xref: /linux/drivers/char/tpm/tpm_nsc.c (revision 4d40b59d8b0568769d10ac9b2a97e0af0a39d371)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2004 IBM Corporation
4  *
5  * Authors:
6  * Leendert van Doorn <leendert@watson.ibm.com>
7  * Dave Safford <safford@watson.ibm.com>
8  * Reiner Sailer <sailer@watson.ibm.com>
9  * Kylene Hall <kjhall@us.ibm.com>
10  *
11  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
12  *
13  * Device driver for TCG/TCPA TPM (trusted platform module).
14  * Specifications at www.trustedcomputinggroup.org
15  */
16 
17 #include <linux/platform_device.h>
18 #include <linux/slab.h>
19 #include "tpm.h"
20 
21 /* National definitions */
22 enum tpm_nsc_addr{
23 	TPM_NSC_IRQ = 0x07,
24 	TPM_NSC_BASE0_HI = 0x60,
25 	TPM_NSC_BASE0_LO = 0x61,
26 	TPM_NSC_BASE1_HI = 0x62,
27 	TPM_NSC_BASE1_LO = 0x63
28 };
29 
30 enum tpm_nsc_index {
31 	NSC_LDN_INDEX = 0x07,
32 	NSC_SID_INDEX = 0x20,
33 	NSC_LDC_INDEX = 0x30,
34 	NSC_DIO_INDEX = 0x60,
35 	NSC_CIO_INDEX = 0x62,
36 	NSC_IRQ_INDEX = 0x70,
37 	NSC_ITS_INDEX = 0x71
38 };
39 
40 enum tpm_nsc_status_loc {
41 	NSC_STATUS = 0x01,
42 	NSC_COMMAND = 0x01,
43 	NSC_DATA = 0x00
44 };
45 
46 /* status bits */
47 enum tpm_nsc_status {
48 	NSC_STATUS_OBF = 0x01,	/* output buffer full */
49 	NSC_STATUS_IBF = 0x02,	/* input buffer full */
50 	NSC_STATUS_F0 = 0x04,	/* F0 */
51 	NSC_STATUS_A2 = 0x08,	/* A2 */
52 	NSC_STATUS_RDY = 0x10,	/* ready to receive command */
53 	NSC_STATUS_IBR = 0x20	/* ready to receive data */
54 };
55 
56 /* command bits */
57 enum tpm_nsc_cmd_mode {
58 	NSC_COMMAND_NORMAL = 0x01,	/* normal mode */
59 	NSC_COMMAND_EOC = 0x03,
60 	NSC_COMMAND_CANCEL = 0x22
61 };
62 
63 struct tpm_nsc_priv {
64 	unsigned long base;
65 };
66 
67 /*
68  * Wait for a certain status to appear
69  */
wait_for_stat(struct tpm_chip * chip,u8 mask,u8 val,u8 * data)70 static int wait_for_stat(struct tpm_chip *chip, u8 mask, u8 val, u8 * data)
71 {
72 	struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
73 	unsigned long stop;
74 
75 	/* status immediately available check */
76 	*data = inb(priv->base + NSC_STATUS);
77 	if ((*data & mask) == val)
78 		return 0;
79 
80 	/* wait for status */
81 	stop = jiffies + 10 * HZ;
82 	do {
83 		msleep(TPM_TIMEOUT);
84 		*data = inb(priv->base + 1);
85 		if ((*data & mask) == val)
86 			return 0;
87 	}
88 	while (time_before(jiffies, stop));
89 
90 	return -EBUSY;
91 }
92 
nsc_wait_for_ready(struct tpm_chip * chip)93 static int nsc_wait_for_ready(struct tpm_chip *chip)
94 {
95 	struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
96 	int status;
97 	unsigned long stop;
98 
99 	/* status immediately available check */
100 	status = inb(priv->base + NSC_STATUS);
101 	if (status & NSC_STATUS_OBF)
102 		status = inb(priv->base + NSC_DATA);
103 	if (status & NSC_STATUS_RDY)
104 		return 0;
105 
106 	/* wait for status */
107 	stop = jiffies + 100;
108 	do {
109 		msleep(TPM_TIMEOUT);
110 		status = inb(priv->base + NSC_STATUS);
111 		if (status & NSC_STATUS_OBF)
112 			status = inb(priv->base + NSC_DATA);
