[PATCH 0/2] net-next: stmmac: dwmac-mediatek: add more support for RMII

[PATCH 0/2] net-next: stmmac: dwmac-mediatek: add more support for RMII

[Biao Huang]

This series is for support RMII when MT2712 SoC provides the reference clock.

Biao Huang (2):
  net-next: stmmac: mediatek: add more suuport for RMII
  net-next: dt-binding: dwmac-mediatek: add more description for RMII

 .../bindings/net/mediatek-dwmac.txt           | 17 +++-
 .../ethernet/stmicro/stmmac/dwmac-mediatek.c  | 85 +++++++++++++------
 2 files changed, 74 insertions(+), 28 deletions(-)

--
2.24.0

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

[Biao Huang]

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@mediatek.com>
---
 .../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

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

[Andrew Lunn]

On Thu, Dec 12, 2019 at 10:41:44AM +0800, Biao Huang wrote:
> 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.

Hi Biao

Subject line has a typo.

> @@ -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);
> +		}
> +	}

Please don't use a binary property. This is a clock, so describe it in
DT as a clock. Add it to the existing list of clocks.

   Andrew

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

[Andrew Lunn]

> The clock labeled as "rmii_internal" is needed only in RMII(when MAC provides
> reference clock), and useless for RGMII/MII/RMII(when phy provides reference
> clock).
> 
> So, add a boolean flag to indicate where the RMII reference clock is from, MAC
> or PHY, if MAC, enable the "rmii_internal", or disable it.
> and this clock already documented in dt-binding in PATCH 2/2.
> 
> For power saving, it should not be enabled in default, so can't add it to the
> existing list of clocks directly.
> 
> Any advice for this special case?

O.K. Add the boolean, but also add the clock to the list of clocks in
DT. Don't hard code the clock name in the driver.

    Andrew

[PATCH 2/2] net-next: dt-binding: dwmac-mediatek: add more description for RMII

[Biao Huang]

MT2712 SoC can provides RMII reference clock,
so add corresponding description in dt-binding.

Signed-off-by: Biao Huang <biao.huang@mediatek.com>
---
 .../devicetree/bindings/net/mediatek-dwmac.txt  | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/mediatek-dwmac.txt b/Documentation/devicetree/bindings/net/mediatek-dwmac.txt
index 8a08621a5b54..34f692ea0406 100644
--- a/Documentation/devicetree/bindings/net/mediatek-dwmac.txt
+++ b/Documentation/devicetree/bindings/net/mediatek-dwmac.txt
@@ -14,7 +14,9 @@ Required properties:
 	Should be "macirq" for the main MAC IRQ
 - clocks: Must contain a phandle for each entry in clock-names.
 - clock-names: The name of the clock listed in the clocks property. These are
-	"axi", "apb", "mac_main", "ptp_ref" for MT2712 SoC
+	"axi", "apb", "mac_main", "ptp_ref" for MT2712 SoC.
+	"rmii_internal" is optional, only for RMII when the reference clock is
+	from MT2712 SoC.
 - mac-address: See ethernet.txt in the same directory
 - phy-mode: See ethernet.txt in the same directory
 - mediatek,pericfg: A phandle to the syscon node that control ethernet
@@ -23,8 +25,10 @@ Required properties:
 Optional properties:
 - mediatek,tx-delay-ps: TX clock delay macro value. Default is 0.
 	It should be defined for RGMII/MII interface.
+	It should be defined for RMII interface when the reference clock is from MT2712 SoC.
 - mediatek,rx-delay-ps: RX clock delay macro value. Default is 0.
-	It should be defined for RGMII/MII/RMII interface.
+	It should be defined for RGMII/MII interface.
+	It should be defined for RMII interface.
 Both delay properties need to be a multiple of 170 for RGMII interface,
 or will round down. Range 0~31*170.
 Both delay properties need to be a multiple of 550 for MII/RMII interface,
@@ -34,13 +38,20 @@ or will round down. Range 0~31*550.
 	reference clock, which is from external PHYs, is connected to RXC pin
 	on MT2712 SoC.
 	Otherwise, is connected to TXC pin.
+- mediatek,rmii-clk-from-mac: boolean property, if present indicates that
+	MT2712 SoC provides the RMII reference clock, which outputs to TXC pin only.
 - mediatek,txc-inverse: boolean property, if present indicates that
 	1. tx clock will be inversed in MII/RGMII case,
 	2. tx clock inside MAC will be inversed relative to reference clock
 	   which is from external PHYs in RMII case, and it rarely happen.
+	3. the reference clock, which outputs to TXC pin will be inversed in RMII case
+	   when the reference clock is from MT2712 SoC.
 - mediatek,rxc-inverse: boolean property, if present indicates that
 	1. rx clock will be inversed in MII/RGMII case.
-	2. reference clock will be inversed when arrived at MAC in RMII case.
+	2. reference clock will be inversed when arrived at MAC in RMII case, when
+	   the reference clock is from external PHYs.
+	3. the inside clock, which be sent to MAC, will be inversed in RMII case when
+	   the reference clock is from MT2712 SoC.
 - assigned-clocks: mac_main and ptp_ref clocks
 - assigned-clock-parents: parent clocks of the assigned clocks
 
-- 
2.18.0