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
22MODULE_DESCRIPTION("SAT support for Cypress USB/ATA bridges with ATACB");
23MODULE_AUTHOR("Matthieu Castet <castet.matthieu@free.fr>");
24MODULE_LICENSE("GPL");
25MODULE_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
36static struct usb_device_id cypress_usb_ids[] = {
37#	include "unusual_cypress.h"
38	{ }		/* Terminating entry */
39};
40MODULE_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
58static 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 */
73static 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[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 = SAM_STAT_CHECK_CONDITION;
224	}
225	goto end;
226invalid_fld:
227	srb->result = SAM_STAT_CHECK_CONDITION;
228
229	memcpy(srb->sense_buffer,
230			usb_stor_sense_invalidCDB,
231			sizeof(usb_stor_sense_invalidCDB));
232end:
233	memcpy(srb->cmnd, save_cmnd, sizeof(save_cmnd));
234	if (srb->cmnd[0] == ATA_12)
235		srb->cmd_len = 12;
236}
237
238static struct scsi_host_template cypress_host_template;
239
240static 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
272static 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
286module_usb_stor_driver(cypress_driver, cypress_host_template, DRV_NAME);
287