[PATCH RFC net-next v2 11/17] net: stmmac: Introduce internal PCS config register getter

[Serge Semin <fancer.lancer@gmail.com>]

The optional PCS module CSRs are mainly represented in the framework of
the address spaces [0x00c0:0x00db] on DW GMAC and [0x00e0:0x00f7] on DW
QoS Eth. The spaces mapping is identical in both IP-cores. But the link
state retrieved from the PHY or from another MAC (in MAC2MAC
setup) is mapped over the SGMII/RGMII/SMII Control and Status register in
a non-compatible way. In particular the DW GMAC register have the link
state mapped at the [15:0] field, and the DW QoS Eth register have it
mapped at the [31:16] field. Other than that the fields semantics is
identical - it's the TX_CONFIG_REG[15:0] register (see SGMII specification
for details) with a bit re-ordered fields and extended with some
SMII-specific flags:
tx_config_reg[0]:   LNKMOD
tx_config_reg[1:2]: LNKSPEED
tx_config_reg[3]:   LNKSTS
tx_config_reg[4]:   JABTO (Jabber Timeout, SMII-specific)
tx_config_reg[5]:   FALSCARDET (False Carrier Detected, SMII-specific)

In order to provide a fully generic internal STMMAC PCS module, let's
introduce the MAC-specific callback returning the link state detected by
the internal PCS.

Note the callback name has been chosen to be referring to the
TX_CONFIG_REG data described in the IP-core databooks and in the SGMII
specification.

Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac1000.h     |  1 +
 .../net/ethernet/stmicro/stmmac/dwmac1000_core.c    | 11 +++++++++++
 drivers/net/ethernet/stmicro/stmmac/dwmac4.h        |  1 +
 drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c   | 13 +++++++++++++
 drivers/net/ethernet/stmicro/stmmac/hwif.h          |  3 +++
 5 files changed, 29 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h b/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
index 4296ddda8aaa..f3a95d27298c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
@@ -86,6 +86,7 @@ enum power_event {
 #define GMAC_RGSMIIIS		0x000000d8	/* RGMII/SMII status */
 
 /* SGMII/RGMII status register */
+#define GMAC_RGSMIIIS_CONFIG_REG	GENMASK(15, 0)
 #define GMAC_RGSMIIIS_LNKMODE		BIT(0)
 #define GMAC_RGSMIIIS_SPEED		GENMASK(2, 1)
 #define GMAC_RGSMIIIS_SPEED_SHIFT	1
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
index e525b92955b4..1e50cc573407 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
@@ -365,6 +365,16 @@ static void dwmac1000_set_eee_timer(struct mac_device_info *hw, int ls, int tw)
 	writel(value, ioaddr + LPI_TIMER_CTRL);
 }
 
+static u16 dwmac1000_pcs_get_config_reg(struct mac_device_info *hw)
+{
+	void __iomem *ioaddr = hw->pcsr;
+	u32 val;
+
+	val = readl(ioaddr + GMAC_RGSMIIIS);
+
+	return FIELD_GET(GMAC_RGSMIIIS_CONFIG_REG, val);
+}
+
 static void dwmac1000_ctrl_ane(void __iomem *pcsaddr, bool ane, bool srgmi_ral,
 			       bool loopback)
 {
@@ -568,6 +578,7 @@ const struct stmmac_ops dwmac1000_ops = {
 	.set_eee_timer = dwmac1000_set_eee_timer,
 	.set_eee_pls = dwmac1000_set_eee_pls,
 	.debug = dwmac1000_debug,
+	.pcs_get_config_reg = dwmac1000_pcs_get_config_reg,
 	.pcs_ctrl_ane = dwmac1000_ctrl_ane,
 	.set_mac_loopback = dwmac1000_set_mac_loopback,
 };
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
index d3c5306f1c41..bb2997191f08 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
@@ -567,6 +567,7 @@ static inline u32 mtl_low_credx_base_addr(const struct dwmac4_addrs *addrs,
 #define GMAC_PHYIF_CTRLSTATUS_TC		BIT(0)
 #define GMAC_PHYIF_CTRLSTATUS_LUD		BIT(1)
 #define GMAC_PHYIF_CTRLSTATUS_SMIDRXS		BIT(4)
+#define GMAC_PHYIF_CTRLSTATUS_CONFIG_REG	GENMASK(31, 16)
 #define GMAC_PHYIF_CTRLSTATUS_LNKMOD		BIT(16)
 #define GMAC_PHYIF_CTRLSTATUS_SPEED		GENMASK(18, 17)
 #define GMAC_PHYIF_CTRLSTATUS_SPEED_SHIFT	17
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
index e51c95732bad..b7db076b4214 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
@@ -456,6 +456,16 @@ static void dwmac4_set_eee_timer(struct mac_device_info *hw, int ls, int tw)
 	writel(value, ioaddr + GMAC4_LPI_TIMER_CTRL);
 }
 
