clps711xfb.c

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/*
 *  linux/drivers/video/clps711xfb.c
 *
 *  Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *  Framebuffer driver for the CLPS7111 and EP7212 processors.
 */
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/delay.h>

#include <mach/hardware.h>
#include <asm/mach-types.h>
#include <linux/uaccess.h>

#include <mach/syspld.h>

struct fb_info  *cfb;

#define CMAP_MAX_SIZE   16

/*
 * LCD AC Prescale.  This comes from the LCD panel manufacturers specifications.
 * This determines how many clocks + 1 of CL1 before the M signal toggles.
 * The number of lines on the display must not be divisible by this number.
 */
static unsigned int lcd_ac_prescale = 13;

/*
 *    Set a single color register. Return != 0 for invalid regno.
 */
static int
clps7111fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
             u_int transp, struct fb_info *info)
{
    unsigned int level, mask, shift, pal;

    if (regno >= (1 << info->var.bits_per_pixel))
        return 1;

    /* gray = 0.30*R + 0.58*G + 0.11*B */
    level = (red * 77 + green * 151 + blue * 28) >> 20;

    /*
     * On an LCD, a high value is dark, while a low value is light. 
     * So we invert the level.
     *
     * This isn't true on all machines, so we only do it on EDB7211.
     *  --rmk
     */
    if (machine_is_edb7211()) {
        level = 15 - level;
    }

    shift = 4 * (regno & 7);
    level <<= shift;
    mask  = 15 << shift;
    level &= mask;

    regno = regno < 8 ? PALLSW : PALMSW;

    pal = clps_readl(regno);
    pal = (pal & ~mask) | level;
    clps_writel(pal, regno);

    return 0;
}

/*
 * Validate the purposed mode.
 */ 
static int
clps7111fb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
    var->transp.msb_right   = 0;
    var->transp.offset  = 0;
    var->transp.length  = 0;
    var->red.msb_right  = 0;
    var->red.offset     = 0;
    var->red.length     = var->bits_per_pixel;
    var->green      = var->red;
    var->blue       = var->red;

    if (var->bits_per_pixel > 4) 
        return -EINVAL;

    return 0;
}

/*
 * Set the hardware state.
 */ 
static int 
clps7111fb_set_par(struct fb_info *info)
{
    unsigned int lcdcon, syscon, pixclock;

    switch (info->var.bits_per_pixel) {
    case 1:
        info->fix.visual = FB_VISUAL_MONO01;
        break;
    case 2:
        info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
        break;
    case 4:
        info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
        break;
    }

    info->fix.line_length = info->var.xres_virtual * info->var.bits_per_pixel / 8;

    lcdcon = (info->var.xres_virtual * info->var.yres_virtual * info->var.bits_per_pixel) / 128 - 1;
    lcdcon |= ((info->var.xres_virtual / 16) - 1) << 13;
    lcdcon |= lcd_ac_prescale << 25;

    /*
     * Calculate pixel prescale value from the pixclock.  This is:
     *  36.864MHz / pixclock_mhz - 1.
     * However, pixclock is in picoseconds, so this ends up being:
     *  36864000 * pixclock_ps / 10^12 - 1
     * and this will overflow the 32-bit math.  We perform this as
     * (9 * 4096000 == 36864000):
     *  pixclock_ps * 9 * (4096000 / 10^12) - 1
     */
    pixclock = 9 * info->var.pixclock / 244140 - 1;
    lcdcon |= pixclock << 19;

    if (info->var.bits_per_pixel == 4)
        lcdcon |= LCDCON_GSMD;
    if (info->var.bits_per_pixel >= 2)
        lcdcon |= LCDCON_GSEN;

    /*
     * LCDCON must only be changed while the LCD is disabled
     */
    syscon = clps_readl(SYSCON1);
    clps_writel(syscon & ~SYSCON1_LCDEN, SYSCON1);
    clps_writel(lcdcon, LCDCON);
    clps_writel(syscon | SYSCON1_LCDEN, SYSCON1);
    return 0;
}

static int clps7111fb_blank(int blank, struct fb_info *info)
{
        if (blank) {
        if (machine_is_edb7211()) {
            /* Turn off the LCD backlight. */
            clps_writeb(clps_readb(PDDR) & ~EDB_PD3_LCDBL, PDDR);

