fbdev: framebuffer support for HTC Dream

Add a framebuffer driver for Qualcomm MSM/QSD SoCs, tested on HTC Dream
smartphone (aka T-Mobile G1, aka ADP1).

Brian said:

  I did the original quick and dirty version for bringup.  Rebecca took
  over and (re)wrote the bulk of the driver, getting things stable for
  production ship of Dream and Sapphire, and Dima is currently adding
  support for later Qualcomm chipsets (QSD8x50, etc).

Signed-off-by: Pavel Machek <pavel@ucw.cz>
Cc: Brian Swetland <swetland@google.com>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: Rebecca Schultz Zavin <rebecca@android.com>
Cc: Dima Zavin <dima@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 636 insertions, 0 deletions

diff --git a/drivers/video/msm/msm_fb.c b/drivers/video/msm/msm_fb.c
new file mode 100644
index 000000000000..49101dda45ee
--- /dev/null
+++ b/drivers/video/msm/msm_fb.c
@@ -0,0 +1,636 @@
+/* drivers/video/msm/msm_fb.c
+ *
+ * Core MSM framebuffer driver.
+ *
+ * Copyright (C) 2007 Google Incorporated
+ *
+ * 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/platform_device.h>
+#include <linux/module.h>
+#include <linux/fb.h>
+#include <linux/delay.h>
+
+#include <linux/freezer.h>
+#include <linux/wait.h>
+#include <linux/msm_mdp.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <mach/msm_fb.h>
+#include <mach/board.h>
+#include <linux/workqueue.h>
+#include <linux/clk.h>
+#include <linux/debugfs.h>
+#include <linux/dma-mapping.h>
+
+#define PRINT_FPS 0
+#define PRINT_BLIT_TIME 0
+
+#define SLEEPING 0x4
+#define UPDATING 0x3
+#define FULL_UPDATE_DONE 0x2
+#define WAKING 0x1
+#define AWAKE 0x0
+
+#define NONE 0
+#define SUSPEND_RESUME 0x1
+#define FPS 0x2
+#define BLIT_TIME 0x4
+#define SHOW_UPDATES 0x8
+
+#define DLOG(mask, fmt, args...) \
+do { \
+        if (msmfb_debug_mask & mask) \
+                printk(KERN_INFO "msmfb: "fmt, ##args); \
+} while (0)
+
+static int msmfb_debug_mask;
+module_param_named(msmfb_debug_mask, msmfb_debug_mask, int,
+                   S_IRUGO | S_IWUSR | S_IWGRP);
+
+struct mdp_device *mdp;
+
+struct msmfb_info {
+        struct fb_info *fb;
+        struct msm_panel_data *panel;
+        int xres;
+        int yres;
+        unsigned output_format;
+        unsigned yoffset;
+        unsigned frame_requested;
+        unsigned frame_done;
+        int sleeping;
+        unsigned update_frame;
+        struct {
+                int left;
+                int top;
+                int eright; /* exclusive */
+                int ebottom; /* exclusive */
+        } update_info;
+        char *black;
+
+        spinlock_t update_lock;
+        struct mutex panel_init_lock;
+        wait_queue_head_t frame_wq;
+        struct workqueue_struct *resume_workqueue;
+        struct work_struct resume_work;
+        struct msmfb_callback dma_callback;
+        struct msmfb_callback vsync_callback;
+        struct hrtimer fake_vsync;
+        ktime_t vsync_request_time;
+};
+
+static int msmfb_open(struct fb_info *info, int user)
+{
+        return 0;
+}
+
+static int msmfb_release(struct fb_info *info, int user)
+{
+        return 0;
+}
+
+/* Called from dma interrupt handler, must not sleep */
+static void msmfb_handle_dma_interrupt(struct msmfb_callback *callback)
+{
+        unsigned long irq_flags;
+        struct msmfb_info *msmfb  = container_of(callback, struct msmfb_info,
+                                               dma_callback);
+
+        spin_lock_irqsave(&msmfb->update_lock, irq_flags);
+        msmfb->frame_done = msmfb->frame_requested;
+        if (msmfb->sleeping == UPDATING &&
+            msmfb->frame_done == msmfb->update_frame) {
+                DLOG(SUSPEND_RESUME, "full update completed\n");
+                queue_work(msmfb->resume_workqueue, &msmfb->resume_work);
+        }
+        spin_unlock_irqrestore(&msmfb->update_lock, irq_flags);
