grvga.c

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/*
 * Driver for Aeroflex Gaisler SVGACTRL framebuffer device.
 *
 * 2011 (c) Aeroflex Gaisler AB
 *
 * Full documentation of the core can be found here:
 * http://www.gaisler.com/products/grlib/grip.pdf
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * Contributors: Kristoffer Glembo <[email protected]>
 *
 */

#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/of_platform.h>
#include <linux/of_device.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/mm.h>
#include <linux/fb.h>
#include <linux/io.h>

struct grvga_regs {
    u32 status;         /* 0x00 */
    u32 video_length;   /* 0x04 */
    u32 front_porch;    /* 0x08 */
    u32 sync_length;    /* 0x0C */
    u32 line_length;    /* 0x10 */
    u32 fb_pos;     /* 0x14 */
    u32 clk_vector[4];  /* 0x18 */
    u32 clut;           /* 0x20 */
};

struct grvga_par {
    struct grvga_regs *regs;
    u32 color_palette[16];  /* 16 entry pseudo palette used by fbcon in true color mode */
    int clk_sel;
    int fb_alloced;         /* = 1 if framebuffer is allocated in main memory */
};


static const struct fb_videomode grvga_modedb[] = {
    {
    /* 640x480 @ 60 Hz */
    NULL, 60, 640, 480, 40000, 48, 16, 39, 11, 96, 2,
    0, FB_VMODE_NONINTERLACED
    }, {
    /* 800x600 @ 60 Hz */
    NULL, 60, 800, 600, 25000, 88, 40, 23, 1, 128, 4,
    0, FB_VMODE_NONINTERLACED
    }, {
    /* 800x600 @ 72 Hz */
    NULL, 72, 800, 600, 20000, 64, 56, 23, 37, 120, 6,
    0, FB_VMODE_NONINTERLACED
    }, {
    /* 1024x768 @ 60 Hz */
    NULL, 60, 1024, 768, 15385, 160, 24, 29, 3, 136, 6,
    0, FB_VMODE_NONINTERLACED
    }
 };

static struct fb_fix_screeninfo grvga_fix __devinitdata = {
    .id =       "AG SVGACTRL",
    .type =     FB_TYPE_PACKED_PIXELS,
    .visual =       FB_VISUAL_PSEUDOCOLOR,
    .xpanstep = 0,
    .ypanstep = 1,
    .ywrapstep =    0,
    .accel =    FB_ACCEL_NONE,
};

static int grvga_check_var(struct fb_var_screeninfo *var,
               struct fb_info *info)
{
    struct grvga_par *par = info->par;
    int i;

    if (!var->xres)
        var->xres = 1;
    if (!var->yres)
        var->yres = 1;
    if (var->bits_per_pixel <= 8)
        var->bits_per_pixel = 8;
    else if (var->bits_per_pixel <= 16)
        var->bits_per_pixel = 16;
    else if (var->bits_per_pixel <= 24)
        var->bits_per_pixel = 24;
    else if (var->bits_per_pixel <= 32)
        var->bits_per_pixel = 32;
    else
        return -EINVAL;

    var->xres_virtual = var->xres;
    var->yres_virtual = 2*var->yres;

    if (info->fix.smem_len) {
        if ((var->yres_virtual*var->xres_virtual*var->bits_per_pixel/8) > info->fix.smem_len)
            return -ENOMEM;
    }

    /* Which clocks that are available can be read out in these registers */
    for (i = 0; i <= 3 ; i++) {
        if (var->pixclock == par->regs->clk_vector[i])
            break;
    }
    if (i <= 3)
        par->clk_sel = i;
    else
        return -EINVAL;

    switch (info->var.bits_per_pixel) {
    case 8:
        var->red   = (struct fb_bitfield) {0, 8, 0};      /* offset, length, msb-right */
        var->green = (struct fb_bitfield) {0, 8, 0};
        var->blue  = (struct fb_bitfield) {0, 8, 0};
        var->transp = (struct fb_bitfield) {0, 0, 0};
        break;
    case 16:
        var->red   = (struct fb_bitfield) {11, 5, 0};
        var->green = (struct fb_bitfield) {5, 6, 0};
        var->blue  = (struct fb_bitfield) {0, 5, 0};
        var->transp = (struct fb_bitfield) {0, 0, 0};
        break;
    case 24:
    case 32:
        var->red   = (struct fb_bitfield) {16, 8, 0};
        var->green = (struct fb_bitfield) {8, 8, 0};
        var->blue  = (struct fb_bitfield) {0, 8, 0};
        var->transp = (struct fb_bitfield) {24, 8, 0};
        break;
    default:
        return -EINVAL;
    }

    return 0;
}

static int grvga_set_par(struct fb_info *info)
{

    u32 func = 0;
    struct grvga_par *par = info->par;

