linux/sound/pci/hda/hda_i915.c

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/*
* hda_i915.c - routines for Haswell HDA controller power well support
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <sound/core.h>
#include <drm/i915_powerwell.h>
#include "hda_priv.h"
#include "hda_i915.h"
/* Intel HSW/BDW display HDA controller Extended Mode registers.
* EM4 (M value) and EM5 (N Value) are used to convert CDClk (Core Display
* Clock) to 24MHz BCLK: BCLK = CDCLK * M / N
* The values will be lost when the display power well is disabled.
*/
#define AZX_REG_EM4 0x100c
#define AZX_REG_EM5 0x1010
static int (*get_power)(void);
static int (*put_power)(void);
static int (*get_cdclk)(void);
int hda_display_power(bool enable)
{
if (!get_power || !put_power)
return -ENODEV;
pr_debug("HDA display power %s \n",
enable ? "Enable" : "Disable");
if (enable)
return get_power();
else
return put_power();
}
void haswell_set_bclk(struct azx *chip)
{
int cdclk_freq;
unsigned int bclk_m, bclk_n;
if (!get_cdclk)
return;
cdclk_freq = get_cdclk();
switch (cdclk_freq) {
case 337500:
bclk_m = 16;
bclk_n = 225;
break;
case 450000:
default: /* default CDCLK 450MHz */
bclk_m = 4;
bclk_n = 75;
break;
case 540000:
bclk_m = 4;
bclk_n = 90;
break;
case 675000:
bclk_m = 8;
bclk_n = 225;
break;
}
azx_writew(chip, EM4, bclk_m);
azx_writew(chip, EM5, bclk_n);
}
int hda_i915_init(void)
{
int err = 0;
get_power = symbol_request(i915_request_power_well);
if (!get_power) {
pr_warn("hda-i915: get_power symbol get fail\n");
return -ENODEV;
}
put_power = symbol_request(i915_release_power_well);
if (!put_power) {
symbol_put(i915_request_power_well);
get_power = NULL;
return -ENODEV;
}
get_cdclk = symbol_request(i915_get_cdclk_freq);
if (!get_cdclk) /* may have abnormal BCLK and audio playback rate */
pr_warn("hda-i915: get_cdclk symbol get fail\n");
pr_debug("HDA driver get symbol successfully from i915 module\n");
return err;
}
int hda_i915_exit(void)
{
if (get_power) {
symbol_put(i915_request_power_well);
get_power = NULL;
}
if (put_power) {
symbol_put(i915_release_power_well);
put_power = NULL;
}
if (get_cdclk) {
symbol_put(i915_get_cdclk_freq);
get_cdclk = NULL;
}
return 0;
}