spi: spi-cadence-qspi: Disable STIG mode for Altera SoCFPGA.

STIG mode is enabled by default for less than 8 bytes data read/write.
STIG mode doesn't work with Altera SocFPGA platform due hardware
limitation.
Add a quirks to disable STIG mode for Altera SoCFPGA platform.

Signed-off-by: Niravkumar L Rabara <niravkumar.l.rabara@intel.com>
Link: https://patch.msgid.link/20241204063338.296959-1-niravkumar.l.rabara@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
index 0b45b7b..a031ecb 100644 (file)
--- a/drivers/spi/spi-cadence-quadspi.c
+++ b/drivers/spi/spi-cadence-quadspi.c
@@ -43,6 +43,7 @@ static_assert(CQSPI_MAX_CHIPSELECT <= SPI_CS_CNT_MAX);
 #define CQSPI_SLOW_SRAM                BIT(4)
 #define CQSPI_NEEDS_APB_AHB_HAZARD_WAR BIT(5)
 #define CQSPI_RD_NO_IRQ                        BIT(6)
+#define CQSPI_DISABLE_STIG_MODE                BIT(7)
 
 /* Capabilities */
 #define CQSPI_SUPPORTS_OCTAL           BIT(0)
@@ -103,6 +104,7 @@ struct cqspi_st {
        bool                    apb_ahb_hazard;
 
        bool                    is_jh7110; /* Flag for StarFive JH7110 SoC */
+       bool                    disable_stig_mode;
 
        const struct cqspi_driver_platdata *ddata;
 };
@@ -1416,7 +1418,8 @@ static int cqspi_mem_process(struct spi_mem *mem, const struct spi_mem_op *op)
         * reads, prefer STIG mode for such small reads.
         */
                if (!op->addr.nbytes ||
-                   op->data.nbytes <= CQSPI_STIG_DATA_LEN_MAX)
+                   (op->data.nbytes <= CQSPI_STIG_DATA_LEN_MAX &&
+                    !cqspi->disable_stig_mode))
                        return cqspi_command_read(f_pdata, op);
 
                return cqspi_read(f_pdata, op);
@@ -1880,6 +1883,8 @@ static int cqspi_probe(struct platform_device *pdev)
                        if (ret)
                                goto probe_reset_failed;
                }
+               if (ddata->quirks & CQSPI_DISABLE_STIG_MODE)
+                       cqspi->disable_stig_mode = true;
 
                if (of_device_is_compatible(pdev->dev.of_node,
                                            "xlnx,versal-ospi-1.0")) {
@@ -2043,7 +2048,8 @@ static const struct cqspi_driver_platdata intel_lgm_qspi = {
 static const struct cqspi_driver_platdata socfpga_qspi = {
        .quirks = CQSPI_DISABLE_DAC_MODE
                        | CQSPI_NO_SUPPORT_WR_COMPLETION
-                       | CQSPI_SLOW_SRAM,
+                       | CQSPI_SLOW_SRAM
+                       | CQSPI_DISABLE_STIG_MODE,
 };
 
 static const struct cqspi_driver_platdata versal_ospi = {