ssb: Add SPROM fallback support

This adds SSB functionality to register a fallback SPROM image from the
architecture setup code.

Weird architectures exist that have half-assed SSB devices without SPROM attached to
their PCI busses. The architecture can register a fallback SPROM image that is
used if no SPROM is found on the SSB device.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Cc: Florian Fainelli <florian@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 13 insertions, 1 deletions

diff --git a/drivers/ssb/pci.c b/drivers/ssb/pci.c
index c958ac16423..40ea4176224 100644
--- a/drivers/ssb/pci.c
+++ b/drivers/ssb/pci.c
@@ -564,6 +564,7 @@ static int sprom_extract(struct ssb_bus *bus, struct ssb_sprom *out,
 static int ssb_pci_sprom_get(struct ssb_bus *bus,
                              struct ssb_sprom *sprom)
 {
+        const struct ssb_sprom *fallback;
         int err = -ENOMEM;
         u16 *buf;
 
@@ -583,12 +584,23 @@ static int ssb_pci_sprom_get(struct ssb_bus *bus,
                 bus->sprom_size = SSB_SPROMSIZE_WORDS_R4;
                 sprom_do_read(bus, buf);
                 err = sprom_check_crc(buf, bus->sprom_size);
-                if (err)
+                if (err) {
+                        /* All CRC attempts failed.
+                         * Maybe there is no SPROM on the device?
+                         * If we have a fallback, use that. */
+                        fallback = ssb_get_fallback_sprom();
+                        if (fallback) {
+                                memcpy(sprom, fallback, sizeof(*sprom));
+                                err = 0;
+                                goto out_free;
+                        }
                         ssb_printk(KERN_WARNING PFX "WARNING: Invalid"
                                    " SPROM CRC (corrupt SPROM)\n");
+                }
         }
         err = sprom_extract(bus, sprom, buf, bus->sprom_size);
 
+out_free:
         kfree(buf);
 out:
         return err;