            /* Power off the LCD DC-DC converter. */
            clps_writeb(clps_readb(PDDR) & ~EDB_PD1_LCD_DC_DC_EN, PDDR);

            /* Delay for a little while (half a second). */
            udelay(100);

            /* Power off the LCD panel. */
            clps_writeb(clps_readb(PDDR) & ~EDB_PD2_LCDEN, PDDR);

            /* Power off the LCD controller. */
            clps_writel(clps_readl(SYSCON1) & ~SYSCON1_LCDEN, 
                    SYSCON1);
        }
    } else {
        if (machine_is_edb7211()) {
            /* Power up the LCD controller. */
            clps_writel(clps_readl(SYSCON1) | SYSCON1_LCDEN,
                    SYSCON1);

            /* Power up the LCD panel. */
            clps_writeb(clps_readb(PDDR) | EDB_PD2_LCDEN, PDDR);

            /* Delay for a little while. */
            udelay(100);

            /* Power up the LCD DC-DC converter. */
            clps_writeb(clps_readb(PDDR) | EDB_PD1_LCD_DC_DC_EN,
                    PDDR);

            /* Turn on the LCD backlight. */
            clps_writeb(clps_readb(PDDR) | EDB_PD3_LCDBL, PDDR);
        }
    }
    return 0;
}

static struct fb_ops clps7111fb_ops = {
    .owner      = THIS_MODULE,
    .fb_check_var   = clps7111fb_check_var,
    .fb_set_par = clps7111fb_set_par,
    .fb_setcolreg   = clps7111fb_setcolreg,
    .fb_blank   = clps7111fb_blank,
    .fb_fillrect    = cfb_fillrect,
    .fb_copyarea    = cfb_copyarea,
    .fb_imageblit   = cfb_imageblit,
};

static int backlight_proc_show(struct seq_file *m, void *v)
{
    if (machine_is_edb7211()) {
        seq_printf(m, "%d\n",
                (clps_readb(PDDR) & EDB_PD3_LCDBL) ? 1 : 0);
    }

    return 0;
}

static int backlight_proc_open(struct inode *inode, struct file *file)
{
    return single_open(file, backlight_proc_show, NULL);
}

static ssize_t backlight_proc_write(struct file *file, const char *buffer,
                    size_t count, loff_t *pos)
{
    unsigned char char_value;
    int value;

    if (count < 1) {
        return -EINVAL;
    }

    if (copy_from_user(&char_value, buffer, 1)) 
        return -EFAULT;

    value = char_value - '0';

    if (machine_is_edb7211()) {
        unsigned char port_d;

        port_d = clps_readb(PDDR);

        if (value) {
            port_d |= EDB_PD3_LCDBL;
        } else {
            port_d &= ~EDB_PD3_LCDBL;
        }

        clps_writeb(port_d, PDDR);
    }

    return count;
}

static const struct file_operations backlight_proc_fops = {
    .owner      = THIS_MODULE,
    .open       = backlight_proc_open,
    .read       = seq_read,
    .llseek     = seq_lseek,
    .release    = single_release,
    .write      = backlight_proc_write,
};

static void __init clps711x_guess_lcd_params(struct fb_info *info)
{
    unsigned int lcdcon, syscon, size;
    unsigned long phys_base = PAGE_OFFSET;
    void *virt_base = (void *)PAGE_OFFSET;

    info->var.xres_virtual   = 640;
    info->var.yres_virtual   = 240;
    info->var.bits_per_pixel = 4;
    info->var.activate   = FB_ACTIVATE_NOW;
    info->var.height     = -1;
    info->var.width      = -1;
    info->var.pixclock   = 93006; /* 10.752MHz pixel clock */

    /*
     * If the LCD controller is already running, decode the values
     * in LCDCON to xres/yres/bpp/pixclock/acprescale
     */
    syscon = clps_readl(SYSCON1);
    if (syscon & SYSCON1_LCDEN) {
        lcdcon = clps_readl(LCDCON);

