/*
 *  valkyriefb.c -- frame buffer device for the PowerMac 'valkyrie' display
 *
 *  Created 8 August 1998 by
 *  Martin Costabel <costabel@wanadoo.fr> and Kevin Schoedel
 *
 *  Vmode-switching changes and vmode 15/17 modifications created 29 August
 *  1998 by Barry K. Nathan <barryn@pobox.com>.
 *
 *  Ported to m68k Macintosh by David Huggins-Daines <dhd@debian.org>
 *
 *  Derived directly from:
 *
 *   controlfb.c -- frame buffer device for the PowerMac 'control' display
 *   Copyright (C) 1998 Dan Jacobowitz <dan@debian.org>
 *
 *   pmc-valkyrie.c -- Console support for PowerMac "valkyrie" display adaptor.
 *   Copyright (C) 1997 Paul Mackerras.
 *
 *  and indirectly:
 *
 *  Frame buffer structure from:
 *    drivers/video/chipsfb.c -- frame buffer device for
 *    Chips & Technologies 65550 chip.
 *
 *    Copyright (C) 1998 Paul Mackerras
 *
 *    This file is derived from the Powermac "chips" driver:
 *    Copyright (C) 1997 Fabio Riccardi.
 *    And from the frame buffer device for Open Firmware-initialized devices:
 *    Copyright (C) 1997 Geert Uytterhoeven.
 *
 *  Hardware information from:
 *    control.c: Console support for PowerMac "control" display adaptor.
 *    Copyright (C) 1996 Paul Mackerras
 *
 *  This file is subject to the terms and conditions of the GNU General Public
 *  License. See the file COPYING in the main directory of this archive for
 *  more details.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/fb.h>
#include <linux/selection.h>
#include <linux/init.h>
#include <linux/nvram.h>
#include <linux/adb.h>
#include <linux/cuda.h>
#include <linux/of_address.h>
#ifdef CONFIG_MAC
#include <asm/macintosh.h>
#endif

#include "macmodes.h"
#include "valkyriefb.h"

static int default_vmode = VMODE_NVRAM;
static int default_cmode = CMODE_NVRAM;

struct fb_par_valkyrie {
        int     vmode, cmode;
        int     xres, yres;
        int     vxres, vyres;
        struct valkyrie_regvals *init;
};

struct fb_info_valkyrie {
        struct fb_info          info;
        struct fb_par_valkyrie  par;
        struct cmap_regs        __iomem *cmap_regs;
        unsigned long           cmap_regs_phys;

        struct valkyrie_regs    __iomem *valkyrie_regs;
        unsigned long           valkyrie_regs_phys;

        __u8                    __iomem *frame_buffer;
        unsigned long           frame_buffer_phys;

        int                     sense;
        unsigned long           total_vram;

        u32                     pseudo_palette[16];
};

static int valkyriefb_setup(char*);

static int valkyriefb_check_var(struct fb_var_screeninfo *var,
                                struct fb_info *info);
static int valkyriefb_set_par(struct fb_info *info);
static int valkyriefb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
                             u_int transp, struct fb_info *info);
static int valkyriefb_blank(int blank_mode, struct fb_info *info);

static int read_valkyrie_sense(struct fb_info_valkyrie *p);
static void set_valkyrie_clock(unsigned char *params);
static int valkyrie_var_to_par(struct fb_var_screeninfo *var,
        struct fb_par_valkyrie *par, const struct fb_info *fb_info);

static int valkyrie_init_info(struct fb_info *info, struct fb_info_valkyrie *p);
static void valkyrie_par_to_fix(struct fb_par_valkyrie *par, struct fb_fix_screeninfo *fix);
static void valkyrie_init_fix(struct fb_fix_screeninfo *fix, struct fb_info_valkyrie *p);

static const struct fb_ops valkyriefb_ops = {
        .owner =        THIS_MODULE,
        FB_DEFAULT_IOMEM_OPS,
        .fb_check_var = valkyriefb_check_var,
        .fb_set_par =   valkyriefb_set_par,
        .fb_setcolreg = valkyriefb_setcolreg,
        .fb_blank =     valkyriefb_blank,
};

