// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Support for ColdFire CPU based boards using a NS8390 Ethernet device.
 *
 *  Derived from the many other 8390 drivers.
 *
 *  (C) Copyright 2012,  Greg Ungerer <gerg@uclinux.org>
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/platform_device.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/jiffies.h>
#include <linux/io.h>
#include <asm/mcf8390.h>

static const char version[] =
        "mcf8390.c: (15-06-2012) Greg Ungerer <gerg@uclinux.org>";

#define NE_CMD          0x00
#define NE_DATAPORT     0x10    /* NatSemi-defined port window offset */
#define NE_RESET        0x1f    /* Issue a read to reset ,a write to clear */
#define NE_EN0_ISR      0x07
#define NE_EN0_DCFG     0x0e
#define NE_EN0_RSARLO   0x08
#define NE_EN0_RSARHI   0x09
#define NE_EN0_RCNTLO   0x0a
#define NE_EN0_RXCR     0x0c
#define NE_EN0_TXCR     0x0d
#define NE_EN0_RCNTHI   0x0b
#define NE_EN0_IMR      0x0f

#define NESM_START_PG   0x40    /* First page of TX buffer */
#define NESM_STOP_PG    0x80    /* Last page +1 of RX ring */

#ifdef NE2000_ODDOFFSET
/*
 * A lot of the ColdFire boards use a separate address region for odd offset
 * register addresses. The following functions convert and map as required.
 * Note that the data port accesses are treated a little differently, and
 * always accessed via the insX/outsX functions.
 */
static inline u32 NE_PTR(u32 addr)
{
        if (addr & 1)
                return addr - 1 + NE2000_ODDOFFSET;
        return addr;
}

static inline u32 NE_DATA_PTR(u32 addr)
{
        return addr;
}

void ei_outb(u32 val, u32 addr)
{
        NE2000_BYTE *rp;

        rp = (NE2000_BYTE *) NE_PTR(addr);
        *rp = RSWAP(val);
}

#define ei_inb  ei_inb
u8 ei_inb(u32 addr)
{
        NE2000_BYTE *rp, val;

        rp = (NE2000_BYTE *) NE_PTR(addr);
        val = *rp;
        return (u8) (RSWAP(val) & 0xff);
}

void ei_insb(u32 addr, void *vbuf, int len)
{
        NE2000_BYTE *rp, val;
        u8 *buf;

        buf = (u8 *) vbuf;
        rp = (NE2000_BYTE *) NE_DATA_PTR(addr);
        for (; (len > 0); len--) {
                val = *rp;
                *buf++ = RSWAP(val);
        }
}

void ei_insw(u32 addr, void *vbuf, int len)
{
        volatile u16 *rp;
        u16 w, *buf;

        buf = (u16 *) vbuf;
        rp = (volatile u16 *) NE_DATA_PTR(addr);
        for (; (len > 0); len--) {
                w = *rp;
                *buf++ = BSWAP(w);
        }
}

void ei_outsb(u32 addr, const void *vbuf, int len)
{
        NE2000_BYTE *rp, val;
        u8 *buf;

        buf = (u8 *) vbuf;
        rp = (NE2000_BYTE *) NE_DATA_PTR(addr);
        for (; (len > 0); len--) {
                val = *buf++;
                *rp = RSWAP(val);
        }
}

void ei_outsw(u32 addr, const void *vbuf, int len)
{
        volatile u16 *rp;
        u16 w, *buf;

        buf = (u16 *) vbuf;
        rp = (volatile u16 *) NE_DATA_PTR(addr);
        for (; (len > 0); len--) {
                w = *buf++;
                *rp = BSWAP(w);
        }
}

#else /* !NE2000_ODDOFFSET */

#define ei_inb          inb
#define ei_outb         outb
#define ei_insb         insb
#define ei_insw         insw
#define ei_outsb        outsb
#define ei_outsw        outsw

#endif /* !NE2000_ODDOFFSET */

#define ei_inb_p        ei_inb
#define ei_outb_p       ei_outb

#include "lib8390.c"

