[PATCH RFC net-next v4 05/14] net: stmmac: provide core phylink PCS infrastructure

Russell King (Oracle)
2024-08-05T10:25:11Z

There are some common operations shared between the dwmac hwifs, the
only difference is where they are located within the device. These
are already present in the form of dwmac_rane() and dwmac_ctrl_ane().
Rather than use these (which don't quite fit with phylink PCS, provide
phylink PCS specific versions. Also provide an implementation to parse
the RSGMII status register.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
drivers/net/ethernet/stmicro/stmmac/Makefile | 2 +-
.../net/ethernet/stmicro/stmmac/stmmac_pcs.c | 47 +++++++++++++++++
.../net/ethernet/stmicro/stmmac/stmmac_pcs.h | 50 +++++++++++++++++++
3 files changed, 98 insertions(+), 1 deletion(-)
create mode 100644 drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c

diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
index c2f0e91f6bf8..9e15f7615ff4 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Makefile
+++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
@@ -6,7 +6,7 @@ stmmac-objs:= stmmac_main.o stmmac_ethtool.o stmmac_mdio.o ring_mode.o \
mmc_core.o stmmac_hwtstamp.o stmmac_ptp.o dwmac4_descs.o \
dwmac4_dma.o dwmac4_lib.o dwmac4_core.o dwmac5.o hwif.o \
stmmac_tc.o dwxgmac2_core.o dwxgmac2_dma.o dwxgmac2_descs.o \
- stmmac_xdp.o stmmac_est.o \
+ stmmac_xdp.o stmmac_est.o stmmac_pcs.o \
$(stmmac-y)

stmmac-$(CONFIG_STMMAC_SELFTESTS) += stmmac_selftests.o
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
new file mode 100644
index 000000000000..292c039c9778
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include "stmmac.h"
+#include "stmmac_pcs.h"
+
+static void __dwmac_ctrl_ane(struct stmmac_pcs *spcs, bool ane, bool srgmi_ral,
+ bool loopback)
+
+{
+ u32 val;
+
+ val = readl(spcs->pcs_base + GMAC_AN_CTRL(0));
+
+ /* Enable and restart the Auto-Negotiation */
+ if (ane)
+ val |= GMAC_AN_CTRL_ANE | GMAC_AN_CTRL_RAN;
+ else
+ val &= ~GMAC_AN_CTRL_ANE;
+
+ /* In case of MAC-2-MAC connection, block is configured to operate
+ * according to MAC conf register.
+ */
+ if (srgmi_ral)
+ val |= GMAC_AN_CTRL_SGMRAL;
+
+ if (loopback)
+ val |= GMAC_AN_CTRL_ELE;
+ else
+ val &= ~GMAC_AN_CTRL_ELE;
+
+ writel(val, spcs->pcs_base + GMAC_AN_CTRL(0));
+}
+
+int dwmac_pcs_config(struct phylink_pcs *pcs, unsigned int neg_mode,
+ phy_interface_t interface,
+ const unsigned long *advertising,
+ bool permit_pause_to_mac)
+{
+ struct stmmac_pcs *spcs = phylink_pcs_to_stmmac_pcs(pcs);
+
+ /* The RGMII interface does not have the GMAC_AN_CTRL register */
+ if (phy_interface_mode_is_rgmii(spcs->priv->plat->mac_interface))
+ return 0;
+
+ __dwmac_ctrl_ane(spcs, true, spcs->priv->hw->ps, false);
+
+ return 0;
+}
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
index 4a684c97dfae..f0d6442711ff 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
@@ -46,6 +46,19 @@
#define GMAC_ANE_RFE_SHIFT 12
#define GMAC_ANE_ACK BIT(14)

+/* MAC specific status - for RGMII and SGMII. These appear as
+ * GMAC_RGSMIIIS[15:0] and GMAC_PHYIF_CONTROL_STATUS[31:16]
+ */
+#define GMAC_RS_STAT_LNKMOD BIT(0)
+#define GMAC_RS_STAT_SPEED GENMASK(2, 1)
+#define GMAC_RS_STAT_LNKSTS BIT(3)
+#define GMAC_RS_STAT_JABTO BIT(4)
+#define GMAC_RS_STAT_FALSECARDET BIT(5)
+
+#define GMAC_RS_STAT_SPEED_125 2
+#define GMAC_RS_STAT_SPEED_25 1
+#define GMAC_RS_STAT_SPEED_2_5 0
+
/**
* dwmac_pcs_isr - TBI, RTBI, or SGMII PHY ISR
* @ioaddr: IO registers pointer
@@ -109,4 +122,41 @@ static inline void dwmac_ctrl_ane(void __iomem *ioaddr, u32 reg, bool ane,

writel(value, ioaddr + GMAC_AN_CTRL(reg));
}
+
+static inline bool dwmac_rs_decode_stat(struct phylink_link_state *state,
+ uint16_t rs_stat)
+{
+ unsigned int speed;
+
+ state->link = !!(rs_stat & GMAC_RS_STAT_LNKSTS);
+ if (!state->link)
+ return false;
+
+ speed = FIELD_GET(GMAC_RS_STAT_SPEED, rs_stat);
+ switch (speed) {
+ case GMAC_RS_STAT_SPEED_125:
+ state->speed = SPEED_1000;
+ break;
+ case GMAC_RS_STAT_SPEED_25:
+ state->speed = SPEED_100;
+ break;
+ case GMAC_RS_STAT_SPEED_2_5:
+ state->speed = SPEED_10;
+ break;
+ default:
+ state->link = false;
+ return false;
+ }
+
+ state->duplex = rs_stat & GMAC_RS_STAT_LNKMOD ?
+ DUPLEX_FULL : DUPLEX_HALF;
+
+ return true;
+}
+
+int dwmac_pcs_config(struct phylink_pcs *pcs, unsigned int neg_mode,
+ phy_interface_t interface,
+ const unsigned long *advertising,
+ bool permit_pause_to_mac);
+
#endif /* __STMMAC_PCS_H__ */
--
2.30.2