fpga: altera-cvp: Fix registration for CvP incapable devices

The probe function needs to verify the CvP enable bit in order to
properly determine if FPGA Manager functionality can be safely
enabled.

Fixes: 34d1dc17ce97 ("fpga manager: Add Altera CvP driver")
Signed-off-by: Andreas Puhm <puhm@oregano.at>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Reviewed-by: Moritz Fischer <mdf@kernel.org>
Acked-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
index 144fa2a4d4cc..73950851e404 100644
--- a/drivers/fpga/altera-cvp.c
+++ b/drivers/fpga/altera-cvp.c
@@ -403,6 +403,7 @@ static int altera_cvp_probe(struct pci_dev *pdev,
         struct altera_cvp_conf *conf;
         struct fpga_manager *mgr;
         u16 cmd, val;
+        u32 regval;
         int ret;
 
         /*
@@ -416,6 +417,14 @@ static int altera_cvp_probe(struct pci_dev *pdev,
                 return -ENODEV;
         }
 
+        pci_read_config_dword(pdev, VSE_CVP_STATUS, &regval);
+        if (!(regval & VSE_CVP_STATUS_CVP_EN)) {
+                dev_err(&pdev->dev,
+                        "CVP is disabled for this device: CVP_STATUS Reg 0x%x\n",
+                        regval);
+                return -ENODEV;
+        }
+
         conf = devm_kzalloc(&pdev->dev, sizeof(*conf), GFP_KERNEL);
         if (!conf)
                 return -ENOMEM;