xref: /openbmc/linux/drivers/char/tpm/tpm_nsc.c (revision 22246614)
1 /*
2  * Copyright (C) 2004 IBM Corporation
3  *
4  * Authors:
5  * Leendert van Doorn <leendert@watson.ibm.com>
6  * Dave Safford <safford@watson.ibm.com>
7  * Reiner Sailer <sailer@watson.ibm.com>
8  * Kylene Hall <kjhall@us.ibm.com>
9  *
10  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
11  *
12  * Device driver for TCG/TCPA TPM (trusted platform module).
13  * Specifications at www.trustedcomputinggroup.org
14  *
15  * This program is free software; you can redistribute it and/or
16  * modify it under the terms of the GNU General Public License as
17  * published by the Free Software Foundation, version 2 of the
18  * License.
19  *
20  */
21 
22 #include <linux/platform_device.h>
23 #include "tpm.h"
24 
25 /* National definitions */
26 enum tpm_nsc_addr{
27 	TPM_NSC_IRQ = 0x07,
28 	TPM_NSC_BASE0_HI = 0x60,
29 	TPM_NSC_BASE0_LO = 0x61,
30 	TPM_NSC_BASE1_HI = 0x62,
31 	TPM_NSC_BASE1_LO = 0x63
32 };
33 
34 enum tpm_nsc_index {
35 	NSC_LDN_INDEX = 0x07,
36 	NSC_SID_INDEX = 0x20,
37 	NSC_LDC_INDEX = 0x30,
38 	NSC_DIO_INDEX = 0x60,
39 	NSC_CIO_INDEX = 0x62,
40 	NSC_IRQ_INDEX = 0x70,
41 	NSC_ITS_INDEX = 0x71
42 };
43 
44 enum tpm_nsc_status_loc {
45 	NSC_STATUS = 0x01,
46 	NSC_COMMAND = 0x01,
47 	NSC_DATA = 0x00
48 };
49 
50 /* status bits */
51 enum tpm_nsc_status {
52 	NSC_STATUS_OBF = 0x01,	/* output buffer full */
53 	NSC_STATUS_IBF = 0x02,	/* input buffer full */
54 	NSC_STATUS_F0 = 0x04,	/* F0 */
55 	NSC_STATUS_A2 = 0x08,	/* A2 */
56 	NSC_STATUS_RDY = 0x10,	/* ready to receive command */
57 	NSC_STATUS_IBR = 0x20	/* ready to receive data */
58 };
59 
60 /* command bits */
61 enum tpm_nsc_cmd_mode {
62 	NSC_COMMAND_NORMAL = 0x01,	/* normal mode */
63 	NSC_COMMAND_EOC = 0x03,
64 	NSC_COMMAND_CANCEL = 0x22
65 };
66 /*
67  * Wait for a certain status to appear
68  */
69 static int wait_for_stat(struct tpm_chip *chip, u8 mask, u8 val, u8 * data)
70 {
71 	unsigned long stop;
72 
73 	/* status immediately available check */
74 	*data = inb(chip->vendor.base + NSC_STATUS);
75 	if ((*data & mask) == val)
76 		return 0;
77 
78 	/* wait for status */
79 	stop = jiffies + 10 * HZ;
80 	do {
81 		msleep(TPM_TIMEOUT);
82 		*data = inb(chip->vendor.base + 1);
83 		if ((*data & mask) == val)
84 			return 0;
85 	}
86 	while (time_before(jiffies, stop));
87 
88 	return -EBUSY;
89 }
90 
91 static int nsc_wait_for_ready(struct tpm_chip *chip)
92 {
93 	int status;
94 	unsigned long stop;
95 
96 	/* status immediately available check */
97 	status = inb(chip->vendor.base + NSC_STATUS);
98 	if (status & NSC_STATUS_OBF)
99 		status = inb(chip->vendor.base + NSC_DATA);
100 	if (status & NSC_STATUS_RDY)
101 		return 0;
102 
103 	/* wait for status */
104 	stop = jiffies + 100;
105 	do {
106 		msleep(TPM_TIMEOUT);
107 		status = inb(chip->vendor.base + NSC_STATUS);
108 		if (status & NSC_STATUS_OBF)
