spi/pxa2xx: add support for SPI_LOOP

This is useful when testing the functionality of the controller from userspace
and there aren't any real SPI slave devices connected to the bus.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Lu Cao <lucao@marvell.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index 7f8f939..8a5ba0a 100644 (file)
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -846,6 +846,9 @@ static int setup(struct spi_device *spi)
        chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) ? SSCR1_SPH : 0)
                        | (((spi->mode & SPI_CPOL) != 0) ? SSCR1_SPO : 0);
 
+       if (spi->mode & SPI_LOOP)
+               chip->cr1 |= SSCR1_LBM;
+
        /* NOTE:  PXA25x_SSP _could_ use external clocking ... */
        if (!pxa25x_ssp_comp(drv_data))
                dev_dbg(&spi->dev, "%ld Hz actual, %s\n",
@@ -939,7 +942,7 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
        master->dev.parent = &pdev->dev;
        master->dev.of_node = pdev->dev.of_node;
        /* the spi->mode bits understood by this driver: */
-       master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+       master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
 
        master->bus_num = ssp->port_id;
        master->num_chipselect = platform_info->num_chipselect;