// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2020 Google Inc.
*
* Based on Infineon TPM driver by Peter Huewe.
*
* cr50 is a firmware for H1 secure modules that requires special
* handling for the I2C interface.
*
* - Use an interrupt for transaction status instead of hardcoded delays.
* - Must use write+wait+read read protocol.
* - All 4 bytes of status register must be read/written at once.
* - Burst count max is 63 bytes, and burst count behaves slightly differently
* than other I2C TPMs.
* - When reading from FIFO the full burstcnt must be read instead of just
* reading header and determining the remainder.
*/
#include <linux/acpi.h>
#include <linux/completion.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/wait.h>
#include "tpm_tis_core.h"
#define TPM_CR50_MAX_BUFSIZE 64
#define TPM_CR50_TIMEOUT_SHORT_MS 2 /* Short timeout during transactions */
#define TPM_CR50_TIMEOUT_NOIRQ_MS 20 /* Timeout for TPM ready without IRQ */
#define TPM_CR50_I2C_DID_VID 0x00281ae0L /* Device and vendor ID reg value */
#define TPM_TI50_I2C_DID_VID 0x504a6666L /* Device and vendor ID reg value */
#define TPM_CR50_I2C_MAX_RETRIES 3 /* Max retries due to I2C errors */
#define TPM_CR50_I2C_RETRY_DELAY_LO 55 /* Min usecs between retries on I2C */
#define TPM_CR50_I2C_RETRY_DELAY_HI 65 /* Max usecs between retries on I2C */
#define TPM_I2C_ACCESS(l) (0x0000 | ((l) << 4))
#define TPM_I2C_STS(l) (0x0001 | ((l) << 4))
#define TPM_I2C_DATA_FIFO(l) (0x0005 | ((l) << 4))
#define TPM_I2C_DID_VID(l) (0x0006 | ((l) << 4))
/**
* struct tpm_i2c_cr50_priv_data - Driver private data.
* @irq: Irq number used for this chip.
* If irq <= 0, then a fixed timeout is used instead of waiting for irq.
* @tpm_ready: Struct used by irq handler to signal R/W readiness.
* @buf: Buffer used for i2c writes, with i2c address prepended to content.
*
* Private driver struct used by kernel threads and interrupt context.
*/
struct tpm_i2c_cr50_priv_data {
int irq;
struct completion tpm_ready;
u8 buf[TPM_CR50_MAX_BUFSIZE];
};
/**
* tpm_cr50_i2c_int_handler() - cr50 interrupt handler.
* @dummy: Unused parameter.
* @tpm_info: TPM chip information.
*
* The cr50 interrupt handler signals waiting threads that the
* interrupt has been asserted. It does not do any interrupt triggered
* processing but is instead used to avoid fixed delays.
*
* Return:
* IRQ_HANDLED signifies irq was handled by this device.
*/
static irqreturn_t tpm_cr50_i2c_int_handler(int dummy, void *tpm_info)
{
struct tpm_chip *chip = tpm_info;
struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);
complete(&priv->tpm_ready);
return IRQ_HANDLED;
}
/**
* tpm_cr50_i2c_wait_tpm_ready() - Wait for tpm to signal ready.
* @chip: A TPM chip.
*
* Wait for completion interrupt if available, otherwise use a fixed
* delay for the TPM to be ready.
*
* Return:
* - 0: Success.
* - -errno: A POSIX error code.
*/
static int tpm_cr50_i2c_wait_tpm_ready(struct tpm_chip *chip)
{
struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);
/* Use a safe fixed delay if interrupt is not supported */
if (priv->irq <= 0) {
msleep(TPM_CR50_TIMEOUT_NOIRQ_MS);
return 0;
}
/* Wait for interrupt to indicate TPM is ready to respond */
if (!wait_for_completion_timeout(&priv->tpm_ready, chip->timeout_a)) {
dev_warn(&chip->dev, "Timeout waiting for TPM ready\n");
return -ETIMEDOUT;
}
return 0;
}
/**
* tpm_cr50_i2c_enable_tpm_irq() - Enable TPM irq.
* @chip: A TPM chip.
