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tpm_tis_spi: Use single function to transfer data

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The algorithm for sending data to the TPM is mostly identical to the
algorithm for receiving data from the TPM, so a single function is
sufficient to handle both cases.

This is a prequisite for all the other fixes, so we don't have to fix
everything twice (send/receive)

v2: u16 instead of u8 for the length.
Cc: <stable@vger.kernel.org>
Fixes: 0edbfea537 ("tpm/tpm_tis_spi: Add support for spi phy")
Signed-off-by: Alexander Steffen <Alexander.Steffen@infineon.com>
Signed-off-by: Peter Huewe <peter.huewe@infineon.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Benoit Houyere <benoit.houyere@st.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
This commit is contained in:
Peter Huewe 2017-03-02 13:03:11 +00:00 committed by Jarkko Sakkinen
parent 095fc30c2c
commit f848f2143a
1 changed files with 24 additions and 63 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

87
drivers/char/tpm/tpm_tis_spi.c
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@ -47,8 +47,8 @@ struct tpm_tis_spi_phy {
struct tpm_tis_data priv;
struct spi_device *spi_device;
u8 tx_buf[MAX_SPI_FRAMESIZE + 4];
u8 rx_buf[MAX_SPI_FRAMESIZE + 4];
u8 tx_buf[4];
u8 rx_buf[4];
};
static inline struct tpm_tis_spi_phy *to_tpm_tis_spi_phy(struct tpm_tis_data *data)
@ -56,8 +56,8 @@ static inline struct tpm_tis_spi_phy *to_tpm_tis_spi_phy(struct tpm_tis_data *da
return container_of(data, struct tpm_tis_spi_phy, priv);
}
static int tpm_tis_spi_read_bytes(struct tpm_tis_data *data, u32 addr,
u16 len, u8 *result)
static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
u8 *buffer, u8 direction)
{
struct tpm_tis_spi_phy *phy = to_tpm_tis_spi_phy(data);
int ret, i;
@ -66,17 +66,17 @@ static int tpm_tis_spi_read_bytes(struct tpm_tis_data *data, u32 addr,
.tx_buf = phy->tx_buf,
.rx_buf = phy->rx_buf,
.len = 4,
.cs_change = 1,
};
if (len > MAX_SPI_FRAMESIZE)
return -ENOMEM;
phy->tx_buf[0] = 0x80 | (len - 1);
phy->tx_buf[0] = direction | (len - 1);
phy->tx_buf[1] = 0xd4;
phy->tx_buf[2] = (addr >> 8) & 0xFF;
phy->tx_buf[3] = addr & 0xFF;
phy->tx_buf[2] = addr >> 8;
phy->tx_buf[3] = addr;
spi_xfer.cs_change = 1;
spi_message_init(&m);
spi_message_add_tail(&spi_xfer, &m);
@ -85,7 +85,7 @@ static int tpm_tis_spi_read_bytes(struct tpm_tis_data *data, u32 addr,
if (ret < 0)
goto exit;
memset(phy->tx_buf, 0, len);
phy->tx_buf[0] = 0;
/* According to TCG PTP specification, if there is no TPM present at
* all, then the design has a weak pull-up on MISO. If a TPM is not
@ -103,7 +103,14 @@ static int tpm_tis_spi_read_bytes(struct tpm_tis_data *data, u32 addr,
spi_xfer.cs_change = 0;
spi_xfer.len = len;
spi_xfer.rx_buf = result;
if (direction) {
spi_xfer.tx_buf = NULL;
spi_xfer.rx_buf = buffer;
} else {
spi_xfer.tx_buf = buffer;
spi_xfer.rx_buf = NULL;
}
spi_message_init(&m);
spi_message_add_tail(&spi_xfer, &m);
@ -114,62 +121,16 @@ exit:
return ret;
}
static int tpm_tis_spi_read_bytes(struct tpm_tis_data *data, u32 addr,
u16 len, u8 *result)
{
return tpm_tis_spi_transfer(data, addr, len, result, 0x80);
}
static int tpm_tis_spi_write_bytes(struct tpm_tis_data *data, u32 addr,
u16 len, u8 *value)
{
struct tpm_tis_spi_phy *phy = to_tpm_tis_spi_phy(data);
int ret, i;
struct spi_message m;
struct spi_transfer spi_xfer = {
.tx_buf = phy->tx_buf,
.rx_buf = phy->rx_buf,
.len = 4,
};
if (len > MAX_SPI_FRAMESIZE)
return -ENOMEM;
phy->tx_buf[0] = len - 1;
phy->tx_buf[1] = 0xd4;
phy->tx_buf[2] = (addr >> 8) & 0xFF;
phy->tx_buf[3] = addr & 0xFF;
spi_xfer.cs_change = 1;
spi_message_init(&m);
spi_message_add_tail(&spi_xfer, &m);
spi_bus_lock(phy->spi_device->master);
ret = spi_sync_locked(phy->spi_device, &m);
if (ret < 0)
goto exit;
memset(phy->tx_buf, 0, len);
/* According to TCG PTP specification, if there is no TPM present at
* all, then the design has a weak pull-up on MISO. If a TPM is not
* present, a pull-up on MISO means that the SB controller sees a 1,
* and will latch in 0xFF on the read.
*/
for (i = 0; (phy->rx_buf[0] & 0x01) == 0 && i < TPM_RETRY; i++) {
spi_xfer.len = 1;
spi_message_init(&m);
spi_message_add_tail(&spi_xfer, &m);
ret = spi_sync_locked(phy->spi_device, &m);
if (ret < 0)
goto exit;
}
spi_xfer.len = len;
spi_xfer.tx_buf = value;
spi_xfer.cs_change = 0;
spi_xfer.tx_buf = value;
spi_message_init(&m);
spi_message_add_tail(&spi_xfer, &m);
ret = spi_sync_locked(phy->spi_device, &m);
exit:
spi_bus_unlock(phy->spi_device->master);
return ret;
return tpm_tis_spi_transfer(data, addr, len, value, 0);
}
static int tpm_tis_spi_read16(struct tpm_tis_data *data, u32 addr, u16 *result)