spi: spi-mxc: implement clk control for ECSPI to fix SPI_MODE_3

SPI_MODE_3 requires clk high when inactive. The SCLK_CTL
field of the config reg was not configured in case of CPOL.
Fix configuration so that SPI_MODE_3 which uses CPOL configures
the clk line to be high in inactive state.

Signed-off-by: Markus Niebel <Markus.Niebel@tqs.de>
Reviewed-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>

diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c
index 95dd03f7b3ff5ab43d33a37a2a8c1f495e2ae82a..f3f029d634abd1f2045c20ba3e159bc1aecf7e4a 100644 (file)
--- a/drivers/spi/mxc_spi.c
+++ b/drivers/spi/mxc_spi.c
@@ -115,7 +115,8 @@ static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs,
 {
        u32 clk_src = mxc_get_clock(MXC_CSPI_CLK);
        s32 reg_ctrl, reg_config;
-       u32 ss_pol = 0, sclkpol = 0, sclkpha = 0, pre_div = 0, post_div = 0;
+       u32 ss_pol = 0, sclkpol = 0, sclkpha = 0, sclkctl = 0;
+       u32 pre_div = 0, post_div = 0;
        struct cspi_regs *regs = (struct cspi_regs *)mxcs->base;
 
        if (max_hz == 0) {
@@ -164,8 +165,10 @@ static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs,
        if (mode & SPI_CS_HIGH)
                ss_pol = 1;
 
-       if (mode & SPI_CPOL)
+       if (mode & SPI_CPOL) {
                sclkpol = 1;
+               sclkctl = 1;
+       }
 
        if (mode & SPI_CPHA)
                sclkpha = 1;
@@ -180,6 +183,8 @@ static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs,
                (ss_pol << (cs + MXC_CSPICON_SSPOL));
        reg_config = (reg_config & ~(1 << (cs + MXC_CSPICON_POL))) |
                (sclkpol << (cs + MXC_CSPICON_POL));
+       reg_config = (reg_config & ~(1 << (cs + MXC_CSPICON_CTL))) |
+               (sclkctl << (cs + MXC_CSPICON_CTL));
        reg_config = (reg_config & ~(1 << (cs + MXC_CSPICON_PHA))) |
                (sclkpha << (cs + MXC_CSPICON_PHA));