2016-11-01 21:19:05

by Robert Baldyga

[permalink] [raw]
Subject: [PATCH] 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 <[email protected]>
---
drivers/spi/spi-imx.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index deb782f..088828c 100644
--- 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 */
@@ -574,9 +575,12 @@ 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)
--
2.7.4