linux/drivers/char/tpm/tpm_atmel.c
Gustavo A. R. Silva e4b0852798 tpm/tpm_atmel: remove unnecessary NULL check
Remove unnecessary NULL check.
Pointer _chip_ cannot be NULL in this instance.

Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkine@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkine@linux.intel.com> (compilation)
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2017-06-19 02:36:04 +02:00

241 lines
5.4 KiB
C

/*
* 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
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2 of the
* License.
*
*/
#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 count;
}
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, &region_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");