113 		if (status & NSC_STATUS_RDY)
114 			return 0;
115 	}
116 	while (time_before(jiffies, stop));
117 
118 	dev_info(&chip->dev, "wait for ready failed\n");
119 	return -EBUSY;
120 }
121 
122 
tpm_nsc_recv(struct tpm_chip * chip,u8 * buf,size_t count)123 static int tpm_nsc_recv(struct tpm_chip *chip, u8 * buf, size_t count)
124 {
125 	struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
126 	u8 *buffer = buf;
127 	u8 data, *p;
128 	u32 size;
129 	__be32 *native_size;
130 
131 	if (count < 6)
132 		return -EIO;
133 
134 	if (wait_for_stat(chip, NSC_STATUS_F0, NSC_STATUS_F0, &data) < 0) {
135 		dev_err(&chip->dev, "F0 timeout\n");
136 		return -EIO;
137 	}
138 
139 	data = inb(priv->base + NSC_DATA);
140 	if (data != NSC_COMMAND_NORMAL) {
141 		dev_err(&chip->dev, "not in normal mode (0x%x)\n",
142 			data);
143 		return -EIO;
144 	}
145 
146 	/* read the whole packet */
147 	for (p = buffer; p < &buffer[count]; p++) {
148 		if (wait_for_stat
149 		    (chip, NSC_STATUS_OBF, NSC_STATUS_OBF, &data) < 0) {
150 			dev_err(&chip->dev,
151 				"OBF timeout (while reading data)\n");
152 			return -EIO;
153 		}
154 		if (data & NSC_STATUS_F0)
155 			break;
156 		*p = inb(priv->base + NSC_DATA);
157 	}
158 
159 	if ((data & NSC_STATUS_F0) == 0 &&
160 	(wait_for_stat(chip, NSC_STATUS_F0, NSC_STATUS_F0, &data) < 0)) {
161 		dev_err(&chip->dev, "F0 not set\n");
162 		return -EIO;
163 	}
164 
165 	data = inb(priv->base + NSC_DATA);
166 	if (data != NSC_COMMAND_EOC) {
167 		dev_err(&chip->dev,
168 			"expected end of command(0x%x)\n", data);
169 		return -EIO;
170 	}
171 
172 	native_size = (__force __be32 *) (buf + 2);
173 	size = be32_to_cpu(*native_size);
174 
175 	if (count < size)
176 		return -EIO;
177 
178 	return size;
179 }
180 
tpm_nsc_send(struct tpm_chip * chip,u8 * buf,size_t bufsiz,size_t count)181 static int tpm_nsc_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
182 			size_t count)
183 {
184 	struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
185 	u8 data;
186 	int i;
187 
188 	/*
189 	 * If we hit the chip with back to back commands it locks up
190 	 * and never set IBF. Hitting it with this "hammer" seems to
191 	 * fix it. Not sure why this is needed, we followed the flow
192 	 * chart in the manual to the letter.
193 	 */
194 	outb(NSC_COMMAND_CANCEL, priv->base + NSC_COMMAND);
195 
196 	if (nsc_wait_for_ready(chip) != 0)
197 		return -EIO;
198 
199 	if (wait_for_stat(chip, NSC_STATUS_IBF, 0, &data) < 0) {
200 		dev_err(&chip->dev, "IBF timeout\n");
201 		return -EIO;
202 	}
203 
204 	outb(NSC_COMMAND_NORMAL, priv->base + NSC_COMMAND);
205 	if (wait_for_stat(chip, NSC_STATUS_IBR, NSC_STATUS_IBR, &data) < 0) {
206 		dev_err(&chip->dev, "IBR timeout\n");
207 		return -EIO;
208 	}
209 
210 	for (i = 0; i < count; i++) {
211 		if (wait_for_stat(chip, NSC_STATUS_IBF, 0, &data) < 0) {
212 			dev_err(&chip->dev,
213 				"IBF timeout (while writing data)\n");
214 			return -EIO;
215 		}
216 		outb(buf[i], priv->base + NSC_DATA);
217 	}
218 
219 	if (wait_for_stat(chip, NSC_STATUS_IBF, 0, &data) < 0) {