/* Sets the video mode according to info->var */
static int valkyriefb_set_par(struct fb_info *info)
{
        struct fb_info_valkyrie *p =
                container_of(info, struct fb_info_valkyrie, info);
        volatile struct valkyrie_regs __iomem *valkyrie_regs = p->valkyrie_regs;
        struct fb_par_valkyrie *par = info->par;
        struct valkyrie_regvals *init;
        int err;

        if ((err = valkyrie_var_to_par(&info->var, par, info)))
                return err;

        valkyrie_par_to_fix(par, &info->fix);

        /* Reset the valkyrie */
        out_8(&valkyrie_regs->status.r, 0);
        udelay(100);

        /* Initialize display timing registers */
        init = par->init;
        out_8(&valkyrie_regs->mode.r, init->mode | 0x80);
        out_8(&valkyrie_regs->depth.r, par->cmode + 3);
        set_valkyrie_clock(init->clock_params);
        udelay(100);

        /* Turn on display */
        out_8(&valkyrie_regs->mode.r, init->mode);

        return 0;
}

static inline int valkyrie_par_to_var(struct fb_par_valkyrie *par,
                                      struct fb_var_screeninfo *var)
{
        return mac_vmode_to_var(par->vmode, par->cmode, var);
}

static int
valkyriefb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
        int err;
        struct fb_par_valkyrie par;

        if ((err = valkyrie_var_to_par(var, &par, info)))
                return err;
        valkyrie_par_to_var(&par, var);
        return 0;
}

/*
 *  Blank the screen if blank_mode != 0, else unblank. If blank_mode == NULL
 *  then the caller blanks by setting the CLUT (Color Look Up Table) to all
 *  black. Return 0 if blanking succeeded, != 0 if un-/blanking failed due
 *  to e.g. a video mode which doesn't support it. Implements VESA suspend
 *  and powerdown modes on hardware that supports disabling hsync/vsync:
 *    blank_mode == 2: suspend vsync
 *    blank_mode == 3: suspend hsync
 *    blank_mode == 4: powerdown
 */
static int valkyriefb_blank(int blank_mode, struct fb_info *info)
{
        struct fb_info_valkyrie *p =
                container_of(info, struct fb_info_valkyrie, info);
        struct fb_par_valkyrie *par = info->par;
        struct valkyrie_regvals *init = par->init;

        if (init == NULL)
                return 1;

        switch (blank_mode) {
        case FB_BLANK_UNBLANK:                  /* unblank */
                out_8(&p->valkyrie_regs->mode.r, init->mode);
                break;
        case FB_BLANK_NORMAL:
                return 1;       /* get caller to set CLUT to all black */
        case FB_BLANK_VSYNC_SUSPEND:
        case FB_BLANK_HSYNC_SUSPEND:
                /*
                 * [kps] Value extracted from MacOS. I don't know
                 * whether this bit disables hsync or vsync, or
                 * whether the hardware can do the other as well.
                 */
                out_8(&p->valkyrie_regs->mode.r, init->mode | 0x40);
                break;
        case FB_BLANK_POWERDOWN:
                out_8(&p->valkyrie_regs->mode.r, 0x66);
                break;
        }
        return 0;
}

static int valkyriefb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
                             u_int transp, struct fb_info *info)
{
        struct fb_info_valkyrie *p =
                container_of(info, struct fb_info_valkyrie, info);
        volatile struct cmap_regs __iomem *cmap_regs = p->cmap_regs;
        struct fb_par_valkyrie *par = info->par;

        if (regno > 255)
                return 1;
        red >>= 8;
        green >>= 8;
        blue >>= 8;

