tpm_atmel.c

  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 "tpm.h"
 18
 19struct tpm_atmel_priv {
 20	int region_size;
 21	int have_region;
 22	unsigned long base;
 23	void __iomem *iobase;
 24};
 25
 26#define atmel_getb(chip, offset) inb(atmel_get_priv(chip)->base + (offset))
 27#define atmel_putb(val, chip, offset) \
 28	outb(val, atmel_get_priv(chip)->base + (offset))
 29#define atmel_request_region request_region
 30#define atmel_release_region release_region
 31/* Atmel definitions */
 32enum tpm_atmel_addr {
 33	TPM_ATMEL_BASE_ADDR_LO = 0x08,
 34	TPM_ATMEL_BASE_ADDR_HI = 0x09
 35};
 36
 37static inline int tpm_read_index(int base, int index)
 38{
 39	outb(index, base);
 40	return inb(base + 1) & 0xFF;
 41}
 42
 43/* Verify this is a 1.1 Atmel TPM */
 44static int atmel_verify_tpm11(void)
 45{
 46	/* verify that it is an Atmel part */
 47	if (tpm_read_index(TPM_ADDR, 4) != 'A' ||
 48	    tpm_read_index(TPM_ADDR, 5) != 'T' ||
 49	    tpm_read_index(TPM_ADDR, 6) != 'M' ||
 50	    tpm_read_index(TPM_ADDR, 7) != 'L')
 51		return 1;
 52
 53	/* query chip for its version number */
 54	if (tpm_read_index(TPM_ADDR, 0x00) != 1 ||
 55	    tpm_read_index(TPM_ADDR, 0x01) != 1)
 56		return 1;
 57
 58	/* This is an atmel supported part */
 59	return 0;
 60}
 61
 62/* Determine where to talk to device */
 63static void __iomem *atmel_get_base_addr(unsigned long *base, int *region_size)
 64{
 65	int lo, hi;
 66
 67	if (atmel_verify_tpm11() != 0)
 68		return NULL;
 69
 70	lo = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_LO);
 71	hi = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_HI);
 72
 73	*base = (hi << 8) | lo;
 74	*region_size = 2;
 75
 76	return ioport_map(*base, *region_size);
 77}
 78
 79/* write status bits */
 80enum tpm_atmel_write_status {
 81	ATML_STATUS_ABORT = 0x01,
 82	ATML_STATUS_LASTBYTE = 0x04
 83};
 84/* read status bits */
 85enum tpm_atmel_read_status {
 86	ATML_STATUS_BUSY = 0x01,
 87	ATML_STATUS_DATA_AVAIL = 0x02,
 88	ATML_STATUS_REWRITE = 0x04,
 89	ATML_STATUS_READY = 0x08
 90};
 91
 92static int tpm_atml_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 93{
 94	struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
 95	u8 status, *hdr = buf;
 96	u32 size;
 97	int i;
 98	__be32 *native_size;
 99
100	/* start reading header */
101	if (count < 6)
102		return -EIO;
103
104	for (i = 0; i < 6; i++) {
105		status = ioread8(priv->iobase + 1);
106		if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
107			dev_err(&chip->dev, "error reading header\n");
108			return -EIO;
109		}
110		*buf++ = ioread8(priv->iobase);
111	}
112
113	/* size of the data received */
114	native_size = (__force __be32 *) (hdr + 2);
115	size = be32_to_cpu(*native_size);
116
117	if (count < size) {
118		dev_err(&chip->dev,
119			"Recv size(%d) less than available space\n", size);
120		for (; i < size; i++) {	/* clear the waiting data anyway */
121			status = ioread8(priv->iobase + 1);
122			if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
123				dev_err(&chip->dev, "error reading data\n");
124				return -EIO;
125			}
126		}
127		return -EIO;
128	}
129
130	/* read all the data available */
131	for (; i < size; i++) {
132		status = ioread8(priv->iobase + 1);
133		if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
134			dev_err(&chip->dev, "error reading data\n");
135			return -EIO;
136		}
137		*buf++ = ioread8(priv->iobase);
138	}
139
140	/* make sure data available is gone */
141	status = ioread8(priv->iobase + 1);
142
143	if (status & ATML_STATUS_DATA_AVAIL) {
144		dev_err(&chip->dev, "data available is stuck\n");
145		return -EIO;
