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 the basic idea of adding dual/quad support in spi framework. $subject patch will undergo changes with the ongoing discussion in the community. 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 <sourav.pod...@ti.com> --- drivers/spi/spi-ti-qspi.c | 16 ++++++++++++++-- 1 files changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi-ti-qspi.c b/drivers/spi/spi-ti-qspi.c index 7c848c8..679c813 100644 --- a/drivers/spi/spi-ti-qspi.c +++ b/drivers/spi/spi-ti-qspi.c @@ -86,6 +86,7 @@ struct ti_qspi { #define QSPI_3_PIN (1 << 18) #define QSPI_RD_SNGL (1 << 16) #define QSPI_WR_SNGL (2 << 16) +#define QSPI_RD_DUAL (3 << 16) #define QSPI_RD_QUAD (7 << 16) #define QSPI_INVAL (4 << 16) #define QSPI_WC_CMD_INT_EN (1 << 14) @@ -290,6 +291,7 @@ static void qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t) { u8 *rxbuf; int wlen, count; + unsigned cmd = qspi->cmd; count = t->len; rxbuf = t->rx_buf; @@ -299,8 +301,18 @@ static void qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t) dev_dbg(qspi->dev, "rx cmd %08x dc %08x\n", qspi->cmd | QSPI_RD_SNGL, qspi->dc); ti_qspi_write(qspi, qspi->dc, QSPI_SPI_DC_REG); - ti_qspi_write(qspi, qspi->cmd | QSPI_RD_SNGL, - QSPI_SPI_CMD_REG); + 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; + } + ti_qspi_writel(qspi, cmd, QSPI_SPI_CMD_REG); ti_qspi_write(qspi, QSPI_WC_INT_EN, QSPI_INTR_ENABLE_SET_REG); wait_for_completion(&qspi->transfer_complete); ti_qspi_read_data(qspi, QSPI_SPI_DATA_REG, wlen, &rxbuf); -- 1.7.1 ------------------------------------------------------------------------------ See everything from the browser to the database with AppDynamics Get end-to-end visibility with application monitoring from AppDynamics Isolate bottlenecks and diagnose root cause in seconds. Start your free trial of AppDynamics Pro today! http://pubads.g.doubleclick.net/gampad/clk?id=48808831&iu=/4140/ostg.clktrk _______________________________________________ spi-devel-general mailing list spi-devel-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spi-devel-general
