char/tpm/tpm_atmel.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (C) 2004 IBM Corporation
0004  *
0005  * Authors:
0006  * Leendert van Doorn <leendert@watson.ibm.com>
0007  * Dave Safford <safford@watson.ibm.com>
0008  * Reiner Sailer <sailer@watson.ibm.com>
0009  * Kylene Hall <kjhall@us.ibm.com>
0010  *
0011  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
0012  *
0013  * Device driver for TCG/TCPA TPM (trusted platform module).
0014  * Specifications at www.trustedcomputinggroup.org
0015  */
0016
0017 #include "tpm.h"
0018 #include "tpm_atmel.h"
0019
0020 /* write status bits */
0021 enum tpm_atmel_write_status {
0022     ATML_STATUS_ABORT = 0x01,
0023     ATML_STATUS_LASTBYTE = 0x04
0024 };
0025 /* read status bits */
0026 enum tpm_atmel_read_status {
0027     ATML_STATUS_BUSY = 0x01,
0028     ATML_STATUS_DATA_AVAIL = 0x02,
0029     ATML_STATUS_REWRITE = 0x04,
0030     ATML_STATUS_READY = 0x08
0031 };
0032
0033 static int tpm_atml_recv(struct tpm_chip *chip, u8 *buf, size_t count)
0034 {
0035     struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
0036     u8 status, *hdr = buf;
0037     u32 size;
0038     int i;
0039     __be32 *native_size;
0040
0041     /* start reading header */
0042     if (count < 6)
0043         return -EIO;
0044
0045     for (i = 0; i < 6; i++) {
0046         status = ioread8(priv->iobase + 1);
0047         if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
0048             dev_err(&chip->dev, "error reading header\n");
0049             return -EIO;
0050         }
0051         *buf++ = ioread8(priv->iobase);
0052     }
0053
0054     /* size of the data received */
0055     native_size = (__force __be32 *) (hdr + 2);
0056     size = be32_to_cpu(*native_size);
0057
0058     if (count < size) {
0059         dev_err(&chip->dev,
0060             "Recv size(%d) less than available space\n", size);
0061         for (; i < size; i++) { /* clear the waiting data anyway */
0062             status = ioread8(priv->iobase + 1);
0063             if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
0064                 dev_err(&chip->dev, "error reading data\n");
0065                 return -EIO;
0066             }
0067         }
0068         return -EIO;
0069     }
0070
0071     /* read all the data available */
0072     for (; i < size; i++) {
0073         status = ioread8(priv->iobase + 1);
0074         if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
0075             dev_err(&chip->dev, "error reading data\n");
0076             return -EIO;
0077         }
0078         *buf++ = ioread8(priv->iobase);
0079     }
0080
0081     /* make sure data available is gone */
0082     status = ioread8(priv->iobase + 1);
0083
0084     if (status & ATML_STATUS_DATA_AVAIL) {
0085         dev_err(&chip->dev, "data available is stuck\n");
0086         return -EIO;
0087     }
0088
0089     return size;
0090 }
0091
0092 static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t count)
0093 {
0094     struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
0095     int i;
0096
0097     dev_dbg(&chip->dev, "tpm_atml_send:\n");
0098     for (i = 0; i < count; i++) {
0099         dev_dbg(&chip->dev, "%d 0x%x(%d)\n",  i, buf[i], buf[i]);
0100         iowrite8(buf[i], priv->iobase);
0101     }
0102
0103     return 0;
0104 }
0105
0106 static void tpm_atml_cancel(struct tpm_chip *chip)
0107 {
0108     struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
0109
0110     iowrite8(ATML_STATUS_ABORT, priv->iobase + 1);
0111 }
0112