/*
 * Hard reset the card. This used to pause for the same period that a
 * 8390 reset command required, but that shouldn't be necessary.
 */
static void mcf8390_reset_8390(struct net_device *dev)
{
        unsigned long reset_start_time = jiffies;
        u32 addr = dev->base_addr;
        struct ei_device *ei_local = netdev_priv(dev);

        netif_dbg(ei_local, hw, dev, "resetting the 8390 t=%ld...\n", jiffies);

        ei_outb(ei_inb(addr + NE_RESET), addr + NE_RESET);

        ei_status.txing = 0;
        ei_status.dmaing = 0;

        /* This check _should_not_ be necessary, omit eventually. */
        while ((ei_inb(addr + NE_EN0_ISR) & ENISR_RESET) == 0) {
                if (time_after(jiffies, reset_start_time + 2 * HZ / 100)) {
                        netdev_warn(dev, "%s: did not complete\n", __func__);
                        break;
                }
        }

        ei_outb(ENISR_RESET, addr + NE_EN0_ISR);
}

/*
 * This *shouldn't* happen.
 * If it does, it's the last thing you'll see
 */
static void mcf8390_dmaing_err(const char *func, struct net_device *dev,
                               struct ei_device *ei_local)
{
        netdev_err(dev, "%s: DMAing conflict [DMAstat:%d][irqlock:%d]\n",
                func, ei_local->dmaing, ei_local->irqlock);
}

/*
 * Grab the 8390 specific header. Similar to the block_input routine, but
 * we don't need to be concerned with ring wrap as the header will be at
 * the start of a page, so we optimize accordingly.
 */
static void mcf8390_get_8390_hdr(struct net_device *dev,
                                 struct e8390_pkt_hdr *hdr, int ring_page)
{
        struct ei_device *ei_local = netdev_priv(dev);
        u32 addr = dev->base_addr;

        if (ei_local->dmaing) {
                mcf8390_dmaing_err(__func__, dev, ei_local);
                return;
        }

        ei_local->dmaing |= 0x01;
        ei_outb(E8390_NODMA + E8390_PAGE0 + E8390_START, addr + NE_CMD);
        ei_outb(ENISR_RDC, addr + NE_EN0_ISR);
        ei_outb(sizeof(struct e8390_pkt_hdr), addr + NE_EN0_RCNTLO);
        ei_outb(0, addr + NE_EN0_RCNTHI);
        ei_outb(0, addr + NE_EN0_RSARLO);               /* On page boundary */
        ei_outb(ring_page, addr + NE_EN0_RSARHI);
        ei_outb(E8390_RREAD + E8390_START, addr + NE_CMD);

        ei_insw(addr + NE_DATAPORT, hdr, sizeof(struct e8390_pkt_hdr) >> 1);

        outb(ENISR_RDC, addr + NE_EN0_ISR);     /* Ack intr */
        ei_local->dmaing &= ~0x01;

        hdr->count = cpu_to_le16(hdr->count);
}

/*
 * Block input and output, similar to the Crynwr packet driver.
 * If you are porting to a new ethercard, look at the packet driver source
 * for hints. The NEx000 doesn't share the on-board packet memory --
 * you have to put the packet out through the "remote DMA" dataport
 * using z_writeb.
 */
static void mcf8390_block_input(struct net_device *dev, int count,
                                struct sk_buff *skb, int ring_offset)
{
        struct ei_device *ei_local = netdev_priv(dev);
        u32 addr = dev->base_addr;
        char *buf = skb->data;

        if (ei_local->dmaing) {
                mcf8390_dmaing_err(__func__, dev, ei_local);
                return;
        }

        ei_local->dmaing |= 0x01;
        ei_outb(E8390_NODMA + E8390_PAGE0 + E8390_START, addr + NE_CMD);
        ei_outb(ENISR_RDC, addr + NE_EN0_ISR);
        ei_outb(count & 0xff, addr + NE_EN0_RCNTLO);
        ei_outb(count >> 8, addr + NE_EN0_RCNTHI);
        ei_outb(ring_offset & 0xff, addr + NE_EN0_RSARLO);
        ei_outb(ring_offset >> 8, addr + NE_EN0_RSARHI);
        ei_outb(E8390_RREAD + E8390_START, addr + NE_CMD);

