- 根目录:
- drivers
- char
- tpm
- st33zp24
- st33zp24.c
/*
* STMicroelectronics TPM Linux driver for TPM ST33ZP24
* Copyright (C) 2009 - 2015 STMicroelectronics
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/wait.h>
#include <linux/freezer.h>
#include <linux/string.h>
#include <linux/interrupt.h>
#include <linux/gpio.h>
#include <linux/sched.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/slab.h>
#include "../tpm.h"
#include "st33zp24.h"
#define TPM_ACCESS 0x0
#define TPM_STS 0x18
#define TPM_DATA_FIFO 0x24
#define TPM_INTF_CAPABILITY 0x14
#define TPM_INT_STATUS 0x10
#define TPM_INT_ENABLE 0x08
#define LOCALITY0 0
enum st33zp24_access {
TPM_ACCESS_VALID = 0x80,
TPM_ACCESS_ACTIVE_LOCALITY = 0x20,
TPM_ACCESS_REQUEST_PENDING = 0x04,
TPM_ACCESS_REQUEST_USE = 0x02,
};
enum st33zp24_status {
TPM_STS_VALID = 0x80,
TPM_STS_COMMAND_READY = 0x40,
TPM_STS_GO = 0x20,
TPM_STS_DATA_AVAIL = 0x10,
TPM_STS_DATA_EXPECT = 0x08,
};
enum st33zp24_int_flags {
TPM_GLOBAL_INT_ENABLE = 0x80,
TPM_INTF_CMD_READY_INT = 0x080,
TPM_INTF_FIFO_AVALAIBLE_INT = 0x040,
TPM_INTF_WAKE_UP_READY_INT = 0x020,
TPM_INTF_LOCALITY_CHANGE_INT = 0x004,
TPM_INTF_STS_VALID_INT = 0x002,
TPM_INTF_DATA_AVAIL_INT = 0x001,
};
enum tis_defaults {
TIS_SHORT_TIMEOUT = 750,
TIS_LONG_TIMEOUT = 2000,
};
struct st33zp24_dev {
struct tpm_chip *chip;
void *phy_id;
const struct st33zp24_phy_ops *ops;
u32 intrs;
int io_lpcpd;
};
/*
* clear_interruption clear the pending interrupt.
* @param: tpm_dev, the tpm device device.
* @return: the interrupt status value.
*/
static u8 clear_interruption(struct st33zp24_dev *tpm_dev)
{
u8 interrupt;
tpm_dev->ops->recv(tpm_dev->phy_id, TPM_INT_STATUS, &interrupt, 1);
tpm_dev->ops->send(tpm_dev->phy_id, TPM_INT_STATUS, &interrupt, 1);
return interrupt;
} /* clear_interruption() */
/*
* st33zp24_cancel, cancel the current command execution or
* set STS to COMMAND READY.
* @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h
*/
static void st33zp24_cancel(struct tpm_chip *chip)
{
struct st33zp24_dev *tpm_dev;
u8 data;
tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip);
data = TPM_STS_COMMAND_READY;
tpm_dev->ops->send(tpm_dev->phy_id, TPM_STS, &data, 1);
} /* st33zp24_cancel() */
/*
* st33zp24_status return the TPM_STS register
* @param: chip, the tpm chip description
* @return: the TPM_STS register value.
*/
static u8 st33zp24_status(struct tpm_chip *chip)
{
struct st33zp24_dev *tpm_dev;
u8 data;
tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip);
tpm_dev->ops->recv(tpm_dev->phy_id, TPM_STS, &data, 1);
return data;
} /* st33zp24_status() */
/*
* check_locality if the locality is active
* @param: chip, the tpm chip description
* @return: the active locality or -EACCESS.
*/
static int check_locality(struct tpm_chip *chip)
{
struct st33zp24_dev *tpm_dev;
u8 data;
u8 status;
tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip);
status = tpm_dev->ops->recv(tpm_dev->phy_id, TPM_ACCESS, &data, 1);
if (status && (data &
(TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
(TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID))
return chip->vendor.locality;
return -EACCES;
} /* check_locality() */
/*
* request_locality request the TPM locality
* @param: chip, the chip description
* @return: the active locality or negative value.
*/
static int request_locality(struct tpm_chip *chip)
{
unsigned long stop;
long ret;
struct st33zp24_dev *tpm_dev;
u8 data;
if (check_locality(chip) == chip->vendor.locality)
return chip->vendor.locality;
tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip);
data = TPM_ACCESS_REQUEST_USE;
ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_ACCESS, &data, 1);
if (ret < 0)
return ret;
stop = jiffies + chip->vendor.timeout_a;
/* Request locality is usually effective after the request */
do {
if (check_locality(chip) >= 0)
return chip->vendor.locality;
msleep(TPM_TIMEOUT);
} while (time_before(jiffies, stop));
/* could not get locality */
return -EACCES;
} /* request_locality() */
/*
* release_locality release the active locality
* @param: chip, the tpm chip description.
