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 MODULE_IMPORT_NS(USB_STORAGE);
26 
27 /*
28  * The table of devices
29  */
30 #define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
31 		    vendorName, productName, useProtocol, useTransport, \
32 		    initFunction, flags) \
33 { USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
34   .driver_info = (flags) }
35 
36 static struct usb_device_id cypress_usb_ids[] = {
37 #	include "unusual_cypress.h"
38 	{ }		/* Terminating entry */
39 };
40 MODULE_DEVICE_TABLE(usb, cypress_usb_ids);
41 
42 #undef UNUSUAL_DEV
43 
44 /*
45  * The flags table
46  */
47 #define UNUSUAL_DEV(idVendor, idProduct, bcdDeviceMin, bcdDeviceMax, \
48 		    vendor_name, product_name, use_protocol, use_transport, \
49 		    init_function, Flags) \
50 { \
51 	.vendorName = vendor_name,	\
52 	.productName = product_name,	\
53 	.useProtocol = use_protocol,	\
54 	.useTransport = use_transport,	\
55 	.initFunction = init_function,	\
56 }
57 
58 static struct us_unusual_dev cypress_unusual_dev_list[] = {
59 #	include "unusual_cypress.h"
60 	{ }		/* Terminating entry */
61 };
62 
63 #undef UNUSUAL_DEV
64 
65 
66 /*
67  * ATACB is a protocol used on cypress usb<->ata bridge to
68  * send raw ATA command over mass storage
69  * There is a ATACB2 protocol that support LBA48 on newer chip.
70  * More info that be found on cy7c68310_8.pdf and cy7c68300c_8.pdf
71  * datasheet from cypress.com.
72  */
cypress_atacb_passthrough(struct scsi_cmnd * srb,struct us_data * us)73 static void cypress_atacb_passthrough(struct scsi_cmnd *srb, struct us_data *us)
74 {
75 	unsigned char save_cmnd[MAX_COMMAND_SIZE];
76 
77 	if (likely(srb->cmnd[0] != ATA_16 && srb->cmnd[0] != ATA_12)) {
78 		usb_stor_transparent_scsi_command(srb, us);
79 		return;
80 	}
81 
82 	memcpy(save_cmnd, srb->cmnd, sizeof(save_cmnd));
83 	memset(srb->cmnd, 0, MAX_COMMAND_SIZE);
84 
85 	/* check if we support the command */
86 	if (save_cmnd[1] >> 5) /* MULTIPLE_COUNT */
87 		goto invalid_fld;
88 	/* check protocol */
89 	switch ((save_cmnd[1] >> 1) & 0xf) {
90 	case 3: /*no DATA */
91 	case 4: /* PIO in */
92 	case 5: /* PIO out */
93 		break;
94 	default:
95 		goto invalid_fld;
96 	}
97 
98 	/* first build the ATACB command */
99 	srb->cmd_len = 16;
100 
101 	srb->cmnd[0] = 0x24; /*
102 			      * bVSCBSignature : vendor-specific command
103 			      * this value can change, but most(all ?) manufacturers
104 			      * keep the cypress default : 0x24
105 			      */
106 	srb->cmnd[1] = 0x24; /* bVSCBSubCommand : 0x24 for ATACB */
107 
108 	srb->cmnd[3] = 0xff - 1; /*
109 				  * features, sector count, lba low, lba med
110 				  * lba high, device, command are valid
111 				  */
112 	srb->cmnd[4] = 1; /* TransferBlockCount : 512 */
113 
114 	if (save_cmnd[0] == ATA_16) {
115 		srb->cmnd[ 6] = save_cmnd[ 4]; /* features */
116 		srb->cmnd[ 7] = save_cmnd[ 6]; /* sector count */
117 		srb->cmnd[ 8] = save_cmnd[ 8]; /* lba low */
118 		srb->cmnd[ 9] = save_cmnd[10]; /* lba med */
119 		srb->cmnd[10] = save_cmnd[12]; /* lba high */
120 		srb->cmnd[11] = save_cmnd[13]; /* device */
121 		srb->cmnd[12] = save_cmnd[14]; /* command */
122 
123 		if (save_cmnd[1] & 0x01) {/* extended bit set for LBA48 */
124 			/* this could be supported by atacb2 */
125 			if (save_cmnd[3] || save_cmnd[5] || save_cmnd[7] || save_cmnd[9]
126 					|| save_cmnd[11])
127 				goto invalid_fld;
128 		}
129 	} else { /* ATA12 */
130 		srb->cmnd[ 6] = save_cmnd[3]; /* features */
131 		srb->cmnd[ 7] = save_cmnd[4]; /* sector count */
132 		srb->cmnd[ 8] = save_cmnd[5]; /* lba low */
133 		srb->cmnd[ 9] = save_cmnd[6]; /* lba med */
134 		srb->cmnd[10] = save_cmnd[7]; /* lba high */
135 		srb->cmnd[11] = save_cmnd[8]; /* device */
136 		srb->cmnd[12] = save_cmnd[9]; /* command */
137 
138 	}
139 	/* Filter SET_FEATURES - XFER MODE command */
140 	if ((srb->cmnd[12] == ATA_CMD_SET_FEATURES)
141 			&& (srb->cmnd[6] == SETFEATURES_XFER))
142 		goto invalid_fld;
143 
144 	if (srb->cmnd[12] == ATA_CMD_ID_ATA || srb->cmnd[12] == ATA_CMD_ID_ATAPI)
145 		srb->cmnd[2] |= (1<<7); /* set  IdentifyPacketDevice for these cmds */
146 
147 
148 	usb_stor_transparent_scsi_command(srb, us);
149 
150 	/* if the device doesn't support ATACB */
151 	if (srb->result == SAM_STAT_CHECK_CONDITION &&
152 			memcmp(srb->sense_buffer, usb_stor_sense_invalidCDB,