    __raw_writel(((info->var.yres - 1) << 16) | (info->var.xres - 1),
             &par->regs->video_length);

    __raw_writel((info->var.lower_margin << 16) | (info->var.right_margin),
             &par->regs->front_porch);

    __raw_writel((info->var.vsync_len << 16) | (info->var.hsync_len),
             &par->regs->sync_length);

    __raw_writel(((info->var.yres + info->var.lower_margin + info->var.upper_margin + info->var.vsync_len - 1) << 16) |
             (info->var.xres + info->var.right_margin + info->var.left_margin + info->var.hsync_len - 1),
             &par->regs->line_length);

    switch (info->var.bits_per_pixel) {
    case 8:
        info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
        func = 1;
        break;
    case 16:
        info->fix.visual = FB_VISUAL_TRUECOLOR;
        func = 2;
        break;
    case 24:
    case 32:
        info->fix.visual = FB_VISUAL_TRUECOLOR;
        func = 3;
        break;
    default:
        return -EINVAL;
    }

    __raw_writel((par->clk_sel << 6) | (func << 4) | 1,
             &par->regs->status);

    info->fix.line_length = (info->var.xres_virtual*info->var.bits_per_pixel)/8;
    return 0;
}

static int grvga_setcolreg(unsigned regno, unsigned red, unsigned green, unsigned blue, unsigned transp, struct fb_info *info)
{
    struct grvga_par *par;
    par = info->par;

    if (regno >= 256)   /* Size of CLUT */
        return -EINVAL;

    if (info->var.grayscale) {
        /* grayscale = 0.30*R + 0.59*G + 0.11*B */
        red = green = blue = (red * 77 + green * 151 + blue * 28) >> 8;
    }



#define CNVT_TOHW(val, width) ((((val)<<(width))+0x7FFF-(val))>>16)

    red    = CNVT_TOHW(red,   info->var.red.length);
    green  = CNVT_TOHW(green, info->var.green.length);
    blue   = CNVT_TOHW(blue,  info->var.blue.length);
    transp = CNVT_TOHW(transp, info->var.transp.length);

#undef CNVT_TOHW

    /* In PSEUDOCOLOR we use the hardware CLUT */
    if (info->fix.visual == FB_VISUAL_PSEUDOCOLOR)
        __raw_writel((regno << 24) | (red << 16) | (green << 8) | blue,
                 &par->regs->clut);

    /* Truecolor uses the pseudo palette */
    else if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
        u32 v;
        if (regno >= 16)
            return -EINVAL;


        v =     (red    << info->var.red.offset)   |
            (green  << info->var.green.offset) |
            (blue   << info->var.blue.offset)  |
            (transp << info->var.transp.offset);

        ((u32 *) (info->pseudo_palette))[regno] = v;
    }
    return 0;
}

static int grvga_pan_display(struct fb_var_screeninfo *var,
                 struct fb_info *info)
{
    struct grvga_par *par = info->par;
    struct fb_fix_screeninfo *fix = &info->fix;
    u32 base_addr;

    if (var->xoffset != 0)
        return -EINVAL;

    base_addr = fix->smem_start + (var->yoffset * fix->line_length);
    base_addr &= ~3UL;

    /* Set framebuffer base address  */
    __raw_writel(base_addr,
             &par->regs->fb_pos);

    return 0;
}

static struct fb_ops grvga_ops = {
    .owner          = THIS_MODULE,
    .fb_check_var   = grvga_check_var,
    .fb_set_par = grvga_set_par,
    .fb_setcolreg   = grvga_setcolreg,
    .fb_pan_display = grvga_pan_display,
    .fb_fillrect    = cfb_fillrect,
    .fb_copyarea    = cfb_copyarea,
    .fb_imageblit   = cfb_imageblit
};

static int __devinit grvga_parse_custom(char *options,
                     struct fb_var_screeninfo *screendata)
{
    char *this_opt;
    int count = 0;
    if (!options || !*options)
        return -1;

    while ((this_opt = strsep(&options, " ")) != NULL) {
        if (!*this_opt)
            continue;