*/
static void tpm_cr50_i2c_enable_tpm_irq(struct tpm_chip *chip)
{
struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);
if (priv->irq > 0) {
reinit_completion(&priv->tpm_ready);
enable_irq(priv->irq);
}
}
/**
* tpm_cr50_i2c_disable_tpm_irq() - Disable TPM irq.
* @chip: A TPM chip.
*/
static void tpm_cr50_i2c_disable_tpm_irq(struct tpm_chip *chip)
{
struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);
if (priv->irq > 0)
disable_irq(priv->irq);
}
/**
* tpm_cr50_i2c_transfer_message() - Transfer a message over i2c.
* @dev: Device information.
* @adapter: I2C adapter.
* @msg: Message to transfer.
*
* Call unlocked i2c transfer routine with the provided parameters and
* retry in case of bus errors.
*
* Return:
* - 0: Success.
* - -errno: A POSIX error code.
*/
static int tpm_cr50_i2c_transfer_message(struct device *dev,
struct i2c_adapter *adapter,
struct i2c_msg *msg)
{
unsigned int try;
int rc;
for (try = 0; try < TPM_CR50_I2C_MAX_RETRIES; try++) {
rc = __i2c_transfer(adapter, msg, 1);
if (rc == 1)
return 0; /* Successfully transferred the message */
if (try)
dev_warn(dev, "i2c transfer failed (attempt %d/%d): %d\n",
try + 1, TPM_CR50_I2C_MAX_RETRIES, rc);
usleep_range(TPM_CR50_I2C_RETRY_DELAY_LO, TPM_CR50_I2C_RETRY_DELAY_HI);
}
/* No i2c message transferred */
return -EIO;
}
/**
* tpm_cr50_i2c_read() - Read from TPM register.
* @chip: A TPM chip.
* @addr: Register address to read from.
* @buffer: Read destination, provided by caller.
* @len: Number of bytes to read.
*
* Sends the register address byte to the TPM, then waits until TPM
* is ready via interrupt signal or timeout expiration, then 'len'
* bytes are read from TPM response into the provided 'buffer'.
*
* Return:
* - 0: Success.
* - -errno: A POSIX error code.
*/
static int tpm_cr50_i2c_read(struct tpm_chip *chip, u8 addr, u8 *buffer, size_t len)
{
struct i2c_client *client = to_i2c_client(chip->dev.parent);
struct i2c_msg msg_reg_addr = {
.addr = client->addr,
.len = 1,
.buf = &addr
};
struct i2c_msg msg_response = {
.addr = client->addr,
.flags = I2C_M_RD,
.len = len,
.buf = buffer
};
int rc;
i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
/* Prepare for completion interrupt */
tpm_cr50_i2c_enable_tpm_irq(chip);
/* Send the register address byte to the TPM */
rc = tpm_cr50_i2c_transfer_message(&chip->dev, client->adapter, &msg_reg_addr);
if (rc < 0)
goto out;
/* Wait for TPM to be ready with response data */
rc = tpm_cr50_i2c_wait_tpm_ready(chip);
if (rc < 0)
goto out;
/* Read response data from the TPM */
rc = tpm_cr50_i2c_transfer_message(&chip->dev, client->adapter, &msg_response);
out:
tpm_cr50_i2c_disable_tpm_irq(chip);
i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
if (rc < 0)
return rc;
return 0;
}
/**
* tpm_cr50_i2c_write()- Write to TPM register.
* @chip: A TPM chip.
* @addr: Register address to write to.
* @buffer: Data to write.
* @len: Number of bytes to write.
*
* The provided address is prepended to the data in 'buffer', the
* combined address+data is sent to the TPM, then wait for TPM to
* indicate it is done writing.
*
* Return:
* - 0: Success.
* - -errno: A POSIX error code.