+        wake_up(&msmfb->frame_wq);
+}
+
+static int msmfb_start_dma(struct msmfb_info *msmfb)
+{
+        uint32_t x, y, w, h;
+        unsigned addr;
+        unsigned long irq_flags;
+        uint32_t yoffset;
+        s64 time_since_request;
+        struct msm_panel_data *panel = msmfb->panel;
+
+        spin_lock_irqsave(&msmfb->update_lock, irq_flags);
+        time_since_request = ktime_to_ns(ktime_sub(ktime_get(),
+                             msmfb->vsync_request_time));
+        if (time_since_request > 20 * NSEC_PER_MSEC) {
+                uint32_t us;
+                us = do_div(time_since_request, NSEC_PER_MSEC) / NSEC_PER_USEC;
+                printk(KERN_WARNING "msmfb_start_dma %lld.%03u ms after vsync "
+                        "request\n", time_since_request, us);
+        }
+        if (msmfb->frame_done == msmfb->frame_requested) {
+                spin_unlock_irqrestore(&msmfb->update_lock, irq_flags);
+                return -1;
+        }
+        if (msmfb->sleeping == SLEEPING) {
+                DLOG(SUSPEND_RESUME, "tried to start dma while asleep\n");
+                spin_unlock_irqrestore(&msmfb->update_lock, irq_flags);
+                return -1;
+        }
+        x = msmfb->update_info.left;
+        y = msmfb->update_info.top;
+        w = msmfb->update_info.eright - x;
+        h = msmfb->update_info.ebottom - y;
+        yoffset = msmfb->yoffset;
+        msmfb->update_info.left = msmfb->xres + 1;
+        msmfb->update_info.top = msmfb->yres + 1;
+        msmfb->update_info.eright = 0;
+        msmfb->update_info.ebottom = 0;
+        if (unlikely(w > msmfb->xres || h > msmfb->yres ||
+                     w == 0 || h == 0)) {
+                printk(KERN_INFO "invalid update: %d %d %d "
+                                "%d\n", x, y, w, h);
+                msmfb->frame_done = msmfb->frame_requested;
+                goto error;
+        }
+        spin_unlock_irqrestore(&msmfb->update_lock, irq_flags);
+
+        addr = ((msmfb->xres * (yoffset + y) + x) * 2);
+        mdp->dma(mdp, addr + msmfb->fb->fix.smem_start,
+                 msmfb->xres * 2, w, h, x, y, &msmfb->dma_callback,
+                 panel->interface_type);
+        return 0;
+error:
+        spin_unlock_irqrestore(&msmfb->update_lock, irq_flags);
+        /* some clients need to clear their vsync interrupt */
+        if (panel->clear_vsync)
+                panel->clear_vsync(panel);
+        wake_up(&msmfb->frame_wq);
+        return 0;
+}
+
+/* Called from esync interrupt handler, must not sleep */
+static void msmfb_handle_vsync_interrupt(struct msmfb_callback *callback)
+{
+        struct msmfb_info *msmfb = container_of(callback, struct msmfb_info,
+                                               vsync_callback);
+        msmfb_start_dma(msmfb);
+}
+
+static enum hrtimer_restart msmfb_fake_vsync(struct hrtimer *timer)
+{
+        struct msmfb_info *msmfb  = container_of(timer, struct msmfb_info,
+                                               fake_vsync);
+        msmfb_start_dma(msmfb);
+        return HRTIMER_NORESTART;
+}
+
+static void msmfb_pan_update(struct fb_info *info, uint32_t left, uint32_t top,
+                             uint32_t eright, uint32_t ebottom,
+                             uint32_t yoffset, int pan_display)
+{
+        struct msmfb_info *msmfb = info->par;
+        struct msm_panel_data *panel = msmfb->panel;
+        unsigned long irq_flags;
+        int sleeping;
+        int retry = 1;
+
+        DLOG(SHOW_UPDATES, "update %d %d %d %d %d %d\n",
+                left, top, eright, ebottom, yoffset, pan_display);
+restart:
+        spin_lock_irqsave(&msmfb->update_lock, irq_flags);
+
+        /* if we are sleeping, on a pan_display wait 10ms (to throttle back
+         * drawing otherwise return */
