Merge branch 'enable-sgmii-and-2500basex-interface-mode-switching-for-intel-platforms'

Choong Yong Liang says:

====================
Enable SGMII and 2500BASEX interface mode switching for Intel platforms

During the interface mode change, the 'phylink_major_config' function will
be triggered in phylink. The modification of the following functions will
support the switching between SGMII and 2500BASE-X interface modes for
the Intel platform:

- xpcs_switch_interface_mode: Re-initiates clause 37 auto-negotiation for
  the SGMII interface mode to perform auto-negotiation.
- mac_finish: Configures the SerDes according to the interface mode.

With the above changes, the code will work as follows during the interface
mode change. The PCS will reconfigure according to the pcs_neg_mode and the
selected interface mode. Then, the MAC driver will perform SerDes
configuration in 'mac_finish' based on the selected interface mode. During
the SerDes configuration, the selected interface mode will identify TSN
lane registers from FIA and then send IPC commands to the Power Management
Controller (PMC) through the PMC driver/API. The PMC will act as a proxy to
program the PLL registers.
====================

Link: https://patch.msgid.link/20250227121522.1802832-1-yong.liang.choong@linux.intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 98 insertions, 0 deletions

diff --git a/include/linux/platform_data/x86/intel_pmc_ipc.h b/include/linux/platform_data/x86/intel_pmc_ipc.h
new file mode 100644
index 000000000000..6e603a8c075f
--- /dev/null
+++ b/include/linux/platform_data/x86/intel_pmc_ipc.h
@@ -0,0 +1,94 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Intel Core SoC Power Management Controller Header File
+ *
+ * Copyright (c) 2025, Intel Corporation.
+ * All Rights Reserved.
+ *
+ */
+#ifndef INTEL_PMC_IPC_H
+#define INTEL_PMC_IPC_H
+#include <linux/acpi.h>
+
+#define IPC_SOC_REGISTER_ACCESS			0xAA
+#define IPC_SOC_SUB_CMD_READ			0x00
+#define IPC_SOC_SUB_CMD_WRITE			0x01
+#define PMC_IPCS_PARAM_COUNT			7
+#define VALID_IPC_RESPONSE			5
+
+struct pmc_ipc_cmd {
+	u32 cmd;
+	u32 sub_cmd;
+	u32 size;
+	u32 wbuf[4];
+};
+
+struct pmc_ipc_rbuf {
+	u32 buf[4];
+};
+
+/**
+ * intel_pmc_ipc() - PMC IPC Mailbox accessor
+ * @ipc_cmd:  Prepared input command to send
+ * @rbuf:     Allocated array for returned IPC data
+ *
+ * Return: 0 on success. Non-zero on mailbox error
+ */
+static inline int intel_pmc_ipc(struct pmc_ipc_cmd *ipc_cmd, struct pmc_ipc_rbuf *rbuf)
+{
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object params[PMC_IPCS_PARAM_COUNT] = {
+		{.type = ACPI_TYPE_INTEGER,},
+		{.type = ACPI_TYPE_INTEGER,},
+		{.type = ACPI_TYPE_INTEGER,},
+		{.type = ACPI_TYPE_INTEGER,},
+		{.type = ACPI_TYPE_INTEGER,},
+		{.type = ACPI_TYPE_INTEGER,},
+		{.type = ACPI_TYPE_INTEGER,},
+	};
+	struct acpi_object_list arg_list = { PMC_IPCS_PARAM_COUNT, params };
+	union acpi_object *obj;
+	int status;
+
+	if (!ipc_cmd || !rbuf)
+		return -EINVAL;
+
+	/*
+	 * 0: IPC Command
+	 * 1: IPC Sub Command
+	 * 2: Size
+	 * 3-6: Write Buffer for offset
+	 */
+	params[0].integer.value = ipc_cmd->cmd;
+	params[1].integer.value = ipc_cmd->sub_cmd;
+	params[2].integer.value = ipc_cmd->size;
+	params[3].integer.value = ipc_cmd->wbuf[0];
+	params[4].integer.value = ipc_cmd->wbuf[1];
+	params[5].integer.value = ipc_cmd->wbuf[2];
+	params[6].integer.value = ipc_cmd->wbuf[3];
+
+	status = acpi_evaluate_object(NULL, "\\IPCS", &arg_list, &buffer);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	obj = buffer.pointer;
+
+	if (obj && obj->type == ACPI_TYPE_PACKAGE &&
+	    obj->package.count == VALID_IPC_RESPONSE) {
+		const union acpi_object *objs = obj->package.elements;
+
+		if ((u8)objs[0].integer.value != 0)
+			return -EINVAL;
+
+		rbuf->buf[0] = objs[1].integer.value;
+		rbuf->buf[1] = objs[2].integer.value;
+		rbuf->buf[2] = objs[3].integer.value;
+		rbuf->buf[3] = objs[4].integer.value;
+	} else {
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+#endif /* INTEL_PMC_IPC_H */
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index cd0d1383df87..b6f03ab12595 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -239,6 +239,10 @@ struct plat_stmmacenet_data {
 	int (*serdes_powerup)(struct net_device *ndev, void *priv);
 	void (*serdes_powerdown)(struct net_device *ndev, void *priv);
 	void (*speed_mode_2500)(struct net_device *ndev, void *priv);
+	int (*mac_finish)(struct net_device *ndev,
+			  void *priv,
+			  unsigned int mode,
+			  phy_interface_t interface);
 	void (*ptp_clk_freq_config)(struct stmmac_priv *priv);
 	int (*init)(struct platform_device *pdev, void *priv);
 	void (*exit)(struct platform_device *pdev, void *priv);