xref: /linux/drivers/char/tpm/tpm_atmel.c (revision c7fb577e2a6cb04732541f2dc402bd46747f7558)
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 "tpm.h"
23 
24 /* Atmel definitions */
25 enum tpm_atmel_addr {
26 	TPM_ATMEL_BASE_ADDR_LO = 0x08,
27 	TPM_ATMEL_BASE_ADDR_HI = 0x09
28 };
29 
30 /* write status bits */
31 enum tpm_atmel_write_status {
32 	ATML_STATUS_ABORT = 0x01,
33 	ATML_STATUS_LASTBYTE = 0x04
34 };
35 /* read status bits */
36 enum tpm_atmel_read_status {
37 	ATML_STATUS_BUSY = 0x01,
38 	ATML_STATUS_DATA_AVAIL = 0x02,
39 	ATML_STATUS_REWRITE = 0x04,
40 	ATML_STATUS_READY = 0x08
41 };
42 
43 static int tpm_atml_recv(struct tpm_chip *chip, u8 *buf, size_t count)
44 {
45 	u8 status, *hdr = buf;
46 	u32 size;
47 	int i;
48 	__be32 *native_size;
49 
50 	/* start reading header */
51 	if (count < 6)
52 		return -EIO;
53 
54 	for (i = 0; i < 6; i++) {
55 		status = inb(chip->vendor->base + 1);
56 		if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
57 			dev_err(chip->dev,
58 				"error reading header\n");
59 			return -EIO;
60 		}
61 		*buf++ = inb(chip->vendor->base);
62 	}
63 
64 	/* size of the data received */
65 	native_size = (__force __be32 *) (hdr + 2);
66 	size = be32_to_cpu(*native_size);
67 
68 	if (count < size) {
69 		dev_err(chip->dev,
70 			"Recv size(%d) less than available space\n", size);
71 		for (; i < size; i++) {	/* clear the waiting data anyway */
72 			status = inb(chip->vendor->base + 1);
73 			if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
74 				dev_err(chip->dev,
75 					"error reading data\n");
76 				return -EIO;
77 			}
78 		}
79 		return -EIO;
80 	}
81 
82 	/* read all the data available */
83 	for (; i < size; i++) {
84 		status = inb(chip->vendor->base + 1);
85 		if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
86 			dev_err(chip->dev,
87 				"error reading data\n");
88 			return -EIO;
89 		}
90 		*buf++ = inb(chip->vendor->base);
91 	}
92 
93 	/* make sure data available is gone */
94 	status = inb(chip->vendor->base + 1);
95 	if (status & ATML_STATUS_DATA_AVAIL) {
96 		dev_err(chip->dev, "data available is stuck\n");
97 		return -EIO;
98 	}
99 
100 	return size;
101 }
102 
103 static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t count)
104 {
105 	int i;
106 
107 	dev_dbg(chip->dev, "tpm_atml_send:\n");
108 	for (i = 0; i < count; i++) {
109 		dev_dbg(chip->dev, "%d 0x%x(%d)\n",  i, buf[i], buf[i]);
110 		outb(buf[i], chip->vendor->base);
111 	}
112 
113 	return count;
114 }
115 
116 static void tpm_atml_cancel(struct tpm_chip *chip)
117 {
118 	outb(ATML_STATUS_ABORT, chip->vendor->base + 1);
119 }
120 
121 static u8 tpm_atml_status(struct tpm_chip *chip)
122 {
123 	return inb(chip->vendor->base + 1);
124 }
125 
126 static struct file_operations atmel_ops = {
127 	.owner = THIS_MODULE,
128 	.llseek = no_llseek,
129 	.open = tpm_open,
130 	.read = tpm_read,
131 	.write = tpm_write,
132 	.release = tpm_release,
133 };
134 
135 static DEVICE_ATTR(pubek, S_IRUGO, tpm_show_pubek, NULL);
136 static DEVICE_ATTR(pcrs, S_IRUGO, tpm_show_pcrs, NULL);
137 static DEVICE_ATTR(caps, S_IRUGO, tpm_show_caps, NULL);
138 static DEVICE_ATTR(cancel, S_IWUSR |S_IWGRP, NULL, tpm_store_cancel);
139 
