// SPDX-License-Identifier: GPL-2.0-only
/*
 *      HP300 Topcat framebuffer support (derived from macfb of all things)
 *      Phil Blundell <philb@gnu.org> 1998
 *      DIO-II, colour map and Catseye support by
 *      Kars de Jong <jongk@linux-m68k.org>, May 2004.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/fb.h>
#include <linux/dio.h>

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

static struct fb_info fb_info = {
        .fix = {
                .id             = "HP300 ",
                .type           = FB_TYPE_PACKED_PIXELS,
                .visual         = FB_VISUAL_PSEUDOCOLOR,
                .accel          = FB_ACCEL_NONE,
        }
};

static unsigned long fb_regs;
static unsigned char fb_bitmask;

#define TC_NBLANK       0x4080
#define TC_WEN          0x4088
#define TC_REN          0x408c
#define TC_FBEN         0x4090
#define TC_PRR          0x40ea

/* These defines match the X window system */
#define RR_CLEAR        0x0
#define RR_COPY         0x3
#define RR_NOOP         0x5
#define RR_XOR          0x6
#define RR_INVERT       0xa
#define RR_COPYINVERTED 0xc
#define RR_SET          0xf

/* blitter regs */
#define BUSY            0x4044
#define WMRR            0x40ef
#define SOURCE_X        0x40f2
#define SOURCE_Y        0x40f6
#define DEST_X          0x40fa
#define DEST_Y          0x40fe
#define WHEIGHT         0x4106
#define WWIDTH          0x4102
#define WMOVE           0x409c

static struct fb_var_screeninfo hpfb_defined = {
        .red            = {
                .length = 8,
        },
        .green          = {
                .length = 8,
        },
        .blue           = {
                .length = 8,
        },
        .activate       = FB_ACTIVATE_NOW,
        .height         = -1,
        .width          = -1,
        .vmode          = FB_VMODE_NONINTERLACED,
};

static int hpfb_setcolreg(unsigned regno, unsigned red, unsigned green,
                          unsigned blue, unsigned transp,
                          struct fb_info *info)
{
        /* use MSBs */
        unsigned char _red  =red>>8;
        unsigned char _green=green>>8;
        unsigned char _blue =blue>>8;
        unsigned char _regno=regno;

        /*
         *  Set a single color register. The values supplied are
         *  already rounded down to the hardware's capabilities
         *  (according to the entries in the `var' structure). Return
         *  != 0 for invalid regno.
         */

        if (regno >= info->cmap.len)
                return 1;

        while (in_be16(fb_regs + 0x6002) & 0x4) udelay(1);

        out_be16(fb_regs + 0x60ba, 0xff);

        out_be16(fb_regs + 0x60b2, _red);
        out_be16(fb_regs + 0x60b4, _green);
        out_be16(fb_regs + 0x60b6, _blue);
        out_be16(fb_regs + 0x60b8, ~_regno);
        out_be16(fb_regs + 0x60f0, 0xff);

        udelay(100);

        while (in_be16(fb_regs + 0x6002) & 0x4) udelay(1);
        out_be16(fb_regs + 0x60b2, 0);
        out_be16(fb_regs + 0x60b4, 0);
        out_be16(fb_regs + 0x60b6, 0);
        out_be16(fb_regs + 0x60b8, 0);

        return 0;
}

/* 0 unblank, 1 blank, 2 no vsync, 3 no hsync, 4 off */

static int hpfb_blank(int blank, struct fb_info *info)
{
        out_8(fb_regs + TC_NBLANK, (blank ? 0x00 : fb_bitmask));

        return 0;
}

static void topcat_blit(int x0, int y0, int x1, int y1, int w, int h, int rr)
{
        if (rr >= 0) {
                while (in_8(fb_regs + BUSY) & fb_bitmask)
                        ;
        }
        out_8(fb_regs + TC_FBEN, fb_bitmask);
        if (rr >= 0) {
                out_8(fb_regs + TC_WEN, fb_bitmask);
                out_8(fb_regs + WMRR, rr);
        }
        out_be16(fb_regs + SOURCE_X, x0);
        out_be16(fb_regs + SOURCE_Y, y0);
        out_be16(fb_regs + DEST_X, x1);
        out_be16(fb_regs + DEST_Y, y1);
        out_be16(fb_regs + WWIDTH, w);
        out_be16(fb_regs + WHEIGHT, h);
        out_8(fb_regs + WMOVE, fb_bitmask);
}

