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 static int (*get_cdclk)(void);
  28
  29 int hda_display_power(bool enable)
  30 {
  31         if (!get_power || !put_power)
  32                 return -ENODEV;
  33
  34         snd_printdd("HDA display power %s \n",
  35                         enable ? "Enable" : "Disable");
  36         if (enable)
  37                 return get_power();
  38         else
  39                 return put_power();
  40 }
  41
  42 int haswell_get_cdclk(void)
  43 {
  44         if (!get_cdclk)
  45                 return -EINVAL;
  46         return get_cdclk();
  47 }
  48
  49 int hda_i915_init(void)
  50 {
  51         int err = 0;
  52
  53         get_power = symbol_request(i915_request_power_well);
  54         if (!get_power) {
  55                 snd_printk(KERN_WARNING "hda-i915: get_power symbol get fail\n");
  56                 return -ENODEV;
  57         }
  58
  59         put_power = symbol_request(i915_release_power_well);
  60         if (!put_power) {
  61                 symbol_put(i915_request_power_well);
  62                 get_power = NULL;
  63                 return -ENODEV;
  64         }
  65
  66         get_cdclk = symbol_request(i915_get_cdclk_freq);
  67         if (!get_cdclk) /* may have abnormal BCLK and audio playback rate */
  68                 snd_printd("hda-i915: get_cdclk symbol get fail\n");
  69
  70         snd_printd("HDA driver get symbol successfully from i915 module\n");
  71
  72         return err;
  73 }
  74
  75 int hda_i915_exit(void)
  76 {
  77         if (get_power) {
  78                 symbol_put(i915_request_power_well);
  79                 get_power = NULL;
  80         }
  81         if (put_power) {
  82                 symbol_put(i915_release_power_well);
  83                 put_power = NULL;
  84         }
  85         if (get_cdclk) {
  86                 symbol_put(i915_get_cdclk_freq);
  87                 get_cdclk = NULL;
  88         }
  89
  90         return 0;
  91 }