spi: sirf: set SPI controller in RISC IO chipselect mode
authorQipan Li <Qipan.Li@csr.com>
Mon, 14 Apr 2014 06:29:58 +0000 (14:29 +0800)
committerMark Brown <broonie@linaro.org>
Mon, 14 Apr 2014 20:02:54 +0000 (21:02 +0100)
SPI bitbang supply "chipselect" interface for change chip-select line
, in the SiRFSoC SPI controller, we need to enable "SPI_CS_IO_MODE",
otherwise, spi_sirfsoc_chipselect() has no effect.
now the driver is working is because SPI controller will control CS
automatically without SPI_CS_IO_MODE. this patch makes the CS controller
really controlled by software.

Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
drivers/spi/spi-sirf.c

index 51d7c988d3aec16d133081c1ea2e155692868fbe..9b30743d816a10e687b8fd752e66da9b8b3a0ffe 100644 (file)
@@ -559,6 +559,11 @@ spi_sirfsoc_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
                regval &= ~SIRFSOC_SPI_CMD_MODE;
                sspi->tx_by_cmd = false;
        }
+       /*
+        * set spi controller in RISC chipselect mode, we are controlling CS by
+        * software BITBANG_CS_ACTIVE and BITBANG_CS_INACTIVE.
+        */
+       regval |= SIRFSOC_SPI_CS_IO_MODE;
        writel(regval, sspi->base + SIRFSOC_SPI_CTRL);
 
        if (IS_DMA_VALID(t)) {