arm: mvebu: turris_mox: Fix unstable board topology reading

The pre-relocation board topology reading in board_fix_fdt() is
unstable: sometimes wrong data are read from the SPI bus.

This is due to wrong order of SPI bus configuration instructions: we
first need to set the pins to SPI mode, and only after that configure
the bus.

Also add a 1ms delay before enabling chip-select, so that the clock pin
is high for some time before reading the bus.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>
This commit is contained in:
Marek Behún
2021-11-26 14:57:14 +01:00
committed by Stefan Roese
parent d368e10705
commit 08370038df

View File

@@ -56,9 +56,11 @@ int board_fix_fdt(void *blob)
* to read SPI by reading/writing SPI registers directly
*/
writel(0x10df, ARMADA_37XX_SPI_CFG);
/* put pin from GPIO to SPI mode */
clrbits_le32(ARMADA_37XX_NB_GPIO_SEL, BIT(12));
/* configure cpol, cpha, prescale */
writel(0x10df, ARMADA_37XX_SPI_CFG);
mdelay(1);
/* enable SPI CS1 */
setbits_le32(ARMADA_37XX_SPI_CTRL, BIT(17));