        switch (count) {
        case 0:
            screendata->pixclock = simple_strtoul(this_opt, NULL, 0);
            count++;
            break;
        case 1:
            screendata->xres = screendata->xres_virtual = simple_strtoul(this_opt, NULL, 0);
            count++;
            break;
        case 2:
            screendata->right_margin = simple_strtoul(this_opt, NULL, 0);
            count++;
            break;
        case 3:
            screendata->hsync_len = simple_strtoul(this_opt, NULL, 0);
            count++;
            break;
        case 4:
            screendata->left_margin = simple_strtoul(this_opt, NULL, 0);
            count++;
            break;
        case 5:
            screendata->yres = screendata->yres_virtual = simple_strtoul(this_opt, NULL, 0);
            count++;
            break;
        case 6:
            screendata->lower_margin = simple_strtoul(this_opt, NULL, 0);
            count++;
            break;
        case 7:
            screendata->vsync_len = simple_strtoul(this_opt, NULL, 0);
            count++;
            break;
        case 8:
            screendata->upper_margin = simple_strtoul(this_opt, NULL, 0);
            count++;
            break;
        case 9:
            screendata->bits_per_pixel = simple_strtoul(this_opt, NULL, 0);
            count++;
            break;
        default:
            return -1;
        }
    }
    screendata->activate  = FB_ACTIVATE_NOW;
    screendata->vmode     = FB_VMODE_NONINTERLACED;
    return 0;
}

static int __devinit grvga_probe(struct platform_device *dev)
{
    struct fb_info *info;
    int retval = -ENOMEM;
    unsigned long virtual_start;
    unsigned long grvga_fix_addr = 0;
    unsigned long physical_start = 0;
    unsigned long grvga_mem_size = 0;
    struct grvga_par *par = NULL;
    char *options = NULL, *mode_opt = NULL;

    info = framebuffer_alloc(sizeof(struct grvga_par), &dev->dev);
    if (!info) {
        dev_err(&dev->dev, "framebuffer_alloc failed\n");
        return -ENOMEM;
    }

    /* Expecting: "grvga: modestring, [addr:<framebuffer physical address>], [size:<framebuffer size>]
     *
     * If modestring is custom:<custom mode string> we parse the string which then contains all videoparameters
     * If address is left out, we allocate memory,
     * if size is left out we only allocate enough to support the given mode.
     */
    if (fb_get_options("grvga", &options)) {
        retval = -ENODEV;
        goto free_fb;
    }

    if (!options || !*options)
        options =  "640x480-8@60";

    while (1) {
        char *this_opt = strsep(&options, ",");

        if (!this_opt)
            break;

        if (!strncmp(this_opt, "custom", 6)) {
            if (grvga_parse_custom(this_opt, &info->var) < 0) {
                dev_err(&dev->dev, "Failed to parse custom mode (%s).\n", this_opt);
                retval = -EINVAL;
                goto free_fb;
            }
        } else if (!strncmp(this_opt, "addr", 4))
            grvga_fix_addr = simple_strtoul(this_opt + 5, NULL, 16);
        else if (!strncmp(this_opt, "size", 4))
            grvga_mem_size = simple_strtoul(this_opt + 5, NULL, 0);
        else
            mode_opt = this_opt;
    }

    par = info->par;
    info->fbops = &grvga_ops;
    info->fix = grvga_fix;
    info->pseudo_palette = par->color_palette;
    info->flags = FBINFO_DEFAULT | FBINFO_PARTIAL_PAN_OK | FBINFO_HWACCEL_YPAN;
    info->fix.smem_len = grvga_mem_size;

    if (!devm_request_mem_region(&dev->dev, dev->resource[0].start,
            resource_size(&dev->resource[0]), "grlib-svgactrl regs")) {
        dev_err(&dev->dev, "registers already mapped\n");
        retval = -EBUSY;
        goto free_fb;
    }

    par->regs = of_ioremap(&dev->resource[0], 0,
                   resource_size(&dev->resource[0]),
                   "grlib-svgactrl regs");

    if (!par->regs) {
        dev_err(&dev->dev, "failed to map registers\n");
        retval = -ENOMEM;
        goto free_fb;
    }

    retval = fb_alloc_cmap(&info->cmap, 256, 0);
    if (retval < 0) {
        dev_err(&dev->dev, "failed to allocate mem with fb_alloc_cmap\n");
        retval = -ENOMEM;
        goto unmap_regs;
    }

    if (mode_opt) {
        retval = fb_find_mode(&info->var, info, mode_opt,
                      grvga_modedb, sizeof(grvga_modedb), &grvga_modedb[0], 8);
        if (!retval || retval == 4) {
            retval = -EINVAL;
            goto dealloc_cmap;
        }
    }