+static u16 dwmac4_pcs_get_config_reg(struct mac_device_info *hw)
+{
+	void __iomem *ioaddr = hw->pcsr;
+	u32 val;
+
+	val = readl(ioaddr + GMAC_PHYIF_CONTROL_STATUS);
+
+	return FIELD_GET(GMAC_PHYIF_CTRLSTATUS_CONFIG_REG, val);
+}
+
 static void dwmac4_write_single_vlan(struct net_device *dev, u16 vid)
 {
 	void __iomem *ioaddr = (void __iomem *)dev->base_addr;
@@ -1274,6 +1284,7 @@ const struct stmmac_ops dwmac4_ops = {
 	.set_eee_pls = dwmac4_set_eee_pls,
 	.pcs_ctrl_ane = dwmac4_ctrl_ane,
 	.debug = dwmac4_debug,
+	.pcs_get_config_reg = dwmac4_pcs_get_config_reg,
 	.set_filter = dwmac4_set_filter,
 	.set_mac_loopback = dwmac4_set_mac_loopback,
 	.update_vlan_hash = dwmac4_update_vlan_hash,
@@ -1318,6 +1329,7 @@ const struct stmmac_ops dwmac410_ops = {
 	.set_eee_pls = dwmac4_set_eee_pls,
 	.pcs_ctrl_ane = dwmac4_ctrl_ane,
 	.debug = dwmac4_debug,
+	.pcs_get_config_reg = dwmac4_pcs_get_config_reg,
 	.set_filter = dwmac4_set_filter,
 	.flex_pps_config = dwmac5_flex_pps_config,
 	.set_mac_loopback = dwmac4_set_mac_loopback,
@@ -1366,6 +1378,7 @@ const struct stmmac_ops dwmac510_ops = {
 	.set_eee_pls = dwmac4_set_eee_pls,
 	.pcs_ctrl_ane = dwmac4_ctrl_ane,
 	.debug = dwmac4_debug,
+	.pcs_get_config_reg = dwmac4_pcs_get_config_reg,
 	.set_filter = dwmac4_set_filter,
 	.safety_feat_config = dwmac5_safety_feat_config,
 	.safety_feat_irq_status = dwmac5_safety_feat_irq_status,
diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.h b/drivers/net/ethernet/stmicro/stmmac/hwif.h
index ba930a87b71a..00995a0c9813 100644
--- a/drivers/net/ethernet/stmicro/stmmac/hwif.h
+++ b/drivers/net/ethernet/stmicro/stmmac/hwif.h
@@ -376,6 +376,7 @@ struct stmmac_ops {
 		      struct stmmac_extra_stats *x, u32 rx_queues,
 		      u32 tx_queues);
 	/* PCS calls */
+	u16 (*pcs_get_config_reg)(struct mac_device_info *hw);
 	void (*pcs_ctrl_ane)(void __iomem *pcsaddr, bool ane, bool srgmi_ral,
 			     bool loopback);
 	/* Safety Features */
@@ -492,6 +493,8 @@ struct stmmac_ops {
 	stmmac_do_void_callback(__priv, mac, set_eee_pls, __args)
 #define stmmac_mac_debug(__priv, __args...) \
 	stmmac_do_void_callback(__priv, mac, debug, __priv, __args)
+#define stmmac_pcs_get_config_reg(__priv, __args...) \
+	stmmac_do_callback(__priv, mac, pcs_get_config_reg, __args)
 #define stmmac_pcs_ctrl_ane(__priv, __args...) \
 	stmmac_do_void_callback(__priv, mac, pcs_ctrl_ane, __args)
 #define stmmac_safety_feat_config(__priv, __args...) \
-- 
2.43.0