xref: /openbmc/linux/drivers/char/tpm/tpm_nsc.c (revision 275876e2)
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 <linux/slab.h>
24 #include "tpm.h"
25 
26 /* National definitions */
27 enum tpm_nsc_addr{
28 	TPM_NSC_IRQ = 0x07,
29 	TPM_NSC_BASE0_HI = 0x60,
30 	TPM_NSC_BASE0_LO = 0x61,
31 	TPM_NSC_BASE1_HI = 0x62,
32 	TPM_NSC_BASE1_LO = 0x63
33 };
34 
35 enum tpm_nsc_index {
36 	NSC_LDN_INDEX = 0x07,
37 	NSC_SID_INDEX = 0x20,
38 	NSC_LDC_INDEX = 0x30,
39 	NSC_DIO_INDEX = 0x60,
40 	NSC_CIO_INDEX = 0x62,
41 	NSC_IRQ_INDEX = 0x70,
42 	NSC_ITS_INDEX = 0x71
43 };
44 
45 enum tpm_nsc_status_loc {
46 	NSC_STATUS = 0x01,
47 	NSC_COMMAND = 0x01,
48 	NSC_DATA = 0x00
49 };
50 
51 /* status bits */
52 enum tpm_nsc_status {
53 	NSC_STATUS_OBF = 0x01,	/* output buffer full */
54 	NSC_STATUS_IBF = 0x02,	/* input buffer full */
55 	NSC_STATUS_F0 = 0x04,	/* F0 */
56 	NSC_STATUS_A2 = 0x08,	/* A2 */
57 	NSC_STATUS_RDY = 0x10,	/* ready to receive command */
58 	NSC_STATUS_IBR = 0x20	/* ready to receive data */
59 };
60 
61 /* command bits */
62 enum tpm_nsc_cmd_mode {
63 	NSC_COMMAND_NORMAL = 0x01,	/* normal mode */
64 	NSC_COMMAND_EOC = 0x03,
65 	NSC_COMMAND_CANCEL = 0x22
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 	unsigned long stop;
73 
74 	/* status immediately available check */
75 	*data = inb(chip->vendor.base + NSC_STATUS);
76 	if ((*data & mask) == val)
77 		return 0;
78 
79 	/* wait for status */
80 	stop = jiffies + 10 * HZ;
81 	do {
82 		msleep(TPM_TIMEOUT);
83 		*data = inb(chip->vendor.base + 1);
84 		if ((*data & mask) == val)
85 			return 0;
86 	}
87 	while (time_before(jiffies, stop));
88 
89 	return -EBUSY;
90 }
91 
92 static int nsc_wait_for_ready(struct tpm_chip *chip)
93 {
94 	int status;
95 	unsigned long stop;
96 
97 	/* status immediately available check */
98 	status = inb(chip->vendor.base + NSC_STATUS);
99 	if (status & NSC_STATUS_OBF)
100 		status = inb(chip->vendor.base + NSC_DATA);
101 	if (status & NSC_STATUS_RDY)
102 		return 0;
103 
104 	/* wait for status */
105 	stop = jiffies + 100;
106 	do {
107 		msleep(TPM_TIMEOUT);
108 		status = inb(chip->vendor.base + NSC_STATUS);
109 		if (status & NSC_STATUS_OBF)
110 			status = inb(chip->vendor.base + NSC_DATA);
111 		if (status & NSC_STATUS_RDY)
112 			return 0;
113 	}
114 	while (time_before(jiffies, stop));
115 
116 	dev_info(chip->dev, "wait for ready failed\n");
117 	return -EBUSY;
118 }
119 
120 
121 static int tpm_nsc_recv(struct tpm_chip *chip, u8 * buf, size_t count)
122 {
123 	u8 *buffer = buf;
124 	u8 data, *p;
125 	u32 size;
126 	__be32 *native_size;
127 
128 	if (count < 6)
129 		return -EIO;
130 
131 	if (wait_for_stat(chip, NSC_STATUS_F0, NSC_STATUS_F0, &data) < 0) {
132 		dev_err(chip->dev, "F0 timeout\n");
133 		return -EIO;
134 	}
135 	if ((data =
136 	     inb(chip->vendor.base + NSC_DATA)) != NSC_COMMAND_NORMAL) {
137 		dev_err(chip->dev, "not in normal mode (0x%x)\n",
138 			data);
139 		return -EIO;
140 	}
141 
142 	/* read the whole packet */
143 	for (p = buffer; p < &buffer[count]; p++) {
144 		if (wait_for_stat
145 		    (chip, NSC_STATUS_OBF, NSC_STATUS_OBF, &data) < 0) {
146 			dev_err(chip->dev,
147 				"OBF timeout (while reading data)\n");
148 			return -EIO;
149 		}
150 		if (data & NSC_STATUS_F0)
151 			break;
152 		*p = inb(chip->vendor.base + NSC_DATA);
153 	}
154 
155 	if ((data & NSC_STATUS_F0) == 0 &&
156 	(wait_for_stat(chip, NSC_STATUS_F0, NSC_STATUS_F0, &data) < 0)) {
157 		dev_err(chip->dev, "F0 not set\n");
158 		return -EIO;
159 	}
160 	if ((data = inb(chip->vendor.base + NSC_DATA)) != NSC_COMMAND_EOC) {
161 		dev_err(chip->dev,
162 			"expected end of command(0x%x)\n", data);
163 		return -EIO;
164 	}
165 
166 	native_size = (__force __be32 *) (buf + 2);
167 	size = be32_to_cpu(*native_size);
168 
169 	if (count < size)
170 		return -EIO;
171 
172 	return size;
173 }
174 
175 static int tpm_nsc_send(struct tpm_chip *chip, u8 * buf, size_t count)
176 {
177 	u8 data;
178 	int i;
179 
180 	/*
181 	 * If we hit the chip with back to back commands it locks up
182 	 * and never set IBF. Hitting it with this "hammer" seems to
183 	 * fix it. Not sure why this is needed, we followed the flow
184 	 * chart in the manual to the letter.