+        if (msmfb->sleeping == SLEEPING) {
+                DLOG(SUSPEND_RESUME, "drawing while asleep\n");
+                spin_unlock_irqrestore(&msmfb->update_lock, irq_flags);
+                if (pan_display)
+                        wait_event_interruptible_timeout(msmfb->frame_wq,
+                                msmfb->sleeping != SLEEPING, HZ/10);
+                return;
+        }
+
+        sleeping = msmfb->sleeping;
+        /* on a full update, if the last frame has not completed, wait for it */
+        if (pan_display && (msmfb->frame_requested != msmfb->frame_done ||
+                            sleeping == UPDATING)) {
+                int ret;
+                spin_unlock_irqrestore(&msmfb->update_lock, irq_flags);
+                ret = wait_event_interruptible_timeout(msmfb->frame_wq,
+                        msmfb->frame_done == msmfb->frame_requested &&
+                        msmfb->sleeping != UPDATING, 5 * HZ);
+                if (ret <= 0 && (msmfb->frame_requested != msmfb->frame_done ||
+                                 msmfb->sleeping == UPDATING)) {
+                        if (retry && panel->request_vsync &&
+                            (sleeping == AWAKE)) {
+                                panel->request_vsync(panel,
+                                        &msmfb->vsync_callback);
+                                retry = 0;
+                                printk(KERN_WARNING "msmfb_pan_display timeout "
+                                        "rerequest vsync\n");
+                        } else {
+                                printk(KERN_WARNING "msmfb_pan_display timeout "
+                                        "waiting for frame start, %d %d\n",
+                                        msmfb->frame_requested,
+                                        msmfb->frame_done);
+                                return;
+                        }
+                }
+                goto restart;
+        }
+
+
+        msmfb->frame_requested++;
+        /* if necessary, update the y offset, if this is the
+         * first full update on resume, set the sleeping state */
+        if (pan_display) {
+                msmfb->yoffset = yoffset;
+                if (left == 0 && top == 0 && eright == info->var.xres &&
+                    ebottom == info->var.yres) {
+                        if (sleeping == WAKING) {
+                                msmfb->update_frame = msmfb->frame_requested;
+                                DLOG(SUSPEND_RESUME, "full update starting\n");
+                                msmfb->sleeping = UPDATING;
+                        }
+                }
+        }
+
+        /* set the update request */
+        if (left < msmfb->update_info.left)
+                msmfb->update_info.left = left;
+        if (top < msmfb->update_info.top)
+                msmfb->update_info.top = top;
+        if (eright > msmfb->update_info.eright)
+                msmfb->update_info.eright = eright;
+        if (ebottom > msmfb->update_info.ebottom)
+                msmfb->update_info.ebottom = ebottom;
+        DLOG(SHOW_UPDATES, "update queued %d %d %d %d %d\n",
+                msmfb->update_info.left, msmfb->update_info.top,
+                msmfb->update_info.eright, msmfb->update_info.ebottom,
+                msmfb->yoffset);
+        spin_unlock_irqrestore(&msmfb->update_lock, irq_flags);
+
+        /* if the panel is all the way on wait for vsync, otherwise sleep
+         * for 16 ms (long enough for the dma to panel) and then begin dma */
+        msmfb->vsync_request_time = ktime_get();
+        if (panel->request_vsync && (sleeping == AWAKE)) {
+                panel->request_vsync(panel, &msmfb->vsync_callback);
+        } else {
+                if (!hrtimer_active(&msmfb->fake_vsync)) {
