drivers/gpu/drm/gma500/blitter.c

   1 /*
   2  * Copyright (c) 2014, Patrik Jakobsson
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * Authors: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
  15  */
  16
  17 #include "psb_drv.h"
  18
  19 #include "blitter.h"
  20 #include "psb_reg.h"
  21
  22 /* Wait for the blitter to be completely idle */
  23 int gma_blt_wait_idle(struct drm_psb_private *dev_priv)
  24 {
  25         unsigned long stop = jiffies + HZ;
  26         int busy = 1;
  27
  28         /* NOP for Cedarview */
  29         if (IS_CDV(dev_priv->dev))
  30                 return 0;
  31
  32         /* First do a quick check */
  33         if ((PSB_RSGX32(PSB_CR_2D_SOCIF) == _PSB_C2_SOCIF_EMPTY) &&
  34             ((PSB_RSGX32(PSB_CR_2D_BLIT_STATUS) & _PSB_C2B_STATUS_BUSY) == 0))
  35                 return 0;
  36
  37         do {
  38                 busy = (PSB_RSGX32(PSB_CR_2D_SOCIF) != _PSB_C2_SOCIF_EMPTY);
  39         } while (busy && !time_after_eq(jiffies, stop));
  40
  41         if (busy)
  42                 return -EBUSY;
  43
  44         do {
  45                 busy = ((PSB_RSGX32(PSB_CR_2D_BLIT_STATUS) &
  46                         _PSB_C2B_STATUS_BUSY) != 0);
  47         } while (busy && !time_after_eq(jiffies, stop));
  48
  49         /* If still busy, we probably have a hang */
  50         return (busy) ? -EBUSY : 0;
  51 }