firewire: add CSR CYCLE_TIME write support

The specification requires that CYCLE_TIME is writable so that it can be
initialized, so we better implement it.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

2 files changed, 10 insertions, 0 deletions

diff --git a/drivers/firewire/core-transaction.c b/drivers/firewire/core-transaction.c
index 9a7d3ec23f2b..e3925f67ec12 100644
--- a/drivers/firewire/core-transaction.c
+++ b/drivers/firewire/core-transaction.c
@@ -1097,6 +1097,9 @@ static void handle_registers(struct fw_card *card, struct fw_request *request,
                 if (TCODE_IS_READ_REQUEST(tcode) && length == 4)
                         *data = cpu_to_be32(card->driver->
                                         read_csr_reg(card, CSR_CYCLE_TIME));
+                else if (tcode == TCODE_WRITE_QUADLET_REQUEST)
+                        card->driver->write_csr_reg(card, CSR_CYCLE_TIME,
+                                                    be32_to_cpu(*data));
                 else
                         rcode = RCODE_TYPE_ERROR;
                 break;
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index a55fbbce9e79..777811a736b2 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -1996,6 +1996,13 @@ static void ohci_write_csr_reg(struct fw_card *card, int csr_offset, u32 value)
                 flush_writes(ohci);
                 break;
 
+        case CSR_CYCLE_TIME:
+                reg_write(ohci, OHCI1394_IsochronousCycleTimer, value);
+                reg_write(ohci, OHCI1394_IntEventSet,
+                          OHCI1394_cycleInconsistent);
+                flush_writes(ohci);
+                break;
+
         default:
                 WARN_ON(1);
                 break;