static void hpfb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
{
        topcat_blit(area->sx, area->sy, area->dx, area->dy, area->width, area->height, RR_COPY);
}

static void hpfb_fillrect(struct fb_info *p, const struct fb_fillrect *region)
{
        u8 clr;

        clr = region->color & 0xff;

        while (in_8(fb_regs + BUSY) & fb_bitmask)
                ;

        /* Foreground */
        out_8(fb_regs + TC_WEN, fb_bitmask & clr);
        out_8(fb_regs + WMRR, (region->rop == ROP_COPY ? RR_SET : RR_INVERT));

        /* Background */
        out_8(fb_regs + TC_WEN, fb_bitmask & ~clr);
        out_8(fb_regs + WMRR, (region->rop == ROP_COPY ? RR_CLEAR : RR_NOOP));

        topcat_blit(region->dx, region->dy, region->dx, region->dy, region->width, region->height, -1);
}

static int hpfb_sync(struct fb_info *info)
{
        /*
         * Since we also access the framebuffer directly, we have to wait
         * until the block mover is finished
         */
        while (in_8(fb_regs + BUSY) & fb_bitmask)
                ;

        out_8(fb_regs + TC_WEN, fb_bitmask);
        out_8(fb_regs + TC_PRR, RR_COPY);
        out_8(fb_regs + TC_FBEN, fb_bitmask);

        return 0;
}

static const struct fb_ops hpfb_ops = {
        .owner          = THIS_MODULE,
        __FB_DEFAULT_IOMEM_OPS_RDWR,
        .fb_setcolreg   = hpfb_setcolreg,
        .fb_blank       = hpfb_blank,
        .fb_fillrect    = hpfb_fillrect,
        .fb_copyarea    = hpfb_copyarea,
        .fb_imageblit   = cfb_imageblit,
        .fb_sync        = hpfb_sync,
        __FB_DEFAULT_IOMEM_OPS_MMAP,
};

/* Common to all HP framebuffers */
#define HPFB_FBWMSB     0x05    /* Frame buffer width           */
#define HPFB_FBWLSB     0x07
#define HPFB_FBHMSB     0x09    /* Frame buffer height          */
#define HPFB_FBHLSB     0x0b
#define HPFB_DWMSB      0x0d    /* Display width                */
#define HPFB_DWLSB      0x0f
#define HPFB_DHMSB      0x11    /* Display height               */
#define HPFB_DHLSB      0x13
#define HPFB_NUMPLANES  0x5b    /* Number of colour planes      */
#define HPFB_FBOMSB     0x5d    /* Frame buffer offset          */
#define HPFB_FBOLSB     0x5f

static int hpfb_init_one(unsigned long phys_base, unsigned long virt_base)
{
        unsigned long fboff, fb_width, fb_height, fb_start;
        int ret;

        fb_regs = virt_base;
        fboff = (in_8(fb_regs + HPFB_FBOMSB) << 8) | in_8(fb_regs + HPFB_FBOLSB);

        fb_info.fix.smem_start = (in_8(fb_regs + fboff) << 16);

        if (phys_base >= DIOII_BASE) {
                fb_info.fix.smem_start += phys_base;
        }

        if (DIO_SECID(fb_regs) != DIO_ID2_TOPCAT) {
                /* This is the magic incantation the HP X server uses to make Catseye boards work. */
                while (in_be16(fb_regs+0x4800) & 1)
                        ;
                out_be16(fb_regs+0x4800, 0);    /* Catseye status */
                out_be16(fb_regs+0x4510, 0);    /* VB */
                out_be16(fb_regs+0x4512, 0);    /* TCNTRL */
                out_be16(fb_regs+0x4514, 0);    /* ACNTRL */
                out_be16(fb_regs+0x4516, 0);    /* PNCNTRL */
                out_be16(fb_regs+0x4206, 0x90); /* RUG Command/Status */
                out_be16(fb_regs+0x60a2, 0);    /* Overlay Mask */
                out_be16(fb_regs+0x60bc, 0);    /* Ram Select */
        }

