Switching between Serial Memory Mode (SMM) and (classic) SPI mode is a preparation for implementing .xfer() in the future.
Signed-off-by: Alexander Dahl ada@thorsis.com --- drivers/spi/atmel-quadspi.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/drivers/spi/atmel-quadspi.c b/drivers/spi/atmel-quadspi.c index 467f29c01ca..d29b5ab96e9 100644 --- a/drivers/spi/atmel-quadspi.c +++ b/drivers/spi/atmel-quadspi.c @@ -479,15 +479,19 @@ static bool atmel_qspi_supports_op(struct spi_slave *slave, }
/* - * If the QSPI controller is set in regular SPI mode, set it in - * Serial Memory Mode (SMM). + * Switch QSPI controller between regular SPI mode or Serial Memory Mode (SMM). */ -static int atmel_qspi_set_serial_memory_mode(struct atmel_qspi *aq) +static int atmel_qspi_set_serial_memory_mode(struct atmel_qspi *aq, + bool enable) { int ret = 0;
- if (!(aq->mr & QSPI_MR_SMM)) { - aq->mr |= QSPI_MR_SMM; + /* only write if designated state differs from current state */ + if (!!(aq->mr & QSPI_MR_SMM) != enable) { + if (enable) + aq->mr |= QSPI_MR_SMM; + else + aq->mr &= ~QSPI_MR_SMM; atmel_qspi_write(aq->mr, aq, QSPI_MR);
if (aq->caps->has_gclk) @@ -576,7 +580,7 @@ static int atmel_qspi_set_cfg(struct atmel_qspi *aq, ifr |= QSPI_IFR_TFRTYP_MEM; }
- mode = atmel_qspi_set_serial_memory_mode(aq); + mode = atmel_qspi_set_serial_memory_mode(aq, true); if (mode < 0) return mode;
@@ -683,7 +687,7 @@ static int atmel_qspi_sama7g5_set_cfg(struct atmel_qspi *aq, ifr |= QSPI_IFR_TFRTYP_MEM; }
- ret = atmel_qspi_set_serial_memory_mode(aq); + ret = atmel_qspi_set_serial_memory_mode(aq, true); if (ret < 0) return ret;
@@ -910,7 +914,7 @@ static int atmel_qspi_sama7g5_set_speed(struct udevice *bus, uint hz)
/* Set the QSPI controller by default in Serial Memory Mode */ aq->mr |= QSPI_MR_DQSDLYEN; - ret = atmel_qspi_set_serial_memory_mode(aq); + ret = atmel_qspi_set_serial_memory_mode(aq, true); if (ret < 0) return ret;