109 			status = inb(chip->vendor.base + NSC_DATA);
110 		if (status & NSC_STATUS_RDY)
111 			return 0;
112 	}
113 	while (time_before(jiffies, stop));
114 
115 	dev_info(chip->dev, "wait for ready failed\n");
116 	return -EBUSY;
117 }
118 
119 
120 static int tpm_nsc_recv(struct tpm_chip *chip, u8 * buf, size_t count)
121 {
122 	u8 *buffer = buf;
123 	u8 data, *p;
124 	u32 size;
125 	__be32 *native_size;
126 
127 	if (count < 6)
128 		return -EIO;
129 
130 	if (wait_for_stat(chip, NSC_STATUS_F0, NSC_STATUS_F0, &data) < 0) {
131 		dev_err(chip->dev, "F0 timeout\n");
132 		return -EIO;
133 	}
134 	if ((data =
135 	     inb(chip->vendor.base + NSC_DATA)) != NSC_COMMAND_NORMAL) {
136 		dev_err(chip->dev, "not in normal mode (0x%x)\n",
137 			data);
138 		return -EIO;
139 	}
140 
141 	/* read the whole packet */
142 	for (p = buffer; p < &buffer[count]; p++) {
143 		if (wait_for_stat
144 		    (chip, NSC_STATUS_OBF, NSC_STATUS_OBF, &data) < 0) {
145 			dev_err(chip->dev,
146 				"OBF timeout (while reading data)\n");
147 			return -EIO;
148 		}
149 		if (data & NSC_STATUS_F0)
150 			break;
151 		*p = inb(chip->vendor.base + NSC_DATA);
152 	}
153 
154 	if ((data & NSC_STATUS_F0) == 0 &&
155 	(wait_for_stat(chip, NSC_STATUS_F0, NSC_STATUS_F0, &data) < 0)) {
156 		dev_err(chip->dev, "F0 not set\n");
157 		return -EIO;
158 	}
159 	if ((data = inb(chip->vendor.base + NSC_DATA)) != NSC_COMMAND_EOC) {
160 		dev_err(chip->dev,
161 			"expected end of command(0x%x)\n", data);
162 		return -EIO;
163 	}
164 
165 	native_size = (__force __be32 *) (buf + 2);
166 	size = be32_to_cpu(*native_size);
167 
168 	if (count < size)
169 		return -EIO;
170 
171 	return size;
172 }
173 
174 static int tpm_nsc_send(struct tpm_chip *chip, u8 * buf, size_t count)
175 {
176 	u8 data;
177 	int i;
178 
179 	/*
180 	 * If we hit the chip with back to back commands it locks up
181 	 * and never set IBF. Hitting it with this "hammer" seems to
182 	 * fix it. Not sure why this is needed, we followed the flow
183 	 * chart in the manual to the letter.
184 	 */
185 	outb(NSC_COMMAND_CANCEL, chip->vendor.base + NSC_COMMAND);
186 
187 	if (nsc_wait_for_ready(chip) != 0)
188 		return -EIO;
189 
190 	if (wait_for_stat(chip, NSC_STATUS_IBF, 0, &data) < 0) {
191 		dev_err(chip->dev, "IBF timeout\n");
192 		return -EIO;
193 	}
194 
195 	outb(NSC_COMMAND_NORMAL, chip->vendor.base + NSC_COMMAND);
196 	if (wait_for_stat(chip, NSC_STATUS_IBR, NSC_STATUS_IBR, &data) < 0) {
197 		dev_err(chip->dev, "IBR timeout\n");
198 		return -EIO;
199 	}
200 
201 	for (i = 0; i < count; i++) {
202 		if (wait_for_stat(chip, NSC_STATUS_IBF, 0, &data) < 0) {
203 			dev_err(chip->dev,
204 				"IBF timeout (while writing data)\n");
205 			return -EIO;
206 		}
207 		outb(buf[i], chip->vendor.base + NSC_DATA);
208 	}
209 
210 	if (wait_for_stat(chip, NSC_STATUS_IBF, 0, &data) < 0) {
211 		dev_err(chip->dev, "IBF timeout\n");
