/*
 * Ethernet on Serial Communications Controller (SCC) driver for Motorola MPC8xx and MPC82xx.
 *
 * Copyright (c) 2003 Intracom S.A.
 *  by Pantelis Antoniou <panto@intracom.gr>
 *
 * 2005 (c) MontaVista Software, Inc.
 * Vitaly Bordug <vbordug@ru.mvista.com>
 *
 * This file is licensed under the terms of the GNU General Public License
 * version 2. This program is licensed "as is" without any warranty of any
 * kind, whether express or implied.
 */

#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/init.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/mii.h>
#include <linux/ethtool.h>
#include <linux/bitops.h>
#include <linux/fs.h>
#include <linux/platform_device.h>
#include <linux/of_platform.h>

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

#ifdef CONFIG_8xx
#include <asm/8xx_immap.h>
#include <asm/pgtable.h>
#include <asm/mpc8xx.h>
#include <asm/cpm1.h>
#endif

#include "fs_enet.h"

/*************************************************/
#if defined(CONFIG_CPM1)
/* for a 8xx __raw_xxx's are sufficient */
#define __fs_out32(addr, x)     __raw_writel(x, addr)
#define __fs_out16(addr, x)     __raw_writew(x, addr)
#define __fs_out8(addr, x)      __raw_writeb(x, addr)
#define __fs_in32(addr) __raw_readl(addr)
#define __fs_in16(addr) __raw_readw(addr)
#define __fs_in8(addr)  __raw_readb(addr)
#else
/* for others play it safe */
#define __fs_out32(addr, x)     out_be32(addr, x)
#define __fs_out16(addr, x)     out_be16(addr, x)
#define __fs_in32(addr) in_be32(addr)
#define __fs_in16(addr) in_be16(addr)
#define __fs_out8(addr, x)      out_8(addr, x)
#define __fs_in8(addr)  in_8(addr)
#endif

/* write, read, set bits, clear bits */
#define W32(_p, _m, _v) __fs_out32(&(_p)->_m, (_v))
#define R32(_p, _m)     __fs_in32(&(_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) __fs_out16(&(_p)->_m, (_v))
#define R16(_p, _m)     __fs_in16(&(_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)  __fs_out8(&(_p)->_m, (_v))
#define R8(_p, _m)      __fs_in8(&(_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 SCC_MAX_MULTICAST_ADDRS 64

/*
 * Delay to wait for SCC reset command to complete (in us)
 */
#define SCC_RESET_DELAY         50

static inline int scc_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);

        fep->interrupt = of_irq_to_resource(ofdev->dev.of_node, 0, NULL);
        if (fep->interrupt == NO_IRQ)
                return -EINVAL;

        fep->scc.sccp = of_iomap(ofdev->dev.of_node, 0);
        if (!fep->scc.sccp)
                return -EINVAL;

        fep->scc.ep = of_iomap(ofdev->dev.of_node, 1);
        if (!fep->scc.ep) {
                iounmap(fep->scc.sccp);
                return -EINVAL;
        }

        return 0;
}

#define SCC_NAPI_RX_EVENT_MSK   (SCCE_ENET_RXF | SCCE_ENET_RXB)
#define SCC_RX_EVENT            (SCCE_ENET_RXF)
#define SCC_TX_EVENT            (SCCE_ENET_TXB)
#define SCC_ERR_EVENT_MSK       (SCCE_ENET_TXE | SCCE_ENET_BSY)

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

        do_pd_setup(fep);

        fep->scc.hthi = 0;
        fep->scc.htlo = 0;

        fep->ev_napi_rx = SCC_NAPI_RX_EVENT_MSK;
        fep->ev_rx = SCC_RX_EVENT;
        fep->ev_tx = SCC_TX_EVENT | SCCE_ENET_TXE;
        fep->ev_err = SCC_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_mem_addr = cpm_dpalloc((fpi->tx_ring + fpi->rx_ring) *
                                         sizeof(cbd_t), 8);
        if (IS_ERR_VALUE(fep->ring_mem_addr))
                return -ENOMEM;

        fep->ring_base = (void __iomem __force*)
                cpm_dpram_addr(fep->ring_mem_addr);

        return 0;
}

static void free_bd(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);

        if (fep->ring_base)
                cpm_dpfree(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);
        scc_t __iomem *sccp = fep->scc.sccp;

