net: macb: Fix SUBNS increment and increase resolution

commit 7ad342bc58cc5197cd2f12a3c30b3949528c6d83 upstream.

The subns increment register has 24 bits as follows:
RegBit[15:0] = Subns[23:8]; RegBit[31:24] = Subns[7:0]

Fix the same in the driver and increase sub ns resolution to the
best capable, 24 bits. This should be the case on all GEM versions
that this PTP driver supports.

Signed-off-by: Harini Katakam <harini.katakam@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index 9bbaad9..efb44d5 100644 (file)
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -499,7 +499,11 @@
 
 /* Bitfields in TISUBN */
 #define GEM_SUBNSINCR_OFFSET                   0
-#define GEM_SUBNSINCR_SIZE                     16
+#define GEM_SUBNSINCRL_OFFSET                  24
+#define GEM_SUBNSINCRL_SIZE                    8
+#define GEM_SUBNSINCRH_OFFSET                  0
+#define GEM_SUBNSINCRH_SIZE                    16
+#define GEM_SUBNSINCR_SIZE                     24
 
 /* Bitfields in TI */
 #define GEM_NSINCR_OFFSET                      0

diff --git a/drivers/net/ethernet/cadence/macb_ptp.c b/drivers/net/ethernet/cadence/macb_ptp.c
index a6dc47e..8f912de 100644 (file)
--- a/drivers/net/ethernet/cadence/macb_ptp.c
+++ b/drivers/net/ethernet/cadence/macb_ptp.c
@@ -115,7 +115,10 @@ static int gem_tsu_incr_set(struct macb *bp, struct tsu_incr *incr_spec)
         * to take effect.
         */
        spin_lock_irqsave(&bp->tsu_clk_lock, flags);
-       gem_writel(bp, TISUBN, GEM_BF(SUBNSINCR, incr_spec->sub_ns));
+       /* RegBit[15:0] = Subns[23:8]; RegBit[31:24] = Subns[7:0] */
+       gem_writel(bp, TISUBN, GEM_BF(SUBNSINCRL, incr_spec->sub_ns) |
+                  GEM_BF(SUBNSINCRH, (incr_spec->sub_ns >>
+                         GEM_SUBNSINCRL_SIZE)));
        gem_writel(bp, TI, GEM_BF(NSINCR, incr_spec->ns));
        spin_unlock_irqrestore(&bp->tsu_clk_lock, flags);