209 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * hdac_i915.c - routines for sync between HD-A core and i915 display driver4 */5 6#include <linux/init.h>7#include <linux/module.h>8#include <linux/pci.h>9#include <sound/core.h>10#include <sound/hdaudio.h>11#include <sound/hda_i915.h>12#include <sound/hda_register.h>13#include <video/nomodeset.h>14 15static int gpu_bind = -1;16module_param(gpu_bind, int, 0644);17MODULE_PARM_DESC(gpu_bind, "Whether to bind sound component to GPU "18 "(1=always, 0=never, -1=on nomodeset(default))");19 20/**21 * snd_hdac_i915_set_bclk - Reprogram BCLK for HSW/BDW22 * @bus: HDA core bus23 *24 * Intel HSW/BDW display HDA controller is in GPU. Both its power and link BCLK25 * depends on GPU. Two Extended Mode registers EM4 (M value) and EM5 (N Value)26 * are used to convert CDClk (Core Display Clock) to 24MHz BCLK:27 * BCLK = CDCLK * M / N28 * The values will be lost when the display power well is disabled and need to29 * be restored to avoid abnormal playback speed.30 *31 * Call this function at initializing and changing power well, as well as32 * at ELD notifier for the hotplug.33 */34void snd_hdac_i915_set_bclk(struct hdac_bus *bus)35{36 struct drm_audio_component *acomp = bus->audio_component;37 struct pci_dev *pci = to_pci_dev(bus->dev);38 int cdclk_freq;39 unsigned int bclk_m, bclk_n;40 41 if (!acomp || !acomp->ops || !acomp->ops->get_cdclk_freq)42 return; /* only for i915 binding */43 if (!HDA_CONTROLLER_IS_HSW(pci))44 return; /* only HSW/BDW */45 46 cdclk_freq = acomp->ops->get_cdclk_freq(acomp->dev);47 switch (cdclk_freq) {48 case 337500:49 bclk_m = 16;50 bclk_n = 225;51 break;52 53 case 450000:54 default: /* default CDCLK 450MHz */55 bclk_m = 4;56 bclk_n = 75;57 break;58 59 case 540000:60 bclk_m = 4;61 bclk_n = 90;62 break;63 64 case 675000:65 bclk_m = 8;66 bclk_n = 225;67 break;68 }69 70 snd_hdac_chip_writew(bus, HSW_EM4, bclk_m);71 snd_hdac_chip_writew(bus, HSW_EM5, bclk_n);72}73EXPORT_SYMBOL_GPL(snd_hdac_i915_set_bclk);74 75/* returns true if the devices can be connected for audio */76static bool connectivity_check(struct pci_dev *i915, struct pci_dev *hdac)77{78 struct pci_bus *bus_a = i915->bus, *bus_b = hdac->bus;79 80 /* directly connected on the same bus */81 if (bus_a == bus_b)82 return true;83 84 bus_a = bus_a->parent;85 bus_b = bus_b->parent;86 87 /* connected via parent bus (may be NULL!) */88 if (bus_a == bus_b)89 return true;90 91 if (!bus_a || !bus_b)92 return false;93 94 /*95 * on i915 discrete GPUs with embedded HDA audio, the two96 * devices are connected via 2nd level PCI bridge97 */98 bus_a = bus_a->parent;99 bus_b = bus_b->parent;100 if (bus_a && bus_a == bus_b)101 return true;102 103 return false;104}105 106static int i915_component_master_match(struct device *dev, int subcomponent,107 void *data)108{109 struct pci_dev *hdac_pci, *i915_pci;110 struct hdac_bus *bus = data;111 112 if (!dev_is_pci(dev))113 return 0;114 115 hdac_pci = to_pci_dev(bus->dev);116 i915_pci = to_pci_dev(dev);117 118 if ((!strcmp(dev->driver->name, "i915") ||119 !strcmp(dev->driver->name, "xe")) &&120 subcomponent == I915_COMPONENT_AUDIO &&121 connectivity_check(i915_pci, hdac_pci))122 return 1;123 124 return 0;125}126 127/* check whether Intel graphics is present and reachable */128static int i915_gfx_present(struct pci_dev *hdac_pci)129{130 /* List of known platforms with no i915 support. */131 static const struct pci_device_id denylist[] = {132 /* CNL */133 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x5a40), 0x030000, 0xff0000 },134 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x5a41), 0x030000, 0xff0000 },135 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x5a42), 0x030000, 0xff0000 },136 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x5a44), 0x030000, 0xff0000 },137 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x5a49), 0x030000, 0xff0000 },138 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x5a4a), 0x030000, 0xff0000 },139 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x5a4c), 0x030000, 0xff0000 },140 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x5a50), 0x030000, 0xff0000 },141 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x5a51), 0x030000, 0xff0000 },142 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x5a52), 0x030000, 0xff0000 },143 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x5a54), 0x030000, 0xff0000 },144 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x5a59), 0x030000, 0xff0000 },145 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x5a5a), 0x030000, 0xff0000 },146 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x5a5c), 0x030000, 0xff0000 },147 /* LKF */148 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x9840), 0x030000, 0xff0000 },149 {}150 };151 struct pci_dev *display_dev = NULL;152 153 if (!gpu_bind || (gpu_bind < 0 && video_firmware_drivers_only()))154 return false;155 156 for_each_pci_dev(display_dev) {157 if (display_dev->vendor != PCI_VENDOR_ID_INTEL ||158 (display_dev->class >> 16) != PCI_BASE_CLASS_DISPLAY)159 continue;160 161 if (pci_match_id(denylist, display_dev))162 continue;163 164 if (connectivity_check(display_dev, hdac_pci)) {165 pci_dev_put(display_dev);166 return true;167 }168 }169 170 return false;171}172 173/**174 * snd_hdac_i915_init - Initialize i915 audio component175 * @bus: HDA core bus176 *177 * This function is supposed to be used only by a HD-audio controller178 * driver that needs the interaction with i915 graphics.179 *180 * This function initializes and sets up the audio component to communicate181 * with i915 graphics driver.182 *183 * Returns zero for success or a negative error code.184 */185int snd_hdac_i915_init(struct hdac_bus *bus)186{187 struct drm_audio_component *acomp;188 int err;189 190 if (!i915_gfx_present(to_pci_dev(bus->dev)))191 return -ENODEV;192 193 err = snd_hdac_acomp_init(bus, NULL,194 i915_component_master_match,195 sizeof(struct i915_audio_component) - sizeof(*acomp));196 if (err < 0)197 return err;198 acomp = bus->audio_component;199 if (!acomp)200 return -ENODEV;201 if (!acomp->ops) {202 snd_hdac_acomp_exit(bus);203 return dev_err_probe(bus->dev, -EPROBE_DEFER,204 "couldn't bind with audio component\n");205 }206 return 0;207}208EXPORT_SYMBOL_GPL(snd_hdac_i915_init);209