*/
static int tpm_cr50_i2c_write(struct tpm_chip *chip, u8 addr, u8 *buffer,
size_t len)
{
struct tpm_i2c_cr50_priv_data *priv = dev_get_drvdata(&chip->dev);
struct i2c_client *client = to_i2c_client(chip->dev.parent);
struct i2c_msg msg = {
.addr = client->addr,
.len = len + 1,
.buf = priv->buf
};
int rc;
if (len > TPM_CR50_MAX_BUFSIZE - 1)
return -EINVAL;
/* Prepend the 'register address' to the buffer */
priv->buf[0] = addr;
memcpy(priv->buf + 1, buffer, len);
i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
/* Prepare for completion interrupt */
tpm_cr50_i2c_enable_tpm_irq(chip);
/* Send write request buffer with address */
rc = tpm_cr50_i2c_transfer_message(&chip->dev, client->adapter, &msg);
if (rc < 0)
goto out;
/* Wait for TPM to be ready, ignore timeout */
tpm_cr50_i2c_wait_tpm_ready(chip);
out:
tpm_cr50_i2c_disable_tpm_irq(chip);
i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
if (rc < 0)
return rc;
return 0;
}
/**
* tpm_cr50_check_locality() - Verify TPM locality 0 is active.
* @chip: A TPM chip.
*
* Return:
* - 0: Success.
* - -errno: A POSIX error code.
*/
static int tpm_cr50_check_locality(struct tpm_chip *chip)
{
u8 mask = TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY;
u8 buf;
int rc;
rc = tpm_cr50_i2c_read(chip, TPM_I2C_ACCESS(0), &buf, sizeof(buf));
if (rc < 0)
return rc;
if ((buf & mask) == mask)
return 0;
return -EIO;
}
/**
* tpm_cr50_release_locality() - Release TPM locality.
* @chip: A TPM chip.
* @force: Flag to force release if set.
*/
static void tpm_cr50_release_locality(struct tpm_chip *chip, bool force)
{
u8 mask = TPM_ACCESS_VALID | TPM_ACCESS_REQUEST_PENDING;
u8 addr = TPM_I2C_ACCESS(0);
u8 buf;
if (tpm_cr50_i2c_read(chip, addr, &buf, sizeof(buf)) < 0)
return;
if (force || (buf & mask) == mask) {
buf = TPM_ACCESS_ACTIVE_LOCALITY;
tpm_cr50_i2c_write(chip, addr, &buf, sizeof(buf));
}
}
/**
* tpm_cr50_request_locality() - Request TPM locality 0.
* @chip: A TPM chip.
*
* Return:
* - 0: Success.
* - -errno: A POSIX error code.
*/
static int tpm_cr50_request_locality(struct tpm_chip *chip)
{
u8 buf = TPM_ACCESS_REQUEST_USE;
unsigned long stop;
int rc;
if (!tpm_cr50_check_locality(chip))
return 0;
rc = tpm_cr50_i2c_write(chip, TPM_I2C_ACCESS(0), &buf, sizeof(buf));
if (rc < 0)
return rc;
stop = jiffies + chip->timeout_a;
do {
if (!tpm_cr50_check_locality(chip))
return 0;
msleep(TPM_CR50_TIMEOUT_SHORT_MS);
} while (time_before(jiffies, stop));
return -ETIMEDOUT;
}
/**
* tpm_cr50_i2c_tis_status() - Read cr50 tis status.
* @chip: A TPM chip.
*
* cr50 requires all 4 bytes of status register to be read.
*
* Return:
* TPM status byte.
*/
static u8 tpm_cr50_i2c_tis_status(struct tpm_chip *chip)
{
u8 buf[4];
if (tpm_cr50_i2c_read(chip, TPM_I2C_STS(0), buf, sizeof(buf)) < 0)
return 0;
return buf[0];
}
/**
* tpm_cr50_i2c_tis_set_ready() - Set status register to ready.
* @chip: A TPM chip.
*
* cr50 requires all 4 bytes of status register to be written.
*/
static void tpm_cr50_i2c_tis_set_ready(struct tpm_chip *chip)
{
u8 buf[4] = { TPM_STS_COMMAND_READY };
tpm_cr50_i2c_write(chip, TPM_I2C_STS(0), buf, sizeof(buf));
msleep(TPM_CR50_TIMEOUT_SHORT_MS);
}
/**
* tpm_cr50_i2c_get_burst_and_status() - Get burst count and status.
* @chip: A TPM chip.
* @mask: Status mask.
* @burst: Return value for burst.
