wm8505fb.c

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/*
 *  WonderMedia WM8505 Frame Buffer device driver
 *
 *  Copyright (C) 2010 Ed Spiridonov <[email protected]>
 *    Based on vt8500lcdfb.c
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * 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.
 */

#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/delay.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/dma-mapping.h>
#include <linux/platform_device.h>
#include <linux/wait.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/memblock.h>

#include <linux/platform_data/video-vt8500lcdfb.h>

#include "wm8505fb_regs.h"
#include "wmt_ge_rops.h"

#define DRIVER_NAME "wm8505-fb"

#define to_wm8505fb_info(__info) container_of(__info, \
                        struct wm8505fb_info, fb)
struct wm8505fb_info {
    struct fb_info      fb;
    void __iomem        *regbase;
    unsigned int        contrast;
};


static int wm8505fb_init_hw(struct fb_info *info)
{
    struct wm8505fb_info *fbi = to_wm8505fb_info(info);

    int i;

    /* I know the purpose only of few registers, so clear unknown */
    for (i = 0; i < 0x200; i += 4)
        writel(0, fbi->regbase + i);

    /* Set frame buffer address */
    writel(fbi->fb.fix.smem_start, fbi->regbase + WMT_GOVR_FBADDR);
    writel(fbi->fb.fix.smem_start, fbi->regbase + WMT_GOVR_FBADDR1);

    /*
     * Set in-memory picture format to RGB
     * 0x31C sets the correct color mode (RGB565) for WM8650
     * Bit 8+9 (0x300) are ignored on WM8505 as reserved
     */
    writel(0x31c,              fbi->regbase + WMT_GOVR_COLORSPACE);
    writel(1,              fbi->regbase + WMT_GOVR_COLORSPACE1);

    /* Virtual buffer size */
    writel(info->var.xres,         fbi->regbase + WMT_GOVR_XRES);
    writel(info->var.xres_virtual, fbi->regbase + WMT_GOVR_XRES_VIRTUAL);

    /* black magic ;) */
    writel(0xf,            fbi->regbase + WMT_GOVR_FHI);
    writel(4,              fbi->regbase + WMT_GOVR_DVO_SET);
    writel(1,              fbi->regbase + WMT_GOVR_MIF_ENABLE);
    writel(1,              fbi->regbase + WMT_GOVR_REG_UPDATE);

    return 0;
}

static int wm8505fb_set_timing(struct fb_info *info)
{
    struct wm8505fb_info *fbi = to_wm8505fb_info(info);

    int h_start = info->var.left_margin;
    int h_end = h_start + info->var.xres;
    int h_all = h_end + info->var.right_margin;
    int h_sync = info->var.hsync_len;

    int v_start = info->var.upper_margin;
    int v_end = v_start + info->var.yres;
    int v_all = v_end + info->var.lower_margin;
    int v_sync = info->var.vsync_len;

    writel(0, fbi->regbase + WMT_GOVR_TG);

    writel(h_start, fbi->regbase + WMT_GOVR_TIMING_H_START);
    writel(h_end,   fbi->regbase + WMT_GOVR_TIMING_H_END);
    writel(h_all,   fbi->regbase + WMT_GOVR_TIMING_H_ALL);
    writel(h_sync,  fbi->regbase + WMT_GOVR_TIMING_H_SYNC);

    writel(v_start, fbi->regbase + WMT_GOVR_TIMING_V_START);
    writel(v_end,   fbi->regbase + WMT_GOVR_TIMING_V_END);
    writel(v_all,   fbi->regbase + WMT_GOVR_TIMING_V_ALL);
    writel(v_sync,  fbi->regbase + WMT_GOVR_TIMING_V_SYNC);

    writel(1, fbi->regbase + WMT_GOVR_TG);

    return 0;
}


static int wm8505fb_set_par(struct fb_info *info)
{
    struct wm8505fb_info *fbi = to_wm8505fb_info(info);

    if (!fbi)
        return -EINVAL;

