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path: root/drivers/char/tpm/tpm_i2c_infineon.c
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Diffstat (limited to 'drivers/char/tpm/tpm_i2c_infineon.c')
-rw-r--r--drivers/char/tpm/tpm_i2c_infineon.c180
1 files changed, 137 insertions, 43 deletions
diff --git a/drivers/char/tpm/tpm_i2c_infineon.c b/drivers/char/tpm/tpm_i2c_infineon.c
index 8fe7ac3d095b..37d5dcc10ea7 100644
--- a/drivers/char/tpm/tpm_i2c_infineon.c
+++ b/drivers/char/tpm/tpm_i2c_infineon.c
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2012 Infineon Technologies
+ * Copyright (C) 2012,2013 Infineon Technologies
*
* Authors:
* Peter Huewe <peter.huewe@infineon.com>
@@ -56,13 +56,21 @@
#define TPM_TIMEOUT_US_HI (TPM_TIMEOUT_US_LOW + 2000)
/* expected value for DIDVID register */
-#define TPM_TIS_I2C_DID_VID 0x000b15d1L
+#define TPM_TIS_I2C_DID_VID_9635 0xd1150b00L
+#define TPM_TIS_I2C_DID_VID_9645 0x001a15d1L
+
+enum i2c_chip_type {
+ SLB9635,
+ SLB9645,
+ UNKNOWN,
+};
/* Structure to store I2C TPM specific stuff */
struct tpm_inf_dev {
struct i2c_client *client;
u8 buf[TPM_BUFSIZE + sizeof(u8)]; /* max. buffer size + addr */
struct tpm_chip *chip;
+ enum i2c_chip_type chip_type;
};
static struct tpm_inf_dev tpm_dev;
@@ -90,10 +98,20 @@ static struct i2c_driver tpm_tis_i2c_driver;
static int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
{
- struct i2c_msg msg1 = { tpm_dev.client->addr, 0, 1, &addr };
- struct i2c_msg msg2 = { tpm_dev.client->addr, I2C_M_RD, len, buffer };
+ struct i2c_msg msg1 = {
+ .addr = tpm_dev.client->addr,
+ .len = 1,
+ .buf = &addr
+ };
+ struct i2c_msg msg2 = {
+ .addr = tpm_dev.client->addr,
+ .flags = I2C_M_RD,
+ .len = len,
+ .buf = buffer
+ };
+ struct i2c_msg msgs[] = {msg1, msg2};
- int rc;
+ int rc = 0;
int count;
/* Lock the adapter for the duration of the whole sequence. */
@@ -101,30 +119,53 @@ static int iic_tpm_read(u8 addr, u8 *buffer, size_t len)
return -EOPNOTSUPP;
i2c_lock_adapter(tpm_dev.client->adapter);
- for (count = 0; count < MAX_COUNT; count++) {
- rc = __i2c_transfer(tpm_dev.client->adapter, &msg1, 1);
- if (rc > 0)
- break; /* break here to skip sleep */
-
- usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
- }
-
- if (rc <= 0)
- goto out;
-
- /* After the TPM has successfully received the register address it needs
- * some time, thus we're sleeping here again, before retrieving the data
- */
- for (count = 0; count < MAX_COUNT; count++) {
- usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
- rc = __i2c_transfer(tpm_dev.client->adapter, &msg2, 1);
- if (rc > 0)
- break;
+ if (tpm_dev.chip_type == SLB9645) {
+ /* use a combined read for newer chips
+ * unfortunately the smbus functions are not suitable due to
+ * the 32 byte limit of the smbus.
+ * retries should usually not be needed, but are kept just to
+ * be on the safe side.
