pmagb-b-fb.c

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/*
 *  linux/drivers/video/pmagb-b-fb.c
 *
 *  PMAGB-B TURBOchannel Smart Frame Buffer (SFB) 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.
 *
 *  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
 *
 *  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/delay.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/pmagb-b-fb.h>


struct pmagbbfb_par {
    volatile void __iomem *mmio;
    volatile void __iomem *smem;
    volatile u32 __iomem *sfb;
    volatile u32 __iomem *dac;
    unsigned int osc0;
    unsigned int osc1;
    int slot;
};


static struct fb_var_screeninfo pmagbbfb_defined __devinitdata = {
    .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,
    .sync       = FB_SYNC_ON_GREEN,
    .vmode      = FB_VMODE_NONINTERLACED,
};

static struct fb_fix_screeninfo pmagbbfb_fix __devinitdata = {
    .id     = "PMAGB-BA",
    .smem_len   = (2048 * 1024),
    .type       = FB_TYPE_PACKED_PIXELS,
    .visual     = FB_VISUAL_PSEUDOCOLOR,
    .mmio_len   = PMAGB_B_FBMEM,
};


static inline void sfb_write(struct pmagbbfb_par *par, unsigned int reg, u32 v)
{
    writel(v, par->sfb + reg / 4);
}

static inline u32 sfb_read(struct pmagbbfb_par *par, unsigned int reg)
{
    return readl(par->sfb + reg / 4);
}

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

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

static inline void gp0_write(struct pmagbbfb_par *par, u32 v)
{
    writel(v, par->mmio + PMAGB_B_GP0);
}


/*
 * Set the palette.
 */
static int pmagbbfb_setcolreg(unsigned int regno, unsigned int red,
                  unsigned int green, unsigned int blue,
                  unsigned int transp, struct fb_info *info)
{
    struct pmagbbfb_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 pmagbbfb_ops = {
    .owner      = THIS_MODULE,
    .fb_setcolreg   = pmagbbfb_setcolreg,
    .fb_fillrect    = cfb_fillrect,
    .fb_copyarea    = cfb_copyarea,
    .fb_imageblit   = cfb_imageblit,
};


/*
 * Turn the hardware cursor off.
 */
static void __init pmagbbfb_erase_cursor(struct fb_info *info)
{
    struct pmagbbfb_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);
}

/*
 * Set up screen parameters.
 */
static void __devinit pmagbbfb_screen_setup(struct fb_info *info)
{
    struct pmagbbfb_par *par = info->par;

    info->var.xres = ((sfb_read(par, SFB_REG_VID_HOR) >>
               SFB_VID_HOR_PIX_SHIFT) & SFB_VID_HOR_PIX_MASK) * 4;
    info->var.xres_virtual = info->var.xres;
    info->var.yres = (sfb_read(par, SFB_REG_VID_VER) >>
              SFB_VID_VER_SL_SHIFT) & SFB_VID_VER_SL_MASK;
    info->var.yres_virtual = info->var.yres;
    info->var.left_margin = ((sfb_read(par, SFB_REG_VID_HOR) >>
                  SFB_VID_HOR_BP_SHIFT) &
                 SFB_VID_HOR_BP_MASK) * 4;
    info->var.right_margin = ((sfb_read(par, SFB_REG_VID_HOR) >>
                   SFB_VID_HOR_FP_SHIFT) &
                  SFB_VID_HOR_FP_MASK) * 4;
    info->var.upper_margin = (sfb_read(par, SFB_REG_VID_VER) >>
                  SFB_VID_VER_BP_SHIFT) & SFB_VID_VER_BP_MASK;
    info->var.lower_margin = (sfb_read(par, SFB_REG_VID_VER) >>
                  SFB_VID_VER_FP_SHIFT) & SFB_VID_VER_FP_MASK;
    info->var.hsync_len = ((sfb_read(par, SFB_REG_VID_HOR) >>
                SFB_VID_HOR_SYN_SHIFT) &
                   SFB_VID_HOR_SYN_MASK) * 4;
    info->var.vsync_len = (sfb_read(par, SFB_REG_VID_VER) >>
                   SFB_VID_VER_SYN_SHIFT) & SFB_VID_VER_SYN_MASK;

    info->fix.line_length = info->var.xres;
};

/*
 * Determine oscillator configuration.
 */
static void __devinit pmagbbfb_osc_setup(struct fb_info *info)
{
    static unsigned int pmagbbfb_freqs[] __devinitdata = {
        130808, 119843, 104000, 92980, 74370, 72800,
        69197, 66000, 65000, 50350, 36000, 32000, 25175
    };
    struct pmagbbfb_par *par = info->par;
    struct tc_bus *tbus = to_tc_dev(info->device)->bus;
    u32 count0 = 8, count1 = 8, counttc = 16 * 256 + 8;
    u32 freq0, freq1, freqtc = tc_get_speed(tbus) / 250;
    int i, j;

    gp0_write(par, 0);              /* select Osc0 */
    for (j = 0; j < 16; j++) {
        mb();
        sfb_write(par, SFB_REG_TCCLK_COUNT, 0);
        mb();
        for (i = 0; i < 100; i++) { /* nominally max. 20.5us */
            if (sfb_read(par, SFB_REG_TCCLK_COUNT) == 0)
                break;
            udelay(1);
        }
        count0 += sfb_read(par, SFB_REG_VIDCLK_COUNT);
    }