+                        hrtimer_start(&msmfb->fake_vsync,
+                                      ktime_set(0, NSEC_PER_SEC/60),
+                                      HRTIMER_MODE_REL);
+                }
+        }
+}
+
+static void msmfb_update(struct fb_info *info, uint32_t left, uint32_t top,
+                         uint32_t eright, uint32_t ebottom)
+{
+        msmfb_pan_update(info, left, top, eright, ebottom, 0, 0);
+}
+
+static void power_on_panel(struct work_struct *work)
+{
+        struct msmfb_info *msmfb =
+                container_of(work, struct msmfb_info, resume_work);
+        struct msm_panel_data *panel = msmfb->panel;
+        unsigned long irq_flags;
+
+        mutex_lock(&msmfb->panel_init_lock);
+        DLOG(SUSPEND_RESUME, "turning on panel\n");
+        if (msmfb->sleeping == UPDATING) {
+                if (panel->unblank(panel)) {
+                        printk(KERN_INFO "msmfb: panel unblank failed,"
+                               "not starting drawing\n");
+                        goto error;
+                }
+                spin_lock_irqsave(&msmfb->update_lock, irq_flags);
+                msmfb->sleeping = AWAKE;
+                wake_up(&msmfb->frame_wq);
+                spin_unlock_irqrestore(&msmfb->update_lock, irq_flags);
+        }
+error:
+        mutex_unlock(&msmfb->panel_init_lock);
+}
+
+
+static int msmfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
+{
+        if ((var->xres != info->var.xres) ||
+            (var->yres != info->var.yres) ||
+            (var->xres_virtual != info->var.xres_virtual) ||
+            (var->yres_virtual != info->var.yres_virtual) ||
+            (var->xoffset != info->var.xoffset) ||
+            (var->bits_per_pixel != info->var.bits_per_pixel) ||
+            (var->grayscale != info->var.grayscale))
+                 return -EINVAL;
+        return 0;
+}
+
+int msmfb_pan_display(struct fb_var_screeninfo *var, struct fb_info *info)
+{
+        struct msmfb_info *msmfb = info->par;
+        struct msm_panel_data *panel = msmfb->panel;
+
+        /* "UPDT" */
+        if ((panel->caps & MSMFB_CAP_PARTIAL_UPDATES) &&
+            (var->reserved[0] == 0x54445055)) {
+                msmfb_pan_update(info, var->reserved[1] & 0xffff,
+                                 var->reserved[1] >> 16,
+                                 var->reserved[2] & 0xffff,
+                                 var->reserved[2] >> 16, var->yoffset, 1);
+        } else {
+                msmfb_pan_update(info, 0, 0, info->var.xres, info->var.yres,
+                                 var->yoffset, 1);
+        }
+        return 0;
+}
+
+static void msmfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
+{
+        cfb_fillrect(p, rect);
+        msmfb_update(p, rect->dx, rect->dy, rect->dx + rect->width,
+                     rect->dy + rect->height);
+}
+
+static void msmfb_copyarea(struct fb_info *p, const struct fb_copyarea *area)
+{
+        cfb_copyarea(p, area);
+        msmfb_update(p, area->dx, area->dy, area->dx + area->width,
+                     area->dy + area->height);
+}
+
+static void msmfb_imageblit(struct fb_info *p, const struct fb_image *image)
+{
+        cfb_imageblit(p, image);
+        msmfb_update(p, image->dx, image->dy, image->dx + image->width,
+                     image->dy + image->height);
+}
+
+
+static int msmfb_blit(struct fb_info *info,
+                      void __user *p)
+{
+        struct mdp_blit_req req;
+        struct mdp_blit_req_list req_list;
+        int i;
+        int ret;
+
+        if (copy_from_user(&req_list, p, sizeof(req_list)))
+                return -EFAULT;
+
+        for (i = 0; i < req_list.count; i++) {
+                struct mdp_blit_req_list *list =
+                        (struct mdp_blit_req_list *)p;
+                if (copy_from_user(&req, &list->req[i], sizeof(req)))
