Cr50 firmware has a different flow control protocol than the one used by this TPM PTP SPI driver. Introduce a flow control callback so we can override the standard sequence with the custom one that Cr50 uses.
Cc: Andrey Pronin <[email protected]> Cc: Duncan Laurie <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Guenter Roeck <[email protected]> Cc: Alexander Steffen <[email protected]> Signed-off-by: Stephen Boyd <[email protected]> --- drivers/char/tpm/tpm_tis_spi.c | 55 +++++++++++++++++++++------------- 1 file changed, 34 insertions(+), 21 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_spi.c b/drivers/char/tpm/tpm_tis_spi.c index 19513e622053..819602e85b34 100644 --- a/drivers/char/tpm/tpm_tis_spi.c +++ b/drivers/char/tpm/tpm_tis_spi.c @@ -42,6 +42,8 @@ struct tpm_tis_spi_phy { struct tpm_tis_data priv; struct spi_device *spi_device; + int (*flow_control)(struct tpm_tis_spi_phy *phy, + struct spi_transfer *xfer); u8 *iobuf; }; @@ -50,12 +52,39 @@ 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_flow_control(struct tpm_tis_spi_phy *phy, + struct spi_transfer *spi_xfer) +{ + struct spi_message m; + int ret, i; + + if ((phy->iobuf[3] & 0x01) == 0) { + // handle SPI wait states + phy->iobuf[0] = 0; + + for (i = 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) + return ret; + if (phy->iobuf[0] & 0x01) + break; + } + + if (i == TPM_RETRY) + return -ETIMEDOUT; + } + + return 0; +} + static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len, u8 *in, const u8 *out) { struct tpm_tis_spi_phy *phy = to_tpm_tis_spi_phy(data); int ret = 0; - int i; struct spi_message m; struct spi_transfer spi_xfer; u8 transfer_len; @@ -82,26 +111,9 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len, if (ret < 0) goto exit; - if ((phy->iobuf[3] & 0x01) == 0) { - // handle SPI wait states - phy->iobuf[0] = 0; - - for (i = 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; - if (phy->iobuf[0] & 0x01) - break; - } - - if (i == TPM_RETRY) { - ret = -ETIMEDOUT; - goto exit; - } - } + ret = phy->flow_control(phy, &spi_xfer); + if (ret < 0) + goto exit; spi_xfer.cs_change = 0; spi_xfer.len = transfer_len; @@ -207,6 +219,7 @@ static int tpm_tis_spi_probe(struct spi_device *dev) phy->iobuf = devm_kmalloc(&dev->dev, MAX_SPI_FRAMESIZE, GFP_KERNEL); if (!phy->iobuf) return -ENOMEM; + phy->flow_control = tpm_tis_spi_flow_control; /* If the SPI device has an IRQ then use that */ if (dev->irq > 0) -- Sent by a computer through tubes
