firewire: add read_csr_reg driver callback

To prepare for the following additions of more OHCI-implemented CSR
registers, replace the get_cycle_time driver callback with a generic
CSR register callback.

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

1 files changed, 16 insertions, 3 deletions

diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 65b9bdb8541a..a8093a9a3fc8 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -1939,9 +1939,8 @@ static u32 cycle_timer_ticks(u32 cycle_timer)
  * error.  (A PCI read should take at least 20 ticks of the 24.576 MHz timer to
  * execute, so we have enough precision to compute the ratio of the differences.)
  */
-static u32 ohci_get_cycle_time(struct fw_card *card)
+static u32 get_cycle_time(struct fw_ohci *ohci)
 {
-        struct fw_ohci *ohci = fw_ohci(card);
         u32 c0, c1, c2;
         u32 t0, t1, t2;
         s32 diff01, diff12;
@@ -1970,6 +1969,20 @@ static u32 ohci_get_cycle_time(struct fw_card *card)
         return c2;
 }
 
+static u32 ohci_read_csr_reg(struct fw_card *card, int csr_offset)
+{
+        struct fw_ohci *ohci = fw_ohci(card);
+
+        switch (csr_offset) {
+        case CSR_CYCLE_TIME:
+                return get_cycle_time(ohci);
+
+        default:
+                WARN_ON(1);
+                return 0;
+        }
+}
+
 static void copy_iso_headers(struct iso_context *ctx, void *p)
 {
         int i = ctx->header_length;
@@ -2407,7 +2420,7 @@ static const struct fw_card_driver ohci_driver = {
         .send_response          = ohci_send_response,
         .cancel_packet          = ohci_cancel_packet,
         .enable_phys_dma        = ohci_enable_phys_dma,
-        .get_cycle_time         = ohci_get_cycle_time,
+        .read_csr_reg           = ohci_read_csr_reg,
 
         .allocate_iso_context   = ohci_allocate_iso_context,
         .free_iso_context       = ohci_free_iso_context,