        /* tell clut which address to fill */
        out_8(&p->cmap_regs->addr, regno);
        udelay(1);
        /* send one color channel at a time */
        out_8(&cmap_regs->lut, red);
        out_8(&cmap_regs->lut, green);
        out_8(&cmap_regs->lut, blue);

        if (regno < 16 && par->cmode == CMODE_16)
                ((u32 *)info->pseudo_palette)[regno] =
                        (regno << 10) | (regno << 5) | regno;

        return 0;
}

static inline int valkyrie_vram_reqd(int video_mode, int color_mode)
{
        int pitch;
        struct valkyrie_regvals *init = valkyrie_reg_init[video_mode-1];

        if ((pitch = init->pitch[color_mode]) == 0)
                pitch = 2 * init->pitch[0];
        return init->vres * pitch;
}

static void set_valkyrie_clock(unsigned char *params)
{
#ifdef CONFIG_ADB_CUDA
        struct adb_request req;
        int i;

        for (i = 0; i < 3; ++i) {
                cuda_request(&req, NULL, 5, CUDA_PACKET, CUDA_GET_SET_IIC,
                             0x50, i + 1, params[i]);
                while (!req.complete)
                        cuda_poll();
        }
#endif
}

static void __init valkyrie_choose_mode(struct fb_info_valkyrie *p)
{
        p->sense = read_valkyrie_sense(p);
        printk(KERN_INFO "Monitor sense value = 0x%x\n", p->sense);

        /* Try to pick a video mode out of NVRAM if we have one. */
#ifdef CONFIG_PPC_PMAC
        if (IS_REACHABLE(CONFIG_NVRAM) && default_vmode == VMODE_NVRAM)
                default_vmode = nvram_read_byte(NV_VMODE);
#endif
        if (default_vmode <= 0 || default_vmode > VMODE_MAX ||
            !valkyrie_reg_init[default_vmode - 1]) {
                default_vmode = mac_map_monitor_sense(p->sense);
                if (!valkyrie_reg_init[default_vmode - 1])
                        default_vmode = VMODE_640_480_67;
        }

#ifdef CONFIG_PPC_PMAC
        if (IS_REACHABLE(CONFIG_NVRAM) && default_cmode == CMODE_NVRAM)
                default_cmode = nvram_read_byte(NV_CMODE);
#endif
        /*
         * Reduce the pixel size if we don't have enough VRAM or bandwidth.
         */
        if (default_cmode < CMODE_8 || default_cmode > CMODE_16
            || valkyrie_reg_init[default_vmode-1]->pitch[default_cmode] == 0
            || valkyrie_vram_reqd(default_vmode, default_cmode) > p->total_vram)
                default_cmode = CMODE_8;

        printk(KERN_INFO "using video mode %d and color mode %d.\n",
               default_vmode, default_cmode);
}

static int __init valkyriefb_init(void)
{
        struct fb_info_valkyrie *p;
        unsigned long frame_buffer_phys, cmap_regs_phys;
        int err;
        char *option = NULL;

        if (fb_get_options("valkyriefb", &option))
                return -ENODEV;
        valkyriefb_setup(option);

#ifdef CONFIG_MAC
        if (!MACH_IS_MAC)
                return -ENODEV;
        if (!(mac_bi_data.id == MAC_MODEL_Q630
              /* I'm not sure about this one */
            || mac_bi_data.id == MAC_MODEL_P588))
                return -ENODEV;

        /* Hardcoded addresses... welcome to 68k Macintosh country :-) */
        frame_buffer_phys = 0xf9000000;
        cmap_regs_phys = 0x50f24000;
#else /* ppc (!CONFIG_MAC) */
        {
                struct device_node *dp;
                struct resource r;

                dp = of_find_node_by_name(NULL, "valkyrie");
                if (!dp)
                        return 0;

                if (of_address_to_resource(dp, 0, &r)) {
                        printk(KERN_ERR "can't find address for valkyrie\n");
                        of_node_put(dp);
                        return 0;
                }

                frame_buffer_phys = r.start;
                cmap_regs_phys = r.start + 0x304000;
                of_node_put(dp);
        }
#endif /* ppc (!CONFIG_MAC) */

        p = kzalloc_obj(*p, GFP_ATOMIC);
        if (!p)
                return -ENOMEM;