+ */
+ for (count = 0; count < MAX_COUNT; count++) {
+ rc = __i2c_transfer(tpm_dev.client->adapter, msgs, 2);
+ if (rc > 0)
+ break; /* break here to skip sleep */
+ usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
+ }
+ } else {
+ /* slb9635 protocol should work in all cases */
+ for (count = 0; count < MAX_COUNT; count++) {
+ rc = __i2c_transfer(tpm_dev.client->adapter, &msg1, 1);
+ if (rc > 0)
+ break; /* break here to skip sleep */
+
+ usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
+ }
+ if (rc <= 0)
+ goto out;
+
+ /* After the TPM has successfully received the register address
+ * it needs some time, thus we're sleeping here again, before
+ * retrieving the data
+ */
+ for (count = 0; count < MAX_COUNT; count++) {
+ usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
+ rc = __i2c_transfer(tpm_dev.client->adapter, &msg2, 1);
+ if (rc > 0)
+ break;
+ }
}
out:
i2c_unlock_adapter(tpm_dev.client->adapter);
+ /* take care of 'guard time' */
+ usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
+
+ /* __i2c_transfer returns the number of successfully transferred
+ * messages.
+ * So rc should be greater than 0 here otherwise we have an error.
+ */
if (rc <= 0)
return -EIO;
@@ -138,7 +179,11 @@ static int iic_tpm_write_generic(u8 addr, u8 *buffer, size_t len,
int rc = -EIO;
int count;
- struct i2c_msg msg1 = { tpm_dev.client->addr, 0, len + 1, tpm_dev.buf };
+ struct i2c_msg msg1 = {
+ .addr = tpm_dev.client->addr,
+ .len = len + 1,
+ .buf = tpm_dev.buf
+ };
if (len > TPM_BUFSIZE)
return -EINVAL;
@@ -154,16 +199,24 @@ static int iic_tpm_write_generic(u8 addr, u8 *buffer, size_t len,
/*
* NOTE: We have to use these special mechanisms here and unfortunately
* cannot rely on the standard behavior of i2c_transfer.
+ * Even for newer chips the smbus functions are not
+ * suitable due to the 32 byte limit of the smbus.
*/
for (count = 0; count < max_count; count++) {
rc = __i2c_transfer(tpm_dev.client->adapter, &msg1, 1);
if (rc > 0)
break;
-
usleep_range(sleep_low, sleep_hi);
}
i2c_unlock_adapter(tpm_dev.client->adapter);
+ /* take care of 'guard time' */
+ usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI);
+
+ /* __i2c_transfer returns the number of successfully transferred
+ * messages.
+ * So rc should be greater than 0 here otherwise we have an error.
+ */
if (rc <= 0)
return -EIO;
@@ -283,11 +336,18 @@ static int request_locality(struct tpm_chip *chip, int loc)
static u8 tpm_tis_i2c_status(struct tpm_chip *chip)
{
/* NOTE: since I2C read may fail, return 0 in this case --> time-out */
- u8 buf;
- if (iic_tpm_read(TPM_STS(chip->vendor.locality), &buf, 1) < 0)
- return 0;
- else
- return buf;
+ u8 buf = 0xFF;
+ u8 i = 0;
+
+ do {
+ if (iic_tpm_read(TPM_STS(chip->vendor.locality), &buf, 1) < 0)
+ return 0;
+
+ i++;
+ /* if locallity is set STS should not be 0xFF */
+ } while ((buf == 0xFF) && i < 10);
+
+ return buf;
}
static void tpm_tis_i2c_ready(struct tpm_chip *chip)
@@ -328,7 +388,7 @@ static int wait_for_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
/* check current status */
*status = tpm_tis_i2c_status(chip);
- if ((*status & mask) == mask)
+ if ((*status != 0xFF) && (*status & mask) == mask)
return 0;
stop = jiffies + timeout;
@@ -372,7 +432,6 @@ static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