        /*
         *      Fill in the available video resolution
         */
        fb_width = (in_8(fb_regs + HPFB_FBWMSB) << 8) | in_8(fb_regs + HPFB_FBWLSB);
        fb_info.fix.line_length = fb_width;
        fb_height = (in_8(fb_regs + HPFB_FBHMSB) << 8) | in_8(fb_regs + HPFB_FBHLSB);
        fb_info.fix.smem_len = fb_width * fb_height;
        fb_start = (unsigned long)ioremap_wt(fb_info.fix.smem_start,
                                             fb_info.fix.smem_len);
        hpfb_defined.xres = (in_8(fb_regs + HPFB_DWMSB) << 8) | in_8(fb_regs + HPFB_DWLSB);
        hpfb_defined.yres = (in_8(fb_regs + HPFB_DHMSB) << 8) | in_8(fb_regs + HPFB_DHLSB);
        hpfb_defined.xres_virtual = hpfb_defined.xres;
        hpfb_defined.yres_virtual = hpfb_defined.yres;
        hpfb_defined.bits_per_pixel = in_8(fb_regs + HPFB_NUMPLANES);

        printk(KERN_INFO "hpfb: framebuffer at 0x%lx, mapped to 0x%lx, size %dk\n",
               fb_info.fix.smem_start, fb_start, fb_info.fix.smem_len/1024);
        printk(KERN_INFO "hpfb: mode is %dx%dx%d, linelength=%d\n",
               hpfb_defined.xres, hpfb_defined.yres, hpfb_defined.bits_per_pixel, fb_info.fix.line_length);

        /*
         *      Give the hardware a bit of a prod and work out how many bits per
         *      pixel are supported.
         */
        out_8(fb_regs + TC_WEN, 0xff);
        out_8(fb_regs + TC_PRR, RR_COPY);
        out_8(fb_regs + TC_FBEN, 0xff);
        out_8(fb_start, 0xff);
        fb_bitmask = in_8(fb_start);
        out_8(fb_start, 0);

        /*
         *      Enable reading/writing of all the planes.
         */
        out_8(fb_regs + TC_WEN, fb_bitmask);
        out_8(fb_regs + TC_PRR, RR_COPY);
        out_8(fb_regs + TC_REN, fb_bitmask);
        out_8(fb_regs + TC_FBEN, fb_bitmask);

        /*
         *      Clear the screen.
         */
        topcat_blit(0, 0, 0, 0, fb_width, fb_height, RR_CLEAR);

        /*
         *      Let there be consoles..
         */
        if (DIO_SECID(fb_regs) == DIO_ID2_TOPCAT)
                strcat(fb_info.fix.id, "Topcat");
        else
                strcat(fb_info.fix.id, "Catseye");
        fb_info.fbops = &hpfb_ops;
        fb_info.var   = hpfb_defined;
        fb_info.screen_base = (char *)fb_start;

        ret = fb_alloc_cmap(&fb_info.cmap, 1 << hpfb_defined.bits_per_pixel, 0);
        if (ret < 0)
                goto unmap_screen_base;

        ret = register_framebuffer(&fb_info);
        if (ret < 0)
                goto dealloc_cmap;

        fb_info(&fb_info, "%s frame buffer device\n", fb_info.fix.id);

        return 0;

dealloc_cmap:
        fb_dealloc_cmap(&fb_info.cmap);

unmap_screen_base:
        if (fb_info.screen_base) {
                iounmap(fb_info.screen_base);
                fb_info.screen_base = NULL;
        }

        return ret;
}

/*
 * Check that the secondary ID indicates that we have some hope of working with this
 * framebuffer.  The catseye boards are pretty much like topcats and we can muddle through.
 */