        /* Map in frame buffer and registers */
        if (!request_mem_region(frame_buffer_phys, 0x100000, "valkyriefb")) {
                kfree(p);
                return 0;
        }
        p->total_vram = 0x100000;
        p->frame_buffer_phys = frame_buffer_phys;
#ifdef CONFIG_MAC
        p->frame_buffer = ioremap(frame_buffer_phys, p->total_vram);
#else
        p->frame_buffer = ioremap_wt(frame_buffer_phys, p->total_vram);
#endif
        p->cmap_regs_phys = cmap_regs_phys;
        p->cmap_regs = ioremap(p->cmap_regs_phys, 0x1000);
        p->valkyrie_regs_phys = cmap_regs_phys+0x6000;
        p->valkyrie_regs = ioremap(p->valkyrie_regs_phys, 0x1000);
        err = -ENOMEM;
        if (p->frame_buffer == NULL || p->cmap_regs == NULL
            || p->valkyrie_regs == NULL) {
                printk(KERN_ERR "valkyriefb: couldn't map resources\n");
                goto out_free;
        }

        valkyrie_choose_mode(p);
        mac_vmode_to_var(default_vmode, default_cmode, &p->info.var);
        err = valkyrie_init_info(&p->info, p);
        if (err < 0)
                goto out_free;
        valkyrie_init_fix(&p->info.fix, p);
        if (valkyriefb_set_par(&p->info))
                /* "can't happen" */
                printk(KERN_ERR "valkyriefb: can't set default video mode\n");

        if ((err = register_framebuffer(&p->info)) != 0)
                goto out_cmap_free;

        fb_info(&p->info, "valkyrie frame buffer device\n");
        return 0;

 out_cmap_free:
        fb_dealloc_cmap(&p->info.cmap);
 out_free:
        if (p->frame_buffer)
                iounmap(p->frame_buffer);
        if (p->cmap_regs)
                iounmap(p->cmap_regs);
        if (p->valkyrie_regs)
                iounmap(p->valkyrie_regs);
        kfree(p);
        return err;
}

/*
 * Get the monitor sense value.
 */
static int read_valkyrie_sense(struct fb_info_valkyrie *p)
{
        int sense, in;

        out_8(&p->valkyrie_regs->msense.r, 0);   /* release all lines */
        __delay(20000);
        sense = ((in = in_8(&p->valkyrie_regs->msense.r)) & 0x70) << 4;
        /* drive each sense line low in turn and collect the other 2 */
        out_8(&p->valkyrie_regs->msense.r, 4);   /* drive A low */
        __delay(20000);
        sense |= ((in = in_8(&p->valkyrie_regs->msense.r)) & 0x30);
        out_8(&p->valkyrie_regs->msense.r, 2);   /* drive B low */
        __delay(20000);
        sense |= ((in = in_8(&p->valkyrie_regs->msense.r)) & 0x40) >> 3;
        sense |= (in & 0x10) >> 2;
        out_8(&p->valkyrie_regs->msense.r, 1);   /* drive C low */
        __delay(20000);
        sense |= ((in = in_8(&p->valkyrie_regs->msense.r)) & 0x60) >> 5;

        out_8(&p->valkyrie_regs->msense.r, 7);

        return sense;
}

/*
 * This routine takes a user-supplied var,
 * and picks the best vmode/cmode from it.
 */

/* [bkn] I did a major overhaul of this function.
 *
 * Much of the old code was "swiped by jonh from atyfb.c". Because
 * macmodes has mac_var_to_vmode, I felt that it would be better to
 * rework this function to use that, instead of reinventing the wheel to
 * add support for vmode 17. This was reinforced by the fact that
 * the previously swiped atyfb.c code is no longer there.
 *
 * So, I swiped and adapted platinum_var_to_par (from platinumfb.c), replacing
 * most, but not all, of the old code in the process. One side benefit of
 * swiping the platinumfb code is that we now have more comprehensible error
 * messages when a vmode/cmode switch fails. (Most of the error messages are
 * platinumfb.c, but I added two of my own, and I also changed some commas
 * into colons to make the messages more consistent with other Linux error
 * messages.) In addition, I think the new code *might* fix some vmode-
 * switching oddities, but I'm not sure.
 *
 * There may be some more opportunities for cleanup in here, but this is a
 * good start...
 */

static int valkyrie_var_to_par(struct fb_var_screeninfo *var,
        struct fb_par_valkyrie *par, const struct fb_info *fb_info)
{
        int vmode, cmode;
        struct valkyrie_regvals *init;
        struct fb_info_valkyrie *p =
                container_of(fb_info, struct fb_info_valkyrie, info);

        if (mac_var_to_vmode(var, &vmode, &cmode) != 0) {
                printk(KERN_ERR "valkyriefb: can't do %dx%dx%d.\n",
                       var->xres, var->yres, var->bits_per_pixel);
                return -EINVAL;
        }

