root/drivers/net/dsa/b53/b53_serdes.c
// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/*
 * Northstar Plus switch SerDes/SGMII PHY main logic
 *
 * Copyright (C) 2018 Florian Fainelli <f.fainelli@gmail.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/phy.h>
#include <linux/phylink.h>
#include <net/dsa.h>

#include "b53_priv.h"
#include "b53_serdes.h"
#include "b53_regs.h"

static inline struct b53_pcs *pcs_to_b53_pcs(struct phylink_pcs *pcs)
{
        return container_of(pcs, struct b53_pcs, pcs);
}

static void b53_serdes_write_blk(struct b53_device *dev, u8 offset, u16 block,
                                 u16 value)
{
        b53_write16(dev, B53_SERDES_PAGE, B53_SERDES_BLKADDR, block);
        b53_write16(dev, B53_SERDES_PAGE, offset, value);
}

static u16 b53_serdes_read_blk(struct b53_device *dev, u8 offset, u16 block)
{
        u16 value;

        b53_write16(dev, B53_SERDES_PAGE, B53_SERDES_BLKADDR, block);
        b53_read16(dev, B53_SERDES_PAGE, offset, &value);

        return value;
}

static void b53_serdes_set_lane(struct b53_device *dev, u8 lane)
{
        if (dev->serdes_lane == lane)
                return;

        WARN_ON(lane > 1);

        b53_serdes_write_blk(dev, B53_SERDES_LANE,
                             SERDES_XGXSBLK0_BLOCKADDRESS, lane);
        dev->serdes_lane = lane;
}

static void b53_serdes_write(struct b53_device *dev, u8 lane,
                             u8 offset, u16 block, u16 value)
{
        b53_serdes_set_lane(dev, lane);
        b53_serdes_write_blk(dev, offset, block, value);
}

static u16 b53_serdes_read(struct b53_device *dev, u8 lane,
                           u8 offset, u16 block)
{
        b53_serdes_set_lane(dev, lane);
        return b53_serdes_read_blk(dev, offset, block);
}

static int b53_serdes_config(struct phylink_pcs *pcs, unsigned int neg_mode,
                             phy_interface_t interface,
                             const unsigned long *advertising,
                             bool permit_pause_to_mac)
{
        struct b53_device *dev = pcs_to_b53_pcs(pcs)->dev;
        u8 lane = pcs_to_b53_pcs(pcs)->lane;
        u16 reg;

        reg = b53_serdes_read(dev, lane, B53_SERDES_DIGITAL_CONTROL(1),
                              SERDES_DIGITAL_BLK);
        if (interface == PHY_INTERFACE_MODE_1000BASEX)
                reg |= FIBER_MODE_1000X;
        else
                reg &= ~FIBER_MODE_1000X;
        b53_serdes_write(dev, lane, B53_SERDES_DIGITAL_CONTROL(1),
                         SERDES_DIGITAL_BLK, reg);

        return 0;
}

static void b53_serdes_an_restart(struct phylink_pcs *pcs)
{
        struct b53_device *dev = pcs_to_b53_pcs(pcs)->dev;
        u8 lane = pcs_to_b53_pcs(pcs)->lane;
        u16 reg;

        reg = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_BMCR),
                              SERDES_MII_BLK);
        reg |= BMCR_ANRESTART;
        b53_serdes_write(dev, lane, B53_SERDES_MII_REG(MII_BMCR),
                         SERDES_MII_BLK, reg);
}

static void b53_serdes_get_state(struct phylink_pcs *pcs, unsigned int neg_mode,
                                 struct phylink_link_state *state)
{
        struct b53_device *dev = pcs_to_b53_pcs(pcs)->dev;
        u8 lane = pcs_to_b53_pcs(pcs)->lane;
        u16 dig, bmsr;

        dig = b53_serdes_read(dev, lane, B53_SERDES_DIGITAL_STATUS,
                              SERDES_DIGITAL_BLK);
        bmsr = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_BMSR),
                               SERDES_MII_BLK);

        switch ((dig >> SPEED_STATUS_SHIFT) & SPEED_STATUS_MASK) {
        case SPEED_STATUS_10:
                state->speed = SPEED_10;
                break;
        case SPEED_STATUS_100:
                state->speed = SPEED_100;
                break;
        case SPEED_STATUS_1000:
                state->speed = SPEED_1000;
                break;
        default:
        case SPEED_STATUS_2500:
                state->speed = SPEED_2500;
                break;
        }