        S16(sccp, scc_psmr, SCC_PSMR_PRO);
}

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

        W16(ep, sen_gaddr1, 0);
        W16(ep, sen_gaddr2, 0);
        W16(ep, sen_gaddr3, 0);
        W16(ep, sen_gaddr4, 0);
}

static void set_multicast_one(struct net_device *dev, const u8 * mac)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        scc_enet_t __iomem *ep = fep->scc.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, sen_taddrh, taddrh);
        W16(ep, sen_taddrm, taddrm);
        W16(ep, sen_taddrl, taddrl);
        scc_cr_cmd(fep, CPM_CR_SET_GADDR);
}

static void set_multicast_finish(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        scc_t __iomem *sccp = fep->scc.sccp;
        scc_enet_t __iomem *ep = fep->scc.ep;

        /* clear promiscuous always */
        C16(sccp, scc_psmr, SCC_PSMR_PRO);

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

                W16(ep, sen_gaddr1, 0xffff);
                W16(ep, sen_gaddr2, 0xffff);
                W16(ep, sen_gaddr3, 0xffff);
                W16(ep, sen_gaddr4, 0xffff);
        }
}

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);
}

/*
 * This function is called to start or restart the FEC during a link
 * change.  This only happens when switching between half and full
 * duplex.
 */
static void restart(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        scc_t __iomem *sccp = fep->scc.sccp;
        scc_enet_t __iomem *ep = fep->scc.ep;
        const struct fs_platform_info *fpi = fep->fpi;
        u16 paddrh, paddrm, paddrl;
        const unsigned char *mac;
        int i;

        C32(sccp, scc_gsmrl, SCC_GSMRL_ENR | SCC_GSMRL_ENT);

        /* clear everything (slow & steady does it) */
        for (i = 0; i < sizeof(*ep); i++)
                __fs_out8((u8 __iomem *)ep + i, 0);

        /* point to bds */
        W16(ep, sen_genscc.scc_rbase, fep->ring_mem_addr);
        W16(ep, sen_genscc.scc_tbase,
            fep->ring_mem_addr + sizeof(cbd_t) * fpi->rx_ring);

        /* Initialize function code registers for big-endian.
         */
#ifndef CONFIG_NOT_COHERENT_CACHE
        W8(ep, sen_genscc.scc_rfcr, SCC_EB | SCC_GBL);
        W8(ep, sen_genscc.scc_tfcr, SCC_EB | SCC_GBL);
#else
        W8(ep, sen_genscc.scc_rfcr, SCC_EB);
        W8(ep, sen_genscc.scc_tfcr, SCC_EB);
#endif

        /* Set maximum bytes per receive buffer.
         * This appears to be an Ethernet frame size, not the buffer
         * fragment size.  It must be a multiple of four.
         */
        W16(ep, sen_genscc.scc_mrblr, 0x5f0);

        /* Set CRC preset and mask.
         */
        W32(ep, sen_cpres, 0xffffffff);
        W32(ep, sen_cmask, 0xdebb20e3);

        W32(ep, sen_crcec, 0);  /* CRC Error counter */
        W32(ep, sen_alec, 0);   /* alignment error counter */
        W32(ep, sen_disfc, 0);  /* discard frame counter */

        W16(ep, sen_pads, 0x8888);      /* Tx short frame pad character */
        W16(ep, sen_retlim, 15);        /* Retry limit threshold */

        W16(ep, sen_maxflr, 0x5ee);     /* maximum frame length register */

        W16(ep, sen_minflr, PKT_MINBUF_SIZE);   /* minimum frame length register */

        W16(ep, sen_maxd1, 0x000005f0); /* maximum DMA1 length */
        W16(ep, sen_maxd2, 0x000005f0); /* maximum DMA2 length */

        /* Clear hash tables.
         */
        W16(ep, sen_gaddr1, 0);
        W16(ep, sen_gaddr2, 0);
        W16(ep, sen_gaddr3, 0);
        W16(ep, sen_gaddr4, 0);
        W16(ep, sen_iaddr1, 0);
        W16(ep, sen_iaddr2, 0);
        W16(ep, sen_iaddr3, 0);
        W16(ep, sen_iaddr4, 0);

        /* 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, sen_paddrh, paddrh);
        W16(ep, sen_paddrm, paddrm);
        W16(ep, sen_paddrl, paddrl);

