Resending this patch to SPI mailing list as well. McSPI RX timeout issues are reported on some of the OMAP3 custom boards.
After verifying configuration sequence in TRM, there seems to be issue with McSPI configuration sequence. The steps to be followed for both TX and RX: 1. Configure OMAP2_MCSPI_CHCONF0 register with required settings such as TX/RX mode, word length, force chip select(if required). 2. Set MS bit to 0 in OMAP2_MCSPI_CHCTRL0 register to provide the clock. 3. Enable SPI channel in OMAP2_MCSPI_MODULCTRL But, the sequence used in current code seems to be wrong. Here it is: 1. Set MS bit to 0 in OMAP2_MCSPI_CHCTRL0 register to provide the clock (This is done during bootup) 2. Enable SPI channel in OMAP2_MCSPI_MODULCTRL 3. Configure OMAP2_MCSPI_CHCONF0 register with required settings such as TX/RX mode, word length, force chip select(if required). After correcting configuration sequence, the timeout seems to be not reproducible anymore. Signed-off-by: Manjunatha GK <[email protected]> --- drivers/spi/omap2_mcspi.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c index ba1a872..846485c 100644 --- a/drivers/spi/omap2_mcspi.c +++ b/drivers/spi/omap2_mcspi.c @@ -802,7 +802,6 @@ static void omap2_mcspi_work(struct work_struct *work) spi = m->spi; cs = spi->controller_state; - omap2_mcspi_set_enable(spi, 1); list_for_each_entry(t, &m->transfers, transfer_list) { if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) { status = -EINVAL; @@ -830,6 +829,9 @@ static void omap2_mcspi_work(struct work_struct *work) chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY; mcspi_write_chconf0(spi, chconf); + omap2_mcspi_set_master_mode(mcspi->master); + + omap2_mcspi_set_enable(spi, 1); if (t->len) { unsigned count; -- 1.6.0.4 ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ spi-devel-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/spi-devel-general