* @status: Return value for status.
*
* cr50 uses bytes 3:2 of status register for burst count and
* all 4 bytes must be read.
*
* Return:
* - 0: Success.
* - -errno: A POSIX error code.
*/
static int tpm_cr50_i2c_get_burst_and_status(struct tpm_chip *chip, u8 mask,
size_t *burst, u32 *status)
{
unsigned long stop;
u8 buf[4];
*status = 0;
/* wait for burstcount */
stop = jiffies + chip->timeout_b;
do {
if (tpm_cr50_i2c_read(chip, TPM_I2C_STS(0), buf, sizeof(buf)) < 0) {
msleep(TPM_CR50_TIMEOUT_SHORT_MS);
continue;
}
*status = *buf;
*burst = le16_to_cpup((__le16 *)(buf + 1));
if ((*status & mask) == mask &&
*burst > 0 && *burst <= TPM_CR50_MAX_BUFSIZE - 1)
return 0;
msleep(TPM_CR50_TIMEOUT_SHORT_MS);
} while (time_before(jiffies, stop));
dev_err(&chip->dev, "Timeout reading burst and status\n");
return -ETIMEDOUT;
}
/**
* tpm_cr50_i2c_tis_recv() - TPM reception callback.
* @chip: A TPM chip.
* @buf: Reception buffer.
* @buf_len: Buffer length to read.
*
* Return:
* - >= 0: Number of read bytes.
* - -errno: A POSIX error code.
*/
static int tpm_cr50_i2c_tis_recv(struct tpm_chip *chip, u8 *buf, size_t buf_len)
{
u8 mask = TPM_STS_VALID | TPM_STS_DATA_AVAIL;
size_t burstcnt, cur, len, expected;
u8 addr = TPM_I2C_DATA_FIFO(0);
u32 status;
int rc;
if (buf_len < TPM_HEADER_SIZE)
return -EINVAL;
rc = tpm_cr50_i2c_get_burst_and_status(chip, mask, &burstcnt, &status);
if (rc < 0)
goto out_err;
if (burstcnt > buf_len || burstcnt < TPM_HEADER_SIZE) {
dev_err(&chip->dev,
"Unexpected burstcnt: %zu (max=%zu, min=%d)\n",
burstcnt, buf_len, TPM_HEADER_SIZE);
rc = -EIO;
goto out_err;
}
/* Read first chunk of burstcnt bytes */
rc = tpm_cr50_i2c_read(chip, addr, buf, burstcnt);
if (rc < 0) {
dev_err(&chip->dev, "Read of first chunk failed\n");
goto out_err;
}
/* Determine expected data in the return buffer */
expected = be32_to_cpup((__be32 *)(buf + 2));
if (expected > buf_len) {
dev_err(&chip->dev, "Buffer too small to receive i2c data\n");
rc = -E2BIG;
goto out_err;
}
/* Now read the rest of the data */
cur = burstcnt;
while (cur < expected) {
/* Read updated burst count and check status */
rc = tpm_cr50_i2c_get_burst_and_status(chip, mask, &burstcnt, &status);
if (rc < 0)
goto out_err;
len = min_t(size_t, burstcnt, expected - cur);
rc = tpm_cr50_i2c_read(chip, addr, buf + cur, len);
if (rc < 0) {
dev_err(&chip->dev, "Read failed\n");
goto out_err;
}
cur += len;
}
/* Ensure TPM is done reading data */
rc = tpm_cr50_i2c_get_burst_and_status(chip, TPM_STS_VALID, &burstcnt, &status);
if (rc < 0)
goto out_err;
if (status & TPM_STS_DATA_AVAIL) {
dev_err(&chip->dev, "Data still available\n");
rc = -EIO;
goto out_err;
}
tpm_cr50_release_locality(chip, false);
return cur;
out_err:
/* Abort current transaction if still pending */
if (tpm_cr50_i2c_tis_status(chip) & TPM_STS_COMMAND_READY)
tpm_cr50_i2c_tis_set_ready(chip);
tpm_cr50_release_locality(chip, false);
return rc;
}
/**
* tpm_cr50_i2c_tis_send() - TPM transmission callback.
