From 591e48c26ced7c455751eef27fb5963e902c2137 Mon Sep 17 00:00:00 2001 From: Peter Huewe Date: Thu, 2 Mar 2017 13:03:14 +0000 Subject: [PATCH] tpm_tis_spi: Remove limitation of transfers to MAX_SPI_FRAMESIZE bytes Limiting transfers to MAX_SPI_FRAMESIZE was not expected by the upper layers, as tpm_tis has no such limitation. Add a loop to hide that limitation. v2: Moved scope of spi_message to the top as requested by Jarkko Cc: Fixes: 0edbfea537d1 ("tpm/tpm_tis_spi: Add support for spi phy") Signed-off-by: Alexander Steffen Signed-off-by: Peter Huewe Reviewed-by: Jarkko Sakkinen Tested-by: Benoit Houyere Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm_tis_spi.c | 107 ++++++++++++++++++--------------- 1 file changed, 58 insertions(+), 49 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_spi.c b/drivers/char/tpm/tpm_tis_spi.c index 62f50b6c9ef6..3015c8b65f18 100644 --- a/drivers/char/tpm/tpm_tis_spi.c +++ b/drivers/char/tpm/tpm_tis_spi.c @@ -60,67 +60,76 @@ 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; + int ret = 0; + int i; struct spi_message m; - struct spi_transfer spi_xfer = { - .tx_buf = phy->tx_buf, - .rx_buf = phy->rx_buf, - .len = 4, - .cs_change = 1, - }; - - if (len > MAX_SPI_FRAMESIZE) - return -ENOMEM; + struct spi_transfer spi_xfer; + u8 transfer_len; - phy->tx_buf[0] = direction | (len - 1); - phy->tx_buf[1] = 0xd4; - phy->tx_buf[2] = addr >> 8; - phy->tx_buf[3] = addr; + spi_bus_lock(phy->spi_device->master); - spi_message_init(&m); - spi_message_add_tail(&spi_xfer, &m); + while (len) { + transfer_len = min_t(u16, len, MAX_SPI_FRAMESIZE); - spi_bus_lock(phy->spi_device->master); - ret = spi_sync_locked(phy->spi_device, &m); - if (ret < 0) - goto exit; - - if ((phy->rx_buf[3] & 0x01) == 0) { - // handle SPI wait states - phy->tx_buf[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) + phy->tx_buf[0] = direction | (transfer_len - 1); + phy->tx_buf[1] = 0xd4; + phy->tx_buf[2] = addr >> 8; + phy->tx_buf[3] = addr; + + memset(&spi_xfer, 0, sizeof(spi_xfer)); + spi_xfer.tx_buf = phy->tx_buf; + spi_xfer.rx_buf = phy->rx_buf; + spi_xfer.len = 4; + spi_xfer.cs_change = 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->rx_buf[3] & 0x01) == 0) { + // handle SPI wait states + phy->tx_buf[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->rx_buf[0] & 0x01) + break; + } + + if (i == TPM_RETRY) { + ret = -ETIMEDOUT; goto exit; - if (phy->rx_buf[0] & 0x01) - break; + } } - if (i == TPM_RETRY) { - ret = -ETIMEDOUT; - goto exit; + spi_xfer.cs_change = 0; + spi_xfer.len = transfer_len; + + if (direction) { + spi_xfer.tx_buf = NULL; + spi_xfer.rx_buf = buffer; + } else { + spi_xfer.tx_buf = buffer; + spi_xfer.rx_buf = NULL; } - } - spi_xfer.cs_change = 0; - spi_xfer.len = len; + 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 (direction) { - spi_xfer.tx_buf = NULL; - spi_xfer.rx_buf = buffer; - } else { - spi_xfer.tx_buf = buffer; - spi_xfer.rx_buf = NULL; + len -= transfer_len; + buffer += transfer_len; } - 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; -- 2.45.2