*/
static void release_locality(struct tpm_chip *chip)
{
struct st33zp24_dev *tpm_dev;
u8 data;
tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip);
data = TPM_ACCESS_ACTIVE_LOCALITY;
tpm_dev->ops->send(tpm_dev->phy_id, TPM_ACCESS, &data, 1);
}
/*
* get_burstcount return the burstcount value
* @param: chip, the chip description
* return: the burstcount or negative value.
*/
static int get_burstcount(struct tpm_chip *chip)
{
unsigned long stop;
int burstcnt, status;
u8 tpm_reg, temp;
struct st33zp24_dev *tpm_dev;
tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip);
stop = jiffies + chip->vendor.timeout_d;
do {
tpm_reg = TPM_STS + 1;
status = tpm_dev->ops->recv(tpm_dev->phy_id, tpm_reg, &temp, 1);
if (status < 0)
return -EBUSY;
tpm_reg = TPM_STS + 2;
burstcnt = temp;
status = tpm_dev->ops->recv(tpm_dev->phy_id, tpm_reg, &temp, 1);
if (status < 0)
return -EBUSY;
burstcnt |= temp << 8;
if (burstcnt)
return burstcnt;
msleep(TPM_TIMEOUT);
} while (time_before(jiffies, stop));
return -EBUSY;
} /* get_burstcount() */
/*
* wait_for_tpm_stat_cond
* @param: chip, chip description
* @param: mask, expected mask value
* @param: check_cancel, does the command expected to be canceled ?
* @param: canceled, did we received a cancel request ?
* @return: true if status == mask or if the command is canceled.
* false in other cases.
*/
static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
bool check_cancel, bool *canceled)
{
u8 status = chip->ops->status(chip);
*canceled = false;
if ((status & mask) == mask)
return true;
if (check_cancel && chip->ops->req_canceled(chip, status)) {
*canceled = true;
return true;
}
return false;
}
/*
* wait_for_stat wait for a TPM_STS value
* @param: chip, the tpm chip description
* @param: mask, the value mask to wait
* @param: timeout, the timeout
* @param: queue, the wait queue.
* @param: check_cancel, does the command can be cancelled ?
* @return: the tpm status, 0 if success, -ETIME if timeout is reached.
*/
static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
wait_queue_head_t *queue, bool check_cancel)
{
unsigned long stop;
int ret = 0;
bool canceled = false;
bool condition;
u32 cur_intrs;
u8 status;
struct st33zp24_dev *tpm_dev;
tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip);
/* check current status */
status = st33zp24_status(chip);
if ((status & mask) == mask)
return 0;
stop = jiffies + timeout;
if (chip->vendor.irq) {
cur_intrs = tpm_dev->intrs;
clear_interruption(tpm_dev);
enable_irq(chip->vendor.irq);
do {
if (ret == -ERESTARTSYS && freezing(current))
clear_thread_flag(TIF_SIGPENDING);
timeout = stop - jiffies;
if ((long) timeout <= 0)
return -1;
ret = wait_event_interruptible_timeout(*queue,
cur_intrs != tpm_dev->intrs,
timeout);
clear_interruption(tpm_dev);
condition = wait_for_tpm_stat_cond(chip, mask,
check_cancel, &canceled);
if (ret >= 0 && condition) {
if (canceled)
return -ECANCELED;
return 0;
}
} while (ret == -ERESTARTSYS && freezing(current));
disable_irq_nosync(chip->vendor.irq);
} else {
do {
msleep(TPM_TIMEOUT);
status = chip->ops->status(chip);
if ((status & mask) == mask)
return 0;
} while (time_before(jiffies, stop));
}
return -ETIME;
} /* wait_for_stat() */
/*
* recv_data receive data
* @param: chip, the tpm chip description
* @param: buf, the buffer where the data are received
* @param: count, the number of data to receive
* @return: the number of bytes read from TPM FIFO.
*/
static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
{
int size = 0, burstcnt, len, ret;
struct st33zp24_dev *tpm_dev;
tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip);
while (size < count &&
wait_for_stat(chip,
TPM_STS_DATA_AVAIL | TPM_STS_VALID,
chip->vendor.timeout_c,
&chip->vendor.read_queue, true) == 0) {
burstcnt = get_burstcount(chip);
if (burstcnt < 0)
return burstcnt;
len = min_t(int, burstcnt, count - size);
ret = tpm_dev->ops->recv(tpm_dev->phy_id, TPM_DATA_FIFO,
buf + size, len);
if (ret < 0)
return ret;
size += len;
}
return size;
}
/*
* tpm_ioserirq_handler the serirq irq handler
* @param: irq, the tpm chip description
* @param: dev_id, the description of the chip
* @return: the status of the handler.