        state->duplex = dig & DUPLEX_STATUS ? DUPLEX_FULL : DUPLEX_HALF;
        state->an_complete = !!(bmsr & BMSR_ANEGCOMPLETE);
        state->link = !!(dig & LINK_STATUS);
        if (dig & PAUSE_RESOLUTION_RX_SIDE)
                state->pause |= MLO_PAUSE_RX;
        if (dig & PAUSE_RESOLUTION_TX_SIDE)
                state->pause |= MLO_PAUSE_TX;
}

void b53_serdes_link_set(struct b53_device *dev, int port, unsigned int mode,
                         phy_interface_t interface, bool link_up)
{
        u8 lane = b53_serdes_map_lane(dev, port);
        u16 reg;

        if (lane == B53_INVALID_LANE)
                return;

        reg = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_BMCR),
                              SERDES_MII_BLK);
        if (link_up)
                reg &= ~BMCR_PDOWN;
        else
                reg |= BMCR_PDOWN;
        b53_serdes_write(dev, lane, B53_SERDES_MII_REG(MII_BMCR),
                         SERDES_MII_BLK, reg);
}
EXPORT_SYMBOL(b53_serdes_link_set);

static const struct phylink_pcs_ops b53_pcs_ops = {
        .pcs_get_state = b53_serdes_get_state,
        .pcs_config = b53_serdes_config,
        .pcs_an_restart = b53_serdes_an_restart,
};

void b53_serdes_phylink_get_caps(struct b53_device *dev, int port,
                                 struct phylink_config *config)
{
        u8 lane = b53_serdes_map_lane(dev, port);

        if (lane == B53_INVALID_LANE)
                return;

        switch (lane) {
        case 0:
                /* It appears lane 0 supports 2500base-X and 1000base-X */
                __set_bit(PHY_INTERFACE_MODE_2500BASEX,
                          config->supported_interfaces);
                config->mac_capabilities |= MAC_2500FD;
                fallthrough;
        case 1:
                /* It appears lane 1 only supports 1000base-X and SGMII */
                __set_bit(PHY_INTERFACE_MODE_1000BASEX,
                          config->supported_interfaces);
                __set_bit(PHY_INTERFACE_MODE_SGMII,
                          config->supported_interfaces);
                config->mac_capabilities |= MAC_1000FD;
                break;
        default:
                break;
        }
}
EXPORT_SYMBOL(b53_serdes_phylink_get_caps);

struct phylink_pcs *b53_serdes_phylink_mac_select_pcs(struct b53_device *dev,
                                                      int port,
                                                      phy_interface_t interface)
{
        u8 lane = b53_serdes_map_lane(dev, port);

        if (lane == B53_INVALID_LANE || lane >= B53_N_PCS ||
            !dev->pcs[lane].dev)
                return NULL;

        if (!phy_interface_mode_is_8023z(interface) &&
            interface != PHY_INTERFACE_MODE_SGMII)
                return NULL;

        return &dev->pcs[lane].pcs;
}
EXPORT_SYMBOL(b53_serdes_phylink_mac_select_pcs);

int b53_serdes_init(struct b53_device *dev, int port)
{
        u8 lane = b53_serdes_map_lane(dev, port);
        struct b53_pcs *pcs;
        u16 id0, msb, lsb;

        if (lane == B53_INVALID_LANE)
                return -EINVAL;

        id0 = b53_serdes_read(dev, lane, B53_SERDES_ID0, SERDES_ID0);
        msb = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_PHYSID1),
                              SERDES_MII_BLK);
        lsb = b53_serdes_read(dev, lane, B53_SERDES_MII_REG(MII_PHYSID2),
                              SERDES_MII_BLK);
        if (id0 == 0 || id0 == 0xffff) {
                dev_err(dev->dev, "SerDes not initialized, check settings\n");
                return -ENODEV;
        }

        dev_info(dev->dev,
                 "SerDes lane %d, model: %d, rev %c%d (OUI: 0x%08x)\n",
                 lane, id0 & SERDES_ID0_MODEL_MASK,
                 (id0 >> SERDES_ID0_REV_LETTER_SHIFT) + 0x41,
                 (id0 >> SERDES_ID0_REV_NUM_SHIFT) & SERDES_ID0_REV_NUM_MASK,
                 (u32)msb << 16 | lsb);

        pcs = &dev->pcs[lane];
        pcs->dev = dev;
        pcs->lane = lane;
        pcs->pcs.ops = &b53_pcs_ops;

        return 0;
}
EXPORT_SYMBOL(b53_serdes_init);

MODULE_AUTHOR("Florian Fainelli <f.fainelli@gmail.com>");
MODULE_DESCRIPTION("B53 Switch SerDes driver");
MODULE_LICENSE("Dual BSD/GPL");