// SPDX-License-Identifier: GPL-2.0-only
/*
 * FCC driver for Motorola MPC82xx (PQ2).
 *
 * Copyright (c) 2003 Intracom S.A.
 *  by Pantelis Antoniou <panto@intracom.gr>
 *
 * 2005 (c) MontaVista Software, Inc.
 * Vitaly Bordug <vbordug@ru.mvista.com>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/ethtool.h>
#include <linux/bitops.h>
#include <linux/fs.h>
#include <linux/platform_device.h>
#include <linux/phy.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/gfp.h>
#include <linux/pgtable.h>

#include <asm/immap_cpm2.h>
#include <asm/cpm2.h>

#include <asm/irq.h>
#include <linux/uaccess.h>

#include "fs_enet.h"

/*************************************************/

/* FCC access macros */

/* write, read, set bits, clear bits */
#define W32(_p, _m, _v) out_be32(&(_p)->_m, (_v))
#define R32(_p, _m)     in_be32(&(_p)->_m)
#define S32(_p, _m, _v) W32(_p, _m, R32(_p, _m) | (_v))
#define C32(_p, _m, _v) W32(_p, _m, R32(_p, _m) & ~(_v))

#define W16(_p, _m, _v) out_be16(&(_p)->_m, (_v))
#define R16(_p, _m)     in_be16(&(_p)->_m)
#define S16(_p, _m, _v) W16(_p, _m, R16(_p, _m) | (_v))
#define C16(_p, _m, _v) W16(_p, _m, R16(_p, _m) & ~(_v))

#define W8(_p, _m, _v)  out_8(&(_p)->_m, (_v))
#define R8(_p, _m)      in_8(&(_p)->_m)
#define S8(_p, _m, _v)  W8(_p, _m, R8(_p, _m) | (_v))
#define C8(_p, _m, _v)  W8(_p, _m, R8(_p, _m) & ~(_v))

/*************************************************/

#define FCC_MAX_MULTICAST_ADDRS 64

#define mk_mii_read(REG)        (0x60020000 | ((REG & 0x1f) << 18))
#define mk_mii_write(REG, VAL)  (0x50020000 | ((REG & 0x1f) << 18) | (VAL & 0xffff))
#define mk_mii_end              0

#define MAX_CR_CMD_LOOPS        10000

static inline int fcc_cr_cmd(struct fs_enet_private *fep, u32 op)
{
        const struct fs_platform_info *fpi = fep->fpi;

        return cpm_command(fpi->cp_command, op);
}

static int do_pd_setup(struct fs_enet_private *fep)
{
        struct platform_device *ofdev = to_platform_device(fep->dev);
        struct fs_platform_info *fpi = fep->fpi;
        int ret = -EINVAL;

        fep->interrupt = irq_of_parse_and_map(ofdev->dev.of_node, 0);
        if (!fep->interrupt)
                goto out;

        fep->fcc.fccp = of_iomap(ofdev->dev.of_node, 0);
        if (!fep->fcc.fccp)
                goto out;

        fep->fcc.ep = of_iomap(ofdev->dev.of_node, 1);
        if (!fep->fcc.ep)
                goto out_fccp;

        fep->fcc.fcccp = of_iomap(ofdev->dev.of_node, 2);
        if (!fep->fcc.fcccp)
                goto out_ep;

        fep->fcc.mem = (void __iomem *)cpm2_immr;
        fpi->dpram_offset = cpm_muram_alloc(128, 32);
        if (IS_ERR_VALUE(fpi->dpram_offset)) {
                ret = fpi->dpram_offset;
                goto out_fcccp;
        }

        return 0;

out_fcccp:
        iounmap(fep->fcc.fcccp);
out_ep:
        iounmap(fep->fcc.ep);
out_fccp:
        iounmap(fep->fcc.fccp);
out:
        return ret;
}