220 		dev_err(&chip->dev, "IBF timeout\n");
221 		return -EIO;
222 	}
223 	outb(NSC_COMMAND_EOC, priv->base + NSC_COMMAND);
224 
225 	return 0;
226 }
227 
tpm_nsc_cancel(struct tpm_chip * chip)228 static void tpm_nsc_cancel(struct tpm_chip *chip)
229 {
230 	struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
231 
232 	outb(NSC_COMMAND_CANCEL, priv->base + NSC_COMMAND);
233 }
234 
tpm_nsc_status(struct tpm_chip * chip)235 static u8 tpm_nsc_status(struct tpm_chip *chip)
236 {
237 	struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
238 
239 	return inb(priv->base + NSC_STATUS);
240 }
241 
tpm_nsc_req_canceled(struct tpm_chip * chip,u8 status)242 static bool tpm_nsc_req_canceled(struct tpm_chip *chip, u8 status)
243 {
244 	return (status == NSC_STATUS_RDY);
245 }
246 
247 static const struct tpm_class_ops tpm_nsc = {
248 	.recv = tpm_nsc_recv,
249 	.send = tpm_nsc_send,
250 	.cancel = tpm_nsc_cancel,
251 	.status = tpm_nsc_status,
252 	.req_complete_mask = NSC_STATUS_OBF,
253 	.req_complete_val = NSC_STATUS_OBF,
254 	.req_canceled = tpm_nsc_req_canceled,
255 };
256 
257 static struct platform_device *pdev = NULL;
258 
tpm_nsc_remove(struct device * dev)259 static void tpm_nsc_remove(struct device *dev)
260 {
261 	struct tpm_chip *chip = dev_get_drvdata(dev);
262 	struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
263 
264 	tpm_chip_unregister(chip);
265 	release_region(priv->base, 2);
266 }
267 
268 static SIMPLE_DEV_PM_OPS(tpm_nsc_pm, tpm_pm_suspend, tpm_pm_resume);
269 
270 static struct platform_driver nsc_drv = {
271 	.driver          = {
272 		.name    = "tpm_nsc",
273 		.pm      = &tpm_nsc_pm,
274 	},
275 };
276 
tpm_read_index(int base,int index)277 static inline int tpm_read_index(int base, int index)
278 {
279 	outb(index, base);
280 	return inb(base+1) & 0xFF;
281 }
282 
tpm_write_index(int base,int index,int value)283 static inline void tpm_write_index(int base, int index, int value)
284 {
285 	outb(index, base);
286 	outb(value & 0xFF, base+1);
287 }
288 
init_nsc(void)289 static int __init init_nsc(void)
290 {
291 	int rc = 0;
292 	int lo, hi, err;
293 	int nscAddrBase = TPM_ADDR;
294 	struct tpm_chip *chip;
295 	unsigned long base;
296 	struct tpm_nsc_priv *priv;
297 
298 	/* verify that it is a National part (SID) */
299 	if (tpm_read_index(TPM_ADDR, NSC_SID_INDEX) != 0xEF) {
300 		nscAddrBase = (tpm_read_index(TPM_SUPERIO_ADDR, 0x2C)<<8)|
301 			(tpm_read_index(TPM_SUPERIO_ADDR, 0x2B)&0xFE);
302 		if (tpm_read_index(nscAddrBase, NSC_SID_INDEX) != 0xF6)
303 			return -ENODEV;
304 	}
305 
306 	err = platform_driver_register(&nsc_drv);
307 	if (err)
308 		return err;
309 
310 	hi = tpm_read_index(nscAddrBase, TPM_NSC_BASE0_HI);
311 	lo = tpm_read_index(nscAddrBase, TPM_NSC_BASE0_LO);
312 	base = (hi<<8) | lo;
313 
314 	/* enable the DPM module */
315 	tpm_write_index(nscAddrBase, NSC_LDC_INDEX, 0x01);
316 
317 	pdev = platform_device_alloc("tpm_nscl0", -1);
318 	if (!pdev) {
319 		rc = -ENOMEM;
320 		goto err_unreg_drv;
321 	}
322 
323 	pdev->num_resources = 0;