        ei_insw(addr + NE_DATAPORT, buf, count >> 1);
        if (count & 1)
                buf[count - 1] = ei_inb(addr + NE_DATAPORT);

        ei_outb(ENISR_RDC, addr + NE_EN0_ISR);  /* Ack intr */
        ei_local->dmaing &= ~0x01;
}

static void mcf8390_block_output(struct net_device *dev, int count,
                                 const unsigned char *buf,
                                 const int start_page)
{
        struct ei_device *ei_local = netdev_priv(dev);
        u32 addr = dev->base_addr;
        unsigned long dma_start;

        /* Make sure we transfer all bytes if 16bit IO writes */
        if (count & 0x1)
                count++;

        if (ei_local->dmaing) {
                mcf8390_dmaing_err(__func__, dev, ei_local);
                return;
        }

        ei_local->dmaing |= 0x01;
        /* We should already be in page 0, but to be safe... */
        ei_outb(E8390_PAGE0 + E8390_START + E8390_NODMA, addr + NE_CMD);

        ei_outb(ENISR_RDC, addr + NE_EN0_ISR);

        /* Now the normal output. */
        ei_outb(count & 0xff, addr + NE_EN0_RCNTLO);
        ei_outb(count >> 8, addr + NE_EN0_RCNTHI);
        ei_outb(0x00, addr + NE_EN0_RSARLO);
        ei_outb(start_page, addr + NE_EN0_RSARHI);
        ei_outb(E8390_RWRITE + E8390_START, addr + NE_CMD);

        ei_outsw(addr + NE_DATAPORT, buf, count >> 1);

        dma_start = jiffies;
        while ((ei_inb(addr + NE_EN0_ISR) & ENISR_RDC) == 0) {
                if (time_after(jiffies, dma_start + 2 * HZ / 100)) { /* 20ms */
                        netdev_warn(dev, "timeout waiting for Tx RDC\n");
                        mcf8390_reset_8390(dev);
                        __NS8390_init(dev, 1);
                        break;
                }
        }

        ei_outb(ENISR_RDC, addr + NE_EN0_ISR);  /* Ack intr */
        ei_local->dmaing &= ~0x01;
}

static const struct net_device_ops mcf8390_netdev_ops = {
        .ndo_open               = __ei_open,
        .ndo_stop               = __ei_close,
        .ndo_start_xmit         = __ei_start_xmit,
        .ndo_tx_timeout         = __ei_tx_timeout,
        .ndo_get_stats          = __ei_get_stats,
        .ndo_set_rx_mode        = __ei_set_multicast_list,
        .ndo_validate_addr      = eth_validate_addr,
        .ndo_set_mac_address    = eth_mac_addr,
#ifdef CONFIG_NET_POLL_CONTROLLER
        .ndo_poll_controller    = __ei_poll,
#endif
};

static int mcf8390_init(struct net_device *dev)
{
        static u32 offsets[] = {
                0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
                0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
        };
        struct ei_device *ei_local = netdev_priv(dev);
        unsigned char SA_prom[32];
        u32 addr = dev->base_addr;
        int start_page, stop_page;
        int i, ret;

        mcf8390_reset_8390(dev);

