[PATCH v8 2/6] spi: cadence-quadspi: Disable the DAC for Intel LGM SoC

From: Ramuthevar,Vadivel MuruganX
Date: Thu Nov 19 2020 - 00:56:13 EST


From: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>

On Intel Lightning Mountain(LGM) SoCs QSPI controller do not use
Direct Access Controller(DAC).

This patch adds a quirk to disable the Direct Access Controller
for data transfer instead it uses indirect data transfe

DAC bit resets to 1 so there is no need to explicitly set it.

Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>
---
drivers/spi/spi-cadence-quadspi.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
index d7b10c46fa70..d12b765e87be 100644
--- a/drivers/spi/spi-cadence-quadspi.c
+++ b/drivers/spi/spi-cadence-quadspi.c
@@ -1101,10 +1101,12 @@ static void cqspi_controller_init(struct cqspi_st *cqspi)
writel(cqspi->fifo_depth * cqspi->fifo_width / 8,
cqspi->iobase + CQSPI_REG_INDIRECTWRWATERMARK);

- /* Enable Direct Access Controller */
- reg = readl(cqspi->iobase + CQSPI_REG_CONFIG);
- reg |= CQSPI_REG_CONFIG_ENB_DIR_ACC_CTRL;
- writel(reg, cqspi->iobase + CQSPI_REG_CONFIG);
+ /* Disable direct access controller */
+ if (!cqspi->use_direct_mode) {
+ reg = readl(cqspi->iobase + CQSPI_REG_CONFIG);
+ reg &= ~CQSPI_REG_CONFIG_ENB_DIR_ACC_CTRL;
+ writel(reg, cqspi->iobase + CQSPI_REG_CONFIG);
+ }

cqspi_controller_enable(cqspi, 1);
}
@@ -1388,6 +1390,10 @@ static const struct cqspi_driver_platdata am654_ospi = {
.quirks = CQSPI_NEEDS_WR_DELAY,
};

+static const struct cqspi_driver_platdata intel_lgm_qspi = {
+ .quirks = CQSPI_DISABLE_DAC_MODE,
+};
+
static const struct of_device_id cqspi_dt_ids[] = {
{
.compatible = "cdns,qspi-nor",
@@ -1403,6 +1409,7 @@ static const struct of_device_id cqspi_dt_ids[] = {
},
{
.compatible = "intel,lgm-qspi",
+ .data = &intel_lgm_qspi,
},
{ /* end of table */ }
};
--
2.11.0