[PATCH net-next 8/8] net: stmmac: qcom-ethqos: add a DMA-reset quirk for sa8775p-ride-r3

[Bartosz Golaszewski <brgl@bgdev.pl>]

From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

On sa8775p-ride the RX clocks from the AQR115C PHY are not available at
the time of the DMA reset so we need to loop TX clocks to RX and then
disable loopback after link-up. Use the provided callbacks to do it for
this board.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 .../stmicro/stmmac/dwmac-qcom-ethqos.c        | 33 +++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
index dac91bc72070..ec43449d0252 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
@@ -21,6 +21,7 @@
 #define RGMII_IO_MACRO_CONFIG2		0x1C
 #define RGMII_IO_MACRO_DEBUG1		0x20
 #define EMAC_SYSTEM_LOW_POWER_DEBUG	0x28
+#define EMAC_WRAPPER_SGMII_PHY_CNTRL1	0xf4
 
 /* RGMII_IO_MACRO_CONFIG fields */
 #define RGMII_CONFIG_FUNC_CLK_EN		BIT(30)
@@ -79,6 +80,9 @@
 #define ETHQOS_MAC_CTRL_SPEED_MODE		BIT(14)
 #define ETHQOS_MAC_CTRL_PORT_SEL		BIT(15)
 
+/* EMAC_WRAPPER_SGMII_PHY_CNTRL1 bits */
+#define SGMII_PHY_CNTRL1_SGMII_TX_TO_RX_LOOPBACK_EN	BIT(3)
+
 #define SGMII_10M_RX_CLK_DVDR			0x31
 
 struct ethqos_emac_por {
@@ -678,6 +682,29 @@ static int ethqos_configure(struct qcom_ethqos *ethqos)
 	return ethqos->configure_func(ethqos);
 }
 
+static void qcom_ethqos_set_serdes_loopback(struct qcom_ethqos *ethqos,
+					    bool enable)
+{
+	rgmii_updatel(ethqos,
+		      SGMII_PHY_CNTRL1_SGMII_TX_TO_RX_LOOPBACK_EN,
+		      enable ? SGMII_PHY_CNTRL1_SGMII_TX_TO_RX_LOOPBACK_EN : 0,
+		      EMAC_WRAPPER_SGMII_PHY_CNTRL1);
+}
+
+static void qcom_ethqos_open(struct net_device *pdev, void *priv)
+{
+	struct qcom_ethqos *ethqos = priv;
+
+	qcom_ethqos_set_serdes_loopback(ethqos, true);
+}
+
+static void qcom_ethqos_link_up(struct net_device *ndev, void *priv)
+{
+	struct qcom_ethqos *ethqos = priv;
+
+	qcom_ethqos_set_serdes_loopback(ethqos, false);
+}
+
 static void ethqos_fix_mac_speed(void *priv, unsigned int speed, unsigned int mode)
 {
 	struct qcom_ethqos *ethqos = priv;
@@ -861,6 +888,12 @@ static int qcom_ethqos_probe(struct platform_device *pdev)
 	if (data->dma_addr_width)
 		plat_dat->host_dma_width = data->dma_addr_width;
 
+	if (of_device_is_compatible(np, "qcom,sa8775p-ethqos") &&
+	    ethqos->phy_mode == PHY_INTERFACE_MODE_OCSGMII) {
+		plat_dat->open = qcom_ethqos_open;
+		plat_dat->link_up = qcom_ethqos_link_up;
+	}
+
 	if (ethqos->serdes_phy) {
 		plat_dat->serdes_powerup = qcom_ethqos_serdes_powerup;
 		plat_dat->serdes_powerdown  = qcom_ethqos_serdes_powerdown;
-- 
2.43.0