net: stmmac: dwmac-sun8i: Support different ranges for TX/RX delay chains

On the R40 SoC, the RX delay chain only has a range of 0~7 (hundred
picoseconds), instead of 0~31. Also the TX delay chain is completely
absent.

This patch adds support for different ranges by adding per-compatible
maximum values in the variant data. A maximum of 0 indicates that the
delay chain is not supported or absent.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
index 79e104a..4f5612a 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c
@@ -47,6 +47,12 @@
  * @support_mii:               Does the MAC handle MII
  * @support_rmii:              Does the MAC handle RMII
  * @support_rgmii:             Does the MAC handle RGMII
+ *
+ * @rx_delay_max:              Maximum raw value for RX delay chain
+ * @tx_delay_max:              Maximum raw value for TX delay chain
+ *                             These two also indicate the bitmask for
+ *                             the RX and TX delay chain registers. A
+ *                             value of zero indicates this is not supported.
  */
 struct emac_variant {
        u32 default_syscon_value;
@@ -55,6 +61,8 @@ struct emac_variant {
        bool support_mii;
        bool support_rmii;
        bool support_rgmii;
+       u8 rx_delay_max;
+       u8 tx_delay_max;
 };
 
 /* struct sunxi_priv_data - hold all sunxi private data
@@ -91,7 +99,9 @@ static const struct emac_variant emac_variant_h3 = {
        .soc_has_internal_phy = true,
        .support_mii = true,
        .support_rmii = true,
-       .support_rgmii = true
+       .support_rgmii = true,
+       .rx_delay_max = 31,
+       .tx_delay_max = 7,
 };
 
 static const struct emac_variant emac_variant_v3s = {
@@ -106,7 +116,9 @@ static const struct emac_variant emac_variant_a83t = {
        .syscon_field = &sun8i_syscon_reg_field,
        .soc_has_internal_phy = false,
        .support_mii = true,
-       .support_rgmii = true
+       .support_rgmii = true,
+       .rx_delay_max = 31,
+       .tx_delay_max = 7,
 };
 
 static const struct emac_variant emac_variant_a64 = {
@@ -115,7 +127,9 @@ static const struct emac_variant emac_variant_a64 = {
        .soc_has_internal_phy = false,
        .support_mii = true,
        .support_rmii = true,
-       .support_rgmii = true
+       .support_rgmii = true,
+       .rx_delay_max = 31,
+       .tx_delay_max = 7,
 };
 
 #define EMAC_BASIC_CTL0 0x00
@@ -219,9 +233,7 @@ static const struct emac_variant emac_variant_a64 = {
 #define SYSCON_RMII_EN         BIT(13) /* 1: enable RMII (overrides EPIT) */
 
 /* Generic system control EMAC_CLK bits */
-#define SYSCON_ETXDC_MASK              GENMASK(2, 0)
 #define SYSCON_ETXDC_SHIFT             10
-#define SYSCON_ERXDC_MASK              GENMASK(4, 0)
 #define SYSCON_ERXDC_SHIFT             5
 /* EMAC PHY Interface Type */
 #define SYSCON_EPIT                    BIT(2) /* 1: RGMII, 0: MII */
@@ -847,8 +859,9 @@ static int sun8i_dwmac_set_syscon(struct stmmac_priv *priv)
                }
                val /= 100;
                dev_dbg(priv->device, "set tx-delay to %x\n", val);
-               if (val <= SYSCON_ETXDC_MASK) {
-                       reg &= ~(SYSCON_ETXDC_MASK << SYSCON_ETXDC_SHIFT);
+               if (val <= gmac->variant->tx_delay_max) {
+                       reg &= ~(gmac->variant->tx_delay_max <<
+                                SYSCON_ETXDC_SHIFT);
                        reg |= (val << SYSCON_ETXDC_SHIFT);
                } else {
                        dev_err(priv->device, "Invalid TX clock delay: %d\n",
@@ -864,8 +877,9 @@ static int sun8i_dwmac_set_syscon(struct stmmac_priv *priv)
                }
                val /= 100;
                dev_dbg(priv->device, "set rx-delay to %x\n", val);
-               if (val <= SYSCON_ERXDC_MASK) {
-                       reg &= ~(SYSCON_ERXDC_MASK << SYSCON_ERXDC_SHIFT);
+               if (val <= gmac->variant->rx_delay_max) {
+                       reg &= ~(gmac->variant->rx_delay_max <<
+                                SYSCON_ERXDC_SHIFT);
                        reg |= (val << SYSCON_ERXDC_SHIFT);
                } else {
                        dev_err(priv->device, "Invalid RX clock delay: %d\n",