@@ -202,8 +202,6 @@ static int tpm_cr50_i2c_read(struct tpm_chip *chip, u8 addr, u8 *buffer, size_t
};
int rc;
- i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
-
/* Prepare for completion interrupt */
tpm_cr50_i2c_enable_tpm_irq(chip);
@@ -222,7 +220,6 @@ static int tpm_cr50_i2c_read(struct tpm_chip *chip, u8 addr, u8 *buffer, size_t
out:
tpm_cr50_i2c_disable_tpm_irq(chip);
- i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
if (rc < 0)
return rc;
@@ -264,8 +261,6 @@ static int tpm_cr50_i2c_write(struct tpm_chip *chip, u8 addr, u8 *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);
@@ -279,7 +274,6 @@ static int tpm_cr50_i2c_write(struct tpm_chip *chip, u8 addr, u8 *buffer,
out:
tpm_cr50_i2c_disable_tpm_irq(chip);
- i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
if (rc < 0)
return rc;
@@ -323,6 +317,7 @@ static int tpm_cr50_check_locality(struct tpm_chip *chip, int loc)
*/
static int tpm_cr50_release_locality(struct tpm_chip *chip, int loc)
{
+ struct i2c_client *client = to_i2c_client(chip->dev.parent);
u8 mask = TPM_ACCESS_VALID | TPM_ACCESS_REQUEST_PENDING;
u8 addr = TPM_I2C_ACCESS(loc);
u8 buf;
@@ -330,13 +325,15 @@ static int tpm_cr50_release_locality(struct tpm_chip *chip, int loc)
rc = tpm_cr50_i2c_read(chip, addr, &buf, sizeof(buf));
if (rc < 0)
- return rc;
+ goto unlock_out;
if ((buf & mask) == mask) {
buf = TPM_ACCESS_ACTIVE_LOCALITY;
rc = tpm_cr50_i2c_write(chip, addr, &buf, sizeof(buf));
}
+unlock_out:
+ i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
return rc;
}
@@ -351,16 +348,19 @@ static int tpm_cr50_release_locality(struct tpm_chip *chip, int loc)
*/
static int tpm_cr50_request_locality(struct tpm_chip *chip, int loc)
{
+ struct i2c_client *client = to_i2c_client(chip->dev.parent);
u8 buf = TPM_ACCESS_REQUEST_USE;
unsigned long stop;
int rc;
+ i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
+
if (tpm_cr50_check_locality(chip, loc) == loc)
return loc;
rc = tpm_cr50_i2c_write(chip, TPM_I2C_ACCESS(loc), &buf, sizeof(buf));
if (rc < 0)
- return rc;
+ goto unlock_out;
stop = jiffies + chip->timeout_a;
do {
@@ -370,7 +370,11 @@ static int tpm_cr50_request_locality(struct tpm_chip *chip, int loc)
msleep(TPM_CR50_TIMEOUT_SHORT_MS);
} while (time_before(jiffies, stop));
- return -ETIMEDOUT;
+ rc = -ETIMEDOUT;
+
+unlock_out:
+ i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
+ return rc;
}
/**
Move i2c locking primitives to request_locality and relinquish_locality callbacks, what effectively blocks TPM bus for the whole duration of logical TPM operation. With this in place, cr50-equipped TPM may be shared with external CPUs - assuming that underneath i2c controller driver is aware of this setup (see i2c-designware-amdpsp as an example). Signed-off-by: Jan Dabros <jsd@semihalf.com> --- drivers/char/tpm/tpm_tis_i2c_cr50.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-)