212 		return -EIO;
213 	}
214 	outb(NSC_COMMAND_EOC, chip->vendor.base + NSC_COMMAND);
215 
216 	return count;
217 }
218 
219 static void tpm_nsc_cancel(struct tpm_chip *chip)
220 {
221 	outb(NSC_COMMAND_CANCEL, chip->vendor.base + NSC_COMMAND);
222 }
223 
224 static u8 tpm_nsc_status(struct tpm_chip *chip)
225 {
226 	return inb(chip->vendor.base + NSC_STATUS);
227 }
228 
229 static const struct file_operations nsc_ops = {
230 	.owner = THIS_MODULE,
231 	.llseek = no_llseek,
232 	.open = tpm_open,
233 	.read = tpm_read,
234 	.write = tpm_write,
235 	.release = tpm_release,
236 };
237 
238 static DEVICE_ATTR(pubek, S_IRUGO, tpm_show_pubek, NULL);
239 static DEVICE_ATTR(pcrs, S_IRUGO, tpm_show_pcrs, NULL);
240 static DEVICE_ATTR(caps, S_IRUGO, tpm_show_caps, NULL);
241 static DEVICE_ATTR(cancel, S_IWUSR|S_IWGRP, NULL, tpm_store_cancel);
242 
243 static struct attribute * nsc_attrs[] = {
244 	&dev_attr_pubek.attr,
245 	&dev_attr_pcrs.attr,
246 	&dev_attr_caps.attr,
247 	&dev_attr_cancel.attr,
248 	NULL,
249 };
250 
251 static struct attribute_group nsc_attr_grp = { .attrs = nsc_attrs };
252 
253 static const struct tpm_vendor_specific tpm_nsc = {
254 	.recv = tpm_nsc_recv,
255 	.send = tpm_nsc_send,
256 	.cancel = tpm_nsc_cancel,
257 	.status = tpm_nsc_status,
258 	.req_complete_mask = NSC_STATUS_OBF,
259 	.req_complete_val = NSC_STATUS_OBF,
260 	.req_canceled = NSC_STATUS_RDY,
261 	.attr_group = &nsc_attr_grp,
262 	.miscdev = { .fops = &nsc_ops, },
263 };
264 
265 static struct platform_device *pdev = NULL;
266 
267 static void tpm_nsc_remove(struct device *dev)
268 {
269 	struct tpm_chip *chip = dev_get_drvdata(dev);
270 	if ( chip ) {
271 		release_region(chip->vendor.base, 2);
272 		tpm_remove_hardware(chip->dev);
273 	}
274 }
275 
276 static struct device_driver nsc_drv = {
277 	.name = "tpm_nsc",
278 	.bus = &platform_bus_type,
279 	.owner = THIS_MODULE,
280 	.suspend = tpm_pm_suspend,
281 	.resume = tpm_pm_resume,
282 };
283 
284 static int __init init_nsc(void)
285 {
286 	int rc = 0;
287 	int lo, hi, err;
288 	int nscAddrBase = TPM_ADDR;
289 	struct tpm_chip *chip;
290 	unsigned long base;
291 
292 	/* verify that it is a National part (SID) */
293 	if (tpm_read_index(TPM_ADDR, NSC_SID_INDEX) != 0xEF) {
294 		nscAddrBase = (tpm_read_index(TPM_SUPERIO_ADDR, 0x2C)<<8)|
295 			(tpm_read_index(TPM_SUPERIO_ADDR, 0x2B)&0xFE);
296 		if (tpm_read_index(nscAddrBase, NSC_SID_INDEX) != 0xF6)
297 			return -ENODEV;
298 	}
299 
300 	err = driver_register(&nsc_drv);
301 	if (err)
302 		return err;
303 
304 	hi = tpm_read_index(nscAddrBase, TPM_NSC_BASE0_HI);
305 	lo = tpm_read_index(nscAddrBase, TPM_NSC_BASE0_LO);
306 	base = (hi<<8) | lo;
307 
308 	/* enable the DPM module */
309 	tpm_write_index(nscAddrBase, NSC_LDC_INDEX, 0x01);
310 
311 	pdev = kzalloc(sizeof(struct platform_device), GFP_KERNEL);
312 	if (!pdev) {
313 		rc = -ENOMEM;
314 		goto err_unreg_drv;