#define FCC_NAPI_EVENT_MSK      (FCC_ENET_RXF | FCC_ENET_RXB | FCC_ENET_TXB)
#define FCC_EVENT               (FCC_ENET_RXF | FCC_ENET_TXB)
#define FCC_ERR_EVENT_MSK       (FCC_ENET_TXE)

static int setup_data(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);

        if (do_pd_setup(fep) != 0)
                return -EINVAL;

        fep->ev_napi = FCC_NAPI_EVENT_MSK;
        fep->ev = FCC_EVENT;
        fep->ev_err = FCC_ERR_EVENT_MSK;

        return 0;
}

static int allocate_bd(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        const struct fs_platform_info *fpi = fep->fpi;

        fep->ring_base = (void __iomem __force *)dma_alloc_coherent(fep->dev,
                                            (fpi->tx_ring + fpi->rx_ring) *
                                            sizeof(cbd_t), &fep->ring_mem_addr,
                                            GFP_KERNEL);
        if (fep->ring_base == NULL)
                return -ENOMEM;

        return 0;
}

static void free_bd(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        const struct fs_platform_info *fpi = fep->fpi;

        if (fep->ring_base)
                dma_free_coherent(fep->dev,
                        (fpi->tx_ring + fpi->rx_ring) * sizeof(cbd_t),
                        (void __force *)fep->ring_base, fep->ring_mem_addr);
}

static void cleanup_data(struct net_device *dev)
{
        /* nothing */
}

static void set_promiscuous_mode(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        fcc_t __iomem *fccp = fep->fcc.fccp;

        S32(fccp, fcc_fpsmr, FCC_PSMR_PRO);
}

static void set_multicast_start(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        fcc_enet_t __iomem *ep = fep->fcc.ep;

        W32(ep, fen_gaddrh, 0);
        W32(ep, fen_gaddrl, 0);
}

static void set_multicast_one(struct net_device *dev, const u8 *mac)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        fcc_enet_t __iomem *ep = fep->fcc.ep;
        u16 taddrh, taddrm, taddrl;

        taddrh = ((u16)mac[5] << 8) | mac[4];
        taddrm = ((u16)mac[3] << 8) | mac[2];
        taddrl = ((u16)mac[1] << 8) | mac[0];

        W16(ep, fen_taddrh, taddrh);
        W16(ep, fen_taddrm, taddrm);
        W16(ep, fen_taddrl, taddrl);
        fcc_cr_cmd(fep, CPM_CR_SET_GADDR);
}

static void set_multicast_finish(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        fcc_t __iomem *fccp = fep->fcc.fccp;
        fcc_enet_t __iomem *ep = fep->fcc.ep;

        /* clear promiscuous always */
        C32(fccp, fcc_fpsmr, FCC_PSMR_PRO);

        /* if all multi or too many multicasts; just enable all */
        if ((dev->flags & IFF_ALLMULTI) != 0 ||
            netdev_mc_count(dev) > FCC_MAX_MULTICAST_ADDRS) {

                W32(ep, fen_gaddrh, 0xffffffff);
                W32(ep, fen_gaddrl, 0xffffffff);
        }

        /* read back */
        fep->fcc.gaddrh = R32(ep, fen_gaddrh);
        fep->fcc.gaddrl = R32(ep, fen_gaddrl);
}

static void set_multicast_list(struct net_device *dev)
{
        struct netdev_hw_addr *ha;

        if ((dev->flags & IFF_PROMISC) == 0) {
                set_multicast_start(dev);
                netdev_for_each_mc_addr(ha, dev)
                        set_multicast_one(dev, ha->addr);
                set_multicast_finish(dev);
        } else
                set_promiscuous_mode(dev);
}

static void restart(struct net_device *dev, phy_interface_t interface,
                    int speed, int duplex)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        const struct fs_platform_info *fpi = fep->fpi;
        fcc_t __iomem *fccp = fep->fcc.fccp;
        fcc_c_t __iomem *fcccp = fep->fcc.fcccp;
        fcc_enet_t __iomem *ep = fep->fcc.ep;
        dma_addr_t rx_bd_base_phys, tx_bd_base_phys;
        u16 paddrh, paddrm, paddrl;
        const unsigned char *mac;
        int i;

        C32(fccp, fcc_gfmr, FCC_GFMR_ENR | FCC_GFMR_ENT);

        /* clear everything (slow & steady does it) */
        for (i = 0; i < sizeof(*ep); i++)
                out_8((u8 __iomem *)ep + i, 0);

