xref: /openbmc/linux/drivers/char/tpm/tpm_nsc.c (revision e15a5365) 
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  */
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 
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 
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 
181 static int tpm_nsc_send(struct tpm_chip *chip, u8 * buf, size_t count)
182 {
183 	struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
184 	u8 data;
185 	int i;
186 
187 	/*
188 	 * If we hit the chip with back to back commands it locks up
189 	 * and never set IBF. Hitting it with this "hammer" seems to
190 	 * fix it. Not sure why this is needed, we followed the flow
191 	 * chart in the manual to the letter.
192 	 */
193 	outb(NSC_COMMAND_CANCEL, priv->base + NSC_COMMAND);
194 
195 	if (nsc_wait_for_ready(chip) != 0)
196 		return -EIO;
197 
198 	if (wait_for_stat(chip, NSC_STATUS_IBF, 0, &data) < 0) {
199 		dev_err(&chip->dev, "IBF timeout\n");
200 		return -EIO;
201 	}
202 
203 	outb(NSC_COMMAND_NORMAL, priv->base + NSC_COMMAND);
204 	if (wait_for_stat(chip, NSC_STATUS_IBR, NSC_STATUS_IBR, &data) < 0) {
205 		dev_err(&chip->dev, "IBR timeout\n");
206 		return -EIO;
207 	}
208 
209 	for (i = 0; i < count; i++) {
210 		if (wait_for_stat(chip, NSC_STATUS_IBF, 0, &data) < 0) {
211 			dev_err(&chip->dev,
212 				"IBF timeout (while writing data)\n");
213 			return -EIO;
214 		}
215 		outb(buf[i], priv->base + NSC_DATA);
216 	}
217 
218 	if (wait_for_stat(chip, NSC_STATUS_IBF, 0, &data) < 0) {
219 		dev_err(&chip->dev, "IBF timeout\n");
220 		return -EIO;
221 	}
222 	outb(NSC_COMMAND_EOC, priv->base + NSC_COMMAND);
223 
224 	return 0;
225 }
226 
227 static void tpm_nsc_cancel(struct tpm_chip *chip)
228 {
229 	struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
230 
231 	outb(NSC_COMMAND_CANCEL, priv->base + NSC_COMMAND);
232 }
233 
234 static u8 tpm_nsc_status(struct tpm_chip *chip)
235 {
236 	struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
237 
238 	return inb(priv->base + NSC_STATUS);
239 }
240 
241 static bool tpm_nsc_req_canceled(struct tpm_chip *chip, u8 status)
242 {
243 	return (status == NSC_STATUS_RDY);
244 }
245 
246 static const struct tpm_class_ops tpm_nsc = {
247 	.recv = tpm_nsc_recv,
248 	.send = tpm_nsc_send,
249 	.cancel = tpm_nsc_cancel,
250 	.status = tpm_nsc_status,
251 	.req_complete_mask = NSC_STATUS_OBF,
252 	.req_complete_val = NSC_STATUS_OBF,
253 	.req_canceled = tpm_nsc_req_canceled,
254 };
255 
256 static struct platform_device *pdev = NULL;
257 
258 static void tpm_nsc_remove(struct device *dev)
259 {
260 	struct tpm_chip *chip = dev_get_drvdata(dev);
261 	struct tpm_nsc_priv *priv = dev_get_drvdata(&chip->dev);
262 
263 	tpm_chip_unregister(chip);
264 	release_region(priv->base, 2);
265 }
266 
267 static SIMPLE_DEV_PM_OPS(tpm_nsc_pm, tpm_pm_suspend, tpm_pm_resume);
268 
269 static struct platform_driver nsc_drv = {
270 	.driver          = {
271 		.name    = "tpm_nsc",
272 		.pm      = &tpm_nsc_pm,
273 	},
274 };
275 
276 static inline int tpm_read_index(int base, int index)
277 {
278 	outb(index, base);
279 	return inb(base+1) & 0xFF;
280 }
281 
282 static inline void tpm_write_index(int base, int index, int value)
283 {
284 	outb(index, base);
285 	outb(value & 0xFF, base+1);
286 }
287 
288 static int __init init_nsc(void)
289 {
290 	int rc = 0;
291 	int lo, hi, err;
292 	int nscAddrBase = TPM_ADDR;
293 	struct tpm_chip *chip;
294 	unsigned long base;
295 	struct tpm_nsc_priv *priv;
296 
297 	/* verify that it is a National part (SID) */
298 	if (tpm_read_index(TPM_ADDR, NSC_SID_INDEX) != 0xEF) {
299 		nscAddrBase = (tpm_read_index(TPM_SUPERIO_ADDR, 0x2C)<<8)|
