Merge branch 'parisc-4.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller...

[cascardo/linux.git] / drivers / spi / spi-rspi.c

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 8188433..a816f07 100644 (file)
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -295,14 +295,24 @@ static int rspi_set_config_register(struct rspi_data *rspi, int access_size)
 static int rspi_rz_set_config_register(struct rspi_data *rspi, int access_size)
 {
        int spbr;
+       int div = 0;
+       unsigned long clksrc;
 
        /* Sets output mode, MOSI signal, and (optionally) loopback */
        rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
 
+       clksrc = clk_get_rate(rspi->clk);
+       while (div < 3) {
+               if (rspi->max_speed_hz >= clksrc/4) /* 4=(CLK/2)/2 */
+                       break;
+               div++;
+               clksrc /= 2;
+       }
+
        /* Sets transfer bit rate */
-       spbr = DIV_ROUND_UP(clk_get_rate(rspi->clk),
-                           2 * rspi->max_speed_hz) - 1;
+       spbr = DIV_ROUND_UP(clksrc, 2 * rspi->max_speed_hz) - 1;
        rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
+       rspi->spcmd |= div << 2;
 
        /* Disable dummy transmission, set byte access */
        rspi_write8(rspi, SPDCR_SPLBYTE, RSPI_SPDCR);