[PATCH v2 4/6] mtd: nand: pxa3xx: Enable devbus/nand arbiter on Armada 8K

[Chris Packham]

The CN9130 SoC (an ARMADA 8K type) has both a NAND Flash Controller and
a generic local bus controller (Device Bus Controller) that share common
pins.

With a board design that incorporates both a NAND flash and uses
the Device Bus (in our case for an SRAM) accessing the Device Bus device
fails unless the NfArbiterEn bit is set. Setting the bit enables
arbitration between the Device Bus and the NAND flash.

Since there is no obvious downside in enabling this for designs that
don't require arbitration, we always enable it.

Signed-off-by: Chris Packham <judge.packham at gmail.com>
---
 drivers/mtd/nand/raw/pxa3xx_nand.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/raw/pxa3xx_nand.c b/drivers/mtd/nand/raw/pxa3xx_nand.c
index 9dee580ab9c2..d502e967f92c 100644
--- a/drivers/mtd/nand/raw/pxa3xx_nand.c
+++ b/drivers/mtd/nand/raw/pxa3xx_nand.c
@@ -125,6 +125,7 @@ DECLARE_GLOBAL_DATA_PTR;
 /* System control register and bit to enable NAND on some SoCs */
 #define GENCONF_SOC_DEVICE_MUX	0x208
 #define GENCONF_SOC_DEVICE_MUX_NFC_EN BIT(0)
+#define GENCONF_SOC_DEVICE_MUX_NFC_DEVBUS_ARB_EN BIT(27)
 
 /*
  * This should be large enough to read 'ONFI' and 'JEDEC'.
@@ -1739,7 +1740,7 @@ static int alloc_nand_resource(struct udevice *dev, struct pxa3xx_nand_info *inf
 			return PTR_ERR(sysctrl_base);
 
 		regmap_read(sysctrl_base, GENCONF_SOC_DEVICE_MUX, &reg);
-		reg |= GENCONF_SOC_DEVICE_MUX_NFC_EN;
+		reg |= GENCONF_SOC_DEVICE_MUX_NFC_EN | GENCONF_SOC_DEVICE_MUX_NFC_DEVBUS_ARB_EN;
 		regmap_write(sysctrl_base, GENCONF_SOC_DEVICE_MUX, reg);
 	}
 
-- 
2.41.0