300 			(tpm_read_index(TPM_SUPERIO_ADDR, 0x2B)&0xFE);
301 		if (tpm_read_index(nscAddrBase, NSC_SID_INDEX) != 0xF6)
302 			return -ENODEV;
303 	}
304 
305 	err = platform_driver_register(&nsc_drv);
306 	if (err)
307 		return err;
308 
309 	hi = tpm_read_index(nscAddrBase, TPM_NSC_BASE0_HI);
310 	lo = tpm_read_index(nscAddrBase, TPM_NSC_BASE0_LO);
311 	base = (hi<<8) | lo;
312 
313 	/* enable the DPM module */
314 	tpm_write_index(nscAddrBase, NSC_LDC_INDEX, 0x01);
315 
316 	pdev = platform_device_alloc("tpm_nscl0", -1);
317 	if (!pdev) {
318 		rc = -ENOMEM;
319 		goto err_unreg_drv;
320 	}
321 
322 	pdev->num_resources = 0;
323 	pdev->dev.driver = &nsc_drv.driver;
324 	pdev->dev.release = tpm_nsc_remove;
325 
326 	if ((rc = platform_device_add(pdev)) < 0)
327 		goto err_put_dev;
328 
329 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
330 	if (!priv) {
331 		rc = -ENOMEM;
332 		goto err_del_dev;
333 	}
334 
335 	priv->base = base;
336 
337 	if (request_region(base, 2, "tpm_nsc0") == NULL ) {
338 		rc = -EBUSY;
339 		goto err_del_dev;
340 	}
341 
342 	chip = tpmm_chip_alloc(&pdev->dev, &tpm_nsc);
343 	if (IS_ERR(chip)) {
344 		rc = -ENODEV;
345 		goto err_rel_reg;
346 	}
347 
348 	dev_set_drvdata(&chip->dev, priv);
349 
350 	rc = tpm_chip_register(chip);
351 	if (rc)
352 		goto err_rel_reg;
353 
354 	dev_dbg(&pdev->dev, "NSC TPM detected\n");
355 	dev_dbg(&pdev->dev,
356 		"NSC LDN 0x%x, SID 0x%x, SRID 0x%x\n",
357 		tpm_read_index(nscAddrBase,0x07), tpm_read_index(nscAddrBase,0x20),
358 		tpm_read_index(nscAddrBase,0x27));
359 	dev_dbg(&pdev->dev,
360 		"NSC SIOCF1 0x%x SIOCF5 0x%x SIOCF6 0x%x SIOCF8 0x%x\n",
361 		tpm_read_index(nscAddrBase,0x21), tpm_read_index(nscAddrBase,0x25),
362 		tpm_read_index(nscAddrBase,0x26), tpm_read_index(nscAddrBase,0x28));
363 	dev_dbg(&pdev->dev, "NSC IO Base0 0x%x\n",
364 		(tpm_read_index(nscAddrBase,0x60) << 8) | tpm_read_index(nscAddrBase,0x61));
365 	dev_dbg(&pdev->dev, "NSC IO Base1 0x%x\n",
366 		(tpm_read_index(nscAddrBase,0x62) << 8) | tpm_read_index(nscAddrBase,0x63));
367 	dev_dbg(&pdev->dev, "NSC Interrupt number and wakeup 0x%x\n",
368 		tpm_read_index(nscAddrBase,0x70));
369 	dev_dbg(&pdev->dev, "NSC IRQ type select 0x%x\n",
370 		tpm_read_index(nscAddrBase,0x71));
371 	dev_dbg(&pdev->dev,
372 		"NSC DMA channel select0 0x%x, select1 0x%x\n",
373 		tpm_read_index(nscAddrBase,0x74), tpm_read_index(nscAddrBase,0x75));
374 	dev_dbg(&pdev->dev,
375 		"NSC Config "
376 		"0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x\n",
377 		tpm_read_index(nscAddrBase,0xF0), tpm_read_index(nscAddrBase,0xF1),
378 		tpm_read_index(nscAddrBase,0xF2), tpm_read_index(nscAddrBase,0xF3),
379 		tpm_read_index(nscAddrBase,0xF4), tpm_read_index(nscAddrBase,0xF5),
380 		tpm_read_index(nscAddrBase,0xF6), tpm_read_index(nscAddrBase,0xF7),
381 		tpm_read_index(nscAddrBase,0xF8), tpm_read_index(nscAddrBase,0xF9));
382 
383 	dev_info(&pdev->dev,
384 		 "NSC TPM revision %d\n",
385 		 tpm_read_index(nscAddrBase, 0x27) & 0x1F);
386 
387 	return 0;
388 
389 err_rel_reg:
390 	release_region(base, 2);
391 err_del_dev:
392 	platform_device_del(pdev);
393 err_put_dev:
394 	platform_device_put(pdev);
395 err_unreg_drv:
396 	platform_driver_unregister(&nsc_drv);
397 	return rc;
398 }
399 
400 static void __exit cleanup_nsc(void)
401 {
402 	if (pdev) {
403 		tpm_nsc_remove(&pdev->dev);
404 		platform_device_unregister(pdev);
405 	}
406 
407 	platform_driver_unregister(&nsc_drv);
408 }
409 
410 module_init(init_nsc);
411 module_exit(cleanup_nsc);
412 
413 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
414 MODULE_DESCRIPTION("TPM Driver");
415 MODULE_VERSION("2.0");
416 MODULE_LICENSE("GPL");
417