[PATCH 1/2] net-next: stmmac: mediatek: add more suuport for RMII

From: Biao Huang
Date: Wed Dec 11 2019 - 21:42:22 EST


MT2712 SoC can provide the rmii reference clock, and the clock
will output from TXC pin only, which means ref_clk pin of external
PHY should connect to TXC pin in this case.
Add corresponding clock and timing settings.

Signed-off-by: Biao Huang <biao.huang@xxxxxxxxxxxx>
---
.../ethernet/stmicro/stmmac/dwmac-mediatek.c | 85 +++++++++++++------
1 file changed, 60 insertions(+), 25 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c
index bdb80421acac..af24954c7654 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c
@@ -51,10 +51,12 @@ struct mediatek_dwmac_plat_data {
const struct mediatek_dwmac_variant *variant;
struct mac_delay_struct mac_delay;
struct clk_bulk_data *clks;
+ struct clk *mac_rmii_clk;
struct device_node *np;
struct regmap *peri_regmap;
struct device *dev;
phy_interface_t phy_mode;
+ bool rmii_clk_from_mac;
bool rmii_rxc;
};

@@ -78,6 +80,7 @@ static const char * const mt2712_dwmac_clk_l[] = {

static int mt2712_set_interface(struct mediatek_dwmac_plat_data *plat)
{
+ int rmii_clk_from_mac = plat->rmii_clk_from_mac ? RMII_CLK_SRC_INTERNAL : 0;
int rmii_rxc = plat->rmii_rxc ? RMII_CLK_SRC_RXC : 0;
u32 intf_val = 0;

@@ -87,7 +90,7 @@ static int mt2712_set_interface(struct mediatek_dwmac_plat_data *plat)
intf_val |= PHY_INTF_MII;
break;
case PHY_INTERFACE_MODE_RMII:
- intf_val |= (PHY_INTF_RMII | rmii_rxc);
+ intf_val |= (PHY_INTF_RMII | rmii_rxc | rmii_clk_from_mac);
break;
case PHY_INTERFACE_MODE_RGMII:
case PHY_INTERFACE_MODE_RGMII_TXID:
@@ -173,35 +176,50 @@ static int mt2712_set_delay(struct mediatek_dwmac_plat_data *plat)
delay_val |= FIELD_PREP(ETH_DLY_RXC_INV, mac_delay->rx_inv);
break;
case PHY_INTERFACE_MODE_RMII:
- /* the rmii reference clock is from external phy,
- * and the property "rmii_rxc" indicates which pin(TXC/RXC)
- * the reference clk is connected to. The reference clock is a
- * received signal, so rx_delay/rx_inv are used to indicate
- * the reference clock timing adjustment
- */
- if (plat->rmii_rxc) {
- /* the rmii reference clock from outside is connected
- * to RXC pin, the reference clock will be adjusted
- * by RXC delay macro circuit.
- */
- delay_val |= FIELD_PREP(ETH_DLY_RXC_ENABLE, !!mac_delay->rx_delay);
- delay_val |= FIELD_PREP(ETH_DLY_RXC_STAGES, mac_delay->rx_delay);
- delay_val |= FIELD_PREP(ETH_DLY_RXC_INV, mac_delay->rx_inv);
- } else {
- /* the rmii reference clock from outside is connected
- * to TXC pin, the reference clock will be adjusted
- * by TXC delay macro circuit.
+ if (plat->rmii_clk_from_mac) {
+ /* case 1: mac provides the rmii reference clock,
+ * and the clock output to TXC pin.
+ * The egress timing can be adjusted by GTXC delay macro circuit.
+ * The ingress timing can be adjusted by TXC delay macro circuit.
*/
delay_val |= FIELD_PREP(ETH_DLY_TXC_ENABLE, !!mac_delay->rx_delay);
delay_val |= FIELD_PREP(ETH_DLY_TXC_STAGES, mac_delay->rx_delay);
delay_val |= FIELD_PREP(ETH_DLY_TXC_INV, mac_delay->rx_inv);
+
+ delay_val |= FIELD_PREP(ETH_DLY_GTXC_ENABLE, !!mac_delay->tx_delay);
+ delay_val |= FIELD_PREP(ETH_DLY_GTXC_STAGES, mac_delay->tx_delay);
+ delay_val |= FIELD_PREP(ETH_DLY_GTXC_INV, mac_delay->tx_inv);
+ } else {
+ /* case 2: the rmii reference clock is from external phy,
+ * and the property "rmii_rxc" indicates which pin(TXC/RXC)
+ * the reference clk is connected to. The reference clock is a
+ * received signal, so rx_delay/rx_inv are used to indicate
+ * the reference clock timing adjustment
+ */
+ if (plat->rmii_rxc) {
+ /* the rmii reference clock from outside is connected
+ * to RXC pin, the reference clock will be adjusted
+ * by RXC delay macro circuit.
+ */
+ delay_val |= FIELD_PREP(ETH_DLY_RXC_ENABLE, !!mac_delay->rx_delay);
+ delay_val |= FIELD_PREP(ETH_DLY_RXC_STAGES, mac_delay->rx_delay);
+ delay_val |= FIELD_PREP(ETH_DLY_RXC_INV, mac_delay->rx_inv);
+ } else {
+ /* the rmii reference clock from outside is connected
+ * to TXC pin, the reference clock will be adjusted
+ * by TXC delay macro circuit.
+ */
+ delay_val |= FIELD_PREP(ETH_DLY_TXC_ENABLE, !!mac_delay->rx_delay);
+ delay_val |= FIELD_PREP(ETH_DLY_TXC_STAGES, mac_delay->rx_delay);
+ delay_val |= FIELD_PREP(ETH_DLY_TXC_INV, mac_delay->rx_inv);
+ }
+ /* tx_inv will inverse the tx clock inside mac relateive to
+ * reference clock from external phy,
+ * and this bit is located in the same register with fine-tune
+ */
+ if (mac_delay->tx_inv)
+ fine_val = ETH_RMII_DLY_TX_INV;
}
- /* tx_inv will inverse the tx clock inside mac relateive to
- * reference clock from external phy,
- * and this bit is located in the same register with fine-tune
- */
- if (mac_delay->tx_inv)
- fine_val = ETH_RMII_DLY_TX_INV;
break;
case PHY_INTERFACE_MODE_RGMII:
case PHY_INTERFACE_MODE_RGMII_TXID:
@@ -278,6 +296,7 @@ static int mediatek_dwmac_config_dt(struct mediatek_dwmac_plat_data *plat)
mac_delay->tx_inv = of_property_read_bool(plat->np, "mediatek,txc-inverse");
mac_delay->rx_inv = of_property_read_bool(plat->np, "mediatek,rxc-inverse");
plat->rmii_rxc = of_property_read_bool(plat->np, "mediatek,rmii-rxc");
+ plat->rmii_clk_from_mac = of_property_read_bool(plat->np, "mediatek,rmii-clk-from-mac");

