spi: atmel-quadspi: fix resume call

When waking up from the Suspend-to-RAM state, the following error
was seen:

m25p80 spi2.0: flash operation timed out

The flash remained in an undefined state, returning 0xFFs.
Fix it by setting the Serial Clock Baud Rate, as it was set
before the conversion to SPIMEM.

Tested with sama5d2_xplained and mx25l25673g spi-nor in
Backup + Self-Refresh and Suspend modes.

Fixes: 0e6aae08e9ae ("spi: Add QuadSPI driver for Atmel SAMA5D2")
Reported-by: Mark Deneen <mdeneen@gmail.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/atmel-quadspi.c b/drivers/spi/atmel-quadspi.c
index 32eb744..6a7d7b5 100644 (file)
--- a/drivers/spi/atmel-quadspi.c
+++ b/drivers/spi/atmel-quadspi.c
@@ -151,6 +151,7 @@ struct atmel_qspi {
        const struct atmel_qspi_caps *caps;
        u32                     pending;
        u32                     mr;
+       u32                     scr;
        struct completion       cmd_completion;
 };
 
@@ -382,7 +383,7 @@ static int atmel_qspi_setup(struct spi_device *spi)
        struct spi_controller *ctrl = spi->master;
        struct atmel_qspi *aq = spi_controller_get_devdata(ctrl);
        unsigned long src_rate;
-       u32 scr, scbr;
+       u32 scbr;
 
        if (ctrl->busy)
                return -EBUSY;
@@ -399,8 +400,8 @@ static int atmel_qspi_setup(struct spi_device *spi)
        if (scbr > 0)
                scbr--;
 
-       scr = QSPI_SCR_SCBR(scbr);
-       writel_relaxed(scr, aq->regs + QSPI_SCR);
+       aq->scr = QSPI_SCR_SCBR(scbr);
+       writel_relaxed(aq->scr, aq->regs + QSPI_SCR);
 
        return 0;
 }
@@ -584,6 +585,9 @@ static int __maybe_unused atmel_qspi_resume(struct device *dev)
        clk_prepare_enable(aq->qspick);
 
        atmel_qspi_init(aq);
+
+       writel_relaxed(aq->scr, aq->regs + QSPI_SCR);
+
        return 0;
 }