    if (info->var.bits_per_pixel == 32) {
        info->var.red.offset = 16;
        info->var.red.length = 8;
        info->var.red.msb_right = 0;
        info->var.green.offset = 8;
        info->var.green.length = 8;
        info->var.green.msb_right = 0;
        info->var.blue.offset = 0;
        info->var.blue.length = 8;
        info->var.blue.msb_right = 0;
        info->fix.visual = FB_VISUAL_TRUECOLOR;
        info->fix.line_length = info->var.xres_virtual << 2;
    } else if (info->var.bits_per_pixel == 16) {
        info->var.red.offset = 11;
        info->var.red.length = 5;
        info->var.red.msb_right = 0;
        info->var.green.offset = 5;
        info->var.green.length = 6;
        info->var.green.msb_right = 0;
        info->var.blue.offset = 0;
        info->var.blue.length = 5;
        info->var.blue.msb_right = 0;
        info->fix.visual = FB_VISUAL_TRUECOLOR;
        info->fix.line_length = info->var.xres_virtual << 1;
    }

    wm8505fb_set_timing(info);

    writel(fbi->contrast<<16 | fbi->contrast<<8 | fbi->contrast,
        fbi->regbase + WMT_GOVR_CONTRAST);

    return 0;
}

static ssize_t contrast_show(struct device *dev,
                 struct device_attribute *attr, char *buf)
{
    struct fb_info *info = dev_get_drvdata(dev);
    struct wm8505fb_info *fbi = to_wm8505fb_info(info);

    return sprintf(buf, "%d\n", fbi->contrast);
}

static ssize_t contrast_store(struct device *dev,
                  struct device_attribute *attr,
                  const char *buf, size_t count)
{
    struct fb_info *info = dev_get_drvdata(dev);
    struct wm8505fb_info *fbi = to_wm8505fb_info(info);
    unsigned long tmp;

    if (strict_strtoul(buf, 10, &tmp) || (tmp > 0xff))
        return -EINVAL;
    fbi->contrast = tmp;

    wm8505fb_set_par(info);

    return count;
}

static DEVICE_ATTR(contrast, 0644, contrast_show, contrast_store);

static inline u_int chan_to_field(u_int chan, struct fb_bitfield *bf)
{
    chan &= 0xffff;
    chan >>= 16 - bf->length;
    return chan << bf->offset;
}

static int wm8505fb_setcolreg(unsigned regno, unsigned red, unsigned green,
               unsigned blue, unsigned transp,
               struct fb_info *info) {
    struct wm8505fb_info *fbi = to_wm8505fb_info(info);
    int ret = 1;
    unsigned int val;
    if (regno >= 256)
        return -EINVAL;

    if (info->var.grayscale)
        red = green = blue =
            (19595 * red + 38470 * green + 7471 * blue) >> 16;

    switch (fbi->fb.fix.visual) {
    case FB_VISUAL_TRUECOLOR:
        if (regno < 16) {
            u32 *pal = info->pseudo_palette;

            val  = chan_to_field(red, &fbi->fb.var.red);
            val |= chan_to_field(green, &fbi->fb.var.green);
            val |= chan_to_field(blue, &fbi->fb.var.blue);

            pal[regno] = val;
            ret = 0;
        }
        break;
    }

    return ret;
}

static int wm8505fb_pan_display(struct fb_var_screeninfo *var,
                struct fb_info *info)
{
    struct wm8505fb_info *fbi = to_wm8505fb_info(info);

    writel(var->xoffset, fbi->regbase + WMT_GOVR_XPAN);
    writel(var->yoffset, fbi->regbase + WMT_GOVR_YPAN);
    return 0;
}

static int wm8505fb_blank(int blank, struct fb_info *info)
{
    struct wm8505fb_info *fbi = to_wm8505fb_info(info);

    switch (blank) {
    case FB_BLANK_UNBLANK:
        wm8505fb_set_timing(info);
        break;
    default:
        writel(0,  fbi->regbase + WMT_GOVR_TIMING_V_SYNC);
        break;
    }

    return 0;
}

static struct fb_ops wm8505fb_ops = {
    .owner      = THIS_MODULE,
    .fb_set_par = wm8505fb_set_par,
    .fb_setcolreg   = wm8505fb_setcolreg,
    .fb_fillrect    = wmt_ge_fillrect,
    .fb_copyarea    = wmt_ge_copyarea,
    .fb_imageblit   = sys_imageblit,
    .fb_sync    = wmt_ge_sync,
    .fb_pan_display = wm8505fb_pan_display,
    .fb_blank   = wm8505fb_blank,
};