return 0;
}
@@ -287,6 +306,16 @@ static int mediatek_dwmac_clk_init(struct mediatek_dwmac_plat_data *plat)
const struct mediatek_dwmac_variant *variant = plat->variant;
int i, num = variant->num_clks;

+ plat->mac_rmii_clk = NULL;
+ if (plat->phy_mode == PHY_INTERFACE_MODE_RMII &&
+ plat->rmii_clk_from_mac) {
+ plat->mac_rmii_clk = devm_clk_get(plat->dev, "rmii_internal");
+ if (IS_ERR(plat->mac_rmii_clk)) {
+ dev_err(plat->dev, "Failed to get reference clk from MAC\n");
+ return PTR_ERR(plat->mac_rmii_clk);
+ }
+ }
+
plat->clks = devm_kcalloc(plat->dev, num, sizeof(*plat->clks), GFP_KERNEL);
if (!plat->clks)
return -ENOMEM;
@@ -327,6 +356,9 @@ static int mediatek_dwmac_init(struct platform_device *pdev, void *priv)
return ret;
}

+ if (plat->mac_rmii_clk)
+ clk_prepare_enable(plat->mac_rmii_clk);
+
pm_runtime_enable(&pdev->dev);
pm_runtime_get_sync(&pdev->dev);

@@ -338,6 +370,9 @@ static void mediatek_dwmac_exit(struct platform_device *pdev, void *priv)
struct mediatek_dwmac_plat_data *plat = priv;
const struct mediatek_dwmac_variant *variant = plat->variant;

+ if (plat->mac_rmii_clk)
+ clk_disable_unprepare(plat->mac_rmii_clk);
+
clk_bulk_disable_unprepare(variant->num_clks, plat->clks);

pm_runtime_put_sync(&pdev->dev);
--
2.18.0