Since, qspi controller uses quad read.

Configuring the command register, if the transfer of data needs
dual or quad lines.

This patch has been done on top of the following patch[1], which is just the
basic idea of adding dual/quad support in spi framework.
$subject patch will undergo changes once the ongoing discussion in the
community is freezed.

This patch is posted to demonstrate how patch 1 of the series will support
quad read.

[1]: http://comments.gmane.org/gmane.linux.kernel.spi.devel/14047

Signed-off-by: Sourav Poddar <[email protected]>
---
 drivers/spi/spi-ti-qspi.c |   22 ++++++++++++++++------
 1 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/spi/spi-ti-qspi.c b/drivers/spi/spi-ti-qspi.c
index 73a1675..fac1722 100644
--- a/drivers/spi/spi-ti-qspi.c
+++ b/drivers/spi/spi-ti-qspi.c
@@ -265,18 +265,30 @@ static int qspi_write_msg(struct ti_qspi *qspi, struct 
spi_transfer *t)
 static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t)
 {
        int wlen, count, ret;
+       unsigned cmd = qspi->cmd;
 
        count = t->len;
        wlen = t->bits_per_word;
 
+       switch (t->bitwidth) {
+       case SPI_BITWIDTH_QUAD:
+               cmd |= QSPI_RD_QUAD;
+               break;
+       case SPI_BITWIDTH_DUAL:
+               cmd |= QSPI_RD_DUAL;
+               break;
+       case SPI_BITWIDTH_SINGLE:
+       default:
+               cmd |= QSPI_RD_SNGL;
+       }
+
        if (wlen == 8) {
                u8        *rxbuf;
                rxbuf = t->rx_buf;
                do {
                        dev_dbg(qspi->dev, "rx cmd %08x dc %08x\n",
                                qspi->cmd | QSPI_RD_SNGL, qspi->dc);
-                       ti_qspi_write(qspi, qspi->cmd | QSPI_RD_SNGL,
-                               QSPI_SPI_CMD_REG);
+                       ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
                        ret = 
wait_for_completion_timeout(&qspi->transfer_complete,
                                QSPI_COMPLETION_TIMEOUT);
                        if (ret == 0) {
@@ -294,8 +306,7 @@ static int qspi_read_msg(struct ti_qspi *qspi, struct 
spi_transfer *t)
                do {
                        dev_dbg(qspi->dev, "rx cmd %08x dc %08x\n",
                                qspi->cmd | QSPI_RD_SNGL, qspi->dc);
-                       ti_qspi_write(qspi, qspi->cmd | QSPI_RD_SNGL,
-                               QSPI_SPI_CMD_REG);
+                       ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
                        ret = 
wait_for_completion_timeout(&qspi->transfer_complete,
                                        QSPI_COMPLETION_TIMEOUT);
                        if (ret == 0) {
@@ -313,8 +324,7 @@ static int qspi_read_msg(struct ti_qspi *qspi, struct 
spi_transfer *t)
                do {
                        dev_dbg(qspi->dev, "rx cmd %08x dc %08x\n",
                                qspi->cmd | QSPI_RD_SNGL, qspi->dc);
-                       ti_qspi_write(qspi, qspi->cmd | QSPI_RD_SNGL,
-                               QSPI_SPI_CMD_REG);
+                       ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
                        ret = 
wait_for_completion_timeout(&qspi->transfer_complete,
                                        QSPI_COMPLETION_TIMEOUT);
                        if (ret == 0) {
-- 
1.7.1


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