        /* get physical address */
        rx_bd_base_phys = fep->ring_mem_addr;
        tx_bd_base_phys = rx_bd_base_phys + sizeof(cbd_t) * fpi->rx_ring;

        /* point to bds */
        W32(ep, fen_genfcc.fcc_rbase, rx_bd_base_phys);
        W32(ep, fen_genfcc.fcc_tbase, tx_bd_base_phys);

        /* Set maximum bytes per receive buffer.
         * It must be a multiple of 32.
         */
        W16(ep, fen_genfcc.fcc_mrblr, PKT_MAXBLR_SIZE);

        W32(ep, fen_genfcc.fcc_rstate, (CPMFCR_GBL | CPMFCR_EB) << 24);
        W32(ep, fen_genfcc.fcc_tstate, (CPMFCR_GBL | CPMFCR_EB) << 24);

        /* Allocate space in the reserved FCC area of DPRAM for the
         * internal buffers.  No one uses this space (yet), so we
         * can do this.  Later, we will add resource management for
         * this area.
         */

        W16(ep, fen_genfcc.fcc_riptr, fpi->dpram_offset);
        W16(ep, fen_genfcc.fcc_tiptr, fpi->dpram_offset + 32);

        W16(ep, fen_padptr, fpi->dpram_offset + 64);

        /* fill with special symbol...  */
        memset_io(fep->fcc.mem + fpi->dpram_offset + 64, 0x88, 32);

        W32(ep, fen_genfcc.fcc_rbptr, 0);
        W32(ep, fen_genfcc.fcc_tbptr, 0);
        W32(ep, fen_genfcc.fcc_rcrc, 0);
        W32(ep, fen_genfcc.fcc_tcrc, 0);
        W16(ep, fen_genfcc.fcc_res1, 0);
        W32(ep, fen_genfcc.fcc_res2, 0);

        /* no CAM */
        W32(ep, fen_camptr, 0);

        /* Set CRC preset and mask */
        W32(ep, fen_cmask, 0xdebb20e3);
        W32(ep, fen_cpres, 0xffffffff);

        W32(ep, fen_crcec, 0);          /* CRC Error counter       */
        W32(ep, fen_alec, 0);           /* alignment error counter */
        W32(ep, fen_disfc, 0);          /* discard frame counter   */
        W16(ep, fen_retlim, 15);        /* Retry limit threshold   */
        W16(ep, fen_pper, 0);           /* Normal persistence      */

        /* set group address */
        W32(ep, fen_gaddrh, fep->fcc.gaddrh);
        W32(ep, fen_gaddrl, fep->fcc.gaddrh);

        /* Clear hash filter tables */
        W32(ep, fen_iaddrh, 0);
        W32(ep, fen_iaddrl, 0);

        /* Clear the Out-of-sequence TxBD  */
        W16(ep, fen_tfcstat, 0);
        W16(ep, fen_tfclen, 0);
        W32(ep, fen_tfcptr, 0);

        W16(ep, fen_mflr, PKT_MAXBUF_SIZE);     /* maximum frame length register */
        W16(ep, fen_minflr, PKT_MINBUF_SIZE);   /* minimum frame length register */

        /* set address */
        mac = dev->dev_addr;
        paddrh = ((u16)mac[5] << 8) | mac[4];
        paddrm = ((u16)mac[3] << 8) | mac[2];
        paddrl = ((u16)mac[1] << 8) | mac[0];

        W16(ep, fen_paddrh, paddrh);
        W16(ep, fen_paddrm, paddrm);
        W16(ep, fen_paddrl, paddrl);

        W16(ep, fen_taddrh, 0);
        W16(ep, fen_taddrm, 0);
        W16(ep, fen_taddrl, 0);

        W16(ep, fen_maxd1, 1520);       /* maximum DMA1 length */
        W16(ep, fen_maxd2, 1520);       /* maximum DMA2 length */

