Once the start bit is toggled it takes a small amount of time before it is internally synchronized. This means we can't start writing during that part. So add a small delay to allow the bit to be synchronized.
Signed-off-by: Pratyush Yadav p.yadav@ti.com --- drivers/spi/cadence_qspi.c | 4 ++++ drivers/spi/cadence_qspi.h | 1 + drivers/spi/cadence_qspi_apb.c | 6 ++++++ 3 files changed, 11 insertions(+)
diff --git a/drivers/spi/cadence_qspi.c b/drivers/spi/cadence_qspi.c index de7628de27..a961193cdc 100644 --- a/drivers/spi/cadence_qspi.c +++ b/drivers/spi/cadence_qspi.c @@ -20,6 +20,8 @@ #include <linux/sizes.h> #include "cadence_qspi.h"
+#define NSEC_PER_SEC 1000000000L + #define CQSPI_STIG_READ 0 #define CQSPI_STIG_WRITE 1 #define CQSPI_READ 2 @@ -208,6 +210,8 @@ static int cadence_spi_probe(struct udevice *bus) priv->qspi_is_init = 1; }
+ plat->wr_delay = 50 * DIV_ROUND_UP(NSEC_PER_SEC, plat->ref_clk_hz); + return 0; }
diff --git a/drivers/spi/cadence_qspi.h b/drivers/spi/cadence_qspi.h index b06d7750e2..5c745541a6 100644 --- a/drivers/spi/cadence_qspi.h +++ b/drivers/spi/cadence_qspi.h @@ -27,6 +27,7 @@ struct cadence_spi_plat { fdt_addr_t ahbsize; bool use_dac_mode; int read_delay; + u32 wr_delay;
/* Flash parameters */ u32 page_size; diff --git a/drivers/spi/cadence_qspi_apb.c b/drivers/spi/cadence_qspi_apb.c index b051f462ed..92e57730bd 100644 --- a/drivers/spi/cadence_qspi_apb.c +++ b/drivers/spi/cadence_qspi_apb.c @@ -730,6 +730,12 @@ cadence_qspi_apb_indirect_write_execute(struct cadence_spi_plat *plat, writel(CQSPI_REG_INDIRECTWR_START, plat->regbase + CQSPI_REG_INDIRECTWR);
+ /* + * Some delay is required for the above bit to be internally + * synchronized by the QSPI module. + */ + ndelay(plat->wr_delay); + while (remaining > 0) { write_bytes = remaining > page_size ? page_size : remaining; writesl(plat->ahbbase, bb_txbuf, write_bytes >> 2);