146	}
147
148	return size;
149}
150
151static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t bufsiz,
152			 size_t count)
153{
154	struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
155	int i;
156
157	dev_dbg(&chip->dev, "tpm_atml_send:\n");
158	for (i = 0; i < count; i++) {
159		dev_dbg(&chip->dev, "%d 0x%x(%d)\n",  i, buf[i], buf[i]);
160		iowrite8(buf[i], priv->iobase);
161	}
162
163	return 0;
164}
165
166static void tpm_atml_cancel(struct tpm_chip *chip)
167{
168	struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
169
170	iowrite8(ATML_STATUS_ABORT, priv->iobase + 1);
171}
172
173static u8 tpm_atml_status(struct tpm_chip *chip)
174{
175	struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
176
177	return ioread8(priv->iobase + 1);
178}
179
180static bool tpm_atml_req_canceled(struct tpm_chip *chip, u8 status)
181{
182	return (status == ATML_STATUS_READY);
183}
184
185static const struct tpm_class_ops tpm_atmel = {
186	.recv = tpm_atml_recv,
187	.send = tpm_atml_send,
188	.cancel = tpm_atml_cancel,
189	.status = tpm_atml_status,
190	.req_complete_mask = ATML_STATUS_BUSY | ATML_STATUS_DATA_AVAIL,
191	.req_complete_val = ATML_STATUS_DATA_AVAIL,
192	.req_canceled = tpm_atml_req_canceled,
193};
194
195static struct platform_device *pdev;
196
197static void atml_plat_remove(void)
198{
199	struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
200	struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
201
202	tpm_chip_unregister(chip);
203	if (priv->have_region)
204		atmel_release_region(priv->base, priv->region_size);
205	platform_device_unregister(pdev);
206}
207
208static SIMPLE_DEV_PM_OPS(tpm_atml_pm, tpm_pm_suspend, tpm_pm_resume);
209
210static struct platform_driver atml_drv = {
211	.driver = {
212		.name = "tpm_atmel",
213		.pm		= &tpm_atml_pm,
214	},
215};
216
217static int __init init_atmel(void)
218{
219	int rc = 0;
220	void __iomem *iobase = NULL;
221	int have_region, region_size;
222	unsigned long base;
223	struct  tpm_chip *chip;
224	struct tpm_atmel_priv *priv;
225
226	rc = platform_driver_register(&atml_drv);
227	if (rc)
228		return rc;
229
230	if ((iobase = atmel_get_base_addr(&base, &region_size)) == NULL) {
231		rc = -ENODEV;
232		goto err_unreg_drv;
233	}
234
235	have_region =
236	    (atmel_request_region
237	     (base, region_size, "tpm_atmel0") == NULL) ? 0 : 1;
238
239	pdev = platform_device_register_simple("tpm_atmel", -1, NULL, 0);
240	if (IS_ERR(pdev)) {
241		rc = PTR_ERR(pdev);
242		goto err_rel_reg;
243	}
244
245	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
246	if (!priv) {
247		rc = -ENOMEM;
248		goto err_unreg_dev;
249	}
250
251	priv->iobase = iobase;
252	priv->base = base;
253	priv->have_region = have_region;
254	priv->region_size = region_size;
255
256	chip = tpmm_chip_alloc(&pdev->dev, &tpm_atmel);
257	if (IS_ERR(chip)) {
258		rc = PTR_ERR(chip);
259		goto err_unreg_dev;
260	}
261
262	dev_set_drvdata(&chip->dev, priv);
263
264	rc = tpm_chip_register(chip);
265	if (rc)
266		goto err_unreg_dev;
267
268	return 0;
269
270err_unreg_dev:
271	platform_device_unregister(pdev);
272err_rel_reg:
273	if (have_region)
274		atmel_release_region(base,
275				     region_size);
276err_unreg_drv:
277	platform_driver_unregister(&atml_drv);
278	return rc;
279}
280
281static void __exit cleanup_atmel(void)
282{
283	platform_driver_unregister(&atml_drv);
284	atml_plat_remove();
285}
286
287module_init(init_atmel);
288module_exit(cleanup_atmel);
289
290MODULE_AUTHOR("Leendert van Doorn <leendert@watson.ibm.com>");
291MODULE_DESCRIPTION("TPM Driver");
292MODULE_VERSION("2.0");
293MODULE_LICENSE("GPL");