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. [ 90.356106] Division by zero in kernel. [ 90.362631] CPU: 0 PID: 130 Comm: spidev_test Not tainted 4.8.0-rc3-next-20160825+ #105 [ 90.372461] Hardware name: Freescale i.MX25 (Device Tree Support) [ 90.378708] Backtrace: [...] [ 90.409251] [<c000dda0>] (__div0) from [<c0175b3c>] (Ldiv0+0x8/0x10) [ 90.415783] [<bf007c8c>] (spi_imx_calculate_timeout [spi_imx]) from [<bf007ee8>] (spi_imx_transfer+0x220/0x278 [spi_imx]) [ 90.426924] [<bf007cc8>] (spi_imx_transfer [spi_imx]) from [<c01f1560>] (spi_bitbang_transfer_one+0x60/0x8c) [ 90.436864] r8:d3ad52c8 r7:d3ad5800 r6:d3ad5000 r5:d3ae4f40 r4:00000000 [ 90.443737] [<c01f1500>] (spi_bitbang_transfer_one) from [<c01edcb0>] (spi_transfer_one_message+0x12c/0x37c) [ 90.453668] r8:c0a530e4 r7:d3ad5178 r6:d3ad5800 r5:d3ad5000 r4:d3b13e88 r3:00000000 [ 90.461633] [<c01edb84>] (spi_transfer_one_message) from [<c01ee428>] (__spi_pump_messages+0x528/0x568) Signed-off-by: Martin Kaiser <[email protected]> --- drivers/spi/spi-imx.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index f63cb30..5cc72be 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) -- 1.7.10.4
