[PATCH V1 5/5] net: fec: add MAC internal delayed clock feature support

From: Joakim Zhang
Date: Fri Jul 09 2021 - 03:54:20 EST


From: Fugang Duan <fugang.duan@xxxxxxx>

i.MX8QM ENET IP version support timing specification that MAC
integrate clock delay in RGMII mode, the delayed TXC/RXC as an
alternative option to work well with various PHYs.

Signed-off-by: Fugang Duan <fugang.duan@xxxxxxx>
Signed-off-by: Joakim Zhang <qiangqing.zhang@xxxxxxx>
---
drivers/net/ethernet/freescale/fec.h | 6 ++++++
drivers/net/ethernet/freescale/fec_main.c | 26 +++++++++++++++++++++++
2 files changed, 32 insertions(+)

diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
index 0a741bc440e4..ae3259164395 100644
--- a/drivers/net/ethernet/freescale/fec.h
+++ b/drivers/net/ethernet/freescale/fec.h
@@ -381,6 +381,9 @@ struct bufdesc_ex {
#define FEC_DEFAULT_IMASK (FEC_ENET_TXF | FEC_ENET_RXF)
#define FEC_RX_DISABLED_IMASK (FEC_DEFAULT_IMASK & (~FEC_ENET_RXF))

+#define FEC_ENET_TXC_DLY ((uint)0x00010000)
+#define FEC_ENET_RXC_DLY ((uint)0x00020000)
+
/* ENET interrupt coalescing macro define */
#define FEC_ITR_CLK_SEL (0x1 << 30)
#define FEC_ITR_EN (0x1 << 31)
@@ -543,6 +546,7 @@ struct fec_enet_private {
struct clk *clk_ref;
struct clk *clk_enet_out;
struct clk *clk_ptp;
+ struct clk *clk_2x_txclk;

bool ptp_clk_on;
struct mutex ptp_clk_mutex;
@@ -565,6 +569,8 @@ struct fec_enet_private {
uint phy_speed;
phy_interface_t phy_interface;
struct device_node *phy_node;
+ bool rgmii_txc_dly;
+ bool rgmii_rxc_dly;
int link;
int full_duplex;
int speed;
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 24082b3f2118..18ab60322688 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1137,6 +1137,13 @@ fec_restart(struct net_device *ndev)
if (fep->bufdesc_ex)
ecntl |= (1 << 4);

+ if (fep->quirks & FEC_QUIRK_DELAYED_CLKS_SUPPORT &&
+ fep->rgmii_txc_dly)
+ ecntl |= FEC_ENET_TXC_DLY;
+ if (fep->quirks & FEC_QUIRK_DELAYED_CLKS_SUPPORT &&
+ fep->rgmii_rxc_dly)
+ ecntl |= FEC_ENET_RXC_DLY;
+
#ifndef CONFIG_M5272
/* Enable the MIB statistic event counters */
writel(0 << 31, fep->hwp + FEC_MIB_CTRLSTAT);
@@ -2000,6 +2007,10 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable)
if (ret)
goto failed_clk_ref;

+ ret = clk_prepare_enable(fep->clk_2x_txclk);
+ if (ret)
+ goto failed_clk_2x_txclk;
+
fec_enet_phy_reset_after_clk_enable(ndev);
} else {
clk_disable_unprepare(fep->clk_enet_out);
@@ -2010,10 +2021,14 @@ static int fec_enet_clk_enable(struct net_device *ndev, bool enable)
mutex_unlock(&fep->ptp_clk_mutex);
}
clk_disable_unprepare(fep->clk_ref);
+ clk_disable_unprepare(fep->clk_2x_txclk);
}

return 0;

+failed_clk_2x_txclk:
+ if (fep->clk_ref)
+ clk_disable_unprepare(fep->clk_ref);
failed_clk_ref:
if (fep->clk_ptp) {
mutex_lock(&fep->ptp_clk_mutex);
@@ -3761,6 +3776,12 @@ fec_probe(struct platform_device *pdev)
if (ret)
goto failed_stop_mode;

+ if (of_get_property(np, "fsl,rgmii_txc_dly", NULL))
+ fep->rgmii_txc_dly = true;
+
+ if (of_get_property(np, "fsl,rgmii_rxc_dly", NULL))
+ fep->rgmii_rxc_dly = true;
+
phy_node = of_parse_phandle(np, "phy-handle", 0);
if (!phy_node && of_phy_is_fixed_link(np)) {
ret = of_phy_register_fixed_link(np);
@@ -3812,6 +3833,11 @@ fec_probe(struct platform_device *pdev)
fep->clk_ref = NULL;
fep->clk_ref_rate = clk_get_rate(fep->clk_ref);

+ /* clk_2x_txclk is optional, depends on board */
+ fep->clk_2x_txclk = devm_clk_get(&pdev->dev, "enet_2x_txclk");
+ if (IS_ERR(fep->clk_2x_txclk))
+ fep->clk_2x_txclk = NULL;
+
fep->bufdesc_ex = fep->quirks & FEC_QUIRK_HAS_BUFDESC_EX;
fep->clk_ptp = devm_clk_get(&pdev->dev, "ptp");
if (IS_ERR(fep->clk_ptp)) {
--
2.17.1