315 	}
316 
317 	pdev->name = "tpm_nscl0";
318 	pdev->id = -1;
319 	pdev->num_resources = 0;
320 	pdev->dev.release = tpm_nsc_remove;
321 	pdev->dev.driver = &nsc_drv;
322 
323 	if ((rc = platform_device_register(pdev)) < 0)
324 		goto err_free_dev;
325 
326 	if (request_region(base, 2, "tpm_nsc0") == NULL ) {
327 		rc = -EBUSY;
328 		goto err_unreg_dev;
329 	}
330 
331 	if (!(chip = tpm_register_hardware(&pdev->dev, &tpm_nsc))) {
332 		rc = -ENODEV;
333 		goto err_rel_reg;
334 	}
335 
336 	dev_dbg(&pdev->dev, "NSC TPM detected\n");
337 	dev_dbg(&pdev->dev,
338 		"NSC LDN 0x%x, SID 0x%x, SRID 0x%x\n",
339 		tpm_read_index(nscAddrBase,0x07), tpm_read_index(nscAddrBase,0x20),
340 		tpm_read_index(nscAddrBase,0x27));
341 	dev_dbg(&pdev->dev,
342 		"NSC SIOCF1 0x%x SIOCF5 0x%x SIOCF6 0x%x SIOCF8 0x%x\n",
343 		tpm_read_index(nscAddrBase,0x21), tpm_read_index(nscAddrBase,0x25),
344 		tpm_read_index(nscAddrBase,0x26), tpm_read_index(nscAddrBase,0x28));
345 	dev_dbg(&pdev->dev, "NSC IO Base0 0x%x\n",
346 		(tpm_read_index(nscAddrBase,0x60) << 8) | tpm_read_index(nscAddrBase,0x61));
347 	dev_dbg(&pdev->dev, "NSC IO Base1 0x%x\n",
348 		(tpm_read_index(nscAddrBase,0x62) << 8) | tpm_read_index(nscAddrBase,0x63));
349 	dev_dbg(&pdev->dev, "NSC Interrupt number and wakeup 0x%x\n",
350 		tpm_read_index(nscAddrBase,0x70));
351 	dev_dbg(&pdev->dev, "NSC IRQ type select 0x%x\n",
352 		tpm_read_index(nscAddrBase,0x71));
353 	dev_dbg(&pdev->dev,
354 		"NSC DMA channel select0 0x%x, select1 0x%x\n",
355 		tpm_read_index(nscAddrBase,0x74), tpm_read_index(nscAddrBase,0x75));
356 	dev_dbg(&pdev->dev,
357 		"NSC Config "
358 		"0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x\n",
359 		tpm_read_index(nscAddrBase,0xF0), tpm_read_index(nscAddrBase,0xF1),
360 		tpm_read_index(nscAddrBase,0xF2), tpm_read_index(nscAddrBase,0xF3),
361 		tpm_read_index(nscAddrBase,0xF4), tpm_read_index(nscAddrBase,0xF5),
362 		tpm_read_index(nscAddrBase,0xF6), tpm_read_index(nscAddrBase,0xF7),
363 		tpm_read_index(nscAddrBase,0xF8), tpm_read_index(nscAddrBase,0xF9));
364 
365 	dev_info(&pdev->dev,
366 		 "NSC TPM revision %d\n",
367 		 tpm_read_index(nscAddrBase, 0x27) & 0x1F);
368 
369 	chip->vendor.base = base;
370 
371 	return 0;
372 
373 err_rel_reg:
374 	release_region(base, 2);
375 err_unreg_dev:
376 	platform_device_unregister(pdev);
377 err_free_dev:
378 	kfree(pdev);
379 err_unreg_drv:
380 	driver_unregister(&nsc_drv);
381 	return rc;
382 }
383 
384 static void __exit cleanup_nsc(void)
385 {
386 	if (pdev) {
387 		tpm_nsc_remove(&pdev->dev);
388 		platform_device_unregister(pdev);
389 		kfree(pdev);
390 		pdev = NULL;
391 	}
392 
393 	driver_unregister(&nsc_drv);
394 }
395 
396 module_init(init_nsc);
397 module_exit(cleanup_nsc);
398 
399 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
400 MODULE_DESCRIPTION("TPM Driver");
401 MODULE_VERSION("2.0");
402 MODULE_LICENSE("GPL");
403