153 				sizeof(usb_stor_sense_invalidCDB)) == 0) {
154 		usb_stor_dbg(us, "cypress atacb not supported ???\n");
155 		goto end;
156 	}
157 
158 	/*
159 	 * if ck_cond flags is set, and there wasn't critical error,
160 	 * build the special sense
161 	 */
162 	if ((srb->result != (DID_ERROR << 16) &&
163 				srb->result != (DID_ABORT << 16)) &&
164 			save_cmnd[2] & 0x20) {
165 		struct scsi_eh_save ses;
166 		unsigned char regs[8];
167 		unsigned char *sb = srb->sense_buffer;
168 		unsigned char *desc = sb + 8;
169 		int tmp_result;
170 
171 		/* build the command for reading the ATA registers */
172 		scsi_eh_prep_cmnd(srb, &ses, NULL, 0, sizeof(regs));
173 
174 		/*
175 		 * we use the same command as before, but we set
176 		 * the read taskfile bit, for not executing atacb command,
177 		 * but reading register selected in srb->cmnd[4]
178 		 */
179 		srb->cmd_len = 16;
180 		srb->cmnd = ses.cmnd;
181 		srb->cmnd[2] = 1;
182 
183 		usb_stor_transparent_scsi_command(srb, us);
184 		memcpy(regs, srb->sense_buffer, sizeof(regs));
185 		tmp_result = srb->result;
186 		scsi_eh_restore_cmnd(srb, &ses);
187 		/* we fail to get registers, report invalid command */
188 		if (tmp_result != SAM_STAT_GOOD)
189 			goto invalid_fld;
190 
191 		/* build the sense */
192 		memset(sb, 0, SCSI_SENSE_BUFFERSIZE);
193 
194 		/* set sk, asc for a good command */
195 		sb[1] = RECOVERED_ERROR;
196 		sb[2] = 0; /* ATA PASS THROUGH INFORMATION AVAILABLE */
197 		sb[3] = 0x1D;
198 
199 		/*
200 		 * XXX we should generate sk, asc, ascq from status and error
201 		 * regs
202 		 * (see 11.1 Error translation ATA device error to SCSI error
203 		 * map, and ata_to_sense_error from libata.)
204 		 */
205 
206 		/* Sense data is current and format is descriptor. */
207 		sb[0] = 0x72;
208 		desc[0] = 0x09; /* ATA_RETURN_DESCRIPTOR */
209 
210 		/* set length of additional sense data */
211 		sb[7] = 14;
212 		desc[1] = 12;
213 
214 		/* Copy registers into sense buffer. */
215 		desc[ 2] = 0x00;
216 		desc[ 3] = regs[1];  /* features */
217 		desc[ 5] = regs[2];  /* sector count */
218 		desc[ 7] = regs[3];  /* lba low */
219 		desc[ 9] = regs[4];  /* lba med */
220 		desc[11] = regs[5];  /* lba high */
221 		desc[12] = regs[6];  /* device */
222 		desc[13] = regs[7];  /* command */
223 
224 		srb->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
225 	}
226 	goto end;
227 invalid_fld:
228 	srb->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
229 
230 	memcpy(srb->sense_buffer,
231 			usb_stor_sense_invalidCDB,
232 			sizeof(usb_stor_sense_invalidCDB));
233 end:
234 	memcpy(srb->cmnd, save_cmnd, sizeof(save_cmnd));
235 	if (srb->cmnd[0] == ATA_12)
236 		srb->cmd_len = 12;
237 }
238 
239 static struct scsi_host_template cypress_host_template;
240 
cypress_probe(struct usb_interface * intf,const struct usb_device_id * id)241 static int cypress_probe(struct usb_interface *intf,
242 			 const struct usb_device_id *id)
243 {
244 	struct us_data *us;
245 	int result;
246 	struct usb_device *device;
247 
248 	result = usb_stor_probe1(&us, intf, id,
249 			(id - cypress_usb_ids) + cypress_unusual_dev_list,
250 			&cypress_host_template);
251 	if (result)
252 		return result;
253 
254 	/*
255 	 * Among CY7C68300 chips, the A revision does not support Cypress ATACB
256 	 * Filter out this revision from EEPROM default descriptor values
257 	 */
258 	device = interface_to_usbdev(intf);
259 	if (device->descriptor.iManufacturer != 0x38 ||
260 	    device->descriptor.iProduct != 0x4e ||
261 	    device->descriptor.iSerialNumber != 0x64) {
262 		us->protocol_name = "Transparent SCSI with Cypress ATACB";
263 		us->proto_handler = cypress_atacb_passthrough;
264 	} else {
265 		us->protocol_name = "Transparent SCSI";
266 		us->proto_handler = usb_stor_transparent_scsi_command;
267 	}
268 
269 	result = usb_stor_probe2(us);
270 	return result;
271 }
272 
273 static struct usb_driver cypress_driver = {
274 	.name =		DRV_NAME,
275 	.probe =	cypress_probe,
276 	.disconnect =	usb_stor_disconnect,
277 	.suspend =	usb_stor_suspend,
278 	.resume =	usb_stor_resume,
279 	.reset_resume =	usb_stor_reset_resume,
280 	.pre_reset =	usb_stor_pre_reset,
281 	.post_reset =	usb_stor_post_reset,
282 	.id_table =	cypress_usb_ids,
283 	.soft_unbind =	1,
284 	.no_dynamic_id = 1,
285 };
286 
287 module_usb_stor_driver(cypress_driver, cypress_host_template, DRV_NAME);
288