        /* Check if we know about the wanted video mode */
        if (vmode < 1 || vmode > VMODE_MAX || !valkyrie_reg_init[vmode-1]) {
                printk(KERN_ERR "valkyriefb: vmode %d not valid.\n", vmode);
                return -EINVAL;
        }

        if (cmode != CMODE_8 && cmode != CMODE_16) {
                printk(KERN_ERR "valkyriefb: cmode %d not valid.\n", cmode);
                return -EINVAL;
        }

        if (var->xres_virtual > var->xres || var->yres_virtual > var->yres
            || var->xoffset != 0 || var->yoffset != 0) {
                return -EINVAL;
        }

        init = valkyrie_reg_init[vmode-1];
        if (init->pitch[cmode] == 0) {
                printk(KERN_ERR "valkyriefb: vmode %d does not support "
                       "cmode %d.\n", vmode, cmode);
                return -EINVAL;
        }

        if (valkyrie_vram_reqd(vmode, cmode) > p->total_vram) {
                printk(KERN_ERR "valkyriefb: not enough ram for vmode %d, "
                       "cmode %d.\n", vmode, cmode);
                return -EINVAL;
        }

        par->vmode = vmode;
        par->cmode = cmode;
        par->init = init;
        par->xres = var->xres;
        par->yres = var->yres;
        par->vxres = par->xres;
        par->vyres = par->yres;

        return 0;
}

static void valkyrie_init_fix(struct fb_fix_screeninfo *fix, struct fb_info_valkyrie *p)
{
        memset(fix, 0, sizeof(*fix));
        strcpy(fix->id, "valkyrie");
        fix->mmio_start = p->valkyrie_regs_phys;
        fix->mmio_len = sizeof(struct valkyrie_regs);
        fix->type = FB_TYPE_PACKED_PIXELS;
        fix->smem_start = p->frame_buffer_phys + 0x1000;
        fix->smem_len = p->total_vram;

        fix->type_aux = 0;
        fix->ywrapstep = 0;
        fix->ypanstep = 0;
        fix->xpanstep = 0;

}

/* Fix must already be inited above */
static void valkyrie_par_to_fix(struct fb_par_valkyrie *par,
        struct fb_fix_screeninfo *fix)
{
        fix->smem_len = valkyrie_vram_reqd(par->vmode, par->cmode);
        fix->visual = (par->cmode == CMODE_8) ?
                FB_VISUAL_PSEUDOCOLOR : FB_VISUAL_DIRECTCOLOR;
        fix->line_length = par->vxres << par->cmode;
                /* ywrapstep, xpanstep, ypanstep */
}

static int __init valkyrie_init_info(struct fb_info *info,
                struct fb_info_valkyrie *p)
{
        info->fbops = &valkyriefb_ops;
        info->screen_base = p->frame_buffer + 0x1000;
        info->pseudo_palette = p->pseudo_palette;
        info->par = &p->par;
        return fb_alloc_cmap(&info->cmap, 256, 0);
}


/*
 * Parse user specified options (`video=valkyriefb:')
 */
static int __init valkyriefb_setup(char *options)
{
        char *this_opt;

        if (!options || !*options)
                return 0;

        while ((this_opt = strsep(&options, ",")) != NULL) {
                if (!strncmp(this_opt, "vmode:", 6)) {
                        int vmode = simple_strtoul(this_opt+6, NULL, 0);
                        if (vmode > 0 && vmode <= VMODE_MAX)
                                default_vmode = vmode;
                }
                else if (!strncmp(this_opt, "cmode:", 6)) {
                        int depth = simple_strtoul(this_opt+6, NULL, 0);
                        switch (depth) {
                        case 8:
                                default_cmode = CMODE_8;
                                break;
                        case 15:
                        case 16:
                                default_cmode = CMODE_16;
                                break;
                        }
                }
        }
        return 0;
}

module_init(valkyriefb_init);
MODULE_LICENSE("GPL");