181 строка
4.3 KiB
C
181 строка
4.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* hdac_i915.c - routines for sync between HD-A core and i915 display driver
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/pci.h>
|
|
#include <sound/core.h>
|
|
#include <sound/hdaudio.h>
|
|
#include <sound/hda_i915.h>
|
|
#include <sound/hda_register.h>
|
|
|
|
/**
|
|
* snd_hdac_i915_set_bclk - Reprogram BCLK for HSW/BDW
|
|
* @bus: HDA core bus
|
|
*
|
|
* Intel HSW/BDW display HDA controller is in GPU. Both its power and link BCLK
|
|
* depends on GPU. Two 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 and need to
|
|
* be restored to avoid abnormal playback speed.
|
|
*
|
|
* Call this function at initializing and changing power well, as well as
|
|
* at ELD notifier for the hotplug.
|
|
*/
|
|
void snd_hdac_i915_set_bclk(struct hdac_bus *bus)
|
|
{
|
|
struct drm_audio_component *acomp = bus->audio_component;
|
|
struct pci_dev *pci = to_pci_dev(bus->dev);
|
|
int cdclk_freq;
|
|
unsigned int bclk_m, bclk_n;
|
|
|
|
if (!acomp || !acomp->ops || !acomp->ops->get_cdclk_freq)
|
|
return; /* only for i915 binding */
|
|
if (!HDA_CONTROLLER_IS_HSW(pci))
|
|
return; /* only HSW/BDW */
|
|
|
|
cdclk_freq = acomp->ops->get_cdclk_freq(acomp->dev);
|
|
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;
|
|
}
|
|
|
|
snd_hdac_chip_writew(bus, HSW_EM4, bclk_m);
|
|
snd_hdac_chip_writew(bus, HSW_EM5, bclk_n);
|
|
}
|
|
EXPORT_SYMBOL_GPL(snd_hdac_i915_set_bclk);
|
|
|
|
/* returns true if the devices can be connected for audio */
|
|
static bool connectivity_check(struct pci_dev *i915, struct pci_dev *hdac)
|
|
{
|
|
struct pci_bus *bus_a = i915->bus, *bus_b = hdac->bus;
|
|
|
|
/* directly connected on the same bus */
|
|
if (bus_a == bus_b)
|
|
return true;
|
|
|
|
bus_a = bus_a->parent;
|
|
bus_b = bus_b->parent;
|
|
|
|
/* connected via parent bus (may be NULL!) */
|
|
if (bus_a == bus_b)
|
|
return true;
|
|
|
|
if (!bus_a || !bus_b)
|
|
return false;
|
|
|
|
/*
|
|
* on i915 discrete GPUs with embedded HDA audio, the two
|
|
* devices are connected via 2nd level PCI bridge
|
|
*/
|
|
bus_a = bus_a->parent;
|
|
bus_b = bus_b->parent;
|
|
if (bus_a && bus_a == bus_b)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
static int i915_component_master_match(struct device *dev, int subcomponent,
|
|
void *data)
|
|
{
|
|
struct pci_dev *hdac_pci, *i915_pci;
|
|
struct hdac_bus *bus = data;
|
|
|
|
if (!dev_is_pci(dev))
|
|
return 0;
|
|
|
|
hdac_pci = to_pci_dev(bus->dev);
|
|
i915_pci = to_pci_dev(dev);
|
|
|
|
if (!strcmp(dev->driver->name, "i915") &&
|
|
subcomponent == I915_COMPONENT_AUDIO &&
|
|
connectivity_check(i915_pci, hdac_pci))
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* check whether Intel graphics is present and reachable */
|
|
static int i915_gfx_present(struct pci_dev *hdac_pci)
|
|
{
|
|
struct pci_dev *display_dev = NULL;
|
|
|
|
for_each_pci_dev(display_dev) {
|
|
if (display_dev->vendor == PCI_VENDOR_ID_INTEL &&
|
|
(display_dev->class >> 16) == PCI_BASE_CLASS_DISPLAY &&
|
|
connectivity_check(display_dev, hdac_pci)) {
|
|
pci_dev_put(display_dev);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* snd_hdac_i915_init - Initialize i915 audio component
|
|
* @bus: HDA core bus
|
|
*
|
|
* This function is supposed to be used only by a HD-audio controller
|
|
* driver that needs the interaction with i915 graphics.
|
|
*
|
|
* This function initializes and sets up the audio component to communicate
|
|
* with i915 graphics driver.
|
|
*
|
|
* Returns zero for success or a negative error code.
|
|
*/
|
|
int snd_hdac_i915_init(struct hdac_bus *bus)
|
|
{
|
|
struct drm_audio_component *acomp;
|
|
int err;
|
|
|
|
if (!i915_gfx_present(to_pci_dev(bus->dev)))
|
|
return -ENODEV;
|
|
|
|
err = snd_hdac_acomp_init(bus, NULL,
|
|
i915_component_master_match,
|
|
sizeof(struct i915_audio_component) - sizeof(*acomp));
|
|
if (err < 0)
|
|
return err;
|
|
acomp = bus->audio_component;
|
|
if (!acomp)
|
|
return -ENODEV;
|
|
if (!acomp->ops) {
|
|
if (!IS_ENABLED(CONFIG_MODULES) ||
|
|
!request_module("i915")) {
|
|
/* 60s timeout */
|
|
wait_for_completion_killable_timeout(&acomp->master_bind_complete,
|
|
msecs_to_jiffies(60 * 1000));
|
|
}
|
|
}
|
|
if (!acomp->ops) {
|
|
dev_info(bus->dev, "couldn't bind with audio component\n");
|
|
snd_hdac_acomp_exit(bus);
|
|
return -ENODEV;
|
|
}
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(snd_hdac_i915_init);
|