[U-Boot] [PATCH] spi: cadence_qspi_apb: fix QSPI write issues

[Ooi, Joyce]

From: Chee Hong Ang <chee.hong.ang at intel.com>

QSPI driver perform chip select on every flash read/write
access. The driver need to disable/enable the QSPI controller
while performing chip select. This may cause some data lost
especially the QSPI controller is configured to run at slower
speed as it may take longer time to access the flash device.
This patch prevent the driver from disable/enable the QSPI
controller too soon and inadvertently halting any ongoing flash
read/write access by ensuring the QSPI controller is always in
idle mode after each read/write access.

Signed-off-by: Chee Hong Ang <chee.hong.ang at intel.com>
Signed-off-by: Ooi, Joyce <joyce.ooi at intel.com>
---
 drivers/spi/cadence_qspi_apb.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/spi/cadence_qspi_apb.c b/drivers/spi/cadence_qspi_apb.c
index 55a7501..ab14a5f 100644
--- a/drivers/spi/cadence_qspi_apb.c
+++ b/drivers/spi/cadence_qspi_apb.c
@@ -676,6 +676,10 @@ int cadence_qspi_apb_indirect_read_execute(struct cadence_spi_platdata *plat,
 	writel(CQSPI_REG_INDIRECTRD_DONE,
 	       plat->regbase + CQSPI_REG_INDIRECTRD);
 
+	/* Wait til QSPI is idle */
+	if (!cadence_qspi_wait_idle(plat->regbase))
+		return -EIO;
+
 	return 0;
 
 failrd:
@@ -782,6 +786,11 @@ int cadence_qspi_apb_indirect_write_execute(struct cadence_spi_platdata *plat,
 	       plat->regbase + CQSPI_REG_INDIRECTWR);
 	if (bounce_buf)
 		free(bounce_buf);
+
+	/* Wait til QSPI is idle */
+	if (!cadence_qspi_wait_idle(plat->regbase))
+		return -EIO;
+
 	return 0;
 
 failwr:
-- 
1.9.1