lan937x_main.c

// SPDX-License-Identifier: GPL-2.0
/* Microchip LAN937X switch driver main logic
 * Copyright (C) 2019-2022 Microchip Technology Inc.
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/iopoll.h>
#include <linux/phy.h>
#include <linux/of_net.h>
#include <linux/of_mdio.h>
#include <linux/if_bridge.h>
#include <linux/if_vlan.h>
#include <linux/math.h>
#include <net/dsa.h>
#include <net/switchdev.h>

#include "lan937x_reg.h"
#include "ksz_common.h"
#include "lan937x.h"

static int lan937x_cfg(struct ksz_device *dev, u32 addr, u8 bits, bool set)
{
	return regmap_update_bits(dev->regmap[0], addr, bits, set ? bits : 0);
}

static int lan937x_port_cfg(struct ksz_device *dev, int port, int offset,
			    u8 bits, bool set)
{
	return regmap_update_bits(dev->regmap[0], PORT_CTRL_ADDR(port, offset),
				  bits, set ? bits : 0);
}

static int lan937x_enable_spi_indirect_access(struct ksz_device *dev)
{
	u16 data16;
	int ret;

	/* Enable Phy access through SPI */
	ret = lan937x_cfg(dev, REG_GLOBAL_CTRL_0, SW_PHY_REG_BLOCK, false);
	if (ret < 0)
		return ret;

	ret = ksz_read16(dev, REG_VPHY_SPECIAL_CTRL__2, &data16);
	if (ret < 0)
		return ret;

	/* Allow SPI access */
	data16 |= VPHY_SPI_INDIRECT_ENABLE;

	return ksz_write16(dev, REG_VPHY_SPECIAL_CTRL__2, data16);
}

static int lan937x_vphy_ind_addr_wr(struct ksz_device *dev, int addr, int reg)
{
	u16 addr_base = REG_PORT_T1_PHY_CTRL_BASE;
	u16 temp;

	/* get register address based on the logical port */
	temp = PORT_CTRL_ADDR(addr, (addr_base + (reg << 2)));

	return ksz_write16(dev, REG_VPHY_IND_ADDR__2, temp);
}

static int lan937x_internal_phy_write(struct ksz_device *dev, int addr, int reg,
				      u16 val)
{
	unsigned int value;
	int ret;

	/* Check for internal phy port */
	if (!dev->info->internal_phy[addr])
		return -EOPNOTSUPP;

	ret = lan937x_vphy_ind_addr_wr(dev, addr, reg);
	if (ret < 0)
		return ret;

	/* Write the data to be written to the VPHY reg */
	ret = ksz_write16(dev, REG_VPHY_IND_DATA__2, val);
	if (ret < 0)
		return ret;

	/* Write the Write En and Busy bit */
	ret = ksz_write16(dev, REG_VPHY_IND_CTRL__2,
			  (VPHY_IND_WRITE | VPHY_IND_BUSY));
	if (ret < 0)
		return ret;

	ret = regmap_read_poll_timeout(dev->regmap[1], REG_VPHY_IND_CTRL__2,
				       value, !(value & VPHY_IND_BUSY), 10,
				       1000);
	if (ret < 0) {
		dev_err(dev->dev, "Failed to write phy register\n");
		return ret;
	}

	return 0;
}

static int lan937x_internal_phy_read(struct ksz_device *dev, int addr, int reg,
				     u16 *val)
{
	unsigned int value;
	int ret;

	/* Check for internal phy port, return 0xffff for non-existent phy */
	if (!dev->info->internal_phy[addr])
		return 0xffff;

	ret = lan937x_vphy_ind_addr_wr(dev, addr, reg);
	if (ret < 0)
		return ret;

	/* Write Read and Busy bit to start the transaction */
	ret = ksz_write16(dev, REG_VPHY_IND_CTRL__2, VPHY_IND_BUSY);
	if (ret < 0)
		return ret;

	ret = regmap_read_poll_timeout(dev->regmap[1], REG_VPHY_IND_CTRL__2,
				       value, !(value & VPHY_IND_BUSY), 10,
				       1000);
	if (ret < 0) {
		dev_err(dev->dev, "Failed to read phy register\n");
		return ret;
	}

