spi: imx: set spi_bus_clk for mx1, mx31 and mx35

Modify spi_imx_clkdiv_2() to return the resulting bus clock frequency
when the selected clock divider is applied. Set spi_imx->spi_bus_clk to
this frequency.

If spi_bus_clk is unset, spi_imx_calculate_timeout() causes a
division by 0.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 12 insertions, 5 deletions

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index f63cb30f9010..5cc72be30744 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -186,17 +186,19 @@ static unsigned int spi_imx_clkdiv_1(unsigned int fin,
 
 /* MX1, MX31, MX35, MX51 CSPI */
 static unsigned int spi_imx_clkdiv_2(unsigned int fin,
-                unsigned int fspi)
+                unsigned int fspi, unsigned int *fres)
 {
         int i, div = 4;
 
         for (i = 0; i < 7; i++) {
                 if (fspi * div >= fin)
-                        return i;
+                        goto out;
                 div <<= 1;
         }
 
-        return 7;
+out:
+        *fres = fin / div;
+        return i;
 }
 
 static int spi_imx_bytes_per_word(const int bpw)
@@ -482,9 +484,11 @@ static int mx31_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 = MX31_CSPICTRL_ENABLE | MX31_CSPICTRL_MASTER;
+        unsigned int clk;
 
-        reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz) <<
+        reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz, &clk) <<
                 MX31_CSPICTRL_DR_SHIFT;
+        spi_imx->spi_bus_clk = clk;
 
         if (is_imx35_cspi(spi_imx)) {
                 reg |= (config->bpw - 1) << MX35_CSPICTRL_BL_SHIFT;
@@ -625,9 +629,12 @@ static int mx1_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 = MX1_CSPICTRL_ENABLE | MX1_CSPICTRL_MASTER;
+        unsigned int clk;
 
-        reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz) <<
+        reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz, &clk) <<
                 MX1_CSPICTRL_DR_SHIFT;
+        spi_imx->spi_bus_clk = clk;
+
         reg |= config->bpw - 1;
 
         if (spi->mode & SPI_CPHA)