        /*
         * Read the 16 bytes of station address PROM.
         * We must first initialize registers,
         * similar to NS8390_init(eifdev, 0).
         * We can't reliably read the SAPROM address without this.
         * (I learned the hard way!).
         */
        {
                static const struct {
                        u32 value;
                        u32 offset;
                } program_seq[] = {
                        {E8390_NODMA + E8390_PAGE0 + E8390_STOP, NE_CMD},
                                                /* Select page 0 */
                        {0x48,  NE_EN0_DCFG},   /* 0x48: Set byte-wide access */
                        {0x00,  NE_EN0_RCNTLO}, /* Clear the count regs */
                        {0x00,  NE_EN0_RCNTHI},
                        {0x00,  NE_EN0_IMR},    /* Mask completion irq */
                        {0xFF,  NE_EN0_ISR},
                        {E8390_RXOFF, NE_EN0_RXCR}, /* 0x20 Set to monitor */
                        {E8390_TXOFF, NE_EN0_TXCR}, /* 0x02 and loopback mode */
                        {32,    NE_EN0_RCNTLO},
                        {0x00,  NE_EN0_RCNTHI},
                        {0x00,  NE_EN0_RSARLO}, /* DMA starting at 0x0000 */
                        {0x00,  NE_EN0_RSARHI},
                        {E8390_RREAD + E8390_START, NE_CMD},
                };
                for (i = 0; i < ARRAY_SIZE(program_seq); i++) {
                        ei_outb(program_seq[i].value,
                                 addr + program_seq[i].offset);
                }
        }

        for (i = 0; i < 16; i++) {
                SA_prom[i] = ei_inb(addr + NE_DATAPORT);
                ei_inb(addr + NE_DATAPORT);
        }

        /* We must set the 8390 for word mode. */
        ei_outb(0x49, addr + NE_EN0_DCFG);
        start_page = NESM_START_PG;
        stop_page = NESM_STOP_PG;

        /* Install the Interrupt handler */
        ret = request_irq(dev->irq, __ei_interrupt, 0, dev->name, dev);
        if (ret)
                return ret;

        eth_hw_addr_set(dev, SA_prom);

        netdev_dbg(dev, "Found ethernet address: %pM\n", dev->dev_addr);

        ei_local->name = "mcf8390";
        ei_local->tx_start_page = start_page;
        ei_local->stop_page = stop_page;
        ei_local->word16 = 1;
        ei_local->rx_start_page = start_page + TX_PAGES;
        ei_local->reset_8390 = mcf8390_reset_8390;
        ei_local->block_input = mcf8390_block_input;
        ei_local->block_output = mcf8390_block_output;
        ei_local->get_8390_hdr = mcf8390_get_8390_hdr;
        ei_local->reg_offset = offsets;

        dev->netdev_ops = &mcf8390_netdev_ops;
        __NS8390_init(dev, 0);
        ret = register_netdev(dev);
        if (ret) {
                free_irq(dev->irq, dev);
                return ret;
        }

        netdev_info(dev, "addr=0x%08x irq=%d, Ethernet Address %pM\n",
                addr, dev->irq, dev->dev_addr);
        return 0;
}

static int mcf8390_probe(struct platform_device *pdev)
{
        struct net_device *dev;
        struct resource *mem;
        resource_size_t msize;
        int ret, irq;

        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                return -ENXIO;

        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (mem == NULL) {
                dev_err(&pdev->dev, "no memory address specified?\n");
                return -ENXIO;
        }
        msize = resource_size(mem);
        if (!request_mem_region(mem->start, msize, pdev->name))
                return -EBUSY;

        dev = ____alloc_ei_netdev(0);
        if (dev == NULL) {
                release_mem_region(mem->start, msize);
                return -ENOMEM;
        }

        SET_NETDEV_DEV(dev, &pdev->dev);
        platform_set_drvdata(pdev, dev);

        dev->irq = irq;
        dev->base_addr = mem->start;

        ret = mcf8390_init(dev);
        if (ret) {
                release_mem_region(mem->start, msize);
                free_netdev(dev);
                return ret;
        }
        return 0;
}

static void mcf8390_remove(struct platform_device *pdev)
{
        struct net_device *dev = platform_get_drvdata(pdev);
        struct resource *mem;

        unregister_netdev(dev);
        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        release_mem_region(mem->start, resource_size(mem));
        free_netdev(dev);
}

static struct platform_driver mcf8390_drv = {
        .driver = {
                .name   = "mcf8390",
        },
        .probe          = mcf8390_probe,
        .remove         = mcf8390_remove,
};

module_platform_driver(mcf8390_drv);

MODULE_DESCRIPTION("MCF8390 ColdFire NS8390 driver");
MODULE_AUTHOR("Greg Ungerer <gerg@uclinux.org>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:mcf8390");