/* avoid endless loop in case of broken HW */
if (retries > MAX_COUNT_LONG)
return -EIO;
-
}
return size;
}
@@ -480,7 +539,6 @@ static int tpm_tis_i2c_send(struct tpm_chip *chip, u8 *buf, size_t len)
rc = -EIO;
goto out_err;
}
-
}
/* write last byte */
@@ -568,6 +626,7 @@ static int tpm_tis_i2c_init(struct device *dev)
chip = tpm_register_hardware(dev, &tpm_tis_i2c);
if (!chip) {
+ dev_err(dev, "could not register hardware\n");
rc = -ENODEV;
goto out_err;
}
@@ -582,20 +641,24 @@ static int tpm_tis_i2c_init(struct device *dev)
chip->vendor.timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
if (request_locality(chip, 0) != 0) {
+ dev_err(dev, "could not request locality\n");
rc = -ENODEV;
goto out_vendor;
}
/* read four bytes from DID_VID register */
if (iic_tpm_read(TPM_DID_VID(0), (u8 *)&vendor, 4) < 0) {
+ dev_err(dev, "could not read vendor id\n");
rc = -EIO;
goto out_release;
}
- /* create DID_VID register value, after swapping to little-endian */
- vendor = be32_to_cpu((__be32) vendor);
-
- if (vendor != TPM_TIS_I2C_DID_VID) {
+ if (vendor == TPM_TIS_I2C_DID_VID_9645) {
+ tpm_dev.chip_type = SLB9645;
+ } else if (vendor == TPM_TIS_I2C_DID_VID_9635) {
+ tpm_dev.chip_type = SLB9635;
+ } else {
+ dev_err(dev, "vendor id did not match! ID was %08x\n", vendor);
rc = -ENODEV;
goto out_release;
}
@@ -631,22 +694,53 @@ out_err:
static const struct i2c_device_id tpm_tis_i2c_table[] = {
{"tpm_i2c_infineon", 0},
+ {"slb9635tt", 0},
+ {"slb9645tt", 1},
{},
};
MODULE_DEVICE_TABLE(i2c, tpm_tis_i2c_table);
+
+#ifdef CONFIG_OF
+static const struct of_device_id tpm_tis_i2c_of_match[] = {
+ {
+ .name = "tpm_i2c_infineon",
+ .type = "tpm",
+ .compatible = "infineon,tpm_i2c_infineon",
+ .data = (void *)0
+ },
+ {
+ .name = "slb9635tt",
+ .type = "tpm",
+ .compatible = "infineon,slb9635tt",
+ .data = (void *)0
+ },
+ {
+ .name = "slb9645tt",
+ .type = "tpm",
+ .compatible = "infineon,slb9645tt",
+ .data = (void *)1
+ },
+ {},
+};
+MODULE_DEVICE_TABLE(of, tpm_tis_i2c_of_match);
+#endif
+
static SIMPLE_DEV_PM_OPS(tpm_tis_i2c_ops, tpm_pm_suspend, tpm_pm_resume);
static int tpm_tis_i2c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int rc;
- if (tpm_dev.client != NULL)
+ struct device *dev = &(client->dev);
+
+ if (tpm_dev.client != NULL) {
+ dev_err(dev, "This driver only supports one client at a time\n");
return -EBUSY; /* We only support one client */
+ }
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
- dev_err(&client->dev,
- "no algorithms associated to the i2c bus\n");
+ dev_err(dev, "no algorithms associated to the i2c bus\n");
return -ENODEV;
}
@@ -682,7 +776,6 @@ static int tpm_tis_i2c_remove(struct i2c_client *client)
}
static struct i2c_driver tpm_tis_i2c_driver = {
-
.id_table = tpm_tis_i2c_table,
.probe = tpm_tis_i2c_probe,
.remove = tpm_tis_i2c_remove,
@@ -690,11 +783,12 @@ static struct i2c_driver tpm_tis_i2c_driver = {
.name = "tpm_i2c_infineon",
.owner = THIS_MODULE,
.pm = &tpm_tis_i2c_ops,
+ .of_match_table = of_match_ptr(tpm_tis_i2c_of_match),
},
};
module_i2c_driver(tpm_tis_i2c_driver);
MODULE_AUTHOR("Peter Huewe <peter.huewe@infineon.com>");
MODULE_DESCRIPTION("TPM TIS I2C Infineon Driver");
-MODULE_VERSION("2.1.5");
+MODULE_VERSION("2.2.0");
MODULE_LICENSE("GPL");