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: <stable@vger.kernel.org>
Fixes: 0edbfea537d1 ("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>

diff --git a/drivers/char/tpm/tpm_tis_spi.c b/drivers/char/tpm/tpm_tis_spi.c
index 62f50b6c9ef69939dcd38faae9df586794cdbdf3..3015c8b65f18143b17b81491e813ed873a5fccdd 100644 (file)
--- 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;