summaryrefslogtreecommitdiff
path: root/drivers/char/tpm/tpm_atmel.c
blob: 54a6750a67578114b12b6be5a684ed9ac349ca33 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2004 IBM Corporation
 *
 * Authors:
 * Leendert van Doorn <leendert@watson.ibm.com>
 * Dave Safford <safford@watson.ibm.com>
 * Reiner Sailer <sailer@watson.ibm.com>
 * Kylene Hall <kjhall@us.ibm.com>
 *
 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
 *
 * Device driver for TCG/TCPA TPM (trusted platform module).
 * Specifications at www.trustedcomputinggroup.org	 
 */

#include "tpm.h"
#include "tpm_atmel.h"

/* write status bits */
enum tpm_atmel_write_status {
	ATML_STATUS_ABORT = 0x01,
	ATML_STATUS_LASTBYTE = 0x04
};
/* read status bits */
enum tpm_atmel_read_status {
	ATML_STATUS_BUSY = 0x01,
	ATML_STATUS_DATA_AVAIL = 0x02,
	ATML_STATUS_REWRITE = 0x04,
	ATML_STATUS_READY = 0x08
};

static int tpm_atml_recv(struct tpm_chip *chip, u8 *buf, size_t count)
{
	struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
	u8 status, *hdr = buf;
	u32 size;
	int i;
	__be32 *native_size;

	/* start reading header */
	if (count < 6)
		return -EIO;

	for (i = 0; i < 6; i++) {
		status = ioread8(priv->iobase + 1);
		if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
			dev_err(&chip->dev, "error reading header\n");
			return -EIO;
		}
		*buf++ = ioread8(priv->iobase);
	}

	/* size of the data received */
	native_size = (__force __be32 *) (hdr + 2);
	size = be32_to_cpu(*native_size);

	if (count < size) {
		dev_err(&chip->dev,
			"Recv size(%d) less than available space\n", size);
		for (; i < size; i++) {	/* clear the waiting data anyway */
			status = ioread8(priv->iobase + 1);
			if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
				dev_err(&chip->dev, "error reading data\n");
				return -EIO;
			}
		}
		return -EIO;
	}

	/* read all the data available */
	for (; i < size; i++) {
		status = ioread8(priv->iobase + 1);
		if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
			dev_err(&chip->dev, "error reading data\n");
			return -EIO;
		}
		*buf++ = ioread8(priv->iobase);
	}

	/* make sure data available is gone */
	status = ioread8(priv->iobase + 1);

	if (status & ATML_STATUS_DATA_AVAIL) {
		dev_err(&chip->dev, "data available is stuck\n");
		return -EIO;
	}

	return size;
}

static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t count)
{
	struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
	int i;

	dev_dbg(&chip->dev, "tpm_atml_send:\n");
	for (i = 0; i < count; i++) {
		dev_dbg(&chip->dev, "%d 0x%x(%d)\n",  i, buf[i], buf[i]);
		iowrite8(buf[i], priv->iobase);
	}

	return 0;
}

static void tpm_atml_cancel(struct tpm_chip *chip)
{
	struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);

	iowrite8(ATML_STATUS_ABORT, priv->iobase + 1);
}

static u8 tpm_atml_status(struct tpm_chip *chip)
{
	struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);

	return ioread8(priv->iobase + 1);
}

static bool tpm_atml_req_canceled(struct tpm_chip *chip, u8 status)
{
	return (status == ATML_STATUS_READY);
}

static const struct tpm_class_ops tpm_atmel = {
	.recv = tpm_atml_recv,
	.send = tpm_atml_send,
	.cancel = tpm_atml_cancel,
	.status = tpm_atml_status,
	.req_complete_mask = ATML_STATUS_BUSY | ATML_STATUS_DATA_AVAIL,
	.req_complete_val = ATML_STATUS_DATA_AVAIL,
	.req_canceled = tpm_atml_req_canceled,
};

static struct platform_device *pdev;

static void atml_plat_remove(void)
{
	struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
	struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);

	tpm_chip_unregister(chip);
	if (priv->have_region)
		atmel_release_region(priv->base, priv->region_size);
	atmel_put_base_addr(priv->iobase);
	platform_device_unregister(pdev);
}

static SIMPLE_DEV_PM_OPS(tpm_atml_pm, tpm_pm_suspend, tpm_pm_resume);

static struct platform_driver atml_drv = {
	.driver = {
		.name = "tpm_atmel",
		.pm		= &tpm_atml_pm,
	},
};

static int __init init_atmel(void)
{
	int rc = 0;
	void __iomem *iobase = NULL;
	int have_region, region_size;
	unsigned long base;
	struct  tpm_chip *chip;
	struct tpm_atmel_priv *priv;

	rc = platform_driver_register(&atml_drv);
	if (rc)
		return rc;

	if ((iobase = atmel_get_base_addr(&base, &region_size)) == NULL) {
		rc = -ENODEV;
		goto err_unreg_drv;
	}

	have_region =
	    (atmel_request_region
	     (base, region_size, "tpm_atmel0") == NULL) ? 0 : 1;

	pdev = platform_device_register_simple("tpm_atmel", -1, NULL, 0);
	if (IS_ERR(pdev)) {
		rc = PTR_ERR(pdev);
		goto err_rel_reg;
	}

	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv) {
		rc = -ENOMEM;
		goto err_unreg_dev;
	}

	priv->iobase = iobase;
	priv->base = base;
	priv->have_region = have_region;
	priv->region_size = region_size;

	chip = tpmm_chip_alloc(&pdev->dev, &tpm_atmel);
	if (IS_ERR(chip)) {
		rc = PTR_ERR(chip);
		goto err_unreg_dev;
	}

	dev_set_drvdata(&chip->dev, priv);

	rc = tpm_chip_register(chip);
	if (rc)
		goto err_unreg_dev;

	return 0;

err_unreg_dev:
	platform_device_unregister(pdev);
err_rel_reg:
	atmel_put_base_addr(iobase);
	if (have_region)
		atmel_release_region(base,
				     region_size);
err_unreg_drv:
	platform_driver_unregister(&atml_drv);
	return rc;
}

static void __exit cleanup_atmel(void)
{
	platform_driver_unregister(&atml_drv);
	atml_plat_remove();
}

module_init(init_atmel);
module_exit(cleanup_atmel);

MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
MODULE_DESCRIPTION("TPM Driver");
MODULE_VERSION("2.0");
MODULE_LICENSE("GPL");