diff --git a/drivers/char/tpm/tpm_tis_spi_main.c b/drivers/char/tpm/tpm_tis_spi_main.c index 9bfaba092a06..a62f5c7f38d3 100644 --- a/drivers/char/tpm/tpm_tis_spi_main.c +++ b/drivers/char/tpm/tpm_tis_spi_main.c @@ -71,8 +71,74 @@ static int tpm_tis_spi_flow_control(struct tpm_tis_spi_phy *phy, return 0; } -int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len, - u8 *in, const u8 *out) +/* + * Half duplex controller with support for TPM wait state detection like + * Tegra QSPI need CMD, ADDR & DATA sent in single message to manage HW flow + * control. Each phase sent in different transfer for controller to idenity + * phase. + */ +static int tpm_tis_spi_transfer_half(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); + struct spi_transfer spi_xfer[3]; + struct spi_message m; + u8 transfer_len; + int ret; + + while (len) { + transfer_len = min_t(u16, len, MAX_SPI_FRAMESIZE); + + spi_message_init(&m); + phy->iobuf[0] = (in ? 0x80 : 0) | (transfer_len - 1); + phy->iobuf[1] = 0xd4; + phy->iobuf[2] = addr >> 8; + phy->iobuf[3] = addr; + + memset(&spi_xfer, 0, sizeof(spi_xfer)); + + spi_xfer[0].tx_buf = phy->iobuf; + spi_xfer[0].len = 1; + spi_message_add_tail(&spi_xfer[0], &m); + + spi_xfer[1].tx_buf = phy->iobuf + 1; + spi_xfer[1].len = 3; + spi_message_add_tail(&spi_xfer[1], &m); + + if (out) { + spi_xfer[2].tx_buf = &phy->iobuf[4]; + spi_xfer[2].rx_buf = NULL; + memcpy(&phy->iobuf[4], out, transfer_len); + out += transfer_len; + } + + if (in) { + spi_xfer[2].tx_buf = NULL; + spi_xfer[2].rx_buf = &phy->iobuf[4]; + } + + spi_xfer[2].len = transfer_len; + spi_message_add_tail(&spi_xfer[2], &m); + + reinit_completion(&phy->ready); + + ret = spi_sync(phy->spi_device, &m); + if (ret < 0) + return ret; + + if (in) { + memcpy(in, &phy->iobuf[4], transfer_len); + in += transfer_len; + } + + len -= transfer_len; + } + + return ret; +} + +static int tpm_tis_spi_transfer_full(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; @@ -148,6 +214,24 @@ exit: return ret; } +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); + struct spi_controller *ctlr = phy->spi_device->controller; + + /* + * TPM flow control over SPI requires full duplex support. + * Send entire message to a half duplex controller to handle + * wait polling in controller. + * Set TPM HW flow control flag.. + */ + if (ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) + return tpm_tis_spi_transfer_half(data, addr, len, in, out); + else + return tpm_tis_spi_transfer_full(data, addr, len, in, out); +} + static int tpm_tis_spi_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len, u8 *result, enum tpm_tis_io_mode io_mode) { @@ -189,6 +273,9 @@ static int tpm_tis_spi_probe(struct spi_device *dev) phy->flow_control = tpm_tis_spi_flow_control; + if (dev->controller->flags & SPI_CONTROLLER_HALF_DUPLEX) + dev->mode |= SPI_TPM_HW_FLOW; + /* If the SPI device has an IRQ then use that */ if (dev->irq > 0) irq = dev->irq;