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#include "tpm_atmel.h"
24
25/* write status bits */
26enum tpm_atmel_write_status {
27	ATML_STATUS_ABORT = 0x01,
28	ATML_STATUS_LASTBYTE = 0x04
29};
30/* read status bits */
31enum tpm_atmel_read_status {
32	ATML_STATUS_BUSY = 0x01,
33	ATML_STATUS_DATA_AVAIL = 0x02,
34	ATML_STATUS_REWRITE = 0x04,
35	ATML_STATUS_READY = 0x08
36};
37
38static int tpm_atml_recv(struct tpm_chip *chip, u8 *buf, size_t count)
39{
40	u8 status, *hdr = buf;
41	u32 size;
42	int i;
43	__be32 *native_size;
44
45	/* start reading header */
46	if (count < 6)
47		return -EIO;
48
49	for (i = 0; i < 6; i++) {
50		status = ioread8(chip->vendor.iobase + 1);
51		if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
52			dev_err(chip->dev, "error reading header\n");
53			return -EIO;
54		}
55		*buf++ = ioread8(chip->vendor.iobase);
56	}
57
58	/* size of the data received */
59	native_size = (__force __be32 *) (hdr + 2);
60	size = be32_to_cpu(*native_size);
61
62	if (count < size) {
63		dev_err(chip->dev,
64			"Recv size(%d) less than available space\n", size);
65		for (; i < size; i++) {	/* clear the waiting data anyway */
66			status = ioread8(chip->vendor.iobase + 1);
67			if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
68				dev_err(chip->dev, "error reading data\n");
69				return -EIO;
70			}
71		}
72		return -EIO;
73	}
74
75	/* read all the data available */
76	for (; i < size; i++) {
77		status = ioread8(chip->vendor.iobase + 1);
78		if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
79			dev_err(chip->dev, "error reading data\n");
80			return -EIO;
81		}
82		*buf++ = ioread8(chip->vendor.iobase);
83	}
84
85	/* make sure data available is gone */
86	status = ioread8(chip->vendor.iobase + 1);
87
88	if (status & ATML_STATUS_DATA_AVAIL) {
89		dev_err(chip->dev, "data available is stuck\n");
90		return -EIO;
91	}
92
93	return size;
94}
95
96static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t count)
97{
98	int i;
99
100	dev_dbg(chip->dev, "tpm_atml_send:\n");
101	for (i = 0; i < count; i++) {
102		dev_dbg(chip->dev, "%d 0x%x(%d)\n",  i, buf[i], buf[i]);
103 		iowrite8(buf[i], chip->vendor.iobase);
104	}
105
106	return count;
107}
108
109static void tpm_atml_cancel(struct tpm_chip *chip)
110{
111	iowrite8(ATML_STATUS_ABORT, chip->vendor.iobase + 1);
112}
113
114static u8 tpm_atml_status(struct tpm_chip *chip)
115{
116	return ioread8(chip->vendor.iobase + 1);
117}
118
119static bool tpm_atml_req_canceled(struct tpm_chip *chip, u8 status)
120{
121	return (status == ATML_STATUS_READY);
122}
123
124static const struct tpm_class_ops tpm_atmel = {
125	.recv = tpm_atml_recv,
126	.send = tpm_atml_send,
127	.cancel = tpm_atml_cancel,
128	.status = tpm_atml_status,
129	.req_complete_mask = ATML_STATUS_BUSY | ATML_STATUS_DATA_AVAIL,
130	.req_complete_val = ATML_STATUS_DATA_AVAIL,
131	.req_canceled = tpm_atml_req_canceled,
132};
133
134static struct platform_device *pdev;
135
136static void atml_plat_remove(void)
137{
138	struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
139
140	if (chip) {
141		if (chip->vendor.have_region)
142			atmel_release_region(chip->vendor.base,
143					     chip->vendor.region_size);
144		atmel_put_base_addr(chip->vendor.iobase);
145		tpm_remove_hardware(chip->dev);
146		platform_device_unregister(pdev);
147	}
148}
149
150static SIMPLE_DEV_PM_OPS(tpm_atml_pm, tpm_pm_suspend, tpm_pm_resume);
151
152static struct platform_driver atml_drv = {
153	.driver = {
154		.name = "tpm_atmel",
155		.owner		= THIS_MODULE,
156		.pm		= &tpm_atml_pm,
157	},
158};
159
160static int __init init_atmel(void)
161{
162	int rc = 0;
163	void __iomem *iobase = NULL;
164	int have_region, region_size;
165	unsigned long base;
166	struct  tpm_chip *chip;
167
168	rc = platform_driver_register(&atml_drv);
169	if (rc)
170		return rc;
171
172	if ((iobase = atmel_get_base_addr(&base, &region_size)) == NULL) {
173		rc = -ENODEV;
174		goto err_unreg_drv;
175	}
176
177	have_region =
178	    (atmel_request_region
179	     (base, region_size, "tpm_atmel0") == NULL) ? 0 : 1;
180
181	pdev = platform_device_register_simple("tpm_atmel", -1, NULL, 0);
182	if (IS_ERR(pdev)) {
183		rc = PTR_ERR(pdev);
184		goto err_rel_reg;
185	}
186
187	if (!(chip = tpm_register_hardware(&pdev->dev, &tpm_atmel))) {
188		rc = -ENODEV;
189		goto err_unreg_dev;
190	}
191
192	chip->vendor.iobase = iobase;
193	chip->vendor.base = base;
194	chip->vendor.have_region = have_region;
195	chip->vendor.region_size = region_size;
196
197	return 0;
198
199err_unreg_dev:
200	platform_device_unregister(pdev);
201err_rel_reg:
202	atmel_put_base_addr(iobase);
203	if (have_region)
204		atmel_release_region(base,
205				     region_size);
206err_unreg_drv:
207	platform_driver_unregister(&atml_drv);
208	return rc;
209}
210
211static void __exit cleanup_atmel(void)
212{
213	platform_driver_unregister(&atml_drv);
214	atml_plat_remove();
215}
216
217module_init(init_atmel);
218module_exit(cleanup_atmel);
219
220MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
221MODULE_DESCRIPTION("TPM Driver");
222MODULE_VERSION("2.0");
223MODULE_LICENSE("GPL");
224