Linux-libre 4.13.7-gnu
[librecmc/linux-libre.git] / drivers / char / tpm / tpm_atmel.c
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 */
26 enum tpm_atmel_write_status {
27         ATML_STATUS_ABORT = 0x01,
28         ATML_STATUS_LASTBYTE = 0x04
29 };
30 /* read status bits */
31 enum 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
38 static int tpm_atml_recv(struct tpm_chip *chip, u8 *buf, size_t count)
39 {
40         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
41         u8 status, *hdr = buf;
42         u32 size;
43         int i;
44         __be32 *native_size;
45
46         /* start reading header */
47         if (count < 6)
48                 return -EIO;
49
50         for (i = 0; i < 6; i++) {
51                 status = ioread8(priv->iobase + 1);
52                 if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
53                         dev_err(&chip->dev, "error reading header\n");
54                         return -EIO;
55                 }
56                 *buf++ = ioread8(priv->iobase);
57         }
58
59         /* size of the data received */
60         native_size = (__force __be32 *) (hdr + 2);
61         size = be32_to_cpu(*native_size);
62
63         if (count < size) {
64                 dev_err(&chip->dev,
65                         "Recv size(%d) less than available space\n", size);
66                 for (; i < size; i++) { /* clear the waiting data anyway */
67                         status = ioread8(priv->iobase + 1);
68                         if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
69                                 dev_err(&chip->dev, "error reading data\n");
70                                 return -EIO;
71                         }
72                 }
73                 return -EIO;
74         }
75
76         /* read all the data available */
77         for (; i < size; i++) {
78                 status = ioread8(priv->iobase + 1);
79                 if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
80                         dev_err(&chip->dev, "error reading data\n");
81                         return -EIO;
82                 }
83                 *buf++ = ioread8(priv->iobase);
84         }
85
86         /* make sure data available is gone */
87         status = ioread8(priv->iobase + 1);
88
89         if (status & ATML_STATUS_DATA_AVAIL) {
90                 dev_err(&chip->dev, "data available is stuck\n");
91                 return -EIO;
92         }
93
94         return size;
95 }
96
97 static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t count)
98 {
99         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
100         int i;
101
102         dev_dbg(&chip->dev, "tpm_atml_send:\n");
103         for (i = 0; i < count; i++) {
104                 dev_dbg(&chip->dev, "%d 0x%x(%d)\n",  i, buf[i], buf[i]);
105                 iowrite8(buf[i], priv->iobase);
106         }
107
108         return count;
109 }
110
111 static void tpm_atml_cancel(struct tpm_chip *chip)
112 {
113         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
114
115         iowrite8(ATML_STATUS_ABORT, priv->iobase + 1);
116 }
117
118 static u8 tpm_atml_status(struct tpm_chip *chip)
119 {
120         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
121
122         return ioread8(priv->iobase + 1);
123 }
124
125 static bool tpm_atml_req_canceled(struct tpm_chip *chip, u8 status)
126 {
127         return (status == ATML_STATUS_READY);
128 }
129
130 static const struct tpm_class_ops tpm_atmel = {
131         .recv = tpm_atml_recv,
132         .send = tpm_atml_send,
133         .cancel = tpm_atml_cancel,
134         .status = tpm_atml_status,
135         .req_complete_mask = ATML_STATUS_BUSY | ATML_STATUS_DATA_AVAIL,
136         .req_complete_val = ATML_STATUS_DATA_AVAIL,
137         .req_canceled = tpm_atml_req_canceled,
138 };
139
140 static struct platform_device *pdev;
141
142 static void atml_plat_remove(void)
143 {
144         struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
145         struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
146
147         tpm_chip_unregister(chip);
148         if (priv->have_region)
149                 atmel_release_region(priv->base, priv->region_size);
150         atmel_put_base_addr(priv->iobase);
151         platform_device_unregister(pdev);
152 }
153
154 static SIMPLE_DEV_PM_OPS(tpm_atml_pm, tpm_pm_suspend, tpm_pm_resume);
155
156 static struct platform_driver atml_drv = {
157         .driver = {
158                 .name = "tpm_atmel",
159                 .pm             = &tpm_atml_pm,
160         },
161 };
162
163 static int __init init_atmel(void)
164 {
165         int rc = 0;
166         void __iomem *iobase = NULL;
167         int have_region, region_size;
168         unsigned long base;
169         struct  tpm_chip *chip;
170         struct tpm_atmel_priv *priv;
171
172         rc = platform_driver_register(&atml_drv);
173         if (rc)
174                 return rc;
175
176         if ((iobase = atmel_get_base_addr(&base, &region_size)) == NULL) {
177                 rc = -ENODEV;
178                 goto err_unreg_drv;
179         }
180
181         have_region =
182             (atmel_request_region
183              (base, region_size, "tpm_atmel0") == NULL) ? 0 : 1;
184
185         pdev = platform_device_register_simple("tpm_atmel", -1, NULL, 0);
186         if (IS_ERR(pdev)) {
187                 rc = PTR_ERR(pdev);
188                 goto err_rel_reg;
189         }
190
191         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
192         if (!priv) {
193                 rc = -ENOMEM;
194                 goto err_unreg_dev;
195         }
196
197         priv->iobase = iobase;
198         priv->base = base;
199         priv->have_region = have_region;
200         priv->region_size = region_size;
201
202         chip = tpmm_chip_alloc(&pdev->dev, &tpm_atmel);
203         if (IS_ERR(chip)) {
204                 rc = PTR_ERR(chip);
205                 goto err_unreg_dev;
206         }
207
208         dev_set_drvdata(&chip->dev, priv);
209
210         rc = tpm_chip_register(chip);
211         if (rc)
212                 goto err_unreg_dev;
213
214         return 0;
215
216 err_unreg_dev:
217         platform_device_unregister(pdev);
218 err_rel_reg:
219         atmel_put_base_addr(iobase);
220         if (have_region)
221                 atmel_release_region(base,
222                                      region_size);
223 err_unreg_drv:
224         platform_driver_unregister(&atml_drv);
225         return rc;
226 }
227
228 static void __exit cleanup_atmel(void)
229 {
230         platform_driver_unregister(&atml_drv);
231         atml_plat_remove();
232 }
233
234 module_init(init_atmel);
235 module_exit(cleanup_atmel);
236
237 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
238 MODULE_DESCRIPTION("TPM Driver");
239 MODULE_VERSION("2.0");
240 MODULE_LICENSE("GPL");