return -EINVAL;
 
        parent = clk->parent;
-       if (unlikely(parent == 0))
+       if (unlikely(parent == NULL))
                return -EIO;
 
        realrate = parent->rate;
        if (clk->flags & ALWAYS_ENABLED)
                return 0;
 
-       if (unlikely(clk->enable_reg == 0)) {
+       if (unlikely(clk->enable_reg == NULL)) {
                printk(KERN_ERR "clock.c: Enable for %s without enable code\n",
                       clk->name);
                return -EINVAL;
        __u16 regval16;
        __u32 regval32;
 
-       if (clk->enable_reg == 0)
+       if (clk->enable_reg == NULL)
                return;
 
        if (clk->flags & ENABLE_REG_32BIT) {
                return clk->parent->rate / (1 << dsor_exp);
        }
 
-       if(clk->round_rate != 0)
+       if (clk->round_rate != NULL)
                return clk->round_rate(clk, rate);
 
        return clk->rate;
 
        if (clk->enable)
                return clk->enable(clk);
 
-       if (!clk->enable_reg) {
+       if (unlikely(clk->enable_reg == NULL)) {
                printk(KERN_ERR "clock.c: Enable for %s without enable code\n",
                       clk->name);
                return 0; /* REVISIT: -EINVAL */
                return;
        }
 
-       if (!clk->enable_reg) {
+       if (clk->enable_reg == NULL) {
                /*
                 * 'Independent' here refers to a clock which is not
                 * controlled by its parent.
 /* Given a clock and a rate apply a clock specific rounding function */
 long omap2_clk_round_rate(struct clk *clk, unsigned long rate)
 {
-       if (clk->round_rate)
+       if (clk->round_rate != NULL)
                return clk->round_rate(clk, rate);
 
        if (clk->flags & RATE_FIXED)
  */
 static void __iomem *omap2_get_clksel(struct clk *clk, u32 *field_mask)
 {
-       if (!clk->clksel_reg || (clk->clksel_mask == 0))
+       if (unlikely((clk->clksel_reg == NULL) || (clk->clksel_mask == NULL)))
                return NULL;
 
        *field_mask = clk->clksel_mask;
        void __iomem *div_addr;
 
        div_addr = omap2_get_clksel(clk, &field_mask);
-       if (!div_addr)
+       if (div_addr == NULL)
                return 0;
 
        field_val = __raw_readl(div_addr) & field_mask;
                return -EINVAL;
 
        div_addr = omap2_get_clksel(clk, &field_mask);
-       if (!div_addr)
+       if (div_addr == NULL)
                return -EINVAL;
 
        field_val = omap2_divisor_to_clksel(clk, new_div);
                return -EINVAL;
 
        /* dpll_ck, core_ck, virt_prcm_set; plus all clksel clocks */
-       if (clk->set_rate)
+       if (clk->set_rate != NULL)
                ret = clk->set_rate(clk, rate);
 
        if (ret == 0 && (clk->flags & RATE_PROPAGATES))
 
        field_val = omap2_clksel_get_src_field(&src_addr, new_parent,
                                               &field_mask, clk, &parent_div);
-       if (!src_addr)
+       if (src_addr == NULL)
                return -EINVAL;
 
        if (clk->usecount > 0)
 
        /* request and reserve DMA channels for the chain */
        for (i = 0; i < no_of_chans; i++) {
                err = omap_request_dma(dev_id, dev_name,
-                                       callback, 0, &channels[i]);
+                                       callback, NULL, &channels[i]);
                if (err < 0) {
                        int j;
                        for (j = 0; j < i; j++)
 
        int ret;
 
        omapfb_rqueue_lock(plane->fbdev);
-       ret = omapfb_update_window_async(fbi, win, NULL, 0);
+       ret = omapfb_update_window_async(fbi, win, NULL, NULL);
        omapfb_rqueue_unlock(plane->fbdev);
 
        return ret;
        win.format = 0;
 
        omapfb_rqueue_lock(fbdev);
-       r = fbdev->ctrl->update_window(fbi, &win, NULL, 0);
+       r = fbdev->ctrl->update_window(fbi, &win, NULL, NULL);
        omapfb_rqueue_unlock(fbdev);
 
        return r;
                win.height = 2;
                win.out_width = 2;
                win.out_height = 2;
-               fbdev->ctrl->update_window(fbdev->fb_info[0], &win, NULL, 0);
+               fbdev->ctrl->update_window(fbdev->fb_info[0], &win, NULL, NULL);
        }
        omapfb_rqueue_unlock(fbdev);
 }