	/* Read the VPHY register which has the PHY data */
	return ksz_read16(dev, REG_VPHY_IND_DATA__2, val);
}

void lan937x_r_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 *data)
{
	lan937x_internal_phy_read(dev, addr, reg, data);
}

void lan937x_w_phy(struct ksz_device *dev, u16 addr, u16 reg, u16 val)
{
	lan937x_internal_phy_write(dev, addr, reg, val);
}

static int lan937x_sw_mdio_read(struct mii_bus *bus, int addr, int regnum)
{
	struct ksz_device *dev = bus->priv;
	u16 val;
	int ret;

	if (regnum & MII_ADDR_C45)
		return -EOPNOTSUPP;

	ret = lan937x_internal_phy_read(dev, addr, regnum, &val);
	if (ret < 0)
		return ret;

	return val;
}

static int lan937x_sw_mdio_write(struct mii_bus *bus, int addr, int regnum,
				 u16 val)
{
	struct ksz_device *dev = bus->priv;

	if (regnum & MII_ADDR_C45)
		return -EOPNOTSUPP;

	return lan937x_internal_phy_write(dev, addr, regnum, val);
}

static int lan937x_mdio_register(struct ksz_device *dev)
{
	struct dsa_switch *ds = dev->ds;
	struct device_node *mdio_np;
	struct mii_bus *bus;
	int ret;

	mdio_np = of_get_child_by_name(dev->dev->of_node, "mdio");
	if (!mdio_np) {
		dev_err(ds->dev, "no MDIO bus node\n");
		return -ENODEV;
	}

	bus = devm_mdiobus_alloc(ds->dev);
	if (!bus) {
		of_node_put(mdio_np);
		return -ENOMEM;
	}

	bus->priv = dev;
	bus->read = lan937x_sw_mdio_read;
	bus->write = lan937x_sw_mdio_write;
	bus->name = "lan937x slave smi";
	snprintf(bus->id, MII_BUS_ID_SIZE, "SMI-%d", ds->index);
	bus->parent = ds->dev;
	bus->phy_mask = ~ds->phys_mii_mask;

	ds->slave_mii_bus = bus;

	ret = devm_of_mdiobus_register(ds->dev, bus, mdio_np);
	if (ret) {
		dev_err(ds->dev, "unable to register MDIO bus %s\n",
			bus->id);
	}

	of_node_put(mdio_np);

	return ret;
}

int lan937x_reset_switch(struct ksz_device *dev)
{
	u32 data32;
	int ret;

	/* reset switch */
	ret = lan937x_cfg(dev, REG_SW_OPERATION, SW_RESET, true);
	if (ret < 0)
		return ret;

	/* Enable Auto Aging */
	ret = lan937x_cfg(dev, REG_SW_LUE_CTRL_1, SW_LINK_AUTO_AGING, true);
	if (ret < 0)
		return ret;

	/* disable interrupts */
	ret = ksz_write32(dev, REG_SW_INT_MASK__4, SWITCH_INT_MASK);
	if (ret < 0)
		return ret;

	ret = ksz_write32(dev, REG_SW_PORT_INT_MASK__4, 0xFF);
	if (ret < 0)
		return ret;

	return ksz_read32(dev, REG_SW_PORT_INT_STATUS__4, &data32);
}

void lan937x_port_setup(struct ksz_device *dev, int port, bool cpu_port)
{
	const u32 *masks = dev->info->masks;
	const u16 *regs = dev->info->regs;
	struct dsa_switch *ds = dev->ds;
	u8 member;

	/* enable tag tail for host port */
	if (cpu_port)
		lan937x_port_cfg(dev, port, REG_PORT_CTRL_0,
				 PORT_TAIL_TAG_ENABLE, true);

	/* disable frame check length field */
	lan937x_port_cfg(dev, port, REG_PORT_MAC_CTRL_0, PORT_CHECK_LENGTH,
			 false);

	/* set back pressure for half duplex */
	lan937x_port_cfg(dev, port, REG_PORT_MAC_CTRL_1, PORT_BACK_PRESSURE,
			 true);

	/* enable 802.1p priority */
	lan937x_port_cfg(dev, port, P_PRIO_CTRL, PORT_802_1P_PRIO_ENABLE, true);

	if (!dev->info->internal_phy[port])
		lan937x_port_cfg(dev, port, regs[P_XMII_CTRL_0],
				 masks[P_MII_TX_FLOW_CTRL] |
				 masks[P_MII_RX_FLOW_CTRL],
				 true);

	if (cpu_port)
		member = dsa_user_ports(ds);
	else
		member = BIT(dsa_upstream_port(ds, port));

	dev->dev_ops->cfg_port_member(dev, port, member);
}

void lan937x_config_cpu_port(struct dsa_switch *ds)
{
	struct ksz_device *dev = ds->priv;
	struct dsa_port *dp;

	dsa_switch_for_each_cpu_port(dp, ds) {
		if (dev->info->cpu_ports & (1 << dp->index)) {
			dev->cpu_port = dp->index;

