arm: XIlinx: QSPI driver: Update command sizes & allow data only transfers

These changes allow this driver to be used with the standard way of
transmitting SPI data in Linux. This enables the driver to be used
with the m25p80.c driver, among others.

Signed-off-by: Sadanand M <sadanan@xilinx.com>

diff --git a/drivers/spi/xilinx_qspipss.c b/drivers/spi/xilinx_qspipss.c
index 43c7987f4a1855df041d781034c843773ec98940..2cc4c3156bf877f0895a86afc2361e1c9be1a580 100755 (executable)
--- a/drivers/spi/xilinx_qspipss.c
+++ b/drivers/spi/xilinx_qspipss.c
@@ -186,8 +186,8 @@ struct xqspipss_inst_format {
 static struct xqspipss_inst_format __devinitdata flash_inst[] = {
        { XQSPIPSS_FLASH_OPCODE_WREN, 1, XQSPIPSS_TXD_00_01_OFFSET },
        { XQSPIPSS_FLASH_OPCODE_WRDS, 1, XQSPIPSS_TXD_00_01_OFFSET },
-       { XQSPIPSS_FLASH_OPCODE_RDSR1, 2, XQSPIPSS_TXD_00_10_OFFSET },
-       { XQSPIPSS_FLASH_OPCODE_RDSR2, 2, XQSPIPSS_TXD_00_10_OFFSET },
+       { XQSPIPSS_FLASH_OPCODE_RDSR1, 1, XQSPIPSS_TXD_00_01_OFFSET },
+       { XQSPIPSS_FLASH_OPCODE_RDSR2, 1, XQSPIPSS_TXD_00_01_OFFSET },
        { XQSPIPSS_FLASH_OPCODE_WRSR, 3, XQSPIPSS_TXD_00_11_OFFSET },
        { XQSPIPSS_FLASH_OPCODE_PP, 4, XQSPIPSS_TXD_00_00_OFFSET },
        { XQSPIPSS_FLASH_OPCODE_SE, 4, XQSPIPSS_TXD_00_00_OFFSET },
@@ -196,7 +196,7 @@ static struct xqspipss_inst_format __devinitdata flash_inst[] = {
        { XQSPIPSS_FLASH_OPCODE_BE, 1, XQSPIPSS_TXD_00_01_OFFSET },
        { XQSPIPSS_FLASH_OPCODE_ERASE_SUS, 1, XQSPIPSS_TXD_00_01_OFFSET },
        { XQSPIPSS_FLASH_OPCODE_ERASE_RES, 1, XQSPIPSS_TXD_00_01_OFFSET },
-       { XQSPIPSS_FLASH_OPCODE_RDID, 4, XQSPIPSS_TXD_00_00_OFFSET },
+       { XQSPIPSS_FLASH_OPCODE_RDID, 1, XQSPIPSS_TXD_00_01_OFFSET },
        { XQSPIPSS_FLASH_OPCODE_NORM_READ, 4, XQSPIPSS_TXD_00_00_OFFSET },
        { XQSPIPSS_FLASH_OPCODE_FAST_READ, 4, XQSPIPSS_TXD_00_00_OFFSET },
        { XQSPIPSS_FLASH_OPCODE_DUAL_READ, 4, XQSPIPSS_TXD_00_00_OFFSET },
@@ -606,9 +606,10 @@ static int xqspipss_start_transfer(struct spi_device *qspi,
                        if (instruction == flash_inst[index].opcode)
                                break;
 
-               /* Instruction is not supported, return error */
+               /* Instruction might have already been transmitted. This is a
+                * 'data only' transfer */
                if (index == ARRAY_SIZE(flash_inst))
-                       return 0;
+                       goto xfer_data;
 
                xqspi->curr_inst = &flash_inst[index];
                xqspi->inst_response = 1;
@@ -638,6 +639,7 @@ static int xqspipss_start_transfer(struct spi_device *qspi,
                }
        }
 
+xfer_data:
        INIT_COMPLETION(xqspi->done);
        if (xqspi->bytes_to_transfer)
                xqspipss_fill_tx_fifo(xqspi);
@@ -778,8 +780,11 @@ xqspipss_transfer(struct spi_device *qspi, struct spi_message *message)
                bits_per_word = bits_per_word ? : 32;
                if (!transfer->tx_buf && !transfer->rx_buf && transfer->len)
                        return -EINVAL;
-               if (bits_per_word != 32)
-                       return -EINVAL;
+               /* QSPI controller supports only 32 bit transfers whereas higher
+                * layer drivers request 8 bit transfers. Re-visit at a later
+                * time */
+               /* if (bits_per_word != 32)
+                       return -EINVAL; */
        }
 
        spin_lock_irqsave(&xqspi->trans_queue_lock, flags);