parport_pc: Add an ECR mask field for PCI devices

Add a bitmask field specifying writable ECR bits for PCI devices and
apply it via `__parport_pc_probe_port'.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Link: https://lore.kernel.org/r/20230108215656.6433-5-sudipm.mukherjee@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/parport/parport_pc.c b/drivers/parport/parport_pc.c
index 2928f36..d7e64f6 100644 (file)
--- a/drivers/parport/parport_pc.c
+++ b/drivers/parport/parport_pc.c
@@ -2662,6 +2662,10 @@ static struct parport_pc_pci {
        /* Bit field of parport modes to exclude. */
        unsigned int mode_mask;
 
+       /* If non-zero, sets the bitmask of writable ECR bits.  In that
+        * case additionally bit 0 will be forcibly set on writes. */
+       unsigned char ecr_writable;
+
        /* If set, this is called immediately after pci_enable_device.
         * If it returns non-zero, no probing will take place and the
         * ports will not be used. */
@@ -2868,7 +2872,8 @@ static int parport_pc_pci_probe(struct pci_dev *dev,
                        __parport_pc_probe_port(io_lo, io_hi, irq,
                                                PARPORT_DMA_NONE, &dev->dev,
                                                IRQF_SHARED,
-                                               cards[i].mode_mask, 0);
+                                               cards[i].mode_mask,
+                                               cards[i].ecr_writable);
                if (data->ports[count])
                        count++;
        }