* @chip: A TPM chip.
* @buf: Buffer to send.
* @len: Buffer length.
*
* Return:
* - 0: Success.
* - -errno: A POSIX error code.
*/
static int tpm_cr50_i2c_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
{
size_t burstcnt, limit, sent = 0;
u8 tpm_go[4] = { TPM_STS_GO };
unsigned long stop;
u32 status;
int rc;
rc = tpm_cr50_request_locality(chip);
if (rc < 0)
return rc;
/* Wait until TPM is ready for a command */
stop = jiffies + chip->timeout_b;
while (!(tpm_cr50_i2c_tis_status(chip) & TPM_STS_COMMAND_READY)) {
if (time_after(jiffies, stop)) {
rc = -ETIMEDOUT;
goto out_err;
}
tpm_cr50_i2c_tis_set_ready(chip);
}
while (len > 0) {
u8 mask = TPM_STS_VALID;
/* Wait for data if this is not the first chunk */
if (sent > 0)
mask |= TPM_STS_DATA_EXPECT;
/* Read burst count and check status */
rc = tpm_cr50_i2c_get_burst_and_status(chip, mask, &burstcnt, &status);
if (rc < 0)
goto out_err;
/*
* Use burstcnt - 1 to account for the address byte
* that is inserted by tpm_cr50_i2c_write()
*/
limit = min_t(size_t, burstcnt - 1, len);
rc = tpm_cr50_i2c_write(chip, TPM_I2C_DATA_FIFO(0), &buf[sent], limit);
if (rc < 0) {
dev_err(&chip->dev, "Write failed\n");
goto out_err;
}
sent += limit;
len -= limit;
}
/* Ensure TPM is not expecting more data */
rc = tpm_cr50_i2c_get_burst_and_status(chip, TPM_STS_VALID, &burstcnt, &status);
if (rc < 0)
goto out_err;
if (status & TPM_STS_DATA_EXPECT) {
dev_err(&chip->dev, "Data still expected\n");
rc = -EIO;
goto out_err;
}
/* Start the TPM command */
rc = tpm_cr50_i2c_write(chip, TPM_I2C_STS(0), tpm_go,
sizeof(tpm_go));
if (rc < 0) {
dev_err(&chip->dev, "Start command failed\n");
goto out_err;
}
return 0;
out_err:
/* Abort current transaction if still pending */
if (tpm_cr50_i2c_tis_status(chip) & TPM_STS_COMMAND_READY)
tpm_cr50_i2c_tis_set_ready(chip);
tpm_cr50_release_locality(chip, false);
return rc;
}
/**
* tpm_cr50_i2c_req_canceled() - Callback to notify a request cancel.
* @chip: A TPM chip.
* @status: Status given by the cancel callback.
*
* Return:
* True if command is ready, False otherwise.
*/
static bool tpm_cr50_i2c_req_canceled(struct tpm_chip *chip, u8 status)
{
return status == TPM_STS_COMMAND_READY;
}
static bool tpm_cr50_i2c_is_firmware_power_managed(struct device *dev)
{
u8 val;
int ret;
/* This flag should default true when the device property is not present */
ret = device_property_read_u8(dev, "firmware-power-managed", &val);
if (ret)
return true;
return val;
}
static const struct tpm_class_ops cr50_i2c = {
.flags = TPM_OPS_AUTO_STARTUP,
.status = &tpm_cr50_i2c_tis_status,
.recv = &tpm_cr50_i2c_tis_recv,
.send = &tpm_cr50_i2c_tis_send,
.cancel = &tpm_cr50_i2c_tis_set_ready,
.req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
.req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
.req_canceled = &tpm_cr50_i2c_req_canceled,
};
#ifdef CONFIG_ACPI
static const struct acpi_device_id cr50_i2c_acpi_id[] = {
{ "GOOG0005", 0 },
{}
};
MODULE_DEVICE_TABLE(acpi, cr50_i2c_acpi_id);
#endif
#ifdef CONFIG_OF
static const struct of_device_id of_cr50_i2c_match[] = {
{ .compatible = "google,cr50", },
{}
};
MODULE_DEVICE_TABLE(of, of_cr50_i2c_match);
#endif
/**
* tpm_cr50_i2c_probe() - Driver probe function.
