[v2, PATCH 1/2] net-next: stmmac: mediatek: add more support for RMII

From: Biao Huang
Date: Mon Dec 16 2019 - 00:40:25 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 | 89 +++++++++++++------
1 file changed, 60 insertions(+), 29 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c
index bdb80421acac..9e4b83832938 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-mediatek.c
@@ -55,6 +55,8 @@ struct mediatek_dwmac_plat_data {
struct regmap *peri_regmap;
struct device *dev;
phy_interface_t phy_mode;
+ int num_clks_to_config;
+ bool rmii_clk_from_mac;
bool rmii_rxc;
};

@@ -73,21 +75,33 @@ struct mediatek_dwmac_variant {

/* list of clocks required for mac */
static const char * const mt2712_dwmac_clk_l[] = {
- "axi", "apb", "mac_main", "ptp_ref"
+ "axi", "apb", "mac_main", "ptp_ref", "rmii_internal"
};

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;

+ /* The clock labeled as "rmii_internal" in mt2712_dwmac_clk_l is needed
+ * only in RMII(when MAC provides the reference clock), and useless for
+ * RGMII/MII/RMII(when PHY provides the reference clock).
+ * num_clks_to_config indicates the real number of clocks should be
+ * configured, equals to (plat->variant->num_clks - 1) in default for all the case,
+ * then +1 for rmii_clk_from_mac case.
+ */
+ plat->num_clks_to_config = plat->variant->num_clks - 1;
+
/* select phy interface in top control domain */
switch (plat->phy_mode) {
case PHY_INTERFACE_MODE_MII:
intf_val |= PHY_INTF_MII;
break;
case PHY_INTERFACE_MODE_RMII:
- intf_val |= (PHY_INTF_RMII | rmii_rxc);
+ if (plat->rmii_clk_from_mac)
+ plat->num_clks_to_config++;
+ 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 +187,50 @@ 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 +307,7 @@ 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;
}
@@ -294,6 +324,8 @@ static int mediatek_dwmac_clk_init(struct mediatek_dwmac_plat_data *plat)
for (i = 0; i < num; i++)
plat->clks[i].id = variant->clk_list[i];

+ plat->num_clks_to_config = variant->num_clks;
+
return devm_clk_bulk_get(plat->dev, num, plat->clks);
}

@@ -321,7 +353,7 @@ static int mediatek_dwmac_init(struct platform_device *pdev, void *priv)
return ret;
}

- ret = clk_bulk_prepare_enable(variant->num_clks, plat->clks);
+ ret = clk_bulk_prepare_enable(plat->num_clks_to_config, plat->clks);
if (ret) {
dev_err(plat->dev, "failed to enable clks, err = %d\n", ret);
return ret;
@@ -336,9 +368,8 @@ static int mediatek_dwmac_init(struct platform_device *pdev, void *priv)
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;

- clk_bulk_disable_unprepare(variant->num_clks, plat->clks);
+ clk_bulk_disable_unprepare(plat->num_clks_to_config, plat->clks);

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