pmag-ba-fb.c

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/*
 *  linux/drivers/video/pmag-ba-fb.c
 *
 *  PMAG-BA TURBOchannel Color Frame Buffer (CFB) card support,
 *  derived from:
 *  "HP300 Topcat framebuffer support (derived from macfb of all things)
 *  Phil Blundell <[email protected]> 1998", the original code can be
 *  found in the file hpfb.c in the same directory.
 *
 *  Based on digital document:
 *  "PMAG-BA TURBOchannel Color Frame Buffer
 *   Functional Specification", Revision 1.2, August 27, 1990
 *
 *  DECstation related code Copyright (C) 1999, 2000, 2001 by
 *  Michael Engel <[email protected]>,
 *  Karsten Merker <[email protected]> and
 *  Harald Koerfgen.
 *  Copyright (c) 2005, 2006  Maciej W. Rozycki
 *  Copyright (c) 2005  James Simmons
 *
 *  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/compiler.h>
#include <linux/errno.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/tc.h>
#include <linux/types.h>

#include <asm/io.h>

#include <video/pmag-ba-fb.h>


struct pmagbafb_par {
    volatile void __iomem *mmio;
    volatile u32 __iomem *dac;
};


static struct fb_var_screeninfo pmagbafb_defined __devinitdata = {
    .xres       = 1024,
    .yres       = 864,
    .xres_virtual   = 1024,
    .yres_virtual   = 864,
    .bits_per_pixel = 8,
    .red.length = 8,
    .green.length   = 8,
    .blue.length    = 8,
    .activate   = FB_ACTIVATE_NOW,
    .height     = -1,
    .width      = -1,
    .accel_flags    = FB_ACCEL_NONE,
    .pixclock   = 14452,
    .left_margin    = 116,
    .right_margin   = 12,
    .upper_margin   = 34,
    .lower_margin   = 12,
    .hsync_len  = 128,
    .vsync_len  = 3,
    .sync       = FB_SYNC_ON_GREEN,
    .vmode      = FB_VMODE_NONINTERLACED,
};

static struct fb_fix_screeninfo pmagbafb_fix __devinitdata = {
    .id     = "PMAG-BA",
    .smem_len   = (1024 * 1024),
    .type       = FB_TYPE_PACKED_PIXELS,
    .visual     = FB_VISUAL_PSEUDOCOLOR,
    .line_length    = 1024,
    .mmio_len   = PMAG_BA_SIZE - PMAG_BA_BT459,
};


static inline void dac_write(struct pmagbafb_par *par, unsigned int reg, u8 v)
{
    writeb(v, par->dac + reg / 4);
}

static inline u8 dac_read(struct pmagbafb_par *par, unsigned int reg)
{
    return readb(par->dac + reg / 4);
}


/*
 * Set the palette.
 */
static int pmagbafb_setcolreg(unsigned int regno, unsigned int red,
                  unsigned int green, unsigned int blue,
                  unsigned int transp, struct fb_info *info)
{
    struct pmagbafb_par *par = info->par;

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

    red   >>= 8;    /* The cmap fields are 16 bits    */
    green >>= 8;    /* wide, but the hardware colormap */
    blue  >>= 8;    /* registers are only 8 bits wide */

    mb();
    dac_write(par, BT459_ADDR_LO, regno);
    dac_write(par, BT459_ADDR_HI, 0x00);
    wmb();
    dac_write(par, BT459_CMAP, red);
    wmb();
    dac_write(par, BT459_CMAP, green);
    wmb();
    dac_write(par, BT459_CMAP, blue);

    return 0;
}

static struct fb_ops pmagbafb_ops = {
    .owner      = THIS_MODULE,
    .fb_setcolreg   = pmagbafb_setcolreg,
    .fb_fillrect    = cfb_fillrect,
    .fb_copyarea    = cfb_copyarea,
    .fb_imageblit   = cfb_imageblit,
};