			/* enable cpu port */
			lan937x_port_setup(dev, dp->index, true);
		}
	}

	dsa_switch_for_each_user_port(dp, ds) {
		ksz_port_stp_state_set(ds, dp->index, BR_STATE_DISABLED);
	}
}

int lan937x_change_mtu(struct ksz_device *dev, int port, int new_mtu)
{
	struct dsa_switch *ds = dev->ds;
	int ret;

	new_mtu += VLAN_ETH_HLEN + ETH_FCS_LEN;

	if (dsa_is_cpu_port(ds, port))
		new_mtu += LAN937X_TAG_LEN;

	if (new_mtu >= FR_MIN_SIZE)
		ret = lan937x_port_cfg(dev, port, REG_PORT_MAC_CTRL_0,
				       PORT_JUMBO_PACKET, true);
	else
		ret = lan937x_port_cfg(dev, port, REG_PORT_MAC_CTRL_0,
				       PORT_JUMBO_PACKET, false);
	if (ret < 0) {
		dev_err(ds->dev, "failed to enable jumbo\n");
		return ret;
	}

	/* Write the frame size in PORT_MAX_FR_SIZE register */
	ksz_pwrite16(dev, port, PORT_MAX_FR_SIZE, new_mtu);

	return 0;
}

static void lan937x_mac_config(struct ksz_device *dev, int port,
			       phy_interface_t interface)
{
	u8 data8;

	ksz_pread8(dev, port, REG_PORT_XMII_CTRL_1, &data8);

	/* clear MII selection & set it based on interface later */
	data8 &= ~PORT_MII_SEL_M;

	/* configure MAC based on interface */
	switch (interface) {
	case PHY_INTERFACE_MODE_MII:
		ksz_set_gbit(dev, port, false);
		data8 |= PORT_MII_SEL;
		break;
	case PHY_INTERFACE_MODE_RMII:
		ksz_set_gbit(dev, port, false);
		data8 |= PORT_RMII_SEL;
		break;
	default:
		dev_err(dev->dev, "Unsupported interface '%s' for port %d\n",
			phy_modes(interface), port);
		return;
	}

	/* Write the updated value */
	ksz_pwrite8(dev, port, REG_PORT_XMII_CTRL_1, data8);
}

void lan937x_phylink_get_caps(struct ksz_device *dev, int port,
			      struct phylink_config *config)
{
	config->mac_capabilities = MAC_100FD;

	if (dev->info->supports_rgmii[port]) {
		/* MII/RMII/RGMII ports */
		config->mac_capabilities |= MAC_ASYM_PAUSE | MAC_SYM_PAUSE |
					    MAC_100HD | MAC_10 | MAC_1000FD;
	}
}

void lan937x_phylink_mac_config(struct ksz_device *dev, int port,
				unsigned int mode,
				const struct phylink_link_state *state)
{
	/* Internal PHYs */
	if (dev->info->internal_phy[port])
		return;

	if (phylink_autoneg_inband(mode)) {
		dev_err(dev->dev, "In-band AN not supported!\n");
		return;
	}

	lan937x_mac_config(dev, port, state->interface);
}

int lan937x_setup(struct dsa_switch *ds)
{
	struct ksz_device *dev = ds->priv;
	int ret;

	/* enable Indirect Access from SPI to the VPHY registers */
	ret = lan937x_enable_spi_indirect_access(dev);
	if (ret < 0) {
		dev_err(dev->dev, "failed to enable spi indirect access");
		return ret;
	}

	ret = lan937x_mdio_register(dev);
	if (ret < 0) {
		dev_err(dev->dev, "failed to register the mdio");
		return ret;
	}

	/* The VLAN aware is a global setting. Mixed vlan
	 * filterings are not supported.
	 */
	ds->vlan_filtering_is_global = true;

	/* Enable aggressive back off for half duplex & UNH mode */
	lan937x_cfg(dev, REG_SW_MAC_CTRL_0,
		    (SW_PAUSE_UNH_MODE | SW_NEW_BACKOFF | SW_AGGR_BACKOFF),
		    true);

	/* If NO_EXC_COLLISION_DROP bit is set, the switch will not drop
	 * packets when 16 or more collisions occur
	 */
	lan937x_cfg(dev, REG_SW_MAC_CTRL_1, NO_EXC_COLLISION_DROP, true);

	/* enable global MIB counter freeze function */
	lan937x_cfg(dev, REG_SW_MAC_CTRL_6, SW_MIB_COUNTER_FREEZE, true);

	/* disable CLK125 & CLK25, 1: disable, 0: enable */
	lan937x_cfg(dev, REG_SW_GLOBAL_OUTPUT_CTRL__1,
		    (SW_CLK125_ENB | SW_CLK25_ENB), true);

	return 0;
}

int lan937x_switch_init(struct ksz_device *dev)
{
	dev->port_mask = (1 << dev->info->port_cnt) - 1;

	return 0;
}

void lan937x_switch_exit(struct ksz_device *dev)
{
	lan937x_reset_switch(dev);
}

MODULE_AUTHOR("Arun Ramadoss <arun.ramadoss@microchip.com>");
MODULE_DESCRIPTION("Microchip LAN937x Series Switch DSA Driver");
MODULE_LICENSE("GPL");