Re: [PATCH v3 2/3] mtd: spi-nor: cadence-quadspi: Disable the DAC for Intel LGM SoC

From: Ramuthevar, Vadivel MuruganX
Date: Wed Oct 16 2019 - 04:48:23 EST


Hi Vignesh,

ÂÂÂÂÂ Thank you for the review comments.

On 16/10/2019 4:32 PM, Vignesh Raghavendra wrote:

On 09/09/19 4:17 PM, Ramuthevar,Vadivel MuruganX wrote:
From: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>

on Intel's Lightning Mountain(LGM) SoCs QSPI controller do not use
s/on/On
Agreed, will update.
Direct Access Controller(DAC).

This patch introduces to properly disable the Direct Access Controller
"This patch adds a quirk to disable..." or something something similar
okay, will update.
for data transfer instead it uses indirect data transfer.

Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>
---
drivers/mtd/spi-nor/Kconfig | 2 +-
drivers/mtd/spi-nor/cadence-quadspi.c | 21 +++++++++++++++++++++
2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig
index 6de83277ce8b..ba2e372ae514 100644
--- a/drivers/mtd/spi-nor/Kconfig
+++ b/drivers/mtd/spi-nor/Kconfig
@@ -34,7 +34,7 @@ config SPI_ASPEED_SMC
config SPI_CADENCE_QUADSPI
tristate "Cadence Quad SPI controller"
- depends on OF && (ARM || ARM64 || COMPILE_TEST)
+ depends on OF && (ARM || ARM64 || COMPILE_TEST || X86)
help
Enable support for the Cadence Quad SPI Flash controller.
diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
index 67f15a1f16fd..73b9fbd1508a 100644
--- a/drivers/mtd/spi-nor/cadence-quadspi.c
+++ b/drivers/mtd/spi-nor/cadence-quadspi.c
@@ -33,6 +33,7 @@
/* Quirks */
#define CQSPI_NEEDS_WR_DELAY BIT(0)
+#define CQSPI_DISABLE_DAC_MODE BIT(1)
/* Capabilities mask */
#define CQSPI_BASE_HWCAPS_MASK \
@@ -609,6 +610,13 @@ static int cqspi_write_setup(struct spi_nor *nor)
struct cqspi_st *cqspi = f_pdata->cqspi;
void __iomem *reg_base = cqspi->iobase;
+ /* Disable direct access controller */
+ if (!f_pdata->use_direct_mode) {
+ reg = readl(reg_base + CQSPI_REG_CONFIG);
+ reg &= ~CQSPI_REG_CONFIG_ENB_DIR_ACC_CTRL;
+ writel(reg, reg_base + CQSPI_REG_CONFIG);
+ }
+
/* Set opcode. */
reg = nor->program_opcode << CQSPI_REG_WR_INSTR_OPCODE_LSB;
writel(reg, reg_base + CQSPI_REG_WR_INSTR);
@@ -1328,6 +1336,7 @@ static int cqspi_probe(struct platform_device *pdev)
struct resource *res_ahb;
struct reset_control *rstc, *rstc_ocp;
const struct cqspi_driver_platdata *ddata;
+ struct cqspi_flash_pdata *f_pdata;
int ret;
int irq;
@@ -1436,6 +1445,9 @@ static int cqspi_probe(struct platform_device *pdev)
goto probe_setup_failed;
}
+ if (ddata && (ddata->quirks & CQSPI_DISABLE_DAC_MODE))
+ f_pdata->use_direct_mode = false;
+
If you do this here, you will still end up acquiring a DMA channel in
cqspi_request_mmap_dma() (called from cqspi_setup_flash()). So, please
move the check to cqspi_setup_flash().

will fix it.

---
Regards
Vadivel
return ret;
probe_setup_failed:
cqspi_controller_enable(cqspi, 0);
@@ -1510,6 +1522,11 @@ static const struct cqspi_driver_platdata am654_ospi = {
.quirks = CQSPI_NEEDS_WR_DELAY,
};
+static const struct cqspi_driver_platdata intel_lgm_qspi = {
+ .hwcaps_mask = CQSPI_BASE_HWCAPS_MASK,
+ .quirks = CQSPI_DISABLE_DAC_MODE,
+};
+
static const struct of_device_id cqspi_dt_ids[] = {
{
.compatible = "cdns,qspi-nor",
@@ -1523,6 +1540,10 @@ static const struct of_device_id cqspi_dt_ids[] = {
.compatible = "ti,am654-ospi",
.data = &am654_ospi,
},
+ {
+ .compatible = "intel,lgm-qspi",
+ .data = &intel_lgm_qspi,
+ },
{ /* end of table */ }
};