    if (!grvga_mem_size)
        grvga_mem_size = info->var.xres_virtual * info->var.yres_virtual * info->var.bits_per_pixel/8;

    if (grvga_fix_addr) {
        /* Got framebuffer base address from argument list */

        physical_start = grvga_fix_addr;

        if (!devm_request_mem_region(&dev->dev, physical_start,
                         grvga_mem_size, dev->name)) {
            dev_err(&dev->dev, "failed to request memory region\n");
            retval = -ENOMEM;
            goto dealloc_cmap;
        }

        virtual_start = (unsigned long) ioremap(physical_start, grvga_mem_size);

        if (!virtual_start) {
            dev_err(&dev->dev, "error mapping framebuffer memory\n");
            retval = -ENOMEM;
            goto dealloc_cmap;
        }
    } else {    /* Allocate frambuffer memory */

        unsigned long page;

        virtual_start = (unsigned long) __get_free_pages(GFP_DMA,
                                 get_order(grvga_mem_size));
        if (!virtual_start) {
            dev_err(&dev->dev,
                "unable to allocate framebuffer memory (%lu bytes)\n",
                grvga_mem_size);
            retval = -ENOMEM;
            goto dealloc_cmap;
        }

        physical_start = dma_map_single(&dev->dev, (void *)virtual_start, grvga_mem_size, DMA_TO_DEVICE);

        /* Set page reserved so that mmap will work. This is necessary
         * since we'll be remapping normal memory.
         */
        for (page = virtual_start;
             page < PAGE_ALIGN(virtual_start + grvga_mem_size);
             page += PAGE_SIZE) {
            SetPageReserved(virt_to_page(page));
        }

        par->fb_alloced = 1;
    }

    memset((unsigned long *) virtual_start, 0, grvga_mem_size);

    info->screen_base = (char __iomem *) virtual_start;
    info->fix.smem_start = physical_start;
    info->fix.smem_len   = grvga_mem_size;

    dev_set_drvdata(&dev->dev, info);

    dev_info(&dev->dev,
         "Aeroflex Gaisler framebuffer device (fb%d), %dx%d-%d, using %luK of video memory @ %p\n",
         info->node, info->var.xres, info->var.yres, info->var.bits_per_pixel,
         grvga_mem_size >> 10, info->screen_base);

    retval = register_framebuffer(info);
    if (retval < 0) {
        dev_err(&dev->dev, "failed to register framebuffer\n");
        goto free_mem;
    }

    __raw_writel(physical_start, &par->regs->fb_pos);
    __raw_writel(__raw_readl(&par->regs->status) | 1,  /* Enable framebuffer */
             &par->regs->status);

    return 0;

free_mem:
    dev_set_drvdata(&dev->dev, NULL);
    if (grvga_fix_addr)
        iounmap((void *)virtual_start);
    else
        kfree((void *)virtual_start);
dealloc_cmap:
    fb_dealloc_cmap(&info->cmap);
unmap_regs:
    of_iounmap(&dev->resource[0], par->regs,
           resource_size(&dev->resource[0]));
free_fb:
    framebuffer_release(info);

    return retval;
}

static int __devexit grvga_remove(struct platform_device *device)
{
    struct fb_info *info = dev_get_drvdata(&device->dev);
    struct grvga_par *par = info->par;

    if (info) {
        unregister_framebuffer(info);
        fb_dealloc_cmap(&info->cmap);

        of_iounmap(&device->resource[0], par->regs,
               resource_size(&device->resource[0]));

        if (!par->fb_alloced)
            iounmap(info->screen_base);
        else
            kfree((void *)info->screen_base);

        framebuffer_release(info);
        dev_set_drvdata(&device->dev, NULL);
    }

    return 0;
}

static struct of_device_id svgactrl_of_match[] = {
    {
        .name = "GAISLER_SVGACTRL",
    },
    {
        .name = "01_063",
    },
    {},
};
MODULE_DEVICE_TABLE(of, svgactrl_of_match);

static struct platform_driver grvga_driver = {
    .driver = {
        .name = "grlib-svgactrl",
        .owner = THIS_MODULE,
        .of_match_table = svgactrl_of_match,
    },
    .probe      = grvga_probe,
    .remove     = __devexit_p(grvga_remove),
};


static int __init grvga_init(void)
{
    return platform_driver_register(&grvga_driver);
}

static void __exit grvga_exit(void)
{
    platform_driver_unregister(&grvga_driver);
}

module_init(grvga_init);
module_exit(grvga_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Aeroflex Gaisler");
MODULE_DESCRIPTION("Aeroflex Gaisler framebuffer device driver");