*/
static irqreturn_t tpm_ioserirq_handler(int irq, void *dev_id)
{
struct tpm_chip *chip = dev_id;
struct st33zp24_dev *tpm_dev;
tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip);
tpm_dev->intrs++;
wake_up_interruptible(&chip->vendor.read_queue);
disable_irq_nosync(chip->vendor.irq);
return IRQ_HANDLED;
} /* tpm_ioserirq_handler() */
/*
* st33zp24_send send TPM commands through the I2C bus.
*
* @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h
* @param: buf, the buffer to send.
* @param: count, the number of bytes to send.
* @return: In case of success the number of bytes sent.
* In other case, a < 0 value describing the issue.
*/
static int st33zp24_send(struct tpm_chip *chip, unsigned char *buf,
size_t len)
{
u32 status, i, size, ordinal;
int burstcnt = 0;
int ret;
u8 data;
struct st33zp24_dev *tpm_dev;
if (!chip)
return -EBUSY;
if (len < TPM_HEADER_SIZE)
return -EBUSY;
tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip);
ret = request_locality(chip);
if (ret < 0)
return ret;
status = st33zp24_status(chip);
if ((status & TPM_STS_COMMAND_READY) == 0) {
st33zp24_cancel(chip);
if (wait_for_stat
(chip, TPM_STS_COMMAND_READY, chip->vendor.timeout_b,
&chip->vendor.read_queue, false) < 0) {
ret = -ETIME;
goto out_err;
}
}
for (i = 0; i < len - 1;) {
burstcnt = get_burstcount(chip);
if (burstcnt < 0)
return burstcnt;
size = min_t(int, len - i - 1, burstcnt);
ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_DATA_FIFO,
buf + i, size);
if (ret < 0)
goto out_err;
i += size;
}
status = st33zp24_status(chip);
if ((status & TPM_STS_DATA_EXPECT) == 0) {
ret = -EIO;
goto out_err;
}
ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_DATA_FIFO,
buf + len - 1, 1);
if (ret < 0)
goto out_err;
status = st33zp24_status(chip);
if ((status & TPM_STS_DATA_EXPECT) != 0) {
ret = -EIO;
goto out_err;
}
data = TPM_STS_GO;
ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_STS, &data, 1);
if (ret < 0)
goto out_err;
if (chip->vendor.irq) {
ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
ret = wait_for_stat(chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID,
tpm_calc_ordinal_duration(chip, ordinal),
&chip->vendor.read_queue, false);
if (ret < 0)
goto out_err;
}
return len;
out_err:
st33zp24_cancel(chip);
release_locality(chip);
return ret;
}
/*
* st33zp24_recv received TPM response through TPM phy.
* @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h.
* @param: buf, the buffer to store datas.
* @param: count, the number of bytes to send.
* @return: In case of success the number of bytes received.
* In other case, a < 0 value describing the issue.
*/
static int st33zp24_recv(struct tpm_chip *chip, unsigned char *buf,
size_t count)
{
int size = 0;
int expected;
if (!chip)
return -EBUSY;
if (count < TPM_HEADER_SIZE) {
size = -EIO;
goto out;
}
size = recv_data(chip, buf, TPM_HEADER_SIZE);
if (size < TPM_HEADER_SIZE) {
dev_err(&chip->dev, "Unable to read header\n");
goto out;
}
expected = be32_to_cpu(*(__be32 *)(buf + 2));
if (expected > count) {
size = -EIO;
goto out;
}
size += recv_data(chip, &buf[TPM_HEADER_SIZE],
expected - TPM_HEADER_SIZE);
if (size < expected) {
dev_err(&chip->dev, "Unable to read remainder of result\n");
size = -ETIME;
}
out:
st33zp24_cancel(chip);
release_locality(chip);
return size;
}
/*
* st33zp24_req_canceled
* @param: chip, the tpm_chip description as specified in driver/char/tpm/tpm.h.
* @param: status, the TPM status.
* @return: Does TPM ready to compute a new command ? true.
*/
static bool st33zp24_req_canceled(struct tpm_chip *chip, u8 status)
{
return (status == TPM_STS_COMMAND_READY);
}
static const struct tpm_class_ops st33zp24_tpm = {
.send = st33zp24_send,
.recv = st33zp24_recv,
.cancel = st33zp24_cancel,
.status = st33zp24_status,
.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
.req_canceled = st33zp24_req_canceled,
};
/*
* st33zp24_probe initialize the TPM device
* @param: client, the i2c_client drescription (TPM I2C description).
* @param: id, the i2c_device_id struct.
* @return: 0 in case of success.
* -1 in other case.