324 	pdev->dev.driver = &nsc_drv.driver;
325 	pdev->dev.release = tpm_nsc_remove;
326 
327 	if ((rc = platform_device_add(pdev)) < 0)
328 		goto err_put_dev;
329 
330 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
331 	if (!priv) {
332 		rc = -ENOMEM;
333 		goto err_del_dev;
334 	}
335 
336 	priv->base = base;
337 
338 	if (request_region(base, 2, "tpm_nsc0") == NULL ) {
339 		rc = -EBUSY;
340 		goto err_del_dev;
341 	}
342 
343 	chip = tpmm_chip_alloc(&pdev->dev, &tpm_nsc);
344 	if (IS_ERR(chip)) {
345 		rc = -ENODEV;
346 		goto err_rel_reg;
347 	}
348 
349 	dev_set_drvdata(&chip->dev, priv);
350 
351 	rc = tpm_chip_register(chip);
352 	if (rc)
353 		goto err_rel_reg;
354 
355 	dev_dbg(&pdev->dev, "NSC TPM detected\n");
356 	dev_dbg(&pdev->dev,
357 		"NSC LDN 0x%x, SID 0x%x, SRID 0x%x\n",
358 		tpm_read_index(nscAddrBase,0x07), tpm_read_index(nscAddrBase,0x20),
359 		tpm_read_index(nscAddrBase,0x27));
360 	dev_dbg(&pdev->dev,
361 		"NSC SIOCF1 0x%x SIOCF5 0x%x SIOCF6 0x%x SIOCF8 0x%x\n",
362 		tpm_read_index(nscAddrBase,0x21), tpm_read_index(nscAddrBase,0x25),
363 		tpm_read_index(nscAddrBase,0x26), tpm_read_index(nscAddrBase,0x28));
364 	dev_dbg(&pdev->dev, "NSC IO Base0 0x%x\n",
365 		(tpm_read_index(nscAddrBase,0x60) << 8) | tpm_read_index(nscAddrBase,0x61));
366 	dev_dbg(&pdev->dev, "NSC IO Base1 0x%x\n",
367 		(tpm_read_index(nscAddrBase,0x62) << 8) | tpm_read_index(nscAddrBase,0x63));
368 	dev_dbg(&pdev->dev, "NSC Interrupt number and wakeup 0x%x\n",
369 		tpm_read_index(nscAddrBase,0x70));
370 	dev_dbg(&pdev->dev, "NSC IRQ type select 0x%x\n",
371 		tpm_read_index(nscAddrBase,0x71));
372 	dev_dbg(&pdev->dev,
373 		"NSC DMA channel select0 0x%x, select1 0x%x\n",
374 		tpm_read_index(nscAddrBase,0x74), tpm_read_index(nscAddrBase,0x75));
375 	dev_dbg(&pdev->dev,
376 		"NSC Config "
377 		"0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x\n",
378 		tpm_read_index(nscAddrBase,0xF0), tpm_read_index(nscAddrBase,0xF1),
379 		tpm_read_index(nscAddrBase,0xF2), tpm_read_index(nscAddrBase,0xF3),
380 		tpm_read_index(nscAddrBase,0xF4), tpm_read_index(nscAddrBase,0xF5),
381 		tpm_read_index(nscAddrBase,0xF6), tpm_read_index(nscAddrBase,0xF7),
382 		tpm_read_index(nscAddrBase,0xF8), tpm_read_index(nscAddrBase,0xF9));
383 
384 	dev_info(&pdev->dev,
385 		 "NSC TPM revision %d\n",
386 		 tpm_read_index(nscAddrBase, 0x27) & 0x1F);
387 
388 	return 0;
389 
390 err_rel_reg:
391 	release_region(base, 2);
392 err_del_dev:
393 	platform_device_del(pdev);
394 err_put_dev:
395 	platform_device_put(pdev);
396 err_unreg_drv:
397 	platform_driver_unregister(&nsc_drv);
398 	return rc;
399 }
400 
cleanup_nsc(void)401 static void __exit cleanup_nsc(void)
402 {
403 	if (pdev) {
404 		tpm_nsc_remove(&pdev->dev);
405 		platform_device_unregister(pdev);
406 	}
407 
408 	platform_driver_unregister(&nsc_drv);
409 }
410 
411 module_init(init_nsc);
412 module_exit(cleanup_nsc);
413 
414 MODULE_AUTHOR("Leendert van Doorn <leendert@watson.ibm.com>");
415 MODULE_DESCRIPTION("TPM Driver");
416 MODULE_VERSION("2.0");
417 MODULE_LICENSE("GPL");
418