185 	 */
186 	outb(NSC_COMMAND_CANCEL, chip->vendor.base + NSC_COMMAND);
187 
188 	if (nsc_wait_for_ready(chip) != 0)
189 		return -EIO;
190 
191 	if (wait_for_stat(chip, NSC_STATUS_IBF, 0, &data) < 0) {
192 		dev_err(chip->dev, "IBF timeout\n");
193 		return -EIO;
194 	}
195 
196 	outb(NSC_COMMAND_NORMAL, chip->vendor.base + NSC_COMMAND);
197 	if (wait_for_stat(chip, NSC_STATUS_IBR, NSC_STATUS_IBR, &data) < 0) {
198 		dev_err(chip->dev, "IBR timeout\n");
199 		return -EIO;
200 	}
201 
202 	for (i = 0; i < count; i++) {
203 		if (wait_for_stat(chip, NSC_STATUS_IBF, 0, &data) < 0) {
204 			dev_err(chip->dev,
205 				"IBF timeout (while writing data)\n");
206 			return -EIO;
207 		}
208 		outb(buf[i], chip->vendor.base + NSC_DATA);
209 	}
210 
211 	if (wait_for_stat(chip, NSC_STATUS_IBF, 0, &data) < 0) {
212 		dev_err(chip->dev, "IBF timeout\n");
213 		return -EIO;
214 	}
215 	outb(NSC_COMMAND_EOC, chip->vendor.base + NSC_COMMAND);
216 
217 	return count;
218 }
219 
220 static void tpm_nsc_cancel(struct tpm_chip *chip)
221 {
222 	outb(NSC_COMMAND_CANCEL, chip->vendor.base + NSC_COMMAND);
223 }
224 
225 static u8 tpm_nsc_status(struct tpm_chip *chip)
226 {
227 	return inb(chip->vendor.base + NSC_STATUS);
228 }
229 
230 static bool tpm_nsc_req_canceled(struct tpm_chip *chip, u8 status)
231 {
232 	return (status == NSC_STATUS_RDY);
233 }
234 
235 static const struct tpm_class_ops tpm_nsc = {
236 	.recv = tpm_nsc_recv,
237 	.send = tpm_nsc_send,
238 	.cancel = tpm_nsc_cancel,
239 	.status = tpm_nsc_status,
240 	.req_complete_mask = NSC_STATUS_OBF,
241 	.req_complete_val = NSC_STATUS_OBF,
242 	.req_canceled = tpm_nsc_req_canceled,
243 };
244 
245 static struct platform_device *pdev = NULL;
246 
247 static void tpm_nsc_remove(struct device *dev)
248 {
249 	struct tpm_chip *chip = dev_get_drvdata(dev);
250 	if ( chip ) {
251 		release_region(chip->vendor.base, 2);
252 		tpm_remove_hardware(chip->dev);
253 	}
254 }
255 
256 static SIMPLE_DEV_PM_OPS(tpm_nsc_pm, tpm_pm_suspend, tpm_pm_resume);
257 
258 static struct platform_driver nsc_drv = {
259 	.driver          = {
260 		.name    = "tpm_nsc",
261 		.owner   = THIS_MODULE,
262 		.pm      = &tpm_nsc_pm,
263 	},
264 };
265 
266 static int __init init_nsc(void)
267 {
268 	int rc = 0;
269 	int lo, hi, err;
270 	int nscAddrBase = TPM_ADDR;
271 	struct tpm_chip *chip;
272 	unsigned long base;
273 
274 	/* verify that it is a National part (SID) */
275 	if (tpm_read_index(TPM_ADDR, NSC_SID_INDEX) != 0xEF) {
276 		nscAddrBase = (tpm_read_index(TPM_SUPERIO_ADDR, 0x2C)<<8)|
277 			(tpm_read_index(TPM_SUPERIO_ADDR, 0x2B)&0xFE);
278 		if (tpm_read_index(nscAddrBase, NSC_SID_INDEX) != 0xF6)
279 			return -ENODEV;
280 	}
281 
282 	err = platform_driver_register(&nsc_drv);
283 	if (err)
284 		return err;
285 
286 	hi = tpm_read_index(nscAddrBase, TPM_NSC_BASE0_HI);
287 	lo = tpm_read_index(nscAddrBase, TPM_NSC_BASE0_LO);
288 	base = (hi<<8) | lo;
289 
290 	/* enable the DPM module */
291 	tpm_write_index(nscAddrBase, NSC_LDC_INDEX, 0x01);