        W16(ep, sen_pper, 0);
        W16(ep, sen_taddrl, 0);
        W16(ep, sen_taddrm, 0);
        W16(ep, sen_taddrh, 0);

        fs_init_bds(dev);

        scc_cr_cmd(fep, CPM_CR_INIT_TRX);

        W16(sccp, scc_scce, 0xffff);

        /* Enable interrupts we wish to service.
         */
        W16(sccp, scc_sccm, SCCE_ENET_TXE | SCCE_ENET_RXF | SCCE_ENET_TXB);

        /* Set GSMR_H to enable all normal operating modes.
         * Set GSMR_L to enable Ethernet to MC68160.
         */
        W32(sccp, scc_gsmrh, 0);
        W32(sccp, scc_gsmrl,
            SCC_GSMRL_TCI | SCC_GSMRL_TPL_48 | SCC_GSMRL_TPP_10 |
            SCC_GSMRL_MODE_ENET);

        /* Set sync/delimiters.
         */
        W16(sccp, scc_dsr, 0xd555);

        /* Set processing mode.  Use Ethernet CRC, catch broadcast, and
         * start frame search 22 bit times after RENA.
         */
        W16(sccp, scc_psmr, SCC_PSMR_ENCRC | SCC_PSMR_NIB22);

        /* Set full duplex mode if needed */
        if (fep->phydev->duplex)
                S16(sccp, scc_psmr, SCC_PSMR_LPB | SCC_PSMR_FDE);

        S32(sccp, scc_gsmrl, SCC_GSMRL_ENR | SCC_GSMRL_ENT);
}

static void stop(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        scc_t __iomem *sccp = fep->scc.sccp;
        int i;

        for (i = 0; (R16(sccp, scc_sccm) == 0) && i < SCC_RESET_DELAY; i++)
                udelay(1);

        if (i == SCC_RESET_DELAY)
                dev_warn(fep->dev, "SCC timeout on graceful transmit stop\n");

        W16(sccp, scc_sccm, 0);
        C32(sccp, scc_gsmrl, SCC_GSMRL_ENR | SCC_GSMRL_ENT);

        fs_cleanup_bds(dev);
}

static void napi_clear_rx_event(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        scc_t __iomem *sccp = fep->scc.sccp;

        W16(sccp, scc_scce, SCC_NAPI_RX_EVENT_MSK);
}

static void napi_enable_rx(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        scc_t __iomem *sccp = fep->scc.sccp;

        S16(sccp, scc_sccm, SCC_NAPI_RX_EVENT_MSK);
}

static void napi_disable_rx(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        scc_t __iomem *sccp = fep->scc.sccp;

        C16(sccp, scc_sccm, SCC_NAPI_RX_EVENT_MSK);
}

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

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

static u32 get_int_events(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        scc_t __iomem *sccp = fep->scc.sccp;

        return (u32) R16(sccp, scc_scce);
}

static void clear_int_events(struct net_device *dev, u32 int_events)
{
        struct fs_enet_private *fep = netdev_priv(dev);
        scc_t __iomem *sccp = fep->scc.sccp;

        W16(sccp, scc_scce, 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, "SCC 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(scc_t) + sizeof(scc_enet_t __iomem *))
                return -EINVAL;

        memcpy_fromio(p, fep->scc.sccp, sizeof(scc_t));
        p = (char *)p + sizeof(scc_t);

        memcpy_fromio(p, fep->scc.ep, sizeof(scc_enet_t __iomem *));

        return 0;
}

static int get_regs_len(struct net_device *dev)
{
        return sizeof(scc_t) + sizeof(scc_enet_t __iomem *);
}

static void tx_restart(struct net_device *dev)
{
        struct fs_enet_private *fep = netdev_priv(dev);

        scc_cr_cmd(fep, CPM_CR_RESTART_TX);
}



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

const struct fs_ops fs_scc_ops = {
        .setup_data             = setup_data,
        .cleanup_data           = cleanup_data,
        .set_multicast_list     = set_multicast_list,
        .restart                = restart,
        .stop                   = stop,
        .napi_clear_rx_event    = napi_clear_rx_event,
        .napi_enable_rx         = napi_enable_rx,
        .napi_disable_rx        = napi_disable_rx,
        .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,
};