spi: imx: set spi_bus_clk for mx21 and mx27

Introduce additional output parameter in spi_imx_clkdiv_1()
function to return result frequency and set it to spi_bus_clk.

This fixes division by zero bug, which occurred in
spi_imx_calculate_timeout() function.

Signed-off-by: Robert Baldyga <r.baldyga@hackerion.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 08124b29665ec70062ec3a9a7eb127c5580f2a17..32ced64a5bb9a012e2edd0d415d8c477ebc0522a 100644 (file)
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -173,15 +173,16 @@ static int mxc_clkdivs[] = {0, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 128, 192,
 
 /* MX21, MX27 */
 static unsigned int spi_imx_clkdiv_1(unsigned int fin,
-               unsigned int fspi, unsigned int max)
+               unsigned int fspi, unsigned int max, unsigned int *fres)
 {
        int i;
 
        for (i = 2; i < max; i++)
                if (fspi * mxc_clkdivs[i] >= fin)
-                       return i;
+                       break;
 
-       return max;
+       *fres = fin / mxc_clkdivs[i];
+       return i;
 }
 
 /* MX1, MX31, MX35, MX51 CSPI */
@@ -589,9 +590,12 @@ static int mx21_config(struct spi_device *spi, struct spi_imx_config *config)
        struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
        unsigned int reg = MX21_CSPICTRL_ENABLE | MX21_CSPICTRL_MASTER;
        unsigned int max = is_imx27_cspi(spi_imx) ? 16 : 18;
+       unsigned int clk;
+
+       reg |= spi_imx_clkdiv_1(spi_imx->spi_clk, config->speed_hz, max, &clk)
+               << MX21_CSPICTRL_DR_SHIFT;
+       spi_imx->spi_bus_clk = clk;
 
-       reg |= spi_imx_clkdiv_1(spi_imx->spi_clk, config->speed_hz, max) <<
-               MX21_CSPICTRL_DR_SHIFT;
        reg |= config->bpw - 1;
 
        if (spi->mode & SPI_CPHA)