static int __devinit wm8505fb_probe(struct platform_device *pdev)
{
    struct wm8505fb_info    *fbi;
    struct resource     *res;
    void            *addr;
    int ret;

    struct fb_videomode of_mode;
    struct device_node  *np;
    u32         bpp;
    dma_addr_t fb_mem_phys;
    unsigned long fb_mem_len;
    void *fb_mem_virt;

    ret = -ENOMEM;
    fbi = NULL;

    fbi = devm_kzalloc(&pdev->dev, sizeof(struct wm8505fb_info) +
            sizeof(u32) * 16, GFP_KERNEL);
    if (!fbi) {
        dev_err(&pdev->dev, "Failed to initialize framebuffer device\n");
        ret = -ENOMEM;
        goto failed;
    }

    strcpy(fbi->fb.fix.id, DRIVER_NAME);

    fbi->fb.fix.type    = FB_TYPE_PACKED_PIXELS;
    fbi->fb.fix.xpanstep    = 1;
    fbi->fb.fix.ypanstep    = 1;
    fbi->fb.fix.ywrapstep   = 0;
    fbi->fb.fix.accel   = FB_ACCEL_NONE;

    fbi->fb.fbops       = &wm8505fb_ops;
    fbi->fb.flags       = FBINFO_DEFAULT
                | FBINFO_HWACCEL_COPYAREA
                | FBINFO_HWACCEL_FILLRECT
                | FBINFO_HWACCEL_XPAN
                | FBINFO_HWACCEL_YPAN
                | FBINFO_VIRTFB
                | FBINFO_PARTIAL_PAN_OK;
    fbi->fb.node        = -1;

    addr = fbi;
    addr = addr + sizeof(struct wm8505fb_info);
    fbi->fb.pseudo_palette  = addr;

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (res == NULL) {
        dev_err(&pdev->dev, "no I/O memory resource defined\n");
        ret = -ENODEV;
        goto failed_fbi;
    }

    res = request_mem_region(res->start, resource_size(res), DRIVER_NAME);
    if (res == NULL) {
        dev_err(&pdev->dev, "failed to request I/O memory\n");
        ret = -EBUSY;
        goto failed_fbi;
    }

    fbi->regbase = ioremap(res->start, resource_size(res));
    if (fbi->regbase == NULL) {
        dev_err(&pdev->dev, "failed to map I/O memory\n");
        ret = -EBUSY;
        goto failed_free_res;
    }

    np = of_parse_phandle(pdev->dev.of_node, "default-mode", 0);
    if (!np) {
        pr_err("%s: No display description in Device Tree\n", __func__);
        ret = -EINVAL;
        goto failed_free_res;
    }

    /*
     * This code is copied from Sascha Hauer's of_videomode helper
     * and can be replaced with a call to the helper once mainlined
     */
    ret = 0;
    ret |= of_property_read_u32(np, "hactive", &of_mode.xres);
    ret |= of_property_read_u32(np, "vactive", &of_mode.yres);
    ret |= of_property_read_u32(np, "hback-porch", &of_mode.left_margin);
    ret |= of_property_read_u32(np, "hfront-porch", &of_mode.right_margin);
    ret |= of_property_read_u32(np, "hsync-len", &of_mode.hsync_len);
    ret |= of_property_read_u32(np, "vback-porch", &of_mode.upper_margin);
    ret |= of_property_read_u32(np, "vfront-porch", &of_mode.lower_margin);
    ret |= of_property_read_u32(np, "vsync-len", &of_mode.vsync_len);
    ret |= of_property_read_u32(np, "bpp", &bpp);
    if (ret) {
        pr_err("%s: Unable to read display properties\n", __func__);
        goto failed_free_res;
    }

    of_mode.vmode = FB_VMODE_NONINTERLACED;
    fb_videomode_to_var(&fbi->fb.var, &of_mode);

    fbi->fb.var.nonstd      = 0;
    fbi->fb.var.activate        = FB_ACTIVATE_NOW;

    fbi->fb.var.height      = -1;
    fbi->fb.var.width       = -1;

