can: ifi: Check core revision upon probe

Older versions of the core are not compatible with the driver due
to various intrusive fixes of the core. Read out the VER register,
check the core revision bitfield and verify if the core in use is
new enough (rev 2.1 or newer) to work correctly with this driver.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Heiko Schocher <hs@denx.de>
Cc: Markus Marb <markus@marb.org>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 10 insertions, 1 deletions

diff --git a/drivers/net/can/ifi_canfd/ifi_canfd.c b/drivers/net/can/ifi_canfd/ifi_canfd.c
index 2772d05ff11c..9fd396c3569a 100644
--- a/drivers/net/can/ifi_canfd/ifi_canfd.c
+++ b/drivers/net/can/ifi_canfd/ifi_canfd.c
@@ -136,6 +136,8 @@
 #define IFI_CANFD_SYSCLOCK                      0x50
 
 #define IFI_CANFD_VER                           0x54
+#define IFI_CANFD_VER_REV_MASK                  0xff
+#define IFI_CANFD_VER_REV_MIN_SUPPORTED         0x15
 
 #define IFI_CANFD_IP_ID                         0x58
 #define IFI_CANFD_IP_ID_VALUE                   0xD073CAFD
@@ -933,7 +935,7 @@ static int ifi_canfd_plat_probe(struct platform_device *pdev)
         struct resource *res;
         void __iomem *addr;
         int irq, ret;
-        u32 id;
+        u32 id, rev;
 
         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
         addr = devm_ioremap_resource(dev, res);
@@ -947,6 +949,13 @@ static int ifi_canfd_plat_probe(struct platform_device *pdev)
                 return -EINVAL;
         }
 
+        rev = readl(addr + IFI_CANFD_VER) & IFI_CANFD_VER_REV_MASK;
+        if (rev < IFI_CANFD_VER_REV_MIN_SUPPORTED) {
+                dev_err(dev, "This block is too old (rev %i), minimum supported is rev %i\n",
+                        rev, IFI_CANFD_VER_REV_MIN_SUPPORTED);
+                return -EINVAL;
+        }
+
         ndev = alloc_candev(sizeof(*priv), 1);
         if (!ndev)
                 return -ENOMEM;