*/
int st33zp24_probe(void *phy_id, const struct st33zp24_phy_ops *ops,
struct device *dev, int irq, int io_lpcpd)
{
int ret;
u8 intmask = 0;
struct tpm_chip *chip;
struct st33zp24_dev *tpm_dev;
chip = tpmm_chip_alloc(dev, &st33zp24_tpm);
if (IS_ERR(chip))
return PTR_ERR(chip);
tpm_dev = devm_kzalloc(dev, sizeof(struct st33zp24_dev),
GFP_KERNEL);
if (!tpm_dev)
return -ENOMEM;
TPM_VPRIV(chip) = tpm_dev;
tpm_dev->phy_id = phy_id;
tpm_dev->ops = ops;
chip->vendor.timeout_a = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
chip->vendor.timeout_b = msecs_to_jiffies(TIS_LONG_TIMEOUT);
chip->vendor.timeout_c = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
chip->vendor.timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
chip->vendor.locality = LOCALITY0;
if (irq) {
/* INTERRUPT Setup */
init_waitqueue_head(&chip->vendor.read_queue);
tpm_dev->intrs = 0;
if (request_locality(chip) != LOCALITY0) {
ret = -ENODEV;
goto _tpm_clean_answer;
}
clear_interruption(tpm_dev);
ret = devm_request_irq(dev, irq, tpm_ioserirq_handler,
IRQF_TRIGGER_HIGH, "TPM SERIRQ management",
chip);
if (ret < 0) {
dev_err(&chip->dev, "TPM SERIRQ signals %d not available\n",
irq);
goto _tpm_clean_answer;
}
intmask |= TPM_INTF_CMD_READY_INT
| TPM_INTF_STS_VALID_INT
| TPM_INTF_DATA_AVAIL_INT;
ret = tpm_dev->ops->send(tpm_dev->phy_id, TPM_INT_ENABLE,
&intmask, 1);
if (ret < 0)
goto _tpm_clean_answer;
intmask = TPM_GLOBAL_INT_ENABLE;
ret = tpm_dev->ops->send(tpm_dev->phy_id, (TPM_INT_ENABLE + 3),
&intmask, 1);
if (ret < 0)
goto _tpm_clean_answer;
chip->vendor.irq = irq;
disable_irq_nosync(chip->vendor.irq);
tpm_gen_interrupt(chip);
}
tpm_get_timeouts(chip);
tpm_do_selftest(chip);
return tpm_chip_register(chip);
_tpm_clean_answer:
dev_info(&chip->dev, "TPM initialization fail\n");
return ret;
}
EXPORT_SYMBOL(st33zp24_probe);
/*
* st33zp24_remove remove the TPM device
* @param: tpm_data, the tpm phy.
* @return: 0 in case of success.
*/
int st33zp24_remove(struct tpm_chip *chip)
{
tpm_chip_unregister(chip);
return 0;
}
EXPORT_SYMBOL(st33zp24_remove);
#ifdef CONFIG_PM_SLEEP
/*
* st33zp24_pm_suspend suspend the TPM device
* @param: tpm_data, the tpm phy.
* @param: mesg, the power management message.
* @return: 0 in case of success.
*/
int st33zp24_pm_suspend(struct device *dev)
{
struct tpm_chip *chip = dev_get_drvdata(dev);
struct st33zp24_dev *tpm_dev;
int ret = 0;
tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip);
if (gpio_is_valid(tpm_dev->io_lpcpd))
gpio_set_value(tpm_dev->io_lpcpd, 0);
else
ret = tpm_pm_suspend(dev);
return ret;
} /* st33zp24_pm_suspend() */
EXPORT_SYMBOL(st33zp24_pm_suspend);
/*
* st33zp24_pm_resume resume the TPM device
* @param: tpm_data, the tpm phy.
* @return: 0 in case of success.
*/
int st33zp24_pm_resume(struct device *dev)
{
struct tpm_chip *chip = dev_get_drvdata(dev);
struct st33zp24_dev *tpm_dev;
int ret = 0;
tpm_dev = (struct st33zp24_dev *)TPM_VPRIV(chip);
if (gpio_is_valid(tpm_dev->io_lpcpd)) {
gpio_set_value(tpm_dev->io_lpcpd, 1);
ret = wait_for_stat(chip,
TPM_STS_VALID, chip->vendor.timeout_b,
&chip->vendor.read_queue, false);
} else {
ret = tpm_pm_resume(dev);
if (!ret)
tpm_do_selftest(chip);
}
return ret;
} /* st33zp24_pm_resume() */
EXPORT_SYMBOL(st33zp24_pm_resume);
#endif
MODULE_AUTHOR("TPM support (TPMsupport@list.st.com)");
MODULE_DESCRIPTION("ST33ZP24 TPM 1.2 driver");
MODULE_VERSION("1.3.0");
MODULE_LICENSE("GPL");