[PATCH u-boot-marvell 1/4] arm: mvebu: turris_mox: Fix early SPI communication

Marek Behún marek.behun at nic.cz
Mon Mar 30 19:19:23 CEST 2020


The SPI clock signal changes value when the SPI configuration register
is configured. This can sometimes lead to the device misinterpreting
the enablement of the SPI controller as actual clock tick.
This can be solved by first setting the SPI CS1 pin from GPIO to SPI mode,
and only after that writing the SPI configuration register.

Signed-off-by: Marek Behún <marek.behun at nic.cz>
---
 board/CZ.NIC/turris_mox/turris_mox.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/board/CZ.NIC/turris_mox/turris_mox.c b/board/CZ.NIC/turris_mox/turris_mox.c
index 377191baef..7118096f32 100644
--- a/board/CZ.NIC/turris_mox/turris_mox.c
+++ b/board/CZ.NIC/turris_mox/turris_mox.c
@@ -67,9 +67,9 @@ int board_fix_fdt(void *blob)
 	 * to read SPI by reading/writing SPI registers directly
 	 */
 
-	writel(0x563fa, ARMADA_37XX_NB_GPIO_SEL);
 	writel(0x10df, ARMADA_37XX_SPI_CFG);
-	writel(0x2005b, ARMADA_37XX_SPI_CTRL);
+	clrbits_le32(ARMADA_37XX_NB_GPIO_SEL, BIT(12));
+	setbits_le32(ARMADA_37XX_SPI_CTRL, BIT(17));
 
 	while (!(readl(ARMADA_37XX_SPI_CTRL) & 0x2))
 		udelay(1);
@@ -89,7 +89,7 @@ int board_fix_fdt(void *blob)
 
 	size = i;
 
-	writel(0x5b, ARMADA_37XX_SPI_CTRL);
+	clrbits_le32(ARMADA_37XX_SPI_CTRL, BIT(17));
 
 	if (size > 1 && (topology[1] == MOX_MODULE_PCI ||
 			 topology[1] == MOX_MODULE_USB3 ||
-- 
2.24.1



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