ENGR00308399 mtd: fsl-quadspi: quit if the M4 is using the quadspi

Detect if the quadspi is used by the M4.
If the M4 does use it, we quit.

Signed-off-by: Huang Shijie <b32955@freescale.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
index 4f8bc62761d6..091b2ed99f86 100644
--- a/drivers/mtd/spi-nor/fsl-quadspi.c
+++ b/drivers/mtd/spi-nor/fsl-quadspi.c
@@ -882,6 +882,13 @@ static void fsl_qspi_unprep(struct spi_nor *nor, enum spi_nor_ops ops)
         clk_disable(q->clk_en);
 }
 
+/* If the uboot enable the M4 to use the Quadspi, we should quit. */
+static bool fsl_m4_is_using(struct fsl_qspi *q)
+{
+        return (readl(q->iobase + QUADSPI_BUF0CR) ==
+                        QUADSPI_BUFXCR_INVALID_MSTRID);
+}
+
 static int fsl_qspi_probe(struct platform_device *pdev)
 {
         struct device_node *np = pdev->dev.of_node;
@@ -948,6 +955,12 @@ static int fsl_qspi_probe(struct platform_device *pdev)
                 goto map_failed;
         }
 
+        if (fsl_m4_is_using(q)) {
+                dev_info(dev, "The M4 is using quadspi controller, we quit.\n");
+                ret = -EINVAL;
+                goto irq_failed;
+        }
+
         /* find the irq */
         ret = platform_get_irq(pdev, 0);
         if (ret < 0) {