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_priv.h"
  24 #include "hda_i915.h"
  25
  26 /* Intel HSW/BDW display HDA controller Extended Mode registers.
  27  * EM4 (M value) and EM5 (N Value) are used to convert CDClk (Core Display
  28  * Clock) to 24MHz BCLK: BCLK = CDCLK * M / N
  29  * The values will be lost when the display power well is disabled.
  30  */
  31 #define ICH6_REG_EM4                    0x100c
  32 #define ICH6_REG_EM5                    0x1010
  33
  34 static int (*get_power)(void);
  35 static int (*put_power)(void);
  36 static int (*get_cdclk)(void);
  37
  38 int hda_display_power(bool enable)
  39 {
  40         if (!get_power || !put_power)
  41                 return -ENODEV;
  42
  43         pr_debug("HDA display power %s \n",
  44                         enable ? "Enable" : "Disable");
  45         if (enable)
  46                 return get_power();
  47         else
  48                 return put_power();
  49 }
  50
  51 void haswell_set_bclk(struct azx *chip)
  52 {
  53         int cdclk_freq;
  54         unsigned int bclk_m, bclk_n;
  55
  56         if (!get_cdclk)
  57                 return;
  58
  59         cdclk_freq = get_cdclk();
  60         switch (cdclk_freq) {
  61         case 337500:
  62                 bclk_m = 16;
  63                 bclk_n = 225;
  64                 break;
  65
  66         case 450000:
  67         default: /* default CDCLK 450MHz */
  68                 bclk_m = 4;
  69                 bclk_n = 75;
  70                 break;
  71
  72         case 540000:
  73                 bclk_m = 4;
  74                 bclk_n = 90;
  75                 break;
  76
  77         case 675000:
  78                 bclk_m = 8;
  79                 bclk_n = 225;
  80                 break;
  81         }
  82
  83         azx_writew(chip, EM4, bclk_m);
  84         azx_writew(chip, EM5, bclk_n);
  85 }
  86
  87
  88 int hda_i915_init(void)
  89 {
  90         int err = 0;
  91
  92         get_power = symbol_request(i915_request_power_well);
  93         if (!get_power) {
  94                 pr_warn("hda-i915: get_power symbol get fail\n");
  95                 return -ENODEV;
  96         }
  97
  98         put_power = symbol_request(i915_release_power_well);
  99         if (!put_power) {
 100                 symbol_put(i915_request_power_well);
 101                 get_power = NULL;
 102                 return -ENODEV;
 103         }
 104
 105         get_cdclk = symbol_request(i915_get_cdclk_freq);
 106         if (!get_cdclk) /* may have abnormal BCLK and audio playback rate */
 107                 pr_warn("hda-i915: get_cdclk symbol get fail\n");
 108
 109         pr_debug("HDA driver get symbol successfully from i915 module\n");
 110
 111         return err;
 112 }
 113
 114 int hda_i915_exit(void)
 115 {
 116         if (get_power) {
 117                 symbol_put(i915_request_power_well);
 118                 get_power = NULL;
 119         }
 120         if (put_power) {
 121                 symbol_put(i915_release_power_well);
 122                 put_power = NULL;
 123         }
 124         if (get_cdclk) {
 125                 symbol_put(i915_get_cdclk_freq);
 126                 get_cdclk = NULL;
 127         }
 128
 129         return 0;
 130 }