path: root/drivers/net/dsa/microchip/ksz9477.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Microchip KSZ9477 switch driver main logic
 *
 * Copyright (C) 2017-2019 Microchip Technology Inc.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/iopoll.h>
#include <linux/platform_data/microchip-ksz.h>
#include <linux/phy.h>
#include <linux/if_bridge.h>
#include <linux/if_vlan.h>
#include <net/dsa.h>
#include <net/switchdev.h>

#include "ksz9477_reg.h"
#include "ksz_common.h"
#include "ksz9477.h"

static void ksz_cfg(struct ksz_device *dev, u32 addr, u8 bits, bool set)
{
	regmap_update_bits(ksz_regmap_8(dev), addr, bits, set ? bits : 0);
}

static void ksz_port_cfg(struct ksz_device *dev, int port, int offset, u8 bits,
			 bool set)
{
	regmap_update_bits(ksz_regmap_8(dev), PORT_CTRL_ADDR(port, offset),
			   bits, set ? bits : 0);
}

static void ksz9477_cfg32(struct ksz_device *dev, u32 addr, u32 bits, bool set)
{
	regmap_update_bits(ksz_regmap_32(dev), addr, bits, set ? bits : 0);
}

static void ksz9477_port_cfg32(struct ksz_device *dev, int port, int offset,
			       u32 bits, bool set)
{
	regmap_update_bits(ksz_regmap_32(dev), PORT_CTRL_ADDR(port, offset),
			   bits, set ? bits : 0);
}

int ksz9477_change_mtu(struct ksz_device *dev, int port, int mtu)
{
	u16 frame_size;

	if (!dsa_is_cpu_port(dev->ds, port))
		return 0;

	frame_size = mtu + VLAN_ETH_HLEN + ETH_FCS_LEN;

	return regmap_update_bits(ksz_regmap_16(dev), REG_SW_MTU__2,
				  REG_SW_MTU_MASK, frame_size);
}

/**
 * ksz9477_handle_wake_reason - Handle wake reason on a specified port.
 * @dev: The device structure.
 * @port: The port number.
 *
 * This function reads the PME (Power Management Event) status register of a
 * specified port to determine the wake reason. If there is no wake event, it
 * returns early. Otherwise, it logs the wake reason which could be due to a
 * "Magic Packet", "Link Up", or "Energy Detect" event. The PME status register
 * is then cleared to acknowledge the handling of the wake event.
 *
 * Return: 0 on success, or an error code on failure.
 */
static int ksz9477_handle_wake_reason(struct ksz_device *dev, int port)
{
	u8 pme_status;
	int ret;

	ret = ksz_pread8(dev, port, REG_PORT_PME_STATUS, &pme_status);
	if (ret)
		return ret;

	if (!pme_status)
		return 0;

	dev_dbg(dev->dev, "Wake event on port %d due to:%s%s%s\n", port,
		pme_status & PME_WOL_MAGICPKT ? " \"Magic Packet\"" : "",
		pme_status & PME_WOL_LINKUP ? " \"Link Up\"" : "",
		pme_status & PME_WOL_ENERGY ? " \"Energy detect\"" : "");

	return ksz_pwrite8(dev, port, REG_PORT_PME_STATUS, pme_status);
}

/**
 * ksz9477_get_wol - Get Wake-on-LAN settings for a specified port.
 * @dev: The device structure.
 * @port: The port number.
 * @wol: Pointer to ethtool Wake-on-LAN settings structure.
 *
 * This function checks the PME Pin Control Register to see if  PME Pin Output
 * Enable is set, indicating PME is enabled. If enabled, it sets the supported
 * and active WoL flags.
 */
void ksz9477_get_wol(struct ksz_device *dev, int port,
		     struct ethtool_wolinfo *wol)
{
	u8 pme_ctrl;
	int ret;

	if (!dev->wakeup_source)
		return;

	wol->supported = WAKE_PHY;

	/* Check if the current MAC address on this port can be set
	 * as global for WAKE_MAGIC support. The result may vary
	 * dynamically based on other ports configurations.
	 */
	if (ksz_is_port_mac_global_usable(dev->ds, port))
		wol->supported |= WAKE_MAGIC;

	ret = ksz_pread8(dev, port, REG_PORT_PME_CTRL, &pme_ctrl);
	if (ret)
		return;

	if (pme_ctrl & PME_WOL_MAGICPKT)
		wol->wolopts |= WAKE_MAGIC;
	if (pme_ctrl & (PME_WOL_LINKUP | PME_WOL_ENERGY))
		wol->wolopts |= WAKE_PHY;
}

