leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

spi: stm32-qspi: Always wait BUSY bit to be cleared in stm32_qspi_wait_cmd()

Browse Source 
In U-boot side, an issue has been encountered when QSPI source clock is
running at low frequency (24 MHz for example), waiting for TCF bit to be
set didn't ensure that all data has been send out the FIFO, we should also
wait that BUSY bit is cleared.

To prevent similar issue in kernel driver, we implement similar behavior
by always waiting BUSY bit to be cleared.

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Link: https://lore.kernel.org/r/20210603073421.8441-1-patrice.chotard@foss.st.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Patrice Chotard
2021-06-03 09:34:21 +02:00
committed by Mark Brown
parent f131767eef
commit d38fa9a155
1 changed files with 4 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/spi/spi-stm32-qspi.c
View File

@@ -294,7 +294,7 @@ static int stm32_qspi_wait_cmd(struct stm32_qspi *qspi,
int err = 0; int err = 0;
if (!op->data.nbytes) if (!op->data.nbytes)
return stm32_qspi_wait_nobusy(qspi); goto wait_nobusy;
if (readl_relaxed(qspi->io_base + QSPI_SR) & SR_TCF) if (readl_relaxed(qspi->io_base + QSPI_SR) & SR_TCF)
goto out; goto out;
@@ -315,6 +315,9 @@ static int stm32_qspi_wait_cmd(struct stm32_qspi *qspi,
out: out:
/* clear flags */ /* clear flags */
writel_relaxed(FCR_CTCF | FCR_CTEF, qspi->io_base + QSPI_FCR); writel_relaxed(FCR_CTCF | FCR_CTEF, qspi->io_base + QSPI_FCR);
wait_nobusy:
if (!err)
err = stm32_qspi_wait_nobusy(qspi);
return err; return err;
} }