From 857db48e5f6372eead8a32469d981801e775ee48 Mon Sep 17 00:00:00 2001
From: Vignesh R <vigneshr@ti.com>
Date: Tue, 10 Nov 2015 11:52:10 +0530
Subject: [PATCH] spi: ti_qspi: Add dummy readl for bus sync

Add dummy readl after invalidating cmd field of QSPI_CMD_REG to ensure
bus sync. Without this device's CS is not deactivated reliably leading
to failure to enumerate flash or failure to set quad enable bit on
Macronix flash present on am437x-sk and am437x-idk evms.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Reviewed-by: Mugunthan V N <mugunthanvnm@ti.com>
Reviewed-by: Jagan Teki <jteki@openedev.com>
---
 drivers/spi/ti_qspi.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/spi/ti_qspi.c b/drivers/spi/ti_qspi.c
index ecd9d78ae3..646dd899d3 100644
--- a/drivers/spi/ti_qspi.c
+++ b/drivers/spi/ti_qspi.c
@@ -170,6 +170,8 @@ void spi_cs_deactivate(struct spi_slave *slave)
 	debug("spi_cs_deactivate: 0x%08x\n", (u32)slave);
 
 	writel(qslave->cmd | QSPI_INVAL, &qslave->base->cmd);
+	/* dummy readl to ensure bus sync */
+	readl(&qslave->base->cmd);
 }
 
 void spi_init(void)
-- 
2.39.5