140 static struct attribute* atmel_attrs[] = {
141 	&dev_attr_pubek.attr,
142 	&dev_attr_pcrs.attr,
143 	&dev_attr_caps.attr,
144 	&dev_attr_cancel.attr,
145 	NULL,
146 };
147 
148 static struct attribute_group atmel_attr_grp = { .attrs = atmel_attrs };
149 
150 static struct tpm_vendor_specific tpm_atmel = {
151 	.recv = tpm_atml_recv,
152 	.send = tpm_atml_send,
153 	.cancel = tpm_atml_cancel,
154 	.status = tpm_atml_status,
155 	.req_complete_mask = ATML_STATUS_BUSY | ATML_STATUS_DATA_AVAIL,
156 	.req_complete_val = ATML_STATUS_DATA_AVAIL,
157 	.req_canceled = ATML_STATUS_READY,
158 	.attr_group = &atmel_attr_grp,
159 	.miscdev = { .fops = &atmel_ops, },
160 };
161 
162 static struct platform_device *pdev;
163 
164 static void __devexit tpm_atml_remove(struct device *dev)
165 {
166 	struct tpm_chip *chip = dev_get_drvdata(dev);
167 	if (chip) {
168 		release_region(chip->vendor->base, 2);
169 		tpm_remove_hardware(chip->dev);
170 	}
171 }
172 
173 static struct device_driver atml_drv = {
174 	.name = "tpm_atmel",
175 	.bus = &platform_bus_type,
176 	.owner = THIS_MODULE,
177 	.suspend = tpm_pm_suspend,
178 	.resume = tpm_pm_resume,
179 };
180 
181 static int __init init_atmel(void)
182 {
183 	int rc = 0;
184 	int lo, hi;
185 
186 	driver_register(&atml_drv);
187 
188 	lo = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_LO);
189 	hi = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_HI);
190 
191 	tpm_atmel.base = (hi<<8)|lo;
192 
193 	/* verify that it is an Atmel part */
194 	if (tpm_read_index(TPM_ADDR, 4) != 'A' || tpm_read_index(TPM_ADDR, 5) != 'T'
195 	    || tpm_read_index(TPM_ADDR, 6) != 'M' || tpm_read_index(TPM_ADDR, 7) != 'L') {
196 		return -ENODEV;
197 	}
198 
199 	/* verify chip version number is 1.1 */
200 	if (	(tpm_read_index(TPM_ADDR, 0x00) != 0x01) ||
201 		(tpm_read_index(TPM_ADDR, 0x01) != 0x01 ))
202 		return -ENODEV;
203 
204 	pdev = kzalloc(sizeof(struct platform_device), GFP_KERNEL);
205 	if ( !pdev )
206 		return -ENOMEM;
207 
208 	pdev->name = "tpm_atmel0";
209 	pdev->id = -1;
210 	pdev->num_resources = 0;
211 	pdev->dev.release = tpm_atml_remove;
212 	pdev->dev.driver = &atml_drv;
213 
214 	if ((rc = platform_device_register(pdev)) < 0) {
215 		kfree(pdev);
216 		pdev = NULL;
217 		return rc;
218 	}
219 
220 	if (request_region(tpm_atmel.base, 2, "tpm_atmel0") == NULL ) {
221 		platform_device_unregister(pdev);
222 		kfree(pdev);
223 		pdev = NULL;
224 		return -EBUSY;
225 	}
226 
227 	if ((rc = tpm_register_hardware(&pdev->dev, &tpm_atmel)) < 0) {
228 		release_region(tpm_atmel.base, 2);
229 		platform_device_unregister(pdev);
230 		kfree(pdev);
231 		pdev = NULL;
232 		return rc;
233 	}
234 
235 	dev_info(&pdev->dev, "Atmel TPM 1.1, Base Address: 0x%x\n",
236 			tpm_atmel.base);
237 	return 0;
238 }
239 
240 static void __exit cleanup_atmel(void)
241 {
242 	if (pdev) {
243 		tpm_atml_remove(&pdev->dev);
244 		platform_device_unregister(pdev);
245 		kfree(pdev);
246 		pdev = NULL;
247 	}
248 
249 	driver_unregister(&atml_drv);
250 }
251 
252 module_init(init_atmel);
253 module_exit(cleanup_atmel);
254 
255 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
256 MODULE_DESCRIPTION("TPM Driver");
257 MODULE_VERSION("2.0");
258 MODULE_LICENSE("GPL");
259