0113 static u8 tpm_atml_status(struct tpm_chip *chip)
0114 {
0115     struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
0116
0117     return ioread8(priv->iobase + 1);
0118 }
0119
0120 static bool tpm_atml_req_canceled(struct tpm_chip *chip, u8 status)
0121 {
0122     return (status == ATML_STATUS_READY);
0123 }
0124
0125 static const struct tpm_class_ops tpm_atmel = {
0126     .recv = tpm_atml_recv,
0127     .send = tpm_atml_send,
0128     .cancel = tpm_atml_cancel,
0129     .status = tpm_atml_status,
0130     .req_complete_mask = ATML_STATUS_BUSY | ATML_STATUS_DATA_AVAIL,
0131     .req_complete_val = ATML_STATUS_DATA_AVAIL,
0132     .req_canceled = tpm_atml_req_canceled,
0133 };
0134
0135 static struct platform_device *pdev;
0136
0137 static void atml_plat_remove(void)
0138 {
0139     struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
0140     struct tpm_atmel_priv *priv = dev_get_drvdata(&chip->dev);
0141
0142     tpm_chip_unregister(chip);
0143     if (priv->have_region)
0144         atmel_release_region(priv->base, priv->region_size);
0145     atmel_put_base_addr(priv->iobase);
0146     platform_device_unregister(pdev);
0147 }
0148
0149 static SIMPLE_DEV_PM_OPS(tpm_atml_pm, tpm_pm_suspend, tpm_pm_resume);
0150
0151 static struct platform_driver atml_drv = {
0152     .driver = {
0153         .name = "tpm_atmel",
0154         .pm     = &tpm_atml_pm,
0155     },
0156 };
0157
0158 static int __init init_atmel(void)
0159 {
0160     int rc = 0;
0161     void __iomem *iobase = NULL;
0162     int have_region, region_size;
0163     unsigned long base;
0164     struct  tpm_chip *chip;
0165     struct tpm_atmel_priv *priv;
0166
0167     rc = platform_driver_register(&atml_drv);
0168     if (rc)
0169         return rc;
0170
0171     if ((iobase = atmel_get_base_addr(&base, &region_size)) == NULL) {
0172         rc = -ENODEV;
0173         goto err_unreg_drv;
0174     }
0175
0176     have_region =
0177         (atmel_request_region
0178          (base, region_size, "tpm_atmel0") == NULL) ? 0 : 1;
0179
0180     pdev = platform_device_register_simple("tpm_atmel", -1, NULL, 0);
0181     if (IS_ERR(pdev)) {
0182         rc = PTR_ERR(pdev);
0183         goto err_rel_reg;
0184     }
0185
0186     priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
0187     if (!priv) {
0188         rc = -ENOMEM;
0189         goto err_unreg_dev;
0190     }
0191
0192     priv->iobase = iobase;
0193     priv->base = base;
0194     priv->have_region = have_region;
0195     priv->region_size = region_size;
0196
0197     chip = tpmm_chip_alloc(&pdev->dev, &tpm_atmel);
0198     if (IS_ERR(chip)) {
0199         rc = PTR_ERR(chip);
0200         goto err_unreg_dev;
0201     }
0202
0203     dev_set_drvdata(&chip->dev, priv);
0204
0205     rc = tpm_chip_register(chip);
0206     if (rc)
0207         goto err_unreg_dev;
0208
0209     return 0;
0210
0211 err_unreg_dev:
0212     platform_device_unregister(pdev);
0213 err_rel_reg:
0214     atmel_put_base_addr(iobase);
0215     if (have_region)
0216         atmel_release_region(base,
0217                      region_size);
0218 err_unreg_drv:
0219     platform_driver_unregister(&atml_drv);
0220     return rc;
0221 }
0222
0223 static void __exit cleanup_atmel(void)
0224 {
0225     platform_driver_unregister(&atml_drv);
0226     atml_plat_remove();
0227 }
0228
0229 module_init(init_atmel);
0230 module_exit(cleanup_atmel);
0231
0232 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
0233 MODULE_DESCRIPTION("TPM Driver");
0234 MODULE_VERSION("2.0");
0235 MODULE_LICENSE("GPL");