        /* Clear stat counters, in case we ever enable RMON */
        W32(ep, fen_octc, 0);
        W32(ep, fen_colc, 0);
        W32(ep, fen_broc, 0);
        W32(ep, fen_mulc, 0);
        W32(ep, fen_uspc, 0);
        W32(ep, fen_frgc, 0);
        W32(ep, fen_ospc, 0);
        W32(ep, fen_jbrc, 0);
        W32(ep, fen_p64c, 0);
        W32(ep, fen_p65c, 0);
        W32(ep, fen_p128c, 0);
        W32(ep, fen_p256c, 0);
        W32(ep, fen_p512c, 0);
        W32(ep, fen_p1024c, 0);

        W16(ep, fen_rfthr, 0);  /* Suggested by manual */
        W16(ep, fen_rfcnt, 0);
        W16(ep, fen_cftype, 0);

        fs_init_bds(dev);

        /* adjust to speed (for RMII mode) */
        if (interface == PHY_INTERFACE_MODE_RMII) {
                if (speed == SPEED_100)
                        C8(fcccp, fcc_gfemr, 0x20);
                else
                        S8(fcccp, fcc_gfemr, 0x20);
        }

        fcc_cr_cmd(fep, CPM_CR_INIT_TRX);

        /* clear events */
        W16(fccp, fcc_fcce, 0xffff);

        /* Enable interrupts we wish to service */
        W16(fccp, fcc_fccm, FCC_ENET_TXE | FCC_ENET_RXF | FCC_ENET_TXB);

        /* Set GFMR to enable Ethernet operating mode */
        W32(fccp, fcc_gfmr, FCC_GFMR_TCI | FCC_GFMR_MODE_ENET);

        /* set sync/delimiters */
        W16(fccp, fcc_fdsr, 0xd555);

        W32(fccp, fcc_fpsmr, FCC_PSMR_ENCRC);

        if (interface == PHY_INTERFACE_MODE_RMII)
                S32(fccp, fcc_fpsmr, FCC_PSMR_RMII);

        /* adjust to duplex mode */
        if (duplex == DUPLEX_FULL)
                S32(fccp, fcc_fpsmr, FCC_PSMR_FDE | FCC_PSMR_LPB);
        else
                C32(fccp, fcc_fpsmr, FCC_PSMR_FDE | FCC_PSMR_LPB);

        /* Restore multicast and promiscuous settings */
        set_multicast_list(dev);

        S32(fccp, fcc_gfmr, FCC_GFMR_ENR | FCC_GFMR_ENT);
}

static void stop(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        fcc_t __iomem *fccp = fep->fcc.fccp;

        /* stop ethernet */
        C32(fccp, fcc_gfmr, FCC_GFMR_ENR | FCC_GFMR_ENT);

        /* clear events */
        W16(fccp, fcc_fcce, 0xffff);

        /* clear interrupt mask */
        W16(fccp, fcc_fccm, 0);

        fs_cleanup_bds(dev);
}

static void napi_clear_event_fs(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        fcc_t __iomem *fccp = fep->fcc.fccp;

        W16(fccp, fcc_fcce, FCC_NAPI_EVENT_MSK);
}

static void napi_enable_fs(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        fcc_t __iomem *fccp = fep->fcc.fccp;

        S16(fccp, fcc_fccm, FCC_NAPI_EVENT_MSK);
}

static void napi_disable_fs(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        fcc_t __iomem *fccp = fep->fcc.fccp;

        C16(fccp, fcc_fccm, FCC_NAPI_EVENT_MSK);
}

static void rx_bd_done(struct net_device *dev)
{
        /* nothing */
}

static void tx_kickstart(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        fcc_t __iomem *fccp = fep->fcc.fccp;

        S16(fccp, fcc_ftodr, 0x8000);
}

static u32 get_int_events(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        fcc_t __iomem *fccp = fep->fcc.fccp;

        return (u32)R16(fccp, fcc_fcce);
}

static void clear_int_events(struct net_device *dev, u32 int_events)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        fcc_t __iomem *fccp = fep->fcc.fccp;

