sound/pci/hda/hda_i915.c

   1 /*
   2  *  hda_i915.c - routines for Haswell HDA controller power well support
   3  *
   4  *  This program is free software; you can redistribute it and/or modify it
   5  *  under the terms of the GNU General Public License as published by the Free
   6  *  Software Foundation; either version 2 of the License, or (at your option)
   7  *  any later version.
   8  *
   9  *  This program is distributed in the hope that it will be useful, but
  10  *  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  11  *  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  *  for more details.
  13  *
  14  *  You should have received a copy of the GNU General Public License
  15  *  along with this program; if not, write to the Free Software Foundation,
  16  *  Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18
  19 #include <linux/init.h>
  20 #include <linux/module.h>
  21 #include <sound/core.h>
  22 #include <drm/i915_powerwell.h>
  23 #include "hda_i915.h"
  24
  25 static int (*get_power)(void);
  26 static int (*put_power)(void);
  27
  28 int hda_display_power(bool enable)
  29 {
  30         if (!get_power || !put_power)
  31                 return -ENODEV;
  32
  33         pr_debug("HDA display power %s \n",
  34                         enable ? "Enable" : "Disable");
  35         if (enable)
  36                 return get_power();
  37         else
  38                 return put_power();
  39 }
  40
  41 int hda_i915_init(void)
  42 {
  43         int err = 0;
  44
  45         get_power = symbol_request(i915_request_power_well);
  46         if (!get_power) {
  47                 pr_warn("hda-i915: get_power symbol get fail\n");
  48                 return -ENODEV;
  49         }
  50
  51         put_power = symbol_request(i915_release_power_well);
  52         if (!put_power) {
  53                 symbol_put(i915_request_power_well);
  54                 get_power = NULL;
  55                 return -ENODEV;
  56         }
  57
  58         pr_debug("HDA driver get symbol successfully from i915 module\n");
  59
  60         return err;
  61 }
  62
  63 int hda_i915_exit(void)
  64 {
  65         if (get_power) {
  66                 symbol_put(i915_request_power_well);
  67                 get_power = NULL;
  68         }
  69         if (put_power) {
  70                 symbol_put(i915_release_power_well);
  71                 put_power = NULL;
  72         }
  73
  74         return 0;
  75 }