    gp0_write(par, 1);              /* select Osc1 */
    for (j = 0; j < 16; j++) {
        mb();
        sfb_write(par, SFB_REG_TCCLK_COUNT, 0);

        for (i = 0; i < 100; i++) { /* nominally max. 20.5us */
            if (sfb_read(par, SFB_REG_TCCLK_COUNT) == 0)
                break;
            udelay(1);
        }
        count1 += sfb_read(par, SFB_REG_VIDCLK_COUNT);
    }

    freq0 = (freqtc * count0 + counttc / 2) / counttc;
    par->osc0 = freq0;
    if (freq0 >= pmagbbfb_freqs[0] - (pmagbbfb_freqs[0] + 32) / 64 &&
        freq0 <= pmagbbfb_freqs[0] + (pmagbbfb_freqs[0] + 32) / 64)
        par->osc0 = pmagbbfb_freqs[0];

    freq1 = (par->osc0 * count1 + count0 / 2) / count0;
    par->osc1 = freq1;
    for (i = 0; i < ARRAY_SIZE(pmagbbfb_freqs); i++)
        if (freq1 >= pmagbbfb_freqs[i] -
                 (pmagbbfb_freqs[i] + 128) / 256 &&
            freq1 <= pmagbbfb_freqs[i] +
                 (pmagbbfb_freqs[i] + 128) / 256) {
            par->osc1 = pmagbbfb_freqs[i];
            break;
        }

    if (par->osc0 - par->osc1 <= (par->osc0 + par->osc1 + 256) / 512 ||
        par->osc1 - par->osc0 <= (par->osc0 + par->osc1 + 256) / 512)
        par->osc1 = 0;

    gp0_write(par, par->osc1 != 0);         /* reselect OscX */

    info->var.pixclock = par->osc1 ?
                 (1000000000 + par->osc1 / 2) / par->osc1 :
                 (1000000000 + par->osc0 / 2) / par->osc0;
};


static int __devinit pmagbbfb_probe(struct device *dev)
{
    struct tc_dev *tdev = to_tc_dev(dev);
    resource_size_t start, len;
    struct fb_info *info;
    struct pmagbbfb_par *par;
    char freq0[12], freq1[12];
    u32 vid_base;
    int err;

    info = framebuffer_alloc(sizeof(struct pmagbbfb_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 = &pmagbbfb_ops;
    info->fix = pmagbbfb_fix;
    info->var = pmagbbfb_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->sfb = par->mmio + PMAGB_B_SFB;
    par->dac = par->mmio + PMAGB_B_BT459;

    /* Frame buffer mapping setup.  */
    info->fix.smem_start = start + PMAGB_B_FBMEM;
    par->smem = ioremap_nocache(info->fix.smem_start, info->fix.smem_len);
    if (!par->smem) {
        printk(KERN_ERR "%s: Cannot map FB\n", dev_name(dev));
        err = -ENOMEM;
        goto err_mmio_map;
    }
    vid_base = sfb_read(par, SFB_REG_VID_BASE);
    info->screen_base = (void __iomem *)par->smem + vid_base * 0x1000;
    info->screen_size = info->fix.smem_len - 2 * vid_base * 0x1000;

    pmagbbfb_erase_cursor(info);
    pmagbbfb_screen_setup(info);
    pmagbbfb_osc_setup(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);

    snprintf(freq0, sizeof(freq0), "%u.%03uMHz",
         par->osc0 / 1000, par->osc0 % 1000);
    snprintf(freq1, sizeof(freq1), "%u.%03uMHz",
         par->osc1 / 1000, par->osc1 % 1000);

    pr_info("fb%d: %s frame buffer device at %s\n",
        info->node, info->fix.id, dev_name(dev));
    pr_info("fb%d: Osc0: %s, Osc1: %s, Osc%u selected\n",
        info->node, freq0, par->osc1 ? freq1 : "disabled",
        par->osc1 != 0);

    return 0;


err_smem_map:
    iounmap(par->smem);

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 pmagbbfb_remove(struct device *dev)
{
    struct tc_dev *tdev = to_tc_dev(dev);
    struct fb_info *info = dev_get_drvdata(dev);
    struct pmagbbfb_par *par = info->par;
    resource_size_t start, len;

    put_device(dev);
    unregister_framebuffer(info);
    iounmap(par->smem);
    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 pmagbbfb_tc_table[] = {
    { "DEC     ", "PMAGB-BA" },
    { }
};
MODULE_DEVICE_TABLE(tc, pmagbbfb_tc_table);

static struct tc_driver pmagbbfb_driver = {
    .id_table   = pmagbbfb_tc_table,
    .driver     = {
        .name   = "pmagbbfb",
        .bus    = &tc_bus_type,
        .probe  = pmagbbfb_probe,
        .remove = __exit_p(pmagbbfb_remove),
    },
};

static int __init pmagbbfb_init(void)
{
#ifndef MODULE
    if (fb_get_options("pmagbbfb", NULL))
        return -ENXIO;
#endif
    return tc_register_driver(&pmagbbfb_driver);
}

static void __exit pmagbbfb_exit(void)
{
    tc_unregister_driver(&pmagbbfb_driver);
}


module_init(pmagbbfb_init);
module_exit(pmagbbfb_exit);

MODULE_LICENSE("GPL");