diff options
Diffstat (limited to 'drivers/char/tpm/tpm_atmel.c')
| -rw-r--r-- | drivers/char/tpm/tpm_atmel.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm_atmel.c b/drivers/char/tpm/tpm_atmel.c new file mode 100644 index 000000000..54a6750a6 --- /dev/null +++ b/drivers/char/tpm/tpm_atmel.c @@ -0,0 +1,235 @@ +// 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, ®ion_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"); |