// SPDX-License-Identifier: GPL-2.0
/*
 * ip30-xtalk.c - Very basic Crosstalk (XIO) detection support.
 *   Copyright (C) 2004-2007 Stanislaw Skowronek <skylark@unaligned.org>
 *   Copyright (C) 2009 Johannes Dickgreber <tanzy@gmx.de>
 *   Copyright (C) 2007, 2014-2016 Joshua Kinard <linux@kumba.dev>
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/platform_data/sgi-w1.h>
#include <linux/platform_data/xtalk-bridge.h>

#include <asm/xtalk/xwidget.h>
#include <asm/pci/bridge.h>

#define IP30_SWIN_BASE(widget) \
                (0x0000000010000000 | (((unsigned long)(widget)) << 24))

#define IP30_RAW_SWIN_BASE(widget)      (IO_BASE + IP30_SWIN_BASE(widget))

#define IP30_SWIN_SIZE          (1 << 24)

#define IP30_WIDGET_XBOW        _AC(0x0, UL)    /* XBow is always 0 */
#define IP30_WIDGET_HEART       _AC(0x8, UL)    /* HEART is always 8 */
#define IP30_WIDGET_PCI_BASE    _AC(0xf, UL)    /* BaseIO PCI is always 15 */

#define XTALK_NODEV             0xffffffff

#define XBOW_REG_LINK_STAT_0    0x114
#define XBOW_REG_LINK_BLK_SIZE  0x40
#define XBOW_REG_LINK_ALIVE     0x80000000

#define HEART_INTR_ADDR         0x00000080

#define xtalk_read      __raw_readl

static void bridge_platform_create(int widget, int masterwid)
{
        struct xtalk_bridge_platform_data *bd;
        struct sgi_w1_platform_data *wd;
        struct platform_device *pdev_wd;
        struct platform_device *pdev_bd;
        struct resource w1_res;

        wd = kzalloc_obj(*wd);
        if (!wd) {
                pr_warn("xtalk:%x bridge create out of memory\n", widget);
                return;
        }

        snprintf(wd->dev_id, sizeof(wd->dev_id), "bridge-%012lx",
                 IP30_SWIN_BASE(widget));

        memset(&w1_res, 0, sizeof(w1_res));
        w1_res.start = IP30_SWIN_BASE(widget) +
                                offsetof(struct bridge_regs, b_nic);
        w1_res.end = w1_res.start + 3;
        w1_res.flags = IORESOURCE_MEM;

        pdev_wd = platform_device_alloc("sgi_w1", PLATFORM_DEVID_AUTO);
        if (!pdev_wd) {
                pr_warn("xtalk:%x bridge create out of memory\n", widget);
                goto err_kfree_wd;
        }
        if (platform_device_add_resources(pdev_wd, &w1_res, 1)) {
                pr_warn("xtalk:%x bridge failed to add platform resources.\n", widget);
                goto err_put_pdev_wd;
        }
        if (platform_device_add_data(pdev_wd, wd, sizeof(*wd))) {
                pr_warn("xtalk:%x bridge failed to add platform data.\n", widget);
                goto err_put_pdev_wd;
        }
        if (platform_device_add(pdev_wd)) {
                pr_warn("xtalk:%x bridge failed to add platform device.\n", widget);
                goto err_put_pdev_wd;
        }
        /* platform_device_add_data() duplicates the data */
        kfree(wd);

        bd = kzalloc_obj(*bd);
        if (!bd) {
                pr_warn("xtalk:%x bridge create out of memory\n", widget);
                goto err_unregister_pdev_wd;
        }
        pdev_bd = platform_device_alloc("xtalk-bridge", PLATFORM_DEVID_AUTO);
        if (!pdev_bd) {
                pr_warn("xtalk:%x bridge create out of memory\n", widget);
                goto err_kfree_bd;
        }

        bd->bridge_addr = IP30_RAW_SWIN_BASE(widget);
        bd->intr_addr   = HEART_INTR_ADDR;
        bd->nasid       = 0;
        bd->masterwid   = masterwid;

        bd->mem.name    = "Bridge PCI MEM";
        bd->mem.start   = IP30_SWIN_BASE(widget) + BRIDGE_DEVIO0;
        bd->mem.end     = IP30_SWIN_BASE(widget) + IP30_SWIN_SIZE - 1;
        bd->mem.flags   = IORESOURCE_MEM;
        bd->mem_offset  = IP30_SWIN_BASE(widget);

        bd->io.name     = "Bridge PCI IO";
        bd->io.start    = IP30_SWIN_BASE(widget) + BRIDGE_DEVIO0;
        bd->io.end      = IP30_SWIN_BASE(widget) + IP30_SWIN_SIZE - 1;
        bd->io.flags    = IORESOURCE_IO;
        bd->io_offset   = IP30_SWIN_BASE(widget);

        if (platform_device_add_data(pdev_bd, bd, sizeof(*bd))) {
                pr_warn("xtalk:%x bridge failed to add platform data.\n", widget);
                goto err_put_pdev_bd;
        }
        if (platform_device_add(pdev_bd)) {
                pr_warn("xtalk:%x bridge failed to add platform device.\n", widget);
                goto err_put_pdev_bd;
        }
        /* platform_device_add_data() duplicates the data */
        kfree(bd);
        pr_info("xtalk:%x bridge widget\n", widget);
        return;

err_put_pdev_bd:
        platform_device_put(pdev_bd);
err_kfree_bd:
        kfree(bd);
err_unregister_pdev_wd:
        platform_device_unregister(pdev_wd);
        return;
err_put_pdev_wd:
        platform_device_put(pdev_wd);
err_kfree_wd:
        kfree(wd);
        return;
}

static unsigned int __init xbow_widget_active(s8 wid)
{
        unsigned int link_stat;

        link_stat = xtalk_read((void *)(IP30_RAW_SWIN_BASE(IP30_WIDGET_XBOW) +
                                        XBOW_REG_LINK_STAT_0 +
                                        XBOW_REG_LINK_BLK_SIZE *
                                        (wid - 8)));

        return (link_stat & XBOW_REG_LINK_ALIVE) ? 1 : 0;
}

static void __init xtalk_init_widget(s8 wid, s8 masterwid)
{
        xwidget_part_num_t partnum;
        widgetreg_t widget_id;

        if (!xbow_widget_active(wid))
                return;

        widget_id = xtalk_read((void *)(IP30_RAW_SWIN_BASE(wid) + WIDGET_ID));

        partnum = XWIDGET_PART_NUM(widget_id);

        switch (partnum) {
        case BRIDGE_WIDGET_PART_NUM:
        case XBRIDGE_WIDGET_PART_NUM:
                bridge_platform_create(wid, masterwid);
                break;
        default:
                pr_info("xtalk:%x unknown widget (0x%x)\n", wid, partnum);
                break;
        }
}

static int __init ip30_xtalk_init(void)
{
        int i;

        /*
         * Walk widget IDs backwards so that BaseIO is probed first.  This
         * ensures that the BaseIO IOC3 is always detected as eth0.
         */
        for (i = IP30_WIDGET_PCI_BASE; i > IP30_WIDGET_HEART; i--)
                xtalk_init_widget(i, IP30_WIDGET_HEART);

        return 0;
}

arch_initcall(ip30_xtalk_init);