        W16(fccp, fcc_fcce, int_events & 0xffff);
}

static void ev_error(struct net_device *dev, u32 int_events)
{
        struct fs_enet_private *fep = netdev_priv(dev);

        dev_warn(fep->dev, "FS_ENET ERROR(s) 0x%x\n", int_events);
}

static int get_regs(struct net_device *dev, void *p, int *sizep)
{
        struct fs_enet_private *fep = netdev_priv(dev);

        if (*sizep < sizeof(fcc_t) + sizeof(fcc_enet_t) + 1)
                return -EINVAL;

        memcpy_fromio(p, fep->fcc.fccp, sizeof(fcc_t));
        p = (char *)p + sizeof(fcc_t);

        memcpy_fromio(p, fep->fcc.ep, sizeof(fcc_enet_t));
        p = (char *)p + sizeof(fcc_enet_t);

        memcpy_fromio(p, fep->fcc.fcccp, 1);
        return 0;
}

static int get_regs_len(struct net_device *dev)
{
        return sizeof(fcc_t) + sizeof(fcc_enet_t) + 1;
}

/* Some transmit errors cause the transmitter to shut
 * down.  We now issue a restart transmit.
 * Also, to workaround 8260 device erratum CPM37, we must
 * disable and then re-enable the transmitterfollowing a
 * Late Collision, Underrun, or Retry Limit error.
 * In addition, tbptr may point beyond BDs beyond still marked
 * as ready due to internal pipelining, so we need to look back
 * through the BDs and adjust tbptr to point to the last BD
 * marked as ready.  This may result in some buffers being
 * retransmitted.
 */
static void tx_restart(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        fcc_t __iomem *fccp = fep->fcc.fccp;
        const struct fs_platform_info *fpi = fep->fpi;
        fcc_enet_t __iomem *ep = fep->fcc.ep;
        cbd_t __iomem *curr_tbptr;
        cbd_t __iomem *recheck_bd;
        cbd_t __iomem *prev_bd;
        cbd_t __iomem *last_tx_bd;

        last_tx_bd = fep->tx_bd_base + (fpi->tx_ring - 1);

        /* get the current bd held in TBPTR  and scan back from this point */
        recheck_bd = curr_tbptr = (cbd_t __iomem *)
                ((R32(ep, fen_genfcc.fcc_tbptr) - fep->ring_mem_addr) +
                fep->ring_base);

        prev_bd = (recheck_bd == fep->tx_bd_base) ? last_tx_bd : recheck_bd - 1;

        /* Move through the bds in reverse, look for the earliest buffer
         * that is not ready.  Adjust TBPTR to the following buffer */
        while ((CBDR_SC(prev_bd) & BD_ENET_TX_READY) != 0) {
                /* Go back one buffer */
                recheck_bd = prev_bd;

                /* update the previous buffer */
                prev_bd = (prev_bd == fep->tx_bd_base) ? last_tx_bd : prev_bd - 1;

                /* We should never see all bds marked as ready, check anyway */
                if (recheck_bd == curr_tbptr)
                        break;
        }
        /* Now update the TBPTR and dirty flag to the current buffer */
        W32(ep, fen_genfcc.fcc_tbptr,
                (uint)(((void __iomem *)recheck_bd - fep->ring_base) +
                fep->ring_mem_addr));
        fep->dirty_tx = recheck_bd;

        C32(fccp, fcc_gfmr, FCC_GFMR_ENT);
        udelay(10);
        S32(fccp, fcc_gfmr, FCC_GFMR_ENT);

        fcc_cr_cmd(fep, CPM_CR_RESTART_TX);
}

/*************************************************************************/

const struct fs_ops fs_fcc_ops = {
        .setup_data             = setup_data,
        .cleanup_data           = cleanup_data,
        .set_multicast_list     = set_multicast_list,
        .restart                = restart,
        .stop                   = stop,
        .napi_clear_event       = napi_clear_event_fs,
        .napi_enable            = napi_enable_fs,
        .napi_disable           = napi_disable_fs,
        .rx_bd_done             = rx_bd_done,
        .tx_kickstart           = tx_kickstart,
        .get_int_events         = get_int_events,
        .clear_int_events       = clear_int_events,
        .ev_error               = ev_error,
        .get_regs               = get_regs,
        .get_regs_len           = get_regs_len,
        .tx_restart             = tx_restart,
        .allocate_bd            = allocate_bd,
        .free_bd                = free_bd,
};