+                        return -EFAULT;
+                ret = mdp->blit(mdp, info, &req);
+                if (ret)
+                        return ret;
+        }
+        return 0;
+}
+
+
+DEFINE_MUTEX(mdp_ppp_lock);
+
+static int msmfb_ioctl(struct fb_info *p, unsigned int cmd, unsigned long arg)
+{
+        void __user *argp = (void __user *)arg;
+        int ret;
+
+        switch (cmd) {
+        case MSMFB_GRP_DISP:
+                mdp->set_grp_disp(mdp, arg);
+                break;
+        case MSMFB_BLIT:
+                ret = msmfb_blit(p, argp);
+                if (ret)
+                        return ret;
+                break;
+        default:
+                        printk(KERN_INFO "msmfb unknown ioctl: %d\n", cmd);
+                        return -EINVAL;
+        }
+        return 0;
+}
+
+static struct fb_ops msmfb_ops = {
+        .owner = THIS_MODULE,
+        .fb_open = msmfb_open,
+        .fb_release = msmfb_release,
+        .fb_check_var = msmfb_check_var,
+        .fb_pan_display = msmfb_pan_display,
+        .fb_fillrect = msmfb_fillrect,
+        .fb_copyarea = msmfb_copyarea,
+        .fb_imageblit = msmfb_imageblit,
+        .fb_ioctl = msmfb_ioctl,
+};
+
+static unsigned PP[16];
+
+
+
+#define BITS_PER_PIXEL 16
+
+static void setup_fb_info(struct msmfb_info *msmfb)
+{
+        struct fb_info *fb_info = msmfb->fb;
+        int r;
+
+        /* finish setting up the fb_info struct */
+        strncpy(fb_info->fix.id, "msmfb", 16);
+        fb_info->fix.ypanstep = 1;
+
+        fb_info->fbops = &msmfb_ops;
+        fb_info->flags = FBINFO_DEFAULT;
+
+        fb_info->fix.type = FB_TYPE_PACKED_PIXELS;
+        fb_info->fix.visual = FB_VISUAL_TRUECOLOR;
+        fb_info->fix.line_length = msmfb->xres * 2;
+
+        fb_info->var.xres = msmfb->xres;
+        fb_info->var.yres = msmfb->yres;
+        fb_info->var.width = msmfb->panel->fb_data->width;
+        fb_info->var.height = msmfb->panel->fb_data->height;
+        fb_info->var.xres_virtual = msmfb->xres;
+        fb_info->var.yres_virtual = msmfb->yres * 2;
+        fb_info->var.bits_per_pixel = BITS_PER_PIXEL;
+        fb_info->var.accel_flags = 0;
+
+        fb_info->var.yoffset = 0;
+
+        if (msmfb->panel->caps & MSMFB_CAP_PARTIAL_UPDATES) {
+                fb_info->var.reserved[0] = 0x54445055;
+                fb_info->var.reserved[1] = 0;
+                fb_info->var.reserved[2] = (uint16_t)msmfb->xres |
+                                           ((uint32_t)msmfb->yres << 16);
+        }
+
+        fb_info->var.red.offset = 11;
+        fb_info->var.red.length = 5;
+        fb_info->var.red.msb_right = 0;
+        fb_info->var.green.offset = 5;
+        fb_info->var.green.length = 6;
+        fb_info->var.green.msb_right = 0;
+        fb_info->var.blue.offset = 0;
+        fb_info->var.blue.length = 5;
+        fb_info->var.blue.msb_right = 0;
+
+        r = fb_alloc_cmap(&fb_info->cmap, 16, 0);
+        fb_info->pseudo_palette = PP;
+
+        PP[0] = 0;
+        for (r = 1; r < 16; r++)
+                PP[r] = 0xffffffff;
+}
+
+static int setup_fbmem(struct msmfb_info *msmfb, struct platform_device *pdev)
+{
+        struct fb_info *fb = msmfb->fb;
+        struct resource *resource;
+        unsigned long size = msmfb->xres * msmfb->yres *
+                             (BITS_PER_PIXEL >> 3) * 2;
+        unsigned char *fbram;
+
+        /* board file might have attached a resource describing an fb */
+        resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!resource)
+                return -EINVAL;
+
+        /* check the resource is large enough to fit the fb */
+        if (resource->end - resource->start < size) {
+                printk(KERN_ERR "allocated resource is too small for "
+                                "fb\n");
+                return -ENOMEM;