* @client: I2C client information.
*
* Return:
* - 0: Success.
* - -errno: A POSIX error code.
*/
static int tpm_cr50_i2c_probe(struct i2c_client *client)
{
struct tpm_i2c_cr50_priv_data *priv;
struct device *dev = &client->dev;
struct tpm_chip *chip;
u32 vendor;
u8 buf[4];
int rc;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
return -ENODEV;
chip = tpmm_chip_alloc(dev, &cr50_i2c);
if (IS_ERR(chip))
return PTR_ERR(chip);
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
/* cr50 is a TPM 2.0 chip */
chip->flags |= TPM_CHIP_FLAG_TPM2;
if (tpm_cr50_i2c_is_firmware_power_managed(dev))
chip->flags |= TPM_CHIP_FLAG_FIRMWARE_POWER_MANAGED;
/* Default timeouts */
chip->timeout_a = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
chip->timeout_b = msecs_to_jiffies(TIS_LONG_TIMEOUT);
chip->timeout_c = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
chip->timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
dev_set_drvdata(&chip->dev, priv);
init_completion(&priv->tpm_ready);
if (client->irq > 0) {
rc = devm_request_irq(dev, client->irq, tpm_cr50_i2c_int_handler,
IRQF_TRIGGER_FALLING | IRQF_ONESHOT |
IRQF_NO_AUTOEN,
dev->driver->name, chip);
if (rc < 0) {
dev_err(dev, "Failed to probe IRQ %d\n", client->irq);
return rc;
}
priv->irq = client->irq;
} else {
dev_warn(dev, "No IRQ, will use %ums delay for TPM ready\n",
TPM_CR50_TIMEOUT_NOIRQ_MS);
}
rc = tpm_cr50_request_locality(chip);
if (rc < 0) {
dev_err(dev, "Could not request locality\n");
return rc;
}
/* Read four bytes from DID_VID register */
rc = tpm_cr50_i2c_read(chip, TPM_I2C_DID_VID(0), buf, sizeof(buf));
if (rc < 0) {
dev_err(dev, "Could not read vendor id\n");
tpm_cr50_release_locality(chip, true);
return rc;
}
vendor = le32_to_cpup((__le32 *)buf);
if (vendor != TPM_CR50_I2C_DID_VID && vendor != TPM_TI50_I2C_DID_VID) {
dev_err(dev, "Vendor ID did not match! ID was %08x\n", vendor);
tpm_cr50_release_locality(chip, true);
return -ENODEV;
}
dev_info(dev, "%s TPM 2.0 (i2c 0x%02x irq %d id 0x%x)\n",
vendor == TPM_TI50_I2C_DID_VID ? "ti50" : "cr50",
client->addr, client->irq, vendor >> 16);
return tpm_chip_register(chip);
}
/**
* tpm_cr50_i2c_remove() - Driver remove function.
* @client: I2C client information.
*
* Return:
* - 0: Success.
* - -errno: A POSIX error code.
*/
static void tpm_cr50_i2c_remove(struct i2c_client *client)
{
struct tpm_chip *chip = i2c_get_clientdata(client);
struct device *dev = &client->dev;
if (!chip) {
dev_crit(dev, "Could not get client data at remove, memory corruption ahead\n");
return;
}
tpm_chip_unregister(chip);
tpm_cr50_release_locality(chip, true);
}
static SIMPLE_DEV_PM_OPS(cr50_i2c_pm, tpm_pm_suspend, tpm_pm_resume);
static struct i2c_driver cr50_i2c_driver = {
.probe = tpm_cr50_i2c_probe,
.remove = tpm_cr50_i2c_remove,
.driver = {
.name = "cr50_i2c",
.pm = &cr50_i2c_pm,
.acpi_match_table = ACPI_PTR(cr50_i2c_acpi_id),
.of_match_table = of_match_ptr(of_cr50_i2c_match),
},
};
module_i2c_driver(cr50_i2c_driver);
MODULE_DESCRIPTION("cr50 TPM I2C Driver");
MODULE_LICENSE("GPL");
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