#define topcat_sid_ok(x)  (((x) == DIO_ID2_LRCATSEYE) || ((x) == DIO_ID2_HRCCATSEYE)    \
                           || ((x) == DIO_ID2_HRMCATSEYE) || ((x) == DIO_ID2_TOPCAT))

/*
 * Initialise the framebuffer
 */
static int hpfb_dio_probe(struct dio_dev *d, const struct dio_device_id *ent)
{
        unsigned long paddr, vaddr;

        paddr = d->resource.start;
        if (!request_mem_region(d->resource.start, resource_size(&d->resource), d->name))
                return -EBUSY;

        if (d->scode >= DIOII_SCBASE) {
                vaddr = (unsigned long)ioremap(paddr, resource_size(&d->resource));
        } else {
                vaddr = paddr + DIO_VIRADDRBASE;
        }
        printk(KERN_INFO "Topcat found at DIO select code %d "
               "(secondary id %02x)\n", d->scode, (d->id >> 8) & 0xff);
        if (hpfb_init_one(paddr, vaddr)) {
                if (d->scode >= DIOII_SCBASE)
                        iounmap((void *)vaddr);
                release_mem_region(d->resource.start, resource_size(&d->resource));
                return -ENOMEM;
        }
        return 0;
}

static void hpfb_remove_one(struct dio_dev *d)
{
        unregister_framebuffer(&fb_info);
        if (d->scode >= DIOII_SCBASE)
                iounmap((void *)fb_regs);
        release_mem_region(d->resource.start, resource_size(&d->resource));
        fb_dealloc_cmap(&fb_info.cmap);
        if (fb_info.screen_base)
                iounmap(fb_info.screen_base);
}

static struct dio_device_id hpfb_dio_tbl[] = {
    { DIO_ENCODE_ID(DIO_ID_FBUFFER, DIO_ID2_LRCATSEYE) },
    { DIO_ENCODE_ID(DIO_ID_FBUFFER, DIO_ID2_HRCCATSEYE) },
    { DIO_ENCODE_ID(DIO_ID_FBUFFER, DIO_ID2_HRMCATSEYE) },
    { DIO_ENCODE_ID(DIO_ID_FBUFFER, DIO_ID2_TOPCAT) },
    { 0 }
};

static struct dio_driver hpfb_driver = {
    .name      = "hpfb",
    .id_table  = hpfb_dio_tbl,
    .probe     = hpfb_dio_probe,
    .remove    = hpfb_remove_one,
};

static int __init hpfb_init(void)
{
        unsigned int sid;
        unsigned char i;
        int err;

        /* Topcats can be on the internal IO bus or real DIO devices.
         * The internal variant sits at 0x560000; it has primary
         * and secondary ID registers just like the DIO version.
         * So we merge the two detection routines.
         *
         * Perhaps this #define should be in a global header file:
         * I believe it's common to all internal fbs, not just topcat.
         */
#define INTFBVADDR 0xf0560000
#define INTFBPADDR 0x560000

        if (!MACH_IS_HP300)
                return -ENODEV;

        if (fb_get_options("hpfb", NULL))
                return -ENODEV;

        err = dio_register_driver(&hpfb_driver);
        if (err)
                return err;

        err = copy_from_kernel_nofault(&i, (unsigned char *)INTFBVADDR + DIO_IDOFF, 1);

        if (!err && (i == DIO_ID_FBUFFER) && topcat_sid_ok(sid = DIO_SECID(INTFBVADDR))) {
                if (!request_mem_region(INTFBPADDR, DIO_DEVSIZE, "Internal Topcat"))
                        return -EBUSY;
                printk(KERN_INFO "Internal Topcat found (secondary id %02x)\n", sid);
                if (hpfb_init_one(INTFBPADDR, INTFBVADDR)) {
                        return -ENOMEM;
                }
        }
        return 0;
}

static void __exit hpfb_cleanup_module(void)
{
        dio_unregister_driver(&hpfb_driver);
}

module_init(hpfb_init);
module_exit(hpfb_cleanup_module);

MODULE_LICENSE("GPL");