From: Fabio Estevam fabio.estevam@freescale.com
Registers HW_PINCTRL_DRIVE9, HW_PINCTRL_DRIVE10, HW_PINCTRL_DRIVE11, HW_PINCTRL_DRIVE12, HW_PINCTRL_DRIVE13 and HW_PINCTRL_DRIVE14 control the drive strength and the voltage selection for the DDR pins.
The reset values of the voltage selection pins are '1', which is marked as 'reserved' in the mx23 reference manual.
Clear these bits for proper operation of DDR.
Also change MUX_CONFIG_EMI, which results in better stability and match the bootlets code from Freescale.
Signed-off-by: Fabio Estevam fabio.estevam@freescale.com --- board/olimex/mx23_olinuxino/spl_boot.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/board/olimex/mx23_olinuxino/spl_boot.c b/board/olimex/mx23_olinuxino/spl_boot.c index a96c293..5a43677 100644 --- a/board/olimex/mx23_olinuxino/spl_boot.c +++ b/board/olimex/mx23_olinuxino/spl_boot.c @@ -30,7 +30,7 @@ #include <asm/arch/sys_proto.h>
#define MUX_CONFIG_EMI (MXS_PAD_3V3 | MXS_PAD_16MA | MXS_PAD_PULLUP) -#define MUX_CONFIG_SSP (MXS_PAD_3V3 | MXS_PAD_8MA | MXS_PAD_PULLUP) +#define MUX_CONFIG_SSP MXS_PAD_12MA
const iomux_cfg_t iomux_setup[] = { /* DUART */ @@ -103,5 +103,16 @@ const iomux_cfg_t iomux_setup[] = {
void board_init_ll(void) { + struct mxs_pinctrl_regs *pinctrl = + (struct mxs_pinctrl_regs *)MXS_PINCTRL_BASE; + + /* Clear the voltage bits for EMI pins as the reset value is invalid */ + writel(0, &pinctrl->drive9); + writel(0, &pinctrl->drive10); + writel(0, &pinctrl->drive11); + writel(0, &pinctrl->drive12); + writel(0, &pinctrl->drive13); + writel(0, &pinctrl->drive14); + writel(0, &pinctrl->drive9); mxs_common_spl_init(iomux_setup, ARRAY_SIZE(iomux_setup)); }