[PATCH 4.14 180/209] net: macb: Fix SUBNS increment and increase resolution

Greg Kroah-Hartman
2019-12-04T18:08:37Z

From: Harini Katakam <harini.katakam@xilinx.com>

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>

---
drivers/net/ethernet/cadence/macb.h | 6 +++++-
drivers/net/ethernet/cadence/macb_ptp.c | 5 ++++-
2 files changed, 9 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -457,7 +457,11 @@

/* 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
--- 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
* 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);