On 10 November 2015 at 11:52, Vignesh R vigneshr@ti.com wrote:
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
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 bd63db8a2acc..ba2da017c21a 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);
Isn't effect anything for non-quad case? and dummy bytes might changed based on quad and quadio does this single dummy readl is same for those cases as well?
thanks!