sun8i_emac: add support for setting EMAC TX/RX delay

Some boards have the EMAC TX/RX lanes wired with a different length with
the clock lane, which can be workarounded by setting a TX/RX delay in
the EMAC.

This kind of delays are already defined in the newest device tree
binding of dwmac-sun8i, which has already entered linux-next.

Add support for setting these delays.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Reviewed-by: Jagan Teki <jagan@openedev.com>

diff --git a/drivers/net/sun8i_emac.c b/drivers/net/sun8i_emac.c
index 3ba3a1ff8be2df98f3811908e1f8f5f3416aa624..c9798445c7dd1a675f7cba2034fef3e850fff1c3 100644 (file)
--- a/drivers/net/sun8i_emac.c
+++ b/drivers/net/sun8i_emac.c
@@ -60,6 +60,10 @@
 #define SC_ETCS_MASK           GENMASK(1, 0)
 #define SC_ETCS_EXT_GMII       0x1
 #define SC_ETCS_INT_GMII       0x2
+#define SC_ETXDC_MASK          GENMASK(12, 10)
+#define SC_ETXDC_OFFSET                10
+#define SC_ERXDC_MASK          GENMASK(9, 5)
+#define SC_ERXDC_OFFSET                5
 
 #define CONFIG_MDIO_TIMEOUT    (3 * CONFIG_SYS_HZ)
 
@@ -140,6 +144,8 @@ struct emac_eth_dev {
 struct sun8i_eth_pdata {
        struct eth_pdata eth_pdata;
        u32 reset_delays[3];
+       int tx_delay_ps;
+       int rx_delay_ps;
 };
 
 
@@ -273,7 +279,8 @@ static int sun8i_emac_set_syscon_ephy(struct emac_eth_dev *priv, u32 *reg)
        return 0;
 }
 
-static int sun8i_emac_set_syscon(struct emac_eth_dev *priv)
+static int sun8i_emac_set_syscon(struct sun8i_eth_pdata *pdata,
+                                struct emac_eth_dev *priv)
 {
        int ret;
        u32 reg;
@@ -312,6 +319,14 @@ static int sun8i_emac_set_syscon(struct emac_eth_dev *priv)
                return -EINVAL;
        }
 
+       if (pdata->tx_delay_ps)
+               reg |= ((pdata->tx_delay_ps / 100) << SC_ETXDC_OFFSET)
+                        & SC_ETXDC_MASK;
+
+       if (pdata->rx_delay_ps)
+               reg |= ((pdata->rx_delay_ps / 100) << SC_ERXDC_OFFSET)
+                        & SC_ERXDC_MASK;
+
        writel(reg, priv->sysctl_reg + 0x30);
 
        return 0;
@@ -784,13 +799,14 @@ static void sun8i_emac_eth_stop(struct udevice *dev)
 
 static int sun8i_emac_eth_probe(struct udevice *dev)
 {
-       struct eth_pdata *pdata = dev_get_platdata(dev);
+       struct sun8i_eth_pdata *sun8i_pdata = dev_get_platdata(dev);
+       struct eth_pdata *pdata = &sun8i_pdata->eth_pdata;
        struct emac_eth_dev *priv = dev_get_priv(dev);
 
        priv->mac_reg = (void *)pdata->iobase;
 
        sun8i_emac_board_setup(priv);
-       sun8i_emac_set_syscon(priv);
+       sun8i_emac_set_syscon(sun8i_pdata, priv);
 
        sun8i_mdio_init(dev->name, dev);
        priv->bus = miiphy_get_dev_by_name(dev->name);
@@ -891,6 +907,18 @@ static int sun8i_emac_eth_ofdata_to_platdata(struct udevice *dev)
        if (!priv->use_internal_phy)
                parse_phy_pins(dev);
 
+       sun8i_pdata->tx_delay_ps = fdtdec_get_int(gd->fdt_blob, node,
+                                                 "allwinner,tx-delay-ps", 0);
+       if (sun8i_pdata->tx_delay_ps < 0 || sun8i_pdata->tx_delay_ps > 700)
+               printf("%s: Invalid TX delay value %d\n", __func__,
+                      sun8i_pdata->tx_delay_ps);
+
+       sun8i_pdata->rx_delay_ps = fdtdec_get_int(gd->fdt_blob, node,
+                                                 "allwinner,rx-delay-ps", 0);
+       if (sun8i_pdata->rx_delay_ps < 0 || sun8i_pdata->rx_delay_ps > 3100)
+               printf("%s: Invalid RX delay value %d\n", __func__,
+                      sun8i_pdata->rx_delay_ps);
+
 #ifdef CONFIG_DM_GPIO
        if (fdtdec_get_bool(gd->fdt_blob, dev_of_offset(dev),
                            "snps,reset-active-low"))