/**
 * ksz9477_set_wol - Set Wake-on-LAN settings for a specified port.
 * @dev: The device structure.
 * @port: The port number.
 * @wol: Pointer to ethtool Wake-on-LAN settings structure.
 *
 * This function configures Wake-on-LAN (WoL) settings for a specified port.
 * It validates the provided WoL options, checks if PME is enabled via the
 * switch's PME Pin Control Register, clears any previous wake reasons,
 * and sets the Magic Packet flag in the port's PME control register if
 * specified.
 *
 * Return: 0 on success, or other error codes on failure.
 */
int ksz9477_set_wol(struct ksz_device *dev, int port,
		    struct ethtool_wolinfo *wol)
{
	u8 pme_ctrl = 0, pme_ctrl_old = 0;
	bool magic_switched_off;
	bool magic_switched_on;
	int ret;

	if (wol->wolopts & ~(WAKE_PHY | WAKE_MAGIC))
		return -EINVAL;

	if (!dev->wakeup_source)
		return -EOPNOTSUPP;

	ret = ksz9477_handle_wake_reason(dev, port);
	if (ret)
		return ret;

	if (wol->wolopts & WAKE_MAGIC)
		pme_ctrl |= PME_WOL_MAGICPKT;
	if (wol->wolopts & WAKE_PHY)
		pme_ctrl |= PME_WOL_LINKUP | PME_WOL_ENERGY;

	ret = ksz_pread8(dev, port, REG_PORT_PME_CTRL, &pme_ctrl_old);
	if (ret)
		return ret;

	if (pme_ctrl_old == pme_ctrl)
		return 0;

	magic_switched_off = (pme_ctrl_old & PME_WOL_MAGICPKT) &&
			    !(pme_ctrl & PME_WOL_MAGICPKT);
	magic_switched_on = !(pme_ctrl_old & PME_WOL_MAGICPKT) &&
			    (pme_ctrl & PME_WOL_MAGICPKT);

	/* To keep reference count of MAC address, we should do this
	 * operation only on change of WOL settings.
	 */
	if (magic_switched_on) {
		ret = ksz_switch_macaddr_get(dev->ds, port, NULL);
		if (ret)
			return ret;
	} else if (magic_switched_off) {
		ksz_switch_macaddr_put(dev->ds);
	}

	ret = ksz_pwrite8(dev, port, REG_PORT_PME_CTRL, pme_ctrl);
	if (ret) {
		if (magic_switched_on)
			ksz_switch_macaddr_put(dev->ds);
		return ret;
	}

	return 0;
}

/**
 * ksz9477_wol_pre_shutdown - Prepares the switch device for shutdown while
 *                            considering Wake-on-LAN (WoL) settings.
 * @dev: The switch device structure.
 * @wol_enabled: Pointer to a boolean which will be set to true if WoL is
 *               enabled on any port.
 *
 * This function prepares the switch device for a safe shutdown while taking
 * into account the Wake-on-LAN (WoL) settings on the user ports. It updates
 * the wol_enabled flag accordingly to reflect whether WoL is active on any
 * port.
 */
void ksz9477_wol_pre_shutdown(struct ksz_device *dev, bool *wol_enabled)
{
	struct dsa_port *dp;
	int ret;

	*wol_enabled = false;

	if (!dev->wakeup_source)
		return;

	dsa_switch_for_each_user_port(dp, dev->ds) {
		u8 pme_ctrl = 0;

		ret = ksz_pread8(dev, dp->index, REG_PORT_PME_CTRL, &pme_ctrl);
		if (!ret && pme_ctrl)
			*wol_enabled = true;

		/* make sure there are no pending wake events which would
		 * prevent the device from going to sleep/shutdown.
		 */
		ksz9477_handle_wake_reason(dev, dp->index);
	}

	/* Now we are save to enable PME pin. */
	if (*wol_enabled)
		ksz_write8(dev, REG_SW_PME_CTRL, PME_ENABLE);
}

static int ksz9477_wait_vlan_ctrl_ready(struct ksz_device *dev)
{
	unsigned int val;

	return regmap_read_poll_timeout(ksz_regmap_8(dev), REG_SW_VLAN_CTRL,
					val, !(val & VLAN_START), 10, 1000);
}

static int ksz9477_get_vlan_table(struct ksz_device *dev, u16 vid,
				  u32 *vlan_table)
{
	int ret;

	mutex_lock(&dev->vlan_mutex);

	ksz_write16(dev, REG_SW_VLAN_ENTRY_INDEX__2, vid & VLAN_INDEX_M);
	ksz_write8(dev, REG_SW_VLAN_CTRL, VLAN_READ | VLAN_START);

	/* wait to be cleared */
	ret = ksz9477_wait_vlan_ctrl_ready(dev);
	if (ret) {
		dev_dbg(dev->dev, "Failed to read vlan table\n");
		goto exit;
	}

	ksz_read32(dev, REG_SW_VLAN_ENTRY__4, &vlan_table[0]);
	ksz_read32(dev, REG_SW_VLAN_ENTRY_UNTAG__4, &vlan_table[1]);
	ksz_read32(dev, REG_SW_VLAN_ENTRY_PORTS__4, &vlan_table[2]);

	ksz_write8(dev, REG_SW_VLAN_CTRL, 0);

exit:
	mutex_unlock(&dev->vlan_mutex);

	return ret;
}

static int ksz9477_set_vlan_table(struct ksz_device *dev, u16 vid,
				  u32 *vlan_table)
{
	int ret;

	mutex_lock(&dev->vlan_mutex);

	ksz_write32(dev, REG_SW_VLAN_ENTRY__4, vlan_table[0]);
	ksz_write32(dev, REG_SW_VLAN_ENTRY_UNTAG__4, vlan_table[1]);
	ksz_write32(dev, REG