diff options
| author |   Tudor Ambarus <tudor.ambarus@microchip.com> | 2019-02-05 17:33:06 +0000 |
|---|---|---|
| committer |   Mark Brown <broonie@kernel.org> | 2019-02-06 17:16:41 +0000 |
| commit | 9958c8c39e58cfcc002053496c071abd305fe759 (patch) | |
| tree | e3aa565d7a1c4f620f0041f38cced7c1edd005ef /drivers/spi/atmel-quadspi.c | |
| parent | spi: spi-fsl-dspi: Provide support for DSPI slave mode operation (Vybryd vf610) (diff) | |
| download | linux-dev-9958c8c39e58cfcc002053496c071abd305fe759.tar.xz linux-dev-9958c8c39e58cfcc002053496c071abd305fe759.zip | |
spi: atmel-quadspi: cache MR value to avoid a write access
Set the controller by default in Serial Memory Mode (SMM) at probe.
Cache Mode Register (MR) value to avoid write access when setting
the controller in serial memory mode at exec_op().
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/atmel-quadspi.c')
| -rw-r--r-- | drivers/spi/atmel-quadspi.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/spi/atmel-quadspi.c b/drivers/spi/atmel-quadspi.c index ddc712410812..d6864d29f294 100644 --- a/drivers/spi/atmel-quadspi.c +++ b/drivers/spi/atmel-quadspi.c @@ -155,6 +155,7 @@ struct atmel_qspi { struct clk *clk; struct platform_device *pdev; u32 pending; + u32 mr; struct completion cmd_completion; }; @@ -238,7 +239,14 @@ static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op) icr = QSPI_ICR_INST(op->cmd.opcode); ifr = QSPI_IFR_INSTEN; - qspi_writel(aq, QSPI_MR, QSPI_MR_SMM); + /* + * If the QSPI controller is set in regular SPI mode, set it in + * Serial Memory Mode (SMM). + */ + if (aq->mr != QSPI_MR_SMM) { + qspi_writel(aq, QSPI_MR, QSPI_MR_SMM); + aq->mr = QSPI_MR_SMM; + } mode = find_mode(op); if (mode < 0) @@ -381,6 +389,10 @@ static int atmel_qspi_init(struct atmel_qspi *aq) /* Reset the QSPI controller */ qspi_writel(aq, QSPI_CR, QSPI_CR_SWRST); + /* Set the QSPI controller by default in Serial Memory Mode */ + qspi_writel(aq, QSPI_MR, QSPI_MR_SMM); + aq->mr = QSPI_MR_SMM; + /* Enable the QSPI controller */ qspi_writel(aq, QSPI_CR, QSPI_CR_QSPIEN); |