/*
 * Turn the hardware cursor off.
 */
static void __init pmagbafb_erase_cursor(struct fb_info *info)
{
    struct pmagbafb_par *par = info->par;

    mb();
    dac_write(par, BT459_ADDR_LO, 0x00);
    dac_write(par, BT459_ADDR_HI, 0x03);
    wmb();
    dac_write(par, BT459_DATA, 0x00);
}


static int __devinit pmagbafb_probe(struct device *dev)
{
    struct tc_dev *tdev = to_tc_dev(dev);
    resource_size_t start, len;
    struct fb_info *info;
    struct pmagbafb_par *par;
    int err;

    info = framebuffer_alloc(sizeof(struct pmagbafb_par), dev);
    if (!info) {
        printk(KERN_ERR "%s: Cannot allocate memory\n", dev_name(dev));
        return -ENOMEM;
    }

    par = info->par;
    dev_set_drvdata(dev, info);

    if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
        printk(KERN_ERR "%s: Cannot allocate color map\n",
               dev_name(dev));
        err = -ENOMEM;
        goto err_alloc;
    }

    info->fbops = &pmagbafb_ops;
    info->fix = pmagbafb_fix;
    info->var = pmagbafb_defined;
    info->flags = FBINFO_DEFAULT;

    /* Request the I/O MEM resource.  */
    start = tdev->resource.start;
    len = tdev->resource.end - start + 1;
    if (!request_mem_region(start, len, dev_name(dev))) {
        printk(KERN_ERR "%s: Cannot reserve FB region\n",
               dev_name(dev));
        err = -EBUSY;
        goto err_cmap;
    }

    /* MMIO mapping setup.  */
    info->fix.mmio_start = start;
    par->mmio = ioremap_nocache(info->fix.mmio_start, info->fix.mmio_len);
    if (!par->mmio) {
        printk(KERN_ERR "%s: Cannot map MMIO\n", dev_name(dev));
        err = -ENOMEM;
        goto err_resource;
    }
    par->dac = par->mmio + PMAG_BA_BT459;

    /* Frame buffer mapping setup.  */
    info->fix.smem_start = start + PMAG_BA_FBMEM;
    info->screen_base = ioremap_nocache(info->fix.smem_start,
                        info->fix.smem_len);
    if (!info->screen_base) {
        printk(KERN_ERR "%s: Cannot map FB\n", dev_name(dev));
        err = -ENOMEM;
        goto err_mmio_map;
    }
    info->screen_size = info->fix.smem_len;

    pmagbafb_erase_cursor(info);

    err = register_framebuffer(info);
    if (err < 0) {
        printk(KERN_ERR "%s: Cannot register framebuffer\n",
               dev_name(dev));
        goto err_smem_map;
    }

    get_device(dev);

    pr_info("fb%d: %s frame buffer device at %s\n",
        info->node, info->fix.id, dev_name(dev));

    return 0;


err_smem_map:
    iounmap(info->screen_base);

err_mmio_map:
    iounmap(par->mmio);

err_resource:
    release_mem_region(start, len);

err_cmap:
    fb_dealloc_cmap(&info->cmap);

err_alloc:
    framebuffer_release(info);
    return err;
}

static int __exit pmagbafb_remove(struct device *dev)
{
    struct tc_dev *tdev = to_tc_dev(dev);
    struct fb_info *info = dev_get_drvdata(dev);
    struct pmagbafb_par *par = info->par;
    resource_size_t start, len;

    put_device(dev);
    unregister_framebuffer(info);
    iounmap(info->screen_base);
    iounmap(par->mmio);
    start = tdev->resource.start;
    len = tdev->resource.end - start + 1;
    release_mem_region(start, len);
    fb_dealloc_cmap(&info->cmap);
    framebuffer_release(info);
    return 0;
}


/*
 * Initialize the framebuffer.
 */
static const struct tc_device_id pmagbafb_tc_table[] = {
    { "DEC     ", "PMAG-BA " },
    { }
};
MODULE_DEVICE_TABLE(tc, pmagbafb_tc_table);

static struct tc_driver pmagbafb_driver = {
    .id_table   = pmagbafb_tc_table,
    .driver     = {
        .name   = "pmagbafb",
        .bus    = &tc_bus_type,
        .probe  = pmagbafb_probe,
        .remove = __exit_p(pmagbafb_remove),
    },
};

static int __init pmagbafb_init(void)
{
#ifndef MODULE
    if (fb_get_options("pmagbafb", NULL))
        return -ENXIO;
#endif
    return tc_register_driver(&pmagbafb_driver);
}

static void __exit pmagbafb_exit(void)
{
    tc_unregister_driver(&pmagbafb_driver);
}


module_init(pmagbafb_init);
module_exit(pmagbafb_exit);

MODULE_LICENSE("GPL");