    /* try allocating the framebuffer */
    fb_mem_len = of_mode.xres * of_mode.yres * 2 * (bpp / 8);
    fb_mem_virt = dma_alloc_coherent(&pdev->dev, fb_mem_len, &fb_mem_phys,
                GFP_KERNEL);
    if (!fb_mem_virt) {
        pr_err("%s: Failed to allocate framebuffer\n", __func__);
        return -ENOMEM;
    };

    fbi->fb.var.xres_virtual    = of_mode.xres;
    fbi->fb.var.yres_virtual    = of_mode.yres * 2;
    fbi->fb.var.bits_per_pixel  = bpp;

    fbi->fb.fix.smem_start      = fb_mem_phys;
    fbi->fb.fix.smem_len        = fb_mem_len;
    fbi->fb.screen_base     = fb_mem_virt;
    fbi->fb.screen_size     = fb_mem_len;

    if (fb_alloc_cmap(&fbi->fb.cmap, 256, 0) < 0) {
        dev_err(&pdev->dev, "Failed to allocate color map\n");
        ret = -ENOMEM;
        goto failed_free_io;
    }

    wm8505fb_init_hw(&fbi->fb);

    fbi->contrast = 0x80;
    ret = wm8505fb_set_par(&fbi->fb);
    if (ret) {
        dev_err(&pdev->dev, "Failed to set parameters\n");
        goto failed_free_cmap;
    }

    platform_set_drvdata(pdev, fbi);

    ret = register_framebuffer(&fbi->fb);
    if (ret < 0) {
        dev_err(&pdev->dev,
            "Failed to register framebuffer device: %d\n", ret);
        goto failed_free_cmap;
    }

    ret = device_create_file(&pdev->dev, &dev_attr_contrast);
    if (ret < 0) {
        printk(KERN_WARNING "fb%d: failed to register attributes (%d)\n",
            fbi->fb.node, ret);
    }

    printk(KERN_INFO "fb%d: %s frame buffer at 0x%lx-0x%lx\n",
           fbi->fb.node, fbi->fb.fix.id, fbi->fb.fix.smem_start,
           fbi->fb.fix.smem_start + fbi->fb.fix.smem_len - 1);

    return 0;

failed_free_cmap:
    if (fbi->fb.cmap.len)
        fb_dealloc_cmap(&fbi->fb.cmap);
failed_free_io:
    iounmap(fbi->regbase);
failed_free_res:
    release_mem_region(res->start, resource_size(res));
failed_fbi:
    platform_set_drvdata(pdev, NULL);
    kfree(fbi);
failed:
    return ret;
}

static int __devexit wm8505fb_remove(struct platform_device *pdev)
{
    struct wm8505fb_info *fbi = platform_get_drvdata(pdev);
    struct resource *res;

    device_remove_file(&pdev->dev, &dev_attr_contrast);

    unregister_framebuffer(&fbi->fb);

    writel(0, fbi->regbase);

    if (fbi->fb.cmap.len)
        fb_dealloc_cmap(&fbi->fb.cmap);

    iounmap(fbi->regbase);

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    release_mem_region(res->start, resource_size(res));

    kfree(fbi);

    return 0;
}

static const struct of_device_id wmt_dt_ids[] = {
    { .compatible = "wm,wm8505-fb", },
    {}
};

static struct platform_driver wm8505fb_driver = {
    .probe      = wm8505fb_probe,
    .remove     = __devexit_p(wm8505fb_remove),
    .driver     = {
        .owner  = THIS_MODULE,
        .name   = DRIVER_NAME,
        .of_match_table = of_match_ptr(wmt_dt_ids),
    },
};

module_platform_driver(wm8505fb_driver);

MODULE_AUTHOR("Ed Spiridonov <[email protected]>");
MODULE_DESCRIPTION("Framebuffer driver for WMT WM8505");
MODULE_LICENSE("GPL v2");
MODULE_DEVICE_TABLE(of, wmt_dt_ids);