Merge branch 'pcs-xpcs-mmap' into main

Serge Semin <fancer says:

====================
net: pcs: xpcs: Add memory-mapped device support

The main goal of this series is to extend the DW XPCS device support in
the kernel. Particularly the patchset adds a support of the DW XPCS
device with the MCI/APB3 IO interface registered as a platform device. In
order to have them utilized by the DW XPCS core the fwnode-based DW XPCS
descriptor creation procedure has been introduced. Finally the STMMAC
driver has been altered to support the DW XPCS passed via the 'pcs-handle'
property.

Note the series has been significantly re-developed since v1. So I even
had to change the subject. Anyway I've done my best to take all the noted
into account.

The series traditionally starts with a set of the preparation patches.
First one just moves the generic DW XPCS IDs macros from the internal
header file to the external one where some other IDs also reside. Second
patch splits up the xpcs_create() method to a set of the coherent
sub-functions for the sake of the further easier updates and to have it
looking less complicated. The goal of the next three patches is to extend
the DW XPCS ID management code by defining a new dw_xpcs_info structure
with both PCS and PMA IDs.

The next two patches provide the DW XPCS device DT-bindings and the
respective platform-device driver for the memory-mapped DW XPCS devices.
Besides the later patch makes use of the introduced dw_xpcs_info structure
to pre-define the DW XPCS IDs based on the platform-device compatible
string. Thus if there is no way to auto-identify the XPCS device
capabilities it can be done based on the custom device IDs passed via the
MDIO-device platform data.

Final DW XPCS driver change is about adding a new method of the DW XPCS
descriptor creation. The xpcs_create_fwnode() function has been introduced
with the same semantics as a similar method recently added to the Lynx PCS
driver. It's supposed to be called with the fwnode pointing to the DW XPCS
device node, for which the XPCS descriptor will be created.

The series is terminated with two STMMAC driver patches. The former one
simplifies the DW XPCS descriptor registration procedure by dropping the
MDIO-bus scanning and creating the descriptor for the particular device
address. The later patch alters the STMMAC PCS setup method so one would
support the DW XPCS specified via the "pcs-handle" property.

That's it for now. Thanks for review in advance. Any tests are very
welcome. After this series is merged in, I'll submit another one which
adds the generic 10GBase-R and 10GBase-X interfaces support to the STMMAC
and DW XPCS driver with the proper CSRs re-initialization, PMA
initialization and reference clock selection as it's described in the
Synopsys DW XPCS HW manual.

Link: https://lore.kernel.org/netdev/[email protected]
Changelog v2:
- Drop the patches:
  [PATCH net-next 01/16] net: pcs: xpcs: Drop sentinel entry from 2500basex ifaces list
  [PATCH net-next 02/16] net: pcs: xpcs: Drop redundant workqueue.h include directive
  [PATCH net-next 03/16] net: pcs: xpcs: Return EINVAL in the internal methods
  [PATCH net-next 04/16] net: pcs: xpcs: Explicitly return error on caps validation
  as ones have already been merged into the kernel repo:
Link: https://lore.kernel.org/netdev/[email protected]/
- Drop the patches:
  [PATCH net-next 14/16] net: stmmac: Pass netdev to XPCS setup function
  [PATCH net-next 15/16] net: stmmac: Add dedicated XPCS cleanup method
  as ones have already been merged into the kernel repo:
Link: https://lore.kernel.org/netdev/[email protected]/
- Drop the patch:
  [PATCH net-next 06/16] net: pcs: xpcs: Avoid creating dummy XPCS MDIO device
  [PATCH net-next 09/16] net: mdio: Add Synopsys DW XPCS management interface support
  [PATCH net-next 11/16] net: pcs: xpcs: Change xpcs_create_mdiodev() suffix to "byaddr"
  [PATCH net-next 13/16] net: stmmac: intel: Register generic MDIO device
  as no longer relevant.
- Add new patches:
  [PATCH net-next v2 03/10] net: pcs: xpcs: Convert xpcs_id to dw_xpcs_desc
  [PATCH net-next v2 04/10] net: pcs: xpcs: Convert xpcs_compat to dw_xpcs_compat
  [PATCH net-next v2 05/10] net: pcs: xpcs: Introduce DW XPCS info structure
  [PATCH net-next v2 09/10] net: stmmac: Create DW XPCS device with particular address
- Use the xpcs_create_fwnode() function name and semantics similar to the
  Lynx PCS driver.
- Add kdoc describing the DW XPCS registration functions.
- Convert the memory-mapped DW XPCS device driver to being the
  platform-device driver.
- Convert the DW XPCS DT-bindings to defining both memory-mapped and MDIO
  devices.
- Drop inline'es from the methods statically defined in *.c. (@maxime)
- Preserve the strict refcount-ing pattern. (@russell)

Link: https://lore.kernel.org/netdev/[email protected]/
Changelov v3:
- Implement the ordered clocks constraint. (@rob)
- Convert xpcs_plat_pm_ops to being defined as static. (@simon)
- Add the "@interface" argument kdoc to the xpcs_create_mdiodev()
  function. (@simon)
- Fix the "@fwnode" argument name in the xpcs_create_fwnode() method kdoc.
  (@simon)
- Move the return value descriptions to the "Return:" section of the
  xpcs_create_mdiodev() and xpcs_create_fwnode() kdoc. (@simon)
- Drop stmmac_mdio_bus_data::has_xpcs flag and define the PCS-address
  mask with particular XPCS address instead.