292 
293 	pdev = platform_device_alloc("tpm_nscl0", -1);
294 	if (!pdev) {
295 		rc = -ENOMEM;
296 		goto err_unreg_drv;
297 	}
298 
299 	pdev->num_resources = 0;
300 	pdev->dev.driver = &nsc_drv.driver;
301 	pdev->dev.release = tpm_nsc_remove;
302 
303 	if ((rc = platform_device_add(pdev)) < 0)
304 		goto err_put_dev;
305 
306 	if (request_region(base, 2, "tpm_nsc0") == NULL ) {
307 		rc = -EBUSY;
308 		goto err_del_dev;
309 	}
310 
311 	if (!(chip = tpm_register_hardware(&pdev->dev, &tpm_nsc))) {
312 		rc = -ENODEV;
313 		goto err_rel_reg;
314 	}
315 
316 	dev_dbg(&pdev->dev, "NSC TPM detected\n");
317 	dev_dbg(&pdev->dev,
318 		"NSC LDN 0x%x, SID 0x%x, SRID 0x%x\n",
319 		tpm_read_index(nscAddrBase,0x07), tpm_read_index(nscAddrBase,0x20),
320 		tpm_read_index(nscAddrBase,0x27));
321 	dev_dbg(&pdev->dev,
322 		"NSC SIOCF1 0x%x SIOCF5 0x%x SIOCF6 0x%x SIOCF8 0x%x\n",
323 		tpm_read_index(nscAddrBase,0x21), tpm_read_index(nscAddrBase,0x25),
324 		tpm_read_index(nscAddrBase,0x26), tpm_read_index(nscAddrBase,0x28));
325 	dev_dbg(&pdev->dev, "NSC IO Base0 0x%x\n",
326 		(tpm_read_index(nscAddrBase,0x60) << 8) | tpm_read_index(nscAddrBase,0x61));
327 	dev_dbg(&pdev->dev, "NSC IO Base1 0x%x\n",
328 		(tpm_read_index(nscAddrBase,0x62) << 8) | tpm_read_index(nscAddrBase,0x63));
329 	dev_dbg(&pdev->dev, "NSC Interrupt number and wakeup 0x%x\n",
330 		tpm_read_index(nscAddrBase,0x70));
331 	dev_dbg(&pdev->dev, "NSC IRQ type select 0x%x\n",
332 		tpm_read_index(nscAddrBase,0x71));
333 	dev_dbg(&pdev->dev,
334 		"NSC DMA channel select0 0x%x, select1 0x%x\n",
335 		tpm_read_index(nscAddrBase,0x74), tpm_read_index(nscAddrBase,0x75));
336 	dev_dbg(&pdev->dev,
337 		"NSC Config "
338 		"0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x 0x%x\n",
339 		tpm_read_index(nscAddrBase,0xF0), tpm_read_index(nscAddrBase,0xF1),
340 		tpm_read_index(nscAddrBase,0xF2), tpm_read_index(nscAddrBase,0xF3),
341 		tpm_read_index(nscAddrBase,0xF4), tpm_read_index(nscAddrBase,0xF5),
342 		tpm_read_index(nscAddrBase,0xF6), tpm_read_index(nscAddrBase,0xF7),
343 		tpm_read_index(nscAddrBase,0xF8), tpm_read_index(nscAddrBase,0xF9));
344 
345 	dev_info(&pdev->dev,
346 		 "NSC TPM revision %d\n",
347 		 tpm_read_index(nscAddrBase, 0x27) & 0x1F);
348 
349 	chip->vendor.base = base;
350 
351 	return 0;
352 
353 err_rel_reg:
354 	release_region(base, 2);
355 err_del_dev:
356 	platform_device_del(pdev);
357 err_put_dev:
358 	platform_device_put(pdev);
359 err_unreg_drv:
360 	platform_driver_unregister(&nsc_drv);
361 	return rc;
362 }
363 
364 static void __exit cleanup_nsc(void)
365 {
366 	if (pdev) {
367 		tpm_nsc_remove(&pdev->dev);
368 		platform_device_unregister(pdev);
369 	}
370 
371 	platform_driver_unregister(&nsc_drv);
372 }
373 
374 module_init(init_nsc);
375 module_exit(cleanup_nsc);
376 
377 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
378 MODULE_DESCRIPTION("TPM Driver");
379 MODULE_VERSION("2.0");
380 MODULE_LICENSE("GPL");
381