        /*
         * Decode GSMD and GSEN bits to bits per pixel
         */
        switch (lcdcon & (LCDCON_GSMD | LCDCON_GSEN)) {
        case LCDCON_GSMD | LCDCON_GSEN:
            info->var.bits_per_pixel = 4;
            break;

        case LCDCON_GSEN:
            info->var.bits_per_pixel = 2;
            break;

        default:
            info->var.bits_per_pixel = 1;
            break;
        }

        /*
         * Decode xres/yres
         */
        info->var.xres_virtual = (((lcdcon >> 13) & 0x3f) + 1) * 16;
        info->var.yres_virtual = (((lcdcon & 0x1fff) + 1) * 128) /
                      (info->var.xres_virtual *
                       info->var.bits_per_pixel);

        /*
         * Calculate pixclock
         */
        info->var.pixclock = (((lcdcon >> 19) & 0x3f) + 1) * 244140 / 9;

        /*
         * Grab AC prescale
         */
        lcd_ac_prescale = (lcdcon >> 25) & 0x1f;
    }

    info->var.xres = info->var.xres_virtual;
    info->var.yres = info->var.yres_virtual;
    info->var.grayscale = info->var.bits_per_pixel > 1;

    size = info->var.xres * info->var.yres * info->var.bits_per_pixel / 8;

    /*
     * Might be worth checking to see if we can use the on-board
     * RAM if size here...
     * CLPS7110 - no on-board SRAM
     * EP7212   - 38400 bytes
     */
    if (size <= 38400) {
        printk(KERN_INFO "CLPS711xFB: could use on-board SRAM?\n");
    }

    if ((syscon & SYSCON1_LCDEN) == 0) {
        /*
         * The display isn't running.  Ensure that
         * the display memory is empty.
         */
        memset(virt_base, 0, size);
    }

    info->screen_base    = virt_base;
    info->fix.smem_start = phys_base;
    info->fix.smem_len   = PAGE_ALIGN(size);
    info->fix.type       = FB_TYPE_PACKED_PIXELS;
}

int __init clps711xfb_init(void)
{
    int err = -ENOMEM;

    if (fb_get_options("clps711xfb", NULL))
        return -ENODEV;

    cfb = kzalloc(sizeof(*cfb), GFP_KERNEL);
    if (!cfb)
        goto out;

    strcpy(cfb->fix.id, "clps711x");

    cfb->fbops      = &clps7111fb_ops;
    cfb->flags      = FBINFO_DEFAULT;

    clps711x_guess_lcd_params(cfb);

    fb_alloc_cmap(&cfb->cmap, CMAP_MAX_SIZE, 0);

    if (!proc_create("backlight", 0444, NULL, &backlight_proc_fops)) {
        printk("Couldn't create the /proc entry for the backlight.\n");
        return -EINVAL;
    }

    /*
     * Power up the LCD
     */
    if (machine_is_p720t()) {
        PLD_LCDEN = PLD_LCDEN_EN;
        PLD_PWR |= (PLD_S4_ON|PLD_S3_ON|PLD_S2_ON|PLD_S1_ON);
    }

    if (machine_is_edb7211()) {
        /* Power up the LCD panel. */
        clps_writeb(clps_readb(PDDR) | EDB_PD2_LCDEN, PDDR);

        /* Delay for a little while. */
        udelay(100);

        /* Power up the LCD DC-DC converter. */
        clps_writeb(clps_readb(PDDR) | EDB_PD1_LCD_DC_DC_EN, PDDR);

        /* Turn on the LCD backlight. */
        clps_writeb(clps_readb(PDDR) | EDB_PD3_LCDBL, PDDR);
    }

    err = register_framebuffer(cfb);

out:    return err;
}

static void __exit clps711xfb_exit(void)
{
    unregister_framebuffer(cfb);
    kfree(cfb);

    /*
     * Power down the LCD
     */
    if (machine_is_p720t()) {
        PLD_LCDEN = 0;
        PLD_PWR &= ~(PLD_S4_ON|PLD_S3_ON|PLD_S2_ON|PLD_S1_ON);
    }
}

module_init(clps711xfb_init);
module_exit(clps711xfb_exit);

MODULE_AUTHOR("Russell King <[email protected]>");
MODULE_DESCRIPTION("CLPS711x framebuffer driver");
MODULE_LICENSE("GPL");