Link: https://lore.kernel.org/netdev/[email protected]/
Changelog v4:
- Make sure the series is applicable to the net-next tree. (@vladimir)
- Rename entry to desc in the xpcs_init_id() method. (@andrew)
- Add a comment to the clock-names property constraint about the
  oneOf-subschemas applicability. (@conor)
- Convert "pclk" clock name to "csr" to match the DW XPCS IP-core
  input signal name. (@rob)
====================

Signed-off-by: David S. Miller <[email protected]>

Author: davem330

Documentation/devicetree/bindings/net/pcs/snps,dw-xpcs.yaml

@@ -0,0 +1,136 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/pcs/snps,dw-xpcs.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Synopsys DesignWare Ethernet PCS
+
+maintainers:
+  - Serge Semin <[email protected]>
+
+description:
+  Synopsys DesignWare Ethernet Physical Coding Sublayer provides an interface
+  between Media Access Control and Physical Medium Attachment Sublayer through
+  the Media Independent Interface (XGMII, USXGMII, XLGMII, GMII, etc)
+  controlled by means of the IEEE std. Clause 45 registers set. The PCS can be
+  optionally synthesized with a vendor-specific interface connected to
+  Synopsys PMA (also called DesignWare Consumer/Enterprise PHY) although in
+  general it can be used to communicate with any compatible PHY.
+
+  The PCS CSRs can be accessible either over the Ethernet MDIO bus or directly
+  by means of the APB3/MCI interfaces. In the later case the XPCS can be mapped
+  right to the system IO memory space.
+
+properties:
+  compatible:
+    oneOf:
+      - description: Synopsys DesignWare XPCS with none or unknown PMA
+        const: snps,dw-xpcs
+      - description: Synopsys DesignWare XPCS with Consumer Gen1 3G PMA
+        const: snps,dw-xpcs-gen1-3g
+      - description: Synopsys DesignWare XPCS with Consumer Gen2 3G PMA
+        const: snps,dw-xpcs-gen2-3g
+      - description: Synopsys DesignWare XPCS with Consumer Gen2 6G PMA
+        const: snps,dw-xpcs-gen2-6g
+      - description: Synopsys DesignWare XPCS with Consumer Gen4 3G PMA
+        const: snps,dw-xpcs-gen4-3g
+      - description: Synopsys DesignWare XPCS with Consumer Gen4 6G PMA
+        const: snps,dw-xpcs-gen4-6g
+      - description: Synopsys DesignWare XPCS with Consumer Gen5 10G PMA
+        const: snps,dw-xpcs-gen5-10g
+      - description: Synopsys DesignWare XPCS with Consumer Gen5 12G PMA
+        const: snps,dw-xpcs-gen5-12g
+
+  reg:
+    items:
+      - description:
+          In case of the MDIO management interface this just a 5-bits ID
+          of the MDIO bus device. If DW XPCS CSRs space is accessed over the
+          MCI or APB3 management interfaces, then the space mapping can be
+          either 'direct' or 'indirect'. In the former case all Clause 45
+          registers are contiguously mapped within the address space
+          MMD '[20:16]', Reg '[15:0]'. In the later case the space is divided
+          to the multiple 256 register sets. There is a special viewport CSR
+          which is responsible for the set selection. The upper part of
+          the CSR address MMD+REG[20:8] is supposed to be written in there
+          so the corresponding subset would be mapped to the lowest 255 CSRs.
+
+  reg-names:
+    items:
+      - enum: [ direct, indirect ]
+
+  reg-io-width:
+    description:
+      The way the CSRs are mapped to the memory is platform depended. Since
+      each Clause 45 CSR is of 16-bits wide the access instructions must be
+      two bytes aligned at least.
+    default: 2
+    enum: [ 2, 4 ]
+
+  interrupts:
+    description:
+      System interface interrupt output (sbd_intr_o) indicating Clause 73/37
+      auto-negotiation events':' Page received, AN is completed or incompatible
+      link partner.
+    maxItems: 1
+
+  clocks:
+    description:
+      The MCI and APB3 interfaces are supposed to be equipped with a clock
+      source connected to the clk_csr_i line.
+
+      PCS/PMA layer can be clocked by an internal reference clock source
+      (phyN_core_refclk) or by an externally connected (phyN_pad_refclk) clock
+      generator. Both clocks can be supplied at a time.
+    minItems: 1
+    maxItems: 3
+
+  clock-names:
+    oneOf:
+      - minItems: 1
+        items: # MDIO
+          - enum: [core, pad]
+          - const: pad
+      - minItems: 1
+        items: # MCI or APB
+          - const: csr
+          - enum: [core, pad]
+          - const: pad
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    ethernet-pcs@1f05d000 {
+      compatible = "snps,dw-xpcs";
+      reg = <0x1f05d000 0x1000>;
+      reg-names = "indirect";
+
+      reg-io-width = <4>;
+
+      interrupts = <79 IRQ_TYPE_LEVEL_HIGH>;
+
+      clocks = <&ccu_pclk>, <&ccu_core>, <&ccu_pad>;
+      clock-names = "csr", "core", "pad";
+    };
+  - |
+    mdio-bus {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      ethernet-pcs@0 {
+        compatible = "snps,dw-xpcs";
+        reg = <0>;
+
+        clocks = <&ccu_core>, <&ccu_pad>;
+        clock-names = "core", "pad";
+      };
+    };
+...

drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c

@@ -595,7 +595,7 @@ static int intel_mgbe_common_data(struct pci_dev *pdev,
 	/* Intel mgbe SGMII interface uses pcs-xcps */
 	if (plat->phy_interface == PHY_INTERFACE_MODE_SGMII ||
 	    plat->phy_interface == PHY_INTERFACE_MODE_1000BASEX) {
-		plat->mdio_bus_data->has_xpcs = true;
+		plat->mdio_bus_data->pcs_mask = BIT(INTEL_MGBE_XPCS_ADDR);
 		plat->mdio_bus_data->default_an_inband = true;
 		plat->select_pcs = intel_mgbe_select_pcs;
 	}

drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c

@@ -497,35 +497,33 @@ int stmmac_mdio_reset(struct mii_bus *bus)
 
 int stmmac_pcs_setup(struct net_device *ndev)
 {
+	struct fwnode_handle *devnode, *pcsnode;
 	struct dw_xpcs *xpcs = NULL;
 	struct stmmac_priv *priv;
-	int ret = -ENODEV;
-	int mode, addr;
+	int addr, mode, ret;
 
 	priv = netdev_priv(ndev);
 	mode = priv->plat->phy_interface;
+	devnode = priv->plat->port_node;
 
 	if (priv->plat->pcs_init) {
 		ret = priv->plat->pcs_init(priv);
+	} else if (fwnode_property_present(devnode, "pcs-handle")) {
+		pcsnode = fwnode_find_reference(devnode, "pcs-handle", 0);
+		xpcs = xpcs_create_fwnode(pcsnode, mode);
+		fwnode_handle_put(pcsnode);
+		ret = PTR_ERR_OR_ZERO(xpcs);
 	} else if (priv->plat->mdio_bus_data &&
-		   priv->plat->mdio_bus_data->has_xpcs) {
-		/* Try to probe the XPCS by scanning all addresses */
-		for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
-			xpcs = xpcs_create_mdiodev(priv->mii, addr, mode);
-			if (IS_ERR(xpcs))
-				continue;
-
-			ret = 0;
-			break;
-		}
+		   priv->plat->mdio_bus_data->pcs_mask) {
+		addr = ffs(priv->plat->mdio_bus_data->pcs_mask) - 1;
+		xpcs = xpcs_create_mdiodev(priv->mii, addr, mode);
+		ret = PTR_ERR_OR_ZERO(xpcs);
 	} else {
 		return 0;
 	}
 
-	if (ret) {
-		dev_warn(priv->device, "No xPCS found\n");
-		return ret;
-	}
+	if (ret)
+		return dev_err_probe(priv->device, ret, "No xPCS found\n");
 
 	priv->hw->xpcs = xpcs;
 
@@ -610,7 +608,7 @@ int stmmac_mdio_register(struct net_device *ndev)
 	snprintf(new_bus->id, MII_BUS_ID_SIZE, "%s-%x",
 		 new_bus->name, priv->plat->bus_id);
 	new_bus->priv = ndev;
-	new_bus->phy_mask = mdio_bus_data->phy_mask;
+	new_bus->phy_mask = mdio_bus_data->phy_mask | mdio_bus_data->pcs_mask;
 	new_bus->parent = priv->device;
 
 	err = of_mdiobus_register(new_bus, mdio_node);

drivers/net/pcs/Kconfig

@@ -6,11 +6,11 @@
 menu "PCS device drivers"
 
 config PCS_XPCS
-	tristate
+	tristate "Synopsys DesignWare Ethernet XPCS"
 	select PHYLINK
 	help
-	  This module provides helper functions for Synopsys DesignWare XPCS
-	  controllers.
+	  This module provides a driver and helper functions for Synopsys
+	  DesignWare XPCS controllers.
 
 config PCS_LYNX
 	tristate

drivers/net/pcs/Makefile

@@ -1,7 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0
 # Makefile for Linux PCS drivers
 
-pcs_xpcs-$(CONFIG_PCS_XPCS)	:= pcs-xpcs.o pcs-xpcs-nxp.o pcs-xpcs-wx.o
+pcs_xpcs-$(CONFIG_PCS_XPCS)	:= pcs-xpcs.o pcs-xpcs-plat.o \
+				   pcs-xpcs-nxp.o pcs-xpcs-wx.o
 
 obj-$(CONFIG_PCS_XPCS)		+= pcs_xpcs.o
 obj-$(CONFIG_PCS_LYNX)		+= pcs-lynx.o