end;
155 	}
156 
157 	/*
158 	 * if ck_cond flags is set, and there wasn't critical error,
159 	 * build the special sense
160 	 */
161 	if ((srb->result != (DID_ERROR << 16) &&
162 				srb->result != (DID_ABORT << 16)) &&
163 			save_cmnd[2] & 0x20) {
164 		struct scsi_eh_save ses;
165 		unsigned char regs[8];
166 		unsigned char *sb = srb->sense_buffer;
167 		unsigned char *desc = sb + 8;
168 		int tmp_result;
169 
170 		/* build the command for reading the ATA registers */
171 		scsi_eh_prep_cmnd(srb, &ses, NULL, 0, sizeof(regs));
172 
173 		/*
174 		 * we use the same command as before, but we set
175 		 * the read taskfile bit, for not executing atacb command,
176 		 * but reading register selected in srb->cmnd[4]
177 		 */
178 		srb->cmd_len = 16;
179 		srb->cmnd = ses.cmnd;
180 		srb->cmnd[2] = 1;
181 
182 		usb_stor_transparent_scsi_command(srb, us);
183 		memcpy(regs, srb->sense_buffer, sizeof(regs));
184 		tmp_result = srb->result;
185 		scsi_eh_restore_cmnd(srb, &ses);
186 		/* we fail to get registers, report invalid command */
187 		if (tmp_result != SAM_STAT_GOOD)
188 			goto invalid_fld;
189 
190 		/* build the sense */
191 		memset(sb, 0, SCSI_SENSE_BUFFERSIZE);
192 
193 		/* set sk, asc for a good command */
194 		sb[1] = RECOVERED_ERROR;
195 		sb[2] = 0; /* ATA PASS THROUGH INFORMATION AVAILABLE */
196 		sb[3] = 0x1D;
197 
198 		/*
199 		 * XXX we should generate sk, asc, ascq from status and error
200 		 * regs
201 		 * (see 11.1 Error translation ATA device error to SCSI error
202 		 * map, and ata_to_sense_error from libata.)
203 		 */
204 
205 		/* Sense data is current and format is descriptor. */
206 		sb[0] = 0x72;
207 		desc[0] = 0x09; /* ATA_RETURN_DESCRIPTOR */
208 
209 		/* set length of additional sense data */
210 		sb[7] = 14;
211 		desc[1] = 12;
212 
213 		/* Copy registers into sense buffer. */
214 		desc[ 2] = 0x00;
215 		desc[ 3] = regs[1];  /* features */
216 		desc[ 5] = regs[2];  /* sector count */
217 		desc[ 7] = regs[3];  /* lba low */
218 		desc[ 9] = regs[4];  /* lba med */
219 		desc[11] = regs[5];  /* lba high */
220 		desc[12] = regs[6];  /* device */
221 		desc[13] = regs[7];  /* command */
222 
223 		srb->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
224 	}
225 	goto end;
226 invalid_fld:
227 	srb->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
228 
229 	memcpy(srb->sense_buffer,
230 			usb_stor_sense_invalidCDB,
231 			sizeof(usb_stor_sense_invalidCDB));
232 end:
233 	memcpy(srb->cmnd, save_cmnd, sizeof(save_cmnd));
234 	if (srb->cmnd[0] == ATA_12)
235 		srb->cmd_len = 12;
236 }
237 
238 static struct scsi_host_template cypress_host_template;
239 
240 static int cypress_probe(struct usb_interface *intf,
241 			 const struct usb_device_id *id)
242 {
243 	struct us_data *us;
244 	int result;
245 	struct usb_device *device;
246 
247 	result = usb_stor_probe1(&us, intf, id,
248 			(id - cypress_usb_ids) + cypress_unusual_dev_list,
249 			&cypress_host_template);
250 	if (result)
251 		return result;
252 
253 	/*
254 	 * Among CY7C68300 chips, the A revision does not support Cypress ATACB
255 	 * Filter out this revision from EEPROM default descriptor values
256 	 */
257 	device = interface_to_usbdev(intf);
258 	if (device->descriptor.iManufacturer != 0x38 ||
259 	    device->descriptor.iProduct != 0x4e ||
260 	    device->descriptor.iSerialNumber != 0x64) {
261 		us->protocol_name = "Transparent SCSI with Cypress ATACB";
262 		us->proto_handler = cypress_atacb_passthrough;
263 	} else {
264 		us->protocol_name = "Transparent SCSI";
265 		us->proto_handler = usb_stor_transparent_scsi_command;
266 	}
267 
268 	result = usb_stor_probe2(us);
269 	return result;
270 }
271 
272 static struct usb_driver cypress_driver = {
273 	.name =		DRV_NAME,
274 	.probe =	cypress_probe,
275 	.disconnect =	usb_stor_disconnect,
276 	.suspend =	usb_stor_suspend,
277 	.resume =	usb_stor_resume,
278 	.reset_resume =	usb_stor_reset_resume,
279 	.pre_reset =	usb_stor_pre_reset,
280 	.post_reset =	usb_stor_post_reset,
281 	.id_table =	cypress_usb_ids,
282 	.soft_unbind =	1,
283 	.no_dynamic_id = 1,
284 };
285 
286 module_usb_stor_driver(cypress_driver, cypress_host_template, DRV_NAME);
287