[PATCH net-next 1/2] ravb: Add tx and rx clock internal delays mode of APSR

[Simon Horman]

From: Kazuya Mizuguchi <kazuya.mizuguchi...@renesas.com>

This patch enables tx and rx clock internal delay modes (TDM and RDM).

This is to address a failure in the case of 1Gbps communication using the
by salvator-x board with the KSZ9031RNX phy. This has been reported to
occur with both the r8a7795 (H3) and r8a7796 (M3-W) SoCs.

With this change APSR internal delay modes are enabled for
"rgmii-id", "rgmii-rxid" and "rgmii-txid" phy modes as follows:

phy mode   | ASPR delay mode
-----------+----------------
rgmii-id   | TDM and RDM
rgmii-rxid | RDM
rgmii-txid | TDM

Signed-off-by: Kazuya Mizuguchi <kazuya.mizuguchi...@renesas.com>
Signed-off-by: Simon Horman <horms+rene...@verge.net.au>

---
v1 [Simon Horman]
- Combined patches
- Reworded changelog

v0 [Kazuya Mizuguchi]
---
 drivers/net/ethernet/renesas/ravb.h      | 10 ++++++++++
 drivers/net/ethernet/renesas/ravb_main.c | 29 +++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/drivers/net/ethernet/renesas/ravb.h 
b/drivers/net/ethernet/renesas/ravb.h
index f1109661a533..d7c91d48cc48 100644
--- a/drivers/net/ethernet/renesas/ravb.h
+++ b/drivers/net/ethernet/renesas/ravb.h
@@ -76,6 +76,7 @@ enum ravb_reg {
        CDAR20  = 0x0060,
        CDAR21  = 0x0064,
        ESR     = 0x0088,
+       APSR    = 0x008C,       /* R-Car Gen3 only */
        RCR     = 0x0090,
        RQC0    = 0x0094,
        RQC1    = 0x0098,
@@ -248,6 +249,15 @@ enum ESR_BIT {
        ESR_EIL         = 0x00001000,
 };
 
+/* APSR */
+enum APSR_BIT {
+       APSR_MEMS               = 0x00000002,
+       APSR_CMSW               = 0x00000010,
+       APSR_DM                 = 0x00006000,
+       APSR_DM_RDM             = 0x00002000,
+       APSR_DM_TDM             = 0x00004000,
+};
+
 /* RCR */
 enum RCR_BIT {
        RCR_EFFS        = 0x00000001,
diff --git a/drivers/net/ethernet/renesas/ravb_main.c 
b/drivers/net/ethernet/renesas/ravb_main.c
index 89ac1e3f6175..9fb4c04c5885 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -1904,6 +1904,29 @@ static void ravb_set_config_mode(struct net_device *ndev)
        }
 }
 
+static void ravb_set_delay_mode(struct net_device *ndev)
+{
+       struct ravb_private *priv = netdev_priv(ndev);
+
+       if (priv->chip_id != RCAR_GEN2) {
+               switch (priv->phy_interface) {
+               case PHY_INTERFACE_MODE_RGMII_ID:
+                       ravb_modify(ndev, APSR, APSR_DM, APSR_DM_RDM |
+                                  APSR_DM_TDM);
+                       break;
+               case PHY_INTERFACE_MODE_RGMII_RXID:
+                       ravb_modify(ndev, APSR, APSR_DM, APSR_DM_RDM);
+                       break;
+               case PHY_INTERFACE_MODE_RGMII_TXID:
+                       ravb_modify(ndev, APSR, APSR_DM, APSR_DM_TDM);
+                       break;
+               default:
+                       ravb_modify(ndev, APSR, APSR_DM, 0);
+                       break;
+               }
+       }
+}
+
 static int ravb_probe(struct platform_device *pdev)
 {
        struct device_node *np = pdev->dev.of_node;
@@ -2016,6 +2039,9 @@ static int ravb_probe(struct platform_device *pdev)
        /* Request GTI loading */
        ravb_modify(ndev, GCCR, GCCR_LTI, GCCR_LTI);
 
+       /* Set APSR */
+       ravb_set_delay_mode(ndev);
+
        /* Allocate descriptor base address table */
        priv->desc_bat_size = sizeof(struct ravb_desc) * DBAT_ENTRY_NUM;
        priv->desc_bat = dma_alloc_coherent(ndev->dev.parent, 
priv->desc_bat_size,
@@ -2152,6 +2178,9 @@ static int __maybe_unused ravb_resume(struct device *dev)
        /* Request GTI loading */
        ravb_modify(ndev, GCCR, GCCR_LTI, GCCR_LTI);
 
+       /* Set APSR */
+       ravb_set_delay_mode(ndev);
+
        /* Restore descriptor base address table */
        ravb_write(ndev, priv->desc_bat_dma, DBAT);
 
-- 
2.7.0.rc3.207.g0ac5344