+        }
+        fb->fix.smem_start = resource->start;
+        fb->fix.smem_len = resource->end - resource->start;
+        fbram = ioremap(resource->start,
+                        resource->end - resource->start);
+        if (fbram == 0) {
+                printk(KERN_ERR "msmfb: cannot allocate fbram!\n");
+                return -ENOMEM;
+        }
+        fb->screen_base = fbram;
+        return 0;
+}
+
+static int msmfb_probe(struct platform_device *pdev)
+{
+        struct fb_info *fb;
+        struct msmfb_info *msmfb;
+        struct msm_panel_data *panel = pdev->dev.platform_data;
+        int ret;
+
+        if (!panel) {
+                pr_err("msmfb_probe: no platform data\n");
+                return -EINVAL;
+        }
+        if (!panel->fb_data) {
+                pr_err("msmfb_probe: no fb_data\n");
+                return -EINVAL;
+        }
+
+        fb = framebuffer_alloc(sizeof(struct msmfb_info), &pdev->dev);
+        if (!fb)
+                return -ENOMEM;
+        msmfb = fb->par;
+        msmfb->fb = fb;
+        msmfb->panel = panel;
+        msmfb->xres = panel->fb_data->xres;
+        msmfb->yres = panel->fb_data->yres;
+
+        ret = setup_fbmem(msmfb, pdev);
+        if (ret)
+                goto error_setup_fbmem;
+
+        setup_fb_info(msmfb);
+
+        spin_lock_init(&msmfb->update_lock);
+        mutex_init(&msmfb->panel_init_lock);
+        init_waitqueue_head(&msmfb->frame_wq);
+        msmfb->resume_workqueue = create_workqueue("panel_on");
+        if (msmfb->resume_workqueue == NULL) {
+                printk(KERN_ERR "failed to create panel_on workqueue\n");
+                ret = -ENOMEM;
+                goto error_create_workqueue;
+        }
+        INIT_WORK(&msmfb->resume_work, power_on_panel);
+        msmfb->black = kzalloc(msmfb->fb->var.bits_per_pixel*msmfb->xres,
+                               GFP_KERNEL);
+
+        printk(KERN_INFO "msmfb_probe() installing %d x %d panel\n",
+               msmfb->xres, msmfb->yres);
+
+        msmfb->dma_callback.func = msmfb_handle_dma_interrupt;
+        msmfb->vsync_callback.func = msmfb_handle_vsync_interrupt;
+        hrtimer_init(&msmfb->fake_vsync, CLOCK_MONOTONIC,
+                     HRTIMER_MODE_REL);
+
+
+        msmfb->fake_vsync.function = msmfb_fake_vsync;
+
+        ret = register_framebuffer(fb);
+        if (ret)
+                goto error_register_framebuffer;
+
+        msmfb->sleeping = WAKING;
+
+        return 0;
+
+error_register_framebuffer:
+        destroy_workqueue(msmfb->resume_workqueue);
+error_create_workqueue:
+        iounmap(fb->screen_base);
+error_setup_fbmem:
+        framebuffer_release(msmfb->fb);
+        return ret;
+}
+
+static struct platform_driver msm_panel_driver = {
+        /* need to write remove */
+        .probe = msmfb_probe,
+        .driver = {.name = "msm_panel"},
+};
+
+
+static int msmfb_add_mdp_device(struct device *dev,
+                                struct class_interface *class_intf)
+{
+        /* might need locking if mulitple mdp devices */
+        if (mdp)
+                return 0;
+        mdp = container_of(dev, struct mdp_device, dev);
+        return platform_driver_register(&msm_panel_driver);
+}
+
+static void msmfb_remove_mdp_device(struct device *dev,
+                                struct class_interface *class_intf)
+{
+        /* might need locking if mulitple mdp devices */
+        if (dev != &mdp->dev)
+                return;
+        platform_driver_unregister(&msm_panel_driver);
+        mdp = NULL;
+}
+
+static struct class_interface msm_fb_interface = {
+        .add_dev = &msmfb_add_mdp_device,
+        .remove_dev = &msmfb_remove_mdp_device,
+};
+
+static int __init msmfb_init(void)
+{
+        return register_mdp_client(&msm_fb_interface);
+}
+
+module_init(msmfb_init);